Drop frontbuffers with ui-use-gpu-process, synchronized with browser, decoupled from backbuffer dro…

content/browser/renderer_host/render_widget_host_view_aura.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_aura.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
 #include "base/logging.h"
-#include "base/memory/weak_ptr.h"
 #include "base/message_loop.h"
 #include "base/string_number_conversions.h"
 #include "content/browser/renderer_host/backing_store_aura.h"
 #include "content/browser/renderer_host/dip_util.h"
 #include "content/browser/renderer_host/render_view_host_delegate.h"
 #include "content/browser/renderer_host/render_widget_host_impl.h"
 #include "content/browser/renderer_host/web_input_event_aura.h"
 #include "content/common/gpu/client/gl_helper.h"
 #include "content/common/gpu/gpu_messages.h"
 #include "content/port/browser/render_widget_host_view_port.h"
@@ skipping 103 matching lines @@
   results->horizontalDPI = default_dpi;
 }
 
 bool ShouldSendPinchGesture() {
   static bool pinch_allowed =
       CommandLine::ForCurrentProcess()->HasSwitch(switches::kEnableViewport) ||
       CommandLine::ForCurrentProcess()->HasSwitch(switches::kEnablePinch);
   return pinch_allowed;
 }
 
+bool ShouldReleaseFrontSurface() {
+  static bool release_front_surface_allowed =
+      CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kEnableUIReleaseFrontSurface);
+  return release_front_surface_allowed;
+}
+
 }  // namespace
 
 // We have to implement the WindowObserver interface on a separate object
 // because clang doesn't like implementing multiple interfaces that have
 // methods with the same name. This object is owned by the
 // RenderWidgetHostViewAura.
 class RenderWidgetHostViewAura::WindowObserver : public aura::WindowObserver {
  public:
   explicit WindowObserver(RenderWidgetHostViewAura* view) : view_(view) {}
   virtual ~WindowObserver() {}
@@ skipping 61 matching lines @@
       ALLOW_THIS_IN_INITIALIZER_LIST(window_(new aura::Window(this))),
       in_shutdown_(false),
       is_fullscreen_(false),
       popup_parent_host_view_(NULL),
       popup_child_host_view_(NULL),
       is_loading_(false),
       text_input_type_(ui::TEXT_INPUT_TYPE_NONE),
       can_compose_inline_(true),
       has_composition_text_(false),
       current_surface_(0),
+      current_surface_is_protected_(true),
+      current_surface_in_use_by_compositor_(true),
+      pending_thumbnail_tasks_(0),
+      protection_state_id_(0),
+      surface_route_id_(0),
       paint_canvas_(NULL),
       synthetic_move_sent_(false),
       accelerated_compositing_state_changed_(false) {
   host_->SetView(this);
   window_observer_.reset(new WindowObserver(this));
   window_->AddObserver(window_observer_.get());
   aura::client::SetTooltipText(window_, &tooltip_);
   aura::client::SetActivationDelegate(window_, this);
 }
 
@@ skipping 31 matching lines @@
   window_->SetParent(NULL);
   Show();
   Focus();
 }
 
 RenderWidgetHost* RenderWidgetHostViewAura::GetRenderWidgetHost() const {
   return host_;
 }
 
 void RenderWidgetHostViewAura::WasRestored() {
+  if (!host_->IsHidden())
+    return;
   host_->WasRestored();
+
   if (!current_surface_ && host_->is_accelerated_compositing_active() &&
-      !released_front_lock_.get())
+      !released_front_lock_.get()) {
     released_front_lock_ = window_->GetRootWindow()->GetCompositorLock();
+  }
+
+  AdjustSurfaceProtection();
 }
 
 void RenderWidgetHostViewAura::WasHidden() {
+  if (host_->IsHidden())
+    return;
+
   host_->WasHidden();
+
   released_front_lock_ = NULL;
+
+  if (ShouldReleaseFrontSurface() &&
+      host_->is_accelerated_compositing_active()) {
+    current_surface_ = 0;
+    UpdateExternalTexture();
+  }
+
+  AdjustSurfaceProtection();
 }
 
 void RenderWidgetHostViewAura::SetSize(const gfx::Size& size) {
   SetBounds(gfx::Rect(window_->bounds().origin(), size));
 }
 
 void RenderWidgetHostViewAura::SetBounds(const gfx::Rect& rect) {
   if (window_->bounds().size() != rect.size() &&
       host_->is_accelerated_compositing_active()) {
     resize_locks_.push_back(make_linked_ptr(
@@ skipping 181 matching lines @@
     return;
 
   ImageTransportFactory* factory = ImageTransportFactory::GetInstance();
   GLHelper* gl_helper = factory->GetGLHelper(compositor);
   if (!gl_helper)
     return;
 
   unsigned char* addr = static_cast<unsigned char*>(
       output->getTopDevice()->accessBitmap(true).getPixels());
   scoped_callback_runner.Release();
+  // Wrap the callback with an internal handler so that we can inject our
+  // own completion handlers (where we can call AdjustSurfaceProtection).
+  base::Callback<void(bool)> wrapper_callback = base::Bind(
+      &RenderWidgetHostViewAura::CopyFromCompositingSurfaceFinished,
+      AsWeakPtr(),
+      callback);

[piman, 2012/07/25 19:56:51]

I believe the thumbnailer expects you to run the callback in all cases, even if
it's to report failure. Maybe double-check with mazda@
The risk here is that if the RWHVA gets deleted, the callback won't be sent. You
may have to keep a list of pending callbacks (add here, remove in
CopyFromCompositingSurfaceFinished) and run them with failure when the RWHVA
gets deleted.

+  ++pending_thumbnail_tasks_;
   gl_helper->CopyTextureTo(container->texture_id(),
                            container->size(),
                            size_in_pixel,
                            addr,
-                           callback);
+                           wrapper_callback);
 }
 
 void RenderWidgetHostViewAura::OnAcceleratedCompositingStateChange() {
   // Delay processing the state change until we either get a software frame if
   // switching to software mode or receive a buffers swapped notification
   // if switching to accelerated mode.
   // Sometimes (e.g. on a page load) the renderer will spuriously disable then
   // re-enable accelerated compositing, causing us to flash.
   // TODO(piman): factor the enable/disable accelerated compositing message into
   // the UpdateRect/AcceleratedSurfaceBuffersSwapped messages so that we have
@@ skipping 10 matching lines @@
     // care of it.
     window_->layer()->set_scale_content(
         !host_->is_accelerated_compositing_active());
 
     accelerated_compositing_state_changed_ = false;
   }
 
   if (current_surface_ != 0 && host_->is_accelerated_compositing_active()) {
     ui::Texture* container = image_transport_clients_[current_surface_];
     window_->SetExternalTexture(container);
-
-    released_front_lock_ = NULL;
+    current_surface_in_use_by_compositor_ = true;
 
     if (!container) {
       resize_locks_.clear();
     } else {
       typedef std::vector<linked_ptr<ResizeLock> > ResizeLockList;
       ResizeLockList::iterator it = resize_locks_.begin();
       while (it != resize_locks_.end()) {
         gfx::Size container_size = ConvertSizeToDIP(this,
             container->size());
         if ((*it)->expected_size() == container_size)
@@ skipping 16 matching lines @@
             it2->get()->UnlockCompositor();
           }
           if (!compositor->HasObserver(this))
             compositor->AddObserver(this);
         }
         resize_locks_.erase(resize_locks_.begin(), it);
       }
     }
   } else {
     window_->SetExternalTexture(NULL);
+    if (ShouldReleaseFrontSurface() &&
+        host_->is_accelerated_compositing_active()) {
+      // The current surface may have pipelined gl commands, so always wait for
+      // the next composite to start.  If the current surface is still null,
+      // then we really know its no longer in use.
+      ui::Compositor* compositor = GetCompositor();
+      if (compositor) {
+        on_compositing_will_start_callbacks_.push_back(
+            base::Bind(&RenderWidgetHostViewAura::
+                           SetSurfaceNotInUseByCompositor,
+                       AsWeakPtr()));
+        if (!compositor->HasObserver(this))
+          compositor->AddObserver(this);
+      }
+    }
     resize_locks_.clear();
   }
 }
 
 void RenderWidgetHostViewAura::AcceleratedSurfaceBuffersSwapped(
     const GpuHostMsg_AcceleratedSurfaceBuffersSwapped_Params& params_in_pixel,
     int gpu_host_id) {
+  surface_route_id_ = params_in_pixel.route_id;
+  // If protection state changed, then this swap is stale. We must still ACK but
+  // do not update current_surface_ since it may have been discarded.
+  if (params_in_pixel.protection_state_id &&
+      params_in_pixel.protection_state_id != protection_state_id_) {
+    DCHECK(!current_surface_);
+    if (!params_in_pixel.skip_ack)
+      InsertSyncPointAndACK(params_in_pixel.route_id, gpu_host_id, NULL);
+    return;
+  }
   current_surface_ = params_in_pixel.surface_handle;
+  // If we don't require an ACK that means the content is not a fresh updated
+  // new frame, rather we are just resetting our handle to some old content that
+  // we still hadn't discarded. Although we could display immediately, by not
+  // resetting the compositor lock here, we give us some time to get a fresh
+  // frame which means fewer content flashes.
+  if (!params_in_pixel.skip_ack)
+    released_front_lock_ = NULL;
+
   UpdateExternalTexture();
 
   ui::Compositor* compositor = GetCompositor();
   if (!compositor) {
     // We have no compositor, so we have no way to display the surface.
     // Must still send the ACK.
-    InsertSyncPointAndACK(params_in_pixel.route_id, gpu_host_id, NULL);
+    if (!params_in_pixel.skip_ack)
+      InsertSyncPointAndACK(params_in_pixel.route_id, gpu_host_id, NULL);
   } else {
+    DCHECK(image_transport_clients_.find(params_in_pixel.surface_handle) !=
+           image_transport_clients_.end());
     gfx::Size surface_size_in_pixel =
         image_transport_clients_[params_in_pixel.surface_handle]->size();
     gfx::Size surface_size = ConvertSizeToDIP(this,
                                                        surface_size_in_pixel);
     window_->SchedulePaintInRect(gfx::Rect(surface_size));
 
-    if (!resize_locks_.empty()) {
-      // If we are waiting for the resize, fast-track the ACK.
-      if (compositor->IsThreaded()) {
-        // We need the compositor thread to pick up the active buffer before
-        // ACKing.
-        on_compositing_did_commit_callbacks_.push_back(
+    if (!params_in_pixel.skip_ack) {
+      if (!resize_locks_.empty()) {
+        // If we are waiting for the resize, fast-track the ACK.
+        if (compositor->IsThreaded()) {
+          // We need the compositor thread to pick up the active buffer before
+          // ACKing.
+          on_compositing_did_commit_callbacks_.push_back(
+              base::Bind(&RenderWidgetHostViewAura::InsertSyncPointAndACK,
+                         params_in_pixel.route_id,
+                         gpu_host_id));
+          if (!compositor->HasObserver(this))
+            compositor->AddObserver(this);
+        } else {
+          // The compositor will pickup the active buffer during a draw, so we
+          // can ACK immediately.
+          InsertSyncPointAndACK(params_in_pixel.route_id, gpu_host_id,
+                                compositor);
+        }
+      } else {
+        // Add sending an ACK to the list of things to do OnCompositingWillStart
+        on_compositing_will_start_callbacks_.push_back(
             base::Bind(&RenderWidgetHostViewAura::InsertSyncPointAndACK,
                        params_in_pixel.route_id,
                        gpu_host_id));
         if (!compositor->HasObserver(this))
           compositor->AddObserver(this);
-      } else {
-        // The compositor will pickup the active buffer during a draw, so we
-        // can ACK immediately.
-        InsertSyncPointAndACK(params_in_pixel.route_id, gpu_host_id,
-                              compositor);
       }
-    } else {
-      // Add sending an ACK to the list of things to do OnCompositingWillStart
-      on_compositing_will_start_callbacks_.push_back(
-          base::Bind(&RenderWidgetHostViewAura::InsertSyncPointAndACK,
-                     params_in_pixel.route_id,
-                     gpu_host_id));
-      if (!compositor->HasObserver(this))
-        compositor->AddObserver(this);
     }
   }
 }
 
 void RenderWidgetHostViewAura::AcceleratedSurfacePostSubBuffer(
     const GpuHostMsg_AcceleratedSurfacePostSubBuffer_Params& params_in_pixel,
     int gpu_host_id) {
+  surface_route_id_ = params_in_pixel.route_id;
+  // If visible state changed, then this PSB is stale. We must still ACK but
+  // do not update current_surface_.
+  if (params_in_pixel.protection_state_id &&
+      params_in_pixel.protection_state_id != protection_state_id_) {
+    DCHECK(!current_surface_);
+    InsertSyncPointAndACK(params_in_pixel.route_id, gpu_host_id, NULL);
+    return;
+  }
   current_surface_ = params_in_pixel.surface_handle;
+  released_front_lock_ = NULL;
+  DCHECK(current_surface_);
   UpdateExternalTexture();
 
   ui::Compositor* compositor = GetCompositor();
   if (!compositor) {
     // We have no compositor, so we have no way to display the surface
     // Must still send the ACK
     InsertSyncPointAndACK(params_in_pixel.route_id, gpu_host_id, NULL);
   } else {
+    DCHECK(image_transport_clients_.find(params_in_pixel.surface_handle) !=
+           image_transport_clients_.end());
     gfx::Size surface_size_in_pixel =
         image_transport_clients_[params_in_pixel.surface_handle]->size();
 
     // Co-ordinates come in OpenGL co-ordinate space.
     // We need to convert to layer space.
     gfx::Rect rect_to_paint = ConvertRectToDIP(this, gfx::Rect(
         params_in_pixel.x,
         surface_size_in_pixel.height() - params_in_pixel.y -
             params_in_pixel.height,
         params_in_pixel.width,
@@ skipping 53 matching lines @@
   if (!surface) {
     LOG(ERROR) << "Failed to create ImageTransport texture";
     return;
   }
 
   image_transport_clients_[surface_handle] = surface;
 }
 
 void RenderWidgetHostViewAura::AcceleratedSurfaceRelease(
     uint64 surface_handle) {
+  DCHECK(image_transport_clients_.find(surface_handle) !=
+         image_transport_clients_.end());
   if (current_surface_ == surface_handle) {
     current_surface_ = 0;
     UpdateExternalTexture();
   }
   image_transport_clients_.erase(surface_handle);
 }
 
+void RenderWidgetHostViewAura::SetSurfaceNotInUseByCompositor(ui::Compositor*) {
+  if (current_surface_ || !host_->IsHidden())
+    return;
+  current_surface_in_use_by_compositor_ = false;
+  AdjustSurfaceProtection();
+}
+
+void RenderWidgetHostViewAura::AdjustSurfaceProtection() {
+  // If the current surface is non null, it is protected.
+  // If we are visible, it is protected.
+  // Otherwise, change to not proctected once done thumbnailing and compositing.
+  bool surface_is_protected =
+      current_surface_ ||
+      !host_->IsHidden() ||
+      (current_surface_is_protected_ &&
+          (pending_thumbnail_tasks_ || current_surface_in_use_by_compositor_));
+  if (current_surface_is_protected_ == surface_is_protected)
+    return;
+  current_surface_is_protected_ = surface_is_protected;
+  ++protection_state_id_;
+
+  if (!surface_route_id_ || !shared_surface_handle_.parent_gpu_process_id)
+    return;
+
+  RenderWidgetHostImpl::SendFrontSurfaceIsProtected(
+      surface_is_protected,
+      protection_state_id_,
+      surface_route_id_,
+      shared_surface_handle_.parent_gpu_process_id);
+}
+
+void RenderWidgetHostViewAura::CopyFromCompositingSurfaceFinished(
+    base::Callback<void(bool)> callback, bool result) {
+  --pending_thumbnail_tasks_;
+  AdjustSurfaceProtection();
+  callback.Run(result);
+}
+
 void RenderWidgetHostViewAura::SetBackground(const SkBitmap& background) {
   RenderWidgetHostViewBase::SetBackground(background);
   host_->SetBackground(background);
   window_->layer()->SetFillsBoundsOpaquely(background.isOpaque());
 }
 
 void RenderWidgetHostViewAura::GetScreenInfo(WebScreenInfo* results) {
   GetScreenInfoForWindow(results, window_);
 }
 
@@ skipping 585 matching lines @@
 void RenderWidgetHostViewAura::OnCompositingAborted(
     ui::Compositor* compositor) {
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // RenderWidgetHostViewAura, ImageTransportFactoryObserver implementation:
 
 void RenderWidgetHostViewAura::OnLostResources(ui::Compositor* compositor) {
   image_transport_clients_.clear();
   current_surface_ = 0;
+  protection_state_id_ = 0;
+  current_surface_is_protected_ = true;
+  current_surface_in_use_by_compositor_ = true;
+  surface_route_id_ = 0;
   UpdateExternalTexture();
   locks_pending_draw_.clear();
 
   DCHECK(!shared_surface_handle_.is_null());
   ImageTransportFactory* factory = ImageTransportFactory::GetInstance();
   factory->DestroySharedSurfaceHandle(shared_surface_handle_);
   shared_surface_handle_ = factory->CreateSharedSurfaceHandle(compositor);
   host_->CompositingSurfaceUpdated();
   host_->ScheduleComposite();
 }
@@ skipping 183 matching lines @@
     RenderWidgetHost* widget) {
   return new RenderWidgetHostViewAura(widget);
 }
 
 // static
 void RenderWidgetHostViewPort::GetDefaultScreenInfo(WebScreenInfo* results) {
   GetScreenInfoForWindow(results, NULL);
 }
 
 }  // namespace content