Merge pull request #1835 from ascent12/swaybar_status_err

Swaybar fix

swaybar/bar.c

@@ -401,24 +401,28 @@ void bar_setup(struct swaybar *bar,
 	render_all_frames(bar);
 }
 
-static void display_in(int fd, short mask, void *_bar) {
-	struct swaybar *bar = (struct swaybar *)_bar;
+static void display_in(int fd, short mask, void *data) {
+	struct swaybar *bar = data;
 	if (wl_display_dispatch(bar->display) == -1) {
 		bar_teardown(bar);
 		exit(0);
 	}
 }
 
-static void ipc_in(int fd, short mask, void *_bar) {
-	struct swaybar *bar = (struct swaybar *)_bar;
+static void ipc_in(int fd, short mask, void *data) {
+	struct swaybar *bar = data;
 	if (handle_ipc_readable(bar)) {
 		render_all_frames(bar);
 	}
 }
 
-static void status_in(int fd, short mask, void *_bar) {
-	struct swaybar *bar = (struct swaybar *)_bar;
-	if (status_handle_readable(bar->status)) {
+static void status_in(int fd, short mask, void *data) {
+	struct swaybar *bar = data;
+	if (mask & (POLLHUP | POLLERR)) {
+		status_error(bar->status, "[error reading from status command]");
+		render_all_frames(bar);
+		remove_event(fd);
+	} else if (status_handle_readable(bar->status)) {
 		render_all_frames(bar);
 	}
 }

swaybar/event_loop.c

@@ -72,24 +72,18 @@ void add_event(int fd, short mask,
 }
 
 bool remove_event(int fd) {
-	int index = -1;
+	/*
+	 * Instead of removing events immediately, we mark them for deletion
+	 * and clean them up later. This is so we can call remove_event inside
+	 * an event callback safely.
+	 */
 	for (int i = 0; i < event_loop.fds.length; ++i) {
 		if (event_loop.fds.items[i].fd == fd) {
-			index = i;
+			event_loop.fds.items[i].fd = -1;
+			return true;
 		}
 	}
-	if (index != -1) {
-		free(event_loop.items->items[index]);
-
-		--event_loop.fds.length;
-		memmove(&event_loop.fds.items[index], &event_loop.fds.items[index + 1],
-				sizeof(struct pollfd) * event_loop.fds.length - index);
-
-		list_del(event_loop.items, index);
-		return true;
-	} else {
-		return false;
-	}
+	return false;
 }
 
 static int timer_item_timer_cmp(const void *_timer_item, const void *_timer) {
@@ -118,11 +112,29 @@ void event_loop_poll() {
 		struct pollfd pfd = event_loop.fds.items[i];
 		struct event_item *item = (struct event_item *)event_loop.items->items[i];
 
-		if (pfd.revents & pfd.events) {
+		// Always send these events
+		unsigned events = pfd.events | POLLHUP | POLLERR;
+
+		if (pfd.revents & events) {
 			item->cb(pfd.fd, pfd.revents, item->data);
 		}
 	}
 
+	// Cleanup removed events
+	int end = 0;
+	int length = event_loop.fds.length;
+	for (int i = 0; i < length; ++i) {
+		if (event_loop.fds.items[i].fd == -1) {
+			free(event_loop.items->items[i]);
+			list_del(event_loop.items, i);
+			--event_loop.fds.length;
+		} else if (end != i) {
+			event_loop.fds.items[end++] = event_loop.fds.items[i];
+		} else {
+			end = i + 1;
+		}
+	}
+
 	// check timers
 	// not tested, but seems to work
 	for (int i = 0; i < event_loop.timers->length; ++i) {