1 files changed, 197 insertions, 0 deletions
diff --git a/apps/system/zmodem/zm_watchdog.c b/apps/system/zmodem/zm_watchdog.c
new file mode 100644
index 000000000..48b983acf
--- /dev/null
+++ b/apps/system/zmodem/zm_watchdog.c
@@ -0,0 +1,197 @@
+/****************************************************************************
+ * system/zmodem/zm_watchdog.c
+ *
+ *   Copyright (C) 2013 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 <stdio.h>
+#include <signal.h>
+#include <time.h>
+#include <errno.h>
+
+#include "zm.h"
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: zm_expiry
+ *
+ * Description:
+ *   SIGALRM signal handler.  Simply posts the timeout event.
+ *
+ ****************************************************************************/
+
+static void zm_expiry(int signo, FAR siginfo_t *info, FAR void *context)
+{
+  FAR struct zm_state_s *pzm = (FAR struct zm_state_s *)info->si_value.sival_ptr;
+
+  /* Just set the timeout flag.  If the Zmodem logic was truly waiting, then
+   * the signal should wake it up and it should then process the timeout
+   * condition.
+   *
+   * REVISIT:  This is a read-modify-write operation and has the potential
+   * for atomicity issue.  We might need to use a dedicated boolean value
+   * to indicate to timeout!
+   */
+
+  pzm->flags |= ZM_FLAG_TIMEOUT;
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name:  zm_timerinit
+ *
+ * Description:
+ *   Create the POSIX timer used to manage timeouts and attach the SIGALRM
+ *   signal handler to catch the timeout events.
+ *
+ ****************************************************************************/
+
+int zm_timerinit(FAR struct zm_state_s *pzm)
+{
+  struct sigevent toevent;
+  struct sigaction act;
+  int ret;
+
+  /* Create a POSIX timer to handle timeouts */
+
+  toevent.sigev_notify          = SIGEV_SIGNAL;
+  toevent.sigev_signo           = SIGALRM;
+  toevent.sigev_value.sival_ptr = pzm;
+
+  ret = timer_create(CLOCK_REALTIME, &toevent, &pzm->timer);
+  if (ret < 0)
+    {
+      int errorcode = errno;
+      zmdbg("ERROR: Failed to create a timer: %d\n", errorcode);
+      return -errorcode;
+    }
+
+  /* Attach a signal handler to catch the timeout */
+
+  act.sa_sigaction = zm_expiry;
+  act.sa_flags     = SA_SIGINFO;
+  sigemptyset(&act.sa_mask);
+
+  ret = sigaction(SIGALRM, &act, NULL);
+  if (ret < 0)
+    {
+      int errorcode = errno;
+      zmdbg("ERROR: Failed to attach a signal handler: %d\n", errorcode);
+      return -errorcode;
+    }
+
+  return OK;
+}
+
+/****************************************************************************
+ * Name:  zm_timerstart
+ *
+ * Description:
+ *   Start, restart, or stop the timer.
+ *
+ ****************************************************************************/
+
+int zm_timerstart(FAR struct zm_state_s *pzm, unsigned int sec)
+{
+  struct itimerspec todelay;
+  int ret;
+
+  /* Start, restart, or stop the timer */
+
+  todelay.it_interval.tv_sec    = 0;   /* Nonrepeating */
+  todelay.it_interval.tv_nsec   = 0;
+  todelay.it_value.tv_sec       = sec;
+  todelay.it_value.tv_nsec      = 0;
+
+  ret = timer_settime(pzm->timer, 0, &todelay, NULL);
+  if (ret < 0)
+    {
+      int errorcode = errno;
+      zmdbg("ERROR: Failed to set the timer: %d\n", errorcode);
+      return -errorcode;
+    }
+
+  return OK;
+}
+
+/****************************************************************************
+ * Name:  zm_timerrelease
+ *
+ * Description:
+ *   Destroy the timer and and detach the signal handler.
+ *
+ ****************************************************************************/
+
+int zm_timerrelease(FAR struct zm_state_s *pzm)
+{
+  struct sigaction act;
+  int result;
+  int ret = OK;
+
+  /* Delete the POSIX timer */
+
+  result = timer_delete(pzm->timer);
+  if (result < 0)
+    {
+      int errorcode = errno;
+      zmdbg("ERROR: Failed to delete the timer: %d\n", errorcode);
+      ret = -errorcode;
+    }
+
+  /* Revert to the default signal behavior */
+
+  act.sa_handler = SIG_DFL;
+  act.sa_flags   = 0;
+  sigemptyset(&act.sa_mask);
+
+  result = sigaction(SIGALRM, &act, NULL);
+  if (result < 0)
+    {
+      int errorcode = errno;
+      zmdbg("ERROR: Failed to detach the signal handler: %d\n", errorcode);
+      ret = -errorcode;
+    }
+
+  return ret;
+}