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author | Stefan Metzmacher <metze@samba.org> | 2018-06-21 14:17:35 +0200 |
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committer | Ralph Boehme <slow@samba.org> | 2018-07-24 17:38:26 +0200 |
commit | 5fa5764f30c47b46f12ceb7637985e8def0190ca (patch) | |
tree | dd339ab817291e511076a07bf86d8e9f4ece65e0 /wscript | |
parent | 6f8c1b6736875d63c11f8630ecf1c8d3dcd70fc5 (diff) | |
download | samba-5fa5764f30c47b46f12ceb7637985e8def0190ca.tar.gz |
replace: add checks for atomic_thread_fence(memory_order_seq_cst) and add possible fallbacks
This implements a full memory barrier.
On ubuntu amd64 with results in an 'mfence' instruction.
This is required to syncronization between threads, where
there's typically only one write of a memory that should be
synced between all threads with the barrier.
Much more details can be found here:
https://gcc.gnu.org/onlinedocs/gcc-7.3.0/gcc/_005f_005fatomic-Builtins.html#g_t_005f_005fatomic-Builtins
https://gcc.gnu.org/onlinedocs/gcc-7.3.0/gcc/_005f_005fsync-Builtins.html#g_t_005f_005fsync-Builtins
The main one we use seems to be in C11 via stdatomic.h,
the oldest fallback is __sync_synchronize(), which is available
since 2005 in gcc.
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Ralph Boehme <slow@samba.org>
Diffstat (limited to 'wscript')
0 files changed, 0 insertions, 0 deletions