Enforce a memory limit on MappedMemoryManager

gpu/command_buffer/client/mapped_memory_unittest.cc

 // 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.
 
 #include "gpu/command_buffer/client/mapped_memory.h"
 
 #include "base/bind.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/message_loop/message_loop.h"
 #include "gpu/command_buffer/client/cmd_buffer_helper.h"
@@ skipping 288 matching lines @@
   ASSERT_TRUE(mem2);
   ASSERT_TRUE(mem3);
   EXPECT_NE(-1, id1);
   EXPECT_EQ(id1, id2);
   EXPECT_NE(id2, id3);
   EXPECT_EQ(0u, offset1);
   EXPECT_EQ(kSize, offset2);
   EXPECT_EQ(0u, offset3);
 }
 
+TEST_F(MappedMemoryManagerTest, MemoryLimit) {
+  const unsigned int kSize = 1024;
+  // Reset the manager with a memory limit.
+  manager_.reset(new MappedMemoryManager(helper_.get(), 2 * kSize));
+  const unsigned int kChunkSize = 2 * 1024;
+  manager_->set_chunk_size_multiple(2 * kSize);
+
+  // Allocate half a chunk worth of memory.
+  int32 id1 = -1;
+  unsigned int offset1 = 0xFFFFFFFFU;
+  void* mem1 = manager_->Alloc(kSize, &id1, &offset1);
+  ASSERT_TRUE(mem1);
+  EXPECT_NE(-1, id1);
+  EXPECT_EQ(0u, offset1);
+
+  // Allocate half a chunk worth of memory again.
+  // The same chunk will be used.
+  int32 id2 = -1;
+  unsigned int offset2 = 0xFFFFFFFFU;
+  void* mem2 = manager_->Alloc(kSize, &id2, &offset2);
+  ASSERT_TRUE(mem2);
+  EXPECT_NE(-1, id2);
+  EXPECT_EQ(kSize, offset2);
+
+  // Allocate half a chunk worth of memory.
+  int32 id3 = -1;
+  unsigned int offset3 = 0xFFFFFFFFU;
+  void* mem3 = manager_->Alloc(kSize, &id3, &offset3);
+  ASSERT_TRUE(mem3);
+  EXPECT_NE(-1, id3);
+  EXPECT_EQ(0u, offset3);
+
+  // Expect two chunks to be allocated, even though
+  // the memory limit was set to be one chunk.
+  // This proves the memory limit is a soft limit, rather
+  // than a hard one.
+  EXPECT_EQ(2 * kChunkSize, manager_->allocated_memory());
+}
+
+TEST_F(MappedMemoryManagerTest, MemoryLimitWithReuse) {
+  const unsigned int kSize = 1024;
+  // Reset the manager with a memory limit.
+  manager_.reset(new MappedMemoryManager(helper_.get(), 2 * kSize));
+  const unsigned int kChunkSize = 2 * 1024;
+  manager_->set_chunk_size_multiple(kChunkSize);
+
+  // Allocate half a chunk worth of memory.
+  int32 id1 = -1;
+  unsigned int offset1 = 0xFFFFFFFFU;
+  void* mem1 = manager_->Alloc(kSize, &id1, &offset1);
+  ASSERT_TRUE(mem1);
+  EXPECT_NE(-1, id1);
+  EXPECT_EQ(0u, offset1);
+
+  // Allocate half a chunk worth of memory again.
+  // The same chunk will be used.
+  int32 id2 = -1;
+  unsigned int offset2 = 0xFFFFFFFFU;
+  void* mem2 = manager_->Alloc(kSize, &id2, &offset2);
+  ASSERT_TRUE(mem2);
+  EXPECT_NE(-1, id2);
+  EXPECT_EQ(kSize, offset2);
+
+  // Free one successful allocation, pending fence.
+  int32 token = helper_.get()->InsertToken();
+  manager_->FreePendingToken(mem2, token);
+
+  // The way we hooked up the helper and engine, it won't process commands
+  // until it has to wait for something. Which means the token shouldn't have
+  // passed yet at this point.
+  EXPECT_GT(token, GetToken());
+
+  // Since we didn't call helper_.finish() the token did not pass.
+  // We won't be able to claim the free memory without waiting and
+  // as we've already met the memory limit we'll have to wait
+  // on the token.
+  int32 id3 = -1;
+  unsigned int offset3 = 0xFFFFFFFFU;
+  void* mem3 = manager_->Alloc(kSize, &id3, &offset3);
+  ASSERT_TRUE(mem3);
+  EXPECT_NE(-1, id3);
+  // It will reuse the space from the second allocation just freed.
+  EXPECT_EQ(kSize, offset3);
+
+  // Expect one chunk to be allocated
+  EXPECT_EQ(1 * kChunkSize, manager_->allocated_memory());
+}
+
 }  // namespace gpu