Use wl_event_loop_add_signal for exit signals

This avoids calling non-async-signal-safe functions from within a signal
handler.

sway/main.c

@@ -44,10 +44,6 @@ void sway_terminate(int exit_code) {
 	}
 }
 
-void sig_handler(int signal) {
-	sway_terminate(EXIT_SUCCESS);
-}
-
 void run_as_ipc_client(char *command, char *socket_path) {
 	int socketfd = ipc_open_socket(socket_path);
 	uint32_t len = strlen(command);
@@ -152,6 +148,22 @@ void restore_nofile_limit(void) {
 	}
 }
 
+static int term_signal(int signal, void *data) {
+	sway_terminate(EXIT_SUCCESS);
+	return 0;
+}
+
+static void init_signals(void) {
+	wl_event_loop_add_signal(server.wl_event_loop, SIGTERM, term_signal, NULL);
+	wl_event_loop_add_signal(server.wl_event_loop, SIGINT, term_signal, NULL);
+
+	// avoid need to reap children
+	signal(SIGCHLD, SIG_IGN);
+
+	// prevent ipc write errors from crashing sway
+	signal(SIGPIPE, SIG_IGN);
+}
+
 void restore_signals(void) {
 	sigset_t set;
 	sigemptyset(&set);
@@ -330,22 +342,14 @@ int main(int argc, char **argv) {
 
 	increase_nofile_limit();
 
-	// handle SIGTERM signals
-	signal(SIGTERM, sig_handler);
-	signal(SIGINT, sig_handler);
-
-	// avoid need to reap children
-	signal(SIGCHLD, SIG_IGN);
-
-	// prevent ipc from crashing sway
-	signal(SIGPIPE, SIG_IGN);
-
 	sway_log(SWAY_INFO, "Starting sway version " SWAY_VERSION);
 
 	if (!server_init(&server)) {
 		return 1;
 	}
 
+	init_signals();
+
 	if (server.linux_dmabuf_v1) {
 		wlr_scene_set_linux_dmabuf_v1(root->root_scene, server.linux_dmabuf_v1);
 	}