Implement pause()

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@5376 42af7a65-404d-4744-a932-0658087f49c3

2 files changed, 111 insertions, 1 deletions

diff --git a/nuttx/sched/Makefile b/nuttx/sched/Makefile
index 9b15108f4..82f74fc3c 100644
--- a/nuttx/sched/Makefile
+++ b/nuttx/sched/Makefile
@@ -94,7 +94,7 @@ SIGNAL_SRCS	= sig_initialize.c \
 		  sig_findaction.c sig_allocatependingsigaction.c \
 		  sig_releasependingsigaction.c sig_unmaskpendingsignal.c \
 		  sig_removependingsignal.c sig_releasependingsignal.c sig_lowest.c \
-		  sig_mqnotempty.c sig_cleanup.c sig_received.c sig_deliver.c
+		  sig_mqnotempty.c sig_cleanup.c sig_received.c sig_deliver.c pause.c
 
 MQUEUE_SRCS	= mq_open.c mq_close.c mq_unlink.c mq_send.c mq_timedsend.c\
 		  mq_sndinternal.c mq_receive.c mq_timedreceive.c mq_rcvinternal.c \
diff --git a/nuttx/sched/pause.c b/nuttx/sched/pause.c
new file mode 100644
index 000000000..fb5542d84
--- /dev/null
+++ b/nuttx/sched/pause.c
@@ -0,0 +1,110 @@
+/****************************************************************************
+ * sched/pause.c
+ *
+ *   Copyright (C) 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 <unistd.h>
+#include <signal.h>
+
+/****************************************************************************
+ * Preprocessor Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Type Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Global Variables
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Variables
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: pause
+ *
+ * Description:
+ *   The pause() function will suspend the calling thread until delivery of a
+ *   non-blocked signal.
+ *
+ * Input Parameters:
+ *   None
+ *
+ * Returned Value:
+ *   Since pause() suspends thread execution indefinitely unless interrupted 
+ *   a signal, there is no successful completion return value. A value of -1
+ *   will always be returned and errno set to indicate the error (EINTR).
+ *
+ * POSIX compatibility:
+ *   In the POSIX description of this function is the pause() function will
+ *   suspend the calling thread until delivery of a signal whose action is
+ *   either to execute a signal-catching function or to terminate the
+ *   process.  This implementation only waits for any non-blocked signal
+ *   to be recieved.
+ *
+ ****************************************************************************/
+
+int pause(void)
+{
+  sigset_t set;
+  struct siginfo value;
+ 
+  /* Set up for the sleep.  Using the empty set means that we are not
+   * waiting for any particualar signal.  However, any unmasked signal
+   * can still awaken sigtimedwait().
+   */
+
+  (void)sigemptyset(&set);
+
+  /* sigtwaitinfo() cannot succeed.  It should always return error EINTR
+   * meaning that some unblocked signal was caught.
+   */
+
+  return sigwaitinfo(&set, &value);
+}