#580 <loading message..>

CHANGELOG.md

@@ -5,6 +5,8 @@ All notable changes to this project will be documented in this file.
 This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
+### Changed
+- Fixed a race condition upon receiving window destroy notifications from macOS because their API is garbage and reports duplicate notifications for the same window [#580](https://github.com/koekeishiya/yabai/issues/580)
 
 ## [3.2.0] - 2020-06-14
 ### Added

src/application.c

@@ -10,10 +10,9 @@ static OBSERVER_CALLBACK(application_notification_handler)
         uint32_t *window_id_ptr = *(uint32_t **) context;
         if (!window_id_ptr) return;
 
-        uint32_t window_id = *window_id_ptr;
-        while (!__sync_bool_compare_and_swap((uint32_t **) context, window_id_ptr, NULL));
+        if (!__sync_bool_compare_and_swap((uint32_t **) context, window_id_ptr, NULL)) return;
 
-        event_loop_post(&g_event_loop, WINDOW_DESTROYED, (void *)(uintptr_t) window_id, 0, NULL);
+        event_loop_post(&g_event_loop, WINDOW_DESTROYED, (void *)(uintptr_t) *window_id_ptr, 0, NULL);
     } else if (CFEqual(notification, kAXFocusedWindowChangedNotification)) {
         uint32_t window_id = ax_window_id(element);
         if (window_id) event_loop_post(&g_event_loop, WINDOW_FOCUSED, (void *)(intptr_t) window_id, 0, NULL);
@@ -41,7 +40,7 @@ static OBSERVER_CALLBACK(application_notification_handler)
 static void
 application_observe_notification(struct application *application, int notification)
 {
-    AXError result = _AXObserverAddNotification(application->observer_ref, application->ref, ax_application_notification[notification], application);
+    AXError result = AXObserverAddNotification(application->observer_ref, application->ref, ax_application_notification[notification], application);
     if (result == kAXErrorSuccess || result == kAXErrorNotificationAlreadyRegistered) {
         application->notification |= 1 << notification;
     } else {
@@ -53,7 +52,7 @@ application_observe_notification(struct application *application, int notificati
 static void
 application_unobserve_notification(struct application *application, int notification)
 {
-    _AXObserverRemoveNotification(application->observer_ref, application->ref, ax_application_notification[notification]);
+    AXObserverRemoveNotification(application->observer_ref, application->ref, ax_application_notification[notification]);
     application->notification &= ~(1 << notification);
 }
 

src/manifest.m

@@ -12,7 +12,6 @@
 #include <stdbool.h>
 #include <assert.h>
 #include <fcntl.h>
-#include <dlfcn.h>
 #include <regex.h>
 #include <execinfo.h>
 #include <signal.h>

src/misc/helpers.h

@@ -3,14 +3,6 @@
 
 extern AXError _AXUIElementGetWindow(AXUIElementRef ref, uint32_t *wid);
 
-#define AXOBSERVER_ADD_NOTIFICATION(name) AXError name(AXObserverRef observer, AXUIElementRef application, CFStringRef notification, void *context)
-typedef AXOBSERVER_ADD_NOTIFICATION(axobserver_add_notification);
-axobserver_add_notification *_AXObserverAddNotification;
-
-#define AXOBSERVER_REMOVE_NOTIFICATION(name) AXError name(AXObserverRef observer, AXUIElementRef application, CFStringRef notification)
-typedef AXOBSERVER_REMOVE_NOTIFICATION(axobserver_remove_notification);
-axobserver_remove_notification *_AXObserverRemoveNotification;
-
 static const char *bool_str[] = { "off", "on" };
 
 static const char *layer_str[] =

src/window.c

@@ -8,7 +8,7 @@ extern int g_connection;
 static void
 window_observe_notification(struct window *window, int notification)
 {
-    AXError result = _AXObserverAddNotification(window->application->observer_ref, window->ref, ax_window_notification[notification], window->id_ptr);
+    AXError result = AXObserverAddNotification(window->application->observer_ref, window->ref, ax_window_notification[notification], window->id_ptr);
     if (result == kAXErrorSuccess || result == kAXErrorNotificationAlreadyRegistered) {
         window->notification |= 1 << notification;
     } else {
@@ -19,7 +19,7 @@ window_observe_notification(struct window *window, int notification)
 static void
 window_unobserve_notification(struct window *window, int notification)
 {
-    _AXObserverRemoveNotification(window->application->observer_ref, window->ref, ax_window_notification[notification]);
+    AXObserverRemoveNotification(window->application->observer_ref, window->ref, ax_window_notification[notification]);
     window->notification &= ~(1 << notification);
 }
 

src/yabai.c

@@ -182,26 +182,6 @@ static void exec_config_file(void)
     }
 }
 
-static inline void load_axobserver_async(void)
-{
-    void *handle = dlopen("/System/Library/Frameworks/ApplicationServices.framework/Frameworks/HIServices.framework/Versions/Current/HIServices", RTLD_LAZY);
-    if (handle) {
-        _AXObserverAddNotification = dlsym(handle, "AXObserverAddNotificationAsync");
-        _AXObserverRemoveNotification = dlsym(handle, "AXObserverRemoveNotificationAsync");
-
-        if (_AXObserverAddNotification && _AXObserverRemoveNotification) {
-            debug("%s: loaded AXObserverAddNotificationAsync and AXObserverRemoveNotificationAsync\n", __FUNCTION__);
-            return;
-        }
-
-        dlclose(handle);
-    }
-
-    _AXObserverAddNotification = &AXObserverAddNotification;
-    _AXObserverRemoveNotification = &AXObserverRemoveNotification;
-    debug("%s: falling back to AXObserverAddNotification and AXObserverRemoveNotification\n", __FUNCTION__);
-}
-
 #pragma clang diagnostic push
 #pragma clang diagnostic ignored "-Wdeprecated-declarations"
 static inline void init_misc_settings(void)
@@ -291,7 +271,6 @@ int main(int argc, char **argv)
         error("yabai: could not access accessibility features! abort..\n");
     }
 
-    load_axobserver_async();
     init_misc_settings();
     acquire_lockfile();