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Liu Lin commented on THRIFT-4004: ---------------------------------- I have checked the lastest codes from github. The analysis still holds. > ThreadManager deadlock when adding new task > ------------------------------------------- > > Key: THRIFT-4004 > URL: https://issues.apache.org/jira/browse/THRIFT-4004 > Project: Thrift > Issue Type: Bug > Components: C++ - Library > Affects Versions: 0.9.3 > Reporter: Liu Lin > Assignee: James E. King, III > > Set pendingTaskCountMax = 1. > Add only 1 worker into ThreadManager. > When adding task, set timeout > 0. > If there is no task, worker thread will sleep, because > manager_->monitor_.wait(Line 259) is called in function > ThreadManager::Worker::run. > Then suppose we have 2 tasks. We add the first task by calling > ThreadManager::Impl::add, which will nofity monitor_. But before > manager_->monitor_.wait() returns, we call ThreadManager::Impl::add again. If > ThreadManager::Impl::add gets lock mutex_ successfully, > ThreadManager::Worker::run will fall asleep again because it can not lock > mutex_. > Now we have tasks_.size() == pendingTaskCountMax_, so > ThreadManager::Impl::add will wait on maxMonitor_(Line 462). Becasue the > worker cannot fetch a task(because it can not lock mutex_, it will not notify > maxMonitor_), so ThreadManager::Impl::add will wait forever. > Now both the two threads wait for each other, result in deadlock. -- This message was sent by Atlassian JIRA (v6.3.4#6332)