Merge pull request #627 from emersion/wlr-signal-emit-safe

Remove wlr_backend.events.{output_remove,device_remove} 

30 files changed, 225 insertions, 238 deletions

diff --git a/backend/backend.c b/backend/backend.c
index 98b94c5c..c67be617 100644
--- a/backend/backend.c
+++ b/backend/backend.c
@@ -1,17 +1,17 @@
-#include <wayland-server.h>
-#include <unistd.h>
-#include <stdlib.h>
-#include <string.h>
-#include <errno.h>
 #include <assert.h>
+#include <errno.h>
 #include <libinput.h>
-#include <wlr/backend/session.h>
-#include <wlr/backend/interface.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <wayland-server.h>
 #include <wlr/backend/drm.h>
+#include <wlr/backend/interface.h>
 #include <wlr/backend/libinput.h>
+#include <wlr/backend/multi.h>
+#include <wlr/backend/session.h>
 #include <wlr/backend/wayland.h>
 #include <wlr/backend/x11.h>
-#include <wlr/backend/multi.h>
 #include <wlr/util/log.h>
 
 void wlr_backend_init(struct wlr_backend *backend,
@@ -19,10 +19,8 @@ void wlr_backend_init(struct wlr_backend *backend,
 	assert(backend);
 	backend->impl = impl;
 	wl_signal_init(&backend->events.destroy);
-	wl_signal_init(&backend->events.input_add);
-	wl_signal_init(&backend->events.input_remove);
-	wl_signal_init(&backend->events.output_add);
-	wl_signal_init(&backend->events.output_remove);
+	wl_signal_init(&backend->events.new_input);
+	wl_signal_init(&backend->events.new_output);
 }
 
 bool wlr_backend_start(struct wlr_backend *backend) {
diff --git a/backend/drm/atomic.c b/backend/drm/atomic.c
index 526b2731..29b5ccb1 100644
--- a/backend/drm/atomic.c
+++ b/backend/drm/atomic.c
@@ -1,8 +1,8 @@
-#include <stdlib.h>
 #include <gbm.h>
+#include <stdlib.h>
+#include <wlr/util/log.h>
 #include <xf86drm.h>
 #include <xf86drmMode.h>
-#include <wlr/util/log.h>
 #include "backend/drm/drm.h"
 #include "backend/drm/iface.h"
 #include "backend/drm/util.h"
diff --git a/backend/drm/backend.c b/backend/drm/backend.c
index 3782817c..47dff227 100644
--- a/backend/drm/backend.c
+++ b/backend/drm/backend.c
@@ -1,18 +1,19 @@
-#include <unistd.h>
-#include <stdlib.h>
+#include <assert.h>
+#include <errno.h>
 #include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
-#include <errno.h>
-#include <assert.h>
+#include <unistd.h>
 #include <wayland-server.h>
-#include <xf86drm.h>
-#include <wlr/backend/session.h>
 #include <wlr/backend/interface.h>
+#include <wlr/backend/session.h>
 #include <wlr/interfaces/wlr_output.h>
+#include <wlr/render/egl.h>
 #include <wlr/types/wlr_list.h>
 #include <wlr/util/log.h>
-#include <wlr/render/egl.h>
+#include <xf86drm.h>
 #include "backend/drm/drm.h"
+#include "util/signal.h"
 
 static bool wlr_drm_backend_start(struct wlr_backend *backend) {
 	struct wlr_drm_backend *drm = (struct wlr_drm_backend *)backend;
@@ -34,7 +35,7 @@ static void wlr_drm_backend_destroy(struct wlr_backend *backend) {
 		wlr_output_destroy(&conn->output);
 	}
 
-	wl_signal_emit(&backend->events.destroy, backend);
+	wlr_signal_emit_safe(&backend->events.destroy, backend);
 
 	wl_list_remove(&drm->display_destroy.link);
 	wl_list_remove(&drm->session_signal.link);
diff --git a/backend/drm/drm.c b/backend/drm/drm.c
index 56a78851..e60b7e1c 100644
--- a/backend/drm/drm.c
+++ b/backend/drm/drm.c
@@ -1,29 +1,30 @@
 #include <assert.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <inttypes.h>
-#include <errno.h>
-#include <time.h>
-#include <xf86drm.h>
-#include <xf86drmMode.h>
 #include <drm_mode.h>
 #include <EGL/egl.h>
 #include <EGL/eglext.h>
+#include <errno.h>
 #include <gbm.h>
 #include <GLES2/gl2.h>
 #include <GLES2/gl2ext.h>
+#include <inttypes.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
 #include <wayland-server.h>
 #include <wayland-util.h>
 #include <wlr/backend/interface.h>
 #include <wlr/interfaces/wlr_output.h>
-#include <wlr/util/log.h>
-#include <wlr/render/matrix.h>
-#include <wlr/render/gles2.h>
 #include <wlr/render.h>
+#include <wlr/render/gles2.h>
+#include <wlr/render/matrix.h>
+#include <wlr/util/log.h>
+#include <xf86drm.h>
+#include <xf86drmMode.h>
 #include "backend/drm/drm.h"
 #include "backend/drm/iface.h"
 #include "backend/drm/util.h"
+#include "util/signal.h"
 
 bool wlr_drm_check_features(struct wlr_drm_backend *drm) {
 	if (drmSetClientCap(drm->fd, DRM_CLIENT_CAP_UNIVERSAL_PLANES, 1)) {
@@ -870,7 +871,8 @@ void wlr_drm_scan_connectors(struct wlr_drm_backend *drm) {
 			wlr_conn->state = WLR_DRM_CONN_NEEDS_MODESET;
 			wlr_log(L_INFO, "Sending modesetting signal for '%s'",
 				wlr_conn->output.name);
-			wl_signal_emit(&drm->backend.events.output_add, &wlr_conn->output);
+			wlr_signal_emit_safe(&drm->backend.events.new_output,
+				&wlr_conn->output);
 		} else if (wlr_conn->state == WLR_DRM_CONN_CONNECTED &&
 				drm_conn->connection != DRM_MODE_CONNECTED) {
 			wlr_log(L_INFO, "'%s' disconnected", wlr_conn->output.name);
@@ -978,8 +980,6 @@ void wlr_drm_connector_cleanup(struct wlr_drm_connector *conn) {
 		return;
 	}
 
-	struct wlr_drm_backend *drm = (struct wlr_drm_backend *)conn->output.backend;
-
 	switch (conn->state) {
 	case WLR_DRM_CONN_CONNECTED:
 	case WLR_DRM_CONN_CLEANUP:;
@@ -1013,8 +1013,8 @@ void wlr_drm_connector_cleanup(struct wlr_drm_connector *conn) {
 		/* Fallthrough */
 	case WLR_DRM_CONN_NEEDS_MODESET:
 		wlr_log(L_INFO, "Emitting destruction signal for '%s'",
-				conn->output.name);
-		wl_signal_emit(&drm->backend.events.output_remove, &conn->output);
+			conn->output.name);
+		wlr_signal_emit_safe(&conn->output.events.destroy, &conn->output);
 		break;
 	case WLR_DRM_CONN_DISCONNECTED:
 		break;
diff --git a/backend/drm/legacy.c b/backend/drm/legacy.c
index eec8c642..88a01b89 100644
--- a/backend/drm/legacy.c
+++ b/backend/drm/legacy.c
@@ -1,7 +1,7 @@
 #include <gbm.h>
+#include <wlr/util/log.h>
 #include <xf86drm.h>
 #include <xf86drmMode.h>
-#include <wlr/util/log.h>
 #include "backend/drm/drm.h"
 #include "backend/drm/iface.h"
 #include "backend/drm/util.h"
diff --git a/backend/drm/properties.c b/backend/drm/properties.c
index 153e845e..3d35beb5 100644
--- a/backend/drm/properties.c
+++ b/backend/drm/properties.c
@@ -2,9 +2,9 @@
 #include <stddef.h>
 #include <stdint.h>
 #include <stdlib.h>
+#include <wlr/util/log.h>
 #include <xf86drm.h>
 #include <xf86drmMode.h>
-#include <wlr/util/log.h>
 #include "backend/drm/properties.h"
 
 /*
diff --git a/backend/drm/renderer.c b/backend/drm/renderer.c
index 80d3bd9a..f3e570f7 100644
--- a/backend/drm/renderer.c
+++ b/backend/drm/renderer.c
@@ -1,18 +1,16 @@
+#include <EGL/egl.h>
+#include <EGL/eglext.h>
+#include <gbm.h>
+#include <GLES2/gl2.h>
 #include <stdbool.h>
 #include <stdlib.h>
 #include <unistd.h>
-
-#include <gbm.h>
-#include <GLES2/gl2.h>
-#include <EGL/egl.h>
-#include <EGL/eglext.h>
 #include <wayland-util.h>
-
-#include <wlr/util/log.h>
+#include <wlr/render.h>
 #include <wlr/render/egl.h>
-#include <wlr/render/matrix.h>
 #include <wlr/render/gles2.h>
-#include <wlr/render.h>
+#include <wlr/render/matrix.h>
+#include <wlr/util/log.h>
 #include "backend/drm/drm.h"
 #include "glapi.h"
 
diff --git a/backend/drm/util.c b/backend/drm/util.c
index 37d99aa8..41ba47d1 100644
--- a/backend/drm/util.c
+++ b/backend/drm/util.c
@@ -1,10 +1,10 @@
-#include <stdio.h>
-#include <string.h>
-#include <drm.h>
 #include <drm_mode.h>
+#include <drm.h>
 #include <gbm.h>
-#include "backend/drm/util.h"
+#include <stdio.h>
+#include <string.h>
 #include <wlr/util/log.h>
+#include "backend/drm/util.h"
 
 int32_t calculate_refresh_rate(drmModeModeInfo *mode) {
 	int32_t refresh = (mode->clock * 1000000LL / mode->htotal +
diff --git a/backend/headless/backend.c b/backend/headless/backend.c
index 0bf5ec28..663bc13b 100644
--- a/backend/headless/backend.c
+++ b/backend/headless/backend.c
@@ -1,9 +1,10 @@
+#include "util/signal.h"
 #include <stdlib.h>
+#include <wlr/interfaces/wlr_input_device.h>
+#include <wlr/interfaces/wlr_output.h>
 #include <wlr/render/egl.h>
 #include <wlr/render/gles2.h>
 #include <wlr/util/log.h>
-#include <wlr/interfaces/wlr_output.h>
-#include <wlr/interfaces/wlr_input_device.h>
 #include "backend/headless.h"
 #include "glapi.h"
 
@@ -16,14 +17,14 @@ static bool backend_start(struct wlr_backend *wlr_backend) {
 	wl_list_for_each(output, &backend->outputs, link) {
 		wl_event_source_timer_update(output->frame_timer, output->frame_delay);
 		wlr_output_update_enabled(&output->wlr_output, true);
-		wl_signal_emit(&backend->backend.events.output_add,
+		wlr_signal_emit_safe(&backend->backend.events.new_output,
 			&output->wlr_output);
 	}
 
 	struct wlr_headless_input_device *input_device;
 	wl_list_for_each(input_device, &backend->input_devices,
 			wlr_input_device.link) {
-		wl_signal_emit(&backend->backend.events.input_add,
+		wlr_signal_emit_safe(&backend->backend.events.new_input,
 			&input_device->wlr_input_device);
 	}
 
@@ -51,7 +52,7 @@ static void backend_destroy(struct wlr_backend *wlr_backend) {
 		wlr_input_device_destroy(&input_device->wlr_input_device);
 	}
 
-	wl_signal_emit(&wlr_backend->events.destroy, backend);
+	wlr_signal_emit_safe(&wlr_backend->events.destroy, backend);
 
 	wlr_egl_finish(&backend->egl);
 	free(backend);
diff --git a/backend/headless/input_device.c b/backend/headless/input_device.c
index 5c62e87f..ea335aff 100644
--- a/backend/headless/input_device.c
+++ b/backend/headless/input_device.c
@@ -1,17 +1,17 @@
 #include <stdlib.h>
 #include <wlr/interfaces/wlr_input_device.h>
-#include <wlr/interfaces/wlr_pointer.h>
 #include <wlr/interfaces/wlr_keyboard.h>
-#include <wlr/interfaces/wlr_touch.h>
-#include <wlr/interfaces/wlr_tablet_tool.h>
+#include <wlr/interfaces/wlr_pointer.h>
 #include <wlr/interfaces/wlr_tablet_pad.h>
+#include <wlr/interfaces/wlr_tablet_tool.h>
+#include <wlr/interfaces/wlr_touch.h>
 #include <wlr/util/log.h>
 #include "backend/headless.h"
+#include "util/signal.h"
 
 static void input_device_destroy(struct wlr_input_device *wlr_dev) {
 	struct wlr_headless_input_device *device =
 		(struct wlr_headless_input_device *)wlr_dev;
-	wl_signal_emit(&device->backend->backend.events.input_remove, wlr_dev);
 	free(device);
 }
 
@@ -88,7 +88,7 @@ struct wlr_input_device *wlr_headless_add_input_device(
 	wl_list_insert(&backend->input_devices, &wlr_device->link);
 
 	if (backend->started) {
-		wl_signal_emit(&backend->backend.events.input_add, wlr_device);
+		wlr_signal_emit_safe(&backend->backend.events.new_input, wlr_device);
 	}
 
 	return wlr_device;
diff --git a/backend/headless/output.c b/backend/headless/output.c
index 507595a5..ba4a094e 100644
--- a/backend/headless/output.c
+++ b/backend/headless/output.c
@@ -1,10 +1,11 @@
-#include <stdlib.h>
 #include <EGL/egl.h>
 #include <EGL/eglext.h>
 #include <GLES2/gl2.h>
+#include <stdlib.h>
 #include <wlr/interfaces/wlr_output.h>
 #include <wlr/util/log.h>
 #include "backend/headless.h"
+#include "util/signal.h"
 
 static EGLSurface egl_create_surface(struct wlr_egl *egl, unsigned int width,
 		unsigned int height) {
@@ -136,7 +137,7 @@ struct wlr_output *wlr_headless_add_output(struct wlr_backend *wlr_backend,
 	if (backend->started) {
 		wl_event_source_timer_update(output->frame_timer, output->frame_delay);
 		wlr_output_update_enabled(wlr_output, true);
-		wl_signal_emit(&backend->backend.events.output_add, wlr_output);
+		wlr_signal_emit_safe(&backend->backend.events.new_output, wlr_output);
 	}
 
 	return wlr_output;
diff --git a/backend/libinput/backend.c b/backend/libinput/backend.c
index 86477947..71fe0d93 100644
--- a/backend/libinput/backend.c
+++ b/backend/libinput/backend.c
@@ -1,10 +1,11 @@
-#include <stdlib.h>
 #include <assert.h>
 #include <libinput.h>
-#include <wlr/backend/session.h>
+#include <stdlib.h>
 #include <wlr/backend/interface.h>
+#include <wlr/backend/session.h>
 #include <wlr/util/log.h>
 #include "backend/libinput.h"
+#include "util/signal.h"
 
 static int wlr_libinput_open_restricted(const char *path,
 		int flags, void *_backend) {
@@ -106,13 +107,12 @@ static void wlr_libinput_backend_destroy(struct wlr_backend *wlr_backend) {
 		struct wl_list *wlr_devices = backend->wlr_device_lists.items[i];
 		struct wlr_input_device *wlr_dev, *next;
 		wl_list_for_each_safe(wlr_dev, next, wlr_devices, link) {
-			wl_signal_emit(&backend->backend.events.input_remove, wlr_dev);
 			wlr_input_device_destroy(wlr_dev);
 		}
 		free(wlr_devices);
 	}
 
-	wl_signal_emit(&wlr_backend->events.destroy, wlr_backend);
+	wlr_signal_emit_safe(&wlr_backend->events.destroy, wlr_backend);
 
 	wl_list_remove(&backend->display_destroy.link);
 	wl_list_remove(&backend->session_signal.link);
diff --git a/backend/libinput/events.c b/backend/libinput/events.c
index 758a9f25..603eed07 100644
--- a/backend/libinput/events.c
+++ b/backend/libinput/events.c
@@ -1,11 +1,12 @@
-#include <stdlib.h>
 #include <assert.h>
 #include <libinput.h>
+#include <stdlib.h>
+#include <wayland-util.h>
 #include <wlr/backend/session.h>
 #include <wlr/interfaces/wlr_input_device.h>
 #include <wlr/util/log.h>
-#include <wayland-util.h>
 #include "backend/libinput.h"
+#include "util/signal.h"
 
 struct wlr_input_device *get_appropriate_device(
 		enum wlr_input_device_type desired_type,
@@ -88,7 +89,7 @@ static void handle_device_added(struct wlr_libinput_backend *backend,
 			free(wlr_dev);
 			goto fail;
 		}
-		wl_signal_emit(&backend->backend.events.input_add, wlr_dev);
+		wlr_signal_emit_safe(&backend->backend.events.new_input, wlr_dev);
 	}
 	if (libinput_device_has_capability(libinput_dev, LIBINPUT_DEVICE_CAP_POINTER)) {
 		struct wlr_input_device *wlr_dev = allocate_device(backend,
@@ -101,7 +102,7 @@ static void handle_device_added(struct wlr_libinput_backend *backend,
 			free(wlr_dev);
 			goto fail;
 		}
-		wl_signal_emit(&backend->backend.events.input_add, wlr_dev);
+		wlr_signal_emit_safe(&backend->backend.events.new_input, wlr_dev);
 	}
 	if (libinput_device_has_capability(libinput_dev, LIBINPUT_DEVICE_CAP_TOUCH)) {
 		struct wlr_input_device *wlr_dev = allocate_device(backend,
@@ -114,7 +115,7 @@ static void handle_device_added(struct wlr_libinput_backend *backend,
 			free(wlr_dev);
 			goto fail;
 		}
-		wl_signal_emit(&backend->backend.events.input_add, wlr_dev);
+		wlr_signal_emit_safe(&backend->backend.events.new_input, wlr_dev);
 	}
 	if (libinput_device_has_capability(libinput_dev, LIBINPUT_DEVICE_CAP_TABLET_TOOL)) {
 		struct wlr_input_device *wlr_dev = allocate_device(backend,
@@ -127,7 +128,7 @@ static void handle_device_added(struct wlr_libinput_backend *backend,
 			free(wlr_dev);
 			goto fail;
 		}
-		wl_signal_emit(&backend->backend.events.input_add, wlr_dev);
+		wlr_signal_emit_safe(&backend->backend.events.new_input, wlr_dev);
 	}
 	if (libinput_device_has_capability(libinput_dev, LIBINPUT_DEVICE_CAP_TABLET_PAD)) {
 		struct wlr_input_device *wlr_dev = allocate_device(backend,
@@ -140,7 +141,7 @@ static void handle_device_added(struct wlr_libinput_backend *backend,
 			free(wlr_dev);
 			goto fail;
 		}
-		wl_signal_emit(&backend->backend.events.input_add, wlr_dev);
+		wlr_signal_emit_safe(&backend->backend.events.new_input, wlr_dev);
 	}
 	if (libinput_device_has_capability(libinput_dev, LIBINPUT_DEVICE_CAP_GESTURE)) {
 		// TODO
@@ -178,7 +179,6 @@ static void handle_device_removed(struct wlr_libinput_backend *backend,
 	}
 	struct wlr_input_device *dev, *tmp_dev;
 	wl_list_for_each_safe(dev, tmp_dev, wlr_devices, link) {
-		wl_signal_emit(&backend->backend.events.input_remove, dev);
 		wlr_input_device_destroy(dev);
 	}
 	for (size_t i = 0; i < backend->wlr_device_lists.length; i++) {
diff --git a/backend/libinput/keyboard.c b/backend/libinput/keyboard.c
index 065d8ead..b44bc892 100644
--- a/backend/libinput/keyboard.c
+++ b/backend/libinput/keyboard.c
@@ -1,9 +1,9 @@
-#include <stdlib.h>
 #include <assert.h>
 #include <libinput.h>
+#include <stdlib.h>
 #include <wlr/backend/session.h>
-#include <wlr/types/wlr_input_device.h>
 #include <wlr/interfaces/wlr_keyboard.h>
+#include <wlr/types/wlr_input_device.h>
 #include <wlr/util/log.h>
 #include "backend/libinput.h"
 
@@ -57,7 +57,7 @@ void handle_keyboard_key(struct libinput_event *event,
 	wlr_event.time_msec =
 		usec_to_msec(libinput_event_keyboard_get_time_usec(kbevent));
 	wlr_event.keycode = libinput_event_keyboard_get_key(kbevent);
-	enum libinput_key_state state = 
+	enum libinput_key_state state =
 		libinput_event_keyboard_get_key_state(kbevent);
 	switch (state) {
 	case LIBINPUT_KEY_STATE_RELEASED:
diff --git a/backend/libinput/pointer.c b/backend/libinput/pointer.c
index 13402ac2..8a31d312 100644
--- a/backend/libinput/pointer.c
+++ b/backend/libinput/pointer.c
@@ -1,11 +1,12 @@
-#include <stdlib.h>
 #include <assert.h>
 #include <libinput.h>
+#include <stdlib.h>
 #include <wlr/backend/session.h>
-#include <wlr/types/wlr_input_device.h>
 #include <wlr/interfaces/wlr_pointer.h>
+#include <wlr/types/wlr_input_device.h>
 #include <wlr/util/log.h>
 #include "backend/libinput.h"
+#include "util/signal.h"
 
 struct wlr_pointer *wlr_libinput_pointer_create(
 		struct libinput_device *libinput_dev) {
@@ -35,7 +36,7 @@ void handle_pointer_motion(struct libinput_event *event,
 		usec_to_msec(libinput_event_pointer_get_time_usec(pevent));
 	wlr_event.delta_x = libinput_event_pointer_get_dx(pevent);
 	wlr_event.delta_y = libinput_event_pointer_get_dy(pevent);
-	wl_signal_emit(&wlr_dev->pointer->events.motion, &wlr_event);
+	wlr_signal_emit_safe(&wlr_dev->pointer->events.motion, &wlr_event);
 }
 
 void handle_pointer_motion_abs(struct libinput_event *event,
@@ -55,7 +56,7 @@ void handle_pointer_motion_abs(struct libinput_event *event,
 	wlr_event.x_mm = libinput_event_pointer_get_absolute_x(pevent);
 	wlr_event.y_mm = libinput_event_pointer_get_absolute_y(pevent);
 	libinput_device_get_size(libinput_dev, &wlr_event.width_mm, &wlr_event.height_mm);
-	wl_signal_emit(&wlr_dev->pointer->events.motion_absolute, &wlr_event);
+	wlr_signal_emit_safe(&wlr_dev->pointer->events.motion_absolute, &wlr_event);
 }
 
 void handle_pointer_button(struct libinput_event *event,
@@ -81,7 +82,7 @@ void handle_pointer_button(struct libinput_event *event,
 		wlr_event.state = WLR_BUTTON_RELEASED;
 		break;
 	}
-	wl_signal_emit(&wlr_dev->pointer->events.button, &wlr_event);
+	wlr_signal_emit_safe(&wlr_dev->pointer->events.button, &wlr_event);
 }
 
 void handle_pointer_axis(struct libinput_event *event,
@@ -128,7 +129,7 @@ void handle_pointer_axis(struct libinput_event *event,
 			}
 			wlr_event.delta = libinput_event_pointer_get_axis_value(
 					pevent, axies[i]);
-			wl_signal_emit(&wlr_dev->pointer->events.axis, &wlr_event);
+			wlr_signal_emit_safe(&wlr_dev->pointer->events.axis, &wlr_event);
 		}
 	}
 }
diff --git a/backend/libinput/tablet_pad.c b/backend/libinput/tablet_pad.c
index 7dac3b7c..70e4c677 100644
--- a/backend/libinput/tablet_pad.c
+++ b/backend/libinput/tablet_pad.c
@@ -1,11 +1,12 @@
-#include <stdlib.h>
 #include <assert.h>
 #include <libinput.h>
+#include <stdlib.h>
 #include <wlr/backend/session.h>
-#include <wlr/types/wlr_input_device.h>
 #include <wlr/interfaces/wlr_tablet_pad.h>
+#include <wlr/types/wlr_input_device.h>
 #include <wlr/util/log.h>
 #include "backend/libinput.h"
+#include "util/signal.h"
 
 struct wlr_tablet_pad *wlr_libinput_tablet_pad_create(
 		struct libinput_device *libinput_dev) {
@@ -41,7 +42,7 @@ void handle_tablet_pad_button(struct libinput_event *event,
 		wlr_event.state = WLR_BUTTON_RELEASED;
 		break;
 	}
-	wl_signal_emit(&wlr_dev->tablet_pad->events.button, &wlr_event);
+	wlr_signal_emit_safe(&wlr_dev->tablet_pad->events.button, &wlr_event);
 }
 
 void handle_tablet_pad_ring(struct libinput_event *event,
@@ -67,7 +68,7 @@ void handle_tablet_pad_ring(struct libinput_event *event,
 		wlr_event.source = WLR_TABLET_PAD_RING_SOURCE_FINGER;
 		break;
 	}
-	wl_signal_emit(&wlr_dev->tablet_pad->events.ring, &wlr_event);
+	wlr_signal_emit_safe(&wlr_dev->tablet_pad->events.ring, &wlr_event);
 }
 
 void handle_tablet_pad_strip(struct libinput_event *event,
@@ -93,5 +94,5 @@ void handle_tablet_pad_strip(struct libinput_event *event,
 		wlr_event.source = WLR_TABLET_PAD_STRIP_SOURCE_FINGER;
 		break;
 	}
-	wl_signal_emit(&wlr_dev->tablet_pad->events.strip, &wlr_event);
+	wlr_signal_emit_safe(&wlr_dev->tablet_pad->events.strip, &wlr_event);
 }
diff --git a/backend/libinput/tablet_tool.c b/backend/libinput/tablet_tool.c
index 3d5fafc3..4e60367f 100644
--- a/backend/libinput/tablet_tool.c
+++ b/backend/libinput/tablet_tool.c
@@ -1,11 +1,12 @@
-#include <stdlib.h>
 #include <assert.h>
 #include <libinput.h>
+#include <stdlib.h>
 #include <wlr/backend/session.h>
-#include <wlr/types/wlr_input_device.h>
 #include <wlr/interfaces/wlr_tablet_tool.h>
+#include <wlr/types/wlr_input_device.h>
 #include <wlr/util/log.h>
 #include "backend/libinput.h"
+#include "util/signal.h"
 
 struct wlr_tablet_tool *wlr_libinput_tablet_tool_create(
 		struct libinput_device *libinput_dev) {
@@ -72,7 +73,7 @@ void handle_tablet_tool_axis(struct libinput_event *event,
 	}
 	wlr_log(L_DEBUG, "Tablet tool axis event %d @ %f,%f",
 			wlr_event.updated_axes, wlr_event.x_mm, wlr_event.y_mm);
-	wl_signal_emit(&wlr_dev->tablet_tool->events.axis, &wlr_event);
+	wlr_signal_emit_safe(&wlr_dev->tablet_tool->events.axis, &wlr_event);
 }
 
 void handle_tablet_tool_proximity(struct libinput_event *event,
@@ -98,7 +99,7 @@ void handle_tablet_tool_proximity(struct libinput_event *event,
 		handle_tablet_tool_axis(event, libinput_dev);
 		break;
 	}
-	wl_signal_emit(&wlr_dev->tablet_tool->events.proximity, &wlr_event);
+	wlr_signal_emit_safe(&wlr_dev->tablet_tool->events.proximity, &wlr_event);
 }
 
 void handle_tablet_tool_tip(struct libinput_event *event,
@@ -124,7 +125,7 @@ void handle_tablet_tool_tip(struct libinput_event *event,
 		wlr_event.state = WLR_TABLET_TOOL_TIP_DOWN;
 		break;
 	}
-	wl_signal_emit(&wlr_dev->tablet_tool->events.tip, &wlr_event);
+	wlr_signal_emit_safe(&wlr_dev->tablet_tool->events.tip, &wlr_event);
 }
 
 void handle_tablet_tool_button(struct libinput_event *event,
@@ -151,5 +152,5 @@ void handle_tablet_tool_button(struct libinput_event *event,
 		wlr_event.state = WLR_BUTTON_PRESSED;
 		break;
 	}
-	wl_signal_emit(&wlr_dev->tablet_tool->events.button, &wlr_event);
+	wlr_signal_emit_safe(&wlr_dev->tablet_tool->events.button, &wlr_event);
 }
diff --git a/backend/libinput/touch.c b/backend/libinput/touch.c
index 0ba6ec86..2b87f9cd 100644
--- a/backend/libinput/touch.c
+++ b/backend/libinput/touch.c
@@ -1,11 +1,12 @@
-#include <stdlib.h>
 #include <assert.h>
 #include <libinput.h>
+#include <stdlib.h>
 #include <wlr/backend/session.h>
-#include <wlr/types/wlr_input_device.h>
 #include <wlr/interfaces/wlr_touch.h>
+#include <wlr/types/wlr_input_device.h>
 #include <wlr/util/log.h>
 #include "backend/libinput.h"
+#include "util/signal.h"
 
 struct wlr_touch *wlr_libinput_touch_create(
 		struct libinput_device *libinput_dev) {
@@ -37,7 +38,7 @@ void handle_touch_down(struct libinput_event *event,
 	wlr_event.x_mm = libinput_event_touch_get_x(tevent);
 	wlr_event.y_mm = libinput_event_touch_get_y(tevent);
 	libinput_device_get_size(libinput_dev, &wlr_event.width_mm, &wlr_event.height_mm);
-	wl_signal_emit(&wlr_dev->touch->events.down, &wlr_event);
+	wlr_signal_emit_safe(&wlr_dev->touch->events.down, &wlr_event);
 }
 
 void handle_touch_up(struct libinput_event *event,
@@ -55,7 +56,7 @@ void handle_touch_up(struct libinput_event *event,
 	wlr_event.time_msec =
 		usec_to_msec(libinput_event_touch_get_time_usec(tevent));
 	wlr_event.touch_id = libinput_event_touch_get_slot(tevent);
-	wl_signal_emit(&wlr_dev->touch->events.up, &wlr_event);
+	wlr_signal_emit_safe(&wlr_dev->touch->events.up, &wlr_event);
 }
 
 void handle_touch_motion(struct libinput_event *event,
@@ -76,7 +77,7 @@ void handle_touch_motion(struct libinput_event *event,
 	wlr_event.x_mm = libinput_event_touch_get_x(tevent);
 	wlr_event.y_mm = libinput_event_touch_get_y(tevent);
 	libinput_device_get_size(libinput_dev, &wlr_event.width_mm, &wlr_event.height_mm);
-	wl_signal_emit(&wlr_dev->touch->events.motion, &wlr_event);
+	wlr_signal_emit_safe(&wlr_dev->touch->events.motion, &wlr_event);
 }
 
 void handle_touch_cancel(struct libinput_event *event,
@@ -94,5 +95,5 @@ void handle_touch_cancel(struct libinput_event *event,
 	wlr_event.time_msec =
 		usec_to_msec(libinput_event_touch_get_time_usec(tevent));
 	wlr_event.touch_id = libinput_event_touch_get_slot(tevent);
-	wl_signal_emit(&wlr_dev->touch->events.cancel, &wlr_event);
+	wlr_signal_emit_safe(&wlr_dev->touch->events.cancel, &wlr_event);
 }
diff --git a/backend/meson.build b/backend/meson.build
index beb3841c..bac43063 100644
--- a/backend/meson.build
+++ b/backend/meson.build
@@ -1,7 +1,5 @@
 backend_files = files(
 	'backend.c',
-	'session/direct-ipc.c',
-	'session/session.c',
 	'drm/atomic.c',
 	'drm/backend.c',
 	'drm/drm.c',
@@ -10,8 +8,8 @@ backend_files = files(
 	'drm/renderer.c',
 	'drm/util.c',
 	'headless/backend.c',
-	'headless/output.c',
 	'headless/input_device.c',
+	'headless/output.c',
 	'libinput/backend.c',
 	'libinput/events.c',
 	'libinput/keyboard.c',
@@ -20,6 +18,8 @@ backend_files = files(
 	'libinput/tablet_tool.c',
 	'libinput/touch.c',
 	'multi/backend.c',
+	'session/direct-ipc.c',
+	'session/session.c',
 	'wayland/backend.c',
 	'wayland/output.c',
 	'wayland/registry.c',
diff --git a/backend/multi/backend.c b/backend/multi/backend.c
index 78f5c63b..5cb3fbc5 100644
--- a/backend/multi/backend.c
+++ b/backend/multi/backend.c
@@ -4,17 +4,16 @@
 #include <wlr/backend/interface.h>
 #include <wlr/backend/session.h>
 #include <wlr/util/log.h>
-#include "backend/multi.h"
 #include "backend/drm/drm.h"
+#include "backend/multi.h"
+#include "util/signal.h"
 
 struct subbackend_state {
 	struct wlr_backend *backend;
 	struct wlr_backend *container;
-	struct wl_listener input_add;
-	struct wl_listener input_remove;
-	struct wl_listener output_add;
-	struct wl_listener output_remove;
-	struct wl_listener backend_destroy;
+	struct wl_listener new_input;
+	struct wl_listener new_output;
+	struct wl_listener destroy;
 	struct wl_list link;
 };
 
@@ -31,11 +30,9 @@ static bool multi_backend_start(struct wlr_backend *wlr_backend) {
 }
 
 static void subbackend_state_destroy(struct subbackend_state *sub) {
-	wl_list_remove(&sub->input_add.link);
-	wl_list_remove(&sub->input_remove.link);
-	wl_list_remove(&sub->output_add.link);
-	wl_list_remove(&sub->output_remove.link);
-	wl_list_remove(&sub->backend_destroy.link);
+	wl_list_remove(&sub->new_input.link);
+	wl_list_remove(&sub->new_output.link);
+	wl_list_remove(&sub->destroy.link);
 	wl_list_remove(&sub->link);
 	free(sub);
 }
@@ -51,7 +48,7 @@ static void multi_backend_destroy(struct wlr_backend *wlr_backend) {
 	}
 
 	// Destroy this backend only after removing all sub-backends
-	wl_signal_emit(&wlr_backend->events.destroy, backend);
+	wlr_signal_emit_safe(&wlr_backend->events.destroy, backend);
 	free(backend);
 }
 
@@ -117,34 +114,21 @@ bool wlr_backend_is_multi(struct wlr_backend *b) {
 	return b->impl == &backend_impl;
 }
 
-static void input_add_reemit(struct wl_listener *listener, void *data) {
-	struct subbackend_state *state = wl_container_of(listener,
-			state, input_add);
-	wl_signal_emit(&state->container->events.input_add, data);
-}
-
-static void input_remove_reemit(struct wl_listener *listener, void *data) {
+static void new_input_reemit(struct wl_listener *listener, void *data) {
 	struct subbackend_state *state = wl_container_of(listener,
-			state, input_remove);
-	wl_signal_emit(&state->container->events.input_remove, data);
+			state, new_input);
+	wlr_signal_emit_safe(&state->container->events.new_input, data);
 }
 
-static void output_add_reemit(struct wl_listener *listener, void *data) {
+static void new_output_reemit(struct wl_listener *listener, void *data) {
 	struct subbackend_state *state = wl_container_of(listener,
-			state, output_add);
-	wl_signal_emit(&state->container->events.output_add, data);
-}
-
-static void output_remove_reemit(struct wl_listener *listener, void *data) {
-	struct subbackend_state *state = wl_container_of(listener,
-			state, output_remove);
-	wl_signal_emit(&state->container->events.output_remove, data);
+			state, new_output);
+	wlr_signal_emit_safe(&state->container->events.new_output, data);
 }
 
 static void handle_subbackend_destroy(struct wl_listener *listener,
 		void *data) {
-	struct subbackend_state *state = wl_container_of(listener,
-			state, backend_destroy);
+	struct subbackend_state *state = wl_container_of(listener, state, destroy);
 	subbackend_state_destroy(state);
 }
 
@@ -179,22 +163,16 @@ void wlr_multi_backend_add(struct wlr_backend *_multi,
 	sub->backend = backend;
 	sub->container = &multi->backend;
 
-	wl_signal_add(&backend->events.destroy, &sub->backend_destroy);
-	sub->backend_destroy.notify = handle_subbackend_destroy;
-
-	wl_signal_add(&backend->events.input_add, &sub->input_add);
-	sub->input_add.notify = input_add_reemit;
-
-	wl_signal_add(&backend->events.input_remove, &sub->input_remove);
-	sub->input_remove.notify = input_remove_reemit;
+	wl_signal_add(&backend->events.destroy, &sub->destroy);
+	sub->destroy.notify = handle_subbackend_destroy;
 
-	wl_signal_add(&backend->events.output_add, &sub->output_add);
-	sub->output_add.notify = output_add_reemit;
+	wl_signal_add(&backend->events.new_input, &sub->new_input);
+	sub->new_input.notify = new_input_reemit;
 
-	wl_signal_add(&backend->events.output_remove, &sub->output_remove);
-	sub->output_remove.notify = output_remove_reemit;
+	wl_signal_add(&backend->events.new_output, &sub->new_output);
+	sub->new_output.notify = new_output_reemit;
 
-	wl_signal_emit(&multi->events.backend_add, backend);
+	wlr_signal_emit_safe(&multi->events.backend_add, backend);
 }
 
 void wlr_multi_backend_remove(struct wlr_backend *_multi,
@@ -206,7 +184,7 @@ void wlr_multi_backend_remove(struct wlr_backend *_multi,
 		multi_backend_get_subbackend(multi, backend);
 
 	if (sub) {
-		wl_signal_emit(&multi->events.backend_remove, backend);
+		wlr_signal_emit_safe(&multi->events.backend_remove, backend);
 		subbackend_state_destroy(sub);
 	}
 }
diff --git a/backend/session/direct-freebsd.c b/backend/session/direct-freebsd.c
index c0621416..6e23bf1b 100644
--- a/backend/session/direct-freebsd.c
+++ b/backend/session/direct-freebsd.c
@@ -1,21 +1,22 @@
+#include <dev/evdev/input.h>
 #include <errno.h>
-#include <stdlib.h>
-#include <stdio.h>
-#include <stdbool.h>
-#include <unistd.h>
+#include <fcntl.h>
 #include <signal.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/consio.h>
 #include <sys/ioctl.h>
+#include <sys/kbio.h>
 #include <sys/stat.h>
-#include <termios.h>
-#include <fcntl.h>
 #include <sys/types.h>
-#include <dev/evdev/input.h>
-#include <sys/kbio.h>
-#include <sys/consio.h>
+#include <termios.h>
+#include <unistd.h>
 #include <wayland-server.h>
 #include <wlr/backend/session/interface.h>
 #include <wlr/util/log.h>
 #include "backend/session/direct-ipc.h"
+#include "util/signal.h"
 
 const struct session_impl session_direct;
 
@@ -95,12 +96,12 @@ static int vt_handler(int signo, void *data) {
 
 	if (session->base.active) {
 		session->base.active = false;
-		wl_signal_emit(&session->base.session_signal, session);
+		wlr_signal_emit_safe(&session->base.session_signal, session);
 		ioctl(session->tty_fd, VT_RELDISP, 1);
 	} else {
 		ioctl(session->tty_fd, VT_RELDISP, VT_ACKACQ);
 		session->base.active = true;
-		wl_signal_emit(&session->base.session_signal, session);
+		wlr_signal_emit_safe(&session->base.session_signal, session);
 	}
 
 	return 1;
diff --git a/backend/session/direct-ipc.c b/backend/session/direct-ipc.c
index e7a169fa..6c69b70a 100644
--- a/backend/session/direct-ipc.c
+++ b/backend/session/direct-ipc.c
@@ -4,22 +4,22 @@
 #define INPUT_MAJOR 0
 #endif
 #include <errno.h>
+#include <fcntl.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include <fcntl.h>
-#include <unistd.h>
 #include <sys/socket.h>
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <sys/wait.h>
+#include <unistd.h>
+#include <wlr/config.h>
+#include <wlr/util/log.h>
+#include <xf86drm.h>
 #ifdef __linux__
 #include <sys/sysmacros.h>
 #include <linux/major.h>
 #endif
-#include <xf86drm.h>
-#include <wlr/config.h>
-#include <wlr/util/log.h>
 #include "backend/session/direct-ipc.h"
 
 enum { DRM_MAJOR = 226 };
diff --git a/backend/session/direct.c b/backend/session/direct.c
index 9d6cd36d..13a26d99 100644
--- a/backend/session/direct.c
+++ b/backend/session/direct.c
@@ -1,21 +1,22 @@
 #define _POSIX_C_SOURCE 200809L
 #include <errno.h>
-#include <stdlib.h>
-#include <stdio.h>
-#include <stdbool.h>
-#include <unistd.h>
+#include <linux/input.h>
+#include <linux/kd.h>
+#include <linux/major.h>
+#include <linux/vt.h>
 #include <signal.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
 #include <sys/ioctl.h>
 #include <sys/stat.h>
 #include <sys/sysmacros.h>
-#include <linux/kd.h>
-#include <linux/major.h>
-#include <linux/input.h>
-#include <linux/vt.h>
+#include <unistd.h>
 #include <wayland-server.h>
 #include <wlr/backend/session/interface.h>
 #include <wlr/util/log.h>
 #include "backend/session/direct-ipc.h"
+#include "util/signal.h"
 
 enum { DRM_MAJOR = 226 };
 
@@ -107,7 +108,7 @@ static int vt_handler(int signo, void *data) {
 
 	if (session->base.active) {
 		session->base.active = false;
-		wl_signal_emit(&session->base.session_signal, session);
+		wlr_signal_emit_safe(&session->base.session_signal, session);
 
 		struct wlr_device *dev;
 		wl_list_for_each(dev, &session->base.devices, link) {
@@ -130,7 +131,7 @@ static int vt_handler(int signo, void *data) {
 		}
 
 		session->base.active = true;
-		wl_signal_emit(&session->base.session_signal, session);
+		wlr_signal_emit_safe(&session->base.session_signal, session);
 	}
 
 	return 1;
diff --git a/backend/session/logind.c b/backend/session/logind.c
index 1ece051f..f0ac1e93 100644
--- a/backend/session/logind.c
+++ b/backend/session/logind.c
@@ -1,25 +1,26 @@
 #define _POSIX_C_SOURCE 200809L
 #include <assert.h>
-#include <stdio.h>
+#include <errno.h>
+#include <fcntl.h>
 #include <stdbool.h>
+#include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include <errno.h>
-#include <unistd.h>
-#include <sys/sysmacros.h>
 #include <sys/stat.h>
-#include <fcntl.h>
+#include <sys/sysmacros.h>
+#include <unistd.h>
 #include <wayland-server.h>
-#include <wlr/config.h>
 #include <wlr/backend/session/interface.h>
+#include <wlr/config.h>
 #include <wlr/util/log.h>
+#include "util/signal.h"
 
 #ifdef WLR_HAS_SYSTEMD
 	#include <systemd/sd-bus.h>
 	#include <systemd/sd-login.h>
 #elif defined(WLR_HAS_ELOGIND)
 	#include <elogind/sd-bus.h>
-	#include <elogind/sd-login.h> 
+	#include <elogind/sd-login.h>
 #endif
 
 enum { DRM_MAJOR = 226 };
@@ -250,7 +251,7 @@ static int pause_device(sd_bus_message *msg, void *userdata, sd_bus_error *ret_e
 
 	if (major == DRM_MAJOR) {
 		session->base.active = false;
-		wl_signal_emit(&session->base.session_signal, session);
+		wlr_signal_emit_safe(&session->base.session_signal, session);
 	}
 
 	if (strcmp(type, "pause") == 0) {
@@ -286,7 +287,7 @@ static int resume_device(sd_bus_message *msg, void *userdata, sd_bus_error *ret_
 
 		if (!session->base.active) {
 			session->base.active = true;
-			wl_signal_emit(&session->base.session_signal, session);
+			wlr_signal_emit_safe(&session->base.session_signal, session);
 		}
 	}
 
diff --git a/backend/session/session.c b/backend/session/session.c
index 2bbbd4ef..2d5d9776 100644
--- a/backend/session/session.c
+++ b/backend/session/session.c
@@ -1,18 +1,19 @@
 #define _POSIX_C_SOURCE 200809L
 #include <assert.h>
+#include <libudev.h>
 #include <stddef.h>
 #include <stdlib.h>
 #include <string.h>
 #include <sys/stat.h>
 #include <sys/types.h>
-#include <libudev.h>
 #include <wayland-server.h>
-#include <xf86drm.h>
-#include <xf86drmMode.h>
-#include <wlr/config.h>
 #include <wlr/backend/session.h>
 #include <wlr/backend/session/interface.h>
+#include <wlr/config.h>
 #include <wlr/util/log.h>
+#include <xf86drm.h>
+#include <xf86drmMode.h>
+#include "util/signal.h"
 
 extern const struct session_impl session_logind;
 extern const struct session_impl session_direct;
@@ -49,7 +50,7 @@ static int udev_event(int fd, uint32_t mask, void *data) {
 
 	wl_list_for_each(dev, &session->devices, link) {
 		if (dev->dev == devnum) {
-			wl_signal_emit(&dev->signal, session);
+			wlr_signal_emit_safe(&dev->signal, session);
 			break;
 		}
 	}
diff --git a/backend/wayland/backend.c b/backend/wayland/backend.c
index 458c9dd0..abb25df5 100644
--- a/backend/wayland/backend.c
+++ b/backend/wayland/backend.c
@@ -1,17 +1,18 @@
-#include <stdlib.h>
-#include <stdint.h>
 #include <assert.h>
-#include <limits.h>
 #include <EGL/egl.h>
 #include <EGL/eglext.h>
+#include <limits.h>
+#include <stdint.h>
+#include <stdlib.h>
 #include <wayland-server.h>
-#include <wlr/render/egl.h>
-#include <wlr/render/gles2.h>
 #include <wlr/backend/interface.h>
-#include <wlr/interfaces/wlr_output.h>
 #include <wlr/interfaces/wlr_input_device.h>
+#include <wlr/interfaces/wlr_output.h>
+#include <wlr/render/egl.h>
+#include <wlr/render/gles2.h>
 #include <wlr/util/log.h>
 #include "backend/wayland.h"
+#include "util/signal.h"
 #include "xdg-shell-unstable-v6-client-protocol.h"
 
 static int dispatch_events(int fd, uint32_t mask, void *data) {
@@ -80,7 +81,7 @@ static void wlr_wl_backend_destroy(struct wlr_backend *wlr_backend) {
 		wlr_input_device_destroy(input_device);
 	}
 
-	wl_signal_emit(&wlr_backend->events.destroy, wlr_backend);
+	wlr_signal_emit_safe(&wlr_backend->events.destroy, wlr_backend);
 
 	wl_list_remove(&backend->local_display_destroy.link);
 
diff --git a/backend/wayland/output.c b/backend/wayland/output.c
index 0bbf6d42..fc40dea0 100644
--- a/backend/wayland/output.c
+++ b/backend/wayland/output.c
@@ -1,16 +1,17 @@
-#include <stdio.h>
 #include <assert.h>
+#include <GLES2/gl2.h>
 #include <stdint.h>
+#include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include <unistd.h>
-#include <sys/types.h>
 #include <sys/mman.h>
+#include <sys/types.h>
+#include <unistd.h>
 #include <wayland-client.h>
-#include <GLES2/gl2.h>
 #include <wlr/interfaces/wlr_output.h>
 #include <wlr/util/log.h>
 #include "backend/wayland.h"
+#include "util/signal.h"
 #include "xdg-shell-unstable-v6-client-protocol.h"
 
 int os_create_anonymous_file(off_t size);
@@ -338,7 +339,7 @@ struct wlr_output *wlr_wl_output_create(struct wlr_backend *_backend) {
 
 	wl_list_insert(&backend->outputs, &output->link);
 	wlr_output_update_enabled(wlr_output, true);
-	wl_signal_emit(&backend->backend.events.output_add, wlr_output);
+	wlr_signal_emit_safe(&backend->backend.events.new_output, wlr_output);
 	return wlr_output;
 
 error:
diff --git a/backend/wayland/registry.c b/backend/wayland/registry.c
index 0dec0ec5..4aa39f09 100644
--- a/backend/wayland/registry.c
+++ b/backend/wayland/registry.c
@@ -6,7 +6,6 @@
 #include "backend/wayland.h"
 #include "xdg-shell-unstable-v6-client-protocol.h"
 
-
 static void xdg_shell_handle_ping(void *data, struct zxdg_shell_v6 *shell,
 		uint32_t serial) {
 	zxdg_shell_v6_pong(shell, serial);
diff --git a/backend/wayland/wl_seat.c b/backend/wayland/wl_seat.c
index 37489678..b1f7cff6 100644
--- a/backend/wayland/wl_seat.c
+++ b/backend/wayland/wl_seat.c
@@ -1,16 +1,17 @@
 #define _XOPEN_SOURCE 500
 #include <assert.h>
-#include <stdlib.h>
 #include <stdint.h>
+#include <stdlib.h>
 #include <string.h>
 #include <wayland-client.h>
-#include <wlr/interfaces/wlr_output.h>
 #include <wlr/interfaces/wlr_input_device.h>
-#include <wlr/interfaces/wlr_pointer.h>
 #include <wlr/interfaces/wlr_keyboard.h>
+#include <wlr/interfaces/wlr_output.h>
+#include <wlr/interfaces/wlr_pointer.h>
 #include <wlr/interfaces/wlr_touch.h>
 #include <wlr/util/log.h>
 #include "backend/wayland.h"
+#include "util/signal.h"
 
 static void pointer_handle_enter(void *data, struct wl_pointer *wl_pointer,
 		uint32_t serial, struct wl_surface *surface, wl_fixed_t surface_x,
@@ -78,7 +79,7 @@ static void pointer_handle_motion(void *data, struct wl_pointer *wl_pointer,
 	wlr_event.height_mm = layout_box.height;
 	wlr_event.x_mm = transformed.x + wlr_output->lx - layout_box.x;
 	wlr_event.y_mm = transformed.y + wlr_output->ly - layout_box.y;
-	wl_signal_emit(&dev->pointer->events.motion_absolute, &wlr_event);
+	wlr_signal_emit_safe(&dev->pointer->events.motion_absolute, &wlr_event);
 }
 
 static void pointer_handle_button(void *data, struct wl_pointer *wl_pointer,
@@ -91,7 +92,7 @@ static void pointer_handle_button(void *data, struct wl_pointer *wl_pointer,
 	wlr_event.button = button;
 	wlr_event.state = state;
 	wlr_event.time_msec = time;
-	wl_signal_emit(&dev->pointer->events.button, &wlr_event);
+	wlr_signal_emit_safe(&dev->pointer->events.button, &wlr_event);
 }
 
 static void pointer_handle_axis(void *data, struct wl_pointer *wl_pointer,
@@ -106,7 +107,7 @@ static void pointer_handle_axis(void *data, struct wl_pointer *wl_pointer,
 	wlr_event.orientation = axis;
 	wlr_event.time_msec = time;
 	wlr_event.source = wlr_wl_pointer->axis_source;
-	wl_signal_emit(&dev->pointer->events.axis, &wlr_event);
+	wlr_signal_emit_safe(&dev->pointer->events.axis, &wlr_event);
 }
 
 static void pointer_handle_frame(void *data, struct wl_pointer *wl_pointer) {
@@ -192,9 +193,8 @@ static struct wl_keyboard_listener keyboard_listener = {
 	.repeat_info = keyboard_handle_repeat_info
 };
 
-static void input_device_destroy(struct wlr_input_device *_dev) {
-	struct wlr_wl_input_device *dev = (struct wlr_wl_input_device *)_dev;
-	wl_signal_emit(&dev->backend->backend.events.input_remove, &dev->wlr_input_device);
+static void input_device_destroy(struct wlr_input_device *wlr_dev) {
+	struct wlr_wl_input_device *dev = (struct wlr_wl_input_device *)wlr_dev;
 	if (dev->resource) {
 		wl_proxy_destroy(dev->resource);
 	}
@@ -256,7 +256,7 @@ static void seat_handle_capabilities(void *data, struct wl_seat *wl_seat,
 		wlr_device->pointer = &wlr_wl_pointer->wlr_pointer;
 		wlr_pointer_init(wlr_device->pointer, NULL);
 		wlr_wl_device->resource = wl_pointer;
-		wl_signal_emit(&backend->backend.events.input_add, wlr_device);
+		wlr_signal_emit_safe(&backend->backend.events.new_input, wlr_device);
 		backend->pointer = wl_pointer;
 	}
 	if ((caps & WL_SEAT_CAPABILITY_KEYBOARD)) {
@@ -280,7 +280,7 @@ static void seat_handle_capabilities(void *data, struct wl_seat *wl_seat,
 		struct wl_keyboard *wl_keyboard = wl_seat_get_keyboard(wl_seat);
 		wl_keyboard_add_listener(wl_keyboard, &keyboard_listener, wlr_device);
 		wlr_wl_device->resource = wl_keyboard;
-		wl_signal_emit(&backend->backend.events.input_add, wlr_device);
+		wlr_signal_emit_safe(&backend->backend.events.new_input, wlr_device);
 	}
 }
 
diff --git a/backend/x11/backend.c b/backend/x11/backend.c
index 411d0ef6..28a4fcac 100644
--- a/backend/x11/backend.c
+++ b/backend/x11/backend.c
@@ -1,28 +1,29 @@
 #define _POSIX_C_SOURCE 200112L
+#include <EGL/egl.h>
 #include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <time.h>
-#include <EGL/egl.h>
 #include <wayland-server.h>
-#include <xcb/xcb.h>
-#include <xcb/glx.h>
-#include <X11/Xlib-xcb.h>
-#ifdef __linux__
-#include <linux/input-event-codes.h>
-#elif __FreeBSD__
-#include <dev/evdev/input-event-codes.h>
-#endif
 #include <wlr/backend/interface.h>
 #include <wlr/backend/x11.h>
-#include <wlr/render/egl.h>
-#include <wlr/render/gles2.h>
-#include <wlr/interfaces/wlr_output.h>
 #include <wlr/interfaces/wlr_input_device.h>
 #include <wlr/interfaces/wlr_keyboard.h>
+#include <wlr/interfaces/wlr_output.h>
 #include <wlr/interfaces/wlr_pointer.h>
+#include <wlr/render/egl.h>
+#include <wlr/render/gles2.h>
 #include <wlr/util/log.h>
+#include <X11/Xlib-xcb.h>
+#include <xcb/glx.h>
+#include <xcb/xcb.h>
+#ifdef __linux__
+#include <linux/input-event-codes.h>
+#elif __FreeBSD__
+#include <dev/evdev/input-event-codes.h>
+#endif
 #include "backend/x11.h"
+#include "util/signal.h"
 
 static struct wlr_backend_impl backend_impl;
 static struct wlr_output_impl output_impl;
@@ -77,7 +78,7 @@ static bool handle_x11_event(struct wlr_x11_backend *x11, xcb_generic_event_t *e
 				.orientation = WLR_AXIS_ORIENTATION_VERTICAL,
 				.delta = delta,
 			};
-			wl_signal_emit(&x11->pointer.events.axis, &axis);
+			wlr_signal_emit_safe(&x11->pointer.events.axis, &axis);
 			x11->time = ev->time;
 			break;
 		}
@@ -96,7 +97,7 @@ static bool handle_x11_event(struct wlr_x11_backend *x11, xcb_generic_event_t *e
 					WLR_BUTTON_PRESSED : WLR_BUTTON_RELEASED,
 			};
 
-			wl_signal_emit(&x11->pointer.events.button, &button);
+			wlr_signal_emit_safe(&x11->pointer.events.button, &button);
 		}
 		x11->time = ev->time;
 		break;
@@ -112,7 +113,7 @@ static bool handle_x11_event(struct wlr_x11_backend *x11, xcb_generic_event_t *e
 			.height_mm = output->wlr_output.height,
 		};
 
-		wl_signal_emit(&x11->pointer.events.motion_absolute, &abs);
+		wlr_signal_emit_safe(&x11->pointer.events.motion_absolute, &abs);
 		x11->time = ev->time;
 		break;
 	}
@@ -140,7 +141,7 @@ static bool handle_x11_event(struct wlr_x11_backend *x11, xcb_generic_event_t *e
 			.height_mm = output->wlr_output.height,
 		};
 
-		wl_signal_emit(&x11->pointer.events.motion_absolute, &abs);
+		wlr_signal_emit_safe(&x11->pointer.events.motion_absolute, &abs);
 		break;
 	}
 	case XCB_GLX_DELETE_QUERIES_ARB: {
@@ -229,9 +230,9 @@ static bool wlr_x11_backend_start(struct wlr_backend *backend) {
 	xcb_flush(x11->xcb_conn);
 	wlr_output_update_enabled(&output->wlr_output, true);
 
-	wl_signal_emit(&x11->backend.events.output_add, output);
-	wl_signal_emit(&x11->backend.events.input_add, &x11->keyboard_dev);
-	wl_signal_emit(&x11->backend.events.input_add, &x11->pointer_dev);
+	wlr_signal_emit_safe(&x11->backend.events.new_output, output);
+	wlr_signal_emit_safe(&x11->backend.events.new_input, &x11->keyboard_dev);
+	wlr_signal_emit_safe(&x11->backend.events.new_input, &x11->pointer_dev);
 
 	wl_event_source_timer_update(x11->frame_timer, 16);
 
@@ -248,8 +249,8 @@ static void wlr_x11_backend_destroy(struct wlr_backend *backend) {
 	struct wlr_x11_output *output = &x11->output;
 	wlr_output_destroy(&output->wlr_output);
 
-	wl_signal_emit(&backend->events.input_remove, &x11->pointer_dev);
-	wl_signal_emit(&backend->events.input_remove, &x11->keyboard_dev);
+	wlr_signal_emit_safe(&x11->pointer_dev.events.destroy, &x11->pointer_dev);
+	wlr_signal_emit_safe(&x11->keyboard_dev.events.destroy, &x11->keyboard_dev);
 	// TODO probably need to use wlr_keyboard_destroy, but the devices need to
 	// be malloced for that to work
 	if (x11->keyboard_dev.keyboard->keymap) {
@@ -259,7 +260,7 @@ static void wlr_x11_backend_destroy(struct wlr_backend *backend) {
 		xkb_state_unref(x11->keyboard_dev.keyboard->xkb_state);
 	}
 
-	wl_signal_emit(&backend->events.destroy, backend);
+	wlr_signal_emit_safe(&backend->events.destroy, backend);
 
 	wl_list_remove(&x11->display_destroy.link);