gpu: Reuse transfer buffers more aggresively

gpu/command_buffer/client/buffer_tracker.h

Index: gpu/command_buffer/client/buffer_tracker.h
diff --git a/gpu/command_buffer/client/buffer_tracker.h b/gpu/command_buffer/client/buffer_tracker.h
index 3e50364317d234bc9d7ed336c81de4fdbc26d5a4..8fadca918bc95330608a58f5a74fecc81fb1297a 100644
--- a/gpu/command_buffer/client/buffer_tracker.h
+++ b/gpu/command_buffer/client/buffer_tracker.h
@@ -35,7 +35,9 @@ class GLES2_IMPL_EXPORT BufferTracker {
           shm_offset_(shm_offset),
           address_(address),
           mapped_(false),
-          transfer_ready_token_(0) {
+          transfer_ready_token_(0),
+          unused_token_(0),
+          async_query_id_(0) {
     }
 
     GLenum id() const {
@@ -74,6 +76,30 @@ class GLES2_IMPL_EXPORT BufferTracker {
       return transfer_ready_token_;
     }
 
+    void set_used(bool used) {
+      used_ = used;
+    }
+
+    bool used() const {
+      return used_;
+    }
+
+    void set_unused_token(int token) {
+      unused_token_ = token;
+    }
+
+    int unused_token() const {
+      return unused_token_;
+    }
+
+    void set_async_query_id(GLuint async_query_id) {
+      async_query_id_ = async_query_id;
+    }
+
+    GLuint async_query_id() const {
+      return async_query_id_;
+    }
+
    private:
     friend class BufferTracker;
     friend class BufferTrackerTest;
@@ -83,8 +109,11 @@ class GLES2_IMPL_EXPORT BufferTracker {
     int32 shm_id_;
     uint32 shm_offset_;
     void* address_;
-    bool mapped_;
+    bool mapped_ : 1;
+    bool used_ : 1;
     int32 transfer_ready_token_;
+    int32 unused_token_;

[epennerAtGoogle, 2014/01/07 00:47:59]

Does this mean: "The buffer is unused after this token passes"? I mildly prefer
"last_usage_token" or something like that. Similarly, I mildly prefer
"last_async_query_id".

[reveman, 2014/01/07 06:32:06]

+1

[jadahl, 2014/01/07 10:52:03]

last_usage_token np. last_async_query_id might be confusing since its the
*active* async query.

+    GLuint async_query_id_;
   };
 
   BufferTracker(MappedMemoryManager* manager);
@@ -93,10 +122,12 @@ class GLES2_IMPL_EXPORT BufferTracker {
   Buffer* CreateBuffer(GLuint id, GLsizeiptr size);
   Buffer* GetBuffer(GLuint id);
   void RemoveBuffer(GLuint id);
+  void UnmanageBuffer(GLuint id);
 
   // Frees the block of memory associated with buffer, pending the passage
   // of a token.
-  void FreePendingToken(Buffer*, int32 token);
+  void FreePendingToken(Buffer* buffer, int32 token);
+  void Free(Buffer* buffer);
 
  private:
   typedef base::hash_map<GLuint, Buffer*> BufferMap;