[PATCH v2 02/10] share/mainloop: Add watchdog support

[Luiz Augusto von Dentz <luiz.dentz@gmail.com>]

From: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

This adds watchdog notification support by sending "WATCHDOG=1" twice
as frequent as required by WATCHDOG_USEC.
---
 src/shared/mainloop-notify.c | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/src/shared/mainloop-notify.c b/src/shared/mainloop-notify.c
index 81b0e15ba..49ca4f6c9 100644
--- a/src/shared/mainloop-notify.c
+++ b/src/shared/mainloop-notify.c
@@ -37,13 +37,27 @@
 
 #include "mainloop.h"
 #include "mainloop-notify.h"
+#include "timeout.h"
+
+#define WATCHDOG_TRIGGER_FREQ 2
 
 static char *notify_sock;
 static int notify_fd = -1;
 
+static unsigned int watchdog;
+
+static bool watchdog_callback(void *user_data)
+{
+	mainloop_sd_notify("WATCHDOG=1");
+
+	return true;
+}
+
 void mainloop_notify_init(void)
 {
 	const char *sock;
+	const char *watchdog_usec;
+	int msec;
 
 	sock = getenv("NOTIFY_SOCKET");
 	if (!sock)
@@ -56,6 +70,17 @@ void mainloop_notify_init(void)
 	notify_sock = strdup(sock);
 
 	notify_fd = socket(AF_UNIX, SOCK_DGRAM | SOCK_CLOEXEC, 0);
+
+	watchdog_usec = getenv("WATCHDOG_USEC");
+	if (!watchdog_usec)
+		return;
+
+	msec = atoi(watchdog_usec) / 1000;
+	if (msec < 0)
+		return;
+
+	watchdog = timeout_add(msec / WATCHDOG_TRIGGER_FREQ,
+				watchdog_callback, NULL, NULL);
 }
 
 void mainloop_notify_exit(void)
@@ -67,6 +92,8 @@ void mainloop_notify_exit(void)
 
 	free(notify_sock);
 	notify_sock = NULL;
+
+	timeout_remove(watchdog);
 }
 
 int mainloop_sd_notify(const char *state)
-- 
2.17.2