[Boost-bugs] [Boost C++ Libraries] #4639: boost thread library leaks pthread_key

Subject: [Boost-bugs] [Boost C++ Libraries] #4639: boost thread library leaks pthread_key
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2010-09-08 21:04:11

#4639: boost thread library leaks pthread_key
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 Reporter:  gleonid@…                              |       Owner:  anthonyw
     Type:  Bugs                                   |      Status:  new     
Milestone:  To Be Determined                       |   Component:  thread  
  Version:  Boost 1.44.0                           |    Severity:  Problem 
 Keywords:  pthread_key_create pthread_key_delete  |  
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 implementation on Linux of boost::thread_specific_ptr calls
 pthread_key_create, but never calls pthread_key_delete.

 On RHEL 4.6 system pthread_key_create succeeds 1024 times in a row without
 calling pthread_key_delete. After that point pthread_key_create fails.

 Basically there are 2 issues:
 1. resource leak - boost thread should release acquired resource
 2. When/if pthread_key_create fails - current (1.44.0) implementation
 completely ignores return code in release version.

 I am attaching test case to illustrate/reproduce problem.

 Debug version yields:
 ''attempt 512
 boost_thread_test_deb.exe: libs/thread/src/pthread/once.cpp:32: void
 boost::detail::<unnamed>::create_epoch_tss_key(): Assertion
 `!pthread_key_create(&epoch_tss_key,delete_epoch_tss_data)' failed.
 Aborted
 ''
 While release version results in following:
 ''attempt 512
 Segmentation fault''

 Here is a brief explanation of why I need to dlopen/dlclose same shared
 object repeatedly:

 I am working on apache's module and I am using boost::thread_specific_ptr
 in my module. I am linking with boost thread library statically.

 In our organization apache is being gracefully restarted (apachectl
 graceful) every hour. During every restart my module is being unloaded
 (along with boost thread) and loaded back again. This usage scenario gives
 me 512 restarts/reloads, which translates to 21 days before it segfaults.

 After closer examination I found out that even if do not
 boost::thread_specific_ptr use directly - I am still subject to this
 problem as boost::thread also uses it.
 All of the above prevents me from using boost thread library in my
 project.

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/4639>
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