[ozone] Keep the queue of surfaceless buffers inside gl_surface_ozone

ui/gl/gl_surface_ozone.cc

 // Copyright 2014 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 "ui/gl/gl_surface.h"
 
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/location.h"
 #include "base/logging.h"
@@ skipping 105 matching lines @@
 class GL_EXPORT GLSurfaceOzoneSurfaceless : public SurfacelessEGL {
  public:
   GLSurfaceOzoneSurfaceless(scoped_ptr<ui::SurfaceOzoneEGL> ozone_surface,
                             AcceleratedWidget widget)
       : SurfacelessEGL(gfx::Size()),
         ozone_surface_(ozone_surface.Pass()),
         widget_(widget),
         has_implicit_external_sync_(
             HasEGLExtension("EGL_ARM_implicit_external_sync")),
         last_swap_buffers_result_(true),
+        swap_buffers_pending_(false),
         weak_factory_(this) {
     unsubmitted_frames_.push_back(new PendingFrame());
   }
 
   bool Initialize() override {
     if (!SurfacelessEGL::Initialize())
       return false;
     vsync_provider_ = ozone_surface_->CreateVSyncProvider();
     if (!vsync_provider_)
       return false;
@@ skipping 38 matching lines @@
   bool IsOffscreen() override { return false; }
   VSyncProvider* GetVSyncProvider() override { return vsync_provider_.get(); }
   bool SupportsPostSubBuffer() override { return true; }
   bool PostSubBuffer(int x, int y, int width, int height) override {
     // The actual sub buffer handling is handled at higher layers.
     SwapBuffers();
     return true;
   }
   bool SwapBuffersAsync(const SwapCompletionCallback& callback) override {
     glFlush();
+
+    base::Closure surface_swap_callback =
+        base::Bind(&GLSurfaceOzoneSurfaceless::SwapCompleted,
+                   weak_factory_.GetWeakPtr(), callback);
+
+    PendingFrame* frame = unsubmitted_frames_.back();
+    frame->callback = surface_swap_callback;
+    unsubmitted_frames_.push_back(new PendingFrame());
+
     // TODO: the following should be replaced by a per surface flush as it gets
     // implemented in GL drivers.
     if (has_implicit_external_sync_) {
       // If last swap failed, don't try to schedule new ones.
       if (!last_swap_buffers_result_) {
         last_swap_buffers_result_ = true;
         return false;
       }
 
       EGLSyncKHR fence = InsertFence();
       if (!fence)
         return false;
 
       base::Closure fence_wait_task =
           base::Bind(&WaitForFence, GetDisplay(), fence);
 
-      PendingFrame* frame = unsubmitted_frames_.back();
-      frame->callback = callback;
       base::Closure fence_retired_callback =
           base::Bind(&GLSurfaceOzoneSurfaceless::FenceRetired,
                      weak_factory_.GetWeakPtr(), fence, frame);
 
       base::WorkerPool::PostTaskAndReply(FROM_HERE, fence_wait_task,
                                          fence_retired_callback, false);
-      unsubmitted_frames_.push_back(new PendingFrame());
       return true;
     } else if (ozone_surface_->IsUniversalDisplayLinkDevice()) {

[spang, 2015/04/21 19:39:36]

Can you fix the style guide violation here?

No else {} after return.

       glFinish();
     }
-    unsubmitted_frames_.back()->ScheduleOverlayPlanes(widget_);
-    unsubmitted_frames_.back()->overlays.clear();
-    return ozone_surface_->OnSwapBuffersAsync(callback);
+
+    frame->ready = true;
+    SubmitFrame();
+    return last_swap_buffers_result_;
   }
   bool PostSubBufferAsync(int x,
                           int y,
                           int width,
                           int height,
                           const SwapCompletionCallback& callback) override {
     return SwapBuffersAsync(callback);
   }
 
  protected:
@@ skipping 32 matching lines @@
     }
     bool ready;
     std::vector<Overlay> overlays;
     SwapCompletionCallback callback;
   };
 
   ~GLSurfaceOzoneSurfaceless() override {
     Destroy();  // EGL surface must be destroyed before SurfaceOzone
   }
 
-  void SubmitFrames() {
-    while (!unsubmitted_frames_.empty() && unsubmitted_frames_.front()->ready) {
-      PendingFrame* frame = unsubmitted_frames_.front();
+  void SubmitFrame() {
+    DCHECK(!unsubmitted_frames_.empty());
+
+    if (unsubmitted_frames_.front()->ready && !swap_buffers_pending_) {
+      scoped_ptr<PendingFrame> frame(unsubmitted_frames_.front());
+      unsubmitted_frames_.weak_erase(unsubmitted_frames_.begin());
+      swap_buffers_pending_ = true;
+
       last_swap_buffers_result_ =
-          last_swap_buffers_result_ && frame->ScheduleOverlayPlanes(widget_) &&
+          frame->ScheduleOverlayPlanes(widget_) &&
           ozone_surface_->OnSwapBuffersAsync(frame->callback);
-      unsubmitted_frames_.erase(unsubmitted_frames_.begin());
     }
   }
 
   EGLSyncKHR InsertFence() {
     const EGLint attrib_list[] = {EGL_SYNC_CONDITION_KHR,
                                   EGL_SYNC_PRIOR_COMMANDS_IMPLICIT_EXTERNAL_ARM,
                                   EGL_NONE};
     return eglCreateSyncKHR(GetDisplay(), EGL_SYNC_FENCE_KHR, attrib_list);
   }
 
   void FenceRetired(EGLSyncKHR fence, PendingFrame* frame) {
     eglDestroySyncKHR(GetDisplay(), fence);
     frame->ready = true;
-    SubmitFrames();
+    SubmitFrame();
+  }
+
+  void SwapCompleted(const SwapCompletionCallback& callback) {
+    callback.Run();
+    swap_buffers_pending_ = false;
+
+    SubmitFrame();
   }
 
   // The native surface. Deleting this is allowed to free the EGLNativeWindow.
   scoped_ptr<ui::SurfaceOzoneEGL> ozone_surface_;
   AcceleratedWidget widget_;
   scoped_ptr<VSyncProvider> vsync_provider_;
   ScopedVector<PendingFrame> unsubmitted_frames_;
   bool has_implicit_external_sync_;
   bool last_swap_buffers_result_;

[spang, 2015/04/21 19:39:36]

Can someone explain what last_swap_buffers_result_ is for?

+  bool swap_buffers_pending_;
 
   base::WeakPtrFactory<GLSurfaceOzoneSurfaceless> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(GLSurfaceOzoneSurfaceless);
 };
 
 // This provides surface-like semantics implemented through surfaceless.
 // A framebuffer is bound automatically.
 class GL_EXPORT GLSurfaceOzoneSurfacelessSurfaceImpl
     : public GLSurfaceOzoneSurfaceless {
@@ skipping 255 matching lines @@
       NOTREACHED();
       return NULL;
   }
 }
 
 EGLNativeDisplayType GetPlatformDefaultEGLNativeDisplay() {
   return ui::SurfaceFactoryOzone::GetInstance()->GetNativeDisplay();
 }
 
 }  // namespace gfx