Multi-thread concurrency issue During our concurrency testing, we observed NullPointer exceptions being thrown when two people hit the same page at the same time for the first time. Upon further investigation, it turns out that we need to synchronize the init method on ASTDirective, ASTSetDirective, and render method on ASTSetDirective, and VelocimacroProxy.
Basically, the problem is introduced as the following; when two threads attempts to parse and render the same template at the same time. Thread1 finishes parsing first and proceeds to the render method call, while thread 2 is still busy parsing and will overwrite the existing parse tree that is being used by thread 1 for rendering purpose. Thus under certainly condition a NullPointer exception will be thrown. I have run through all existing test cases successfully and the memory saving has been verified by YourKit profiler. http://www.nabble.com/file/7596/node-patch.txt patch.txt http://www.nabble.com/file/7593/VelocimacroProxy.java VelocimacroProxy.java http://www.nabble.com/file/7594/ASTSetDirective.java ASTSetDirective.java http://www.nabble.com/file/7595/ASTDirective.java ASTDirective.java Thanks. -- Lei -- View this message in context: http://www.nabble.com/Fixes-for-Multi-threaded-concurrency-issue-only--resubmitted-tf3497213.html#a9768199 Sent from the Velocity - Dev mailing list archive at Nabble.com. --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
