From dfdad6ab1d4a8f51acca0420de3188b5470f7f16 Mon Sep 17 00:00:00 2001
From: Sebastian Huber <sebastian.huber@embedded-brains.de>
Date: Wed, 8 Oct 2014 10:09:14 +0200
Subject: posix: Fix mutex auto initialization

Use the once lock to prevent race conditions during auto initialization.
---
 cpukit/posix/src/mutexget.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/cpukit/posix/src/mutexget.c b/cpukit/posix/src/mutexget.c
index f683137655..41a5495fa2 100644
--- a/cpukit/posix/src/mutexget.c
+++ b/cpukit/posix/src/mutexget.c
@@ -19,6 +19,7 @@
 #endif
 
 #include <rtems/posix/muteximpl.h>
+#include <rtems/score/apimutex.h>
 
 static bool _POSIX_Mutex_Check_id_and_auto_init(
   pthread_mutex_t   *mutex,
@@ -34,7 +35,15 @@ static bool _POSIX_Mutex_Check_id_and_auto_init(
   if ( *mutex == PTHREAD_MUTEX_INITIALIZER ) {
     int eno;
 
-    eno = pthread_mutex_init( mutex, NULL );
+    _Once_Lock();
+
+    if ( *mutex == PTHREAD_MUTEX_INITIALIZER ) {
+      eno = pthread_mutex_init( mutex, NULL );
+    } else {
+      eno = 0;
+    }
+
+    _Once_Unlock();
 
     if ( eno != 0 ) {
       *location = OBJECTS_ERROR;
-- 
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