https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94160
--- Comment #2 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Jonathan Wakely <r...@gcc.gnu.org>: https://gcc.gnu.org/g:30b41cfbb2dade63e52465234a725d1d02fe70aa commit r11-3102-g30b41cfbb2dade63e52465234a725d1d02fe70aa Author: Jonathan Wakely <jwak...@redhat.com> Date: Thu Sep 10 15:39:15 2020 +0100 libstdc++: handle small max_blocks_per_chunk in pool resources [PR 94160] When a pool resource is constructed with max_blocks_per_chunk=1 it ends up creating a pool with blocks_per_chunk=0 which means it never allocates anything. Instead it returns null pointers, which should be impossible. To avoid this problem, round the max_blocks_per_chunk value to a multiple of four, so it's never smaller than four. libstdc++-v3/ChangeLog: PR libstdc++/94160 * src/c++17/memory_resource.cc (munge_options): Round max_blocks_per_chunk to a multiple of four. (__pool_resource::_M_alloc_pools()): Simplify slightly. * testsuite/20_util/unsynchronized_pool_resource/allocate.cc: Check that valid pointers are returned when small values are used for max_blocks_per_chunk.
