Implement commit for unaccelerated canvas with GPU compositing

third_party/WebKit/Source/platform/graphics/OffscreenCanvasFrameDispatcherImpl.cpp

 // Copyright 2016 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 "platform/graphics/OffscreenCanvasFrameDispatcherImpl.h"
 
 #include "cc/output/compositor_frame.h"
 #include "cc/output/delegated_frame_data.h"
 #include "cc/quads/render_pass.h"
 #include "cc/quads/shared_quad_state.h"
 #include "cc/quads/solid_color_draw_quad.h"
 #include "cc/quads/texture_draw_quad.h"
 #include "cc/resources/returned_resource.h"
+#include "gpu/command_buffer/client/gles2_interface.h"
+#include "platform/RuntimeEnabledFeatures.h"
+#include "platform/graphics/gpu/SharedGpuContext.h"
 #include "platform/RuntimeEnabledFeatures.h"
 #include "public/platform/InterfaceProvider.h"
 #include "public/platform/Platform.h"
 #include "public/platform/modules/offscreencanvas/offscreen_canvas_surface.mojom-blink.h"
 #include "third_party/khronos/GLES2/gl2.h"
+#include "third_party/khronos/GLES2/gl2ext.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "third_party/skia/include/core/SkImage.h"
 #include "third_party/skia/include/core/SkXfermode.h"
 #include "ui/gfx/geometry/rect.h"
 #include "ui/gfx/transform.h"
+#include "wtf/typed_arrays/ArrayBuffer.h"
+#include "wtf/typed_arrays/Uint8Array.h"
 
 namespace blink {
 
 OffscreenCanvasFrameDispatcherImpl::OffscreenCanvasFrameDispatcherImpl(
     uint32_t clientId,
     uint32_t localId,
     uint64_t nonce,
     int width,
     int height)
     : m_surfaceId(cc::SurfaceId(cc::FrameSinkId(clientId, 0 /* sink_id */),
                                 localId,
                                 nonce)),
       m_width(width),
       m_height(height),
       m_nextResourceId(1u),
       m_binding(this) {
   DCHECK(!m_sink.is_bound());
   mojom::blink::OffscreenCanvasCompositorFrameSinkProviderPtr provider;
   Platform::current()->interfaceProvider()->getInterface(
       mojo::GetProxy(&provider));
   provider->CreateCompositorFrameSink(m_surfaceId,
                                       m_binding.CreateInterfacePtrAndBind(),
                                       mojo::GetProxy(&m_sink));
 }
 
+// Case 1: both canvas and compositor are not gpu accelerated.
+void OffscreenCanvasFrameDispatcherImpl::setTransferableResourceCase1(
+    cc::TransferableResource& resource,
+    RefPtr<StaticBitmapImage> image) {
+  std::unique_ptr<cc::SharedBitmap> bitmap =
+      Platform::current()->allocateSharedBitmap(IntSize(m_width, m_height));
+  if (!bitmap)
+    return;
+  unsigned char* pixels = bitmap->pixels();
+  DCHECK(pixels);
+  SkImageInfo imageInfo = SkImageInfo::Make(
+      m_width, m_height, kN32_SkColorType,
+      image->isPremultiplied() ? kPremul_SkAlphaType : kUnpremul_SkAlphaType);
+  // TODO(xlai): Optimize to avoid copying pixels. See crbug.com/651456.
+  image->imageForCurrentFrame()->readPixels(imageInfo, pixels,
+                                            imageInfo.minRowBytes(), 0, 0);
+  resource.mailbox_holder.mailbox = bitmap->id();
+  resource.mailbox_holder.texture_target = 0;
+  resource.is_software = true;
+
+  // Hold ref to |bitmap|, to keep it alive until the browser ReturnResources.
+  // It guarantees that the shared bitmap is not re-used or deleted.
+  m_sharedBitmaps.add(m_nextResourceId, std::move(bitmap));
+}
+
+// Case 2: canvas is not gpu-accelerated, but compositor is
+void OffscreenCanvasFrameDispatcherImpl::setTransferableResourceCase2(
+    cc::TransferableResource& resource,
+    RefPtr<StaticBitmapImage> image) {
+  // TODO(xidachen): When committing the first frame, there is no instance of SharedGpuContext
+  // yet, calling SharedGpuContext::gl() will trigger a creation of an instace, which requires
+  // to create a WebGraphicsContext3DProvider. This process is quite expensive, because
+  // WebGraphicsContext3DProvider can only be constructed on the main thread, and bind to the
+  // worker thread if commit() is called on worker. In the subsequent frame, we should already
+  // have a SharedGpuContext, then getting the gl interface should not be expensive.
+  // Try to optimize the first frame in the future.

[Justin Novosad, 2016/10/04 14:20:48]

You need a crbug for this. There is a potential for an unexpected deadlock here.
 For example, If the main thread is waiting on a spinlock (possibly implemented
on top a SharedArrayBuffer) that is to be unlocked by a worker after commit(),
the browser should not hang.

[xidachen, 2016/10/04 14:43:06]

Done.

+  gpu::gles2::GLES2Interface* gl = SharedGpuContext::gl();
+
+  SkImageInfo info = SkImageInfo::Make(
+      m_width, m_height, kN32_SkColorType,
+      image->isPremultiplied() ? kPremul_SkAlphaType : kUnpremul_SkAlphaType);
+  RefPtr<ArrayBuffer> dstBuffer =
+      ArrayBuffer::createOrNull(m_width * m_height, info.bytesPerPixel());
+  // If it fails to create a buffer for copying the pixel data, then exit early.
+  if (!dstBuffer)
+    return;
+  RefPtr<Uint8Array> dstPixels =
+      Uint8Array::create(dstBuffer, 0, dstBuffer->byteLength());
+  image->imageForCurrentFrame()->readPixels(info, dstPixels->data(),
+                                            info.minRowBytes(), 0, 0);
+
+  GLuint textureId = 0u;
+  gl->GenTextures(1, &textureId);
+  gl->BindTexture(GL_TEXTURE_2D, textureId);
+  GLenum format =
+      (kN32_SkColorType == kRGBA_8888_SkColorType) ? GL_RGBA : GL_BGRA_EXT;
+  gl->TexImage2D(GL_TEXTURE_2D, 0, format, m_width, m_height, 0, format,
+                 GL_UNSIGNED_BYTE, 0);
+  gl->TexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+  // The pixel data will be uploaded to GPU memory, we have to keep the GPU
+  // memory alive until browser ReturnResources, so here we put textureId for
+  // that piece of GPU memory into a hashmap.
+  m_cachedTextureIds.add(m_nextResourceId, textureId);
+  gl->TexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, m_width, m_height, format,
+                    GL_UNSIGNED_BYTE, dstPixels->data());
+
+  gpu::Mailbox mailbox;
+  gl->GenMailboxCHROMIUM(mailbox.name);
+  gl->ProduceTextureCHROMIUM(GL_TEXTURE_2D, mailbox.name);
+
+  const GLuint64 fenceSync = gl->InsertFenceSyncCHROMIUM();
+  gl->ShallowFlushCHROMIUM();
+  gpu::SyncToken syncToken;
+  gl->GenSyncTokenCHROMIUM(fenceSync, syncToken.GetData());
+
+  resource.mailbox_holder =
+      gpu::MailboxHolder(mailbox, syncToken, GL_TEXTURE_2D);
+  resource.read_lock_fences_enabled = false;
+  resource.is_software = false;
+}
+
+// Case 3: both canvas and compositor are gpu accelerated.
+void OffscreenCanvasFrameDispatcherImpl::setTransferableResourceCase3(
+    cc::TransferableResource& resource,
+    RefPtr<StaticBitmapImage> image) {
+  image->ensureMailbox();
+  resource.mailbox_holder = gpu::MailboxHolder(
+      image->getMailbox(), image->getSyncToken(), GL_TEXTURE_2D);
+  resource.read_lock_fences_enabled = false;
+  resource.is_software = false;
+
+  // Hold ref to |image|, to keep it alive until the browser ReturnResources.
+  // It guarantees that the resource is not re-used or deleted.
+  m_cachedImages.add(m_nextResourceId, std::move(image));
+}
+
 void OffscreenCanvasFrameDispatcherImpl::dispatchFrame(
     RefPtr<StaticBitmapImage> image) {
   if (!image)
     return;
   if (!verifyImageSize(image->imageForCurrentFrame()))
     return;
   cc::CompositorFrame frame;
   frame.metadata.device_scale_factor = 1.0f;
   frame.delegated_frame_data.reset(new cc::DelegatedFrameData);
 
   const gfx::Rect bounds(m_width, m_height);
   const cc::RenderPassId renderPassId(1, 1);
   std::unique_ptr<cc::RenderPass> pass = cc::RenderPass::Create();
   pass->SetAll(renderPassId, bounds, bounds, gfx::Transform(), false);
 
   cc::SharedQuadState* sqs = pass->CreateAndAppendSharedQuadState();
   sqs->SetAll(gfx::Transform(), bounds.size(), bounds, bounds, false, 1.f,
               SkXfermode::kSrcOver_Mode, 0);
 
   cc::TransferableResource resource;
   resource.id = m_nextResourceId;
   resource.format = cc::ResourceFormat::RGBA_8888;
   // TODO(crbug.com/645590): filter should respect the image-rendering CSS property of associated canvas element.
   resource.filter = GL_LINEAR;
   resource.size = gfx::Size(m_width, m_height);
-  if (image->isTextureBacked()) {
-    image->ensureMailbox();
-    resource.mailbox_holder = gpu::MailboxHolder(
-        image->getMailbox(), image->getSyncToken(), GL_TEXTURE_2D);
-    resource.read_lock_fences_enabled = false;
-    resource.is_software = false;
-
-    // Hold ref to |image|, to keep it alive until the browser ReturnResources.
-    // It guarantees that the resource is not re-used or deleted.
-    m_cachedImages.add(getNextResourceIdAndIncrement(), std::move(image));
-  } else {
-    std::unique_ptr<cc::SharedBitmap> bitmap =
-        Platform::current()->allocateSharedBitmap(IntSize(m_width, m_height));
-    if (!bitmap)
-      return;
-    unsigned char* pixels = bitmap->pixels();
-    DCHECK(pixels);
-    SkImageInfo imageInfo = SkImageInfo::Make(
-        m_width, m_height, kN32_SkColorType,
-        image->isPremultiplied() ? kPremul_SkAlphaType : kUnpremul_SkAlphaType);
-    // TODO(xlai): Optimize to avoid copying pixels. See crbug.com/651456.
-    image->imageForCurrentFrame()->readPixels(imageInfo, pixels,
-                                              imageInfo.minRowBytes(), 0, 0);
-    resource.mailbox_holder.mailbox = bitmap->id();
-    resource.is_software = true;
-
-    // Hold ref to |bitmap|, to keep it alive until the browser ReturnResources.
-    // It guarantees that the shared bitmap is not re-used or deleted.
-    m_sharedBitmaps.add(getNextResourceIdAndIncrement(), std::move(bitmap));
-  }
   // TODO(crbug.com/646022): making this overlay-able.
   resource.is_overlay_candidate = false;
 
+  if (!image->isTextureBacked() &&
+      !RuntimeEnabledFeatures::gpuCompositingEnabled())
+    setTransferableResourceCase1(resource, image);
+  else if (!image->isTextureBacked() &&
+           RuntimeEnabledFeatures::gpuCompositingEnabled())
+    setTransferableResourceCase2(resource, image);
+  else
+    setTransferableResourceCase3(resource, image);
+
+  m_nextResourceId++;
   frame.delegated_frame_data->resource_list.push_back(std::move(resource));
 
   cc::TextureDrawQuad* quad =
       pass->CreateAndAppendDrawQuad<cc::TextureDrawQuad>();
   gfx::Size rectSize(m_width, m_height);
 
   const bool needsBlending = true;
   // TOOD(crbug.com/645993): this should be inherited from WebGL context's creation settings.
   const bool premultipliedAlpha = true;
   const gfx::PointF uvTopLeft(0.f, 0.f);
@@ skipping 10 matching lines @@
   frame.delegated_frame_data->render_pass_list.push_back(std::move(pass));
 
   m_sink->SubmitCompositorFrame(std::move(frame), base::Closure());
 }
 
 void OffscreenCanvasFrameDispatcherImpl::ReturnResources(
     Vector<cc::mojom::blink::ReturnedResourcePtr> resources) {
   for (const auto& resource : resources) {
     m_cachedImages.remove(resource->id);
     m_sharedBitmaps.remove(resource->id);
+    m_cachedTextureIds.remove(resource->id);
   }
 }
 
 bool OffscreenCanvasFrameDispatcherImpl::verifyImageSize(
     const sk_sp<SkImage>& image) {
   if (image && image->width() == m_width && image->height() == m_height)
     return true;
   return false;
 }
 
 }  // namespace blink