gpu: Reuse transfer buffers more aggresively

gpu/command_buffer/client/fenced_allocator.h

Index: gpu/command_buffer/client/fenced_allocator.h
diff --git a/gpu/command_buffer/client/fenced_allocator.h b/gpu/command_buffer/client/fenced_allocator.h
index bb5c55170ab25e2766a4804c762a51ee00e8c2f3..f2d39879dab5b165ee02c397720a84287e52c6c1 100644
--- a/gpu/command_buffer/client/fenced_allocator.h
+++ b/gpu/command_buffer/client/fenced_allocator.h
@@ -35,6 +35,7 @@ class GPU_EXPORT FencedAllocator {
   // Creates a FencedAllocator. Note that the size of the buffer is passed, but
   // not its base address: everything is handled as offsets into the buffer.
   FencedAllocator(unsigned int size,
+                  bool aggressive_reuse,

[epennerAtGoogle, 2013/12/18 19:21:15]

Rather than a separate allocator, do you think it would be possible to flag
deletions for immediate reuse (ie. skip free-pending state)?  This is partially
a question for reveman/sievers (as to how best this could be communicated from
the client).

                   CommandBufferHelper *helper);
 
   ~FencedAllocator();
@@ -87,6 +88,8 @@ class GPU_EXPORT FencedAllocator {
   size_t bytes_in_use() const { return bytes_in_use_; }
 
  private:
+  Offset AggressiveAlloc(unsigned int size);
+
   // Status of a block of memory, for book-keeping.
   enum State {
     IN_USE,
@@ -137,6 +140,7 @@ class GPU_EXPORT FencedAllocator {
 
   CommandBufferHelper *helper_;
   Container blocks_;
+  bool aggressive_reuse_;
   size_t bytes_in_use_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(FencedAllocator);
@@ -147,9 +151,10 @@ class GPU_EXPORT FencedAllocator {
 class FencedAllocatorWrapper {
  public:
   FencedAllocatorWrapper(unsigned int size,
+                         bool aggressive_reuse,
                          CommandBufferHelper* helper,
                          void* base)
-      : allocator_(size, helper),
+      : allocator_(size, aggressive_reuse, helper),
         base_(base) { }
 
   // Allocates a block of memory. If the buffer is out of directly available