5.5 merge

1 files changed, 32 insertions, 0 deletions

diff --git a/storage/innobase/include/os0sync.ic b/storage/innobase/include/os0sync.ic
index 9a7e520ece6..4ebf84dba98 100644
--- a/storage/innobase/include/os0sync.ic
+++ b/storage/innobase/include/os0sync.ic
@@ -232,3 +232,35 @@ win_cmp_and_xchg_dword(
 
 #endif /* HAVE_WINDOWS_ATOMICS */
 
+
+/**********************************************************//**
+Acquires ownership of a fast mutex. Implies a full memory barrier even on
+platforms such as PowerPC where this is not normally required.
+@return	0 if success, != 0 if was reserved by another thread */
+UNIV_INLINE
+ulint
+os_fast_mutex_trylock_full_barrier(
+/*==================*/
+	os_fast_mutex_t*	fast_mutex)	/*!< in: mutex to acquire */
+{
+#ifdef __WIN__
+	if (TryEnterCriticalSection(&fast_mutex->mutex)) {
+
+		return(0);
+	} else {
+
+		return(1);
+	}
+#else
+	/* NOTE that the MySQL my_pthread.h redefines pthread_mutex_trylock
+	so that it returns 0 on success. In the operating system
+	libraries, HP-UX-10.20 follows the old Posix 1003.4a Draft 4 and
+	returns 1 on success (but MySQL remaps that to 0), while Linux,
+	FreeBSD, Solaris, AIX, Tru64 Unix, HP-UX-11.0 return 0 on success. */
+
+#ifdef __powerpc__
+	os_mb;
+#endif
+	return((ulint) pthread_mutex_trylock(&fast_mutex->mutex));
+#endif
+}