[Bug libstdc++/51636] New: Thread-safeness of new and delete operators

["ingo at pyrillion dot org" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51636

             Bug #: 51636
           Summary: Thread-safeness of new and delete operators
    Classification: Unclassified
           Product: gcc
           Version: 4.6.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libstdc++
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: ingo@pyrillion.org


Dear colleagues,

I had a nasty thread-safeness bug that I finally did not track down completely
(but solved).

My system: Linux ubuntu 3.0.0-14-generic #23-Ubuntu SMP Mon Nov 21 20:28:43 UTC
2011 x86_64 x86_64 x86_64 GNU/Linux
My gcc: gcc (Ubuntu/Linaro 4.6.1-9ubuntu3) 4.6.1
libstdc++: libstdc++.so.6.0.16

Problem: application crashes if too many concurrent POSIX threads get started

Description: application is platform-independent; was developed for Win32/Win64
and Linux 32bit/64bit

If executed with valgrind/hellgrind (Linux) or Microsoft Application Verifier
(Windows 7/64bit), then no errors occur.

If executed on above mentioned host AND more than 100 concurrent threads
performing a lot of new/delete operations, then memory clobbered. Application
was tested using valgrind or GNU mprobe, respectively. GNU mprobe aborts
application with memory clobbered before memory block. All sources compiled
with "-pthread", "-fpic". Error occurs with Debug and Release build. POSIX
threads are performing a mix of new/delete/malloc/free and use thread-specific
data.

My fix: Wrote another shared object implementing malloc/calloc/free/realloc,
new/delete/new[]/delete[] with and without throw(std::bad_alloc). Linking this
shared object to my application fixes the problem.

Guess: the new/new[] operators throwing std::bad_alloc have a MT-safeness
problem.

Sorry for this obfuscating bug report but I am not allowed to disclose more
information. Maybe someone ran into this bug?, too?