cc: Return resources to child compositor via a Callback.

cc/resources/resource_provider.h

 // 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.
 
 #ifndef CC_RESOURCES_RESOURCE_PROVIDER_H_
 #define CC_RESOURCES_RESOURCE_PROVIDER_H_
 
 #include <deque>
 #include <set>
 #include <string>
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/callback.h"
 #include "base/containers/hash_tables.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/threading/thread_checker.h"
 #include "cc/base/cc_export.h"
 #include "cc/output/context_provider.h"
 #include "cc/output/output_surface.h"
 #include "cc/resources/release_callback.h"
+#include "cc/resources/return_callback.h"
 #include "cc/resources/single_release_callback.h"
 #include "cc/resources/texture_mailbox.h"
 #include "cc/resources/transferable_resource.h"
 #include "third_party/khronos/GLES2/gl2.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 #include "third_party/skia/include/core/SkCanvas.h"
 #include "ui/gfx/size.h"
 
 namespace WebKit { class WebGraphicsContext3D; }
 
@@ skipping 101 matching lines @@
 
   // Finish all context operations, causing any pending callbacks to be
   // scheduled.
   void Finish();
 
   // Only flush the command buffer if supported.
   // Returns true if the shallow flush occurred, false otherwise.
   bool ShallowFlushIfSupported();
 
   // Creates accounting for a child. Returns a child ID.
-  int CreateChild();
+  int CreateChild(const ReturnCallback& return_callback);
 
   // Destroys accounting for the child, deleting all accounted resources.
   void DestroyChild(int child);
 
   // Gets the child->parent resource ID map.
   const ResourceIdMap& GetChildToParentMap(int child) const;
 
   // Prepares resources to be transfered to the parent, moving them to
   // mailboxes and serializing meta-data into TransferableResources.
   // Resources are not removed from the ResourceProvider, but are marked as
   // "in use".
   void PrepareSendToParent(const ResourceIdArray& resources,
                            TransferableResourceArray* transferable_resources);
 
-  // Prepares resources to be transfered back to the child, moving them to
-  // mailboxes and serializing meta-data into TransferableResources.
-  // Resources are removed from the ResourceProvider. Note: the resource IDs
-  // passed are in the parent namespace and will be translated to the child
-  // namespace when returned.
-  void PrepareSendReturnsToChild(int child,
-                                 const ResourceIdArray& resources,
-                                 ReturnedResourceArray* returned_resources);
-
   // Receives resources from a child, moving them from mailboxes. Resource IDs
   // passed are in the child namespace, and will be translated to the parent
   // namespace, added to the child->parent map.
+  // This adds the resources to the working set in the ResourceProvider without
+  // declaring which resources are in use. Use DeclareUsedResourcesFromChild
+  // after calling this method to do that. All calls to ReceiveFromChild should
+  // be followed by a DeclareUsedResourcesFromChild.
   // NOTE: if the sync_point is set on any TransferableResource, this will
   // wait on it.
   void ReceiveFromChild(
       int child, const TransferableResourceArray& transferable_resources);
 
+  // Once a set of resources have been received, they may or may not be used.
+  // This declares what set of resources are currently in use from the child,
+  // releasing any other resources back to the child.
+  void DeclareUsedResourcesFromChild(
+      int child,
+      const ResourceIdArray& resources_from_child);
+
   // Receives resources from the parent, moving them from mailboxes. Resource
   // IDs passed are in the child namespace.
   // NOTE: if the sync_point is set on any TransferableResource, this will
   // wait on it.
   void ReceiveReturnsFromParent(
       const ReturnedResourceArray& transferable_resources);
 
   // The following lock classes are part of the ResourceProvider API and are
   // needed to read and write the resource contents. The user must ensure
   // that they only use GL locks on GL resources, etc, and this is enforced
@@ skipping 160 matching lines @@
              GLenum filter,
              GLenum texture_pool,
              GLint wrap_mode,
              TextureUsageHint hint);
     Resource(uint8_t* pixels,
              gfx::Size size,
              GLenum format,
              GLenum filter,
              GLint wrap_mode);
 
+    int child_id;
     unsigned gl_id;
     // Pixel buffer used for set pixels without unnecessary copying.
     unsigned gl_pixel_buffer_id;
     // Query used to determine when asynchronous set pixels complete.
     unsigned gl_upload_query_id;
     TextureMailbox mailbox;
     ReleaseCallback release_callback;
     uint8_t* pixels;
     uint8_t* pixel_buffer;
     int lock_for_read_count;
@@ skipping 19 matching lines @@
     TextureUsageHint hint;
     ResourceType type;
   };
   typedef base::hash_map<ResourceId, Resource> ResourceMap;
   struct Child {
     Child();
     ~Child();
 
     ResourceIdMap child_to_parent_map;
     ResourceIdMap parent_to_child_map;
+    ReturnCallback return_callback;
+    ResourceIdSet in_use_resources;
   };
   typedef base::hash_map<int, Child> ChildMap;
 
   bool ReadLockFenceHasPassed(Resource* resource) {
     return !resource->read_lock_fence.get() ||
            resource->read_lock_fence->HasPassed();
   }
 
   explicit ResourceProvider(OutputSurface* output_surface,
                             int highp_threshold_min);
 
   void CleanUpGLIfNeeded();
 
   Resource* GetResource(ResourceId id);
   const Resource* LockForRead(ResourceId id);
   void UnlockForRead(ResourceId id);
   const Resource* LockForWrite(ResourceId id);
   void UnlockForWrite(ResourceId id);
   static void PopulateSkBitmapWithResource(SkBitmap* sk_bitmap,
                                            const Resource* resource);
 
   void TransferResource(WebKit::WebGraphicsContext3D* context,
                         ResourceId id,
                         TransferableResource* resource);
   enum DeleteStyle {
     Normal,
     ForShutdown,
   };
   void DeleteResourceInternal(ResourceMap::iterator it, DeleteStyle style);
+  void DeleteAndReturnUnusedResourcesToChild(Child* child_info,
+                                             DeleteStyle style,
+                                             const ResourceIdArray& unused);
   void LazyCreate(Resource* resource);
   void LazyAllocate(Resource* resource);
 
   // Binds the given GL resource to a texture target for sampling using the
   // specified filter for both minification and magnification. The resource
   // must be locked for reading.
   void BindForSampling(ResourceProvider::ResourceId resource_id,
                        GLenum target,
                        GLenum unit,
                        GLenum filter);
@@ skipping 23 matching lines @@
   base::ThreadChecker thread_checker_;
 
   scoped_refptr<Fence> current_read_lock_fence_;
 
   DISALLOW_COPY_AND_ASSIGN(ResourceProvider);
 };
 
 }  // namespace cc
 
 #endif  // CC_RESOURCES_RESOURCE_PROVIDER_H_