cc: Partial tile update for one-copy raster.

cc/resources/resource_pool.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_POOL_H_
 #define CC_RESOURCES_RESOURCE_POOL_H_
 
 #include <list>
 
 #include "base/memory/scoped_ptr.h"
 #include "cc/base/cc_export.h"
 #include "cc/output/renderer.h"
 #include "cc/resources/resource.h"
 #include "cc/resources/resource_format.h"
 
 namespace cc {
 class ScopedResource;
 
 class CC_EXPORT ResourcePool {
  public:
   static scoped_ptr<ResourcePool> Create(ResourceProvider* resource_provider,
                                          GLenum target) {
     return make_scoped_ptr(new ResourcePool(resource_provider, target));
   }
 
   virtual ~ResourcePool();
 
   scoped_ptr<ScopedResource> AcquireResource(const gfx::Size& size,
                                              ResourceFormat format);
-  void ReleaseResource(scoped_ptr<ScopedResource>);
+  scoped_ptr<ScopedResource> TryAcquireOldResource(const gfx::Size& size,
+                                                   ResourceFormat format,

[reveman, 2015/05/14 23:52:20]

Why are we providing |size| and |format| when asking for a specific id?

[danakj, 2015/05/14 23:56:34]

In case the new tile has a different size/format than the previous tile did.
This makes things more robust I think?

+                                                   uint64 id);
+  scoped_ptr<ScopedResource> TryAcquireOldBusyResource(const gfx::Size& size,
+                                                       ResourceFormat format,

[reveman, 2015/05/14 23:52:20]

ditto

+                                                       uint64 id);
+  void ReleaseResource(scoped_ptr<ScopedResource> resource, uint64_t id);
 
   void SetResourceUsageLimits(size_t max_memory_usage_bytes,
                               size_t max_unused_memory_usage_bytes,
                               size_t max_resource_count);
 
   void ReduceResourceUsage();
   // This might block if |wait_if_needed| is true and one of the currently
   // busy resources has a read lock fence that needs to be waited upon before
   // it can be locked for write again.
   void CheckBusyResources(bool wait_if_needed);
 
   size_t total_memory_usage_bytes() const { return memory_usage_bytes_; }
   size_t acquired_memory_usage_bytes() const {
     return memory_usage_bytes_ - unused_memory_usage_bytes_;
   }
   size_t total_resource_count() const { return resource_count_; }
   size_t acquired_resource_count() const {
     return resource_count_ - unused_resources_.size();
   }
   size_t busy_resource_count() const { return busy_resources_.size(); }
 
  protected:
   ResourcePool(ResourceProvider* resource_provider, GLenum target);
 
   bool ResourceUsageTooHigh();
 
  private:
-  void DidFinishUsingResource(ScopedResource* resource);
+  void DidFinishUsingResource(ScopedResource* resource, uint64_t id);
 
   ResourceProvider* resource_provider_;
   const GLenum target_;
   size_t max_memory_usage_bytes_;
   size_t max_unused_memory_usage_bytes_;
   size_t max_resource_count_;
   size_t memory_usage_bytes_;
   size_t unused_memory_usage_bytes_;
   size_t resource_count_;
 
-  typedef std::list<ScopedResource*> ResourceList;
+  struct PoolResource {
+    PoolResource(ScopedResource* resource, uint64_t id)
+        : resource(resource), id(id) {}
+    ScopedResource* resource;
+    uint64_t id;
+  };
+  typedef std::list<PoolResource> ResourceList;
   ResourceList unused_resources_;
   ResourceList busy_resources_;
 
   DISALLOW_COPY_AND_ASSIGN(ResourcePool);
 };
 
 }  // namespace cc
 
 #endif  // CC_RESOURCES_RESOURCE_POOL_H_