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From: "redi at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
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Subject: [Bug libstdc++/60966] std::call_once sometime hangs
Date: Wed, 14 May 2014 10:43:00 -0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=60966

--- Comment #13 from Jonathan Wakely <redi at gcc dot gnu.org> ---
(In reply to Hideaki Kimura from comment #11)
> Hi, I'm also (seemingly) hitting this issue.
> When I run my program with valgrind, I get what Thomas reported.
> 
> ==22319== Invalid read of size 4
> ==22319==    at 0x370940D201: pthread_once (pthread_once.S:111)
> ==22319==    by 0x4C80524: ....<my functions> (gthr-default.h:699)
> ...
> ==22319==  Address 0x52c52a4 is 132 bytes inside a block of size 136 free'd
> ==22319==    at 0x4A07991: operator delete(void*) (in
> /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
> ==22319==    by 0x4C82456: ...<my function> (shared_ptr_base.h:161)
> ==22319==    by 0x370C4B52AF: execute_native_thread_routine (thread.cc:84)
> ==22319==    by 0x3709407F32: start_thread (pthread_create.c:309)
> ==22319==    by 0x37090F4DEC: clone (clone.S:111)
> ==22319== 

This means you are waiting on an object that has gone out of scope. WIthout
more information it's not possible to tell if this is a bug in your program or
the standard libary.

I'll try to reproduce it with Thomas's code...