Make FencedAlloctor fail on size = 0.

gpu/command_buffer/client/fenced_allocator_test.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.
 
 // This file contains the tests for the FencedAllocator class.
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/message_loop.h"
 #include "gpu/command_buffer/client/cmd_buffer_helper.h"
@@ skipping 108 matching lines @@
   EXPECT_TRUE(allocator_->InUse());
   EXPECT_NE(FencedAllocator::kInvalidOffset, offset);
   EXPECT_GE(kBufferSize, offset+kSize);
   EXPECT_TRUE(allocator_->CheckConsistency());
 
   allocator_->Free(offset);
   EXPECT_FALSE(allocator_->InUse());
   EXPECT_TRUE(allocator_->CheckConsistency());
 }
 
+TEST_F(FencedAllocatorTest, TestAllocZero) {
+  allocator_->CheckConsistency();
+  EXPECT_FALSE(allocator_->InUse());
+
+  // Checks we can alloc size 0.
+  FencedAllocator::Offset offset = allocator_->Alloc(0);
+  EXPECT_FALSE(allocator_->InUse());
+  EXPECT_NE(FencedAllocator::kInvalidOffset, offset);
+  EXPECT_TRUE(allocator_->CheckConsistency());
+
+  // Checks 2 allocations of size 0 are not the same offset.
+  FencedAllocator::Offset offset2 = allocator_->Alloc(0);
+  EXPECT_FALSE(allocator_->InUse());
+  EXPECT_NE(FencedAllocator::kInvalidOffset, offset2);
+  EXPECT_NE(offset, offset2);
+  EXPECT_TRUE(allocator_->CheckConsistency());
+
+  // Allocates all the memory.
+  unsigned int size = allocator_->GetLargestFreeSize();
+  FencedAllocator::Offset offset3 = allocator_->Alloc(size);
+  EXPECT_TRUE(allocator_->InUse());
+  EXPECT_NE(FencedAllocator::kInvalidOffset, offset3);
+
+  // Checks there's no memory left
+  size = allocator_->GetLargestFreeSize();
+  EXPECT_EQ(0u, size);
+
+  // Checks allocations of size 0 still succeed.
+  FencedAllocator::Offset offset4 = allocator_->Alloc(0);
+  EXPECT_NE(FencedAllocator::kInvalidOffset, offset3);
+  EXPECT_NE(offset, offset4);
+  EXPECT_NE(offset2, offset4);
+  EXPECT_TRUE(allocator_->CheckConsistency());
+
+  allocator_->Free(offset);
+  EXPECT_TRUE(allocator_->InUse());
+  EXPECT_TRUE(allocator_->CheckConsistency());
+  allocator_->Free(offset2);
+  EXPECT_TRUE(allocator_->InUse());
+  EXPECT_TRUE(allocator_->CheckConsistency());
+  allocator_->Free(offset3);
+  EXPECT_FALSE(allocator_->InUse());
+  EXPECT_TRUE(allocator_->CheckConsistency());
+  allocator_->Free(offset4);
+  EXPECT_FALSE(allocator_->InUse());
+  EXPECT_TRUE(allocator_->CheckConsistency());
+}
+
 // Checks out-of-memory condition.
 TEST_F(FencedAllocatorTest, TestOutOfMemory) {
   EXPECT_TRUE(allocator_->CheckConsistency());
 
   const unsigned int kSize = 16;
   const unsigned int kAllocCount = kBufferSize / kSize;
   CHECK(kAllocCount * kSize == kBufferSize);
 
   // Allocate several buffers to fill in the memory.
   FencedAllocator::Offset offsets[kAllocCount];
@@ skipping 300 matching lines @@
   EXPECT_GE(buffer_.get() + kBufferSize,
             reinterpret_cast<char *>(pointer_uint + kSize));
 
   // Check that it did allocate kSize * sizeof(unsigned int). We can't tell
   // directly, except from the remaining size.
   EXPECT_EQ(kBufferSize - kSize * sizeof(*pointer_uint),
             allocator_->GetLargestFreeSize());
   allocator_->Free(pointer_uint);
 }
 
+TEST_F(FencedAllocatorWrapperTest, TestAllocZero) {
+  allocator_->CheckConsistency();
+
+  void* ptr = allocator_->Alloc(0);
+  EXPECT_TRUE(ptr != NULL);
+  EXPECT_TRUE(allocator_->CheckConsistency());
+
+  void* ptr2 = allocator_->Alloc(0);
+  EXPECT_TRUE(ptr2 != NULL);
+  EXPECT_NE(ptr2, ptr);
+  EXPECT_TRUE(allocator_->CheckConsistency());
+
+  allocator_->Free(ptr);
+  EXPECT_TRUE(allocator_->CheckConsistency());
+  allocator_->Free(ptr2);
+  EXPECT_TRUE(allocator_->CheckConsistency());
+}
+
 // Checks out-of-memory condition.
 TEST_F(FencedAllocatorWrapperTest, TestOutOfMemory) {
   allocator_->CheckConsistency();
 
   const unsigned int kSize = 16;
   const unsigned int kAllocCount = kBufferSize / kSize;
   CHECK(kAllocCount * kSize == kBufferSize);
 
   // Allocate several buffers to fill in the memory.
   void *pointers[kAllocCount];
@@ skipping 67 matching lines @@
   EXPECT_LE(token, GetToken());
 
   // Free up everything.
   for (unsigned int i = 0; i < kAllocCount; ++i) {
     allocator_->Free(pointers[i]);
     EXPECT_TRUE(allocator_->CheckConsistency());
   }
 }
 
 }  // namespace gpu