[jira] Updated: (THRIFT-488) ThreadManager crashing bugs

["Rush Manbert (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/THRIFT-488?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Rush Manbert updated THRIFT-488:
--------------------------------

    Attachment: ThreadManager.cpp.patch

Patch for ThreadManager.cpp

> ThreadManager crashing bugs
> ---------------------------
>
>                 Key: THRIFT-488
>                 URL: https://issues.apache.org/jira/browse/THRIFT-488
>             Project: Thrift
>          Issue Type: Bug
>          Components: Library (C++)
>    Affects Versions: 0.1
>         Environment: Mac OS X 10.5.6, Xcode
>            Reporter: Rush Manbert
>         Attachments: ThreadManager.cpp.patch
>
>
> The ThreadManager::Impl and the ThreadManager::Worker classes work together to execute client threads. There are race conditions between the two classes that can cause Bus Error exceptions in certain cases. In general, these occur when a ThreadManager instance is destructed, so might not be seen in long running programs. They happen frequently enough, though, that looped repetitions of ThreadManagerTests::blockTest() (part of the concurrency_test program) fail quite often.
> These errors are generally not seen with the current version of ThreadManagerTests::blockTest() due to errors in the test itself that cause failures at a far higher frequency. In order to see them, you need to apply the patches that are attached to THRIFT-487 (https://issues.apache.org/jira/browse/THRIFT-487).
> Test procedure:
> 1) Apply the patch from THRIFT-487 for the Tests.cpp file.
> 2) Run make in lib/cpp in order to rebuild concurrency_test
> 3) Run concurrency_test with the command line argument "thread-manager" and observe that the test hangs in no time.
> 4) Apply the patch from THRIFT-487 for the ThreadManagerTests.h file.
> 5) Run make in lib/cpp
> 6) Run concurrency_test as before. Observe that now it runs for longer (generally) and usually fails with an assert in Monitor.cpp. This failure is because of one of the bugs in ThreadManager.
> 7) Apply the attached patch file for ThreadManager.cpp
> 8) Run make in lib/cpp
> 9) Run concurrency_test as before. It should just run, and run, and run.
> Note that there is a possible path through the original ThreadManager::Worker::run() method where active never becomes true. In practice, exercising this code path is difficuly. The way that I exercised it was to edit line 322 in the patched version of ThreadManager.cpp. I changed the for statement to read:
> for (size_t ix = 0; ix < value + 1; ix++)
> so that the ThreadManager always created more workers than were needed. That extra worker caused quite a bit of trouble until I moved his handling up to the top of the run() method. I don't understand how this situation could occur in real life, but this code appears to handle it correctly.

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