Mac Overlays: Add GPU back-pressure

content/common/gpu/image_transport_surface_overlay_mac.mm

Index: content/common/gpu/image_transport_surface_overlay_mac.mm
diff --git a/content/common/gpu/image_transport_surface_overlay_mac.mm b/content/common/gpu/image_transport_surface_overlay_mac.mm
index 1a528333529330c9b8872a8f6c71be59970c170b..2287b4aa736a824764badb027d3e8ffcc08f20c1 100644
--- a/content/common/gpu/image_transport_surface_overlay_mac.mm
+++ b/content/common/gpu/image_transport_surface_overlay_mac.mm
@@ -4,27 +4,72 @@
 
 #include "content/common/gpu/image_transport_surface_overlay_mac.h"
 
-#include <OpenGL/gl.h>
+#include <IOSurface/IOSurface.h>
+#include <OpenGL/GL.h>
 
+// This type consistently causes problem on Mac, and needs to be dealt with
+// in a systemic way.
+// http://crbug.com/517208
+#ifndef GL_OES_EGL_image
+typedef void* GLeglImageOES;
+#endif
+
+#include "base/mac/scoped_cftyperef.h"
 #include "content/common/gpu/gpu_messages.h"
 #include "ui/accelerated_widget_mac/surface_handle_types.h"
 #include "ui/base/cocoa/animation_utils.h"
 #include "ui/base/cocoa/remote_layer_api.h"
 #include "ui/gfx/geometry/dip_util.h"
+#include "ui/gl/gl_fence_apple.h"
 #include "ui/gl/gl_image_io_surface.h"
+#include "ui/gl/scoped_api.h"
+#include "ui/gl/scoped_cgl.h"
+
+namespace {
+
+void CheckGLErrors(const char* msg) {
+  GLenum gl_error;
+  while ((gl_error = glGetError()) != GL_NO_ERROR) {
+    LOG(ERROR) << "OpenGL error hit " << msg << ": " << gl_error;
+  }
+}
+
+}  // namespace
 
 namespace content {
 
+class ImageTransportSurfaceOverlayMac::PendingSwap :
+    public base::RefCounted<PendingSwap> {
+ public:
+  PendingSwap() {}
+
+  // The IOSurface with new content for this swap.
+  base::ScopedCFTypeRef<IOSurfaceRef> io_surface;
+
+  // A fence object, and the CGL context it was issued in.
+  base::ScopedTypeRef<CGLContextObj> cgl_context;
+  scoped_ptr<gfx::GLFenceAPPLE> fence;
+
+  // The size of the full frame, in dip.
+  gfx::Size dip_size;
+
+  std::vector<ui::LatencyInfo> latency_info;
+
+ protected:
+  friend class base::RefCounted<PendingSwap>;
+
+  virtual ~PendingSwap() { DCHECK(!fence); }
+};
+
 ImageTransportSurfaceOverlayMac::ImageTransportSurfaceOverlayMac(
     GpuChannelManager* manager,
     GpuCommandBufferStub* stub,
     gfx::PluginWindowHandle handle)
-    : scale_factor_(1), pending_overlay_image_(nullptr) {
+    : scale_factor_(1), pending_overlay_image_(nullptr), weak_factory_(this) {
   helper_.reset(new ImageTransportHelper(this, manager, stub, handle));
 }
 
 ImageTransportSurfaceOverlayMac::~ImageTransportSurfaceOverlayMac() {
-  gfx::GLImageIOSurface::SetLayerForWidget(widget_, nil);
 }
 
 bool ImageTransportSurfaceOverlayMac::Initialize() {
@@ -37,61 +82,153 @@ bool ImageTransportSurfaceOverlayMac::Initialize() {
   ca_context_.reset(
       [[CAContext contextWithCGSConnection:connection_id options:@{}] retain]);
   layer_.reset([[CALayer alloc] init]);
+  [layer_ setGeometryFlipped:YES];
   [ca_context_ setLayer:layer_];
 
-  // Register the CALayer so that it can be picked up in GLImageIOSurface.
-  static intptr_t previous_widget = 0;
-  previous_widget += 1;
-  widget_ = reinterpret_cast<gfx::AcceleratedWidget>(previous_widget);
-  gfx::GLImageIOSurface::SetLayerForWidget(widget_, layer_);
-
   return true;
 }
 
-void ImageTransportSurfaceOverlayMac::Destroy() {}
+void ImageTransportSurfaceOverlayMac::Destroy() {
+  FinishAllPendingSwaps();
+}
 
 bool ImageTransportSurfaceOverlayMac::IsOffscreen() {
   return false;
 }
 
-gfx::SwapResult ImageTransportSurfaceOverlayMac::SwapBuffers() {
+gfx::SwapResult ImageTransportSurfaceOverlayMac::SwapBuffersInternal(
+    const gfx::Rect& pixel_damage_rect) {
   TRACE_EVENT0("gpu", "ImageTransportSurfaceOverlayMac::SwapBuffers");
 
-  // A flush is required to ensure that all content appears in the layer.
-  {
-    TRACE_EVENT0("gpu", "ImageTransportSurfaceOverlayMac::glFlush");
-    glFlush();
-  }
+  // The remainder of the function will populate the PendingSwap structure and
+  // then enqueue it.
+  scoped_refptr<PendingSwap> this_swap(new PendingSwap);
+  this_swap->latency_info.swap(latency_info_);
 
   // There should exist only one overlay image, and it should cover the whole
   // surface.
   DCHECK(pending_overlay_image_);
   if (pending_overlay_image_) {
-    TRACE_EVENT0("gpu", "ImageTransportSurfaceOverlayMac::setContents");
-    ScopedCAActionDisabler disabler;
-    gfx::Rect dip_bounds = gfx::ConvertRectToDIP(
-        scale_factor_, gfx::Rect(pixel_size_));
-    gfx::RectF crop_rect(0, 0, 1, 1);
-    pending_overlay_image_->ScheduleOverlayPlane(
-        widget_, 0, gfx::OVERLAY_TRANSFORM_NONE, dip_bounds, crop_rect);
+    gfx::GLImageIOSurface* pending_overlay_image_io_surface =
+        static_cast<gfx::GLImageIOSurface*>(pending_overlay_image_);
+    this_swap->io_surface = pending_overlay_image_io_surface->io_surface();
     pending_overlay_image_ = nullptr;
   }
 
+  // A flush is required to ensure that all content appears in the layer.
+  {
+    gfx::ScopedSetGLToRealGLApi scoped_set_gl_api;
+    TRACE_EVENT1("gpu", "ImageTransportSurfaceOverlayMac::glFlush", "surface",
+                 this_swap->io_surface.get());
+    CheckGLErrors("before flushing frame");
+    this_swap->cgl_context.reset(CGLGetCurrentContext(),
+                                base::scoped_policy::RETAIN);
+    this_swap->fence.reset(new gfx::GLFenceAPPLE);
+    CheckGLErrors("while flushing frame");
+  }
+
+  this_swap->dip_size = gfx::ConvertSizeToDIP(scale_factor_, pixel_size_);
+  pending_swaps_.push_back(this_swap);
+
+  PostCheckAndDisplayPendingSwaps();
+  return gfx::SwapResult::SWAP_ACK;
+}
+
+void ImageTransportSurfaceOverlayMac::CheckAndDisplayPendingSwaps(
+    bool force_immediate_display) {
+  TRACE_EVENT0("gpu",
+               "ImageTransportSurfaceOverlayMac::CheckAndDisplayPendingSwaps");
+  if (pending_swaps_.empty())
+    return;
+
+  // Check if the pending work has finished (and early-out if it is not, and
+  // this is not forced).
+  scoped_refptr<PendingSwap> this_swap = pending_swaps_.front();
+  {
+    gfx::ScopedSetGLToRealGLApi scoped_set_gl_api;
+    gfx::ScopedCGLSetCurrentContext scoped_set_current(this_swap->cgl_context);
+
+    CheckGLErrors("before testing fence");
+    bool result = this_swap->fence->HasCompleted();
+    CheckGLErrors("after testing fence");
+    if (!result && !force_immediate_display) {
+      PostCheckAndDisplayPendingSwaps();
+      TRACE_EVENT1("gpu", "ImageTransportSurfaceOverlayMac::fenceNotReady",
+                   "surface", this_swap->io_surface.get());
+      return;
+    }
+    this_swap->fence.reset();
+    CheckGLErrors("while deleting fence");
+  }
+
+  // Update the CALayer hierarchy.
+  {
+    TRACE_EVENT1("gpu", "ImageTransportSurfaceOverlayMac::setContents",
+                 "surface", this_swap->io_surface.get());
+    ScopedCAActionDisabler disabler;
+    id new_contents = static_cast<id>(this_swap->io_surface.get());
+    [layer_ setContents:new_contents];
+    CGRect new_frame = gfx::Rect(this_swap->dip_size).ToCGRect();
+    if (!CGRectEqualToRect([layer_ frame], new_frame))
+      [layer_ setFrame:new_frame];
+  }
+
+  // Remove this swap from the queue.
+  pending_swaps_.pop_front();
+
+  // Send acknowledgement to the browser.
   GpuHostMsg_AcceleratedSurfaceBuffersSwapped_Params params;
   params.surface_handle =
       ui::SurfaceHandleFromCAContextID([ca_context_ contextId]);
   params.size = pixel_size_;
   params.scale_factor = scale_factor_;
-  params.latency_info.swap(latency_info_);
+  params.latency_info.swap(this_swap->latency_info);
   helper_->SendAcceleratedSurfaceBuffersSwapped(params);
-  return gfx::SwapResult::SWAP_ACK;
+}
+
+void ImageTransportSurfaceOverlayMac::PostCheckAndDisplayPendingSwaps() {
+  bool force_immediate_display = true;
+  base::TimeDelta delay;
+  if (display_link_mac_) {
+    base::TimeTicks timebase;
+    base::TimeDelta interval;
+    if (display_link_mac_->GetVSyncParameters(&timebase, &interval)) {
+      base::TimeTicks now = base::TimeTicks::Now();
+      // Make the timer fire halfway through the vsync interval (since that
+      // makes actual vsync alignment the most likely).
+      timebase -= interval / 2;
+      // Make sure that timebase is before now (to simplify the below
+      // computations).
+      if (timebase >= now)
+        timebase -= (1 + (timebase - now) / interval) * interval;
+      // Compute the target time.
+      base::TimeTicks target =
+          timebase + (1 + (now - timebase) / interval) * interval;
+      delay = target - now;
+      force_immediate_display = false;
+    }
+  }
+  base::MessageLoop::current()->PostDelayedTask(
+      FROM_HERE,
+      base::Bind(&ImageTransportSurfaceOverlayMac::CheckAndDisplayPendingSwaps,
+                     weak_factory_.GetWeakPtr(), force_immediate_display),
+                 delay);
+}
+
+void ImageTransportSurfaceOverlayMac::FinishAllPendingSwaps() {
+  while (!pending_swaps_.empty())
+    CheckAndDisplayPendingSwaps(true);
+}
+
+gfx::SwapResult ImageTransportSurfaceOverlayMac::SwapBuffers() {
+  return SwapBuffersInternal(gfx::Rect(pixel_size_));
 }
 
 gfx::SwapResult ImageTransportSurfaceOverlayMac::PostSubBuffer(int x,
                                                                int y,
                                                                int width,
                                                                int height) {
-  return SwapBuffers();
+  return SwapBuffersInternal(gfx::Rect(x, y, width, height));
 }
 
 bool ImageTransportSurfaceOverlayMac::SupportsPostSubBuffer() {
@@ -129,10 +266,18 @@ bool ImageTransportSurfaceOverlayMac::IsSurfaceless() const {
 }
 
 void ImageTransportSurfaceOverlayMac::OnBufferPresented(
-    const AcceleratedSurfaceMsg_BufferPresented_Params& params) {}
+    const AcceleratedSurfaceMsg_BufferPresented_Params& params) {
+  if (display_link_mac_ &&
+      display_link_mac_->display_id() == params.display_id_for_vsync)
+    return;
+  display_link_mac_ = ui::DisplayLinkMac::GetForDisplay(
+      params.display_id_for_vsync);
+}
 
 void ImageTransportSurfaceOverlayMac::OnResize(gfx::Size pixel_size,
                                                float scale_factor) {
+  // Flush through any pending frames.
+  FinishAllPendingSwaps();
   pixel_size_ = pixel_size;
   scale_factor_ = scale_factor;
 }