I know this is an old question but I just wrote a tool to help make long thread dumps more readable. Java Thread Dump Analysis Tool This tool groups threads together which have the same stack trace and allows you to only show threads which are in particular states (e.g. RUNNABLE or BLOCKED). This makes … Read more
You can do this programmatically using the ThreadMXBean that ships with the JDK: ThreadMXBean bean = ManagementFactory.getThreadMXBean(); long[] threadIds = bean.findDeadlockedThreads(); // Returns null if no threads are deadlocked. if (threadIds != null) { ThreadInfo[] infos = bean.getThreadInfo(threadIds); for (ThreadInfo info : infos) { StackTraceElement[] stack = info.getStackTrace(); // Log or store stack trace information. … Read more
Don’t forget to supress your select statements from your TransactionScope. In SQL Server 2005 and above, even when you use with(nolock), locks are still created on those tables the select touches. Check this out, it shows you how to setup and use TransactionScope. using(TransactionScope ts = new TransactionScope { // db calls here are in … Read more
Since JDK 1.5 there are very useful methods in the java.lang.management package to find and inspect deadlocks that occurs. See the findMonitorDeadlockedThreads() and findDeadlockedThreads() method of the ThreadMXBean class. A possible way to use this is to have a separate watchdog thread (or periodic task) that does this. Sample code: ThreadMXBean tmx = ManagementFactory.getThreadMXBean(); long[] … Read more
Think of a race condition using the traditional example. Say you and a friend have an ATM cards for the same bank account. Now suppose the account has $100 in it. Consider what happens when you attempt to withdraw $10 and your friend attempts to withdraw $50 at exactly the same time. Think about what … Read more
These are the workarounds I’ve found to this deadlock problem: Workaround #1 By default StackExchange.Redis will ensure that commands are completed in the same order that result messages are received. This could cause a deadlock as described in this question. Disable that behavior by setting PreserveAsyncOrder to false. ConnectionMultiplexer connection = …; connection.PreserveAsyncOrder = false; … Read more
In the SQL Server Management Studio, to find out details of the active transaction, execute following command DBCC opentran() You will get the detail of the active transaction, then from the SPID of the active transaction, get the detail about the SPID using following commands exec sp_who2 <SPID> exec sp_lock <SPID> For example, if SPID … Read more
Had a similar issue, VS would hang for 45 or so seconds then build for 4 seconds and complete. The 45 seconds of hang would not produce any output to GUI and VS would hang. Using ProcMon I could see 3 million+ file operations on the /packages/ folder via devenv.exe when I would build this … Read more
According to MSDN: http://msdn.microsoft.com/en-us/library/ms191242.aspx When either the READ COMMITTED SNAPSHOT or ALLOW SNAPSHOT ISOLATION database options are ON, logical copies (versions) are maintained for all data modifications performed in the database. Every time a row is modified by a specific transaction, the instance of the Database Engine stores a version of the previously committed image … Read more
UPDATE: This question was the subject of my blog in January 2013. Thanks for the great question! How can we write a program that will always go into deadlock no matter how the threads are scheduled? Here’s an example in C#. Note that the program appears to contain no locks and no shared data. It … Read more