This is an automated email from the ASF dual-hosted git repository.
acassis pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/incubator-nuttx-apps.git
commit c3494c310abf63b6913266c3cde87bb57fdc1115
Author: Sara Souza <sara.so...@espressif.com>
AuthorDate: Thu Nov 19 15:41:37 2020 -0300
examples: Added watcher and watched examples.
---
examples/watched/Kconfig | 35 +++++
examples/watched/Make.defs | 24 +++
examples/watched/Makefile | 35 +++++
examples/watched/watched.c | 176 ++++++++++++++++++++++
examples/watched/watched.h | 79 ++++++++++
examples/watched/watched_main.c | 180 +++++++++++++++++++++++
examples/watcher/Kconfig | 49 +++++++
examples/watcher/Make.defs | 23 +++
examples/watcher/Makefile | 35 +++++
examples/watcher/ramdisk.c | 138 ++++++++++++++++++
examples/watcher/ramdisk.h | 56 +++++++
examples/watcher/task_mn.c | 313 ++++++++++++++++++++++++++++++++++++++++
examples/watcher/task_mn.h | 79 ++++++++++
examples/watcher/watcher_main.c | 234 ++++++++++++++++++++++++++++++
examples/watcher/wdt.c | 162 +++++++++++++++++++++
examples/watcher/wdt.h | 59 ++++++++
16 files changed, 1677 insertions(+)
diff --git a/examples/watched/Kconfig b/examples/watched/Kconfig
new file mode 100644
index 0000000..84a3db8
--- /dev/null
+++ b/examples/watched/Kconfig
@@ -0,0 +1,35 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#
+
+config EXAMPLES_WATCHED
+ tristate "Watched example"
+ default y
+ depends on EXAMPLES_WATCHER
+ ---help---
+ This application works with the watcher example and plays
+ the role of the watched task. This process will create 2
+ watched tasks. These tasks will subscribe to be watched.
+ One task will feed the dog and the other will starve the dog.
+ So, the watchdog timer will expire and the offending task will
+ be printed.
+
+if EXAMPLES_WATCHED
+
+config EXAMPLES_WATCHED_PROGNAME
+ string "Program name"
+ default "watched"
+ ---help---
+ This is the name of the program that will be used when the NSH
ELF
+ program is installed.
+
+config EXAMPLES_WATCHED_PRIORITY
+ int "Watched task priority"
+ default 100
+
+config EXAMPLES_WATCHED_STACKSIZE
+ int "Watched stack size"
+ default DEFAULT_TASK_STACKSIZE
+
+endif
diff --git a/examples/watched/Make.defs b/examples/watched/Make.defs
new file mode 100644
index 0000000..62edd87
--- /dev/null
+++ b/examples/watched/Make.defs
@@ -0,0 +1,24 @@
+############################################################################
+# apps/examples/watched/Make.defs
+# Adds selected applications to apps/ build
+#
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements. See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership. The
+# ASF licenses this file to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance with the
+# License. You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+#
+############################################################################/
+
+ifneq ($(CONFIG_EXAMPLES_WATCHED),)
+CONFIGURED_APPS += $(APPDIR)/examples/watched
+endif
diff --git a/examples/watched/Makefile b/examples/watched/Makefile
new file mode 100644
index 0000000..8df4cda
--- /dev/null
+++ b/examples/watched/Makefile
@@ -0,0 +1,35 @@
+############################################################################
+# examples/watched/Makefile
+#
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements. See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership. The
+# ASF licenses this file to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance with the
+# License. You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+#
+############################################################################/
+
+include $(APPDIR)/Make.defs
+
+# Watched built-in application info
+
+PROGNAME = $(CONFIG_EXAMPLES_WATCHED_PROGNAME)
+PRIORITY = $(CONFIG_EXAMPLES_WATCHED_PRIORITY)
+STACKSIZE = $(CONFIG_EXAMPLES_WATCHED_STACKSIZE)
+MODULE = $(CONFIG_EXAMPLES_WATCHED)
+
+# Watched Example
+
+CSRCS = watched.c
+MAINSRC = watched_main.c
+
+include $(APPDIR)/Application.mk
\ No newline at end of file
diff --git a/examples/watched/watched.c b/examples/watched/watched.c
new file mode 100644
index 0000000..87a66e9
--- /dev/null
+++ b/examples/watched/watched.c
@@ -0,0 +1,176 @@
+/****************************************************************************
+ * examples/watched/watched.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include "watched.h"
+#include <signal.h>
+
+/****************************************************************************
+ * Private Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+static struct watcher_info_s g_watcher_info =
+{
+ .watcher_pid = -1,
+ .info_file_name = "/mnt/watcher/info.txt"
+};
+
+/****************************************************************************
+ * Public Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+bool watched_is_watcher_on(void)
+{
+ FILE *fp;
+
+ /* Check if the watcher has already been initialized */
+
+ fp = fopen(g_watcher_info.info_file_name, "r");
+ if (fp)
+ {
+ fclose(fp);
+ return true;
+ }
+ else
+ {
+ return false;
+ }
+}
+
+int watched_read_watcher_info(struct watched_info_s *info)
+{
+ int ret = OK;
+ int watched_pid = getpid();
+ FILE *fp;
+
+ /* Load Watcher Info in case it was not loaded yet */
+
+ if (g_watcher_info.watcher_pid < 0)
+ {
+ /* Reading watcher value from file */
+
+ fp = fopen(g_watcher_info.info_file_name, "r");
+ if (fp == NULL)
+ {
+ int errcode = errno;
+ fprintf(stderr, "ERROR: Failed to open %s: %d\n",
+ g_watcher_info.info_file_name, errcode);
+ ret = errcode;
+ goto errout;
+ }
+
+ fscanf(fp, "%d %d %d %d %d", (int *)&(g_watcher_info.watcher_pid),
+ &(g_watcher_info.signal), &(g_watcher_info.sub_cmd),
+ &(g_watcher_info.feed_cmd), &(g_watcher_info.unsub_cmd));
+
+ fclose(fp);
+ }
+
+ /* Initialize Wacthed Info */
+
+ info->sub_request.task_id = watched_pid;
+ info->sub_request.code = g_watcher_info.sub_cmd;
+ info->sub_value.sival_ptr = &(info->sub_request);
+
+ info->unsub_request.task_id = watched_pid;
+ info->unsub_request.code = g_watcher_info.unsub_cmd;
+ info->unsub_value.sival_ptr = &(info->unsub_request);
+
+ info->feed_request.task_id = watched_pid;
+ info->feed_request.code = g_watcher_info.feed_cmd;
+ info->feed_value.sival_ptr = &(info->feed_request);
+
+errout:
+ return ret;
+}
+
+int watched_subscribe(struct watched_info_s *info)
+{
+ int ret;
+
+ /* Signal watcher = Request to subscribe */
+
+ ret =
+ sigqueue(g_watcher_info.watcher_pid, g_watcher_info.signal,
+ info->sub_value);
+ if (ret == ERROR)
+ {
+ int errcode = errno;
+ fprintf(stderr, "subscribe: error %d\n", errcode);
+ ret = errcode;
+ }
+
+ return ret;
+}
+
+int watched_unsubscribe(struct watched_info_s *info)
+{
+ int ret;
+
+ /* Signal watcher = Request to unsubscribe */
+
+ ret =
+ sigqueue(g_watcher_info.watcher_pid, g_watcher_info.signal,
+ info->unsub_value);
+ if (ret == ERROR)
+ {
+ int errcode = errno;
+ fprintf(stderr, "unsubscribe: error %d\n", errcode);
+ ret = errcode;
+ }
+
+ return ret;
+}
+
+int feed_dog(struct watched_info_s *info)
+{
+ int ret;
+
+ /* Signal watcher = Request to feed the dog */
+
+ ret =
+ sigqueue(g_watcher_info.watcher_pid, g_watcher_info.signal,
+ info->feed_value);
+ if (ret == ERROR)
+ {
+ int errcode = errno;
+ fprintf(stderr, "feed_dog: error %d\n", errcode);
+ ret = errcode;
+ }
+
+ return ret;
+}
diff --git a/examples/watched/watched.h b/examples/watched/watched.h
new file mode 100644
index 0000000..6cc1973
--- /dev/null
+++ b/examples/watched/watched.h
@@ -0,0 +1,79 @@
+/****************************************************************************
+ * examples/watched/watched.h
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+#ifndef __EXAMPLES_WATCHER_WATCHED_H
+#define __EXAMPLES_WATCHER_WATCHED_H
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+#include <signal.h>
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Types
+ ****************************************************************************/
+
+struct watcher_info_s
+{
+ int sub_cmd;
+ int unsub_cmd;
+ int feed_cmd;
+ int signal;
+ pid_t watcher_pid;
+ const char info_file_name[];
+};
+
+struct request_s
+{
+ pid_t task_id;
+ volatile int code;
+};
+
+struct watched_info_s
+{
+ struct request_s sub_request;
+ struct request_s unsub_request;
+ struct request_s feed_request;
+ union sigval sub_value;
+ union sigval unsub_value;
+ union sigval feed_value;
+};
+
+/****************************************************************************
+ * Public Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Function Prototypes
+ ****************************************************************************/
+
+bool watched_is_watcher_on(void);
+int watched_read_watcher_info(struct watched_info_s *info);
+int watched_subscribe(struct watched_info_s *info);
+int watched_unsubscribe(struct watched_info_s *info);
+int feed_dog(struct watched_info_s *info);
+
+#endif /* __EXAMPLES_WATCHER_WATCHED_H */
diff --git a/examples/watched/watched_main.c b/examples/watched/watched_main.c
new file mode 100644
index 0000000..76fee41
--- /dev/null
+++ b/examples/watched/watched_main.c
@@ -0,0 +1,180 @@
+/****************************************************************************
+ * examples/watched/watched_main.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+#include <stdio.h>
+#include <errno.h>
+#include <stdlib.h>
+#include "watched.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: Task that feeds the dog
+ ****************************************************************************/
+
+static int task1(int argc, FAR char *argv[])
+{
+ struct watched_info_s watched_info;
+
+ /* Get the necessary information from watcher */
+
+ watched_read_watcher_info(&watched_info);
+
+ watched_subscribe(&watched_info);
+
+ for (; ; )
+ {
+ feed_dog(&watched_info);
+ sleep(3);
+ }
+
+ return OK;
+}
+
+/****************************************************************************
+ * Name: Task that doesn't feed the dog
+ ****************************************************************************/
+
+static int task2(int argc, FAR char *argv[])
+{
+ int counter = 0;
+ struct watched_info_s watched_info;
+
+ /* Get the necessary information from watcher */
+
+ watched_read_watcher_info(&watched_info);
+
+ watched_subscribe(&watched_info);
+
+ for (; ; )
+ {
+ sleep((CONFIG_EXAMPLES_WATCHER_TIMEOUT) / 1000);
+ counter++;
+ if (counter == 5)
+ {
+ watched_unsubscribe(&watched_info);
+ }
+ }
+
+ return OK;
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: null_main
+ ****************************************************************************/
+
+int main(int argc, char *argv[])
+{
+ int ret = OK;
+
+ /* Check if the watcher has already been initialized */
+
+ if (!watched_is_watcher_on())
+ {
+ printf("Please, enable the watcher service \
+ before subscribing tasks!\n");
+ ret = ENOENT;
+ goto errout;
+ }
+
+ printf("Starting watched tasks\n");
+
+ /* Starting Tasks Tasks 1 and 4 will subscribe, but they will not feed the
+ * dog. Tasks 2 and 3 will subscribe and will feed the dog each 3 secs.
+ */
+
+ printf("Creating Watched Task 1 - It will not feed the dog\n");
+
+ ret = task_create("Watched Task 1", CONFIG_EXAMPLES_WATCHED_PRIORITY,
+ CONFIG_EXAMPLES_WATCHED_STACKSIZE, task2, NULL);
+ if (ret < 0)
+ {
+ int errcode = errno;
+ printf("watched_main: ERROR: Failed to start Watched Task 1: %d\n",
+ errcode);
+ ret = errcode;
+ goto errout;
+ }
+
+ printf("Creating Watched Task 2 - It will feed the dog\n");
+
+ ret = task_create("Watched Task 2", CONFIG_EXAMPLES_WATCHED_PRIORITY,
+ CONFIG_EXAMPLES_WATCHED_STACKSIZE, task1, NULL);
+ if (ret < 0)
+ {
+ int errcode = errno;
+ printf("watched_main: ERROR: Failed to start Watched Task 2: %d\n",
+ errcode);
+ ret = errcode;
+ goto errout;
+ }
+
+ printf("Creating Watched Task 3 - It will feed the dog\n");
+
+ ret = task_create("Watched Task 3", CONFIG_EXAMPLES_WATCHED_PRIORITY,
+ CONFIG_EXAMPLES_WATCHED_STACKSIZE, task1, NULL);
+ if (ret < 0)
+ {
+ int errcode = errno;
+ printf("watched_main: ERROR: Failed to start Watched Task 3: %d\n",
+ errcode);
+ ret = errcode;
+ goto errout;
+ }
+
+ printf("Creating Watched Task 4 - It will not feed the dog\n");
+
+ ret = task_create("Watched Task 4", CONFIG_EXAMPLES_WATCHED_PRIORITY,
+ CONFIG_EXAMPLES_WATCHED_STACKSIZE, task2, NULL);
+ if (ret < 0)
+ {
+ int errcode = errno;
+ printf("watched_main: ERROR: Failed to start Watched Task 4: %d\n",
+ errcode);
+ ret = errcode;
+ goto errout;
+ }
+
+errout:
+ return ret;
+}
diff --git a/examples/watcher/Kconfig b/examples/watcher/Kconfig
new file mode 100644
index 0000000..ffedde7
--- /dev/null
+++ b/examples/watcher/Kconfig
@@ -0,0 +1,49 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#
+
+config EXAMPLES_WATCHER
+ tristate "Watcher example"
+ default n
+ ---help---
+ Enable the watcher example. The watcher is a task that will
monitor
+ other tasks that have previously subscribed to be watched. If
the
+ watched tasks don't signal the watcher during the watchdog time
period,
+ the watchdog timer will expire and the watcher will print the
tasks that
+ did not signal and the ones that signaled. This example will
only be supported
+ by the chips that supports interrupt on timeout, i.e., which
have the \"capture\"
+ command implemented.
+
+if EXAMPLES_WATCHER
+
+config EXAMPLES_WATCHER_PROGNAME
+ string "Program name"
+ default "watcher"
+ ---help---
+ This is the name of the program that will be used when the NSH
ELF
+ program is installed.
+
+config EXAMPLES_WATCHER_PRIORITY
+ int "Watcher task priority"
+ default 100
+
+config EXAMPLES_WATCHER_STACKSIZE
+ int "Watcher stack size"
+ default DEFAULT_TASK_STACKSIZE
+
+config EXAMPLES_WATCHER_DEVPATH
+ string "Watchdog device path"
+ default "/dev/watchdog0"
+
+config EXAMPLES_WATCHER_TIMEOUT
+ int "Watchdog timeout in ms"
+ default 5000
+
+config EXAMPLES_WATCHER_SIGNAL
+ int "Signal Number for communication"
+ default 17
+ ---help---
+ This is the Signal Number used for communication between the
watcher task and the watched tasks.
+
+endif
diff --git a/examples/watcher/Make.defs b/examples/watcher/Make.defs
new file mode 100644
index 0000000..0b60529
--- /dev/null
+++ b/examples/watcher/Make.defs
@@ -0,0 +1,23 @@
+############################################################################
+# apps/examples/watcher/Make.defs
+#
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements. See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership. The
+# ASF licenses this file to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance with the
+# License. You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+#
+############################################################################
+
+ifneq ($(CONFIG_EXAMPLES_WATCHER),)
+CONFIGURED_APPS += $(APPDIR)/examples/watcher
+endif
diff --git a/examples/watcher/Makefile b/examples/watcher/Makefile
new file mode 100644
index 0000000..da58627
--- /dev/null
+++ b/examples/watcher/Makefile
@@ -0,0 +1,35 @@
+############################################################################
+# apps/examples/watcher/Make.defs
+#
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements. See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership. The
+# ASF licenses this file to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance with the
+# License. You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+#
+############################################################################
+
+include $(APPDIR)/Make.defs
+
+# Watcher built-in application info
+
+PROGNAME = $(CONFIG_EXAMPLES_WATCHER_PROGNAME)
+PRIORITY = $(CONFIG_EXAMPLES_WATCHER_PRIORITY)
+STACKSIZE = $(CONFIG_EXAMPLES_WATCHER_STACKSIZE)
+MODULE = $(CONFIG_EXAMPLES_WATCHER)
+
+# Watcher Example
+
+CSRCS = ramdisk.c wdt.c task_mn.c
+MAINSRC = watcher_main.c
+
+include $(APPDIR)/Application.mk
diff --git a/examples/watcher/ramdisk.c b/examples/watcher/ramdisk.c
new file mode 100644
index 0000000..346bf9c
--- /dev/null
+++ b/examples/watcher/ramdisk.c
@@ -0,0 +1,138 @@
+/****************************************************************************
+ * examples/watcher/ramdisk.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <sys/boardctl.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <sys/mount.h>
+#include <nuttx/drivers/ramdisk.h>
+
+#include "fsutils/mkfatfs.h"
+#include "ramdisk.h"
+
+/****************************************************************************
+ * Private Definitions
+ ****************************************************************************/
+
+#define BUFFER_SIZE \
+ (NSECTORS * SECTORSIZE)
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+static struct fat_format_s g_fmt = FAT_FORMAT_INITIALIZER;
+
+/****************************************************************************
+ * Public Data
+ ****************************************************************************/
+
+static const char g_source[] = MOUNT_DEVNAME;
+static const char g_filesystemtype[] = "vfat";
+static const char g_target[] = "/mnt/watcher";
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: create_ramdisk
+ *
+ * Description:
+ * Create a RAM disk of the specified size formatting with a FAT file
+ * system
+ *
+ * Input Parameters:
+ * None
+ *
+ * Return:
+ * Zero on success, a negated errno on failure.
+ *
+ ****************************************************************************/
+
+int create_ramdisk(void)
+{
+ struct boardioc_mkrd_s desc;
+ int ret;
+
+ /* Create a RAMDISK device to manage */
+
+ desc.minor = MINOR; /* Minor device number
of the RAM disk. */
+ desc.nsectors = NSECTORS; /* The number of
sectors in the RAM disk. */
+ desc.sectsize = SECTORSIZE; /* The size of one
sector in bytes. */
+ desc.rdflags = RDFLAG_WRENABLED | RDFLAG_FUNLINK; /* See ramdisk.h. */
+
+ ret = boardctl(BOARDIOC_MKRD, (uintptr_t) & desc);
+ if (ret < 0)
+ {
+ printf("create_ramdisk: Failed to create ramdisk at %s: %d\n",
+ g_source, -ret);
+ return ret;
+ }
+
+ /* Create a FAT filesystem on the ramdisk */
+
+ ret = mkfatfs(g_source, &g_fmt);
+ if (ret < 0)
+ {
+ printf("mkfatfs: Failed to create FAT filesystem on ramdisk at %s\n",
+ g_source);
+ return ret;
+ }
+
+ return 0;
+}
+
+int prepare_fs(void)
+{
+ int ret;
+ ret = create_ramdisk();
+ if (ret < 0)
+ {
+ int errcode = errno;
+ fprintf(stderr,
+ "create_ramdisk: failed on creating RAM disk \
+ and formatting it: %d\n",
+ errcode);
+ ret = errcode;
+ goto errout;
+ }
+
+ ret = mount(g_source, g_target, g_filesystemtype, 0, NULL);
+ if (ret < 0)
+ {
+ int errcode = errno;
+ fprintf(stderr, "mount: Failed to mount FS: %d\n", errcode);
+ ret = errcode;
+ goto errout;
+ }
+
+errout:
+ return ret;
+}
diff --git a/examples/watcher/ramdisk.h b/examples/watcher/ramdisk.h
new file mode 100644
index 0000000..bab2841
--- /dev/null
+++ b/examples/watcher/ramdisk.h
@@ -0,0 +1,56 @@
+/****************************************************************************
+ * examples/watcher/ramdisk.h
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+#ifndef __EXAMPLES_WATCHER_RAMDISK_H
+#define __EXAMPLES_WATCHER_RAMDISK_H
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+#define NSECTORS 64
+#define SECTORSIZE 512
+#define MINOR 0
+#define STR_MACRO(m) #m
+#define MKMOUNT_DEVNAME(m) "/dev/ram" STR_MACRO(m)
+#define MOUNT_DEVNAME MKMOUNT_DEVNAME(MINOR)
+
+/****************************************************************************
+ * Public Types
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Function Prototypes
+ ****************************************************************************/
+
+int create_ramdisk(void);
+int prepare_fs(void);
+
+#endif /* __EXAMPLES_WATCHER_RAMDISK_H */
diff --git a/examples/watcher/task_mn.c b/examples/watcher/task_mn.c
new file mode 100644
index 0000000..8ba7527
--- /dev/null
+++ b/examples/watcher/task_mn.c
@@ -0,0 +1,313 @@
+/****************************************************************************
+ * examples/watcher/task_mn.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+#include <sys/boardctl.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+#include <nuttx/note/noteram_driver.h>
+#include "task_mn.h"
+
+/****************************************************************************
+ * Private Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Data
+ ****************************************************************************/
+
+volatile struct request_s request;
+struct task_list_s watched_tasks =
+{
+ .head = NULL,
+ .tail = NULL
+};
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+void task_mn_print_tasks_status(void)
+{
+ int notefd;
+ struct noteram_get_taskname_s task;
+ struct task_node_s *node;
+
+ /* If the list is not empty */
+
+ if (watched_tasks.head != NULL)
+ {
+ /* Open the note driver */
+
+ notefd = open("/dev/note", O_RDONLY);
+ if (notefd < 0)
+ {
+ fprintf(stderr, "trace: cannot open /dev/note\n");
+ return;
+ }
+
+ /* Print all the nodes */
+
+ for (node = watched_tasks.head; node != NULL; node = node->next)
+ {
+ task.pid = node->task_id;
+ ioctl(notefd, NOTERAM_GETTASKNAME, (unsigned long)&task);
+ printf("%s ", task.taskname);
+ if (node->reset)
+ {
+ printf("fed the dog.\n");
+ }
+ else
+ {
+ printf("starved the dog.\n");
+ }
+ }
+
+ /* Close the note driver */
+
+ close(notefd);
+ }
+ else
+ {
+ fprintf(stderr, "watcher: List is empty to print\n");
+ }
+}
+
+void task_mn_reset_all(void)
+{
+ struct task_node_s *node;
+
+ for (node = watched_tasks.head; node != NULL; node = node->next)
+ {
+ node->reset = false;
+ }
+}
+
+struct task_node_s *task_mn_is_task_subscribed(pid_t id)
+{
+ struct task_node_s *node;
+
+ /* If list is not empty */
+
+ if (watched_tasks.head != NULL)
+ {
+ /* Search for the node */
+
+ for (node = watched_tasks.head; node != NULL; node = node->next)
+ {
+ if (node->task_id == id)
+ {
+ return node;
+ }
+ }
+ }
+
+ return NULL;
+}
+
+void task_mn_add_to_list(pid_t id)
+{
+ struct task_node_s *node;
+
+ /* Alloc the node */
+
+ node = malloc(sizeof(struct task_node_s));
+ if (node == NULL)
+ {
+ fprintf(stderr, "watcher daemon: Couldn't alloc a node to list\n");
+ return;
+ }
+
+ node->task_id = id;
+
+ /* NOTE: Once a task is subscribed, its initial status is that it fed the
+ * dog. This approach was used first to avoid a false-positive result,
+ * e.g., the task has been subscribed immediately before the watchdog
+ * expiration and it did not feed the dog within this interval,
+ * so the wdt handler would be triggered even if the subscribed
+ * task would feed the dog in time.
+ * The second reason is that we can consider the subscription request
+ * itself an advertisement that the watched task is alive and not stuck.
+ */
+
+ node->reset = true;
+ node->next = NULL;
+
+ /* If list is not empty */
+
+ if (watched_tasks.head != NULL)
+ {
+ watched_tasks.tail->next = node;
+ }
+ else
+ {
+ watched_tasks.head = node;
+ }
+
+ watched_tasks.tail = node;
+}
+
+void task_mn_remove_from_list(pid_t id)
+{
+ struct task_node_s *prev;
+ struct task_node_s *current;
+
+ /* If list is empty */
+
+ if (watched_tasks.head == NULL)
+ {
+ fprintf(stderr, "watcher daemon: List is empty\n");
+ return;
+ }
+
+ /* First element */
+
+ else if (watched_tasks.head->task_id == id)
+ {
+ if (watched_tasks.head == watched_tasks.tail)
+ {
+ free(watched_tasks.head);
+ watched_tasks.head = NULL;
+ watched_tasks.tail = NULL;
+ return;
+ }
+ else
+ {
+ prev = watched_tasks.head;
+ watched_tasks.head = prev->next;
+ free(prev);
+ return;
+ }
+ }
+ else
+ {
+ /* Search the node */
+
+ prev = watched_tasks.head;
+ current = prev->next;
+ while (current != NULL)
+ {
+ if (current->task_id == id)
+ {
+ prev->next = current->next;
+
+ /* In case the one that will be removed is the tail */
+
+ if (prev->next == NULL)
+ {
+ watched_tasks.tail = prev;
+ }
+
+ free(current);
+ return;
+ }
+
+ prev = prev->next;
+ current = current->next;
+ }
+ }
+
+ fprintf(stderr, "watcher daemon: This node is not in the list.\n");
+}
+
+void task_mn_get_task_name(struct noteram_get_taskname_s *task)
+{
+ int notefd;
+
+ notefd = open("/dev/note", O_RDONLY);
+ if (notefd < 0)
+ {
+ fprintf(stderr, "trace: cannot open /dev/note\n");
+ return;
+ }
+
+ ioctl(notefd, NOTERAM_GETTASKNAME, (unsigned long)task);
+ close(notefd);
+}
+
+void task_mn_subscribe(pid_t id)
+{
+ struct noteram_get_taskname_s task;
+
+ /* Verify if the task exists in the list */
+
+ if (task_mn_is_task_subscribed(id) != NULL)
+ {
+ task.pid = id;
+ task_mn_get_task_name(&task);
+ printf("Task %s was already subscribed\n", task.taskname);
+ }
+ else
+ {
+ /* If it doesn't, include it to the list */
+
+ task_mn_add_to_list(id);
+ }
+}
+
+void task_mn_unsubscribe(pid_t id)
+{
+ struct noteram_get_taskname_s task;
+
+ /* Verify if the task exists in the list */
+
+ if (task_mn_is_task_subscribed(id) != NULL)
+ {
+ /* If it does, remove it from the list */
+
+ task_mn_remove_from_list(id);
+ }
+ else
+ {
+ task.pid = id;
+ task_mn_get_task_name(&task);
+ printf("Task %s is not subscribed\n", task.taskname);
+ }
+}
+
+bool task_mn_all_tasks_fed(void)
+{
+ struct task_node_s *node;
+
+ for (node = watched_tasks.head; node != NULL; node = node->next)
+ {
+ /* If at least one did not feed the dog, return false */
+
+ if (node->reset == false)
+ {
+ return false;
+ }
+ }
+
+ return true;
+}
diff --git a/examples/watcher/task_mn.h b/examples/watcher/task_mn.h
new file mode 100644
index 0000000..a2daa07
--- /dev/null
+++ b/examples/watcher/task_mn.h
@@ -0,0 +1,79 @@
+/****************************************************************************
+ * examples/watcher/task_mn.h
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+#ifndef __EXAMPLES_WATCHER_TASK_MN_H
+#define __EXAMPLES_WATCHER_TASK_MN_H
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+#include <nuttx/note/noteram_driver.h>
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Types
+ ****************************************************************************/
+
+struct request_s
+{
+ pid_t task_id;
+ int code;
+};
+
+struct task_node_s
+{
+ pid_t task_id;
+ bool reset;
+ struct task_node_s *next;
+};
+
+struct task_list_s
+{
+ struct task_node_s *head;
+ struct task_node_s *tail;
+};
+
+/****************************************************************************
+ * Public Data
+ ****************************************************************************/
+
+extern volatile struct request_s request;
+extern struct task_list_s watched_tasks;
+
+/****************************************************************************
+ * Public Function Prototypes
+ ****************************************************************************/
+
+void task_mn_print_tasks_status(void);
+void task_mn_reset_all(void);
+struct task_node_s *task_mn_is_task_subscribed(pid_t id);
+void task_mn_add_to_list(pid_t id);
+void task_mn_remove_from_list(pid_t id);
+void task_mn_get_task_name(struct noteram_get_taskname_s *task);
+void task_mn_subscribe(pid_t id);
+void task_mn_unsubscribe(pid_t id);
+bool task_mn_all_tasks_fed(void);
+
+#endif /* __EXAMPLES_WATCHER_TASK_MN_H */
diff --git a/examples/watcher/watcher_main.c b/examples/watcher/watcher_main.c
new file mode 100644
index 0000000..c62e859
--- /dev/null
+++ b/examples/watcher/watcher_main.c
@@ -0,0 +1,234 @@
+/****************************************************************************
+ * examples/watcher/watcher_main.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+#include <stdio.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <sched.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+#include "ramdisk.h"
+#include "wdt.h"
+#include "task_mn.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+#define SUBSCRIBE_CMD 1
+#define UNSUSBCRIBE_CMD -1
+#define FEED_CMD 2
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+static const char g_info_file_name[] = "/mnt/watcher/info.txt";
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+static void feed_sighandler(int signo, FAR siginfo_t * siginfo,
+ FAR void *context)
+{
+ struct task_node_s *node;
+ request = *(struct request_s *)siginfo->si_value.sival_ptr;
+
+ switch (request.code)
+ {
+ case FEED_CMD:
+
+ /* Update the current requester task status */
+
+ node = task_mn_is_task_subscribed(request.task_id);
+ if (node != NULL)
+ {
+ node->reset = true;
+ }
+ else
+ {
+ fprintf(stderr,
+ "watcher daemon: task is not subscribed to feed dog.\n");
+ }
+
+ /* Verify if all tasks requested to feed the dog */
+
+ if (task_mn_all_tasks_fed())
+ {
+ /* If all tasks required, reset it and reset all tasks' status" */
+
+ wdt_feed_the_dog();
+ task_mn_reset_all();
+ }
+
+ break;
+ case SUBSCRIBE_CMD:
+
+ /* Include the current requester task to the watched tasks list */
+
+ task_mn_subscribe(request.task_id);
+ break;
+ case UNSUSBCRIBE_CMD:
+
+ /* Excludes the current requester task from the watched tasks list */
+
+ task_mn_unsubscribe(request.task_id);
+
+ /* Verify if all tasks has already requested to feed the dog in this
+ * round. Because maybe the watcher was only expecting the task that
+ * was unsubscribed to finally reset the dog.
+ * If this task is no longer being watched and the others have already
+ * sent a feed request, so it's time to feed the dog.
+ */
+
+ if (task_mn_all_tasks_fed())
+ {
+ /* If all tasks required, reset it and reset all tasks' status" */
+
+ wdt_feed_the_dog();
+ task_mn_reset_all();
+ }
+ break;
+ default:
+ fprintf(stderr, "watcher daemon: Invalid command\n");
+ }
+}
+
+/****************************************************************************
+ * Name: watcher_daemon
+ ****************************************************************************/
+
+static int watcher_daemon(int argc, FAR char *argv[])
+{
+ int ret;
+ struct sigaction act;
+ pid_t watcher_pid;
+ FILE *fp;
+
+ printf("Watcher Daemon has started!\n");
+
+ /* Configuring a signal action */
+
+ act.sa_sigaction = feed_sighandler; /* The handler to be triggered when
+ * receiving a signal */
+ act.sa_flags = SA_SIGINFO; /* Invoke the signal-catching function
*/
+ sigfillset(&act.sa_mask);
+ sigdelset(&act.sa_mask, CONFIG_EXAMPLES_WATCHER_SIGNAL); /* Block all
+ * other
+ * signals less
+ * this one */
+
+ ret = sigaction(CONFIG_EXAMPLES_WATCHER_SIGNAL, &act, NULL);
+ if (ret != OK)
+ {
+ int errcode = errno;
+ fprintf(stderr, "ERROR: sigaction failed: %d\n", errcode);
+ ret = errcode;
+ goto errout;
+ }
+
+ /* Collecting the necessary information of the current task */
+
+ watcher_pid = getpid();
+
+ /* Writing PID, SIGNAL NUMBER, and COMMANDS' value to a file */
+
+ fp = fopen(g_info_file_name, "w+");
+ if (fp == NULL)
+ {
+ int errcode = errno;
+ fprintf(stderr, "ERROR: Failed to open %s: %d\n",
+ g_info_file_name, errcode);
+ ret = errcode;
+ goto errout;
+ }
+
+ fprintf(fp, "%d %d %d %d %d\n", (int)watcher_pid,
+ (int)CONFIG_EXAMPLES_WATCHER_SIGNAL, (int)SUBSCRIBE_CMD,
+ (int)FEED_CMD, (int)UNSUSBCRIBE_CMD);
+ fclose(fp);
+
+ /* Suspends the calling thread until delivery of a non-blocked signal. */
+
+ while (1)
+ {
+ pause();
+ }
+
+errout:
+ return ret;
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * watcher_main
+ ****************************************************************************/
+
+int main(int argc, FAR char *argv[])
+{
+ int ret;
+ FILE *fp;
+
+ /* Check if the watcher has already been initialized */
+
+ fp = fopen(g_info_file_name, "r");
+ if (fp)
+ {
+ fclose(fp);
+ printf("Watcher is already running.\n");
+ ret = EBUSY;
+ goto errout;
+ }
+
+ /* Create a RAMDISK device, format it and mount it */
+
+ prepare_fs();
+
+ /* Initialize and configure the wdt */
+
+ wdt_init();
+
+ /* Start Daemon */
+
+ ret = task_create("watcher_daemon", CONFIG_EXAMPLES_WATCHER_PRIORITY,
+ CONFIG_EXAMPLES_WATCHER_STACKSIZE, watcher_daemon, NULL);
+ if (ret < 0)
+ {
+ int errcode = errno;
+ printf("watcher_main: ERROR: Failed to start watcher_daemon: %d\n",
+ errcode);
+ ret = errcode;
+ goto errout;
+ }
+
+errout:
+ return ret;
+
+ return EXIT_SUCCESS;
+}
diff --git a/examples/watcher/wdt.c b/examples/watcher/wdt.c
new file mode 100644
index 0000000..d34cebd
--- /dev/null
+++ b/examples/watcher/wdt.c
@@ -0,0 +1,162 @@
+/****************************************************************************
+ * examples/watcher/wdt.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+#include <sys/boardctl.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+#include "wdt.h"
+#include "task_mn.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Definitions
+ ****************************************************************************/
+
+static int wdt_print_handler(int irq, FAR void *context, FAR void *arg);
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+static struct wdog_params_s wdog =
+{.timeout = CONFIG_EXAMPLES_WATCHER_TIMEOUT,
+ .handlers.oldhandler = NULL,
+ .handlers.newhandler = wdt_print_handler
+};
+
+/****************************************************************************
+ * Public Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: wdt_print_handler
+ *
+ ****************************************************************************/
+
+static int wdt_print_handler(int irq, FAR void *context, FAR void *arg)
+{
+ if (watched_tasks.head != NULL)
+ {
+ printf("*** Printing Tasks Status ***\n");
+ task_mn_print_tasks_status();
+ task_mn_reset_all();
+ }
+
+ return OK;
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+int wdt_init(void)
+{
+ int fd;
+ int ret;
+ strcpy(wdog.devname, CONFIG_EXAMPLES_WATCHER_DEVPATH);
+
+ /* Open the watchdog device for reading */
+
+ fd = open(wdog.devname, O_RDONLY);
+ if (fd < 0)
+ {
+ int errcode = errno;
+ printf("wdt_init: open %s failed: %d\n", wdog.devname, errcode);
+ ret = errcode;
+ goto errout;
+ }
+
+ /* Set the watchdog timeout */
+
+ ret = ioctl(fd, WDIOC_SETTIMEOUT, (unsigned long)wdog.timeout);
+ if (ret < 0)
+ {
+ int errcode = errno;
+ printf("wdt_init: ioctl(WDIOC_SETTIMEOUT) failed: %d\n", errcode);
+ ret = errcode;
+ goto errout;
+ }
+
+ /* Register the expiration callback to be triggered on timeout */
+
+ ret =
+ ioctl(fd, WDIOC_CAPTURE, (unsigned long)((uintptr_t) & (wdog.handlers)));
+ if (ret < 0)
+ {
+ int errcode = errno;
+ printf("wdt_init: ioctl(WDIOC_CAPTURE) failed: %d\n", errcode);
+ ret = errcode;
+ goto errout;
+ }
+
+ /* Then start the watchdog timer. */
+
+ ret = ioctl(fd, WDIOC_START, 0);
+ if (ret < 0)
+ {
+ int errcode = errno;
+ printf("wdt_init: ioctl(WDIOC_START) failed: %d\n", errcode);
+ ret = errcode;
+ goto errout;
+ }
+
+ close(fd);
+
+errout:
+ return ret;
+}
+
+void wdt_feed_the_dog(void)
+{
+ int fd;
+ int ret;
+
+ fd = open(wdog.devname, O_RDONLY);
+ if (fd < 0)
+ {
+ fprintf(stderr, "trace: cannot open %s\n", wdog.devname);
+ return;
+ }
+
+ ret = ioctl(fd, WDIOC_KEEPALIVE, 0);
+ if (ret < 0)
+ {
+ printf("watcher: ioctl(WDIOC_KEEPALIVE) failed: %d\n", ret);
+ }
+
+ close(fd);
+}
diff --git a/examples/watcher/wdt.h b/examples/watcher/wdt.h
new file mode 100644
index 0000000..95bc20e
--- /dev/null
+++ b/examples/watcher/wdt.h
@@ -0,0 +1,59 @@
+/****************************************************************************
+ * examples/watcher/wdt.h
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+#ifndef __EXAMPLES_WATCHER_WDT_H
+#define __EXAMPLES_WATCHER_WDT_H
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+#include <nuttx/timers/watchdog.h>
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+#define DEVNAME_SIZE 16
+
+/****************************************************************************
+ * Public Types
+ ****************************************************************************/
+
+struct wdog_params_s
+{
+ uint32_t timeout;
+ char devname[DEVNAME_SIZE];
+ struct watchdog_capture_s handlers;
+};
+
+/****************************************************************************
+ * Public Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Function Prototypes
+ ****************************************************************************/
+
+int wdt_init(void);
+void wdt_feed_the_dog(void);
+
+#endif /* __EXAMPLES_WATCHER_WDT_H */
