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_skia.h"
 #include "content/browser/renderer_host/dip_util.h"
 #include "content/browser/renderer_host/image_transport_client.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 104 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:
   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),
+      visibility_state_id_(0),
+      route_id_(0),
       paint_canvas_(NULL),
       synthetic_move_sent_(false),
       needs_update_texture_(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 51 matching lines @@
   window_->layer()->set_scale_content(false);
   Show();
   Focus();
 }
 
 RenderWidgetHost* RenderWidgetHostViewAura::GetRenderWidgetHost() const {
   return host_;
 }
 
 void RenderWidgetHostViewAura::DidBecomeSelected() {
+  if (host_->IsVisible())
+    return;
+
   host_->WasRestored();
+
+  ++visibility_state_id_;

[piman, 2012/06/12 20:59:48]

Why not do this in AdjustSurfaceProtection() before (and only if) sending the
message? The state id needs to increase any time the state changes - even if
it's not for visibility reason. BTW, I think it'd be better named
"protection_state_id" or something like that since that's really what it's
linked to.

[mmocny, 2012/06/12 21:25:51]

I need to increase state id before the Adjust function since the visibility
state id is tested for changes inside SetSurfaceNotInUseByCompositor to make
sure we dont have visibility ABA issues while delaying reset for compositing
callback.

I am assuming we will only flip protection as a result of visibility changes
(since right now, that is the only way we set/reset current_surface_), so it
really is a visibility state id (although visibility state id changes more often
than protection does, it always flips when we need it to).

On 2012/06/12 20:59:48, piman wrote:

+
+  if (!current_surface_ && host_->is_accelerated_compositing_active() &&
+      !released_front_lock_.get())
+    released_front_lock_ = window_->GetRootWindow()->GetCompositorLock();
+
+  AdjustSurfaceProtection();
 }
 
 void RenderWidgetHostViewAura::WasHidden() {
+  if (!host_->IsVisible())
+    return;
+
   host_->WasHidden();
+
+  ++visibility_state_id_;
+  released_front_lock_ = NULL;
+
+  if (ShouldReleaseFrontSurface()) {
+    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 142 matching lines @@
 BackingStore* RenderWidgetHostViewAura::AllocBackingStore(
     const gfx::Size& size) {
   return new BackingStoreSkia(host_, size);
 }
 
 void RenderWidgetHostViewAura::CopyFromCompositingSurface(
     const gfx::Size& size,
     skia::PlatformCanvas* output,
     base::Callback<void(bool)> callback) {
   base::ScopedClosureRunner scoped_callback_runner(base::Bind(callback, false));
+
   ui::Compositor* compositor = GetCompositor();
   if (!compositor)
     return;
 
   std::map<uint64, scoped_refptr<ImageTransportClient> >::iterator it =
       image_transport_clients_.find(current_surface_);
   if (it == image_transport_clients_.end())
     return;
 
   ImageTransportClient* container = it->second;
   DCHECK(container);
 
   gfx::Size size_in_pixel = content::ConvertSizeToPixel(this, size);
   if (!output->initialize(
       size_in_pixel.width(), size_in_pixel.height(), true))
     return;
 
   ImageTransportFactory* factory = ImageTransportFactory::GetInstance();
   content::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);
   gl_helper->CopyTextureTo(container->texture_id(),
                            container->size(),
                            size_in_pixel,
                            addr,
-                           callback);
+                           wrapper_callback);
+  ++pending_thumbnail_tasks_;

[piman, 2012/06/12 20:59:48]

do this before kicking the copy, in case the callback gets called synchronously
from the CopyTextureTo

+}
+
+void RenderWidgetHostViewAura::CopyFromCompositingSurfaceFinished(
+    base::Callback<void(bool)> callback, bool result) {
+  --pending_thumbnail_tasks_;
+  AdjustSurfaceProtection();
+  callback.Run(result);
 }
 
 void RenderWidgetHostViewAura::OnAcceleratedCompositingStateChange() {
   // Delay UpdateExternalTexture until we actually got a software frame.
   // 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
   // fewer inconsistent temporary states.
   needs_update_texture_ = true;
 }
 
 void RenderWidgetHostViewAura::UpdateExternalTexture() {
   needs_update_texture_ = false;
   if (current_surface_ != 0 &&
       host_->is_accelerated_compositing_active()) {
-
+    DCHECK(image_transport_clients_.find(current_surface_) !=
+           image_transport_clients_.end());
     ImageTransportClient* container =
         image_transport_clients_[current_surface_];
     if (container)
       container->Update();
     window_->SetExternalTexture(container);
+    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 = content::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);
+    ui::Compositor* compositor = GetCompositor();
+    if (!compositor->DrawPending()) {
+      current_surface_in_use_by_compositor_ = false;
+      AdjustSurfaceProtection();
+    } else {
+      on_compositing_ended_callbacks_.push_back(
+          base::Bind(&RenderWidgetHostViewAura::
+                         SetSurfaceNotInUseByCompositor,
+                     AsWeakPtr(),
+                     visibility_state_id_));
+      if (!compositor->HasObserver(this))
+        compositor->AddObserver(this);
+    }
     resize_locks_.clear();
   }
 }
 
 void RenderWidgetHostViewAura::AcceleratedSurfaceBuffersSwapped(
     const GpuHostMsg_AcceleratedSurfaceBuffersSwapped_Params& params_in_pixel,
     int gpu_host_id) {
+  // If visibility 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.visibility_state_id &&
+      params_in_pixel.visibility_state_id != visibility_state_id_) {
+    DCHECK(!current_surface_);
+    if (params_in_pixel.require_ack)

[piman, 2012/06/12 20:59:48]

nit: per sytle, needs braces if the body is >1 line

+      RenderWidgetHostImpl::AcknowledgeSwapBuffers(params_in_pixel.route_id,
+          gpu_host_id);
+    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 imedietally, 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.require_ack)
+    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.
-    RenderWidgetHostImpl::AcknowledgeSwapBuffers(params_in_pixel.route_id,
-        gpu_host_id);
+    if (params_in_pixel.require_ack)
+      RenderWidgetHostImpl::AcknowledgeSwapBuffers(params_in_pixel.route_id,
+          gpu_host_id);
   } 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 = content::ConvertSizeToDIP(this,
                                                        surface_size_in_pixel);
     window_->SchedulePaintInRect(gfx::Rect(surface_size));
 
-    if (!resize_locks_.empty() && !compositor->DrawPending()) {
-      // If we are waiting for the resize, fast-track the ACK.
-      // However only do so if we're not between the Draw() and the
-      // OnCompositingEnded(), because out-of-order execution in the GPU process
-      // might corrupt the "front buffer" for the currently issued frame.
-      RenderWidgetHostImpl::AcknowledgeSwapBuffers(
-          params_in_pixel.route_id, gpu_host_id);
-    } else {
-      // Add sending an ACK to the list of things to do OnCompositingEnded
-      on_compositing_ended_callbacks_.push_back(
-          base::Bind(&RenderWidgetHostImpl::AcknowledgeSwapBuffers,
-                     params_in_pixel.route_id, gpu_host_id));
-      if (!compositor->HasObserver(this))
-        compositor->AddObserver(this);
+    if (params_in_pixel.require_ack) {
+      if (!resize_locks_.empty() && !compositor->DrawPending()) {
+        // If we are waiting for the resize, fast-track the ACK.
+        // However only do so if we're not between the Draw() and the
+        // OnCompositingEnded(), because out-of-order execution in the GPU
+        // process might corrupt the "front buffer" for the currently issued
+        // frame.
+        RenderWidgetHostImpl::AcknowledgeSwapBuffers(
+            params_in_pixel.route_id, gpu_host_id);
+      } else {
+        // Add sending an ACK to the list of things to do OnCompositingEnded
+        on_compositing_ended_callbacks_.push_back(
+            base::Bind(&RenderWidgetHostImpl::AcknowledgeSwapBuffers,
+                       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) {
+  // If visible state changed, then this PSB is stale. We must still ACK but
+  // do not update current_surface_.
+  if (params_in_pixel.visibility_state_id &&
+      params_in_pixel.visibility_state_id != visibility_state_id_) {
+    DCHECK(!current_surface_);
+    RenderWidgetHostImpl::AcknowledgePostSubBuffer(params_in_pixel.route_id,
+        gpu_host_id);
+    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
     RenderWidgetHostImpl::AcknowledgePostSubBuffer(
         params_in_pixel.route_id, gpu_host_id);
   } 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 = content::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 26 matching lines @@
   // Aura doesn't use GetBackingStore for accelerated pages, so it doesn't
   // matter what is returned here as GetBackingStore is the only caller of this
   // method. TODO(jbates) implement this if other Aura code needs it.
   return false;
 }
 
 void RenderWidgetHostViewAura::AcceleratedSurfaceNew(
       int32 width_in_pixel,
       int32 height_in_pixel,
       uint64* surface_handle,
-      TransportDIB::Handle* shm_handle) {
+      TransportDIB::Handle* shm_handle,
+      int32 route_id) {
   ImageTransportFactory* factory = ImageTransportFactory::GetInstance();
   scoped_refptr<ImageTransportClient> surface(factory->CreateTransportClient(
         gfx::Size(width_in_pixel, height_in_pixel), surface_handle));
   if (!surface) {
     LOG(ERROR) << "Failed to create ImageTransportClient";
     return;
   }
   *shm_handle = surface->Handle();
 
   image_transport_clients_[*surface_handle] = surface;
+
+  route_id_ = route_id;
 }
 
 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(
+    uint32 expected_visibility_state_id) {
+  if (visibility_state_id_ != expected_visibility_state_id)
+    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.
+  // If we are not visible and current surface is null, still stay protected
+  // until we finish thumbnailing and compositing.
+  bool surface_is_protected =
+      current_surface_ ||
+      host_->IsVisible() ||
+      (current_surface_is_protected_ &&
+          (pending_thumbnail_tasks_ || GetCompositor()->DrawPending()));
+  if (current_surface_is_protected_ == surface_is_protected)
+    return;
+  current_surface_is_protected_ = surface_is_protected;
+
+  if (!route_id_ || !shared_surface_handle_.parent_gpu_process_id)
+    return;
+
+  RenderWidgetHostImpl::SendFrontSurfaceIsProtected(
+      surface_is_protected,
+      visibility_state_id_,
+      route_id_,
+      shared_surface_handle_.parent_gpu_process_id);
+}
+
 void RenderWidgetHostViewAura::SetBackground(const SkBitmap& background) {
   content::RenderWidgetHostViewBase::SetBackground(background);
   host_->SetBackground(background);
   window_->layer()->SetFillsBoundsOpaquely(background.isOpaque());
 }
 
 void RenderWidgetHostViewAura::GetScreenInfo(WebKit::WebScreenInfo* results) {
   GetScreenInfoForWindow(results, window_);
 }
 
@@ skipping 520 matching lines @@
 void RenderWidgetHostViewAura::OnCompositingAborted(
     ui::Compositor* compositor) {
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // RenderWidgetHostViewAura, ImageTransportFactoryObserver implementation:
 
 void RenderWidgetHostViewAura::OnLostResources(ui::Compositor* compositor) {
   image_transport_clients_.clear();
   current_surface_ = 0;
+  visibility_state_id_ = 0;
+  current_surface_is_protected_ = true;
+  current_surface_in_use_by_compositor_ = true;
+  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 126 matching lines @@
 RenderWidgetHostView* RenderWidgetHostView::CreateViewForWidget(
     RenderWidgetHost* widget) {
   return new RenderWidgetHostViewAura(widget);
 }
 
 // static
 void content::RenderWidgetHostViewPort::GetDefaultScreenInfo(
     WebKit::WebScreenInfo* results) {
   GetScreenInfoForWindow(results, NULL);
 }