Daemon: daemon_control() finished

[libucw.git] / ucw / daemon.h

diff --git a/ucw/daemon.h b/ucw/daemon.h
index c00f00d1a5762d5e79b1729bc685ed352e03f503..dc2fd746eb39342287293041b31c76f9a15f67be 100644 (file)
--- a/ucw/daemon.h
+++ b/ucw/daemon.h
@@ -12,6 +12,7 @@
 
 #include <sys/types.h>
 
+/** Parameters passed to the daemon helper. **/
 struct daemon_params {
   uns flags;                           // DAEMON_FLAG_xxx
   const char *pid_file;                        // A path to PID file (optional)
@@ -26,6 +27,7 @@ struct daemon_params {
   int pid_fd;
 };
 
+/** Flags passed to the daemon helper. **/
 enum daemon_flags {
   DAEMON_FLAG_PRESERVE_CWD = 1,                // Skip chdir("/")
 };
@@ -50,4 +52,48 @@ void daemon_run(struct daemon_params *dp, void (*body)(struct daemon_params *dp)
  **/
 void daemon_exit(struct daemon_params *dp);
 
+#define DAEMON_ERR_LEN 256
+
+/** Parameters passed to daemon_control() **/
+struct daemon_control_params {
+  const char *pid_file;                // A path to PID file
+  const char *guard_file;      // A path to guard file
+  int action;                  // Action to perform (DAEMON_CONTROL_xxx)
+  char * const *argv;          // Daemon's arguments, NULL-terminated (for DAEMON_CONTROL_START)
+  int signal;                  // Signal to send (for DAEMON_CONTROL_SIGNAL)
+  char error_msg[DAEMON_ERR_LEN];      // A detailed error message returned (for DAEMON_STATUS_ERROR)
+};
+
+enum daemon_control_action {
+  DAEMON_CONTROL_CHECK,
+  DAEMON_CONTROL_START,
+  DAEMON_CONTROL_STOP,
+  DAEMON_CONTROL_SIGNAL,
+};
+
+/**
+ * Perform an action on a daemon:
+ *
+ * * `DAEMON_CONTROL_START` to start the daemon
+ * * `DAEMON_CONTROL_STOP` to stop the daemon (send `SIGTERM` or `dc->signal` if non-zero)
+ * * `DAEMON_CONTROL_CHECK` to check that the daemon is running
+ * * `DAEMON_CONTROL_SIGNAL` to send a signal to the daemon
+ *
+ * The function returns a status code:
+ *
+ * * `DAEMON_STATUS_OK` if the action has been performed successfully
+ * * `DAEMON_STATUS_ALREADY_DONE` if the daemon is already in the requested state
+ * * `DAEMON_STATUS_NOT_RUNNING` if the action failed, because the daemon is not running
+ * * `DAEMON_STATUS_ERROR` if the action failed for some other reason (in this case,
+ *   `dc->error_msg` contains a full error message)
+ **/
+enum daemon_control_status daemon_control(struct daemon_control_params *dc);
+
+enum daemon_control_status {
+  DAEMON_STATUS_OK = 0,
+  DAEMON_STATUS_ALREADY_DONE = 100,
+  DAEMON_STATUS_NOT_RUNNING = 101,
+  DAEMON_STATUS_ERROR = 102,
+};
+
 #endif