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• Ubuntu won't start

  - by Tomas

  I've had Ubuntu installed, using WUBI, for some time now - a few months or so. It's worked fine until now, allowing me to login, use it's features etc... Two days ago, I turned on my computer and started Ubuntu. It loaded the GUI fine but just showed the loading screen and even after waiting 10 mins on this screen it still wouldn't show me the login page. I am enthusiastic about web design and development and all of my work, along with my portfolio is stored in Ubuntu. Cheers, Tomas EDIT: I am using 12.04 LTS.

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• Updated the Whiteboard Demo

  - by Bobby Diaz

  Just a quick update to let everyone know that I have updated the Whiteboard demo application.  I added a few options to make it more interesting to use!  I showed it to the kids and they loved it (even though they kept asking ME to draw pictures for them)!   Here is a list of available options: Color Picker for line color Slider for line thickness Save to XML file Open saved drawing Clear whiteboard Hold down ESC key to erase And here is a screenshot of my beautiful artwork! :) So what are you waiting for?  Go play with the Live Demo (and be sure to share with the kids) or download the source code. Enjoy!

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• what is need for a handler in general

  - by nish

  I have been searching for a definition for handler. basics i've understood that "A handler is a piece of code that is called when something happens, and usually takes some action, like generating a response." - (from http://stackoverflow.com/questions/3246200/what-is-an-handler ). But that can be a trigger or a callback. Also in specific an event handler on a low-level , often works by polling a device and waiting for a hardware response. So, what is the specific role of a handler ( that makes it unique from a trigger or a callback or any other such function ). Do all handlers have similar role ( event handler, file handler , exception handler, error handler )...

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• Exalogic Echo release available by Qualogy

  - by JuergenKress

  Just a quick post : there are new Exalogic goodies on Oracle E-Delivery today. Something we have been eagerly waiting for since the spring. Exalogic Stack version 2.0.6.0.0 (dubbed “Echo release”) is now available for download on E-Delivery (as demonstrated in the screenprints below). This is the third release of the “Exalogic virtual datacenter stack”. When more information is published about feature additions, improvements and bugfixes in this new release of the Exalogic virtual datacenter I will let you know! Read the full article here. WebLogic Partner Community For regular information become a member in the WebLogic Partner Community please visit: http://www.oracle.com/partners/goto/wls-emea ( OPN account required). If you need support with your account please contact the Oracle Partner Business Center. Blog Twitter LinkedIn Mix Forum Wiki Technorati Tags: Exalogic,Qualogy,WebLogic,WebLogic Community,Oracle,OPN,Jürgen Kress

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• Generate Multiple Choice Questions [closed]

  - by Daniel

  I'm working on a quiz application that will have a number of multiple choice questions. I'm waiting on the content from the client, but I'm hoping to start testing with some placeholder data for the time being. In order for the tests to be worthwhile, I probably need at least 100 multiple choice questions. I wanted to see if anyone knows of a resource or tool that can generate questions/multiple choice answers or propose another creative way to fill my quiz application with placeholder content. Ultimately the data will be in a MySQL database, but I don't really care what format the sample data is in (Excel, Word, JSON, etc.).

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• Friday Fun: The Rise of Atlantis

  - by Asian Angel

  The best day of the work week is finally here, so take a few minutes to have some fun while waiting to go home. In this week’s game you set off on a campaign across ancient Mediterranean regions to acquire multiple artifacts in a quest for success. Special Note: This flash version of the game allows you to play through three areas (Phoenicia, Babylon, and Egypt) of the overall campaign that is available in the full version. Even in its limited form it still provides a good amount of game play. How to See What Web Sites Your Computer is Secretly Connecting To HTG Explains: When Do You Need to Update Your Drivers? How to Make the Kindle Fire Silk Browser *Actually* Fast!

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• Would you make your website's source code public?

  - by Karpie

  Back story: My best friend is a self-taught coder for a community art site, written in PHP. Some time ago he mentioned he wanted to make the source code of the site public, to which my response was total horror - surely it was going to be full of security holes waiting to be found, and it was going to lead to hacking and errors on a huge scale. He never ended up doing it. Current story: I'm starting development of a community website built in Rails, and for ease of use I was going to use Github for version control. Then I realized it was pretty much exactly the same thing as my friend making his source code public - which made me stop and think. Would you make your website's completely-custom source code public? Or is this a case of open source gone too far? (note: I don't think this applies to people who run things like Wordpress. Or does it?)

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• Ubuntu 12.10 64bit fresh install, wireless issue!

  - by Dave

  Just installed a fresh Ubuntu 12.10 64bit on my laptop, run the update manager, restarted and suddenly I can't use my wifi anymore. Ubuntu software center installed automatically the wifi additional driver as you can see in my screenshot. If I mark the option "Do not use the device" and apply changes, restarting Ubuntu my wifi is back and I can use it. If I run iwconfig my terminal is showing this Now if I use Ubuntu for more than 20 minutes surfing the web my wifi it keeps to be connected but I don't receive any signal from it. Any page I try to open it simply don't open (just waiting icon). If I disconnect my wifi and connect it again, same issue, it doesn't work. The only way to make it work again is to restart Ubuntu. And the same story it happens again after aprox. 20, 30 minutes. WIFI device details: 03:00.0 Network controller [0280]: Broadcom Corporation BCM4313 802.11b/g/n Wireless LAN Controller [14e4:4727] (rev 01) Thanks, Dave

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• Why should most logic be in the monitor objects and not in the thread objects when writing concurrent software in Java?

  - by refuser

  When I took the Realtime and Concurrent programming course our lecturer told us that when writing concurrent programs in Java and using monitors, most of the logic should be in the monitor and as little as possible in the threads that access it. I never really understood why and I really would like to. Let me clarify. In this particular case we had several classes. Lift extends Thread Person extends Thread LiftView Monitor, all methods synchronized. This is nothing we came up with, our task was to implement a lift simulation with persons waiting on different floors, and theses were the class skeletons that were given. Then our lecturer said to implement most of the logic in the monitor (he was talking about class Monitor as THE monitor) and as little as possible in the threads. Why would he make a statement like that?

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• What happens at control invoke function?

  - by user65909

  A question about form controls invoke function. Control1 is created on thread1. If you want to update something in Control1 from thread2 you must do something like: delegate void SetTextCallback(string txt); void setText(string txt) { if (this.textBox1.InvokeRequired) { SetTextCallback d = new SetTextCallback(setText); this.Invoke(d, new object[] { txt }); } else { // this will run on thread1 even when called from thread2 this.textBox1.AppendText(msg); } }` What happens behind the scenes here? This invoke behaves different from a normal object invoke. When you want to call a function in an object on a specific thread, then that thread must be waiting on some queue of delegates, and execute the incoming delegates. Is it correct that the windows forms control invoke function is completely different from the standard object invoke function?

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• Multilevel Queue Scheduling (MQS) with Round Robin

  - by stackuser

  I'm trying to use MQS to create a Gantt chart of 5 processes (P1-P5) as well as their waiting, response, and turnaround times (and averages of those metrics) within a CPU task schedule. Here's the basic table of arrival times and bursts: Here's my actual work version after ticking off the finished processes. The time quantum for each time slice is (2 queues) TQ1=4 and TQ2=3. Note that I'm doing MQS and NOT MLFQ: It just doesn't feel like I'm doing MQS right here, I know this gets a little complex but maybe someone can point out where I'm going totally wrong.

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• 301 redirecting a blog's RSS feed URL?

  - by Marc Charbonneau

  I moved my personal blog from Wordpress to Ghost this weekend, which changes the RSS feed URL from /feed/ to /rss/. By default Ghost returns a 301 redirect for /feed/, which I've verified by checking the response header and looking at the logs: In Feedly though, new posts aren't being picked up (at least after 24 hours. I'm not sure if they might have a waiting period before updating the URL). What's the correct thing to do in this situation? Do I need to keep /feed/ alive instead of returning a 301? If so, is there a rewrite rule that would let me do this in nginx instead of having to modify the Ghost source code?

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• Naming a predicate: "precondition" or "precondition_is_met"?

  - by RexE

  In my web app framework, each page can have a precondition that needs to be satisfied before it can be displayed to the user. For example, if user 1 and user 2 are playing a back-and-forth role-playing game, user 2 needs to wait for user 1 to finish his turn before he can take his turn. Otherwise, the user is displayed a waiting page. This is implemented with a predicate: def precondition(self): return user_1.completed_turn The simplest name for this API is precondition, but this leads to code like if precondition(): ..., which is not really obvious. Seems to me like it is more accurate to call it precondition_is_met(), but not sure about that either. Is there a best practice for naming methods like this?

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• Windows Azure Tools for Microsoft Visual Studio 1.2 (June 2010)

  - by Eric Nelson

  Yey – we have a public release of the Windows Azure Tools which fully supports Visual Studio 2010 RTM and the .NET 4 Framework. And the biggy I have been waiting for – IntelliTrace support to debug your cloud deployed services (Requires  VS2010 Ultimate) Download today http://bit.ly/azuretoolsjune New for version 1.2: Visual Studio 2010 RTM Support: Full support for Visual Studio 2010 RTM. .NET 4 support: Choose to build services targeting either the .NET 3.5 or .NET 4 framework. Cloud storage explorer: Displays a read-only view of Windows Azure tables and blob containers through Server Explorer. Integrated deployment: Deploy services directly from Visual Studio by selecting ‘Publish’ from Solution Explorer. Service monitoring: Keep track of the state of your services through the ‘compute’ node in Server Explorer. IntelliTrace support for services running in the cloud: Adds support for debugging services in the cloud by using the Visual Studio 2010 IntelliTrace feature. This is enabled by using the deployment feature, and logs are retrieved through Server Explorer. Related Links: http://ukazure.ning.com for UK fans of Windows Azure IntelliTrace explained

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• Printer State: Idle - /usr/lib/cups/backend/dnssd failed

  - by bilbo88

  A printer was installed and worked but does not now. A job is successfully submitted, but keeps waiting there for printing (as seen from lpq command). Ping to printer works fine. (The printer is on and works as it prints from Windows.) But on the Printer Property, it shows Printer State: Idle - /usr/lib/cups/backend/dnssd failed. The following command does not help either. sudo service avahi-daemon restart Does any one has a solution? Thank you for help.

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• Why is implementing copy-paste in a touch screen based smartphone such a big deal?

  - by EpsilonVector

  I'm not entirely sure this is on-topic, but it definitely needs a programmer's understanding to be answered, and deals with general development (for a specific scenario) as opposed to a specific piece of code. In a way it also translates into "what are the challenges in doing X in a touch screen app", and similar questions have been asked here in the past. So here it is: When Apple didn't implement copy-pasting on the iPhone since version 1 I just assumed it was a UI issue- they were waiting until they figured out a good UI for it. But now the idea is out there, and Microsoft still released Windows Phone 7 without copy-pasting, promising it'll be ready in a few months. My question is: why does this takes a few months to implement? Are there some technological challenges that are unique to programming for a touch screen that I'm not familiar with?

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• Could not connect to wireless unitl reboot (nl80211)

  - by user107410

  I'm using Samsung NP900X3C. I have problem with occasionally connecting to WIFI, with Ubuntu 12.10. Sometimes my computer could not connect to WIFI "blab", neither after reboot computer. Only solution is to restart WIFI hotspot. It's public WIFI, used by many users, that don't have that problem. My /var/log/syslog: Nov 12 10:09:39 k15 wpa_supplicant[1308]: wlan0: SME: Trying to authenticate with 64:70:02:89:7c:d7 (SSID='blab' freq=2427 MHz) Nov 12 10:09:39 k15 kernel: [ 8.908610] wlan0: authenticate with 64:70:02:89:7c:d7 Nov 12 10:09:39 k15 NetworkManager[1004]: <info> (wlan0): supplicant interface state: scanning -> authenticating Nov 12 10:09:39 k15 kernel: [ 8.915032] wlan0: send auth to 64:70:02:89:7c:d7 (try 1/3) Nov 12 10:09:39 k15 wpa_supplicant[1308]: wlan0: Trying to associate with 64:70:02:89:7c:d7 (SSID='blab' freq=2427 MHz) Nov 12 10:09:39 k15 kernel: [ 8.916753] wlan0: authenticated Nov 12 10:09:39 k15 kernel: [ 8.916839] wlan0: waiting for beacon from 64:70:02:89:7c:d7 Nov 12 10:09:39 k15 NetworkManager[1004]: <info> (wlan0): supplicant interface state: authenticating -> associating Nov 12 10:09:39 k15 NetworkManager[1004]: <info> (wlan0): supplicant interface state: associating -> disconnected Nov 12 10:09:39 k15 NetworkManager[1004]: <info> (wlan0): supplicant interface state: disconnected -> scanning Nov 12 10:09:42 k15 wpa_supplicant[1308]: wlan0: SME: Trying to authenticate with 64:70:02:89:7c:d7 (SSID='blab' freq=2427 MHz) Nov 12 10:09:42 k15 kernel: [ 12.386212] wlan0: authenticate with 64:70:02:89:7c:d7 Nov 12 10:09:42 k15 wpa_supplicant[1308]: wlan0: Trying to associate with 64:70:02:89:7c:d7 (SSID='blab' freq=2427 MHz) Nov 12 10:09:42 k15 kernel: [ 12.389114] wlan0: send auth to 64:70:02:89:7c:d7 (try 1/3) Nov 12 10:09:42 k15 kernel: [ 12.391021] wlan0: authenticated Nov 12 10:09:42 k15 NetworkManager[1004]: <info> (wlan0): supplicant interface state: scanning -> authenticating Nov 12 10:09:42 k15 kernel: [ 12.391332] wlan0: waiting for beacon from 64:70:02:89:7c:d7 Nov 12 10:09:42 k15 NetworkManager[1004]: <info> (wlan0): supplicant interface state: authenticating -> associating Nov 12 10:09:43 k15 NetworkManager[1004]: <info> (wlan0): supplicant interface state: associating -> disconnected Nov 12 10:09:43 k15 NetworkManager[1004]: <info> (wlan0): supplicant interface state: disconnected -> scanning Nov 12 10:09:46 k15 wpa_supplicant[1308]: wlan0: SME: Trying to authenticate with 64:70:02:89:7c:d7 (SSID='blab' freq=2427 MHz) and after restart WiFi, I could connect: Nov 12 10:11:51 k15 NetworkManager[1004]: <info> (wlan0): supplicant interface state: inactive -> scanning Nov 12 10:11:55 k15 wpa_supplicant[1308]: wlan0: SME: Trying to authenticate with 64:70:02:89:7c:d7 (SSID='blab' freq=2427 MHz) Nov 12 10:11:55 k15 kernel: [ 144.445154] wlan0: authenticate with 64:70:02:89:7c:d7 Nov 12 10:11:55 k15 kernel: [ 144.453994] wlan0: send auth to 64:70:02:89:7c:d7 (try 1/3) Nov 12 10:11:55 k15 wpa_supplicant[1308]: wlan0: Trying to associate with 64:70:02:89:7c:d7 (SSID='blab' freq=2427 MHz) Nov 12 10:11:55 k15 NetworkManager[1004]: <info> (wlan0): supplicant interface state: scanning -> authenticating Nov 12 10:11:55 k15 kernel: [ 144.455860] wlan0: authenticated Nov 12 10:11:55 k15 kernel: [ 144.458681] wlan0: associate with 64:70:02:89:7c:d7 (try 1/3) Nov 12 10:11:55 k15 NetworkManager[1004]: <info> (wlan0): supplicant interface state: authenticating -> associating Nov 12 10:11:55 k15 kernel: [ 144.462799] wlan0: RX AssocResp from 64:70:02:89:7c:d7 (capab=0x431 status=0 aid=9) Nov 12 10:11:55 k15 kernel: [ 144.486368] wlan0: associated Nov 12 10:11:55 k15 wpa_supplicant[1308]: wlan0: Associated with 64:70:02:89:7c:d7 Nov 12 10:11:55 k15 kernel: [ 144.487435] IPv6: ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready Nov 12 10:11:55 k15 NetworkManager[1004]: <info> (wlan0): supplicant interface state: associating -> associated Nov 12 10:11:55 k15 NetworkManager[1004]: <info> (wlan0): supplicant interface state: associated -> 4-way handshake This problem is appearing regulary. My WiFi device control is nl80211. Nov 12 10:09:32 k15 NetworkManager[1004]: <info> (wlan0): using nl80211 for WiFi device control Nov 12 10:09:32 k15 NetworkManager[1004]: <warn> (wlan0): driver supports Access Point (AP) mode Nov 12 10:09:32 k15 NetworkManager[1004]: <info> (wlan0): new 802.11 WiFi device (driver: 'iwlwifi' ifindex: 3) Nov 12 10:09:32 k15 NetworkManager[1004]: <info> (wlan0): exported as /org/freedesktop/NetworkManager/Devices/0 Nov 12 10:09:32 k15 NetworkManager[1004]: <info> (wlan0): now managed Nov 12 10:09:32 k15 NetworkManager[1004]: <info> (wlan0): device state change: unmanaged -> unavailable (reason 'managed') [10 20 2] Nov 12 10:09:32 k15 NetworkManager[1004]: <info> (wlan0): bringing up device.

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• Is there a simple, safe way to trigger a GPU lockup on a susceptible computer?

  - by Abe

  Answers to my previous question, Ubuntu 12.04 froze, requiring powercycle. What should I look / grep for in the logs?, have led me to suspect that my computer is experiencing an intermittent GPU lockup. It has been happening about once a week, usually when I am using Chrome. Today it happened when I was creating a diagram on lucidchart I have a Dell Optiplex 755 with an ATI Radeon HD 2400 XT and dual monitors running in Xinerama mode. I am using 12.04 with the proprietary ATI driver installed. When the computer locks-up, I can still ssh in. And I would like to follow the instructions on reporting this provided at https://wiki.ubuntu.com/X/Troubleshooting/Freeze Is there a (safe) way to cause a GPU lockup so that I can go ahead and file a bug, rather than waiting until it happens again?

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• Windows Phone 7 Developer Tools &ndash; January 2011 Update

  - by TechTwaddle

  Note: I am currently in the process of relocating my blog from http://www.geekswithblogs.net/techtwaddle to my new address at http://www.techtwaddle.net I suggest you point your feed readers to the new address as I slowly transition to my new shared-hosted, ad-free wordpress blog :) If you haven’t heard already, the Jan 2011 update of the windows phone 7 developer tools is out, er, in Feb. You can download the installation files from here, http://www.microsoft.com/downloads/en/details.aspx?FamilyID=49b9d0c5-6597-4313-912a-f0cca9c7d277 The performance increase with the new emulator is clearly noticeable and the first time deploy is real quick! The emulator image should also be a precursor to the windows phone 7 OS update that we’ve been waiting for ever. The emulator image includes copy-paste functionality which is enabled by default on all textboxes, password boxes and edit controls within web browser control, so existing apps get this feature for free. Go ahead and give the new tools a try. If you want to experiment more you might be interested in a unlocked emulator image, follow the link for more information. http://windowsphonehacker.com/latest_windows_phone_7_emulator_unlocked-02-05-11.php

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• Switch from encrypted partition to unencrypted (Error: cryptsetup: evms_activate is not available)

  - by Chris Lercher

  I initially installed Ubuntu 11.04 with an encrypted file system (from the alternate install CD: Guided Partitioning, LVM encrypted). Now I wanted to change this setup to have my root file system on an unencrypted partition. I had the following setup before: /dev/mapper/my-root on / type ext4 (rw,noatime,errors=remount-ro,commit=0,commit=0) /dev/sda1 on /boot type ext2 (rw,noatime) I backed up /, reformatted /dev/sda5 (which had contained the encrypted LVM device) to an ext3 partition, and restored / to that partition. I edited /etc/fstab, removed the line /dev/mapper/my-root / ..., and added the line: /dev/sda5 / ext3 noatime,rw,errors=remount-ro,commit=0 0 1 I edited /etc/crypttab, and commented out the single entry. On reboot, I get the grub screen as usual, but then I get the message cryptsetup:evms_activate is not available, waiting for encrypted source device. I tried reinstalling Grub2 using a LiveCD with the ChRoot method, but that didn't make any difference. Why is Ubuntu still searching for an encrypted device?

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• WIn API Basic Paint program

  - by Tom Burman

  Just trying to learn a bit of Win API. Im trying to make a basic drawing app, a bit like MS Paint. For the time being im trying to get one function to work which is, when you left click and drag the mouse around the screen a line is drawn behind the mouse. Heres what i have so far, but for some reason: 1) the line starts drawing straight away rather then waiting for the left click 2) the line isn't solid its very dotty. case WM_MOUSEMOVE: { if(MK_LBUTTON){ hdc = GetDC(hwnd); hPen = CreatePen(PS_SOLID,5,RGB(0, 0, 255)); SelectObject(hdc, hPen); int x = LOWORD(lParam); int y = HIWORD(lParam); MoveToEx(hdc,x,y,NULL); LineTo(hdc, LOWORD(lParam), HIWORD(lParam)); ReleaseDC(hwnd,hdc); } else break; } } Thanks for any help!

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• Hack Your Kindle for Easy Font Customization

  - by Jason Fitzpatrick

  The font options included with the Kindle are certainly serviceable, but why limit yourself? Today we’ll show you how to easily swap out the font files on your Kindle for a completely customized reading experience. Why customize the font? Why not! It’s your ebook reader and if you want the font to be crisper, thicker, look like it belongs on Star Trek, or pack more words per line, there’s no need to let Amazon’s design decisions stand in your way. Today we’re going to show you how you can install new fonts on your Amazon Kindle with free tools and about 20 minutes of tinkering (most of which will be spent waiting for the Kindle to reboot and rebuild the fonts). Hack Your Kindle for Easy Font Customization HTG Explains: What Is RSS and How Can I Benefit From Using It? HTG Explains: Why You Only Have to Wipe a Disk Once to Erase It

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• Jquery website is not opening in UBUNTU but in XP, Everything is fine

  - by Raman Sethi

  I know it is weird, But I just discovered this, jquery.com is not opening in my ubuntu firefox or other KDE browser and hence many sites that copy codes from code.jquery.com also hanged. Is there any solution to this problem. I have found the problem It is actually with the DNS servers I am using, Google DNS, 8.8.8.8 and 8.8.4.4, whenever I use these DNS in ubuntu my system stop responding to some sites, actually they are connected nicely, but the request end up in waiting.. I dont understand why...??? I checked my DNS with cat /etc/resolv.conf Even after using Google DNS, it is showing DNS servers I received automatically after connecting to the service provider. I am connecting using Network Manager, not using DNS I provided but using the default one. Any Solution??

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• Integrating Azure ServiceBus and SharePoint 2010

  - by Sahil Malik

  SharePoint 2010 Training: more information My new article is finally online. I had been waiting for this for a while. The thing is, AppFabric became .NET 4, and left SharePoint 2010 behind. But fear not, we have REST API. But that brings up interesting challenges of how we can integrate Azure Service Bus with SharePoint 2010 (yes 2010, not vNext – I’m not giving NDA information out you fool), the design patterns you can use, figuring out challenging issues like security, sessions, and just app design patterns instead. Well, I hope you like my next article, SharePoint Applied: Azure ServiceBus and SharePoint 2010 Enjoy! Read full article ....

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• Thread.Interrupt Is Evil

  - by Alois Kraus

  Recently I have found an interesting issue with Thread.Interrupt during application shutdown. Some application was crashing once a week and we had not really a clue what was the issue. Since it happened not very often it was left as is until we have got some memory dumps during the crash. A memory dump usually means WindDbg which I really like to use (I know I am one of the very few fans of it).  After a quick analysis I did find that the main thread already had exited and the thread with the crash was stuck in a Monitor.Wait. Strange Indeed. Running the application a few thousand times under the debugger would potentially not have shown me what the reason was so I decided to what I call constructive debugging. I did create a simple Console application project and try to simulate the exact circumstances when the crash did happen from the information I have via memory dump and source code reading. The thread that was  crashing was actually MS code from an old version of the Microsoft Caching Application Block. From reading the code I could conclude that the main thread did call the Dispose method on the CacheManger class which did call Thread.Interrupt on the cache scavenger thread which was just waiting for work to do. My first version of the repro looked like this   static void Main(string[] args) { Thread t = new Thread(ThreadFunc) { IsBackground = true, Name = "Test Thread" }; t.Start(); Console.WriteLine("Interrupt Thread"); t.Interrupt(); } static void ThreadFunc() { while (true) { object value = Dequeue(); // block until unblocked or awaken via ThreadInterruptedException } } static object WaitObject = new object(); static object Dequeue() { object lret = "got value"; try { lock (WaitObject) { } } catch (ThreadInterruptedException) { Console.WriteLine("Got ThreadInterruptException"); lret = null; } return lret; } I do start a background thread and call Thread.Interrupt on it and then directly let the application terminate. The thread in the meantime does plenty of Monitor.Enter/Leave calls to simulate work on it. This first version did not crash. So I need to dig deeper. From the memory dump I did know that the finalizer thread was doing just some critical finalizers which were closing file handles. Ok lets add some long running finalizers to the sample. class FinalizableObject : CriticalFinalizerObject { ~FinalizableObject() { Console.WriteLine("Hi we are waiting to finalize now and block the finalizer thread for 5s."); Thread.Sleep(5000); } } class Program { static void Main(string[] args) { FinalizableObject fin = new FinalizableObject(); Thread t = new Thread(ThreadFunc) { IsBackground = true, Name = "Test Thread" }; t.Start(); Console.WriteLine("Interrupt Thread"); t.Interrupt(); GC.KeepAlive(fin); // prevent finalizing it too early // After leaving main the other thread is woken up via Thread.Abort // while we are finalizing. This causes a stackoverflow in the CLR ThreadAbortException handling at this time. } With this changed Main method and a blocking critical finalizer I did get my crash just like the real application. The funny thing is that this is actually a CLR bug. When the main method is left the CLR does suspend all threads except the finalizer thread and declares all objects as garbage. After the normal finalizers were called the critical finalizers are executed to e.g. free OS handles (usually). Remember that I did call Thread.Interrupt as one of the last methods in the Main method. The Interrupt method is actually asynchronous and does wake a thread up and throws a ThreadInterruptedException only once unlike Thread.Abort which does rethrow the exception when an exception handling clause is left. It seems that the CLR does not expect that a frozen thread does wake up again while the critical finalizers are executed. While trying to raise a ThreadInterrupedException the CLR goes down with an stack overflow. Ups not so nice. Why has this nobody noticed for years is my next question. As it turned out this error does only happen on the CLR for .NET 4.0 (x86 and x64). It does not show up in earlier or later versions of the CLR. I have reported this issue on connect here but so far it was not confirmed as a CLR bug. But I would be surprised if my console application was to blame for a stack overflow in my test thread in a Monitor.Wait call. What is the moral of this story? Thread.Abort is evil but Thread.Interrupt is too. It is so evil that even the CLR of .NET 4.0 contains a race condition during the CLR shutdown. When the CLR gurus can get it wrong the chances are high that you get it wrong too when you use this constructs. If you do not believe me see what Patrick Smacchia does blog about Thread.Abort and List.Sort. Not only the CLR creators can get it wrong. The BCL writers do sometimes have a hard time with correct exception handling as well. If you do tell me that you use Thread.Abort frequently and never had problems with it I do suspect that you do not have looked deep enough into your application to find such sporadic errors.

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