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

content/common/gpu/texture_image_transport_surface.cc

Index: content/common/gpu/texture_image_transport_surface.cc
diff --git a/content/common/gpu/texture_image_transport_surface.cc b/content/common/gpu/texture_image_transport_surface.cc
index e9649f539a8c9c7ec355f597cb2655be0498d84f..63e8f5dd8d2986900e5e9d7b2b86ba35071fca05 100644
--- a/content/common/gpu/texture_image_transport_surface.cc
+++ b/content/common/gpu/texture_image_transport_surface.cc
@@ -56,7 +56,9 @@ TextureImageTransportSurface::TextureImageTransportSurface(
     const gfx::GLSurfaceHandle& handle)
       : fbo_id_(0),
         front_(0),
-        stub_destroyed_(false) {
+        stub_destroyed_(false),
+        backbuffer_allocated_(true),
+        frontbuffer_allocated_(true) {
   GpuChannel* parent_channel = manager->LookupChannel(handle.parent_client_id);
   DCHECK(parent_channel);
   GpuCommandBufferStub* parent_stub = parent_channel->LookupCommandBuffer(
@@ -129,7 +131,7 @@ bool TextureImageTransportSurface::OnMakeCurrent(gfx::GLContext* context) {
   if (!fbo_id_) {
     glGenFramebuffersEXT(1, &fbo_id_);
     glBindFramebufferEXT(GL_FRAMEBUFFER, fbo_id_);
-    CreateBackTexture(gfx::Size(1, 1));
+    CreateTexture(back(), gfx::Size(1, 1));
 
 #ifndef NDEBUG
     GLenum status = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER);
@@ -147,19 +149,26 @@ unsigned int TextureImageTransportSurface::GetBackingFrameBufferObject() {
   return fbo_id_;
 }
 
-void TextureImageTransportSurface::SetBufferAllocation(
-    BufferAllocationState state) {
+void TextureImageTransportSurface::SetBackbufferAllocation(bool allocated) {
+  if (backbuffer_allocated_ == allocated)
+    return;
+  if (!helper_->MakeCurrent())
+    return;
+  if (allocated)
+    CreateTexture(back(), textures_[back()].size);
+  else
+    RequestReleaseTexture(back());
+}
+
+void TextureImageTransportSurface::SetFrontbufferAllocation(bool allocated) {
+  if (frontbuffer_allocated_ == allocated)
+    return;
   if (!helper_->MakeCurrent())
     return;
-  switch (state) {
-    case BUFFER_ALLOCATION_FRONT_AND_BACK:
-      CreateBackTexture(textures_[back()].size);
-      break;
-    case BUFFER_ALLOCATION_FRONT_ONLY:
-    case BUFFER_ALLOCATION_NONE:
-      ReleaseBackTexture();
-      break;
-  };
+  if (allocated)
+    CreateTexture(front(), textures_[front()].size);

[mmocny, 2012/04/12 16:41:27]

I am playing with delaying this recreation until after the next
swap/postsubbuffer.  Otherwise, we tell the browser we have a new surface, but
its contents are empty and we display a blank frame (flash white).
Also, we have an open issue to delay switching tabs until after frontbuffer is
valid -- and since the browser has no way of knowing that contents are empty --
delaying AcceleratedSurfaceNew seems like the best option.

+  else
+    RequestReleaseTexture(front());
 }
 
 void* TextureImageTransportSurface::GetShareHandle() {
@@ -175,7 +184,7 @@ void* TextureImageTransportSurface::GetConfig() {
 }
 
 void TextureImageTransportSurface::OnResize(gfx::Size size) {
-  CreateBackTexture(size);
+  CreateTexture(back(), size);
 }
 
 void TextureImageTransportSurface::OnWillDestroyStub(
@@ -189,14 +198,19 @@ void TextureImageTransportSurface::OnWillDestroyStub(
 }
 
 bool TextureImageTransportSurface::SwapBuffers() {
+  DCHECK(backbuffer_allocated_);
+  if (!frontbuffer_allocated_) {
+    previous_damage_rect_ = gfx::Rect(textures_[back()].size);
+    return true;
+  }
   glFlush();
   front_ = back();
-  previous_damage_rect_ = gfx::Rect(textures_[front_].size);
+  previous_damage_rect_ = gfx::Rect(textures_[front()].size);
 
-  DCHECK(textures_[front_].client_id != 0);
+  DCHECK(textures_[front()].client_id != 0);
 
   GpuHostMsg_AcceleratedSurfaceBuffersSwapped_Params params;
-  params.surface_handle = textures_[front_].client_id;
+  params.surface_handle = textures_[front()].client_id;
   helper_->SendAcceleratedSurfaceBuffersSwapped(params);
   helper_->SetScheduled(false);
   return true;
@@ -204,6 +218,11 @@ bool TextureImageTransportSurface::SwapBuffers() {
 
 bool TextureImageTransportSurface::PostSubBuffer(
     int x, int y, int width, int height) {
+  DCHECK(backbuffer_allocated_);
+  if (!frontbuffer_allocated_) {
+    previous_damage_rect_ = gfx::Rect(textures_[back()].size);

[mmocny, 2012/04/12 16:41:27]

I think I got this backwards, previous_damage_rect_ should become empty here.

As a coincidence it doesn't matter, because we only recreate frontbuffer before
recreating backbuffer and redrawing a whole frame.

+    return true;
+  }
   if (!parent_stub_.get())
     return false;
 
@@ -212,13 +231,13 @@ bool TextureImageTransportSurface::PostSubBuffer(
     return false;
   int back_texture_service_id = info->service_id();
 
-  info = GetParentInfo(textures_[front_].client_id);
+  info = GetParentInfo(textures_[front()].client_id);
   if (!info)
     return false;
   int front_texture_service_id = info->service_id();
 
   gfx::Size expected_size = textures_[back()].size;
-  bool surfaces_same_size = textures_[front_].size == expected_size;
+  bool surfaces_same_size = textures_[front()].size == expected_size;
 
   const gfx::Rect new_damage_rect(x, y, width, height);
 
@@ -254,7 +273,7 @@ bool TextureImageTransportSurface::PostSubBuffer(
   front_ = back();
 
   GpuHostMsg_AcceleratedSurfacePostSubBuffer_Params params;
-  params.surface_handle = textures_[front_].client_id;
+  params.surface_handle = textures_[front()].client_id;
   params.x = x;
   params.y = y;
   params.width = width;
@@ -287,12 +306,20 @@ void TextureImageTransportSurface::OnNewSurfaceACK(
     uint64 surface_handle, TransportDIB::Handle /*shm_handle*/) {
 }
 
+void TextureImageTransportSurface::OnReleaseSurfaceACK(
+    uint64 surface_id, bool success) {
+  if (success)
+    ReleaseTexture(textures_[front()].client_id == surface_id ?
+                   front() : back());
+  helper_->SetScheduled(true);
+}
+
 void TextureImageTransportSurface::OnBuffersSwappedACK() {
   if (helper_->MakeCurrent()) {
-    if (textures_[front_].size != textures_[back()].size) {
-      CreateBackTexture(textures_[front_].size);
+    if (textures_[front()].size != textures_[back()].size) {
+      CreateTexture(back(), textures_[front()].size);
     } else {
-      AttachBackTextureToFBO();
+      AttachTextureToFBO(back());
     }
   }
 
@@ -309,10 +336,23 @@ void TextureImageTransportSurface::OnResizeViewACK() {
   NOTREACHED();
 }
 
-void TextureImageTransportSurface::ReleaseBackTexture() {
+void TextureImageTransportSurface::RequestReleaseTexture(int id) {
+  Texture& texture = textures_[id];
+  if (!texture.sent_to_client) {
+    ReleaseTexture(id);
+    return;
+  }
+  GpuHostMsg_AcceleratedSurfaceRelease_Params params;
+  params.identifier = texture.client_id;
+  helper_->SendAcceleratedSurfaceRelease(params);
+  helper_->SetScheduled(false);
+}
+
+void TextureImageTransportSurface::ReleaseTexture(int id) {
   if (!parent_stub_.get())
     return;
-  TextureInfo* info = GetParentInfo(textures_[back()].client_id);
+  Texture& texture = textures_[id];
+  TextureInfo* info = GetParentInfo(texture.client_id);
   if (!info)
     return;
 
@@ -327,12 +367,18 @@ void TextureImageTransportSurface::ReleaseBackTexture() {
   }
   glFlush();
   CHECK_GL_ERROR();
+  texture.sent_to_client = false;
+  if (id == front())
+    frontbuffer_allocated_ = false;
+  else
+    backbuffer_allocated_ = false;
 }
 
-void TextureImageTransportSurface::CreateBackTexture(const gfx::Size& size) {
+void TextureImageTransportSurface::CreateTexture(
+    int id, const gfx::Size& size) {
   if (!parent_stub_.get())
     return;
-  Texture& texture = textures_[back()];
+  Texture& texture = textures_[id];
   TextureInfo* info = GetParentInfo(texture.client_id);
   if (!info)
     return;
@@ -377,7 +423,7 @@ void TextureImageTransportSurface::CreateBackTexture(const gfx::Size& size) {
     CHECK_GL_ERROR();
   }
 
-  AttachBackTextureToFBO();
+  AttachTextureToFBO(id);
 
   GpuHostMsg_AcceleratedSurfaceNew_Params params;
   params.width = size.width();
@@ -385,12 +431,17 @@ void TextureImageTransportSurface::CreateBackTexture(const gfx::Size& size) {
   params.surface_handle = texture.client_id;
   helper_->SendAcceleratedSurfaceNew(params);
   texture.sent_to_client = true;
+
+  if (id == front())
+    frontbuffer_allocated_ = true;
+  else
+    backbuffer_allocated_ = true;
 }
 
-void TextureImageTransportSurface::AttachBackTextureToFBO() {
+void TextureImageTransportSurface::AttachTextureToFBO(int id) {
   if (!parent_stub_.get())
     return;
-  TextureInfo* info = GetParentInfo(textures_[back()].client_id);
+  TextureInfo* info = GetParentInfo(textures_[id].client_id);
   if (!info)
     return;