Bitmap transport

chrome/browser/renderer_host/render_widget_helper.h

-
 // Copyright (c) 2006-2008 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.
 
 #ifndef CHROME_BROWSER_RENDEDER_HOST_RENDER_WIDGET_HELPER_H_
 #define CHROME_BROWSER_RENDEDER_HOST_RENDER_WIDGET_HELPER_H_
 
 #include "base/atomic_sequence_num.h"
 #include "base/hash_tables.h"
 #include "base/process.h"
 #include "base/ref_counted.h"
 #include "base/lock.h"
 #include "base/waitable_event.h"
+#include "chrome/common/ipc_maybe.h"
 #include "chrome/common/modal_dialog_event.h"
+#include "chrome/common/transport_dib.h"
 
 namespace IPC {
 class Message;
 }
 
 namespace base {
 class TimeDelta;
 }
 
 class MessageLoop;
@@ skipping 41 matching lines @@
 //   RenderWidget, which triggers a full PaintRect message.)  This can lead to
 //   an observed rendering glitch as the WebContents will just have to fill
 //   white overtop the RenderWidgetHost until the RenderWidgetHost receives a
 //   PaintRect message to refresh its backingstore.
 //
 //   To avoid this 'white flash', the RenderWidgetHost again makes use of the
 //   RenderWidgetHelper's WaitForPaintMsg method.  When the RenderWidgetHost's
 //   GetBackingStore method is called, it will call WaitForPaintMsg if it has
 //   no backingstore.
 //
+// TRANSPORT DIB CREATION
+//
+//   On some platforms (currently the Mac) the renderer cannot create transport
+//   DIBs because of sandbox limitations. Thus, it has to make synchronous IPCs
+//   to the browser for them. Since these requests are synchronous, they cannot
+//   terminate on the UI thread. Thus, in this case, this object performs the
+//   allocation and maintains the set of allocated transport DIBs which the
+//   renderers can refer to.
+//
 class RenderWidgetHelper :
     public base::RefCountedThreadSafe<RenderWidgetHelper> {
  public:
   RenderWidgetHelper(int render_process_id);
   ~RenderWidgetHelper();
 
   // Gets the next available routing id.  This is thread safe.
   int GetNextRoutingID();
 
   // Sets whether popup blocking is enabled or not.
   void set_block_popups(bool block) { block_popups_ = block; }
 
 
   // UI THREAD ONLY -----------------------------------------------------------
 
   // These three functions provide the backend implementation of the
   // corresponding functions in RenderProcessHost. See those declarations
   // for documentation.
   void CancelResourceRequests(int render_widget_id);
   void CrossSiteClosePageACK(int new_render_process_host_id,
                              int new_request_id);
   bool WaitForPaintMsg(int render_widget_id,
                        const base::TimeDelta& max_delay,
                        IPC::Message* msg);
 
+#if defined(OS_MACOSX)
+  // Given the id of a transport DIB, return a mapping to it or NULL on error.
+  TransportDIB* MapTransportDIB(TransportDIB::Id dib_id);
+#endif
+
 
   // IO THREAD ONLY -----------------------------------------------------------
 
   // Called on the IO thread when a PaintRect message is received.
   void DidReceivePaintMsg(const IPC::Message& msg);
 
   MessageLoop* ui_loop() { return ui_loop_; }
 
   void CreateNewWindow(int opener_id,
                        bool user_gesture,
                        base::ProcessHandle render_process,
                        int* route_id,
                        ModalDialogEvent* modal_dialog_event);
   void CreateNewWidget(int opener_id, bool activatable, int* route_id);
 
+#if defined(OS_MACOSX)
+  // Called on the IO thread to handle the allocation of a transport DIB
+  void AllocTransportDIB(size_t size, IPC::Maybe<TransportDIB::Handle>* result);
+
+  // Called on the IO thread to handle the freeing of a transport DIB
+  void FreeTransportDIB(TransportDIB::Id dib_id);
+#endif
+
  private:
   // A class used to proxy a paint message.  PaintMsgProxy objects are created
   // on the IO thread and destroyed on the UI thread.
   class PaintMsgProxy;
   friend class PaintMsgProxy;
 
   // Map from render_widget_id to live PaintMsgProxy instance.
   typedef base::hash_map<int, PaintMsgProxy*> PaintMsgProxyMap;
 
   // Called on the UI thread to discard a paint message.
   void OnDiscardPaintMsg(PaintMsgProxy* proxy);
 
   // Called on the UI thread to dispatch a paint message if necessary.
   void OnDispatchPaintMsg(PaintMsgProxy* proxy);
 
   // Called on the UI thread to send a message to the RenderProcessHost.
   void OnSimulateReceivedMessage(const IPC::Message& message);
 
   // Called on the IO thread to cancel resource requests for the render widget.
   void OnCancelResourceRequests(ResourceDispatcherHost* dispatcher,
                                 int render_widget_id);
 
   // Called on the IO thread to resume a cross-site response.
   void OnCrossSiteClosePageACK(ResourceDispatcherHost* dispatcher,
                                int new_render_process_host_id,
                                int new_request_id);
 
+#if defined(OS_MACOSX)
+  // Called on destruction to release all allocated transport DIBs
+  void ClearAllocatedDIBs();
+
+  // On OSX we keep file descriptors to all the allocated DIBs around until
+  // the renderer frees them.
+  Lock allocated_dibs_lock_;
+  std::map<TransportDIB::Id, int> allocated_dibs_;
+#endif
+
   // A map of live paint messages.  Must hold pending_paints_lock_ to access.
   // The PaintMsgProxy objects are not owned by this map.  (See PaintMsgProxy
   // for details about how the lifetime of instances are managed.)
   PaintMsgProxyMap pending_paints_;
   Lock pending_paints_lock_;
 
   int render_process_id_;
   MessageLoop* ui_loop_;
 
   // Event used to implement WaitForPaintMsg.
   base::WaitableEvent event_;
 
   // The next routing id to use.
   base::AtomicSequenceNumber next_routing_id_;
 
   // Whether popup blocking is enabled or not.
   bool block_popups_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderWidgetHelper);
 };
 
 #endif  // CHROME_BROWSER_RENDEDER_HOST_RENDER_WIDGET_HELPER_H_