event-loop: poll a signalfd to know when to quit

event-loop.c

@@ -4,13 +4,46 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <sys/timerfd.h>
+#include <signal.h>
+#include <sys/signalfd.h>
 #include <time.h>
 #include <unistd.h>
 
 #include "event-loop.h"
 
-void init_event_loop(struct mako_event_loop *loop, sd_bus *bus,
+static int init_signalfd() {
+	sigset_t mask;
+	int sfd;
+
+	sigemptyset(&mask);
+	sigaddset(&mask, SIGINT);
+	sigaddset(&mask, SIGTERM);
+	sigaddset(&mask, SIGQUIT);
+
+	if (sigprocmask(SIG_BLOCK, &mask, NULL) == -1) {
+		fprintf(stderr, "sigprocmask: %s", strerror(errno));
+		return -1;
+	}
+
+	if ((sfd = signalfd(-1, &mask, SFD_NONBLOCK)) == -1) {
+		fprintf(stderr, "signalfd: %s", strerror(errno));
+		return -1;
+	}
+
+	return sfd;
+}
+
+bool init_event_loop(struct mako_event_loop *loop, sd_bus *bus,
 		struct wl_display *display) {
+	if ((loop->sfd = init_signalfd()) == -1) {
+		return false;
+	}
+
+	loop->fds[MAKO_EVENT_SIGNAL] = (struct pollfd){
+		.fd = loop->sfd,
+		.events = POLLIN,
+	};
+
 	loop->fds[MAKO_EVENT_DBUS] = (struct pollfd){
 		.fd = sd_bus_get_fd(bus),
 		.events = POLLIN,
@@ -29,6 +62,8 @@ void init_event_loop(struct mako_event_loop *loop, sd_bus *bus,
 	loop->bus = bus;
 	loop->display = display;
 	wl_list_init(&loop->timers);
+
+	return true;
 }
 
 void finish_event_loop(struct mako_event_loop *loop) {
@@ -172,6 +207,10 @@ int run_event_loop(struct mako_event_loop *loop) {
 			break;
 		}
 
+		if (loop->fds[MAKO_EVENT_SIGNAL].revents & POLLIN) {
+			break;
+		}
+
 		if (!(loop->fds[MAKO_EVENT_WAYLAND].revents & POLLIN)) {
 			wl_display_cancel_read(loop->display);
 		}
@@ -211,14 +250,3 @@ int run_event_loop(struct mako_event_loop *loop) {
 	}
 	return ret;
 }
-
-static void handle_stop_event_loop_timer(void *data) {
-	// No-op
-}
-
-void stop_event_loop(struct mako_event_loop *loop) {
-	loop->running = false;
-
-	// Wake up the event loop
-	add_event_loop_timer(loop, 0, handle_stop_event_loop_timer, NULL);
-}

include/event-loop.h

@@ -11,13 +11,15 @@ enum mako_event {
 	MAKO_EVENT_DBUS,
 	MAKO_EVENT_WAYLAND,
 	MAKO_EVENT_TIMER,
+	MAKO_EVENT_SIGNAL,
 	MAKO_EVENT_COUNT, // keep last
 };
 
 struct mako_event_loop {
 	struct pollfd fds[MAKO_EVENT_COUNT];
 	sd_bus *bus;
 	struct wl_display *display;
+	int sfd;
 
 	bool running;
 	struct wl_list timers; // mako_timer::link
@@ -34,11 +36,10 @@ struct mako_timer {
 	struct wl_list link; // mako_event_loop::timers
 };
 
-void init_event_loop(struct mako_event_loop *loop, sd_bus *bus,
+bool init_event_loop(struct mako_event_loop *loop, sd_bus *bus,
 	struct wl_display *display);
 void finish_event_loop(struct mako_event_loop *loop);
 int run_event_loop(struct mako_event_loop *loop);
-void stop_event_loop(struct mako_event_loop *loop);
 struct mako_timer *add_event_loop_timer(struct mako_event_loop *loop,
 	int delay_ms, mako_event_loop_timer_func_t func, void *data);
 

main.c

@@ -1,6 +1,5 @@
 #define _POSIX_C_SOURCE 200809L
 #include <errno.h>
-#include <signal.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -45,7 +44,11 @@ static bool init(struct mako_state *state) {
 		finish_dbus(state);
 		return false;
 	}
-	init_event_loop(&state->event_loop, state->bus, state->display);
+	if (!init_event_loop(&state->event_loop, state->bus, state->display)) {
+		finish_dbus(state);
+		finish_wayland(state);
+		return false;
+	}
 	wl_list_init(&state->notifications);
 	return true;
 }
@@ -62,10 +65,6 @@ static void finish(struct mako_state *state) {
 
 static struct mako_event_loop *event_loop = NULL;
 
-static void handle_signal(int signum) {
-	stop_event_loop(event_loop);
-}
-
 int main(int argc, char *argv[]) {
 	struct mako_state state = {0};
 
@@ -89,9 +88,6 @@ int main(int argc, char *argv[]) {
 	}
 
 	event_loop = &state.event_loop;
-	struct sigaction sa = { .sa_handler = handle_signal };
-	sigaction(SIGINT, &sa, NULL);
-	sigaction(SIGTERM, &sa, NULL);
 
 	ret = run_event_loop(&state.event_loop);