improve launchd integration

3 files changed, 123 insertions, 19 deletions

diff --git a/src/log.h b/src/log.h
index 2e8167b..d3cf6f1 100644
--- a/src/log.h
+++ b/src/log.h
@@ -33,4 +33,14 @@ error(const char *format, ...)
     exit(EXIT_FAILURE);
 }
 
+static inline void
+require(const char *format, ...)
+{
+    va_list args;
+    va_start(args, format);
+    vfprintf(stderr, format, args);
+    va_end(args);
+    exit(EXIT_SUCCESS);
+}
+
 #endif
diff --git a/src/service.h b/src/service.h
index bb43e8e..ae97084 100644
--- a/src/service.h
+++ b/src/service.h
@@ -29,13 +29,16 @@
     "    <key>RunAtLoad</key>\n" \
     "    <true/>\n" \
     "    <key>KeepAlive</key>\n" \
-    "    <true/>\n" \
+    "    <dict>\n" \
+    "        <key>SuccessfulExit</key>\n" \
+    " 	     <false/>\n" \
+    " 	     <key>Crashed</key>\n" \
+    " 	     <true/>\n" \
+    "    </dict>\n" \
     "    <key>StandardOutPath</key>\n" \
     "    <string>/tmp/skhd_%s.out.log</string>\n" \
     "    <key>StandardErrorPath</key>\n" \
     "    <string>/tmp/skhd_%s.err.log</string>\n" \
-    "    <key>ThrottleInterval</key>\n" \
-    "    <integer>30</integer>\n" \
     "    <key>ProcessType</key>\n" \
     "    <string>Interactive</string>\n" \
     "    <key>Nice</key>\n" \
@@ -43,12 +46,27 @@
     "</dict>\n" \
     "</plist>"
 
-static bool file_exists(char *filename);
+//
+// NOTE(koekeishiya): A launchd service has the following states:
+//
+//          1. Installed / Uninstalled
+//          2. Active (Enable / Disable)
+//          3. Bootstrapped (Load / Unload)
+//          4. Running (Start / Stop)
+//
 
-static int safe_exec(char *const argv[])
+static int safe_exec(char *const argv[], bool suppress_output)
 {
     pid_t pid;
-    int status = posix_spawn(&pid, argv[0], NULL, NULL, argv, NULL);
+    posix_spawn_file_actions_t actions;
+    posix_spawn_file_actions_init(&actions);
+
+    if (suppress_output) {
+        posix_spawn_file_actions_addopen(&actions, STDOUT_FILENO, "/dev/null", O_WRONLY|O_APPEND, 0);
+        posix_spawn_file_actions_addopen(&actions, STDERR_FILENO, "/dev/null", O_WRONLY|O_APPEND, 0);
+    }
+
+    int status = posix_spawn(&pid, argv[0], &actions, NULL, argv, NULL);
     if (status) return 1;
 
     while ((waitpid(pid, &status, 0) == -1) && (errno == EINTR)) {
@@ -183,6 +201,8 @@ static int service_install_internal(char *skhd_plist_path)
     return result;
 }
 
+static bool file_exists(char *filename);
+
 static int service_install(void)
 {
     char *skhd_plist_path = populate_plist_path();
@@ -208,7 +228,6 @@ static int service_uninstall(void)
 static int service_start(void)
 {
     char *skhd_plist_path = populate_plist_path();
-
     if (!file_exists(skhd_plist_path)) {
         warn("skhd: service file '%s' is not installed! attempting installation..\n", skhd_plist_path);
 
@@ -218,35 +237,110 @@ static int service_start(void)
         }
     }
 
-    const char *const args[] = { _PATH_LAUNCHCTL, "load", "-w", skhd_plist_path, NULL };
-    return safe_exec((char *const*)args);
+    char service_target[MAXLEN];
+    snprintf(service_target, sizeof(service_target), "gui/%d/%s", getuid(), _NAME_SKHD_PLIST);
+
+    char domain_target[MAXLEN];
+    snprintf(domain_target, sizeof(domain_target), "gui/%d", getuid());
+
+    //
+    // NOTE(koekeishiya): Check if service is bootstrapped
+    //
+
+    const char *const args[] = { _PATH_LAUNCHCTL, "print", service_target, NULL };
+    int is_bootstrapped = safe_exec((char *const*)args, true);
+
+    if (is_bootstrapped != 0) {
+
+        //
+        // NOTE(koekeishiya): Service is not bootstrapped and could be disabled.
+        // There is no way to query if the service is disabled, and we cannot
+        // bootstrap a disabled service. Try to enable the service. This will be
+        // a no-op if the service is already enabled.
+        //
+
+        const char *const args[] = { _PATH_LAUNCHCTL, "enable", service_target, NULL };
+        safe_exec((char *const*)args, false);
+
+        //
+        // NOTE(koekeishiya): Bootstrap service into the target domain.
+        // This will also start the program **iff* RunAtLoad is set to true.
+        //
+
+        const char *const args2[] = { _PATH_LAUNCHCTL, "bootstrap", domain_target, skhd_plist_path, NULL };
+        return safe_exec((char *const*)args2, false);
+    } else {
+
+        //
+        // NOTE(koekeishiya): The service has already been bootstrapped.
+        // Tell the bootstrapped service to launch immediately; it is an
+        // error to bootstrap a service that has already been bootstrapped.
+        //
+
+        const char *const args[] = { _PATH_LAUNCHCTL, "kickstart", service_target, NULL };
+        return safe_exec((char *const*)args, false);
+    }
 }
 
 static int service_restart(void)
 {
     char *skhd_plist_path = populate_plist_path();
-
     if (!file_exists(skhd_plist_path)) {
         error("skhd: service file '%s' is not installed! abort..\n", skhd_plist_path);
     }
 
-    char skhd_service_id[MAXLEN];
-    snprintf(skhd_service_id, sizeof(skhd_service_id), "gui/%d/%s", getuid(), _NAME_SKHD_PLIST);
+    char service_target[MAXLEN];
+    snprintf(service_target, sizeof(service_target), "gui/%d/%s", getuid(), _NAME_SKHD_PLIST);
 
-    const char *const args[] = { _PATH_LAUNCHCTL, "kickstart", "-k", skhd_service_id, NULL };
-    return safe_exec((char *const*)args);
+    const char *const args[] = { _PATH_LAUNCHCTL, "kickstart", "-k", service_target, NULL };
+    return safe_exec((char *const*)args, false);
 }
 
 static int service_stop(void)
 {
     char *skhd_plist_path = populate_plist_path();
-
     if (!file_exists(skhd_plist_path)) {
         error("skhd: service file '%s' is not installed! abort..\n", skhd_plist_path);
     }
 
-    const char *const args[] = { _PATH_LAUNCHCTL, "unload", "-w", skhd_plist_path, NULL };
-    return safe_exec((char *const*)args);
+    char service_target[MAXLEN];
+    snprintf(service_target, sizeof(service_target), "gui/%d/%s", getuid(), _NAME_SKHD_PLIST);
+
+    char domain_target[MAXLEN];
+    snprintf(domain_target, sizeof(domain_target), "gui/%d", getuid());
+
+    //
+    // NOTE(koekeishiya): Check if service is bootstrapped
+    //
+
+    const char *const args[] = { _PATH_LAUNCHCTL, "print", service_target, NULL };
+    int is_bootstrapped = safe_exec((char *const*)args, true);
+
+    if (is_bootstrapped != 0) {
+
+        //
+        // NOTE(koekeishiya): Service is not bootstrapped, but the program
+        // could still be running an instance that was started **while the service
+        // was bootstrapped**, so we tell it to stop said service.
+        //
+
+        const char *const args[] = { _PATH_LAUNCHCTL, "kill", "SIGTERM", service_target, NULL };
+        return safe_exec((char *const*)args, false);
+    } else {
+
+        //
+        // NOTE(koekeishiya): Service is bootstrapped; we stop a potentially
+        // running instance of the program and unload the service, making it
+        // not trigger automatically in the future.
+        //
+        // This is NOT the same as disabling the service, which will prevent
+        // it from being boostrapped in the future (without explicitly re-enabling
+        // it first).
+        //
+
+        const char *const args[] = { _PATH_LAUNCHCTL, "bootout", domain_target, skhd_plist_path, NULL };
+        return safe_exec((char *const*)args, false);
+    }
 }
 
 #endif
diff --git a/src/skhd.c b/src/skhd.c
index 6da4456..b8f5c2f 100644
--- a/src/skhd.c
+++ b/src/skhd.c
@@ -459,7 +459,7 @@ static GLOBAL_CONNECTION_CALLBACK(connection_handler)
 int main(int argc, char **argv)
 {
     if (getuid() == 0 || geteuid() == 0) {
-        error("skhd: running as root is not allowed! abort..\n");
+        require("skhd: running as root is not allowed! abort..\n");
     }
 
     if (parse_arguments(argc, argv)) {
@@ -475,7 +475,7 @@ int main(int argc, char **argv)
     }
 
     if (!check_privileges()) {
-        error("skhd: must be run with accessibility access! abort..\n");
+        require("skhd: must be run with accessibility access! abort..\n");
     }
 
     if (!initialize_keycode_map()) {