cocoa: OpenGL setView and update must be used on main thread (thanks,…

… Tim!). If called from background threads, use Grand Central Dispatch to use the main thread instead. On the main thread, just call them directly. Fixes Bugzilla #4932.
libsdl-org · Apr 7, 2020 · 309d613 · 309d613
1 parent 486f0b6
commit 309d613
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Showing 2 changed files with 29 additions and 11 deletions.
diff --git a/src/video/cocoa/SDL_cocoaopengl.h b/src/video/cocoa/SDL_cocoaopengl.h
@@ -49,6 +49,8 @@ struct SDL_GLDriverData
 - (void)scheduleUpdate;
 - (void)updateIfNeeded;
 - (void)setWindow:(SDL_Window *)window;
+- (SDL_Window*)window;
+- (void)explicitUpdate;
 
 @end
 

diff --git a/src/video/cocoa/SDL_cocoaopengl.m b/src/video/cocoa/SDL_cocoaopengl.m
@@ -63,14 +63,10 @@ - (void)scheduleUpdate
 /* This should only be called on the thread on which a user is using the context. */
 - (void)updateIfNeeded
 {
-    int value = SDL_AtomicSet(&self->dirty, 0);
+    const int value = SDL_AtomicSet(&self->dirty, 0);
     if (value > 0) {
         /* We call the real underlying update here, since -[SDLOpenGLContext update] just calls us. */
-        if ([NSThread isMainThread]) {
-            [super update];
-        } else {
-            [super performSelectorOnMainThread:@selector(update) withObject:nil waitUntilDone:NO];
-        }
+        [self explicitUpdate];
     }
 }
 
@@ -119,23 +115,41 @@ - (void)setWindow:(SDL_Window *)newWindow
         }
 
         if ([self view] != contentview) {
-            [self setView:contentview];
+            if ([NSThread isMainThread]) {
+                [self setView:contentview];
+            } else {
+                dispatch_sync(dispatch_get_main_queue(), ^{ [self setView:contentview]; });
+            }
             if (self == [NSOpenGLContext currentContext]) {
-                [self update];
+                [self explicitUpdate];
             } else {
                 [self scheduleUpdate];
             }
         }
     } else {
         [self clearDrawable];
         if (self == [NSOpenGLContext currentContext]) {
-            [self update];
+            [self explicitUpdate];
         } else {
             [self scheduleUpdate];
         }
     }
 }
 
+- (SDL_Window*)window
+{
+    return self->window;
+}
+
+- (void)explicitUpdate
+{
+    if ([NSThread isMainThread]) {
+        [super update];
+    } else {
+        dispatch_sync(dispatch_get_main_queue(), ^{ [super update]; });
+    }
+}
+
 @end
 
 
@@ -352,8 +366,10 @@ - (void)setWindow:(SDL_Window *)newWindow
 {
     if (context) {
         SDLOpenGLContext *nscontext = (SDLOpenGLContext *)context;
-        [nscontext setWindow:window];
-        [nscontext updateIfNeeded];
+        if ([nscontext window] != window) {
+            [nscontext setWindow:window];
+            [nscontext updateIfNeeded];
+        }
         [nscontext makeCurrentContext];
     } else {
         [NSOpenGLContext clearCurrentContext];