3 files changed, 276 insertions, 0 deletions
diff --git a/nuttx/libc/semaphore/Make.defs b/nuttx/libc/semaphore/Make.defs
new file mode 100644
index 000000000..b6551ff96
--- /dev/null
+++ b/nuttx/libc/semaphore/Make.defs
@@ -0,0 +1,43 @@
+############################################################################
+# libc/semaphore/Make.defs
+#
+#   Copyright (C) 2011-2012 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.
+#
+############################################################################
+
+# Add the semaphore C files to the build
+
+CSRCS += sem_init.c sem_getvalue.c
+
+# Add the semaphore directory to the build
+
+DEPPATH += --dep-path semaphore
+VPATH += :semaphore
diff --git a/nuttx/libc/semaphore/sem_getvalue.c b/nuttx/libc/semaphore/sem_getvalue.c
new file mode 100644
index 000000000..ce9d12611
--- /dev/null
+++ b/nuttx/libc/semaphore/sem_getvalue.c
@@ -0,0 +1,108 @@
+/****************************************************************************
+ * libc/semaphore/sem_getvalue.c
+ *
+ *   Copyright (C) 2007-2009, 2011 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 <sys/types.h>
+#include <semaphore.h>
+#include <errno.h>
+
+/****************************************************************************
+ * Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Type Declarations
+ ****************************************************************************/
+
+/****************************************************************************
+ * Global Variables
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Variables
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Function:  sem_getvalue
+ *
+ * Description:
+ *   This function updates the location referenced by 'sval' argument to
+ *   have the value of the semaphore referenced by 'sem' without effecting
+ *   the state of the semaphore.  The updated value represents the actual
+ *   semaphore value that occurred at some unspecified time during the call,
+ *   but may not reflect the actual value of the semaphore when it is
+ *   returned to the calling task.
+ *
+ *   If 'sem' is locked, the value return by sem_getvalue() will either be
+ *   zero or a negative number whose absolute value represents the number
+ *   of tasks waiting for the semaphore.
+ *
+ * Parameters:
+ *   sem - Semaphore descriptor
+ *   sval - Buffer by which the value is returned
+ *
+ * Return Value:
+ *   0 (OK), or -1 (ERROR) if unsuccessful
+ *
+ * Assumptions:
+ *
+ ****************************************************************************/
+
+int sem_getvalue(FAR sem_t *sem, FAR int *sval)
+{
+  if (sem && sval)
+    {
+      *sval = sem->semcount;
+      return OK;
+    }
+  else
+    {
+      set_errno(EINVAL);
+	  return ERROR;
+    }
+}
diff --git a/nuttx/libc/semaphore/sem_init.c b/nuttx/libc/semaphore/sem_init.c
new file mode 100644
index 000000000..7732eb57a
--- /dev/null
+++ b/nuttx/libc/semaphore/sem_init.c
@@ -0,0 +1,125 @@
+/****************************************************************************
+ * libc/sem/sem_init.c
+ *
+ *   Copyright (C) 2007-2009, 2011-2012 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 <sys/types.h>
+#include <limits.h>
+#include <semaphore.h>
+#include <errno.h>
+
+/****************************************************************************
+ * Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Type Declarations
+ ****************************************************************************/
+
+/****************************************************************************
+ * Global Variables
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Variables
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Function: sem_init
+ *
+ * Description:
+ *   This function initializes the UNAMED semaphore sem. Following a
+ *   successful call to sem_init(), the semaophore may be used in subsequent
+ *   calls to sem_wait(), sem_post(), and sem_trywait().  The semaphore
+ *   remains usable until it is destroyed.
+ *
+ *   Only sem itself may be used for performing synchronization. The result
+ *   of referring to copies of sem in calls to sem_wait(), sem_trywait(),
+ *   sem_post(), and sem_destroy() is undefined.
+ *
+ * Parameters:
+ *   sem - Semaphore to be initialized
+ *   pshared - Process sharing (not used)
+ *   value - Semaphore initialization value
+ *
+ * Return Value:
+ *   0 (OK), or -1 (ERROR) if unsuccessful.
+ *
+ * Assumptions:
+ *
+ ****************************************************************************/
+
+int sem_init(FAR sem_t *sem, int pshared, unsigned int value)
+{
+  /* Verify that a semaphore was provided and the count is within the valid
+   * range.
+   */
+
+  if (sem && value <= SEM_VALUE_MAX)
+    {
+      /* Initialize the seamphore count */
+
+      sem->semcount      = (int16_t)value;
+
+      /* Initialize to support priority inheritance */
+
+#ifdef CONFIG_PRIORITY_INHERITANCE
+#  if CONFIG_SEM_PREALLOCHOLDERS > 0
+      sem->hhead         = NULL;
+#  else
+      sem->holder.htcb   = NULL;
+      sem->holder.counts = 0;
+#  endif
+#endif
+      return OK;
+    }
+  else
+    {
+      set_errno(EINVAL);
+      return ERROR;
+    }
+}