Expose locks for CopyFromCompositingSurface/CopyFromBackingStore API

content/browser/renderer_host/render_widget_host_view_android.cc

 // Copyright (c) 2012 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 "content/browser/renderer_host/render_widget_host_view_android.h"
 
 #include <android/bitmap.h>
 
 #include "base/basictypes.h"
 #include "base/bind.h"
@@ skipping 129 matching lines @@
       overscroll_effect_(OverscrollGlow::Create(overscroll_effect_enabled_)),
       flush_input_requested_(false),
       accelerated_surface_route_id_(0),
       using_synchronous_compositor_(SynchronousCompositorImpl::FromID(
                                         widget_host->GetProcess()->GetID(),
                                         widget_host->GetRoutingID()) != NULL),
       frame_evictor_(new DelegatedFrameEvictor(this)),
       using_delegated_renderer_(CommandLine::ForCurrentProcess()->HasSwitch(
                                     switches::kEnableDelegatedRenderer) &&
                                 !CommandLine::ForCurrentProcess()->HasSwitch(
-                                    switches::kDisableDelegatedRenderer)) {
+                                    switches::kDisableDelegatedRenderer)),
+      locks_on_frame_count_(0) {
   if (!using_delegated_renderer_) {
     texture_layer_ = cc::TextureLayer::Create(NULL);
     layer_ = texture_layer_;
   }
 
   host_->SetView(this);
   SetContentViewCore(content_view_core);
   ImageTransportFactoryAndroid::AddObserver(this);
 }
 
@@ skipping 117 matching lines @@
 
 bool RenderWidgetHostViewAndroid::HasValidFrame() const {
   if (!content_view_core_)
     return false;
   if (!layer_)
     return false;
 
   if (texture_size_in_layer_.IsEmpty())
     return false;
 
+  if (!frame_evictor_->HasFrame())
+    return false;
+
   if (using_delegated_renderer_) {
     if (!delegated_renderer_layer_.get())
       return false;
   } else {
     if (texture_id_in_layer_ == 0)
       return false;
   }
 
   return true;
 }
@@ skipping 70 matching lines @@
   WasHidden();
 }
 
 bool RenderWidgetHostViewAndroid::IsShowing() {
   // ContentViewCoreImpl represents the native side of the Java
   // ContentViewCore.  It being NULL means that it is not attached
   // to the View system yet, so we treat this RWHVA as hidden.
   return is_showing_ && content_view_core_;
 }
 
-void RenderWidgetHostViewAndroid::LockResources() {
+void RenderWidgetHostViewAndroid::LockSurfaceForCopy() {
   DCHECK(HasValidFrame());
   DCHECK(host_);
-  DCHECK(!host_->is_hidden());
+  DCHECK(frame_evictor_->HasFrame());
   frame_evictor_->LockFrame();
+  locks_on_frame_count_++;
 }
 
-void RenderWidgetHostViewAndroid::UnlockResources() {
+void RenderWidgetHostViewAndroid::UnlockSurfaceForCopy() {
+  if (!frame_evictor_->HasFrame() || locks_on_frame_count_ == 0)
+    return;
+
   DCHECK(HasValidFrame());
   frame_evictor_->UnlockFrame();
+  locks_on_frame_count_--;
+}
+
+void RenderWidgetHostViewAndroid::ReleaseLocksOnSurface() {
+  if (!frame_evictor_->HasFrame()) {
+    DCHECK_EQ(locks_on_frame_count_, 0u);
+    return;
+  }
+  while (locks_on_frame_count_ > 0) {
+    UnlockSurfaceForCopy();
+  }
 }
 
 gfx::Rect RenderWidgetHostViewAndroid::GetViewBounds() const {
   if (!content_view_core_)
     return gfx::Rect(default_size_);
 
   gfx::Size size = content_view_core_->GetViewportSizeDip();
   gfx::Size offset = content_view_core_->GetViewportSizeOffsetDip();
   size.Enlarge(-offset.width(), -offset.height());
 
@@ skipping 403 matching lines @@
       layer_->layer_tree_host()->QueueSwapPromise(swap_promise.Pass());
     }
   }
 
   if (frame->delegated_frame_data) {
     DCHECK(using_delegated_renderer_);
 
     DCHECK(frame->delegated_frame_data);
     DCHECK(!frame->delegated_frame_data->render_pass_list.empty());
 
+    if (locks_on_frame_count_ > 0) {
+      DCHECK(HasValidFrame());
+      base::Closure ack_callback =
+          base::Bind(&RenderWidgetHostViewAndroid::SendDelegatedFrameAck,
+                     weak_ptr_factory_.GetWeakPtr(),
+                     output_surface_id);
+      if (host_->is_hidden())
+        ack_callback.Run();
+      else
+        ack_callbacks_.push(ack_callback);
+      return;

[piman, 2014/03/05 20:14:36]

So, if my understanding is correct, while there is a lock, we discard incoming
frames from the renderer? Should we keep the last one around to  swap in when
the lock count drops to 0?

[powei, 2014/03/06 07:41:40]

Yes
Done.  PTAL.

+    }
     cc::RenderPass* root_pass =
         frame->delegated_frame_data->render_pass_list.back();
     texture_size_in_layer_ = root_pass->output_rect.size();
     ComputeContentsSize(frame->metadata);
 
     SwapDelegatedFrame(output_surface_id, frame->delegated_frame_data.Pass());
     frame_evictor_->SwappedFrame(!host_->is_hidden());
     return;
   }
 
@@ skipping 432 matching lines @@
 }
 
 void RenderWidgetHostViewAndroid::SetContentViewCore(
     ContentViewCoreImpl* content_view_core) {
   RunAckCallbacks();
 
   RemoveLayers();
   if (content_view_core_ && !using_synchronous_compositor_)
     content_view_core_->GetWindowAndroid()->RemoveObserver(this);
 
+  if (content_view_core != content_view_core_)
+    ReleaseLocksOnSurface();
+
   content_view_core_ = content_view_core;
 
   if (GetBrowserAccessibilityManager()) {
     base::android::ScopedJavaLocalRef<jobject> obj;
     if (content_view_core_)
       obj = content_view_core_->GetJavaObject();
     GetBrowserAccessibilityManager()->ToBrowserAccessibilityManagerAndroid()->
         SetContentViewCore(obj);
   }
 
@@ skipping 13 matching lines @@
   RunAckCallbacks();
 }
 
 void RenderWidgetHostViewAndroid::OnDetachCompositor() {
   DCHECK(content_view_core_);
   DCHECK(!using_synchronous_compositor_);
   RunAckCallbacks();
 }
 
 void RenderWidgetHostViewAndroid::OnLostResources() {
+  ReleaseLocksOnSurface();
   if (texture_layer_.get())
     texture_layer_->SetIsDrawable(false);
   if (delegated_renderer_layer_.get())
     DestroyDelegatedContent();
   texture_id_in_layer_ = 0;
   RunAckCallbacks();
 }
 
 // static
 void RenderWidgetHostViewAndroid::PrepareTextureCopyOutputResult(
@@ skipping 104 matching lines @@
 // RenderWidgetHostView, public:
 
 // static
 RenderWidgetHostView*
 RenderWidgetHostView::CreateViewForWidget(RenderWidgetHost* widget) {
   RenderWidgetHostImpl* rwhi = RenderWidgetHostImpl::From(widget);
   return new RenderWidgetHostViewAndroid(rwhi, NULL);
 }
 
 } // namespace content