Map: Guard concurrent accesses to a std::map by a lock in drawing code.

chrome/browser/renderer_host/accelerated_surface_container_manager_mac.cc

 // 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 "chrome/browser/renderer_host/accelerated_surface_container_manager_mac.h"
 
 #include "base/logging.h"
 #include "chrome/browser/renderer_host/accelerated_surface_container_mac.h"
 #include "webkit/glue/plugins/webplugin.h"
 
 AcceleratedSurfaceContainerManagerMac::AcceleratedSurfaceContainerManagerMac()
     : current_id_(0),
       root_container_(NULL),
       root_container_handle_(gfx::kNullPluginWindow),
       gpu_rendering_active_(false) {
 }
 
 gfx::PluginWindowHandle
 AcceleratedSurfaceContainerManagerMac::AllocateFakePluginWindowHandle(
     bool opaque, bool root) {
+  AutoLock lock(lock_);
+
   AcceleratedSurfaceContainerMac* container =
       new AcceleratedSurfaceContainerMac(this, opaque);
   gfx::PluginWindowHandle res =
       static_cast<gfx::PluginWindowHandle>(++current_id_);
   plugin_window_to_container_map_.insert(std::make_pair(res, container));
   if (root) {
     root_container_ = container;
     root_container_handle_ = res;
   }
   return res;
 }
 
 void AcceleratedSurfaceContainerManagerMac::DestroyFakePluginWindowHandle(
     gfx::PluginWindowHandle id) {
+  AutoLock lock(lock_);
+
   AcceleratedSurfaceContainerMac* container = MapIDToContainer(id);
   if (container) {
     if (container == root_container_) {
       root_container_ = NULL;
       root_container_handle_ = gfx::kNullPluginWindow;
     }
     delete container;
   }
   plugin_window_to_container_map_.erase(id);
 }
 
 bool AcceleratedSurfaceContainerManagerMac::IsRootContainer(
     gfx::PluginWindowHandle id) const {
   return root_container_handle_ != gfx::kNullPluginWindow &&
       root_container_handle_ == id;
 }
 
 void AcceleratedSurfaceContainerManagerMac::SetSizeAndIOSurface(
     gfx::PluginWindowHandle id,
     int32 width,
     int32 height,
     uint64 io_surface_identifier) {
+  AutoLock lock(lock_);
+
   AcceleratedSurfaceContainerMac* container = MapIDToContainer(id);
   if (container) {
     container->SetSizeAndIOSurface(width, height, io_surface_identifier);
   }
 }
 
 void AcceleratedSurfaceContainerManagerMac::SetSizeAndTransportDIB(
     gfx::PluginWindowHandle id,
     int32 width,
     int32 height,
     TransportDIB::Handle transport_dib) {
+  AutoLock lock(lock_);
+
   AcceleratedSurfaceContainerMac* container = MapIDToContainer(id);
   if (container)
     container->SetSizeAndTransportDIB(width, height, transport_dib);
 }
 
 void AcceleratedSurfaceContainerManagerMac::SetPluginContainerGeometry(
     const webkit_glue::WebPluginGeometry& move) {
+  AutoLock lock(lock_);
+
   AcceleratedSurfaceContainerMac* container = MapIDToContainer(move.window);
   if (container)
     container->SetGeometry(move);
 }
 
 void AcceleratedSurfaceContainerManagerMac::Draw(CGLContextObj context,
                                                  gfx::PluginWindowHandle id) {
+  AutoLock lock(lock_);
+
   glColorMask(true, true, true, true);
   glClearColor(0, 0, 0, 0);
   glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
   glDisable(GL_DEPTH_TEST);
   glDisable(GL_BLEND);
 
   glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
 
   AcceleratedSurfaceContainerMac* container = MapIDToContainer(id);
   CHECK(container);
   container->Draw(context);
 
   // Unbind any texture from the texture target to ensure that the
   // next time through we will have to re-bind the texture and thereby
   // pick up modifications from the other process.
   GLenum target = GL_TEXTURE_RECTANGLE_ARB;
   glBindTexture(target, 0);
 
   glFlush();
 }
 
 void AcceleratedSurfaceContainerManagerMac::ForceTextureReload() {
+  AutoLock lock(lock_);
+
   for (PluginWindowToContainerMap::const_iterator i =
           plugin_window_to_container_map_.begin();
        i != plugin_window_to_container_map_.end(); ++i) {
     AcceleratedSurfaceContainerMac* container = i->second;
     container->ForceTextureReload();
   }
 }
 
 void AcceleratedSurfaceContainerManagerMac::SetSurfaceWasPaintedTo(
     gfx::PluginWindowHandle id) {
+  AutoLock lock(lock_);
+
   AcceleratedSurfaceContainerMac* container = MapIDToContainer(id);
   if (container)
     container->set_was_painted_to();
 }
 
 bool AcceleratedSurfaceContainerManagerMac::SurfaceShouldBeVisible(
     gfx::PluginWindowHandle id) const {
+  AutoLock lock(lock_);
+
   if (IsRootContainer(id) && !gpu_rendering_active_)
     return false;
 
   AcceleratedSurfaceContainerMac* container = MapIDToContainer(id);
   return container && container->should_be_visible();
 }
 
 AcceleratedSurfaceContainerMac*
     AcceleratedSurfaceContainerManagerMac::MapIDToContainer(
         gfx::PluginWindowHandle id) const {
   PluginWindowToContainerMap::const_iterator i =
       plugin_window_to_container_map_.find(id);
   if (i != plugin_window_to_container_map_.end())
     return i->second;
 
   LOG(ERROR) << "Request for plugin container for unknown window id " << id;
 
   return NULL;
 }