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• Specifying a Postfix Instance to send outbound email

  - by Catherine Jefferson

  I have a CentOS 6.5 server running Postfix 2.6x (the default distribution) with five public IPv4 IPs bound to it. Each IP has DNS and rDNS set separately. Each uses a different hostname at a different domain. I have five Postfix instances, one bound to each IP, like this example: 192.168.34.104 red.example.com /etc/postfix 192.168.36.48 green.example.net /etc/postfix-green 192.168.36.49 pink.example.org /etc/postfix-pink 192.168.36.50 orange.example.info /etc/postfix-orange 192.168.36.51 blue.example.us /etc/postfix-blue I've tested each IP by telneting to port 25. Postfix answers and banners properly with the correct hostname. Email is received on all of these instances with no problems and is routed to the correct place. This setup, minus the final instance, has existed for a couple of years and works. I never bothered to set up outbound email to go through any but the main instance, however; there was no need. Now I need to send email from blue.example.us that actually leaves from that interface and IP, such that the Received headers show blue.example.us as the sending mailhost, so that SPF and DKIM validate, etc etc. The email that will be sent from blue.example.com is a feedback loop sent by a single shell account on the server (account5), an account that is dedicated to sending this email. The account receives the feedback loop emails from servers on other networks, saves the bodies of those emails, and then generates a new outbound email header, appends the saved body, and sends the email. It's sending by piping each email to sendmail -oi -t. We're doing it this way to mask the identities of the initial servers. The procmail script that processes these emails works correctly. However, I cannot configure this account to send email through the proper Postfix instance/IP/interface. The exact same account and script sends email through the main Postfix instance /etc/postfix without any issues. When I change MAIL_CONFIG to point to /etc/postfix-blue in either .bash_profile or the Procmail script that handles this email, though, I get this error: sendmail: fatal: User account5(###) is not allowed to submit mail I've read the manuals on Postfix.org, searched Google, and tried the suggestions in three previous answers here on ServerFault.com: Postfix - specify interface to deliver outbound mail on Postfix user is not allowed to submit mail Postfix rejects php mails I have been careful to stop and restart Postfix after each configuration change, and tested the results. Nothing has worked. The main postfix instance happily accepts outbound email from account5. The postfix-blue instance continues to reject email from account5 with the sendmail error above. As tempting as it is to blame machine hostility, I know that I must be missing something or doing something wrong. Does anybody have any suggestions as to what it might be? Please feel free to ask for further information about my setup if you need it. =-=-=-=-=-=-=-=-=-= At the request of the responder, here are main.cf and master.cf for a) the main postfix instance ("red.example.com") and b) the FBL instance ("blue.example.us") [NOTE: All parameters not specified below were left at the default Postfix 2.6 settings] MAIN: master.cf smtp inet n - n - - smtpd main.cf myhostname = red.example.com mydomain = example.com inet_interfaces = $myhostname, localhost inet_protocols = all lmtp_host_lookup = native smtp_host_lookup = native ignore_mx_lookup_error = yes mydestination = $myhostname, localhost.$mydomain, localhost local_recipient_maps = mynetworks = 192.168.34.104/32 relay_domains = example.com, example.info, example.net, example.org, example.us relayhost = [192.168.34.102] # Separate physical server, main mailserver. relay_recipient_maps = hash:/etc/postfix/relay_recipients alias_maps = hash:/etc/aliases alias_database = hash:/etc/aliases smtpd_banner = $myhostname ESMTP $mail_name multi_instance_wrapper = ${command_directory}/postmulti -p -- multi_instance_enable = yes multi_instance_directories = /etc/postfix-green /etc/postfix-pink /etc/postfix-orange /etc/postfix-blue FBL: master.cf 184.173.119.103:25 inet n - n - - smtpd main.cf myhostname = blue.example.us mydomain = blue.example.us <= Deliberately set to subdomain only. myorigin = $mydomain inet_interfaces = $myhostname lmtp_host_lookup = native smtp_host_lookup = native ignore_mx_lookup_error = yes mydestination = $myhostname local_recipient_maps = unix:passwd.byname $alias_maps $virtual_alias_maps mynetworks = 192.168.36.51/32, 192.168.35.20/31 <= Second IP is backup MX servers relay_domains = $mydestination recipient_canonical_maps = hash:/etc/postfix-blue/canonical virtual_alias_maps = hash:/etc/postfix-fbl/virtual alias_maps = hash:/etc/aliases, hash:/etc/postfix-blue/canonical alias_maps = hash:/etc/aliases, hash:/etc/postfix-blue/canonical mailbox_command = /usr/bin/procmail -a "$EXTENSION" DEFAULT=$HOME/Mail/ MAILDIR=$HOME/Mail smtpd_banner = $myhostname ESMTP $mail_name authorized_submit_users = multi_instance_name = postfix-blue multi_instance_enable = yes

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• ActiveX component can't create Object Error? Check 64 bit Status

  - by Rick Strahl

  If you're running on IIS 7 and a 64 bit operating system you might run into the following error using ASP classic or ASP.NET with COM interop. In classic ASP applications the error will show up as: ActiveX component can't create object   (Error 429) (actually without error handling the error just shows up as 500 error page) In my case the code that's been giving me problems has been a FoxPro COM object I'd been using to serve banner ads to some of my pages. The code basically looks up banners from a database table and displays them at random. The ASP classic code that uses it looks like this: <% Set banner = Server.CreateObject("wwBanner.aspBanner") banner.BannerFile = "wwsitebanners" Response.Write(banner.GetBanner(-1)) %> Originally this code had no specific error checking as above so the ASP pages just failed with 500 error pages from the Web server. To find out what the problem is this code is more useful at least for debugging: <% ON ERROR RESUME NEXT Set banner = Server.CreateObject("wwBanner.aspBanner") Response.Write(err.Number & " - " & err.Description) banner.BannerFile = "wwsitebanners" Response.Write(banner.GetBanner(-1)) %> which results in: 429 - ActiveX component can't create object which at least gives you a slight clue. In ASP.NET invoking the same COM object with code like this: <% dynamic banner = wwUtils.CreateComInstance("wwBanner.aspBanner") as dynamic; banner.cBANNERFILE = "wwsitebanners"; Response.Write(banner.getBanner(-1)); %> results in: Retrieving the COM class factory for component with CLSID {B5DCBB81-D5F5-11D2-B85E-00600889F23B} failed due to the following error: 80040154 Class not registered (Exception from HRESULT: 0x80040154 (REGDB_E_CLASSNOTREG)). The class is in fact registered though and the COM server loads fine from a command prompt or other COM client. This error can be caused by a COM server that doesn't load. It looks like a COM registration error. There are a number of traditional reasons why this error can crop up of course. The server isn't registered (run regserver32 to register a DLL server or /regserver on an EXE server) Access permissions aren't set on the COM server (Web account has to be able to read the DLL ie. Network service) The COM server fails to load during initialization ie. failing during startup One thing I always do to check for COM errors fire up the server in a COM client outside of IIS and ensure that it works there first - it's almost always easier to debug a server outside of the Web environment. In my case I tried the server in Visual FoxPro on the server with: loBanners = CREATEOBJECT("wwBanner.aspBanner") loBanners.cBannerFile = "wwsitebanners" ? loBanners.GetBanner(-1) and it worked just fine. If you don't have a full dev environment on the server you can also use VBScript do the same thing and run the .vbs file from the command prompt: Set banner = Server.CreateObject("wwBanner.aspBanner") banner.BannerFile = "wwsitebanners" MsgBox(banner.getBanner(-1)) Since this both works it tells me the server is registered and working properly. This leaves startup failures or permissions as the problem. I double checked permissions for the Application Pool and the permissions of the folder where the DLL lives and both are properly set to allow access by the Application Pool impersonated user. Just to be sure I assigned an Admin user to the Application Pool but still no go. So now what? 64 bit Servers Ahoy A couple of weeks back I had set up a few of my Application pools to 64 bit mode. My server is Server 2008 64 bit and by default Application Pools run 64 bit. Originally when I installed the server I set up most of my Application Pools to 32 bit mainly for backwards compatibility. But as more of my code migrates to 64 bit OS's I figured it'd be a good idea to see how well code runs under 64 bit code. The transition has been mostly painless. Until today when I noticed the problem with the code above when scrolling to my IIS logs and noticing a lot of 500 errors on many of my ASP classic pages. The code in question in most of these pages deals with this single simple COM object. It took a while to figure out that the problem is caused by the Application Pool running in 64 bit mode. The issue is that 32 bit COM objects (ie. my old Visual FoxPro COM component) cannot be loaded in a 64 bit Application Pool. The ASP pages using this COM component broke on the day I switched my main Application Pool into 64 bit mode but I didn't find the problem until I searched my logs for errors by pure chance. To fix this is easy enough once you know what the problem is by switching the Application Pool to Enable 32-bit Applications: Once this is done the COM objects started working correctly again. 64 bit ASP and ASP.NET with DCOM Servers This is kind of off topic, but incidentally it's possible to load 32 bit DCOM (out of process) servers from ASP.NET and ASP classic even if those applications run in 64 bit application pools. In fact, in West Wind Web Connection I use this capability to run a 64 bit ASP.NET handler that talks to a 32 bit FoxPro COM server which allows West Wind Web Connection to run in native 64 bit mode without custom configuration (which is actually quite useful). It's probably not a common usage scenario but it's good to know that you can actually access 32 bit COM objects this way from ASP.NET. For West Wind Web Connection this works out well as the DCOM interface only makes one non-chatty call to the backend server that handles all the rest of the request processing. Application Pool Isolation is your Friend For me the recent incident of failure in the classic ASP pages has just been another reminder to be very careful with moving applications to 64 bit operation. There are many little traps when switching to 64 bit that are very difficult to track and test for. I described one issue I had a couple of months ago where one of the default ASP.NET filters was loading the wrong version (32bit instead of 64bit) which was extremely difficult to track down and was caused by a very sneaky configuration switch error (basically 3 different entries for the same ISAPI filter all with different bitness settings). It took me almost a full day to track this down). Recently I've been taken to isolate individual applications into separate Application Pools rather than my past practice of combining many apps into shared AppPools. This is a good practice assuming you have enough memory to make this work. Application Pool isolate provides more modularity and allows me to selectively move applications to 64 bit. The error above came about precisely because I moved one of my most populous app pools to 64 bit and forgot about the minimal COM object use in some of my old pages. It's easy to forget. To 64bit or Not Is it worth it to move to 64 bit? Currently I'd say -not really. In my - admittedly limited - testing I don't see any significant performance increases. In fact 64 bit apps just seem to consume considerably more memory (30-50% more in my pools on average) and performance is minimally improved (less than 5% at the very best) in the load testing I've performed on a couple of sites in both modes. The only real incentive for 64 bit would be applications that require huge data spaces that exceed the 32 bit 4 gigabyte memory limit. However I have a hard time imagining an application that needs 4 gigs of memory in a single Application Pool :-). Curious to hear other opinions on benefits of 64 bit operation. © Rick Strahl, West Wind Technologies, 2005-2011Posted in COM   ASP.NET  FoxPro  

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• LINQ to SQL and missing Many to Many EntityRefs

  - by Rick Strahl

  Ran into an odd behavior today with a many to many mapping of one of my tables in LINQ to SQL. Many to many mappings aren’t transparent in LINQ to SQL and it maps the link table the same way the SQL schema has it when creating one. In other words LINQ to SQL isn’t smart about many to many mappings and just treats it like the 3 underlying tables that make up the many to many relationship. Iain Galloway has a nice blog entry about Many to Many relationships in LINQ to SQL. I can live with that – it’s not really difficult to deal with this arrangement once mapped, especially when reading data back. Writing is a little more difficult as you do have to insert into two entities for new records, but nothing that can’t be handled in a small business object method with a few lines of code. When I created a database I’ve been using to experiment around with various different OR/Ms recently I found that for some reason LINQ to SQL was completely failing to map even to the linking table. As it turns out there’s a good reason why it fails, can you spot it below? (read on :-}) Here is the original database layout: There’s an items table, a category table and a link table that holds only the foreign keys to the Items and Category tables for a typical M->M relationship. When these three tables are imported into the model the *look* correct – I do get the relationships added (after modifying the entity names to strip the prefix): The relationship looks perfectly fine, both in the designer as well as in the XML document: <Table Name="dbo.wws_Item_Categories" Member="ItemCategories"> <Type Name="ItemCategory"> <Column Name="ItemId" Type="System.Guid" DbType="uniqueidentifier NOT NULL" CanBeNull="false" /> <Column Name="CategoryId" Type="System.Guid" DbType="uniqueidentifier NOT NULL" CanBeNull="false" /> <Association Name="ItemCategory_Category" Member="Categories" ThisKey="CategoryId" OtherKey="Id" Type="Category" /> <Association Name="Item_ItemCategory" Member="Item" ThisKey="ItemId" OtherKey="Id" Type="Item" IsForeignKey="true" /> </Type> </Table> <Table Name="dbo.wws_Categories" Member="Categories"> <Type Name="Category"> <Column Name="Id" Type="System.Guid" DbType="UniqueIdentifier NOT NULL" IsPrimaryKey="true" IsDbGenerated="true" CanBeNull="false" /> <Column Name="ParentId" Type="System.Guid" DbType="UniqueIdentifier" CanBeNull="true" /> <Column Name="CategoryName" Type="System.String" DbType="NVarChar(150)" CanBeNull="true" /> <Column Name="CategoryDescription" Type="System.String" DbType="NVarChar(MAX)" CanBeNull="true" /> <Column Name="tstamp" AccessModifier="Internal" Type="System.Data.Linq.Binary" DbType="rowversion" CanBeNull="true" IsVersion="true" /> <Association Name="ItemCategory_Category" Member="ItemCategory" ThisKey="Id" OtherKey="CategoryId" Type="ItemCategory" IsForeignKey="true" /> </Type> </Table> However when looking at the code generated these navigation properties (also on Item) are completely missing: [global::System.Data.Linq.Mapping.TableAttribute(Name="dbo.wws_Item_Categories")] [global::System.Runtime.Serialization.DataContractAttribute()] public partial class ItemCategory : Westwind.BusinessFramework.EntityBase { private System.Guid _ItemId; private System.Guid _CategoryId; public ItemCategory() { } [global::System.Data.Linq.Mapping.ColumnAttribute(Storage="_ItemId", DbType="uniqueidentifier NOT NULL")] [global::System.Runtime.Serialization.DataMemberAttribute(Order=1)] public System.Guid ItemId { get { return this._ItemId; } set { if ((this._ItemId != value)) { this._ItemId = value; } } } [global::System.Data.Linq.Mapping.ColumnAttribute(Storage="_CategoryId", DbType="uniqueidentifier NOT NULL")] [global::System.Runtime.Serialization.DataMemberAttribute(Order=2)] public System.Guid CategoryId { get { return this._CategoryId; } set { if ((this._CategoryId != value)) { this._CategoryId = value; } } } } Notice that the Item and Category association properties which should be EntityRef properties are completely missing. They’re there in the model, but the generated code – not so much. So what’s the problem here? The problem – it appears – is that LINQ to SQL requires primary keys on all entities it tracks. In order to support tracking – even of the link table entity – the link table requires a primary key. Real obvious ain’t it, especially since the designer happily lets you import the table and even shows the relationship and implicitly the related properties. Adding an Id field as a Pk to the database and then importing results in this model layout: which properly generates the Item and Category properties into the link entity. It’s ironic that LINQ to SQL *requires* the PK in the middle – the Entity Framework requires that a link table have *only* the two foreign key fields in a table in order to recognize a many to many relation. EF actually handles the M->M relation directly without the intermediate link entity unlike LINQ to SQL. [updated from comments – 12/24/2009] Another approach is to set up both ItemId and CategoryId in the database which shows up in LINQ to SQL like this: This also work in creating the Category and Item fields in the ItemCategory entity. Ultimately this is probably the best approach as it also guarantees uniqueness of the keys and so helps in database integrity. It took me a while to figure out WTF was going on here – lulled by the designer to think that the properties should be when they were not. It’s actually a well documented feature of L2S that each entity in the model requires a Pk but of course that’s easy to miss when the model viewer shows it to you and even the underlying XML model shows the Associations properly. This is one of the issue with L2S of course – you have to play by its rules and once you hit one of those rules there’s no way around them – you’re stuck with what it requires which in this case meant changing the database.© Rick Strahl, West Wind Technologies, 2005-2010Posted in ADO.NET  LINQ  

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• Creating a dynamic proxy generator with c# – Part 2 – Interceptor Design

  - by SeanMcAlinden

  Creating a dynamic proxy generator – Part 1 – Creating the Assembly builder, Module builder and caching mechanism For the latest code go to http://rapidioc.codeplex.com/ Before getting too involved in generating the proxy, I thought it would be worth while going through the intended design, this is important as the next step is to start creating the constructors for the proxy. Each proxy derives from a specified type The proxy has a corresponding constructor for each of the base type constructors The proxy has overrides for all methods and properties marked as Virtual on the base type For each overridden method, there is also a private method whose sole job is to call the base method. For each overridden method, a delegate is created whose sole job is to call the private method that calls the base method. The following class diagram shows the main classes and interfaces involved in the interception process. I’ll go through each of them to explain their place in the overall proxy.   IProxy Interface The proxy implements the IProxy interface for the sole purpose of adding custom interceptors. This allows the created proxy interface to be cast as an IProxy and then simply add Interceptors by calling it’s AddInterceptor method. This is done internally within the proxy building process so the consumer of the API doesn’t need knowledge of this. IInterceptor Interface The IInterceptor interface has one method: Handle. The handle method accepts a IMethodInvocation parameter which contains methods and data for handling method interception. Multiple classes that implement this interface can be added to the proxy. Each method override in the proxy calls the handle method rather than simply calling the base method. How the proxy fully works will be explained in the next section MethodInvocation. IMethodInvocation Interface & MethodInvocation class The MethodInvocation will contain one main method and multiple helper properties. Continue Method The method Continue() has two functions hidden away from the consumer. When Continue is called, if there are multiple Interceptors, the next Interceptors Handle method is called. If all Interceptors Handle methods have been called, the Continue method then calls the base class method. Properties The MethodInvocation will contain multiple helper properties including at least the following: Method Name (Read Only) Method Arguments (Read and Write) Method Argument Types (Read Only) Method Result (Read and Write) – this property remains null if the method return type is void Target Object (Read Only) Return Type (Read Only) DefaultInterceptor class The DefaultInterceptor class is a simple class that implements the IInterceptor interface. Here is the code: DefaultInterceptor namespace Rapid.DynamicProxy.Interception {     /// <summary>     /// Default interceptor for the proxy.     /// </summary>     /// <typeparam name="TBase">The base type.</typeparam>     public class DefaultInterceptor<TBase> : IInterceptor<TBase> where TBase : class     {         /// <summary>         /// Handles the specified method invocation.         /// </summary>         /// <param name="methodInvocation">The method invocation.</param>         public void Handle(IMethodInvocation<TBase> methodInvocation)         {             methodInvocation.Continue();         }     } } This is automatically created in the proxy and is the first interceptor that each method override calls. It’s sole function is to ensure that if no interceptors have been added, the base method is still called. Custom Interceptor Example A consumer of the Rapid.DynamicProxy API could create an interceptor for logging when the FirstName property of the User class is set. Just for illustration, I have also wrapped a transaction around the methodInvocation.Coninue() method. This means that any overriden methods within the user class will run within a transaction scope. MyInterceptor public class MyInterceptor : IInterceptor<User<int, IRepository>> {     public void Handle(IMethodInvocation<User<int, IRepository>> methodInvocation)     {         if (methodInvocation.Name == "set_FirstName")         {             Logger.Log("First name seting to: " + methodInvocation.Arguments[0]);         }         using (TransactionScope scope = new TransactionScope())         {             methodInvocation.Continue();         }         if (methodInvocation.Name == "set_FirstName")         {             Logger.Log("First name has been set to: " + methodInvocation.Arguments[0]);         }     } } Overridden Method Example To show a taster of what the overridden methods on the proxy would look like, the setter method for the property FirstName used in the above example would look something similar to the following (this is not real code but will look similar): set_FirstName public override void set_FirstName(string value) {     set_FirstNameBaseMethodDelegate callBase =         new set_FirstNameBaseMethodDelegate(this.set_FirstNameProxyGetBaseMethod);     object[] arguments = new object[] { value };     IMethodInvocation<User<IRepository>> methodInvocation =         new MethodInvocation<User<IRepository>>(this, callBase, "set_FirstName", arguments, interceptors);          this.Interceptors[0].Handle(methodInvocation); } As you can see, a delegate instance is created which calls to a private method on the class, the private method calls the base method and would look like the following: calls base setter private void set_FirstNameProxyGetBaseMethod(string value) {     base.set_FirstName(value); } The delegate is invoked when methodInvocation.Continue() is called within an interceptor. The set_FirstName parameters are loaded into an object array. The current instance, delegate, method name and method arguments are passed into the methodInvocation constructor (there will be more data not illustrated here passed in when created including method info, return types, argument types etc.) The DefaultInterceptor’s Handle method is called with the methodInvocation instance as it’s parameter. Obviously methods can have return values, ref and out parameters etc. in these cases the generated method override body will be slightly different from above. I’ll go into more detail on these aspects as we build them. Conclusion I hope this has been useful, I can’t guarantee that the proxy will look exactly like the above, but at the moment, this is pretty much what I intend to do. Always worth downloading the code at http://rapidioc.codeplex.com/ to see the latest. There will also be some tests that you can debug through to help see what’s going on. Cheers, Sean.

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• DropDownList and SelectListItem Array Item Updates in MVC

  - by Rick Strahl

  So I ran into an interesting behavior today as I deployed my first MVC 4 app tonight. I have a list form that has a filter drop down that allows selection of categories. This list is static and rarely changes so rather than loading these items from the database each time I load the items once and then cache the actual SelectListItem[] array in a static property. However, when we put the site online tonight we immediately noticed that the drop down list was coming up with pre-set values that randomly changed. Didn't take me long to trace this back to the cached list of SelectListItem[]. Clearly the list was getting updated - apparently through the model binding process in the selection postback. To clarify the scenario here's the drop down list definition in the Razor View:@Html.DropDownListFor(mod => mod.QueryParameters.Category, Model.CategoryList, "All Categories") where Model.CategoryList gets set with:[HttpPost] [CompressContent] public ActionResult List(MessageListViewModel model) { InitializeViewModel(model); busEntry entryBus = new busEntry(); var entries = entryBus.GetEntryList(model.QueryParameters); model.Entries = entries; model.DisplayMode = ApplicationDisplayModes.Standard; model.CategoryList = AppUtils.GetCachedCategoryList(); return View(model); } The AppUtils.GetCachedCategoryList() method gets the cached list or loads the list on the first access. The code to load up the list is housed in a Web utility class. The method looks like this:/// <summary> /// Returns a static category list that is cached /// </summary> /// <returns></returns> public static SelectListItem[] GetCachedCategoryList() { if (_CategoryList != null) return _CategoryList; lock (_SyncLock) { if (_CategoryList != null) return _CategoryList; var catBus = new busCategory(); var categories = catBus.GetCategories().ToList(); // Turn list into a SelectItem list var catList= categories .Select(cat => new SelectListItem() { Text = cat.Name, Value = cat.Id.ToString() }) .ToList(); catList.Insert(0, new SelectListItem() { Value = ((int)SpecialCategories.AllCategoriesButRealEstate).ToString(), Text = "All Categories except Real Estate" }); catList.Insert(1, new SelectListItem() { Value = "-1", Text = "--------------------------------" }); _CategoryList = catList.ToArray(); } return _CategoryList; } private static SelectListItem[] _CategoryList ; This seemed normal enough to me - I've been doing stuff like this forever caching smallish lists in memory to avoid an extra trip to the database. This list is used in various places throughout the application - for the list display and also when adding new items and setting up for notifications etc.. Watch that ModelBinder! However, it turns out that this code is clearly causing a problem. It appears that the model binder on the [HttpPost] method is actually updating the list that's bound to and changing the actual entry item in the list and setting its selected value. If you look at the code above I'm not setting the SelectListItem.Selected value anywhere - the only place this value can get set is through ModelBinding. Sure enough when stepping through the code I see that when an item is selected the actual model - model.CategoryList[x].Selected - reflects that. This is bad on several levels: First it's obviously affecting the application behavior - nobody wants to see their drop down list values jump all over the place randomly. But it's also a problem because the array is getting updated by multiple ASP.NET threads which likely would lead to odd crashes from time to time. Not good! In retrospect the modelbinding behavior makes perfect sense. The actual items and the Selected property is the ModelBinder's way of keeping track of one or more selected values. So while I assumed the list to be read-only, the ModelBinder is actually updating it on a post back producing the rather surprising results. Totally missed this during testing and is another one of those little - "Did you know?" moments. So, is there a way around this? Yes but it's maybe not quite obvious. I can't change the behavior of the ModelBinder, but I can certainly change the way that the list is generated. Rather than returning the cached list, I can return a brand new cloned list from the cached items like this:/// <summary> /// Returns a static category list that is cached /// </summary> /// <returns></returns> public static SelectListItem[] GetCachedCategoryList() { if (_CategoryList != null) { // Have to create new instances via projection // to avoid ModelBinding updates to affect this // globally return _CategoryList .Select(cat => new SelectListItem() { Value = cat.Value, Text = cat.Text }) .ToArray(); } …}  The key is that newly created instances of SelectListItems are returned not just filtered instances of the original list. The key here is 'new instances' so that the ModelBinding updates do not update the actual static instance. The code above uses LINQ and a projection into new SelectListItem instances to create this array of fresh instances. And this code works correctly - no more cross-talk between users. Unfortunately this code is also less efficient - it has to reselect the items and uses extra memory for the new array. Knowing what I know now I probably would have not cached the list and just take the hit to read from the database. If there is even a possibility of thread clashes I'm very wary of creating code like this. But since the method already exists and handles this load in one place this fix was easy enough to put in. Live and learn. It's little things like this that can cause some interesting head scratchers sometimes…© Rick Strahl, West Wind Technologies, 2005-2012Posted in MVC  ASP.NET  .NET   Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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• Adding DTrace Probes to PHP Extensions

  - by cj

  The powerful DTrace tracing facility has some PHP-specific probes that can be enabled with --enable-dtrace. DTrace for Linux is being created by Oracle and is currently in tech preview. Currently it doesn't support userspace tracing so, in the meantime, Systemtap can be used to monitor the probes implemented in PHP. This was recently outlined in David Soria Parra's post Probing PHP with Systemtap on Linux. My post shows how DTrace probes can be added to PHP extensions and traced on Linux. I was using Oracle Linux 6.3. Not all Linux kernels are built with Systemtap, since this can impact stability. Check whether your running kernel (or others installed) have Systemtap enabled, and reboot with such a kernel: # grep CONFIG_UTRACE /boot/config-`uname -r` # grep CONFIG_UTRACE /boot/config-* When you install Systemtap itself, the package systemtap-sdt-devel is needed since it provides the sdt.h header file: # yum install systemtap-sdt-devel You can now install and build PHP as shown in David's article. Basically the build is with: $ cd ~/php-src $ ./configure --disable-all --enable-dtrace $ make (For me, running 'make' a second time failed with an error. The workaround is to do 'git checkout Zend/zend_dtrace.d' and then rerun 'make'. See PHP Bug 63704) David's article shows how to trace the probes already implemented in PHP. You can also use Systemtap to trace things like userspace PHP function calls. For example, create test.php: <?php $c = oci_connect('hr', 'welcome', 'localhost/orcl'); $s = oci_parse($c, "select dbms_xmlgen.getxml('select * from dual') xml from dual"); $r = oci_execute($s); $row = oci_fetch_array($s, OCI_NUM); $x = $row[0]->load(); $row[0]->free(); echo $x; ?> The normal output of this file is the XML form of Oracle's DUAL table: $ ./sapi/cli/php ~/test.php <?xml version="1.0"?> <ROWSET> <ROW> <DUMMY>X</DUMMY> </ROW> </ROWSET> To trace the PHP function calls, create the tracing file functrace.stp: probe process("sapi/cli/php").function("zif_*") { printf("Started function %s\n", probefunc()); } probe process("sapi/cli/php").function("zif_*").return { printf("Ended function %s\n", probefunc()); } This makes use of the way PHP userspace functions (not builtins) like oci_connect() map to C functions with a "zif_" prefix. Login as root, and run System tap on the PHP script: # cd ~cjones/php-src # stap -c 'sapi/cli/php ~cjones/test.php' ~cjones/functrace.stp Started function zif_oci_connect Ended function zif_oci_connect Started function zif_oci_parse Ended function zif_oci_parse Started function zif_oci_execute Ended function zif_oci_execute Started function zif_oci_fetch_array Ended function zif_oci_fetch_array Started function zif_oci_lob_load <?xml version="1.0"?> <ROWSET> <ROW> <DUMMY>X</DUMMY> </ROW> </ROWSET> Ended function zif_oci_lob_load Started function zif_oci_free_descriptor Ended function zif_oci_free_descriptor Each call and return is logged. The Systemtap scripting language allows complex scripts to be built. There are many examples on the web. To augment this generic capability and the PHP probes in PHP, other extensions can have probes too. Below are the steps I used to add probes to OCI8: I created a provider file ext/oci8/oci8_dtrace.d, enabling three probes. The first one will accept a parameter that runtime tracing can later display: provider php { probe oci8__connect(char *username); probe oci8__nls_start(); probe oci8__nls_done(); }; I updated ext/oci8/config.m4 with the PHP_INIT_DTRACE macro. The patch is at the end of config.m4. The macro takes the provider prototype file, a name of the header file that 'dtrace' will generate, and a list of sources files with probes. When --enable-dtrace is used during PHP configuration, then the outer $PHP_DTRACE check is true and my new probes will be enabled. I've chosen to define an OCI8 specific macro, HAVE_OCI8_DTRACE, which can be used in the OCI8 source code: diff --git a/ext/oci8/config.m4 b/ext/oci8/config.m4 index 34ae76c..f3e583d 100644 --- a/ext/oci8/config.m4 +++ b/ext/oci8/config.m4 @@ -341,4 +341,17 @@ if test "$PHP_OCI8" != "no"; then PHP_SUBST_OLD(OCI8_ORACLE_VERSION) fi + + if test "$PHP_DTRACE" = "yes"; then + AC_CHECK_HEADERS([sys/sdt.h], [ + PHP_INIT_DTRACE([ext/oci8/oci8_dtrace.d], + [ext/oci8/oci8_dtrace_gen.h],[ext/oci8/oci8.c]) + AC_DEFINE(HAVE_OCI8_DTRACE,1, + [Whether to enable DTrace support for OCI8 ]) + ], [ + AC_MSG_ERROR( + [Cannot find sys/sdt.h which is required for DTrace support]) + ]) + fi + fi In ext/oci8/oci8.c, I added the probes at, for this example, semi-arbitrary places: diff --git a/ext/oci8/oci8.c b/ext/oci8/oci8.c index e2241cf..ffa0168 100644 --- a/ext/oci8/oci8.c +++ b/ext/oci8/oci8.c @@ -1811,6 +1811,12 @@ php_oci_connection *php_oci_do_connect_ex(char *username, int username_len, char } } +#ifdef HAVE_OCI8_DTRACE + if (DTRACE_OCI8_CONNECT_ENABLED()) { + DTRACE_OCI8_CONNECT(username); + } +#endif + /* Initialize global handles if they weren't initialized before */ if (OCI_G(env) == NULL) { php_oci_init_global_handles(TSRMLS_C); @@ -1870,11 +1876,22 @@ php_oci_connection *php_oci_do_connect_ex(char *username, int username_len, char size_t rsize = 0; sword result; +#ifdef HAVE_OCI8_DTRACE + if (DTRACE_OCI8_NLS_START_ENABLED()) { + DTRACE_OCI8_NLS_START(); + } +#endif PHP_OCI_CALL_RETURN(result, OCINlsEnvironmentVariableGet, (&charsetid_nls_lang, 0, OCI_NLS_CHARSET_ID, 0, &rsize)); if (result != OCI_SUCCESS) { charsetid_nls_lang = 0; } smart_str_append_unsigned_ex(&hashed_details, charsetid_nls_lang, 0); + +#ifdef HAVE_OCI8_DTRACE + if (DTRACE_OCI8_NLS_DONE_ENABLED()) { + DTRACE_OCI8_NLS_DONE(); + } +#endif } timestamp = time(NULL); The oci_connect(), oci_pconnect() and oci_new_connect() calls all use php_oci_do_connect_ex() internally. The first probe simply records that the PHP application made a connection call. I already showed a way to do this without needing a probe, but adding a specific probe lets me record the username. The other two probes can be used to time how long the globalization initialization takes. The relationships between the oci8_dtrace.d names like oci8__connect, the probe guards like DTRACE_OCI8_CONNECT_ENABLED() and probe names like DTRACE_OCI8_CONNECT() are obvious after seeing the pattern of all three probes. I included the new header that will be automatically created by the dtrace tool when PHP is built. I did this in ext/oci8/php_oci8_int.h: diff --git a/ext/oci8/php_oci8_int.h b/ext/oci8/php_oci8_int.h index b0d6516..c81fc5a 100644 --- a/ext/oci8/php_oci8_int.h +++ b/ext/oci8/php_oci8_int.h @@ -44,6 +44,10 @@ # endif # endif /* osf alpha */ +#ifdef HAVE_OCI8_DTRACE +#include "oci8_dtrace_gen.h" +#endif + #if defined(min) #undef min #endif Now PHP can be rebuilt: $ cd ~/php-src $ rm configure && ./buildconf --force $ ./configure --disable-all --enable-dtrace \ --with-oci8=instantclient,/home/cjones/instantclient $ make If 'make' fails, do the 'git checkout Zend/zend_dtrace.d' trick I mentioned. The new probes can be seen by logging in as root and running: # stap -l 'process.provider("php").mark("oci8*")' -c 'sapi/cli/php -i' process("sapi/cli/php").provider("php").mark("oci8__connect") process("sapi/cli/php").provider("php").mark("oci8__nls_done") process("sapi/cli/php").provider("php").mark("oci8__nls_start") To test them out, create a new trace file, oci.stp: global numconnects; global start; global numcharlookups = 0; global tottime = 0; probe process.provider("php").mark("oci8-connect") { printf("Connected as %s\n", user_string($arg1)); numconnects += 1; } probe process.provider("php").mark("oci8-nls_start") { start = gettimeofday_us(); numcharlookups++; } probe process.provider("php").mark("oci8-nls_done") { tottime += gettimeofday_us() - start; } probe end { printf("Connects: %d, Charset lookups: %ld\n", numconnects, numcharlookups); printf("Total NLS charset initalization time: %ld usecs/connect\n", (numcharlookups 0 ? tottime/numcharlookups : 0)); } This calculates the average time that the NLS character set lookup takes. It also prints out the username of each connection, as an example of using parameters. Login as root and run Systemtap over the PHP script: # cd ~cjones/php-src # stap -c 'sapi/cli/php ~cjones/test.php' ~cjones/oci.stp Connected as cj <?xml version="1.0"?> <ROWSET> <ROW> <DUMMY>X</DUMMY> </ROW> </ROWSET> Connects: 1, Charset lookups: 1 Total NLS charset initalization time: 164 usecs/connect This shows the time penalty of making OCI8 look up the default character set. This time would be zero if a character set had been passed as the fourth argument to oci_connect() in test.php.

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• Reporting Services - It's a Wrap!

  - by smisner

  If you have any experience at all with Reporting Services, you have probably developed a report using the matrix data region. It's handy when you want to generate columns dynamically based on data. If users view a matrix report online, they can scroll horizontally to view all columns and all is well. But if they want to print the report, the experience is completely different and you'll have to decide how you want to handle dynamic columns. By default, when a user prints a matrix report for which the number of columns exceeds the width of the page, Reporting Services determines how many columns can fit on the page and renders one or more separate pages for the additional columns. In this post, I'll explain two techniques for managing dynamic columns. First, I'll show how to use the RepeatRowHeaders property to make it easier to read a report when columns span multiple pages, and then I'll show you how to "wrap" columns so that you can avoid the horizontal page break. Included with this post are the sample RDLs for download. First, let's look at the default behavior of a matrix. A matrix that has too many columns for one printed page (or output to page-based renderer like PDF or Word) will be rendered such that the first page with the row group headers and the inital set of columns, as shown in Figure 1. The second page continues by rendering the next set of columns that can fit on the page, as shown in Figure 2.This pattern continues until all columns are rendered. The problem with the default behavior is that you've lost the context of employee and sales order - the row headers - on the second page. That makes it hard for users to read this report because the layout requires them to flip back and forth between the current page and the first page of the report. You can fix this behavior by finding the RepeatRowHeaders of the tablix report item and changing its value to True. The second (and subsequent pages) of the matrix now look like the image shown in Figure 3. The problem with this approach is that the number of printed pages to flip through is unpredictable when you have a large number of potential columns. What if you want to include all columns on the same page? You can take advantage of the repeating behavior of a tablix and get repeating columns by embedding one tablix inside of another. For this example, I'm using SQL Server 2008 R2 Reporting Services. You can get similar results with SQL Server 2008. (In fact, you could probably do something similar in SQL Server 2005, but I haven't tested it. The steps would be slightly different because you would be working with the old-style matrix as compared to the new-style tablix discussed in this post.) I created a dataset that queries AdventureWorksDW2008 tables: SELECT TOP (100) e.LastName + ', ' + e.FirstName AS EmployeeName, d.FullDateAlternateKey, f.SalesOrderNumber, p.EnglishProductName, sum(SalesAmount) as SalesAmount FROM FactResellerSales AS f INNER JOIN DimProduct AS p ON p.ProductKey = f.ProductKey INNER JOIN DimDate AS d ON d.DateKey = f.OrderDateKey INNER JOIN DimEmployee AS e ON e.EmployeeKey = f.EmployeeKey GROUP BY p.EnglishProductName, d.FullDateAlternateKey, e.LastName + ', ' + e.FirstName, f.SalesOrderNumber ORDER BY EmployeeName, f.SalesOrderNumber, p.EnglishProductName To start the report: Add a matrix to the report body and drag Employee Name to the row header, which also creates a group. Next drag SalesOrderNumber below Employee Name in the Row Groups panel, which creates a second group and a second column in the row header section of the matrix, as shown in Figure 4. Now for some trickiness. Add another column to the row headers. This new column will be associated with the existing EmployeeName group rather than causing BIDS to create a new group. To do this, right-click on the EmployeeName textbox in the bottom row, point to Insert Column, and then click Inside Group-Right. Then add the SalesOrderNumber field to this new column. By doing this, you're creating a report that repeats a set of columns for each EmployeeName/SalesOrderNumber combination that appears in the data. Next, modify the first row group's expression to group on both EmployeeName and SalesOrderNumber. In the Row Groups section, right-click EmployeeName, click Group Properties, click the Add button, and select [SalesOrderNumber]. Now you need to configure the columns to repeat. Rather than use the Columns group of the matrix like you might expect, you're going to use the textbox that belongs to the second group of the tablix as a location for embedding other report items. First, clear out the text that's currently in the third column - SalesOrderNumber - because it's already added as a separate textbox in this report design. Then drag and drop a matrix into that textbox, as shown in Figure 5. Again, you need to do some tricks here to get the appearance and behavior right. We don't really want repeating rows in the embedded matrix, so follow these steps: Click on the Rows label which then displays RowGroup in the Row Groups pane below the report body. Right-click on RowGroup,click Delete Group, and select the option to delete associated rows and columns. As a result, you get a modified matrix which has only a ColumnGroup in it, with a row above a double-dashed line for the column group and a row below the line for the aggregated data. Let's continue: Drag EnglishProductName to the data textbox (below the line). Add a second data row by right-clicking EnglishProductName, pointing to Insert Row, and clicking Below. Add the SalesAmount field to the new data textbox. Now eliminate the column group row without eliminating the group. To do this, right-click the row above the double-dashed line, click Delete Rows, and then select Delete Rows Only in the message box. Now you're ready for the fit and finish phase: Resize the column containing the embedded matrix so that it fits completely. Also, the final column in the matrix is for the column group. You can't delete this column, but you can make it as small as possible. Just click on the matrix to display the row and column handles, and then drag the right edge of the rightmost column to the left to make the column virtually disappear. Next, configure the groups so that the columns of the embedded matrix will wrap. In the Column Groups pane, right-click ColumnGroup1 and click on the expression button (labeled fx) to the right of Group On [EnglishProductName]. Replace the expression with the following: =RowNumber("SalesOrderNumber" ). We use SalesOrderNumber here because that is the name of the group that "contains" the embedded matrix. The next step is to configure the number of columns to display before wrapping. Click any cell in the matrix that is not inside the embedded matrix, and then double-click the second group in the Row Groups pane - SalesOrderNumber. Change the group expression to the following expression: =Ceiling(RowNumber("EmployeeName")/3) The last step is to apply formatting. In my example, I set the SalesAmount textbox's Format property to C2 and also right-aligned the text in both the EnglishProductName and the SalesAmount textboxes. And voila - Figure 6 shows a matrix report with wrapping columns. Share this post: email it! | bookmark it! | digg it! | reddit! | kick it! | live it!

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• Soapi.CS : A fully relational fluent .NET Stack Exchange API client library

  - by Sky Sanders

  Soapi.CS for .Net / Silverlight / Windows Phone 7 / Mono as easy as breathing...: var context = new ApiContext(apiKey).Initialize(false); Question thisPost = context.Official .StackApps .Questions.ById(386) .WithComments(true) .First(); Console.WriteLine(thisPost.Title); thisPost .Owner .Questions .PageSize(5) .Sort(PostSort.Votes) .ToList() .ForEach(q=> { Console.WriteLine("\t" + q.Score + "\t" + q.Title); q.Timeline.ToList().ForEach(t=> Console.WriteLine("\t\t" + t.TimelineType + "\t" + t.Owner.DisplayName)); Console.WriteLine(); }); // if you can think it, you can get it. Output Soapi.CS : A fully relational fluent .NET Stack Exchange API client library 21 Soapi.CS : A fully relational fluent .NET Stack Exchange API client library Revision code poet Revision code poet Votes code poet Votes code poet Revision code poet Revision code poet Revision code poet Votes code poet Votes code poet Votes code poet Revision code poet Revision code poet Revision code poet Revision code poet Revision code poet Revision code poet Revision code poet Revision code poet Revision code poet Revision code poet Votes code poet Comment code poet Revision code poet Votes code poet Revision code poet Revision code poet Revision code poet Answer code poet Revision code poet Revision code poet 14 SOAPI-WATCH: A realtime service that notifies subscribers via twitter when the API changes in any way. Votes code poet Revision code poet Votes code poet Comment code poet Comment code poet Comment code poet Votes lfoust Votes code poet Comment code poet Comment code poet Comment code poet Comment code poet Revision code poet Comment lfoust Votes code poet Revision code poet Votes code poet Votes lfoust Votes code poet Revision code poet Comment Dave DeLong Revision code poet Revision code poet Votes code poet Comment lfoust Comment Dave DeLong Comment lfoust Comment lfoust Comment Dave DeLong Revision code poet 11 SOAPI-EXPLORE: Self-updating single page JavaSript API test harness Votes code poet Votes code poet Votes code poet Votes code poet Votes code poet Comment code poet Revision code poet Votes code poet Revision code poet Revision code poet Revision code poet Comment code poet Revision code poet Votes code poet Comment code poet Question code poet Votes code poet 11 Soapi.JS V1.0: fluent JavaScript wrapper for the StackOverflow API Comment George Edison Comment George Edison Comment George Edison Comment George Edison Comment George Edison Comment George Edison Answer George Edison Votes code poet Votes code poet Votes code poet Votes code poet Revision code poet Revision code poet Answer code poet Comment code poet Revision code poet Comment code poet Comment code poet Comment code poet Revision code poet Revision code poet Votes code poet Votes code poet Votes code poet Votes code poet Comment code poet Comment code poet Comment code poet Comment code poet Comment code poet 9 SOAPI-DIFF: Your app broke? Check SOAPI-DIFF to find out what changed in the API Votes code poet Revision code poet Comment Dennis Williamson Answer Dennis Williamson Votes code poet Votes Dennis Williamson Comment code poet Question code poet Votes code poet About A robust, fully relational, easy to use, strongly typed, end-to-end StackOverflow API Client Library. Out of the box, Soapi provides you with a robust client library that abstracts away most all of the messy details of consuming the API and lets you concentrate on implementing your ideas. A few features include: A fully relational model of the API data set exposed via a fully 'dot navigable' IEnumerable (LINQ) implementation. Simply tell Soapi what you want and it will get it for you. e.g. "On my first question, from the author of the first comment, get the first page of comments by that person on any post" my.Questions.First().Comments.First().Owner.Comments.ToList(); (yes this is a real expression that returns the data as expressed!) Full coverage of the API, all routes and all parameters with an intuitive syntax. Strongly typed Domain Data Objects for all API data structures. Eager and Lazy Loading of 'stub' objects. Eager\Lazy loading may be disabled. When finer grained control of requests is desired, the core RouteMap objects may be leveraged to request data from any of the API paths using all available parameters as documented on the help pages. A rich Asynchronous implementation. A configurable request cache to reduce unnecessary network traffic and to simplify your usage logic. There is no need to go out of your way to be frugal. You may set a distinct cache duration for any particular route. A configurable request throttle to ensure compliance with the api terms of usage and to simplify your code in that you do not have to worry about and respond to 50X errors. The RequestCache and Throttled Queue are thread-safe, so can make as many requests as you like from as many threads as you like as fast as you like and not worry about abusing the api or having to write reams of management/compensation code. Configurable retry threshold that will, by default, make up to 3 attempts to retrieve a request before failing. Every request made by Soapi is properly formed and directed so most any http error will be the result of a timeout or other network infrastructure. A retry buffer provides a level of fault tolerance that you can rely on. An almost identical javascript library, Soapi.JS, and it's full figured big brother, Soapi.JS2, that will enable you to leverage your server cycles and bandwidth for only those tasks that require it and offload things like status updates to the client's browser. License Licensed GPL Version 2 license. Why is Soapi.CS GPL? Can I get an LGPL license for Soapi.CS? (hint: probably) Platforms .NET 3.5 .NET 4.0 Silverlight 3 Silverlight 4 Windows Phone 7 Mono Download Source code lives @ http://soapics.codeplex.com. Binary releases are forthcoming. codeplex is acting up again. get the source and binaries @ http://bitbucket.org/bitpusher/soapi.cs/downloads The source is C# 3.5. and includes projects and solutions for the following IDEs Visual Studio 2008 Visual Studio 2010 ModoDevelop 2.4 Documentation Full documentation is available at http://soapi.info/help/cs/index.aspx Sample Code / Usage Examples Sample code and usage examples will be added as answers to this question. Full API Coverage all API routes are covered Full Parameter Parity If the API exposes it, Soapi giftwraps it for you. Building a simple app with Soapi.CS - a simple app that gathers all traces of a user in the whole stackiverse. Fluent Configuration - Setting up a Soapi.ApiContext could not be easier Bulk Data Import - A tiny app that quickly loads a SQLite data file with all users in the stackiverse. Paged Results - Soapi.CS transparently handles multi-page operations. Asynchronous Requests - Soapi.CS provides a rich asynchronous model that is especially useful when writing api apps in Silverlight or Windows Phone 7. Caching and Throttling - how and why Apps that use Soapi.CS Soapi.FindUser - .net utility for locating a user anywhere in the stackiverse Soapi.Explore - The entire API at your command Soapi.LastSeen - List users by last access time Add your app/site here - I know you are out there ;-) if you are not comfortable editing this post, simply add a comment and I will add it. The CS/SL/WP7/MONO libraries all compile the same code and with the exception of environmental considerations of Silverlight, the code samples are valid for all libraries. You may also find guidance in the test suites. More information on the SOAPI eco-system. Contact This library is currently the effort of me, Sky Sanders (code poet) and can be reached at gmail - sky.sanders Any who are interested in improving this library are welcome. Support Soapi You can help support this project by voting for Soapi's Open Source Ad post For more information about the origins of Soapi.CS and the rest of the Soapi eco-system see What is Soapi and why should I care?

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• Replacing jQuery.live() with jQuery.on()

  - by Rick Strahl

  jQuery 1.9 and 1.10 have introduced a host of changes, but for the most part these changes are mostly transparent to existing application usage of jQuery. After spending some time last week with a few of my projects and going through them with a specific eye for jQuery failures I found that for the most part there wasn't a big issue. The vast majority of code continues to run just fine with either 1.9 or 1.10 (which are supposed to be in sync but with 1.10 removing support for legacy Internet Explorer pre-9.0 versions). However, one particular change in the new versions has caused me quite a bit of update trouble, is the removal of the jQuery.live() function. This is my own fault I suppose - .live() has been deprecated for a while, but with 1.9 and later it was finally removed altogether from jQuery. In the past I had quite a bit of jQuery code that used .live() and it's one of the things that's holding back my upgrade process, although I'm slowly cleaning up my code and switching to the .on() function as the replacement. jQuery.live() jQuery.live() was introduced a long time ago to simplify handling events on matched elements that exist currently on the document and those that are are added in the future and also match the selector. jQuery uses event bubbling, special event binding, plus some magic using meta data attached to a parent level element to check and see if the original target event element matches the selected selected elements (for more info see Elijah Manor's comment below). An Example Assume a list of items like the following in HTML for example and further assume that the items in this list can be appended to at a later point. In this app there's a smallish initial list that loads to start, and as the user scrolls towards the end of the initial small list more items are loaded dynamically and added to the list.<div id="PostItemContainer" class="scrollbox"> <div class="postitem" data-id="4z6qhomm"> <div class="post-icon"></div> <div class="postitemheader"><a href="show/4z6qhomm" target="Content">1999 Buick Century For Sale!</a></div> <div class="postitemprice rightalign">$ 3,500 O.B.O.</div> <div class="smalltext leftalign">Jun. 07 @ 1:06am</div> <div class="post-byline">- Vehicles - Automobiles</div> </div> <div class="postitem" data-id="2jtvuu17"> <div class="postitemheader"><a href="show/2jtvuu17" target="Content">Toyota VAN 1987</a></div> <div class="postitemprice rightalign">$950</div> <div class="smalltext leftalign">Jun. 07 @ 12:29am</div> <div class="post-byline">- Vehicles - Automobiles</div> </div> … </div> With the jQuery.live() function you could easily select elements and hook up a click handler like this:$(".postitem").live("click", function() {...}); Simple and perfectly readable. The behavior of the .live handler generally was the same as the corresponding simple event handlers like .click(), except that you have to explicitly name the event instead of using one of the methods. Re-writing with jQuery.on() With .live() removed in 1.9 and later we have to re-write .live() code above with an alternative. The jQuery documentation points you at the .on() or .delegate() functions to update your code. jQuery.on() is a more generic event handler function, and it's what jQuery uses internally to map the high level event functions like .click(),.change() etc. that jQuery exposes. Using jQuery.on() however is not a one to one replacement of the .live() function. While .on() can handle events directly and use the same syntax as .live() did, you'll find if you simply switch out .live() with .on() that events on not-yet existing elements will not fire. IOW, the key feature of .live() is not working. You can use .on() to get the desired effect however, but you have to change the syntax to explicitly handle the event you're interested in on the container and then provide a filter selector to specify which elements you are actually interested in for handling the event for. Sounds more complicated than it is and it's easier to see with an example. For the list above hooking .postitem clicks, using jQuery.on() looks like this:$("#PostItemContainer").on("click", ".postitem", function() {...}); You specify a container that can handle the .click event and then provide a filter selector to find the child elements that trigger the  the actual event. So here #PostItemContainer contains many .postitems, whose click events I want to handle. Any container will do including document, but I tend to use the container closest to the elements I actually want to handle the events on to minimize the event bubbling that occurs to capture the event. With this code I get the same behavior as with .live() and now as new .postitem elements are added the click events are always available. Sweet. Here's the full event signature for the .on() function: .on( events [, selector ] [, data ], handler(eventObject) ) Note that the selector is optional - if you omit it you essentially create a simple event handler that handles the event directly on the selected object. The filter/child selector required if you want life-like - uh, .live() like behavior to happen. While it's a bit more verbose than what .live() did, .on() provides the same functionality by being more explicit on what your parent container for trapping events is. .on() is good Practice even for ordinary static Element Lists As a side note, it's a good practice to use jQuery.on() or jQuery.delegate() for events in most cases anyway, using this 'container event trapping' syntax. That's because rather than requiring lots of event handlers on each of the child elements (.postitem in the sample above), there's just one event handler on the container, and only when clicked does jQuery drill down to find the matching filter element and tries to match it to the originating element. In the early days of jQuery I used manually build handlers that did this and manually drilled from the event object into the originalTarget to determine if it's a matching element. With later versions of jQuery the various event functions in jQuery essentially provide this functionality out of the box with functions like .on() and .delegate(). All of this is nothing new, but I thought I'd write this up because I have on a few occasions forgotten what exactly was needed to replace the many .live() function calls that litter my code - especially older code. This will be a nice reminder next time I have a memory blank on this topic. And maybe along the way I've helped one or two of you as well to clean up your .live() code…© Rick Strahl, West Wind Technologies, 2005-2013Posted in jQuery   Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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• I have Oracle SQL Developer Installed, Now What?

  - by thatjeffsmith

  If you’re here because you downloaded a copy of Oracle SQL Developer and now you need help connecting to a database, then you’re in the right place. I’ll show you what you need to get up and going so you can finish your homework, teach yourself Oracle database, or get ready for that job interview. You’ll need about 30 minutes to set everything up…and about 5 years to become proficient with Oracle Oracle Database come with SQL Developer but SQL Developer doesn’t include a database If you install Oracle database, it includes a copy of SQL Developer. If you’re running that copy of SQL Developer, please take a second to upgrade now, as it is WAY out of date. But I’m here to talk to the folks that have downloaded SQL Developer and want to know what to do next. You’ve got it running. You see this ‘Connection’ dialog, and… Where am I connecting to, and who as? You NEED a database Installing SQL Developer does not give you a database. So you’re going to need to install Oracle and create a database, or connect to a database that is already up and running somewhere. Basically you need to know the following: where is this database, what’s it called, and what port is the listener running on? The Default Connection properties in SQL Developer These default settings CAN work, but ONLY if you have installed Oracle Database Express Edition (XE). Localhost is a network alias for 127.0.0.1 which is an IP address that maps to the ‘local’ machine, or the machine you are reading this blog post on. The listener is a service that runs on the server and handles connections for the databases on that machine. You can run a database without a listener and you can run a listener without a database, but you can’t connect to a database on a different server unless both that database and listener are up and running. Each listener ‘listens’ on one or more ports, you need to know the port number for each connection. The default port is 1521, but 1522 is often pretty common. I know all of this sounds very complicated Oracle is a very sophisticated piece of software. It’s not analogous to downloading a mobile phone app and and using it 10 seconds later. It’s not like installing Office/Access either – it requires services, environment setup, kernel tweaks, etc. However. Normally an administrator will setup and install Oracle, create the database, and configure the listener for everyone else to use. They’ll often also setup the connection details for everyone via a ‘TNSNAMES.ORA’ file. This file contains a list of database connection details for folks to browse – kind of like an Oracle database phoneboook. If someone has given you a TNSNAMES.ORA file, or setup your machine to have access to a TNSNAMES file, then you can just switch to the ‘TNS’ connection type, and use the dropdown to select the database you want to connect to. Then you don’t have to worry about the server names, database names, and the port numbers. ORCL – that sounds promising! ORCL is the default SID when creating a new database with the Database Creation Assistant (DBCA). It’s just me, and I need help! No administrator, no database, no nothing. What do you do? You have a few options: Buy a copy of Oracle and download, install, and create a database Download and install XE (FREE!) Download, import, and run our Developer Days Hands-on-Lab (FREE!) If you’re a student (or anyone else) with little to no experience with Oracle, then I recommend the third option. Oracle Technology Network Developer Day: Hands-on Database Application Development Lab The OTN lab runs on a A Virtual Box image which contains: 11gR2 Enterprise Edition copy of Oracle a database and listener running for you to connect to lots of demo data for you to play with SQL Developer installed and ready to connect Some browser based labs you can step through to learn Oracle You download the image, you download and install Virtual Box (also FREE!), then you IMPORT the image you previously downloaded. You then ‘Start’ the image. It will boot a copy of Oracle Enterprise Linux (OEL), start your database, and all that jazz. You can then start up and run SQL Developer inside the image OR you can connect to the database running on the image using the copy of SQL Developer you installed on your host machine. Setup Port Forwarding to Make It Easy to Connect From Your Host When you start the image, it will be assigned an IP address. Depending on what network adapter you select in the image preferences, you may get something that can get out to the internet from your image, something your host machine can see and connect to, or something that kind of just lives out there in a vacuum. You want to avoid the ‘vacuum’ option – unless you’re OK with running SQL Developer inside the Linux image. Open the Virtual Box image properties and go to the Networking options. We’re going to setup port forwarding. This will tell your machine that anything that happens on port 1521 (the default Oracle Listener port), should just go to the image’s port 1521. So I can connect to ‘localhost’ and it will magically get transferred to the image that is running. Oracle Virtual Box Port Forwarding 1521 listener database Now You Just Need a Username and Password The default passwords on this image are all ‘oracle’ – so you can connect as SYS, HR, or whatever – just use ‘oracle’ as the password. The Linux passowrds are all ‘oracle’ too, so you can login as ‘root’ or as ‘oracle’ in the Linux desktop. Connect! Connect as HR to your Oracle database running on the OTN Developer Days Virtual Box image If you’re connecting to someone else’s database, you need to ask the person that manages that environment to create for you an account. Don’t try to ‘guess’ or ‘figure out’ what the username and password is. Introduce yourself, explain your situation, and ask kindly for access. This is your first test – can you connect? I know it’s hard to get started with Oracle. There are however many things we offer to make this easier. You’ll need to do a bit of RTM first though. Once you know what’s required, you will be much more likely to succeed. Of course, if you need help, you know where to find me

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• Transparency and AlphaBlending

  - by TechTwaddle

  In this post we'll look at the AlphaBlend() api and how it can be used for semi-transparent blitting. AlphaBlend() takes a source device context and a destination device context (DC) and combines the bits in such a way that it gives a transparent effect. Follow the links for the msdn documentation. So lets take a image like, and AlphaBlend() it on our window. The code to do so is below, (under the WM_PAINT message of WndProc) HBITMAP hBitmap=NULL, hBitmapOld=NULL; HDC hMemDC=NULL; BLENDFUNCTION bf; hdc = BeginPaint(hWnd, &ps); hMemDC = CreateCompatibleDC(hdc); hBitmap = LoadBitmap(g_hInst, MAKEINTRESOURCE(IDB_BITMAP1)); hBitmapOld = SelectObject(hMemDC, hBitmap); bf.BlendOp = AC_SRC_OVER; bf.BlendFlags = 0; bf.SourceConstantAlpha = 80; //transparency value between 0-255 bf.AlphaFormat = 0;    AlphaBlend(hdc, 0, 25, 240, 100, hMemDC, 0, 0, 240, 100, bf); SelectObject(hMemDC, hBitmapOld); DeleteDC(hMemDC); DeleteObject(hBitmap); EndPaint(hWnd, &ps);   The code above creates a memory DC (hMemDC) using CreateCompatibleDC(), loads a bitmap onto the memory DC and AlphaBlends it on the device DC (hdc), with a transparency value of 80. The result is: Pretty simple till now. Now lets try to do something a little more exciting. Lets get two images involved, each overlapping the other, giving a better demonstration of transparency. I am also going to add a few buttons so that the user can increase or decrease the transparency by clicking on the buttons. Since this is the first time I played around with GDI apis, I ran into something that everybody runs into sometime or the other, flickering. When clicking the buttons the images would flicker a lot, I figured out why and used something called double buffering to avoid flickering. We will look at both my first implementation and the second implementation just to give the concept a little more depth and perspective. A few pre-conditions before I dive into the code: - hBitmap and hBitmap2 are handles to the two images obtained using LoadBitmap(), these variables are global and are initialized under WM_CREATE - The two buttons in the application are labeled Opaque++ (make more opaque, less transparent) and Opaque-- (make less opaque, more transparent) - DrawPics(HWND hWnd, int step=0); is the function called to draw the images on the screen. This is called from under WM_PAINT and also when the buttons are clicked. When Opaque++ is clicked the 'step' value passed to DrawPics() is +20 and when Opaque-- is clicked the 'step' value is -20. The default value of 'step' is 0 Now lets take a look at my first implementation: //this funciton causes flicker, cos it draws directly to screen several times void DrawPics(HWND hWnd, int step) {     HDC hdc=NULL, hMemDC=NULL;     BLENDFUNCTION bf;     static UINT32 transparency = 100;     //no point in drawing when transparency is 0 and user clicks Opaque--     if (transparency == 0 && step < 0)         return;     //no point in drawing when transparency is 240 (opaque) and user clicks Opaque++     if (transparency == 240 && step > 0)         return;         hdc = GetDC(hWnd);     if (!hdc)         return;     //create a memory DC     hMemDC = CreateCompatibleDC(hdc);     if (!hMemDC)     {         ReleaseDC(hWnd, hdc);         return;     }     //while increasing transparency, clear the contents of screen     if (step < 0)     {         RECT rect = {0, 0, 240, 200};         FillRect(hdc, &rect, (HBRUSH)GetStockObject(WHITE_BRUSH));     }     SelectObject(hMemDC, hBitmap2);     BitBlt(hdc, 0, 25, 240, 100, hMemDC, 0, 0, SRCCOPY);         SelectObject(hMemDC, hBitmap);     transparency += step;     if (transparency >= 240)         transparency = 240;     if (transparency <= 0)         transparency = 0;     bf.BlendOp = AC_SRC_OVER;     bf.BlendFlags = 0;     bf.SourceConstantAlpha = transparency;     bf.AlphaFormat = 0;            AlphaBlend(hdc, 0, 75, 240, 100, hMemDC, 0, 0, 240, 100, bf);     DeleteDC(hMemDC);     ReleaseDC(hWnd, hdc); }   In the code above, we first get the window DC using GetDC() and create a memory DC using CreateCompatibleDC(). Then we select hBitmap2 onto the memory DC and Blt it on the window DC (hdc). Next, we select the other image, hBitmap, onto memory DC and AlphaBlend() it over window DC. As I told you before, this implementation causes flickering because it draws directly on the screen (hdc) several times. The video below shows what happens when the buttons were clicked rapidly: Well, the video recording tool I use captures only 15 frames per second and so the flickering is not visible in the video. So you're gonna have to trust me on this, it flickers (; To solve this problem we make sure that the drawing to the screen happens only once and to do that we create an additional memory DC, hTempDC. We perform all our drawing on this memory DC and finally when it is ready we Blt hTempDC on hdc, and the images are displayed in one go. Here is the code for our new DrawPics() function: //no flicker void DrawPics(HWND hWnd, int step) {     HDC hdc=NULL, hMemDC=NULL, hTempDC=NULL;     BLENDFUNCTION bf;     HBITMAP hBitmapTemp=NULL, hBitmapOld=NULL;     static UINT32 transparency = 100;     //no point in drawing when transparency is 0 and user clicks Opaque--     if (transparency == 0 && step < 0)         return;     //no point in drawing when transparency is 240 (opaque) and user clicks Opaque++     if (transparency == 240 && step > 0)         return;         hdc = GetDC(hWnd);     if (!hdc)         return;     hMemDC = CreateCompatibleDC(hdc);     hTempDC = CreateCompatibleDC(hdc);     hBitmapTemp = CreateCompatibleBitmap(hdc, 240, 150);     hBitmapOld = (HBITMAP)SelectObject(hTempDC, hBitmapTemp);     if (!hMemDC)     {         ReleaseDC(hWnd, hdc);         return;     }     //while increasing transparency, clear the contents     if (step < 0)     {         RECT rect = {0, 0, 240, 150};         FillRect(hTempDC, &rect, (HBRUSH)GetStockObject(WHITE_BRUSH));     }     SelectObject(hMemDC, hBitmap2);     //Blt hBitmap2 directly to hTempDC     BitBlt(hTempDC, 0, 0, 240, 100, hMemDC, 0, 0, SRCCOPY);         SelectObject(hMemDC, hBitmap);     transparency += step;     if (transparency >= 240)         transparency = 240;     if (transparency <= 0)         transparency = 0;     bf.BlendOp = AC_SRC_OVER;     bf.BlendFlags = 0;     bf.SourceConstantAlpha = transparency;     bf.AlphaFormat = 0;            AlphaBlend(hTempDC, 0, 50, 240, 100, hMemDC, 0, 0, 240, 100, bf);     //now hTempDC is ready, blt it directly on hdc     BitBlt(hdc, 0, 25, 240, 150, hTempDC, 0, 0, SRCCOPY);     SelectObject(hTempDC, hBitmapOld);     DeleteObject(hBitmapTemp);     DeleteDC(hMemDC);     DeleteDC(hTempDC);     ReleaseDC(hWnd, hdc); }   This function is very similar to the first version, except for the use of hTempDC. Another point to note is the use of CreateCompatibleBitmap(). When a memory device context is created using CreateCompatibleDC(), the context is exactly one monochrome pixel high and one monochrome pixel wide. So in order for us to draw anything onto hTempDC, we first have to set a bitmap on it. We use CreateCompatibleBitmap() to create a bitmap of required dimension (240x150 above), and then select this bitmap onto hTempDC. Think of it as utilizing an extra canvas, drawing everything on the canvas and finally transferring the contents to the display in one scoop. And with this version the flickering is gone, video follows:   If you want the entire solutions source code then leave a message, I will share the code over SkyDrive.

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• Win a set of Infragistics Silverlight Controls with Data Visualization!

  - by mbcrump

  Infragistics recently released their new Silverlight Data Visualization Controls. I saw a couple of samples and had to take a look. I headed over to their website and downloaded the controls. I first noticed the hospital floor-plan demo shown on their site and started thinking of ways that I could use this in my own organization. I emailed them asking if I could give away the Silverlight Data Visualization controls on my site and they said, Yes! They also wanted to throw in the standard Silverlight Line of Business controls. (combined they are worth about $3000 US). I am very thankful they were willing to help the Silverlight community with this giveaway. So some quick rules below: ----------------------------------------------------------------------------------------------------------------------------------------------------------- Win a FREE developer’s license of Infragistics Silverlight Controls with Data Visualization ($3000 Value) Random winner will be announced on January 1st, 2011! To be entered into the contest do the following things: Subscribe to my feed. Leave a comment below with a valid email account (I WILL NOT share this info with anyone.) For extra entries simply: Retweet a link to this page using the following URL [ http://mcrump.me/iscfree ]. It does not matter what the tweet says, just as long as the URL is the same. Unlimited tweets, but please don’t go crazy! This URL will allow me to track the users that Tweet this page. Don’t forget to visit Infragistics because they made this possible. ---------------------------------------------------------------------------------------------------------------------------------------------------------- Before we get started with the Silverlight Controls, here is a couple of links to bookmark: The Silverlight Line of Business Control page is here. You can also check out the live demos here. The Data Visualization page is here. You can also check out the live demos here. Don’t worry about the Samples/Help Documentation. You can install all of that to your local HDD when you are installing it. I am going to walk you through the Silverlight Controls recently released by Infragistics. Begin by downloading the trial version and running the executable. If you downloaded the Complete bundle then you will have the following options to pick from. I like having help documentation and samples on my local HDD in case I do not have access to the internet and want to code. After it is installed, you may want to take a look at your Toolbox in Visual Studio 2010. Look for NetAdvantage 10.3 Silverlight and you will see that you now have access to all of these controls. At this point, to use the controls it’s as simple as drag/drop onto your Silverlight container. It will create the proper Namespaces for you. I wanted to highlight a few of the controls that I liked the most: Grid – After using the Infragistics grid you will wonder how you ever survived using the grid supplied by Microsoft standard controls.  This grid was designed to get your application up and running very fast. It’s simple to bind, it handles LARGE DataSets, easy to filter and allows endless possibilities of formatting data. The screenshot below is an example of the grid. For a real-time updating demo click here. SpellChecker- If your users are creating emails or performing any other function that requires Spell Checking then this control is great. Check out the screenshots below: In this first screen, I have a word that is not in the dictionary [DotNet]. The Spell Checker finds the word and allows the user to correct it. What is so great about Infragistics controls is that it only takes a few lines of code to have a full-featured Spell Checker in your application. TagCloud – This is a control that I haven’t seen anywhere else. It allows you to create keywords for popular search terms. This is very similar to TagCloud seen all over the internet.  Below is a screenshot that shows “Facebook” being a very popular item in the cloud. You can link these items to a hyperlink if you wanted. Importing/Exporting from Excel – I work with data a majority of the time. We all know the importance of Excel in our organizations, its used a lot. With Infragistics controls it make importing and exporting data from a Grid into Excel a snap. One of the things that I liked most about this control was the option to choose the Excel format (2003 or 2007). I haven’t seen this feature in other controls. Creating/Saving/Extracting/Uploading Zip Files – This is another control that I haven’t seen many others making. It allows you to basically manipulate a zip file in any way you like. You can even create a password on the zip file. Schedule – The Schedule that Infragistics provides resembles Outlook’s calendar. I think that it’s important for a user to see your app for the first time and immediately be able to start using because they are already familiar with the UI. The Schedule control accomplishes that in my opinion. I have just barely scratched the surface with the Infragistics Silverlight Line of Business controls. To check all of them then click here. A quick thing to note is that this giveaway also comes with the following Silverlight Data Visualization Controls. Below is a screenshot that list all of them:   I wanted to highlight 2 of the controls that I liked the most: xamBarcode– The xamBarcode supports the following Symbologies: Below is an example of the barcode generated by Infragistics controls. This is a high resolution barcode that you will not have to wonder if your scanner can read it. As long as you have ink in your printer your barcode will read it. I used a Symbol barcode reader to test this barcode. xamTreemap– I’ve never seen a way of displaying data like this before, but I like it. You can style this anyway that you like of course and it also comes with an Office 2010 Theme. Thanks to Infragistics for providing the controls to one lucky reader. I hope that you enjoyed this post and good luck to those that entered the contest.  Subscribe to my feed

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• Windows Azure VMs - New "Stopped" VM Options Provide Cost-effective Flexibility for On-Demand Workloads

  - by KeithMayer

  Originally posted on: http://geekswithblogs.net/KeithMayer/archive/2013/06/22/windows-azure-vms---new-stopped-vm-options-provide-cost-effective.aspxDidn’t make it to TechEd this year? Don’t worry!  This month, we’ll be releasing a new article series that highlights the Best of TechEd announcements and technical information for IT Pros.  Today’s article focuses on a new, much-heralded enhancement to Windows Azure Infrastructure Services to make it more cost-effective for spinning VMs up and down on-demand on the Windows Azure cloud platform. NEW! VMs that are shutdown from the Windows Azure Management Portal will no longer continue to accumulate compute charges while stopped! Previous to this enhancement being available, the Azure platform maintained fabric resource reservations for VMs, even in a shutdown state, to ensure consistent resource availability when starting those VMs in the future.  And, this meant that VMs had to be exported and completely deprovisioned when not in use to avoid compute charges. In this article, I'll provide more details on the scenarios that this enhancement best fits, and I'll also review the new options and considerations that we now have for performing safe shutdowns of Windows Azure VMs. Which scenarios does the new enhancement best fit? Being able to easily shutdown VMs from the Windows Azure Management Portal without continued compute charges is a great enhancement for certain cloud use cases, such as: On-demand dev/test/lab environments - Freely start and stop lab VMs so that they are only accumulating compute charges when being actively used.  "Bursting" load-balanced web applications - Provision a number of load-balanced VMs, but keep the minimum number of VMs running to support "normal" loads. Easily start-up the remaining VMs only when needed to support peak loads. Disaster Recovery - Start-up "cold" VMs when needed to recover from disaster scenarios. BUT ... there is a consideration to keep in mind when using the Windows Azure Management Portal to shutdown VMs: although performing a VM shutdown via the Windows Azure Management Portal causes that VM to no longer accumulate compute charges, it also deallocates the VM from fabric resources to which it was previously assigned.  These fabric resources include compute resources such as virtual CPU cores and memory, as well as network resources, such as IP addresses.  This means that when the VM is later started after being shutdown from the portal, the VM could be assigned a different IP address or placed on a different compute node within the fabric. In some cases, you may want to shutdown VMs using the old approach, where fabric resource assignments are maintained while the VM is in a shutdown state.  Specifically, you may wish to do this when temporarily shutting down or restarting a "7x24" VM as part of a maintenance activity.  Good news - you can still revert back to the old VM shutdown behavior when necessary by using the alternate VM shutdown approaches listed below.  Let's walk through each approach for performing a VM Shutdown action on Windows Azure so that we can understand the benefits and considerations of each... How many ways can I shutdown a VM? In Windows Azure Infrastructure Services, there's three general ways that can be used to safely shutdown VMs: Shutdown VM via Windows Azure Management Portal Shutdown Guest Operating System inside the VM Stop VM via Windows PowerShell using Windows Azure PowerShell Module Although each of these options performs a safe shutdown of the guest operation system and the VM itself, each option handles the VM shutdown end state differently. Shutdown VM via Windows Azure Management Portal When clicking the Shutdown button at the bottom of the Virtual Machines page in the Windows Azure Management Portal, the VM is safely shutdown and "deallocated" from fabric resources.  Shutdown button on Virtual Machines page in Windows Azure Management Portal  When the shutdown process completes, the VM will be shown on the Virtual Machines page with a "Stopped ( Deallocated )" status as shown in the figure below. Virtual Machine in a "Stopped (Deallocated)" Status "Deallocated" means that the VM configuration is no longer being actively associated with fabric resources, such as virtual CPUs, memory and networks. In this state, the VM will not continue to allocate compute charges, but since fabric resources are deallocated, the VM could receive a different internal IP address ( called "Dynamic IPs" or "DIPs" in Windows Azure ) the next time it is started.  TIP: If you are leveraging this shutdown option and consistency of DIPs is important to applications running inside your VMs, you should consider using virtual networks with your VMs.  Virtual networks permit you to assign a specific IP Address Space for use with VMs that are assigned to that virtual network.  As long as you start VMs in the same order in which they were originally provisioned, each VM should be reassigned the same DIP that it was previously using. What about consistency of External IP Addresses? Great question! External IP addresses ( called "Virtual IPs" or "VIPs" in Windows Azure ) are associated with the cloud service in which one or more Windows Azure VMs are running.  As long as at least 1 VM inside a cloud service remains in a "Running" state, the VIP assigned to a cloud service will be preserved.  If all VMs inside a cloud service are in a "Stopped ( Deallocated )" status, then the cloud service may receive a different VIP when VMs are next restarted. TIP: If consistency of VIPs is important for the cloud services in which you are running VMs, consider keeping one VM inside each cloud service in the alternate VM shutdown state listed below to preserve the VIP associated with the cloud service. Shutdown Guest Operating System inside the VM When performing a Guest OS shutdown or restart ( ie., a shutdown or restart operation initiated from the Guest OS running inside the VM ), the VM configuration will not be deallocated from fabric resources. In the figure below, the VM has been shutdown from within the Guest OS and is shown with a "Stopped" VM status rather than the "Stopped ( Deallocated )" VM status that was shown in the previous figure. Note that it may require a few minutes for the Windows Azure Management Portal to reflect that the VM is in a "Stopped" state in this scenario, because we are performing an OS shutdown inside the VM rather than through an Azure management endpoint. Virtual Machine in a "Stopped" Status VMs shown in a "Stopped" status will continue to accumulate compute charges, because fabric resources are still being reserved for these VMs.  However, this also means that DIPs and VIPs are preserved for VMs in this state, so you don't have to worry about VMs and cloud services getting different IP addresses when they are started in the future. Stop VM via Windows PowerShell In the latest version of the Windows Azure PowerShell Module, a new -StayProvisioned parameter has been added to the Stop-AzureVM cmdlet. This new parameter provides the flexibility to choose the VM configuration end result when stopping VMs using PowerShell: When running the Stop-AzureVM cmdlet without the -StayProvisioned parameter specified, the VM will be safely stopped and deallocated; that is, the VM will be left in a "Stopped ( Deallocated )" status just like the end result when a VM Shutdown operation is performed via the Windows Azure Management Portal.  When running the Stop-AzureVM cmdlet with the -StayProvisioned parameter specified, the VM will be safely stopped but fabric resource reservations will be preserved; that is the VM will be left in a "Stopped" status just like the end result when performing a Guest OS shutdown operation. So, with PowerShell, you can choose how Windows Azure should handle VM configuration and fabric resource reservations when stopping VMs on a case-by-case basis. TIP: It's important to note that the -StayProvisioned parameter is only available in the latest version of the Windows Azure PowerShell Module.  So, if you've previously downloaded this module, be sure to download and install the latest version to get this new functionality. Want to Learn More about Windows Azure Infrastructure Services? To learn more about Windows Azure Infrastructure Services, be sure to check-out these additional FREE resources: Become our next "Early Expert"! Complete the Early Experts "Cloud Quest" and build a multi-VM lab network in the cloud for FREE!  Build some cool scenarios! Check out our list of over 20+ Step-by-Step Lab Guides based on key scenarios that IT Pros are implementing on Windows Azure Infrastructure Services TODAY!  Looking forward to seeing you in the Cloud! - Keith Build Your Lab! Download Windows Server 2012 Don’t Have a Lab? Build Your Lab in the Cloud with Windows Azure Virtual Machines Want to Get Certified? Join our Windows Server 2012 "Early Experts" Study Group

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• Wrapping ASP.NET Client Callbacks

  - by Ricardo Peres

  Client Callbacks are probably the less known (and I dare say, less loved) of all the AJAX options in ASP.NET, which also include the UpdatePanel, Page Methods and Web Services. The reason for that, I believe, is it’s relative complexity: Get a reference to a JavaScript function; Dynamically register function that calls the above reference; Have a JavaScript handler call the registered function. However, it has some the nice advantage of being self-contained, that is, doesn’t need additional files, such as web services, JavaScript libraries, etc, or static methods declared on a page, or any kind of attributes. So, here’s what I want to do: Have a DOM element which exposes a method that is executed server side, passing it a string and returning a string; Have a server-side event that handles the client-side call; Have two client-side user-supplied callback functions for handling the success and error results. I’m going to develop a custom control without user interface that does the registration of the client JavaScript method as well as a server-side event that can be hooked by some handler on a page. My markup will look like this: 1: <script type="text/javascript"> 1:  2:  3: function onCallbackSuccess(result, context) 4: { 5: } 6:  7: function onCallbackError(error, context) 8: { 9: } 10:  </script> 2: <my:CallbackControl runat="server" ID="callback" SendAllData="true" OnCallback="OnCallback"/> The control itself looks like this: 1: public class CallbackControl : Control, ICallbackEventHandler 2: { 3: #region Public constructor 4: public CallbackControl() 5: { 6: this.SendAllData = false; 7: this.Async = true; 8: } 9: #endregion 10:  11: #region Public properties and events 12: public event EventHandler<CallbackEventArgs> Callback; 13:  14: [DefaultValue(true)] 15: public Boolean Async 16: { 17: get; 18: set; 19: } 20:  21: [DefaultValue(false)] 22: public Boolean SendAllData 23: { 24: get; 25: set; 26: } 27:  28: #endregion 29:  30: #region Protected override methods 31:  32: protected override void Render(HtmlTextWriter writer) 33: { 34: writer.AddAttribute(HtmlTextWriterAttribute.Id, this.ClientID); 35: writer.RenderBeginTag(HtmlTextWriterTag.Span); 36:  37: base.Render(writer); 38:  39: writer.RenderEndTag(); 40: } 41:  42: protected override void OnInit(EventArgs e) 43: { 44: String reference = this.Page.ClientScript.GetCallbackEventReference(this, "arg", "onCallbackSuccess", "context", "onCallbackError", this.Async); 45: String script = String.Concat("\ndocument.getElementById('", this.ClientID, "').callback = function(arg, context, onCallbackSuccess, onCallbackError){", ((this.SendAllData == true) ? "__theFormPostCollection.length = 0; __theFormPostData = ''; WebForm_InitCallback(); " : String.Empty), reference, ";};\n"); 46:  47: this.Page.ClientScript.RegisterStartupScript(this.GetType(), String.Concat("callback", this.ClientID), script, true); 48:  49: base.OnInit(e); 50: } 51:  52: #endregion 53:  54: #region Protected virtual methods 55: protected virtual void OnCallback(CallbackEventArgs args) 56: { 57: EventHandler<CallbackEventArgs> handler = this.Callback; 58:  59: if (handler != null) 60: { 61: handler(this, args); 62: } 63: } 64:  65: #endregion 66:  67: #region ICallbackEventHandler Members 68:  69: String ICallbackEventHandler.GetCallbackResult() 70: { 71: CallbackEventArgs args = new CallbackEventArgs(this.Context.Items["Data"] as String); 72:  73: this.OnCallback(args); 74:  75: return (args.Result); 76: } 77:  78: void ICallbackEventHandler.RaiseCallbackEvent(String eventArgument) 79: { 80: this.Context.Items["Data"] = eventArgument; 81: } 82:  83: #endregion 84: } And the event argument class: 1: [Serializable] 2: public class CallbackEventArgs : EventArgs 3: { 4: public CallbackEventArgs(String argument) 5: { 6: this.Argument = argument; 7: this.Result = String.Empty; 8: } 9:  10: public String Argument 11: { 12: get; 13: private set; 14: } 15:  16: public String Result 17: { 18: get; 19: set; 20: } 21: } You will notice two properties on the CallbackControl: Async: indicates if the call should be made asynchronously or synchronously (the default); SendAllData: indicates if the callback call will include the view and control state of all of the controls on the page, so that, on the server side, they will have their properties set when the Callback event is fired. The CallbackEventArgs class exposes two properties: Argument: the read-only argument passed to the client-side function; Result: the result to return to the client-side callback function, set from the Callback event handler. An example of an handler for the Callback event would be: 1: protected void OnCallback(Object sender, CallbackEventArgs e) 2: { 3: e.Result = String.Join(String.Empty, e.Argument.Reverse()); 4: } Finally, in order to fire the Callback event from the client, you only need this: 1: <input type="text" id="input"/> 2: <input type="button" value="Get Result" onclick="document.getElementById('callback').callback(callback(document.getElementById('input').value, 'context', onCallbackSuccess, onCallbackError))"/> The syntax of the callback function is: arg: some string argument; context: some context that will be passed to the callback functions (success or failure); callbackSuccessFunction: some function that will be called when the callback succeeds; callbackFailureFunction: some function that will be called if the callback fails for some reason. Give it a try and see if it helps!

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• Using SQL Execution Plans to discover the Swedish alphabet

  - by Rob Farley

  SQL Server is quite remarkable in a bunch of ways. In this post, I’m using the way that the Query Optimizer handles LIKE to keep it SARGable, the Execution Plans that result, Collations, and PowerShell to come up with the Swedish alphabet. SARGability is the ability to seek for items in an index according to a particular set of criteria. If you don’t have SARGability in play, you need to scan the whole index (or table if you don’t have an index). For example, I can find myself in the phonebook easily, because it’s sorted by LastName and I can find Farley in there by moving to the Fs, and so on. I can’t find everyone in my suburb easily, because the phonebook isn’t sorted that way. I can’t even find people who have six letters in their last name, because also the book is sorted by LastName, it’s not sorted by LEN(LastName). This is all stuff I’ve looked at before, including in the talk I gave at SQLBits in October 2010. If I try to find everyone who’s names start with F, I can do that using a query a bit like: SELECT LastName FROM dbo.PhoneBook WHERE LEFT(LastName,1) = 'F'; Unfortunately, the Query Optimizer doesn’t realise that all the entries that satisfy LEFT(LastName,1) = 'F' will be together, and it has to scan the whole table to find them. But if I write: SELECT LastName FROM dbo.PhoneBook WHERE LastName LIKE 'F%'; then SQL is smart enough to understand this, and performs an Index Seek instead. To see why, I look further into the plan, in particular, the properties of the Index Seek operator. The ToolTip shows me what I’m after: You’ll see that it does a Seek to find any entries that are at least F, but not yet G. There’s an extra Predicate in there (a Residual Predicate if you like), which checks that each LastName is really LIKE F% – I suppose it doesn’t consider that the Seek Predicate is quite enough – but most of the benefit is seen by its working out the Seek Predicate, filtering to just the “at least F but not yet G” section of the data. This got me curious though, particularly about where the G comes from, and whether I could leverage it to create the Swedish alphabet. I know that in the Swedish language, there are three extra letters that appear at the end of the alphabet. One of them is ä that appears in the word Västerås. It turns out that Västerås is quite hard to find in an index when you’re looking it up in a Swedish map. I talked about this briefly in my five-minute talk on Collation from SQLPASS (the one which was slightly less than serious). So by looking at the plan, I can work out what the next letter is in the alphabet of the collation used by the column. In other words, if my alphabet were Swedish, I’d be able to tell what the next letter after F is – just in case it’s not G. It turns out it is… Yes, the Swedish letter after F is G. But I worked this out by using a copy of my PhoneBook table that used the Finnish_Swedish_CI_AI collation. I couldn’t find how the Query Optimizer calculates the G, and my friend Paul White (@SQL_Kiwi) tells me that it’s frustratingly internal to the QO. He’s particularly smart, even if he is from New Zealand. To investigate further, I decided to do some PowerShell, leveraging the Get-SqlPlan function that I blogged about recently (make sure you also have the SqlServerCmdletSnapin100 snap-in added). I started by indicating that I was going to use Finnish_Swedish_CI_AI as my collation of choice, and that I’d start whichever letter cam straight after the number 9. I figure that this is a cheat’s way of guessing the first letter of the alphabet (but it doesn’t actually work in Unicode – luckily I’m using varchar not nvarchar. Actually, there are a few aspects of this code that only work using ASCII, so apologies if you were wanting to apply it to Greek, Japanese, etc). I also initialised my $alphabet variable. $collation = 'Finnish_Swedish_CI_AI'; $firstletter = '9'; $alphabet = ''; Now I created the table for my test. A single field would do, and putting a Clustered Index on it would suffice for the Seeks. Invoke-Sqlcmd -server . -data tempdb -query "create table dbo.collation_test (col varchar(10) collate $collation primary key);" Now I get into the looping. $c = $firstletter; $stillgoing = $true; while ($stillgoing) { I construct the query I want, seeking for entries which start with whatever $c has reached, and get the plan for it: $query = "select col from dbo.collation_test where col like '$($c)%';"; [xml] $pl = get-sqlplan $query "." "tempdb"; At this point, my $pl variable is a scary piece of XML, representing the execution plan. A bit of hunting through it showed me that the EndRange element contained what I was after, and that if it contained NULL, then I was done. $stillgoing = ($pl.ShowPlanXML.BatchSequence.Batch.Statements.StmtSimple.QueryPlan.RelOp.IndexScan.SeekPredicates.SeekPredicateNew.SeekKeys.EndRange -ne $null); Now I could grab the value out of it (which came with apostrophes that needed stripping), and append that to my $alphabet variable.   if ($stillgoing)   {  $c=$pl.ShowPlanXML.BatchSequence.Batch.Statements.StmtSimple.QueryPlan.RelOp.IndexScan.SeekPredicates.SeekPredicateNew.SeekKeys.EndRange.RangeExpressions.ScalarOperator.ScalarString.Replace("'","");     $alphabet += $c;   } Finally, finishing the loop, dropping the table, and showing my alphabet! } Invoke-Sqlcmd -server . -data tempdb -query "drop table dbo.collation_test;"; $alphabet; When I run all this, I see that the Swedish alphabet is ABCDEFGHIJKLMNOPQRSTUVXYZÅÄÖ, which matches what I see at Wikipedia. Interesting to see that the letters on the end are still there, even with Case Insensitivity. Turns out they’re not just “letters with accents”, they’re letters in their own right. I’m sure you gave up reading long ago, and really aren’t that fazed about the idea of doing this using PowerShell. I chose PowerShell because I’d already come up with an easy way of grabbing the estimated plan for a query, and PowerShell does allow for easy navigation of XML. I find the most interesting aspect of this as the fact that the Query Optimizer uses the next letter of the alphabet to maintain the SARGability of LIKE. I’m hoping they do something similar for a whole bunch of operations. Oh, and the fact that you know how to find stuff in the IKEA catalogue. Footnote: If you are interested in whether this works in other languages, you might want to consider the following screenshot, which shows that in principle, it should work with Japanese. It might be a bit harder to run this in PowerShell though, as I’m not sure how it translates. In Hiragana, the Japanese alphabet starts ?, ?, ?, ?, ?, ...

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• Using jQuery Live instead of jQuery Hover function

  - by hajan

  Let’s say we have a case where we need to create mouseover / mouseout functionality for a list which will be dynamically filled with data on client-side. We can use jQuery hover function, which handles the mouseover and mouseout events with two functions. See the following example: <!DOCTYPE html> <html lang="en"> <head id="Head1" runat="server">     <title>jQuery Mouseover / Mouseout Demo</title>     <script type="text/javascript" src="http://ajax.aspnetcdn.com/ajax/jquery/jquery-1.4.4.js"></script>     <style type="text/css">         .hover { color:Red; cursor:pointer;}     </style>     <script type="text/javascript">         $(function () {             $("li").hover(               function () {                   $(this).addClass("hover");               },               function () {                   $(this).removeClass("hover");               });         });     </script> </head> <body>     <form id="form2" runat="server">     <ul>         <li>Data 1</li>         <li>Data 2</li>         <li>Data 3</li>         <li>Data 4</li>         <li>Data 5</li>         <li>Data 6</li>     </ul>     </form> </body> </html> Now, if you have situation where you want to add new data dynamically... Lets say you have a button to add new item in the list. Add the following code right bellow the </ul> tag <input type="text" id="txtItem" /> <input type="button" id="addNewItem" value="Add New Item" /> And add the following button click functionality: //button add new item functionality $("#addNewItem").click(function (event) {     event.preventDefault();     $("<li>" + $("#txtItem").val() + "</li>").appendTo("ul"); }); The mouse over effect won't work for the newly added items. Therefore, we need to use live or delegate function. These both do the same job. The main difference is that for some cases delegate is considered a bit faster, and can be used in chaining. In our case, we can use both. I will use live function. $("li").live("mouseover mouseout",   function (event) {       if (event.type == "mouseover") $(this).addClass("hover");       else $(this).removeClass("hover");   }); The complete code is: <!DOCTYPE html> <html lang="en"> <head id="Head1" runat="server">     <title>jQuery Mouseover / Mouseout Demo</title>     <script type="text/javascript" src="http://ajax.aspnetcdn.com/ajax/jquery/jquery-1.4.4.js"></script>     <style type="text/css">         .hover { color:Red; cursor:pointer;}     </style>     <script type="text/javascript">         $(function () {             $("li").live("mouseover mouseout",               function (event) {                   if (event.type == "mouseover") $(this).addClass("hover");                   else $(this).removeClass("hover");               });             //button add new item functionality             $("#addNewItem").click(function (event) {                 event.preventDefault();                 $("<li>" + $("#txtItem").val() + "</li>").appendTo("ul");             });         });     </script> </head> <body>     <form id="form2" runat="server">     <ul>         <li>Data 1</li>         <li>Data 2</li>         <li>Data 3</li>         <li>Data 4</li>         <li>Data 5</li>         <li>Data 6</li>     </ul>          <input type="text" id="txtItem" />     <input type="button" id="addNewItem" value="Add New Item" />     </form> </body> </html> So, basically when replacing hover with live, you see we use the mouseover and mouseout names for both events. Check the working demo which is available HERE. Hope this was useful blog for you. Hope it’s helpful. HajanReference blog: http://codeasp.net/blogs/hajan/microsoft-net/1260/using-jquery-live-instead-of-jquery-hover-function

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• Thread placement policies on NUMA systems - update

  - by Dave

  In a prior blog entry I noted that Solaris used a "maximum dispersal" placement policy to assign nascent threads to their initial processors. The general idea is that threads should be placed as far away from each other as possible in the resource topology in order to reduce resource contention between concurrently running threads. This policy assumes that resource contention -- pipelines, memory channel contention, destructive interference in the shared caches, etc -- will likely outweigh (a) any potential communication benefits we might achieve by packing our threads more densely onto a subset of the NUMA nodes, and (b) benefits of NUMA affinity between memory allocated by one thread and accessed by other threads. We want our threads spread widely over the system and not packed together. Conceptually, when placing a new thread, the kernel picks the least loaded node NUMA node (the node with lowest aggregate load average), and then the least loaded core on that node, etc. Furthermore, the kernel places threads onto resources -- sockets, cores, pipelines, etc -- without regard to the thread's process membership. That is, initial placement is process-agnostic. Keep reading, though. This description is incorrect. On Solaris 10 on a SPARC T5440 with 4 x T2+ NUMA nodes, if the system is otherwise unloaded and we launch a process that creates 20 compute-bound concurrent threads, then typically we'll see a perfect balance with 5 threads on each node. We see similar behavior on an 8-node x86 x4800 system, where each node has 8 cores and each core is 2-way hyperthreaded. So far so good; this behavior seems in agreement with the policy I described in the 1st paragraph. I recently tried the same experiment on a 4-node T4-4 running Solaris 11. Both the T5440 and T4-4 are 4-node systems that expose 256 logical thread contexts. To my surprise, all 20 threads were placed onto just one NUMA node while the other 3 nodes remained completely idle. I checked the usual suspects such as processor sets inadvertently left around by colleagues, processors left offline, and power management policies, but the system was configured normally. I then launched multiple concurrent instances of the process, and, interestingly, all the threads from the 1st process landed on one node, all the threads from the 2nd process landed on another node, and so on. This happened even if I interleaved thread creating between the processes, so I was relatively sure the effect didn't related to thread creation time, but rather that placement was a function of process membership. I this point I consulted the Solaris sources and talked with folks in the Solaris group. The new Solaris 11 behavior is intentional. The kernel is no longer using a simple maximum dispersal policy, and thread placement is process membership-aware. Now, even if other nodes are completely unloaded, the kernel will still try to pack new threads onto the home lgroup (socket) of the primordial thread until the load average of that node reaches 50%, after which it will pick the next least loaded node as the process's new favorite node for placement. On the T4-4 we have 64 logical thread contexts (strands) per socket (lgroup), so if we launch 48 concurrent threads we will find 32 placed on one node and 16 on some other node. If we launch 64 threads we'll find 32 and 32. That means we can end up with our threads clustered on a small subset of the nodes in a way that's quite different that what we've seen on Solaris 10. So we have a policy that allows process-aware packing but reverts to spreading threads onto other nodes if a node becomes too saturated. It turns out this policy was enabled in Solaris 10, but certain bugs suppressed the mixed packing/spreading behavior. There are configuration variables in /etc/system that allow us to dial the affinity between nascent threads and their primordial thread up and down: see lgrp_expand_proc_thresh, specifically. In the OpenSolaris source code the key routine is mpo_update_tunables(). This method reads the /etc/system variables and sets up some global variables that will subsequently be used by the dispatcher, which calls lgrp_choose() in lgrp.c to place nascent threads. Lgrp_expand_proc_thresh controls how loaded an lgroup must be before we'll consider homing a process's threads to another lgroup. Tune this value lower to have it spread your process's threads out more. To recap, the 'new' policy is as follows. Threads from the same process are packed onto a subset of the strands of a socket (50% for T-series). Once that socket reaches the 50% threshold the kernel then picks another preferred socket for that process. Threads from unrelated processes are spread across sockets. More precisely, different processes may have different preferred sockets (lgroups). Beware that I've simplified and elided details for the purposes of explication. The truth is in the code. Remarks: It's worth noting that initial thread placement is just that. If there's a gross imbalance between the load on different nodes then the kernel will migrate threads to achieve a better and more even distribution over the set of available nodes. Once a thread runs and gains some affinity for a node, however, it becomes "stickier" under the assumption that the thread has residual cache residency on that node, and that memory allocated by that thread resides on that node given the default "first-touch" page-level NUMA allocation policy. Exactly how the various policies interact and which have precedence under what circumstances could the topic of a future blog entry. The scheduler is work-conserving. The x4800 mentioned above is an interesting system. Each of the 8 sockets houses an Intel 7500-series processor. Each processor has 3 coherent QPI links and the system is arranged as a glueless 8-socket twisted ladder "mobius" topology. Nodes are either 1 or 2 hops distant over the QPI links. As an aside the mapping of logical CPUIDs to physical resources is rather interesting on Solaris/x4800. On SPARC/Solaris the CPUID layout is strictly geographic, with the highest order bits identifying the socket, the next lower bits identifying the core within that socket, following by the pipeline (if present) and finally the logical thread context ("strand") on the core. But on Solaris on the x4800 the CPUID layout is as follows. [6:6] identifies the hyperthread on a core; bits [5:3] identify the socket, or package in Intel terminology; bits [2:0] identify the core within a socket. Such low-level details should be of interest only if you're binding threads -- a bad idea, the kernel typically handles placement best -- or if you're writing NUMA-aware code that's aware of the ambient placement and makes decisions accordingly. Solaris introduced the so-called critical-threads mechanism, which is expressed by putting a thread into the FX scheduling class at priority 60. The critical-threads mechanism applies to placement on cores, not on sockets, however. That is, it's an intra-socket policy, not an inter-socket policy. Solaris 11 introduces the Power Aware Dispatcher (PAD) which packs threads instead of spreading them out in an attempt to be able to keep sockets or cores at lower power levels. Maximum dispersal may be good for performance but is anathema to power management. PAD is off by default, but power management polices constitute yet another confounding factor with respect to scheduling and dispatching. If your threads communicate heavily -- one thread reads cache lines last written by some other thread -- then the new dense packing policy may improve performance by reducing traffic on the coherent interconnect. On the other hand if your threads in your process communicate rarely, then it's possible the new packing policy might result on contention on shared computing resources. Unfortunately there's no simple litmus test that says whether packing or spreading is optimal in a given situation. The answer varies by system load, application, number of threads, and platform hardware characteristics. Currently we don't have the necessary tools and sensoria to decide at runtime, so we're reduced to an empirical approach where we run trials and try to decide on a placement policy. The situation is quite frustrating. Relatedly, it's often hard to determine just the right level of concurrency to optimize throughput. (Understanding constructive vs destructive interference in the shared caches would be a good start. We could augment the lines with a small tag field indicating which strand last installed or accessed a line. Given that, we could augment the CPU with performance counters for misses where a thread evicts a line it installed vs misses where a thread displaces a line installed by some other thread.)

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• ASP.NET MVC JavaScript Routing

  - by zowens

  Have you ever done this sort of thing in your ASP.NET MVC view? The weird thing about this isn’t the alert function, it’s the code block containing the Url formation using the ASP.NET MVC UrlHelper. The terrible thing about this experience is the obvious lack of IntelliSense and this ugly inline JavaScript code. Inline JavaScript isn’t portable to other pages beyond the current page of execution. It is generally considered bad practice to use inline JavaScript in your public-facing pages. How ludicrous would it be to copy and paste the entire jQuery code base into your pages…? Not something you’d ever consider doing. The problem is that your URLs have to be generated by ASP.NET at runtime and really can’t be copied to your JavaScript code without some trickery. How about this? Does the hard-coded URL bother you? It really bothers me. The typical solution to this whole routing in JavaScript issue is to just hard-code your URLs into your JavaScript files and call it done. But what if your URLs change? You have to now go an track down the places in JavaScript and manually replace them. What if you get the pattern wrong? Do you have tests around it? This isn’t something you should have to worry about.   The Solution To Our Problems The solution is to port routing over to JavaScript. Does that sound daunting to you? It’s actually not very hard, but I decided to create my own generator that will do all the work for you. What I have created is a very basic port of the route formation feature of ASP.NET routing. It will generate the formatted URLs based on your routing patterns. Here’s how you’d do this: Does that feel familiar? It looks a lot like something you’d do inside of your ASP.NET MVC views… but this is inside of a JavaScript file… just a plain ol’ .js file.  Your first question might be why do you have to have that “.toUrl()” thing. The reason is that I wanted to make POST and GET requests dead simple. Here’s how you’d do a POST request (and the same would work with a GET request):   The first parameter is extra data passed to the post request and the second parameter is a function that handles the success of the POST request. If you’re familiar with jQuery’s Ajax goodness, you’ll know how to use it. (if not, check out http://api.jquery.com/jQuery.Post/ and the parameters are essentially the same). But we still haven’t gotten rid of the magic strings. We still have controller names and action names represented as strings. This is going to blow your mind… If you’ve seen T4MVC, this will look familiar. We’re essentially doing the same sort of thing with my JavaScript router, but we’re porting the concept to JavaScript. The good news is that parameters to the controllers are directly reflected in the action function, just like T4MVC. And the even better news… IntlliSense is easily transferred to the JavaScript version if you’re using Visual Studio as your JavaScript editor. The additional data parameter gives you the ability to pass extra routing data to the URL formatter.   About the Magic You may be wondering how this all work. It’s actually quite simple. I’ve built a simple jQuery pluggin (called routeManager) that hangs off the main jQuery namespace and routes all the URLs. Every time your solution builds, a routing file will be generated with this pluggin, all your route and controller definitions along with your documentation. Then by the power of Visual Studio, you get some really slick IntelliSense that is hard to live without. But there are a few steps you have to take before this whole thing is going to work. First and foremost, you need a reference to the JsRouting.Core.dll to your projects containing controllers or routes. Second, you have to specify your routes in a bit of a non-standard way. See, we can’t just pull routes out of your App_Start in your Global.asax. We force you to build a route source like this: The way we determine the routes is by pulling in all RouteSources and generating routes based upon the mapped routes. There are various reasons why we can’t use RouteCollection (different post for another day)… but in this case, you get the same route mapping experience. Converting the RouteSource to a RouteCollection is trivial (there’s an extension method for that). Next thing you have to do is generate a documentation XML file. This is done by going to the project settings, going to the build tab and clicking the checkbox. (this isn’t required, but nice to have). The final thing you need to do is hook up the generation mechanism. Pop open your project file and look for the AfterBuild step. Now change the build step task to look like this: The “PathToOutputExe” is the path to the JsRouting.Output.exe file. This will change based on where you put the EXE. The “PathToOutputJs” is a path to the output JavaScript file. The “DicrectoryOfAssemblies” is a path to the directory containing controller and routing DLLs. The JsRouting.Output.exe executable pulls in all these assemblies and scans them for controllers and route sources.   Now that wasn’t too bad, was it :)   The State of the Project This is definitely not complete… I have a lot of plans for this little project of mine. For starters, I need to look at the generation mechanism. Either I will be creating a utility that will do the project file manipulation or I will go a different direction. I’d like some feedback on this if you feel partial either way. Another thing I don’t support currently is areas. While this wouldn’t be too hard to support, I just don’t use areas and I wanted something up quickly (this is, after all, for a current project of mine). I’ll be adding support shortly. There are a few things that I haven’t covered in this post that I will most certainly be covering in another post, such as routing constraints and how these will be translated to JavaScript. I decided to open source this whole thing, since it’s a nice little utility I think others should really be using. Currently we’re using ASP.NET MVC 2, but it should work with MVC 3 as well. I’ll upgrade it as soon as MVC 3 is released. Along those same lines, I’m investigating how this could be put on the NuGet feed. Show me the Bits! OK, OK! The code is posted on my GitHub account. Go nuts. Tell me what you think. Tell me what you want. Tell me that you hate it. All feedback is welcome! https://github.com/zowens/ASP.NET-MVC-JavaScript-Routing

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• CLR Version issues with CorBindRuntimeEx

  - by Rick Strahl

  I’m working on an older FoxPro application that’s using .NET Interop and this app loads its own copy of the .NET runtime through some of our own tools (wwDotNetBridge). This all works fine and it’s fairly straightforward to load and host the runtime and then make calls against it. I’m writing this up for myself mostly because I’ve been bitten by these issues repeatedly and spend 15 minutes each However, things get tricky when calling specific versions of the .NET runtime since .NET 4.0 has shipped. Basically we need to be able to support both .NET 2.0 and 4.0 and we’re currently doing it with the same assembly – a .NET 2.0 assembly that is the AppDomain entry point. This works as .NET 4.0 can easily host .NET 2.0 assemblies and the functionality in the 2.0 assembly provides all the features we need to call .NET 4.0 assemblies via Reflection. In wwDotnetBridge we provide a load flag that allows specification of the runtime version to use. Something like this: do wwDotNetBridge LOCAL loBridge as wwDotNetBridge loBridge = CreateObject("wwDotNetBridge","v4.0.30319") and this works just fine in most cases.  If I specify V4 internally that gets fixed up to a whole version number like “v4.0.30319” which is then actually used to host the .NET runtime. Specifically the ClrVersion setting is handled in this Win32 DLL code that handles loading the runtime for me: /// Starts up the CLR and creates a Default AppDomain DWORD WINAPI ClrLoad(char *ErrorMessage, DWORD *dwErrorSize) { if (spDefAppDomain) return 1; //Retrieve a pointer to the ICorRuntimeHost interface HRESULT hr = CorBindToRuntimeEx( ClrVersion, //Retrieve latest version by default L"wks", //Request a WorkStation build of the CLR STARTUP_LOADER_OPTIMIZATION_MULTI_DOMAIN | STARTUP_CONCURRENT_GC, CLSID_CorRuntimeHost, IID_ICorRuntimeHost, (void**)&spRuntimeHost ); if (FAILED(hr)) { *dwErrorSize = SetError(hr,ErrorMessage); return hr; } //Start the CLR hr = spRuntimeHost->Start(); if (FAILED(hr)) return hr; CComPtr<IUnknown> pUnk; WCHAR domainId[50]; swprintf(domainId,L"%s_%i",L"wwDotNetBridge",GetTickCount()); hr = spRuntimeHost->CreateDomain(domainId,NULL,&pUnk); hr = pUnk->QueryInterface(&spDefAppDomain.p); if (FAILED(hr)) return hr; return 1; } CorBindToRuntimeEx allows for a specific .NET version string to be supplied which is what I’m doing via an API call from the FoxPro code. The behavior of CorBindToRuntimeEx is a bit finicky however. The documentation states that NULL should load the latest version of the .NET runtime available on the machine – but it actually doesn’t. As far as I can see – regardless of runtime overrides even in the .config file – NULL will always load .NET 2.0 even if 4.0 is installed. <supportedRuntime> .config File Settings Things get even more unpredictable once you start adding runtime overrides into the application’s .config file. In my scenario working inside of Visual FoxPro this would be VFP9.exe.config in the FoxPro installation folder (not the current folder). If I have a specific runtime override in the .config file like this: <?xml version="1.0"?> <configuration> <startup> <supportedRuntime version="v2.0.50727" /> </startup> </configuration> Not surprisingly with this I can load a .NET 2.0  runtime, but I will not be able to load Version 4.0 of the .NET runtime even if I explicitly specify it in my call to ClrLoad. Worse I don’t get an error – it will just go ahead and hand me a V2 version of the runtime and assume that’s what I wanted. Yuck! However, if I set the supported runtime to V4 in the .config file: <?xml version="1.0"?> <configuration> <startup> <supportedRuntime version="v4.0.30319" /> </startup> </configuration> Then I can load both V4 and V2 of the runtime. Specifying NULL however will STILL only give me V2 of the runtime. Again this seems pretty inconsistent. If you’re hosting runtimes make sure you check which version of the runtime is actually loading first to ensure you get the one you’re looking for. If the wrong version loads – say 2.0 and you want 4.0 - and you then proceed to load 4.0 assemblies they will all fail to load due to version mismatches. This is how all of this started – I had a bunch of assemblies that weren’t loading and it took a while to figure out that the host was running the wrong version of the CLR and therefore caused the assemblies loading to fail. Arrggh! <supportedRuntime> and Debugger Version <supportedRuntime> also affects the use of the .NET debugger when attached to the target application. Whichever runtime is specified in the key is the version of the debugger that fires up. This can have some interesting side effects. If you load a .NET 2.0 assembly but <supportedRuntime> points at V4.0 (or vice versa) the debugger will never fire because it can only debug in the appropriate runtime version. This has bitten me on several occasions where code runs just fine but the debugger will just breeze by breakpoints without notice. The default version for the debugger is the latest version installed on the system if <supportedRuntime> is not set. Summary Besides all the hassels, I’m thankful I can build a .NET 2.0 assembly and have it host .NET 4.0 and call .NET 4.0 code. This way we’re able to ship a single assembly that provides functionality that supports both .NET 2 and 4 without having to have separate DLLs for both which would be a deployment and update nightmare. The MSDN documentation does point at newer hosting API’s specifically for .NET 4.0 which are way more complicated and even less documented but that doesn’t help here because the runtime needs to be able to host both .NET 4.0 and 2.0. Not pleased about that – the new APIs look way more complex and of course they’re not available with older versions of the runtime installed which in our case makes them useless to me in this scenario where I have to support .NET 2.0 hosting (to provide greater ‘built-in’ platform support). Once you know the behavior above, it’s manageable. However, it’s quite easy to get tripped up here because there are multiple combinations that can really screw up behaviors.© Rick Strahl, West Wind Technologies, 2005-2011Posted in .NET  FoxPro  

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• Using SSIS to send a HTML E-Mail Message with built-in table of Counts.

  - by Kevin Shyr

  For the record, this can be just as easily done with a .NET class with a DLL call.  The two major reasons for this ending up as a SSIS package are: There are a lot of SQL resources for maintenance, but not as many .NET developers. There is an existing automated process that links up SQL Jobs (more on that in the next post), and this is part of that process.   To start, this is what the SSIS looks like: The first part of the control flow is just for the override scenario.   In the Execute SQL Task, it calls a stored procedure, which already formats the result into XML by using "FOR XML PATH('Row'), ROOT(N'FieldingCounts')".  The result XML string looks like this: <FieldingCounts>   <Row>     <CellId>M COD</CellId>     <Mailed>64</Mailed>     <ReMailed>210</ReMailed>     <TotalMail>274</TotalMail>     <EMailed>233</EMailed>     <TotalSent>297</TotalSent>   </Row>   <Row>     <CellId>M National</CellId>     <Mailed>11</Mailed>     <ReMailed>59</ReMailed>     <TotalMail>70</TotalMail>     <EMailed>90</EMailed>     <TotalSent>101</TotalSent>   </Row>   <Row>     <CellId>U COD</CellId>     <Mailed>91</Mailed>     <ReMailed>238</ReMailed>     <TotalMail>329</TotalMail>     <EMailed>291</EMailed>     <TotalSent>382</TotalSent>   </Row>   <Row>     <CellId>U National</CellId>     <Mailed>63</Mailed>     <ReMailed>286</ReMailed>     <TotalMail>349</TotalMail>     <EMailed>374</EMailed>     <TotalSent>437</TotalSent>   </Row> </FieldingCounts>  This result is saved into an internal SSIS variable with the following settings on the General tab and the Result Set tab:   Now comes the trickier part.  We need to use the XML Task to format the XML string result into an HTML table, and I used Direct input XSLT And here is the code of XSLT: <xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"> <xsl:output method="html" indent="yes"/>   <xsl:template match="/ROOT">         <table border="1" cellpadding="6">           <tr>             <td></td>             <td>Mailed</td>             <td>Re-mailed</td>             <td>Total Mail (Mailed, Re-mailed)</td>             <td>E-mailed</td>             <td>Total Sent (Mailed, E-mailed)</td>           </tr>           <xsl:for-each select="FieldingCounts/Row">             <tr>               <xsl:for-each select="./*">                 <td>                   <xsl:value-of select="." />                 </td>               </xsl:for-each>             </tr>           </xsl:for-each>         </table>   </xsl:template> </xsl:stylesheet>    Then a script task is used to send out an HTML email (as we are all painfully aware that SSIS Send Mail Task only sends plain text) Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 using System; using System.Data; using Microsoft.SqlServer.Dts.Runtime; using System.Windows.Forms; using System.Net.Mail; using System.Net;   namespace ST_b829a2615e714bcfb55db0ce97be3901.csproj {     [System.AddIn.AddIn("ScriptMain", Version = "1.0", Publisher = "", Description = "")]     public partial class ScriptMain : Microsoft.SqlServer.Dts.Tasks.ScriptTask.VSTARTScriptObjectModelBase     {           #region VSTA generated code         enum ScriptResults         {             Success = Microsoft.SqlServer.Dts.Runtime.DTSExecResult.Success,             Failure = Microsoft.SqlServer.Dts.Runtime.DTSExecResult.Failure         };         #endregion           public void Main()         {             String EmailMsgBody = String.Format("<HTML><BODY><P>{0}</P><P>{1}</P></BODY></HTML>"                                                 , Dts.Variables["Config_SMTP_MessageSourceText"].Value.ToString()                                                 , Dts.Variables["InternalStr_CountResultAfterXSLT"].Value.ToString());             MailMessage EmailCountMsg = new MailMessage(Dts.Variables["Config_SMTP_From"].Value.ToString().Replace(";", ",")                                                         , Dts.Variables["Config_SMTP_Success_To"].Value.ToString().Replace(";", ",")                                                         , Dts.Variables["Config_SMTP_SubjectLinePrefix"].Value.ToString() + " " + Dts.Variables["InternalStr_FieldingDate"].Value.ToString()                                                         , EmailMsgBody);             //EmailCountMsg.From.             EmailCountMsg.CC.Add(Dts.Variables["Config_SMTP_Success_CC"].Value.ToString().Replace(";", ","));             EmailCountMsg.IsBodyHtml = true;               SmtpClient SMTPForCount = new SmtpClient(Dts.Variables["Config_SMTP_ServerAddress"].Value.ToString());             SMTPForCount.Credentials = CredentialCache.DefaultNetworkCredentials;               SMTPForCount.Send(EmailCountMsg);               Dts.TaskResult = (int)ScriptResults.Success;         }     } } Note on this code: notice the email list has Replace(";", ",").  This is only here because the list is configurable in the SQL Job Step at Set Values, which does not react well with colons as email separator, but system.Net.Mail only handles comma as email separator, hence the extra replace in the string. The result is a nicely formatted email message with count information:

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• how to use serial port in UDK using windows DLL and DLLBind directive?

  - by Shayan Abbas

  I want to use serial port in UDK, For that purpose i use a windows DLL and DLLBind directive. I have a thread in windows DLL for serial port data recieve event. My problem is: this thread doesn't work properly. Please Help me. below is my code SerialPortDLL Code: // SerialPortDLL.cpp : Defines the exported functions for the DLL application. // #include "stdafx.h" #include "Cport.h" extern "C" { // This is an example of an exported variable //SERIALPORTDLL_API int nSerialPortDLL=0; // This is an example of an exported function. //SERIALPORTDLL_API int fnSerialPortDLL(void) //{ // return 42; //} CPort *sp; __declspec(dllexport) void Open(wchar_t* portName) { sp = new CPort(portName); //MessageBox(0,L"ha ha!!!",L"ha ha",0); //MessageBox(0,portName,L"ha ha",0); } __declspec(dllexport) void Close() { sp->Close(); MessageBox(0,L"ha ha!!!",L"ha ha",0); } __declspec(dllexport) wchar_t *GetData() { return sp->GetData(); } __declspec(dllexport) unsigned int GetDSR() { return sp->getDSR(); } __declspec(dllexport) unsigned int GetCTS() { return sp->getCTS(); } __declspec(dllexport) unsigned int GetRing() { return sp->getRing(); } } CPort class code: #include "stdafx.h" #include "CPort.h" #include "Serial.h" CSerial serial; HANDLE HandleOfThread; LONG lLastError = ERROR_SUCCESS; bool fContinue = true; HANDLE hevtOverlapped; HANDLE hevtStop; OVERLAPPED ov = {0}; //char szBuffer[101] = ""; wchar_t *szBuffer = L""; wchar_t *data = L""; DWORD WINAPI ThreadHandler( LPVOID lpParam ) { // Keep reading data, until an EOF (CTRL-Z) has been received do { MessageBox(0,L"ga ga!!!",L"ga ga",0); //Sleep(10); // Wait for an event lLastError = serial.WaitEvent(&ov); if (lLastError != ERROR_SUCCESS) { //LOG( " Unable to wait for a COM-port event" ); } // Setup array of handles in which we are interested HANDLE ahWait[2]; ahWait[0] = hevtOverlapped; ahWait[1] = hevtStop; // Wait until something happens switch (::WaitForMultipleObjects(sizeof(ahWait)/sizeof(*ahWait),ahWait,FALSE,INFINITE)) { case WAIT_OBJECT_0: { // Save event const CSerial::EEvent eEvent = serial.GetEventType(); // Handle break event if (eEvent & CSerial::EEventBreak) { //LOG( " ### BREAK received ###" ); } // Handle CTS event if (eEvent & CSerial::EEventCTS) { //LOG( " ### Clear to send %s ###", serial.GetCTS() ? "on":"off" ); } // Handle DSR event if (eEvent & CSerial::EEventDSR) { //LOG( " ### Data set ready %s ###", serial.GetDSR() ? "on":"off" ); } // Handle error event if (eEvent & CSerial::EEventError) { switch (serial.GetError()) { case CSerial::EErrorBreak: /*LOG( " Break condition" );*/ break; case CSerial::EErrorFrame: /*LOG( " Framing error" );*/ break; case CSerial::EErrorIOE: /*LOG( " IO device error" );*/ break; case CSerial::EErrorMode: /*LOG( " Unsupported mode" );*/ break; case CSerial::EErrorOverrun: /*LOG( " Buffer overrun" );*/ break; case CSerial::EErrorRxOver: /*LOG( " Input buffer overflow" );*/ break; case CSerial::EErrorParity: /*LOG( " Input parity error" );*/ break; case CSerial::EErrorTxFull: /*LOG( " Output buffer full" );*/ break; default: /*LOG( " Unknown" );*/ break; } } // Handle ring event if (eEvent & CSerial::EEventRing) { //LOG( " ### RING ###" ); } // Handle RLSD/CD event if (eEvent & CSerial::EEventRLSD) { //LOG( " ### RLSD/CD %s ###", serial.GetRLSD() ? "on" : "off" ); } // Handle data receive event if (eEvent & CSerial::EEventRecv) { // Read data, until there is nothing left DWORD dwBytesRead = 0; do { // Read data from the COM-port lLastError = serial.Read(szBuffer,33,&dwBytesRead); if (lLastError != ERROR_SUCCESS) { //LOG( "Unable to read from COM-port" ); } if( dwBytesRead == 33 && szBuffer[0]=='$' ) { // Finalize the data, so it is a valid string szBuffer[dwBytesRead] = '\0'; ////LOG( "\n%s\n", szBuffer ); data = szBuffer; } } while (dwBytesRead > 0); } } break; case WAIT_OBJECT_0+1: { // Set the continue bit to false, so we'll exit fContinue = false; } break; default: { // Something went wrong //LOG( "Error while calling WaitForMultipleObjects" ); } break; } } while (fContinue); MessageBox(0,L"kka kk!!!",L"kka ga",0); return 0; } CPort::CPort(wchar_t *portName) { // Attempt to open the serial port (COM2) //lLastError = serial.Open(_T(portName),0,0,true); lLastError = serial.Open(portName,0,0,true); if (lLastError != ERROR_SUCCESS) { //LOG( "Unable to open COM-port" ); } // Setup the serial port (115200,8N1, which is the default setting) lLastError = serial.Setup(CSerial::EBaud115200,CSerial::EData8,CSerial::EParNone,CSerial::EStop1); if (lLastError != ERROR_SUCCESS) { //LOG( "Unable to set COM-port setting" ); } // Register only for the receive event lLastError = serial.SetMask(CSerial::EEventBreak | CSerial::EEventCTS | CSerial::EEventDSR | CSerial::EEventError | CSerial::EEventRing | CSerial::EEventRLSD | CSerial::EEventRecv); if (lLastError != ERROR_SUCCESS) { //LOG( "Unable to set COM-port event mask" ); } // Use 'non-blocking' reads, because we don't know how many bytes // will be received. This is normally the most convenient mode // (and also the default mode for reading data). lLastError = serial.SetupReadTimeouts(CSerial::EReadTimeoutNonblocking); if (lLastError != ERROR_SUCCESS) { //LOG( "Unable to set COM-port read timeout" ); } // Create a handle for the overlapped operations hevtOverlapped = ::CreateEvent(0,TRUE,FALSE,0);; if (hevtOverlapped == 0) { //LOG( "Unable to create manual-reset event for overlapped I/O" ); } // Setup the overlapped structure ov.hEvent = hevtOverlapped; // Open the "STOP" handle hevtStop = ::CreateEvent(0,TRUE,FALSE,_T("Overlapped_Stop_Event")); if (hevtStop == 0) { //LOG( "Unable to create manual-reset event for stop event" ); } HandleOfThread = CreateThread( NULL, 0, ThreadHandler, 0, 0, NULL); } CPort::~CPort() { //fContinue = false; //CloseHandle( HandleOfThread ); //serial.Close(); } void CPort::Close() { fContinue = false; CloseHandle( HandleOfThread ); serial.Close(); } wchar_t *CPort::GetData() { return data; } bool CPort::getCTS() { return serial.GetCTS(); } bool CPort::getDSR() { return serial.GetDSR(); } bool CPort::getRing() { return serial.GetRing(); } Unreal Script Code: class MyPlayerController extends GamePlayerController DLLBind(SerialPortDLL); dllimport final function Open(string portName); dllimport final function Close(); dllimport final function string GetData();

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• ASP.NET MVC 3 Hosting :: Error Handling and CustomErrors in ASP.NET MVC 3 Framework

  - by C. Miller

  So, what else is new in MVC 3? MVC 3 now has a GlobalFilterCollection that is automatically populated with a HandleErrorAttribute. This default FilterAttribute brings with it a new way of handling errors in your web applications. In short, you can now handle errors inside of the MVC pipeline. What does that mean? This gives you direct programmatic control over handling your 500 errors in the same way that ASP.NET and CustomErrors give you configurable control of handling your HTTP error codes. How does that work out? Think of it as a routing table specifically for your Exceptions, it's pretty sweet! Global Filters The new Global.asax file now has a RegisterGlobalFilters method that is used to add filters to the new GlobalFilterCollection, statically located at System.Web.Mvc.GlobalFilter.Filters. By default this method adds one filter, the HandleErrorAttribute. public class MvcApplication : System.Web.HttpApplication {     public static void RegisterGlobalFilters(GlobalFilterCollection filters)     {         filters.Add(new HandleErrorAttribute());     } HandleErrorAttributes The HandleErrorAttribute is pretty simple in concept: MVC has already adjusted us to using Filter attributes for our AcceptVerbs and RequiresAuthorization, now we are going to use them for (as the name implies) error handling, and we are going to do so on a (also as the name implies) global scale. The HandleErrorAttribute has properties for ExceptionType, View, and Master. The ExceptionType allows you to specify what exception that attribute should handle. The View allows you to specify which error view (page) you want it to redirect to. Last but not least, the Master allows you to control which master page (or as Razor refers to them, Layout) you want to render with, even if that means overriding the default layout specified in the view itself. public class MvcApplication : System.Web.HttpApplication {     public static void RegisterGlobalFilters(GlobalFilterCollection filters)     {         filters.Add(new HandleErrorAttribute         {             ExceptionType = typeof(DbException),             // DbError.cshtml is a view in the Shared folder.             View = "DbError",             Order = 2         });         filters.Add(new HandleErrorAttribute());     }Error Views All of your views still work like they did in the previous version of MVC (except of course that they can now use the Razor engine). However, a view that is used to render an error can not have a specified model! This is because they already have a model, and that is System.Web.Mvc.HandleErrorInfo @model System.Web.Mvc.HandleErrorInfo           @{     ViewBag.Title = "DbError"; } <h2>A Database Error Has Occurred</h2> @if (Model != null) {     <p>@Model.Exception.GetType().Name<br />     thrown in @Model.ControllerName @Model.ActionName</p> }Errors Outside of the MVC Pipeline The HandleErrorAttribute will only handle errors that happen inside of the MVC pipeline, better known as 500 errors. Errors outside of the MVC pipeline are still handled the way they have always been with ASP.NET. You turn on custom errors, specify error codes and paths to error pages, etc. It is important to remember that these will happen for anything and everything outside of what the HandleErrorAttribute handles. Also, these will happen whenever an error is not handled with the HandleErrorAttribute from inside of the pipeline. <system.web>  <customErrors mode="On" defaultRedirect="~/error">     <error statusCode="404" redirect="~/error/notfound"></error>  </customErrors>Sample Controllers public class ExampleController : Controller {     public ActionResult Exception()     {         throw new ArgumentNullException();     }     public ActionResult Db()     {         // Inherits from DbException         throw new MyDbException();     } } public class ErrorController : Controller {     public ActionResult Index()     {         return View();     }     public ActionResult NotFound()     {         return View();     } } Putting It All Together If we have all the code above included in our MVC 3 project, here is how the following scenario's will play out: 1.       A controller action throws an Exception. You will remain on the current page and the global HandleErrorAttributes will render the Error view. 2.       A controller action throws any type of DbException. You will remain on the current page and the global HandleErrorAttributes will render the DbError view. 3.       Go to a non-existent page. You will be redirect to the Error controller's NotFound action by the CustomErrors configuration for HTTP StatusCode 404. But don't take my word for it, download the sample project and try it yourself. Three Important Lessons Learned For the most part this is all pretty straight forward, but there are a few gotcha's that you should remember to watch out for: 1) Error views have models, but they must be of type HandleErrorInfo. It is confusing at first to think that you can't control the M in an MVC page, but it's for a good reason. Errors can come from any action in any controller, and no redirect is taking place, so the view engine is just going to render an error view with the only data it has: The HandleError Info model. Do not try to set the model on your error page or pass in a different object through a controller action, it will just blow up and cause a second exception after your first exception! 2) When the HandleErrorAttribute renders a page, it does not pass through a controller or an action. The standard web.config CustomErrors literally redirect a failed request to a new page. The HandleErrorAttribute is just rendering a view, so it is not going to pass through a controller action. But that's ok! Remember, a controller's job is to get the model for a view, but an error already has a model ready to give to the view, thus there is no need to pass through a controller. That being said, the normal ASP.NET custom errors still need to route through controllers. So if you want to share an error page between the HandleErrorAttribute and your web.config redirects, you will need to create a controller action and route for it. But then when you render that error view from your action, you can only use the HandlerErrorInfo model or ViewData dictionary to populate your page. 3) The HandleErrorAttribute obeys if CustomErrors are on or off, but does not use their redirects. If you turn CustomErrors off in your web.config, the HandleErrorAttributes will stop handling errors. However, that is the only configuration these two mechanisms share. The HandleErrorAttribute will not use your defaultRedirect property, or any other errors registered with customer errors. In Summary The HandleErrorAttribute is for displaying 500 errors that were caused by exceptions inside of the MVC pipeline. The custom errors are for redirecting from error pages caused by other HTTP codes.

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• How to ensure custom serverListener events fires before action events

  - by frank.nimphius

  Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman","serif";} Using JavaScript in ADF Faces you can queue custom events defined by an af:serverListener tag. If the custom event however is queued from an af:clientListener on a command component, then the command component's action and action listener methods fire before the queued custom event. If you have a use case, for example in combination with client side integration of 3rd party technologies like HTML, Applets or similar, then you want to change the order of execution. The way to change the execution order is to invoke the command item action from the client event method that handles the custom event propagated by the af:serverListener tag. The following four steps ensure your successful doing this 1.       Call cancel() on the event object passed to the client JavaScript function invoked by the af:clientListener tag 2.       Call the custom event as an immediate action by setting the last argument in the custom event call to true function invokeCustomEvent(evt){   evt.cancel();          var custEvent = new AdfCustomEvent(                         evt.getSource(),                         "mycustomevent",                                                                                                                    {message:"Hello World"},                         true);    custEvent.queue(); } 3.       When handling the custom event on the server, lookup the command item, for example a button, to queue its action event. This way you simulate a user clicking the button. Use the following code ActionEvent event = new ActionEvent(component); event.setPhaseId(PhaseId.INVOKE_APPLICATION); event.queue(); The component reference needs to be changed with the handle to the command item which action method you want to execute. 4.       If the command component has behavior tags, like af:fileDownloadActionListener, or af:setPropertyListener, defined, then these are also executed when the action event is queued. However, behavior tags, like the file download action listener, may require a full page refresh to be issued to work, in which case the custom event cannot be issued as a partial refresh. File download action tag: http://download.oracle.com/docs/cd/E17904_01/apirefs.1111/e12419/tagdoc/af_fileDownloadActionListener.html " Since file downloads must be processed with an ordinary request - not XMLHttp AJAX requests - this tag forces partialSubmit to be false on the parent component, if it supports that attribute." To issue a custom event as a non-partial submit, the previously shown sample code would need to be changed as shown below function invokeCustomEvent(evt){   evt.cancel();          var custEvent = new AdfCustomEvent(                         evt.getSource(),                         "mycustomevent",                                                                                                                    {message:"Hello World"},                         true);    custEvent.queue(false); } To learn more about custom events and the af:serverListener, please refer to the tag documentation: http://download.oracle.com/docs/cd/E17904_01/apirefs.1111/e12419/tagdoc/af_serverListener.html

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• How To: Using spatial data with Entity Framework and Connector/Net

  - by GABMARTINEZ

  One of the new features introduced in Entity Framework 5.0 is the incorporation of some new types of data within an Entity Data Model: the spatial data types. These types allow us to perform operations on coordinates values in an easier way. There's no need to add stored routines or functions for every operation among these geometry types, now the user can have the alternative to put this logic on his application or keep it in the database. In the new 6.7.4 version there's also this new feature incorporated to Connector/Net library so our users can start exploring it and could provide us some feedback or comments about this new functionality. Through this tutorial on how to create a Code First Entity Model with a geometry column, we'll show an example on using Geometry types and some common operations when using geometry types inside an application. Requirements: - Connector/Net 6.7.4 - Entity Framework 5.0 version - .NET Framework 4.5 version - Basic understanding on Entity Framework and C# language. - An installed and running instance of MySQL Server 5.5.x or 5.6.10 version- Visual Studio 2012. Step One: Create a new Console Application  Inside Visual Studio select File->New Project menu option and select the Console Application template. Also make sure the .Net 4.5 version is selected so the new features for EF 5.0 will work with the application. Step Two: Add the Entity Framework Package For adding the Entity Framework Package there is more than one option: the package manager console or the Manage Nuget Packages option dialog. If you want to open the Package Manager Console, go to the Tools Menu -> Library Package Manager -> Package Manager Console. On the Package Manager Console Type:Install-Package EntityFrameworkThis will add the reference to the project of the latest released No alpha version of Entity Framework. Step Three: Adding Entity class and DBContext We'll add a simple class that represents a table entity to save some places and its location using a DBGeometry column that will be mapped to a Geometry type in MySQL. After that some operations can be performed using this data. public class MyPlace { [Key] public int Id { get; set; } public string name { get; set; } public DbGeometry location { get; set; } } public class JourneyDb : DbContext { public DbSet<MyPlace> MyPlaces { get; set; } }  Also make sure to add the connection string to the App.Config file as in the example: <?xml version="1.0" encoding="utf-8"?> <configuration>   <configSections>     <!-- For more information on Entity Framework configuration, visit http://go.microsoft.com/fwlink/?LinkID=237468 -->     <section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=5.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" />   </configSections>   <startup>     <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5" />   </startup>   <connectionStrings>     <add name="JourneyDb" connectionString="server=localhost;userid=root;pwd=;database=journeydb" providerName="MySql.Data.MySqlClient"/>   </connectionStrings>   <entityFramework>     </entityFramework> </configuration> Note also that the <entityFramework> section is empty.Step Four: Adding some new records.On the Program.cs file add the following code for the Main method so the Database gets created and also some new data can be added to the new table. This code adds some records containing some determinate locations. After being added a distance function will be used to know how much distance has each location in reference to the Queens Village Station in New York. static void Main(string[] args)    {     using (JourneyDb cxt = new JourneyDb())      {        cxt.Database.Delete();        cxt.Database.Create();         cxt.MyPlaces.Add(new MyPlace()        {          name = "JFK INTERNATIONAL AIRPORT OF NEW YORK",          location = DbGeometry.FromText("POINT(40.644047 -73.782291)"),        });         cxt.MyPlaces.Add(new MyPlace()        {          name = "ALLEY POND PARK",          location = DbGeometry.FromText("POINT(40.745696 -73.742638)"),        });       cxt.MyPlaces.Add(new MyPlace()        {          name = "CUNNINGHAM PARK",          location = DbGeometry.FromText("POINT(40.735031 -73.768387)"),        });         cxt.MyPlaces.Add(new MyPlace()        {          name = "QUEENS VILLAGE STATION",          location = DbGeometry.FromText("POINT(40.717957 -73.736501)"),        });         cxt.SaveChanges();         var points = (from p in cxt.MyPlaces                      select new { p.name, p.location });        foreach (var item in points)       {         Console.WriteLine("Location " + item.name + " has a distance in Km from Queens Village Station " + DbGeometry.FromText("POINT(40.717957 -73.736501)").Distance(item.location) * 100);       }       Console.ReadKey();      }  }}Output : Location JFK INTERNATIONAL AIRPORT OF NEW YORK has a distance from Queens Village Station 8.69448802402959 Km. Location ALLEY POND PARK has a distance from Queens Village Station 2.84097675104912 Km. Location CUNNINGHAM PARK has a distance from Queens Village Station 3.61695793727275 Km. Location QUEENS VILLAGE STATION has a distance from Queens Village Station 0 Km. Conclusion:Adding spatial data to a table is easier than before when having Entity Framework 5.0. This new Entity Framework feature that handles spatial data columns within the Data layer has a lot of integrated functions and methods toease this type of tasks.Notes:This version of Connector/Net is just released as GA so is preatty much stable to be used on a ProductionEnvironment. Please send us your comments or questions using this blog or at the Forums where we keep answering any questions you have about Connector/Net and MySQL Server.A copy of this sample project can be downloaded here. This application does not include any library so you will haveto add them before running it. Happly MySQL/.Net Coding.

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• Creating a Document Library with Content Type in code

  - by David Jacobus

  Originally posted on: http://geekswithblogs.net/djacobus/archive/2013/10/15/154360.aspxIn the past, I have shown how to create a list content type and add the content type to a list in code.  As a Developer, many of the artifacts which we create are widgets which have a List or Document Library as the back end.   We need to be able to create our applications (Web Part, etc.) without having the user involved except to enter the list item data.  Today, I will show you how to do the same with a document library.    A summary of what we will do is as follows:   1.   Create an Empty SharePoint Project in Visual Studio 2.   Add a Code Folder in the solution and Drag and Drop Utilities and Extensions Libraries to the solution 3.   Create a new Feature and add and event receiver  all the code will be in the event receiver 4.   Add the fields which will extend the built-in Document content type 5.   If the Content Type does not exist, Create it 6.   If the Document Library does not exist, Create it with the new Content Type inherited from the Document Content Type 7.   Delete the Document Content Type from the Library (as we have a new one which inherited from it) 8.   Add the fields which we want to be visible from the fields added to the new Content Type   Here we go:   Create an Empty SharePoint Project in Visual Studio      Add a Code Folder in the solution and Drag and Drop Utilities and Extensions Libraries to the solution       The Utilities and Extensions Library will be part of this project which I will provide a download link at the end of this post.  Drag and drop them into your project.  If Dragged and Dropped from windows explorer you will need to show all files and then include them in your project.  Change the Namespace to agree with your project.   Create a new Feature and add and event receiver  all the code will be in the event receiver.  Here We added a new Feature called “CreateDocLib”  and then right click to add an Event Receiver All of our code will be in this Event Receiver.  For this Demo I will only be using the Feature Activated Event.      From this point on we will be looking at code!    We are adding two constants for use columGroup (How we want SharePoint to Group them, usually Company Name) and ctName(ContentType Name)  using System; using System.Runtime.InteropServices; using System.Security.Permissions; using Microsoft.SharePoint; namespace CreateDocLib.Features.CreateDocLib { /// <summary> /// This class handles events raised during feature activation, deactivation, installation, uninstallation, and upgrade. /// </summary> /// <remarks> /// The GUID attached to this class may be used during packaging and should not be modified. /// </remarks> [Guid("56e6897c-97c4-41ac-bc5b-5cd2c04f2dd1")] public class CreateDocLibEventReceiver : SPFeatureReceiver { const string columnGroup = "DJ"; const string ctName = "DJDocLib"; } }     Here we are creating the Feature Activated event.   Adding the new fields (Site Columns) ,  Testing if the Content Type Exists, if not adding it.  Testing if the document Library exists, if not adding it.   #region DocLib public override void FeatureActivated(SPFeatureReceiverProperties properties) { using (SPWeb spWeb = properties.GetWeb() as SPWeb) { //add the fields addFields(spWeb); //add content type SPContentType testCT = spWeb.ContentTypes[ctName]; // we will not create the content type if it exists if (testCT == null) { //the content type does not exist add it addContentType(spWeb, ctName); } if ((spWeb.Lists.TryGetList("MyDocuments") == null)) { //create the list if it dosen't to exist CreateDocLib(spWeb); } } } #endregion The addFields method uses the utilities library to add site columns to the site. We can add as many fields within this method as we like. Here we are adding one for demonstration purposes. Icon as a Url type.  public void addFields(SPWeb spWeb) { Utilities.addField(spWeb, "Icon", SPFieldType.URL, false, columnGroup); }The addContentType method add the new Content Type to the site Content Types. We have already checked to see that it does not exist. In addition, here is where we add the linkages from our site columns previously created to our new Content Type   private static void addContentType(SPWeb spWeb, string name) { SPContentType myContentType = new SPContentType(spWeb.ContentTypes["Document"], spWeb.ContentTypes, name) { Group = columnGroup }; spWeb.ContentTypes.Add(myContentType); addContentTypeLinkages(spWeb, myContentType); myContentType.Update(); } Here we are adding just one linkage as we only have one additional field in our Content Type public static void addContentTypeLinkages(SPWeb spWeb, SPContentType ct) { Utilities.addContentTypeLink(spWeb, "Icon", ct); } Next we add the logic to create our new Document Library, which we have already checked to see if it exists.  We create the document library and turn on content types.  Add the new content type and then delete the old “Document” content types.   private void CreateDocLib(SPWeb web) { using (var site = new SPSite(web.Url)) { var web1 = site.RootWeb; var listId = web1.Lists.Add("MyDocuments", string.Empty, SPListTemplateType.DocumentLibrary); var lib = web1.Lists[listId] as SPDocumentLibrary; lib.ContentTypesEnabled = true; var docType = web.ContentTypes[ctName]; lib.ContentTypes.Add(docType); lib.ContentTypes.Delete(lib.ContentTypes["Document"].Id); lib.Update(); AddLibrarySettings(web1, lib); } }  Finally, we set some document library settings on our new document library with the AddLibrarySettings method. We then ensure that the new site column is visible when viewed in the browser.  private void AddLibrarySettings(SPWeb web, SPDocumentLibrary lib) { lib.OnQuickLaunch = true; lib.ForceCheckout = true; lib.EnableVersioning = true; lib.MajorVersionLimit = 5; lib.EnableMinorVersions = true; lib.MajorWithMinorVersionsLimit = 5; lib.Update(); var view = lib.DefaultView; view.ViewFields.Add("Icon"); view.Update(); } Okay, what's cool here: In a few lines of code, we have created site columns, A content Type, a document library. As a developer, I use this functionality all the time. For instance, I could now just add a web part to this same solutionwhich uses this document Library. I love SharePoint! Here is the complete solution: Create Document Library Code

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