From 8b0472932c1cb8cb2cc46322b21c0c4e21848522 Mon Sep 17 00:00:00 2001
From: Jens Gustedt <Jens.Gustedt@inria.fr>
Date: Sat, 6 Sep 2014 22:07:22 -0400
Subject: add C11 mutex functions

---
 src/thread/mtx_destroy.c   |  5 +++++
 src/thread/mtx_init.c      | 10 ++++++++++
 src/thread/mtx_lock.c      | 12 ++++++++++++
 src/thread/mtx_timedlock.c | 14 ++++++++++++++
 src/thread/mtx_trylock.c   | 17 +++++++++++++++++
 src/thread/mtx_unlock.c    | 11 +++++++++++
 6 files changed, 69 insertions(+)
 create mode 100644 src/thread/mtx_destroy.c
 create mode 100644 src/thread/mtx_init.c
 create mode 100644 src/thread/mtx_lock.c
 create mode 100644 src/thread/mtx_timedlock.c
 create mode 100644 src/thread/mtx_trylock.c
 create mode 100644 src/thread/mtx_unlock.c

diff --git a/src/thread/mtx_destroy.c b/src/thread/mtx_destroy.c
new file mode 100644
index 00000000..40a08999
--- /dev/null
+++ b/src/thread/mtx_destroy.c
@@ -0,0 +1,5 @@
+#include <threads.h>
+
+void mtx_destroy(mtx_t *mtx)
+{
+}
diff --git a/src/thread/mtx_init.c b/src/thread/mtx_init.c
new file mode 100644
index 00000000..4826f76b
--- /dev/null
+++ b/src/thread/mtx_init.c
@@ -0,0 +1,10 @@
+#include "pthread_impl.h"
+#include <threads.h>
+
+int mtx_init(mtx_t *m, int type)
+{
+	*m = (mtx_t){
+		._m_type = ((type&mtx_recursive) ? PTHREAD_MUTEX_RECURSIVE : PTHREAD_MUTEX_NORMAL),
+	};
+	return thrd_success;
+}
diff --git a/src/thread/mtx_lock.c b/src/thread/mtx_lock.c
new file mode 100644
index 00000000..5c2415c1
--- /dev/null
+++ b/src/thread/mtx_lock.c
@@ -0,0 +1,12 @@
+#include "pthread_impl.h"
+#include <threads.h>
+
+int mtx_lock(mtx_t *m)
+{
+	if (m->_m_type == PTHREAD_MUTEX_NORMAL && !a_cas(&m->_m_lock, 0, EBUSY))
+		return thrd_success;
+	/* Calling mtx_timedlock with a null pointer is an extension.
+	 * It is convenient, here to avoid duplication of the logic
+	 * for return values. */
+	return mtx_timedlock(m, 0);
+}
diff --git a/src/thread/mtx_timedlock.c b/src/thread/mtx_timedlock.c
new file mode 100644
index 00000000..bcc152c5
--- /dev/null
+++ b/src/thread/mtx_timedlock.c
@@ -0,0 +1,14 @@
+#include <threads.h>
+#include <errno.h>
+
+int __pthread_mutex_timedlock(mtx_t *restrict, const struct timespec *restrict);
+
+int mtx_timedlock(mtx_t *restrict m, const struct timespec *restrict ts)
+{
+	int ret = __pthread_mutex_timedlock(m, ts);
+	switch (ret) {
+	default:        return thrd_error;
+	case 0:         return thrd_success;
+	case ETIMEDOUT: return thrd_timedout;
+	}
+}
diff --git a/src/thread/mtx_trylock.c b/src/thread/mtx_trylock.c
new file mode 100644
index 00000000..61e7694e
--- /dev/null
+++ b/src/thread/mtx_trylock.c
@@ -0,0 +1,17 @@
+#include "pthread_impl.h"
+#include <threads.h>
+
+int __pthread_mutex_trylock(mtx_t *);
+
+int mtx_trylock(mtx_t *m)
+{
+	if (m->_m_type == PTHREAD_MUTEX_NORMAL)
+		return (a_cas(&m->_m_lock, 0, EBUSY) & EBUSY) ? thrd_busy : thrd_success;
+
+	int ret = __pthread_mutex_trylock(m);
+	switch (ret) {
+	default:    return thrd_error;
+	case 0:     return thrd_success;
+	case EBUSY: return thrd_busy;
+	}
+}
diff --git a/src/thread/mtx_unlock.c b/src/thread/mtx_unlock.c
new file mode 100644
index 00000000..5033ace7
--- /dev/null
+++ b/src/thread/mtx_unlock.c
@@ -0,0 +1,11 @@
+#include <threads.h>
+
+int __pthread_mutex_unlock(mtx_t *);
+
+int mtx_unlock(mtx_t *mtx)
+{
+	/* The only cases where pthread_mutex_unlock can return an
+	 * error are undefined behavior for C11 mtx_unlock, so we can
+	 * assume it does not return an error and simply tail call. */
+	return __pthread_mutex_unlock(mtx);
+}
-- 
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