1 files changed, 147 insertions, 0 deletions
diff --git a/nuttx/sched/pthread_mutextrylock.c b/nuttx/sched/pthread_mutextrylock.c
new file mode 100644
index 000000000..d88012b51
--- /dev/null
+++ b/nuttx/sched/pthread_mutextrylock.c
@@ -0,0 +1,147 @@
+/****************************************************************************
+ * sched/pthread_mutextrylock.c
+ *
+ *   Copyright (C) 2007-2009 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <unistd.h>
+#include <pthread.h>
+#include <semaphore.h>
+#include <sched.h>
+#include <errno.h>
+#include <debug.h>
+
+#include "pthread_internal.h"
+
+/****************************************************************************
+ * Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Type Declarations
+ ****************************************************************************/
+
+/****************************************************************************
+ * Global Variables
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Variables
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: pthread_mutex_trylock
+ *
+ * Description:
+ *   The function pthread_mutex_trylock() is identical to pthread_mutex_lock()
+ *   except that if the mutex object referenced by mutex is currently locked
+ *   (by any thread, including the current thread), the call returns immediately
+ *   with the errno EBUSY.
+ *
+ *   If a signal is delivered to a thread waiting for a mutex, upon return from
+ *   the signal handler the thread resumes waiting for the mutex as if it was
+ *   not interrupted.
+ *
+ * Parameters:
+ *   mutex - A reference to the mutex to be locked.
+ *
+ * Return Value:
+ *   0 on success or an errno value on failure.  Note that the errno EINTR
+ *   is never returned by pthread_mutex_lock().
+ *
+ * Assumptions:
+ *
+ ****************************************************************************/
+
+int pthread_mutex_trylock(FAR pthread_mutex_t *mutex)
+{
+  int ret = OK;
+
+  sdbg("mutex=0x%p\n", mutex);
+
+  if (!mutex)
+    {
+      ret = EINVAL;
+    }
+  else
+    {
+      /* Make sure the semaphore is stable while we make the following
+       * checks.  This all needs to be one atomic action.
+       */
+
+      sched_lock();
+
+      /* Try to get the semaphore. */
+
+      if (sem_trywait((sem_t*)&mutex->sem) == OK)
+        {
+          /* If we succussfully obtained the semaphore, then indicate
+           * that we own it.
+           */
+
+          mutex->pid = (int)getpid();
+        }
+
+      /* Was it not available? */
+
+      else if (get_errno() == EAGAIN)
+        {
+          ret = EBUSY;
+        }
+      else
+        {
+          ret = EINVAL;
+        }
+
+      sched_unlock();
+    }
+
+  sdbg("Returning %d\n", ret);
+  return ret;
+}
+
+
+