samba.git/lib/replace/system/threads.h, branch master

replace: add checks for atomic_thread_fence(memory_order_seq_cst) and add possible fallbacks

2018-07-24T15:38:26+00:00

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 
Reviewed-by: Ralph Boehme

lib/replace: fix PTHREAD_MUTEX_ROBUST fallback to PTHREAD_MUTEX_ROBUST_NP on solaris 11

2015-06-12T15:08:20+00:00

Without this we got the following defines in config.h:

   #define HAVE_DECL_PTHREAD_MUTEXATTR_SETROBUST_NP 1
   #define HAVE_DECL_PTHREAD_MUTEX_CONSISTENT_NP 1
   #define HAVE_PTHREAD_MUTEXATTR_SETROBUST 1
   #define HAVE_PTHREAD_MUTEX_CONSISTENT 1
   #define HAVE_ROBUST_MUTEXES 1
   #define USE_TDB_MUTEX_LOCKING 1

And the build failed with PTHREAD_MUTEX_ROBUST being unknown.

Note that PTHREAD_MUTEX_ROBUST and PTHREAD_MUTEX_ROBUST_NP are enum values
while they're defines on solaris 11
BUG: https://bugzilla.samba.org/show_bug.cgi?id=11319

Signed-off-by: Stefan Metzmacher 
Reviewed-by: Michael Adam

libreplace: Define PTHREAD_MUTEX_ROBUST along with pthread_mutexattr_setrobust

2014-05-22T19:05:15+00:00

Signed-off-by: Volker Lendecke 
Reviewed-by: Stefan Metzmacher 
Reviewed-by: Jeremy Allison

libreplace: Add support for pthread_mutex_consistent

2014-05-22T19:05:15+00:00

Signed-off-by: Volker Lendecke 
Reviewed-by: Stefan Metzmacher 
Reviewed-by: Jeremy Allison

libreplace: Add support for pthread_mutexattr_setrobust

2014-05-22T19:05:15+00:00

Signed-off-by: Volker Lendecke 
Reviewed-by: Stefan Metzmacher 
Reviewed-by: Jeremy Allison