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• Standard and reliable mouse-reporting with GLUT

  - by Victor

  Hello! I'm trying to use GLUT (freeglut) in my OpenGL application, and I need to register some callbacks for mouse wheel events. I managed to dig out a fairly undocumented function: api documentation But the man page and the API entry for this function both state the same thing: Note: Due to lack of information about the mouse, it is impossible to implement this correctly on X at this time. Use of this function limits the portability of your application. (This feature does work on X, just not reliably.) You are encouraged to use the standard, reliable mouse-button reporting, rather than wheel events. Fair enough, but how do I use this standard, reliable mouse-reporting? And how do I know which is the standard? Do I just use glutMouseFunc() and use button values like 4 and 5 for the scroll up and down values respectively, say if 1, 2 and 3 are the left, middle and right buttons? Is this the reliable method? Bonus question: it seems the `xev' tool is reporting different values for my buttons. My mouse buttons are numbered from 1 to 5 with xev, but glut is reporting buttons from 0 to 4, i.e. an off-by-one. Is this common?

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• implementing cryptographic algorithms, specifically the key expansion part

  - by masseyc

  Hey, recently I picked up a copy of Applied Cryptography by Bruce Schneier and it's been a good read. I now understand how several algorithms outlined in the book work, and I'd like to start implementing a few of them in C. One thing that many of the algorithms have in common is dividing an x-bit key, into several smaller y-bit keys. For example, blowfish's key, X, is 64-bits, but you are required to break it up into two 32-bit halves; Xl and Xr. This is where I'm getting stuck. I'm fairly decent with C, but I'm not the strongest when it comes to bitwise operators and the like. After some help on IRC, I managed to come up with these two macros: #define splitup(a, b, c) {b = a >> 32; c = a & 0xffffffff; } #define combine(a, b, c) {a = (c << 32) | a;} Where a is 64 bits and b and c are 32 bits. However, the compiler warns me about the fact that I'm shifting a 32 bit variable by 32 bits. My questions are these: what's bad about shifting a 32-bit variable 32 bits? I'm guessing it's undefined, but these macros do seem to be working. Also, would you suggest I go about this another way? As I said, I'm fairly familiar with C, but bitwise operators and the like still give me a headache.

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• [Database] How to model this one-to-one relation?

  - by pbean

  I have several entities which respresent different types of users who need to be able to log in to a particular system. Additionally, they have different types of information associated with them. For example: a "general user", which has an e-mail address and "admin user", which has a workstation number (note that this a hypothetical case). Both entities also share common properties like first name, surname, address and telephone number. Finally, they naturally need to have a (unique) user name and a password to log in. In the application, the user just has to fill in his user name and password, and the functionality of the application changes slightly according to the type of the user. You can imagine that the username needs to be unique for this work. How should I model this effectively? I can't just create two tables, because then I can't force a unique constaint on the user name. I also can't put them all in just one table, because they have different types of specific information associated to them. I think I might need 3 seperate tables, one for "users" (with user name and password), one for the "general users" and another one for the "admin users", but how would the relations between these work? Or is there another solution? (By the way, the target DBMS is MySQL, so I don't think generalization is supported in the database system itself).

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• Hibernate 3.5.0 causes extreme performance problems

  - by user303396

  I've recently updated from hibernate 3.3.1.GA to hibernate 3.5.0 and I'm having a lot of performance issues. As a test, I added around 8000 entities to my DB (which in turn cause other entities to be saved). These entities are saved in batches of 20 so that the transactions aren't too large for performance reasons. When using hibernate 3.3.1.GA all 8000 entities get saved in about 3 minutes. When using hibernate 3.5.0 it starts out slower than with hibernate 3.3.1. But it gets slower and slower. At around 4,000 entities, it sometimes takes 5 minutes just to save a batch of 20. If I then go to a mysql console and manually type in an insert statement from the mysql general query log, half of them run perfect in 0.00 seconds. And half of them take a long time (maybe 40 seconds) or timeout with "ERROR 1205 (HY000): Lock wait timeout exceeded; try restarting transaction" from MySQL. Has something changed in hibernate's transaction management in version 3.5.0 that I should be aware of? The ONLY thing I changed to experience these unusable performance issues is replace the following hibernate 3.3.1.GA jar files: com.springsource.org.hibernate-3.3.1.GA.jar, com.springsource.org.hibernate.annotations-3.4.0.GA.jar, com.springsource.org.hibernate.annotations.common-3.3.0.ga.jar, com.springsource.javassist-3.3.0.ga.jar with the new hibernate 3.5.0 release hibernate3.jar and javassist-3.9.0.GA.jar. Thanks.

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• Python optimization problem?

  - by user342079

  Alright, i had this homework recently (don't worry, i've already done it, but in c++) but I got curious how i could do it in python. The problem is about 2 light sources that emit light. I won't get into details tho. Here's the code (that I've managed to optimize a bit in the latter part): import math, array import numpy as np from PIL import Image size = (800,800) width, height = size s1x = width * 1./8 s1y = height * 1./8 s2x = width * 7./8 s2y = height * 7./8 r,g,b = (255,255,255) arr = np.zeros((width,height,3)) hy = math.hypot print 'computing distances (%s by %s)'%size, for i in xrange(width): if i%(width/10)==0: print i, if i%20==0: print '.', for j in xrange(height): d1 = hy(i-s1x,j-s1y) d2 = hy(i-s2x,j-s2y) arr[i][j] = abs(d1-d2) print '' arr2 = np.zeros((width,height,3),dtype="uint8") for ld in [200,116,100,84,68,52,36,20,8,4,2]: print 'now computing image for ld = '+str(ld) arr2 *= 0 arr2 += abs(arr%ld-ld/2)*(r,g,b)/(ld/2) print 'saving image...' ar2img = Image.fromarray(arr2) ar2img.save('ld'+str(ld).rjust(4,'0')+'.png') print 'saved as ld'+str(ld).rjust(4,'0')+'.png' I have managed to optimize most of it, but there's still a huge performance gap in the part with the 2 for-s, and I can't seem to think of a way to bypass that using common array operations... I'm open to suggestions :D

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• Visual Studio and .NET programming

  - by Vit

  Hi, I just want to ask wheather I am right or not about .NET. So, .NET is new framework that enables you to easily implement new and old windows functions. It is similiar to java in the way that its also compiled into "bytecode", but its name is Common Language Infrastructure, or CLI. This language is interpreted by .NET Framework, so code generated by programming using .NET cannot be executed directly by CPU. Now, few languages can be compiled to CLI. First, it was Microsoft-developed C#, than J#, C++ others. I suspect that this is in general right, at least I hope I understand it right. But, what I am still missing is, can you write to machine code compiled code in C#? And, if using Visual Studio 2005, when I select Win32 project, it is compiled into machine code, so only thing you need to run this apps are windows dynamic-link libraries, since static libraries code is implemented into app durink linking phase. And those dynamic-link libraries are implemented in every windows installation, or provided by DirectX installations. But when I select CLR in Visual Studio 2005, than app is compiled into CLI code, and it first executes .NET framework, and than .NET framework executes that program, since its not in machine code. So, I am right? I ask becouse you can read these infos on the internet, but I have noone to tell me wheather I understand it right or not. Thanks.

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• Is there a way to increase the efficiency of shared_ptr by storing the reference count inside the co

  - by BillyONeal

  Hello everyone :) This is becoming a common pattern in my code, for when I need to manage an object that needs to be noncopyable because either A. it is "heavy" or B. it is an operating system resource, such as a critical section: class Resource; class Implementation : public boost::noncopyable { friend class Resource; HANDLE someData; Implementation(HANDLE input) : someData(input) {}; void SomeMethodThatActsOnHandle() { //Do stuff }; public: ~Implementation() { FreeHandle(someData) }; }; class Resource { boost::shared_ptr<Implementation> impl; public: Resource(int argA) explicit { HANDLE handle = SomeLegacyCApiThatMakesSomething(argA); if (handle == INVALID_HANDLE_VALUE) throw SomeTypeOfException(); impl.reset(new Implementation(handle)); }; void SomeMethodThatActsOnTheResource() { impl->SomeMethodThatActsOnTheHandle(); }; }; This way, shared_ptr takes care of the reference counting headaches, allowing Resource to be copyable, even though the underlying handle should only be closed once all references to it are destroyed. However, it seems like we could save the overhead of allocating shared_ptr's reference counts and such separately if we could move that data inside Implementation somehow, like boost's intrusive containers do. If this is making the premature optimization hackles nag some people, I actually agree that I don't need this for my current project. But I'm curious if it is possible.

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• Achieving Thread-Safety

  - by Smasher

  Question How can I make sure my application is thread-safe? Are their any common practices, testing methods, things to avoid, things to look for? Background I'm currently developing a server application that performs a number of background tasks in different threads and communicates with clients using Indy (using another bunch of automatically generated threads for the communication). Since the application should be highly availabe, a program crash is a very bad thing and I want to make sure that the application is thread-safe. No matter what, from time to time I discover a piece of code that throws an exception that never occured before and in most cases I realize that it is some kind of synchronization bug, where I forgot to synchronize my objects properly. Hence my question concerning best practices, testing of thread-safety and things like that. mghie: Thanks for the answer! I should perhaps be a little bit more precise. Just to be clear, I know about the principles of multithreading, I use synchronization (monitors) throughout my program and I know how to differentiate threading problems from other implementation problems. But nevertheless, I keep forgetting to add proper synchronization from time to time. Just to give an example, I used the RTL sort function in my code. Looked something like FKeyList.Sort (CompareKeysFunc); Turns out, that I had to synchronize FKeyList while sorting. It just don't came to my mind when initially writing that simple line of code. It's these thins I wanna talk about. What are the places where one easily forgets to add synchronization code? How do YOU make sure that you added sync code in all important places?

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• Returning HTML in the JS portion of a respond_to block throws errors in IE

  - by Horace Loeb

  Here's a common pattern in my controller actions: respond_to do |format| format.html {} format.js { render :layout => false } end I.e., if the request is non-AJAX, I'll send the HTML content in a layout on a brand new page. If the request is AJAX, I'll send down the same content, but without a layout (so that it can be inserted into the existing page or put into a lightbox or whatever). So I'm always returning HTML in the format.js portion, yet Rails sets the Content-Type response header to text/javascript. This causes IE to throw this fun little error message: Of course I could set the content-type of the response every time I did this (or use an after_filter or whatever), but it seems like I'm trying to do something relatively standard and I don't want to add additional boilerplate code. How do I fix this problem? Alternatively, if the only way to fix the problem is to change the content-type of the response, what's the best way to achieve the behavior I want (i.e., sending down content with layout for non-AJAX and the same content without a layout for AJAX) without having to deal with these errors? Edit: This blog post has some more info

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• Best practice to test a web application, regarding domain name and integration with external service

  - by ycseattle

  I have run into these problems several times and was never able to find a comfortable solution. Let's say my website has the domain name MyDomain.com. When I run the tests on the test machine (a continuous integration server), I will modify the HOSTS file on this machine so the MyDomain.com is mapped to this local machine instead of the real production server. This doesn't work very well for many situations. For example, my application will create subdomain names user1.MyDomain.com dynamically but this is difficult to keep the testing flexible. Another problem is my web application will interact with Amazon S3, and sometimes other service like Amazon Simple Message Queue. I am only comfortable to include these interaction in my tests but I am never happy with my solution for mixing testing and production on Amazon services. Could somebody offer some tips on these issues? I would like to make my testing framework clean and flexible. I am sure this is a common question for all web applications and there must be a mature way to deal with these. Thanks!

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• Web Hosting: Any web host that supports files more than 50,000 in number?

  - by Devner

  Hi all, For my PHP & mySQL based application, I am trying to buy website hosting from a host who does not have a limit on the number of files I carry in my hosting account. Almost all the websites have a common limit of 50,000 files (some websites call it 50,000 nodes). The rest(to the extent of my search) are not even close. I have gone through the various websites, Googled lot of information, have spoken with the customer service of the hosting companies and they said that they have a limit of 50,000 files and that's why they call it the LIMIT. Now I have my application, which is a kind of social networking website, where people can upload various files of varying file size. So say if 50,000 users were to join the website and upload 1 file each, the limit of 50,000 will be reached very easily and my 50,001 customer will start facing file upload problems (& so will my account). So I would like to know if there's any website hosting services that do NOT levy such restrictions. In summary, I need the following options: No maximum file limit (more than 50,000 files in account). No maximum file upload limit in server setting (10MB, 12MB, 15MB, 20MB, etc.). Ability to upload files of various types (zip, flv, jg, png, etc.). Ability to stream Audio and Video (live audio & video not necessary). Access to .htaccess Access to php.ini, my.cnf or my.ini (this would be a plus) Supports SSL. Provides dedicated hosting(& IP) as well. Monthly payments without contracts are a plus. If you know of any such website hosting services, please post a reply ( a link to the same will be appreciated ). Thank you.

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• What is the process involved in viewing a webservice in a browser from within visual studio?

  - by Sam Holder

  I have created a new VS2008 ASP.Net Web service project, with the default name WebService1. If I right click on the Service1.asmx file and select 'View in Browser' what are the processes that go on to make this happen? I am asking because I have a situation where when I run this from a visual studio project started in our development shell (which sets up a common build environment) I cannot get the web service to show up in the browser. It starts the asp.net development server and creates a single file: C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\Temporary ASP.NET Files\root\c43ddc22\268ae91b\hash\hash.web but when I start it from a stand alone project i get a whole slew of files in here: C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\Temporary ASP.NET Files\root\edad4eee\d198cf0e\App_Web_defaultwsdlhelpgenerator.aspx.cdcab7d2.vicgkf94.dll C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\Temporary ASP.NET Files\root\edad4eee\d198cf0e\service1.asmx.cdcab7d2.compiled etc etc I am trying to debug this but not really getting anywhere. i have inspected the output from VS but the only option I get is for the build output, which is basic and doesn't really contain any information that is useful. I have tried running both versions with DebugView running but no output there either. I would like to know if there are any log files I could look at, or if anyone has any suggestions on how I might be able to debug what is going wrong here? For completeness the output I get when it doesn't work is: Parser Error Description: An error occurred during the parsing of a resource required to service this request. Please review the following specific parse error details and modify your source file appropriately. Parser Error Message: Could not create type 'WebService1.Service1'. Source Error: Line 1: Source File: /Service1.asmx Line: 1 Version Information: Microsoft .NET Framework Version:2.0.50727.3603; ASP.NET Version:2.0.50727.3082

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• How to keep confirmation messages after POST while doing a post-submit redirect?

  - by MicE

  Hello, I'm looking for advise on how to share certain bits of data (i.e. post-submit confirmation messages) between individual requests in a web application. Let me explain: Current approach: user submits an add/edit form for a resource if there were no errors, user is shown a confirmation with links to: submit a new resource (for "add" form) view the submitted/edited resource view all resources (one step above in hierarchy) user then has to click on one of the three links to proceed (i.e. to the page "above") Progmatically, the form and its confirmation page are one set of classes. The page above that is another. They can technically share code, but at the moment they are both independent during processing of individual requests. We would like to amend the above as follows: user submits an add/edit form for a resource if there were no errors, the user is redirected to the page with all resources (one step above in hierarchy) with one or more confirmation messages displayed at the top of the page (i.e. success message, to whom was the request assigned, etc) This will: save users one click (they have to go through a lot of these add/edit forms) the post-submit redirect will address common problems with browser refresh / back-buttons What approach would you recommend for sharing data needed for the confirmation messages between the two requests, please? I'm not sure if it helps, it's a PHP application backed by a RESTful API, but I think that this is a language-agnostic question. A few simple solutions that come to mind are to share the data via cookies or in the session, this however breaks statelessness and would pose a significant problem for users who work in several tabs (the data could clash together). Passing the data as GET parameters is not suitable as we are talking about several messages which are dynamic (e.g. changing actors, dates). Thanks, M.

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• Git. Checkout feature branch between merge commits

  - by mageslayer

  Hi all It's kind weird, but I can't fulfill a pretty common operation with git. Basically what I want is to checkout a feature branch, not using it's head but using SHA id. This SHA points between merges from master branch. The problem is that all I get is just master branch without a commits from feature branch. Currently I'm trying to fix a regression introduced earlier in master branch. Just to be more descriptive, I crafted a small bash script to recreate a problem repository: #!/bin/bash rm -rf ./.git git init echo "test1" > test1.txt git add test1.txt git commit -m "test1" -a git checkout -b patches master echo "test2" > test2.txt git add test2.txt git commit -m "test2" -a git checkout master echo "test3" > test3.txt git add test3.txt git commit -m "test3" -a echo "test4" > test4.txt git add test4.txt git commit -m "test4" -a echo "test5" > test5.txt git add test5.txt git commit -m "test5" -a git checkout patches git merge master #Now how to get a branch having all commits from patches + test3.txt + test4.txt - test5.txt ??? Basically all I want is just to checkout branch "patches" with files 1-4, but not including test5.txt. Doing: git checkout [sha_where_test4.txt_entered] ... just gives a branch with test1,test3,test4, but excluding test2.txt Thanks.

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• What are the lengths/limits C preprocessor as a language creation tool? Where can I learn more about

  - by Weston C

  In his FAQ @ http://www2.research.att.com/~bs/bs_faq.html#bootstrapping, Bjarne Stroustrup says: To build [Cfront, the first C++ compiler], I first used C to write a "C with Classes"-to-C preprocessor. "C with Classes" was a C dialect that became the immediate ancestor to C++... I then wrote the first version of Cfront in "C with Classes". When I read this, it piqued my interest in the C preprocessor. I'd seen its macro capabilities as suitable for simplifying common expressions but hadn't thought about its ability to significantly add to syntax and semantics on the level that I imagine bringing classes to C took. So now I have a couple of questions on my mind: 1) Are there other examples of this approach to bootstrapping a language off of C? 2) Is the source to Stroustrup's original work available anywhere? 3) Where could I learn more about the specifics of utilizing this technique? 4) What are the lengths/limits of that approach? Could one, say, create a set of preprocessor macros that let someone write in something significantly Lisp/Scheme like?

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• Keyboard shortcut to Un/Comment out code in Mathematica 7?

  - by dbjohn

  A keyboard shortcut to comment/uncomment out a piece of code is common in other programming IDE's for languages like Java, .Net. I find it a very useful technique when experimenting through trial and error to temporarily comment out and uncomment lines, words and parts of the code to find out what is and isn't working. I cannot find any such keyboard shortcut on the Mathematica front end in version 7. I know that it is possible to comment out code by selecting the code, right mouse click and select Un/Comment from the menu that appears but this is too slow while coding. I tried to access this using the menu key Menu on the keyboard but Mathematica frontend doesn't respond to or recognise this key unlike other applications, this could have allowed a key combination for commenting. Can someone else verify that this isn't unique to my machine and that the key isn't recognised by mathematica. I looked at this question and looked in the KeyEventTranslations.tr file but I don't think there is any way to create a shortcut to do this(?). Should I just live with it? Any other suggestions? (I have seen there is an Emacs version of mathematica, I have never tried Emacs or this Mma version and imagine that it would have this ability but would prefer not to go to the trouble and uncertainty of installing it. Also I would guess that the Wolfram Workbench could do this, but that may not be worth the investment just for this.)

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• Centralized Exception handling for Eclipse plug-in

  - by Svilen

  Hello, At first I thought this would be question often asked, however trying (and failing) to look up info on this proved me wrong. Is there a mechanism in Eclipse platform for centralized exception handling of exceptions? For example... You have plug-in project which connects to a DB and issues queries, results of which are used to populate some e.g. views. This is like the most common example ever. :) Queries are executed almost for any user action, from every UI control the plug-in provides. Most likely the DB Query API will have some specific to the DB SomeDBGeneralException declared as being thrown by it. That's OK, you can handle those according to whatever your software design is. But how about unchecked exceptions which are likely to occur, e.g. , when communication with DB suddenly breaks for some network related reason? What if in such case one would like to catch those exceptions in a central place and for example provide user friendly message to the user (rather than the low level communication protocol api messages) and even some possible actions the user could execute in order to deal with the specific problem? Thinking in Eclipse platform context, the question may be rephrased as "Is there an extension point like "org.eclipse.ExceptionHandler" which allows to declare exception handlers for specific (some kind of filtering support) exceptions giving a lot of flexibility with the actual handling?"

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• Schema for element with Attributes and Child nodes

  - by Matthew

  I am trying to write xsd type schema for an element that has a custom type to include addition attributes to extend a base type. I am running into trouble getting the syntax right. <xs:element name="graphs"> <xs:complexType> <xs:sequence> <xs:element name="graph" minOccurs="1" maxOccurs="unbounded" type="graphType"> <!-- child elements --> </xs:element> </xs:sequence> </xs:complexType> </xs:element> <xs:complexType name="graphType"> <xs:simpleContent> <xs:extension base="xs:string"> <xs:attribute name="title" type="xs:string"/> <xs:attribute name="type" type="xs:string"/> </xs:extension> </xs:simpleContent> </xs:complexType> I thought this would be something very common, but having read many tuts and forums, I cant seem to find an answer that works for me.

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• Export GridView to Excel (not working)

  - by Chiramisu

  I've spent the last two days trying to get some bloody data to export to Excel. After much research I determined that the best and most common way is using HttpResponse headers as shown in my code below. After stepping through countless times in debug mode, I have confirmed that the data is in fact there and both filtered and sorted the way I want it. However, it does not download as an Excel file, or do anything at all for that matter. I suspect this may have something to do with my UpdatePanel or perhaps the ImageButton not posting back properly, but I'm not sure. What am I doing wrong? Please help me to debug this issue. I will be eternally grateful. Thank you. :) Markup <asp:UpdatePanel ID="statusUpdatePanel" runat="server" UpdateMode="Conditional"> <Triggers> <asp:AsyncPostBackTrigger ControlID="btnExportXLS" EventName="Click" /> </Triggers> <ContentTemplate> <asp:GridView ID="GridView1" runat="server" AllowPaging="True" PageSize="10" AllowSorting="True" DataSourceID="GridView1SDS" DataKeyNames="ID"> </asp:GridView> <span><asp:ImageButton ID="btnExportXLS" runat="server" /></span> </ContentTemplate> </asp:UpdatePanel> Codebehind Protected Sub ExportToExcel() Handles btnExportXLS.Click Dim dt As New DataTable() Dim da As New SqlDataAdapter(SelectCommand, ConnectionString) da.Fill(dt) Dim gv As New GridView() gv.DataSource = dt gv.DataBind() Dim frm As HtmlForm = New HtmlForm() frm.Controls.Add(gv) Dim sw As New IO.StringWriter() Dim hw As New System.Web.UI.HtmlTextWriter(sw) Response.ContentType = "application/vnd.ms-excel" Response.AddHeader("content-disposition", "attachment;filename=Report.xls") Response.Charset = String.Empty gv.RenderControl(hw) Response.Write(sw.ToString()) Response.End() End Sub

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• What exactly is a reentrant function?

  - by eSKay

  Most of the times, the definition of reentrance is quoted from Wikipedia: A computer program or routine is described as reentrant if it can be safely called again before its previous invocation has been completed (i.e it can be safely executed concurrently). To be reentrant, a computer program or routine: Must hold no static (or global) non-constant data. Must not return the address to static (or global) non-constant data. Must work only on the data provided to it by the caller. Must not rely on locks to singleton resources. Must not modify its own code (unless executing in its own unique thread storage) Must not call non-reentrant computer programs or routines. How is safely defined? If a program can be safely executed concurrently, does it always mean that it is reentrant? What exactly is the common thread between the six points mentioned that I should keep in mind while checking my code for reentrant capabilities? Also, Are all recursive functions reentrant? Are all thread-safe functions reentrant? Are all recursive and thread-safe functions reentrant? While writing this question, one thing comes to mind: Are the terms like reentrance and thread safety absolute at all i.e. do they have fixed concrete definations? For, if they are not, this question is not very meaningful. Thanks!

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• A question about entities, roles and interfaces in Entity Framework 4.

  - by mvole

  Hi, I am an experienced .NET developer but new to EF - so please bear with me. I will use an example of a college application to illustrate my problem. I have these user roles: Lecturer, Student, Administrator. In my code I envisage working with these entities as distinct classes so e.g. a Lecturer teaches a collection of Students. And work with 'is Student' 'TypeOf' etc. Each of these entities share lots of common properties/methods e.g. they can all log onto the system and do stuff related to their role. In EF designer I can create a base entity Person (or User...) and have Lecturer, Student and Administrator all inherit from that. The difficulty I have is that a Lecturer can be an Administrator - and in fact on occasion a Student can be a Lecturer. If I were to add other entities such as Employee and Warden then this gets even more of an issue. I could presumably work with Interfaces so a person could implement ILecturer and IStudent, however I do not see how this fits within EF. I would like to work within the EF designer if possible and I'm working model-first (coding in C#). So any help and advice/samples would be very welcome and much appreciated. Thanks

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• How do I search & replace all occurrences of a string in a ms word doc with python?

  - by Mark

  Hello there, I am pretty stumped at the moment. Based on http://stackoverflow.com/questions/1045628/can-i-use-win32-com-to-replace-text-inside-a-word-document I was able to code a simple template system that generates word docs out of a template word doc (in Python). My problem is that text in "Text Fields" is not find that way. Even in Word itself there is no option to search everything - you actually have to choose between "Main Document" and "Text Fields". Being new to the Windows world I tried to browse the VBA docs for it but found no help (probably due to "text field" being a very common term). word.Documents.Open(f) wdFindContinue = 1 wdReplaceAll = 2 find_str = '\{\{(*)\}\}' find = word.Selection.Find find.Execute(find_str, False, False, True, False, False, \ True, wdFindContinue, False, False, False) while find.Found: t = word.Selection.Text.__str__() r = process_placeholder(t, answer_data, question_data) if type(r) == dict: errors.append(r) else: find.Execute(t, False, True, False, False, False, \ True, False, False, r, wdReplaceAll) This is the relevant portion of my code. I was able to get around all problems by myself by now (hint: if you want to replace strings with more than 256 chars, you have to do it via clipboard, etc ...) Hope, someone can help me.

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• Is it a good idea to use an integer column for storing US ZIP codes in a database?

  - by Yadyn

  From first glance, it would appear I have two basic choices for storing ZIP codes in a database table: Text (probably most common), i.e. char(5) or varchar(9) to support +4 extension Numeric, i.e. 32-bit integer Both would satisfy the requirements of the data, if we assume that there are no international concerns. In the past we've generally just gone the text route, but I was wondering if anyone does the opposite? Just from brief comparison it looks like the integer method has two clear advantages: It is, by means of its nature, automatically limited to numerics only (whereas without validation the text style could store letters and such which are not, to my knowledge, ever valid in a ZIP code). This doesn't mean we could/would/should forgo validating user input as normal, though! It takes less space, being 4 bytes (which should be plenty even for 9-digit ZIP codes) instead of 5 or 9 bytes. Also, it seems like it wouldn't hurt display output much. It is trivial to slap a ToString() on a numeric value, use simple string manipulation to insert a hyphen or space or whatever for the +4 extension, and use string formatting to restore leading zeroes. Is there anything that would discourage using int as a datatype for US-only ZIP codes?

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• Threadsafe way of exposing keySet()

  - by Jake

  This must be a fairly common occurrence where I have a map and wish to thread-safely expose its key set: public MyClass { Map<String,String> map = // ... public final Set<String> keys() { // returns key set } } Now, if my "map" is not thread-safe, this is not safe: public final Set<String> keys() { return map.keySet(); } And neither is: public final Set<String> keys() { return Collections.unmodifiableSet(map.keySet()); } So I need to create a copy, such as: public final Set<String> keys() { return new HashSet(map.keySet()); } However, this doesn't seem safe either because that constructor traverses the elements of the parameter and add()s them. So while this copying is going on, a ConcurrentModificationException can happen. So then: public final Set<String> keys() { synchronized(map) { return new HashSet(map.keySet()); } } seems like the solution. Does this look right?

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• Doing without partial commits the "Mercurial way"

  - by David Moles

  Subversion shop considering switching to Mercurial, trying to figure out in advance what all the complaints from developers are going to be. There's one fairly common use case here that I can't see how to handle. I'm working on some largish feature, and I have a significant part of the code -- or possibly several significant parts of the code -- in pieces all over the garage floor, totally unsuitable for checkin, maybe not even compiling. An urgent bugfix request comes in. The fix is nice and local and doesn't touch any of the code I've been working on. I make the fix in my working copy. Now what? I've looked at "Mercurial cherry picking changes for commit" and "best practices in mercurial: branch vs. clone, and partial merges?" and all the suggestions seem to be extensions of varying complexity, from Record and Shelve to Queues. The fact that there apparently isn't any core functionality for this makes me suspect that in some sense this working style is Doing It Wrong. What would a Mercurial-like solution to this use case look like?

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