Mac: Fix deadlock in the accelerated drawing code.

chrome/browser/renderer_host/render_widget_host_view_mac.mm

 // Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <QuartzCore/QuartzCore.h>
 
 #include "chrome/browser/renderer_host/render_widget_host_view_mac.h"
 
 #include "chrome/browser/chrome_thread.h"
 #include "app/surface/io_surface_support_mac.h"
@@ skipping 142 matching lines @@
 
   RenderWidgetHostViewMac* renderWidgetHostView_;  // weak
   gfx::PluginWindowHandle pluginHandle_;  // weak
 
   // True if the backing IO surface was updated since we last painted.
   BOOL surfaceWasSwapped_;
 
   // Cocoa methods can only be called on the main thread, so have a copy of the
   // view's size, since it's required on the displaylink thread.
   NSSize cachedSize_;
+
+  // -globalFrameDidChange: can be called recursively, this counts how often it
+  // holds the CGL lock.
+  int globalFrameDidChangeCGLLockCount_;
 }
 
 - (id)initWithRenderWidgetHostViewMac:(RenderWidgetHostViewMac*)r
                          pluginHandle:(gfx::PluginWindowHandle)pluginHandle;
 - (void)drawView;
 
 // This _must_ be atomic, since it's accessed from several threads.
 @property BOOL surfaceWasSwapped;
 
 // This _must_ be atomic, since it's accessed from several threads.
@@ skipping 104 matching lines @@
 - (void)rightMouseDown:(NSEvent*)event {
   // The NSResponder documentation: "Note: The NSView implementation of this
   // method does not pass the message up the responder chain, it handles it
   // directly."
   // That's bad, we want the next responder (RWHVMac) to handle this event to
   // dispatch it to the renderer.
   [[self nextResponder] rightMouseDown:event];
 }
 
 - (void)globalFrameDidChange:(NSNotification*)notification {
+  globalFrameDidChangeCGLLockCount_++;

[pink (ping after 24hrs), 2010/09/29 21:08:54]

can you add a comment here as to where globalFrameDidChange: is called
recurively? it's not obvious.

   CGLLockContext(cglContext_);
   [glContext_ update];
 
   // You would think that -update updates the viewport. You would be wrong.
   CGLSetCurrentContext(cglContext_);
   NSSize size = [self frame].size;
   glViewport(0, 0, size.width, size.height);
 
   CGLUnlockContext(cglContext_);
+  globalFrameDidChangeCGLLockCount_--;
 
-  // Make sure the view is synchronized with the correct display.
-  CVDisplayLinkSetCurrentCGDisplayFromOpenGLContext(
+  if (globalFrameDidChangeCGLLockCount_ == 0) {
+    // Make sure the view is synchronized with the correct display.
+    CVDisplayLinkSetCurrentCGDisplayFromOpenGLContext(
        displayLink_, cglContext_, cglPixelFormat_);
+  }
 }
 
 - (void)renewGState {
   // Synchronize with window server to avoid flashes or corrupt drawing.
   [[self window] disableScreenUpdatesUntilFlush];
   [self globalFrameDidChange:nil];
   [super renewGState];
 }
 
 - (void)lockFocus {
@@ skipping 12 matching lines @@
     CVDisplayLinkSetOutputCallback(
         displayLink_, &DrawOneAcceleratedPluginCallback, self);
     CVDisplayLinkSetCurrentCGDisplayFromOpenGLContext(
         displayLink_, cglContext_, cglPixelFormat_);
     CVDisplayLinkStart(displayLink_);
   }
   [glContext_ makeCurrentContext];
 }
 
 - (void)viewWillMoveToWindow:(NSWindow*)newWindow {
-  if (CommandLine::ForCurrentProcess()->HasSwitch(
-      switches::kDisableHolePunching)) {
-    return;
-  }
-
-  if ([[self window] respondsToSelector:@selector(underlaySurfaceRemoved)]) {
-    [static_cast<id>([self window]) underlaySurfaceRemoved];
-  }
-
-  if ([newWindow respondsToSelector:@selector(underlaySurfaceAdded)]) {
-    [static_cast<id>(newWindow) underlaySurfaceAdded];
-  }
-
   // Stop the display link thread while the view is not visible.
   if (newWindow) {
     if (displayLink_ && !CVDisplayLinkIsRunning(displayLink_))
       CVDisplayLinkStart(displayLink_);
   } else {
     if (displayLink_ && CVDisplayLinkIsRunning(displayLink_))
       CVDisplayLinkStop(displayLink_);
   }
+
+  // If hole pushing is enabled, inform the window hosing this accelerated view

[pink (ping after 24hrs), 2010/09/29 21:08:11]

hole pushing or hole punching? hosing or hosting?

[Nico, 2010/09/29 21:14:02]

freud strikes again

+  // that it needs to be opaque.
+  if (!CommandLine::ForCurrentProcess()->HasSwitch(
+      switches::kDisableHolePunching)) {
+    if ([[self window] respondsToSelector:@selector(underlaySurfaceRemoved)]) {
+      [static_cast<id>([self window]) underlaySurfaceRemoved];
+    }
+
+    if ([newWindow respondsToSelector:@selector(underlaySurfaceAdded)]) {
+      [static_cast<id>(newWindow) underlaySurfaceAdded];
+    }
+  }
 }
 
 - (void)setFrame:(NSRect)frameRect {
   [self setCachedSize:frameRect.size];
   [super setFrame:frameRect];
 }
 
 - (void)setFrameSize:(NSSize)newSize {
   [self setCachedSize:newSize];
   [super setFrameSize:newSize];
@@ skipping 2076 matching lines @@
   if (!string) return NO;
 
   // If the user is currently using an IME, confirm the IME input,
   // and then insert the text from the service, the same as TextEdit and Safari.
   [self confirmComposition];
   [self insertText:string];
   return YES;
 }
 
 @end