Enforce a memory limit on MappedMemoryManager

gpu/command_buffer/client/mapped_memory.h

 // Copyright (c) 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 GPU_COMMAND_BUFFER_CLIENT_MAPPED_MEMORY_H_
 #define GPU_COMMAND_BUFFER_CLIENT_MAPPED_MEMORY_H_
 
 #include "base/memory/scoped_vector.h"
 #include "gpu/command_buffer/client/fenced_allocator.h"
 #include "gpu/command_buffer/common/buffer.h"
@@ skipping 61 matching lines @@
   // Frees a block of memory, pending the passage of a token. That memory won't
   // be re-allocated until the token has passed through the command stream.
   //
   // Parameters:
   //   pointer: the pointer to the memory block to free.
   //   token: the token value to wait for before re-using the memory.
   void FreePendingToken(void* pointer, unsigned int token) {
     allocator_.FreePendingToken(pointer, token);
   }
 
-  // Frees any blocks who's tokens have passed.
+  // Frees any blocks whose tokens have passed.
   void FreeUnused() {
     allocator_.FreeUnused();
   }
 
   // Returns true if pointer is in the range of this block.
   bool IsInChunk(void* pointer) const {
     return pointer >= shm_.ptr &&
            pointer < reinterpret_cast<const int8*>(shm_.ptr) + shm_.size;
   }
 
-  // Returns true of any memory in this chuck is in use.
+  // Returns true of any memory in this chunk is in use.
   bool InUse() {
     return allocator_.InUse();
   }
 
+  size_t bytes_in_use() const {
+    return allocator_.bytes_in_use();
+  }
+
  private:
   int32 shm_id_;
   gpu::Buffer shm_;
   FencedAllocatorWrapper allocator_;
 
   DISALLOW_COPY_AND_ASSIGN(MemoryChunk);
 };
 
-// Manages MemoryChucks.
+// Manages MemoryChunks.
 class GPU_EXPORT MappedMemoryManager {
  public:
-  explicit MappedMemoryManager(CommandBufferHelper* helper);
+  enum MemoryLimit {
+    kNoLimit = 0,
+  };
+
+  // |unused_memory_reclaim_limit|: When exceeded this causes pending memory
+  // to be reclaimed before allocating more memory.
+  MappedMemoryManager(CommandBufferHelper* helper,
+                      size_t unused_memory_reclaim_limit);
 
   ~MappedMemoryManager();
 
   unsigned int chunk_size_multiple() const {
     return chunk_size_multiple_;
   }
 
   void set_chunk_size_multiple(unsigned int multiple) {
     chunk_size_multiple_ = multiple;
   }
@@ skipping 19 matching lines @@
   //
   // Parameters:
   //   pointer: the pointer to the memory block to free.
   //   token: the token value to wait for before re-using the memory.
   void FreePendingToken(void* pointer, int32 token);
 
   // Free Any Shared memory that is not in use.
   void FreeUnused();
 
   // Used for testing
-  size_t num_chunks() {
+  size_t num_chunks() const {
     return chunks_.size();
   }
 
+  // Used for testing
+  size_t allocated_memory() const {
+    return allocated_memory_;
+  }
+
  private:
   typedef ScopedVector<MemoryChunk> MemoryChunkVector;
 
   // size a chunk is rounded up to.
   unsigned int chunk_size_multiple_;
   CommandBufferHelper* helper_;
   MemoryChunkVector chunks_;
+  size_t allocated_memory_;
+  size_t max_free_bytes_;
 
   DISALLOW_COPY_AND_ASSIGN(MappedMemoryManager);
 };
 
 }  // namespace gpu
 
 #endif  // GPU_COMMAND_BUFFER_CLIENT_MAPPED_MEMORY_H_