1
0
mirror of https://github.com/samba-team/samba.git synced 2025-01-14 19:24:43 +03:00
Stefan Metzmacher 5fa5764f30 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>
2018-07-24 17:38:26 +02:00
..
2016-12-01 18:08:54 +01:00
2014-09-19 18:11:11 +02:00
2017-06-13 09:11:56 +02:00

This directory contains wrappers around logical groups of system
include files. The idea is to avoid #ifdef blocks in the main code,
and instead put all the necessary conditional includes in subsystem
specific header files in this directory.