cc: Move FallbackFence implementation from GLRenderer to ResourceProvider.

cc/resources/resource_provider.cc

 // Copyright 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 "cc/resources/resource_provider.h"
 
 #include <algorithm>
 #include <limits>
 
 #include "base/containers/hash_tables.h"
@@ skipping 1112 matching lines @@
         skia::AdoptRef(gr_context->wrapBackendTexture(desc));
     SkSurface::TextRenderMode text_render_mode =
         use_distance_field_text ? SkSurface::kDistanceField_TextRenderMode
                                 : SkSurface::kStandard_TextRenderMode;
     resource_->sk_surface = skia::AdoptRef(SkSurface::NewRenderTargetDirect(
         gr_texture->asRenderTarget(), text_render_mode));
   }
   return resource_->sk_surface.get();
 }
 
+ResourceProvider::SynchronousFence::SynchronousFence(
+    gpu::gles2::GLES2Interface* gl)
+    : gl_(gl), has_synchronized_(true) {
+}
+
+ResourceProvider::SynchronousFence::~SynchronousFence() {
+}
+
+void ResourceProvider::SynchronousFence::Set() {
+  has_synchronized_ = false;
+}
+
+bool ResourceProvider::SynchronousFence::HasPassed() {
+  if (!has_synchronized_) {
+    has_synchronized_ = true;
+    Synchronize();
+  }
+  return true;
+}
+
+void ResourceProvider::SynchronousFence::Wait() {
+  HasPassed();
+}
+
+void ResourceProvider::SynchronousFence::Synchronize() {
+  TRACE_EVENT0("cc", "ResourceProvider::SynchronousFence::Synchronize");
+  gl_->Finish();
+}
+
 ResourceProvider::ResourceProvider(
     OutputSurface* output_surface,
     SharedBitmapManager* shared_bitmap_manager,
     gpu::GpuMemoryBufferManager* gpu_memory_buffer_manager,
     BlockingTaskRunner* blocking_main_thread_task_runner,
     int highp_threshold_min,
     bool use_rgba_4444_texture_format,
     size_t id_allocation_chunk_size)
     : output_surface_(output_surface),
       shared_bitmap_manager_(shared_bitmap_manager),
@@ skipping 873 matching lines @@
   DCHECK_EQ(source_resource->type, dest_resource->type);
   DCHECK_EQ(source_resource->format, dest_resource->format);
   DCHECK(source_resource->size == dest_resource->size);
 
   GLES2Interface* gl = ContextGL();
   DCHECK(gl);
   if (source_resource->image_id && source_resource->dirty_image) {
     gl->BindTexture(source_resource->target, source_resource->gl_id);
     BindImageForSampling(source_resource);
   }
-  DCHECK(use_sync_query_) << "CHROMIUM_sync_query extension missing";
-  if (!source_resource->gl_read_lock_query_id)
-    gl->GenQueriesEXT(1, &source_resource->gl_read_lock_query_id);
-  gl->BeginQueryEXT(GL_COMMANDS_COMPLETED_CHROMIUM,
-                    source_resource->gl_read_lock_query_id);
+  if (use_sync_query_) {
+    if (!source_resource->gl_read_lock_query_id)
+      gl->GenQueriesEXT(1, &source_resource->gl_read_lock_query_id);
+    gl->BeginQueryEXT(GL_COMMANDS_COMPLETED_CHROMIUM,
+                      source_resource->gl_read_lock_query_id);
+  }
   DCHECK(!dest_resource->image_id);
   dest_resource->allocated = true;
   gl->CopyTextureCHROMIUM(dest_resource->target,
                           source_resource->gl_id,
                           dest_resource->gl_id,
                           0,
                           GLInternalFormat(dest_resource->format),
                           GLDataType(dest_resource->format));
-  // End query and create a read lock fence that will prevent access to
-  // source resource until CopyTextureCHROMIUM command has completed.
-  gl->EndQueryEXT(GL_COMMANDS_COMPLETED_CHROMIUM);
-  source_resource->read_lock_fence = make_scoped_refptr(
-      new QueryFence(gl, source_resource->gl_read_lock_query_id));
+  if (source_resource->gl_read_lock_query_id) {
+    // End query and create a read lock fence that will prevent access to
+    // source resource until CopyTextureCHROMIUM command has completed.
+    gl->EndQueryEXT(GL_COMMANDS_COMPLETED_CHROMIUM);
+    source_resource->read_lock_fence = make_scoped_refptr(
+        new QueryFence(gl, source_resource->gl_read_lock_query_id));
+  } else {
+    // Create a SynchronousFence when CHROMIUM_sync_query extension is missing.
+    // Try to use one synchronous fence for as many CopyResource operations as
+    // possible as that reduce the number of times we have to synchronize with
+    // the GL.
+    if (!synchronous_fence_.get() || synchronous_fence_->has_synchronized())
+      synchronous_fence_ = make_scoped_refptr(new SynchronousFence(gl));
+    source_resource->read_lock_fence = synchronous_fence_;
+    source_resource->read_lock_fence->Set();
+  }
 }
 
 void ResourceProvider::WaitSyncPointIfNeeded(ResourceId id) {
   Resource* resource = GetResource(id);
   DCHECK_EQ(resource->exported_count, 0);
   DCHECK(resource->allocated);
   if (resource->type != GLTexture || resource->gl_id)
     return;
   if (!resource->mailbox.sync_point())
     return;
@@ skipping 23 matching lines @@
   ContextProvider* context_provider = output_surface_->context_provider();
   return context_provider ? context_provider->ContextGL() : NULL;
 }
 
 class GrContext* ResourceProvider::GrContext() const {
   ContextProvider* context_provider = output_surface_->context_provider();
   return context_provider ? context_provider->GrContext() : NULL;
 }
 
 }  // namespace cc