Make FencedAlloctor fail on size = 0.

gpu/command_buffer/client/fenced_allocator_test.cc

Index: gpu/command_buffer/client/fenced_allocator_test.cc
diff --git a/gpu/command_buffer/client/fenced_allocator_test.cc b/gpu/command_buffer/client/fenced_allocator_test.cc
index 381237bbe48fd4672a1d5c95cab5b7ea20f2cfba..abf8a7f32abadf40763416dd41607c7fa62e5e86 100644
--- a/gpu/command_buffer/client/fenced_allocator_test.cc
+++ b/gpu/command_buffer/client/fenced_allocator_test.cc
@@ -126,6 +126,54 @@ TEST_F(FencedAllocatorTest, TestBasic) {
   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());
@@ -446,6 +494,24 @@ TEST_F(FencedAllocatorWrapperTest, TestBasic) {
   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();