From e3940eb2080711edac189cca3f642ee89dc215f2 Mon Sep 17 00:00:00 2001
From: patacongo <patacongo@42af7a65-404d-4744-a932-0658087f49c3>
Date: Sat, 17 Feb 2007 23:21:28 +0000
Subject: NuttX RTOS

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@3 42af7a65-404d-4744-a932-0658087f49c3
---
 nuttx/sched/pthread_mutexlock.c | 138 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 138 insertions(+)
 create mode 100644 nuttx/sched/pthread_mutexlock.c

(limited to 'nuttx/sched/pthread_mutexlock.c')

diff --git a/nuttx/sched/pthread_mutexlock.c b/nuttx/sched/pthread_mutexlock.c
new file mode 100644
index 000000000..43e7c8356
--- /dev/null
+++ b/nuttx/sched/pthread_mutexlock.c
@@ -0,0 +1,138 @@
+/************************************************************
+ * pthread_mutexlock.c
+ *
+ *   Copyright (C) 2007 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *
+ * 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 Gregory Nutt 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 <sys/types.h>
+#include <unistd.h>
+#include <pthread.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
+ ************************************************************/
+
+/************************************************************
+ * Function:  pthread_mutex_lock
+ *
+ * Description:
+ *   Lock a mutex.
+ *
+ * Parameters:
+ *   None
+ *
+ * Return Value:
+ *   None
+ *
+ * Assumptions:
+ *
+ ************************************************************/
+
+int pthread_mutex_lock(pthread_mutex_t *mutex)
+{
+  int mypid = (int)getpid();
+  int ret = OK;
+
+  dbg("%s: mutex=0x%p\n", __FUNCTION__, 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();
+
+      /* Does this task already hold the semaphore? */
+
+      if (mutex->pid == mypid)
+        {
+          dbg("%s: Returning EDEADLK\n", __FUNCTION__);
+          ret = EDEADLK;
+        }
+      else
+        {
+          /* Take the semaphore */
+
+          ret = pthread_takesemaphore((sem_t*)&mutex->sem);
+
+          /* If we succussfully obtained the semaphore, then indicate
+           * that we own it.
+           */
+
+          if (!ret)
+            {
+              mutex->pid = mypid;
+            }
+        }
+      sched_unlock();
+    }
+
+  dbg("%s: Returning %d\n", __FUNCTION__, ret);
+  return ret;
+}
+
+
+
+
-- 
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