From d90f684f162d4b91a58b61bb2a60ec1257c1dd70 Mon Sep 17 00:00:00 2001
From: Chris Robinson <chris.kcat@gmail.com>
Date: Thu, 1 May 2014 14:15:31 -0700
Subject: [PATCH] Use a backup in case pthread_mutex_timedlock isn't available

---
 Alc/threads.c  | 24 +++++++++++++++++++++++-
 CMakeLists.txt |  2 ++
 config.h.in    |  3 +++
 3 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/Alc/threads.c b/Alc/threads.c
index 81db4297..0325c104 100644
--- a/Alc/threads.c
+++ b/Alc/threads.c
@@ -447,7 +447,10 @@ void almtx_destroy(almtx_t *mtx)
 
 int almtx_timedlock(almtx_t *mtx, const struct timespec *ts)
 {
-    int ret = pthread_mutex_timedlock(mtx, ts);
+    int ret;
+
+#ifdef HAVE_PTHREAD_MUTEX_TIMEDLOCK
+    ret = pthread_mutex_timedlock(mtx, ts);
     switch(ret)
     {
         case 0: return althrd_success;
@@ -455,6 +458,25 @@ int almtx_timedlock(almtx_t *mtx, const struct timespec *ts)
         case EBUSY: return althrd_busy;
     }
     return althrd_error;
+#else
+    if(!mtx || !ts)
+        return althrd_error;
+
+    while((ret=almtx_trylock(mtx)) == althrd_busy)
+    {
+        struct timespec now;
+
+        if(ts->tv_sec < 0 || ts->tv_nsec < 0 || ts->tv_nsec >= 1000000000 ||
+           altimespec_get(&now, AL_TIME_UTC) != AL_TIME_UTC)
+            return althrd_error;
+        if(now.tv_sec > ts->tv_sec || (now.tv_sec == ts->tv_sec && now.tv_nsec >= ts->tv_nsec))
+            return althrd_timedout;
+
+        althrd_yield();
+    }
+
+    return ret;
+#endif
 }
 
 
diff --git a/CMakeLists.txt b/CMakeLists.txt
index e42288ad..3f1674a5 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -460,6 +460,8 @@ IF(NOT HAVE_WINDOWS_H)
         CHECK_SYMBOL_EXISTS(pthread_mutexattr_setkind_np "pthread.h;pthread_np.h" HAVE_PTHREAD_MUTEXATTR_SETKIND_NP)
     ENDIF()
 
+    CHECK_SYMBOL_EXISTS(pthread_mutex_timedlock pthread.h HAVE_PTHREAD_MUTEX_TIMEDLOCK)
+
     CHECK_LIBRARY_EXISTS(rt clock_gettime "" HAVE_LIBRT)
     IF(HAVE_LIBRT)
         SET(EXTRA_LIBS rt ${EXTRA_LIBS})
diff --git a/config.h.in b/config.h.in
index 33eb5b62..e8b944f6 100644
--- a/config.h.in
+++ b/config.h.in
@@ -184,3 +184,6 @@
 
 /* Define if we have pthread_mutexattr_setkind_np() */
 #cmakedefine HAVE_PTHREAD_MUTEXATTR_SETKIND_NP
+
+/* Define if we have pthread_mutex_timedlock() */
+#cmakedefine HAVE_PTHREAD_MUTEX_TIMEDLOCK
-- 
2.11.4.GIT