commit 9d0ad2d40ee86ad47913b06b7585d67bd216ce4f
author Jonathan Wakely <jwakely@redhat.com> Thu Mar 05 16:53:20 2020 +0000
committer Jonathan Wakely <jwakely@redhat.com> Thu Mar 05 17:43:16 2020 +0000
tree 2acbdacaeac2e393b5f1783b3be8c89219b72124
parent 494166791ea6b669f17cf3fbb037000396018420

PR libstdc++/91910 fix data race in Debug Mode destructors

Fix data race when _Safe_iterator_base::_M_detach() runs concurrently with
the _Safe_container_base destructor.

Backport from mainline
2019-09-27  Jonathan Wakely  <jwakely@redhat.com>

	PR libstdc++/91910
	* src/c++11/debug.cc (_Safe_iterator_base::_M_detach()): Load pointer
	atomically and lock the mutex before accessing the sequence.
	(_Safe_local_iterator_base::_M_detach()): Likewise.
	(_Safe_iterator_base::_M_reset()): Clear _M_sequence atomically.