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ASF GitHub Bot commented on THRIFT-3932: ---------------------------------------- Github user jeking3 commented on a diff in the pull request: https://github.com/apache/thrift/pull/1103#discussion_r81470853 --- Diff: lib/cpp/src/thrift/concurrency/PosixThreadFactory.h --- @@ -39,7 +39,14 @@ class PosixThreadFactory : public ThreadFactory { /** * POSIX Thread scheduler policies */ - enum POLICY { OTHER, FIFO, ROUND_ROBIN }; + class Policy { + public: + enum value { + OTHER = 0, + FIFO = 1, + ROUND_ROBIN = 2 + }; --- End diff -- I'll revert the enum changes. > C++ ThreadManager has a rare termination race > --------------------------------------------- > > Key: THRIFT-3932 > URL: https://issues.apache.org/jira/browse/THRIFT-3932 > Project: Thrift > Issue Type: Bug > Components: C++ - Library > Reporter: Buğra Gedik > Assignee: James E. King, III > Attachments: thrift-patch > > Time Spent: 8h > Remaining Estimate: 0h > > {{ThreadManger::join}} calls {{stopImpl(true)}}, which in turn calls > {{removeWorker(workerCount_);}}. The latter waits until {{while (workerCount_ > != workerMaxCount_)}}. Within the {{run}} method of the workers, the last > thread that detects {{workerCount_ == workerMaxCount_}} notifies > {{removeWorker}}. The {{run}} method has the following additional code that > is executed at the very end: > {code} > { > Synchronized s(manager_->workerMonitor_); > manager_->deadWorkers_.insert(this->thread()); > if (notifyManager) { > manager_->workerMonitor_.notify(); > } > } > {code} > This is an independent synchronized block. Now assume 2 threads. One of them > has {{notifyManager=true}} as it detected the {{workerCount_ == > workerMaxCount_}} condition earlier. It is possible that this thread gets to > execute the above code block first, {{ThreadManager}}'s {{removeWorker}} > method unblocks, and eventually {{ThreadManager}}'s {{join}} returns and the > object is destructed. When the other thread reaches the synchronized block > above, it will crash, as the manager is not around anymore. > Besides, {{ThreadManager}} never joins its threads. > Attached is a patch. -- This message was sent by Atlassian JIRA (v6.3.4#6332)