https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94936
--- Comment #3 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-10 branch has been updated by Jonathan Wakely <r...@gcc.gnu.org>: https://gcc.gnu.org/g:6b19640035d2df46758c7d31e5aab1186518e514 commit r10-8449-g6b19640035d2df46758c7d31e5aab1186518e514 Author: Jonathan Wakely <jwak...@redhat.com> Date: Mon May 4 13:34:23 2020 +0100 libstdc++: Make pmr::synchronized_pool_resource work without libpthread (PR 94936) I implicitly assumed that programs using pmr::synchronized_pool_resource would also be using multiple threads, and so the weak symbols in gthr-posix.h would be resolved by linking to libpthread. If that isn't true then it crashes when trying to use pthread_key_create. This commit makes the pool resource check __gthread_active_p() before using thread-specific data, and just use a single set of memory pools when there's only a single thread. PR libstdc++/94936 * src/c++17/memory_resource.cc (synchronized_pool_resource::_TPools): Add comment about single-threaded behaviour. (synchronized_pool_resource::_TPools::move_nonempty_chunks()): Hoist class member access out of loop. (synchronized_pool_resource::synchronized_pool_resource()) (synchronized_pool_resource::~synchronized_pool_resource()) (synchronized_pool_resource::release()): Check __gthread_active_p before creating and/or deleting the thread-specific data key. (synchronized_pool_resource::_M_thread_specific_pools()): Adjust assertions. (synchronized_pool_resource::do_allocate(size_t, size_t)): Add fast path for single-threaded case. (synchronized_pool_resource::do_deallocate(void*, size_t, size_t)): Likewise. Return if unable to find a pool that owns the allocation. * testsuite/20_util/synchronized_pool_resource/allocate_single.cc: New test. * testsuite/20_util/synchronized_pool_resource/cons_single.cc: New test. * testsuite/20_util/synchronized_pool_resource/release_single.cc: New test. (cherry picked from commit ec40967f1323069da3a5a45286f71fa4f80926df)
