libs/ui/tests/BufferHubBuffer_test.cpp - android_frameworks_native - Gitiles

 /*
  * Copyright 2018 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 #define LOG_TAG "BufferHubBufferTest"

 #include <android/frameworks/bufferhub/1.0/IBufferClient.h>
 #include <android/frameworks/bufferhub/1.0/IBufferHub.h>
 #include <android/hardware_buffer.h>
 #include <cutils/native_handle.h>
 #include <gtest/gtest.h>
 #include <hidl/ServiceManagement.h>
 #include <hwbinder/IPCThreadState.h>
 #include <ui/BufferHubBuffer.h>

 namespace android {

 namespace {

 const int kWidth = 640;
 const int kHeight = 480;
 const int kLayerCount = 1;
 const int kFormat = HAL_PIXEL_FORMAT_RGBA_8888;
 const int kUsage = 0;
 const size_t kUserMetadataSize = 0;

 using BufferHubDefs::AnyClientAcquired;
 using BufferHubDefs::AnyClientGained;
 using BufferHubDefs::AnyClientPosted;
 using BufferHubDefs::IsBufferReleased;
 using BufferHubDefs::IsClientAcquired;
 using BufferHubDefs::IsClientGained;
 using BufferHubDefs::IsClientPosted;
 using BufferHubDefs::IsClientReleased;
 using BufferHubDefs::kFirstClientBitMask;
 using BufferHubDefs::kMetadataHeaderSize;
 using frameworks::bufferhub::V1_0::BufferHubStatus;
 using frameworks::bufferhub::V1_0::IBufferClient;
 using frameworks::bufferhub::V1_0::IBufferHub;
 using hardware::hidl_handle;
 using hardware::graphics::common::V1_2::HardwareBufferDescription;
 using hidl::base::V1_0::IBase;
 using pdx::LocalChannelHandle;

 class BufferHubBufferTest : public ::testing::Test {
 protected:
     void SetUp() override { android::hardware::ProcessState::self()->startThreadPool(); }
 };

 class BufferHubBufferStateTransitionTest : public BufferHubBufferTest {
 protected:
     void SetUp() override {
         BufferHubBufferTest::SetUp();
         CreateTwoClientsOfABuffer();
     }

     std::unique_ptr<BufferHubBuffer> b1;
     uint64_t b1ClientMask = 0U;
     std::unique_ptr<BufferHubBuffer> b2;
     uint64_t b2ClientMask = 0U;

 private:
     // Creates b1 and b2 as the clients of the same buffer for testing.
     void CreateTwoClientsOfABuffer();
 };

 void BufferHubBufferStateTransitionTest::CreateTwoClientsOfABuffer() {
     b1 = BufferHubBuffer::Create(kWidth, kHeight, kLayerCount, kFormat, kUsage, kUserMetadataSize);
     b1ClientMask = b1->client_state_mask();
     ASSERT_NE(b1ClientMask, 0U);
     auto statusOrHandle = b1->Duplicate();
     ASSERT_TRUE(statusOrHandle);
     LocalChannelHandle h2 = statusOrHandle.take();
     b2 = BufferHubBuffer::Import(std::move(h2));
     b2ClientMask = b2->client_state_mask();
     ASSERT_NE(b2ClientMask, 0U);
     ASSERT_NE(b2ClientMask, b1ClientMask);
 }

 TEST_F(BufferHubBufferTest, CreateBufferHubBufferFails) {
     // Buffer Creation will fail: BLOB format requires height to be 1.
     auto b1 = BufferHubBuffer::Create(kWidth, /*height=*/2, kLayerCount,
                                       /*format=*/HAL_PIXEL_FORMAT_BLOB, kUsage, kUserMetadataSize);

     EXPECT_FALSE(b1->IsConnected());
     EXPECT_FALSE(b1->IsValid());

     // Buffer Creation will fail: user metadata size too large.
     auto b2 = BufferHubBuffer::Create(kWidth, kHeight, kLayerCount, kFormat, kUsage,
                                       /*userMetadataSize=*/std::numeric_limits<size_t>::max());

     EXPECT_FALSE(b2->IsConnected());
     EXPECT_FALSE(b2->IsValid());

     // Buffer Creation will fail: user metadata size too large.
     const size_t userMetadataSize = std::numeric_limits<size_t>::max() - kMetadataHeaderSize;
     auto b3 = BufferHubBuffer::Create(kWidth, kHeight, kLayerCount, kFormat, kUsage,
                                       userMetadataSize);

     EXPECT_FALSE(b3->IsConnected());
     EXPECT_FALSE(b3->IsValid());
 }

 TEST_F(BufferHubBufferTest, CreateBufferHubBuffer) {
     auto b1 = BufferHubBuffer::Create(kWidth, kHeight, kLayerCount, kFormat, kUsage,
                                       kUserMetadataSize);
     EXPECT_TRUE(b1->IsConnected());
     EXPECT_TRUE(b1->IsValid());
     EXPECT_NE(b1->id(), 0);
 }

 TEST_F(BufferHubBufferTest, DuplicateBufferHubBuffer) {
     auto b1 = BufferHubBuffer::Create(kWidth, kHeight, kLayerCount, kFormat, kUsage,
                                       kUserMetadataSize);
     int id1 = b1->id();
     uint64_t bufferStateMask1 = b1->client_state_mask();
     EXPECT_NE(bufferStateMask1, 0U);
     EXPECT_TRUE(b1->IsValid());
     EXPECT_EQ(b1->user_metadata_size(), kUserMetadataSize);

     auto statusOrHandle = b1->Duplicate();
     EXPECT_TRUE(statusOrHandle);

     // The detached buffer should still be valid.
     EXPECT_TRUE(b1->IsConnected());
     EXPECT_TRUE(b1->IsValid());

     // Gets the channel handle for the duplicated buffer.
     LocalChannelHandle h2 = statusOrHandle.take();
     EXPECT_TRUE(h2.valid());

     std::unique_ptr<BufferHubBuffer> b2 = BufferHubBuffer::Import(std::move(h2));
     EXPECT_FALSE(h2.valid());
     ASSERT_TRUE(b2 != nullptr);
     EXPECT_TRUE(b2->IsValid());
     EXPECT_EQ(b2->user_metadata_size(), kUserMetadataSize);

     int id2 = b2->id();
     uint64_t bufferStateMask2 = b2->client_state_mask();
     EXPECT_NE(bufferStateMask2, 0U);

     // These two buffer instances are based on the same physical buffer under the
     // hood, so they should share the same id.
     EXPECT_EQ(id1, id2);
     // We use client_state_mask() to tell those two instances apart.
     EXPECT_NE(bufferStateMask1, bufferStateMask2);

     // Both buffer instances should be in released state currently.
     EXPECT_TRUE(IsBufferReleased(b1->buffer_state()));
     EXPECT_TRUE(IsBufferReleased(b2->buffer_state()));

     // TODO(b/112338294): rewrite test after migration
     return;
 }

 TEST_F(BufferHubBufferStateTransitionTest, GainBuffer_fromReleasedState) {
     ASSERT_TRUE(IsBufferReleased(b1->buffer_state()));

     // Successful gaining the buffer should change the buffer state bit of b1 to
     // gained state, other client state bits to released state.
     EXPECT_EQ(b1->Gain(), 0);
     EXPECT_TRUE(IsClientGained(b1->buffer_state(), b1ClientMask));
 }

 TEST_F(BufferHubBufferStateTransitionTest, GainBuffer_fromGainedState) {
     ASSERT_EQ(b1->Gain(), 0);
     auto current_buffer_state = b1->buffer_state();
     ASSERT_TRUE(IsClientGained(current_buffer_state, b1ClientMask));

     // Gaining from gained state by the same client should not return error.
     EXPECT_EQ(b1->Gain(), 0);

     // Gaining from gained state by another client should return error.
     EXPECT_EQ(b2->Gain(), -EBUSY);
 }

 TEST_F(BufferHubBufferStateTransitionTest, GainBuffer_fromAcquiredState) {
     ASSERT_EQ(b1->Gain(), 0);
     ASSERT_EQ(b1->Post(), 0);
     ASSERT_EQ(b2->Acquire(), 0);
     ASSERT_TRUE(AnyClientAcquired(b1->buffer_state()));

     // Gaining from acquired state should fail.
     EXPECT_EQ(b1->Gain(), -EBUSY);
     EXPECT_EQ(b2->Gain(), -EBUSY);
 }

 TEST_F(BufferHubBufferStateTransitionTest, GainBuffer_fromOtherClientInPostedState) {
     ASSERT_EQ(b1->Gain(), 0);
     ASSERT_EQ(b1->Post(), 0);
     ASSERT_TRUE(AnyClientPosted(b1->buffer_state()));

     // Gaining a buffer who has other posted client should succeed.
     EXPECT_EQ(b1->Gain(), 0);
 }

 TEST_F(BufferHubBufferStateTransitionTest, GainBuffer_fromSelfInPostedState) {
     ASSERT_EQ(b1->Gain(), 0);
     ASSERT_EQ(b1->Post(), 0);
     ASSERT_TRUE(AnyClientPosted(b1->buffer_state()));

     // A posted client should be able to gain the buffer when there is no other clients in
     // acquired state.
     EXPECT_EQ(b2->Gain(), 0);
 }

 TEST_F(BufferHubBufferStateTransitionTest, PostBuffer_fromOtherInGainedState) {
     ASSERT_EQ(b1->Gain(), 0);
     ASSERT_TRUE(IsClientGained(b1->buffer_state(), b1ClientMask));

     EXPECT_EQ(b2->Post(), -EBUSY);
 }

 TEST_F(BufferHubBufferStateTransitionTest, PostBuffer_fromSelfInGainedState) {
     ASSERT_EQ(b1->Gain(), 0);
     ASSERT_TRUE(IsClientGained(b1->buffer_state(), b1ClientMask));

     EXPECT_EQ(b1->Post(), 0);
     auto current_buffer_state = b1->buffer_state();
     EXPECT_TRUE(IsClientReleased(current_buffer_state, b1ClientMask));
     EXPECT_TRUE(IsClientPosted(current_buffer_state, b2ClientMask));
 }

 TEST_F(BufferHubBufferStateTransitionTest, PostBuffer_fromPostedState) {
     ASSERT_EQ(b1->Gain(), 0);
     ASSERT_EQ(b1->Post(), 0);
     ASSERT_TRUE(AnyClientPosted(b1->buffer_state()));

     // Post from posted state should fail.
     EXPECT_EQ(b1->Post(), -EBUSY);
     EXPECT_EQ(b2->Post(), -EBUSY);
 }

 TEST_F(BufferHubBufferStateTransitionTest, PostBuffer_fromAcquiredState) {
     ASSERT_EQ(b1->Gain(), 0);
     ASSERT_EQ(b1->Post(), 0);
     ASSERT_EQ(b2->Acquire(), 0);
     ASSERT_TRUE(AnyClientAcquired(b1->buffer_state()));

     // Posting from acquired state should fail.
     EXPECT_EQ(b1->Post(), -EBUSY);
     EXPECT_EQ(b2->Post(), -EBUSY);
 }

 TEST_F(BufferHubBufferStateTransitionTest, PostBuffer_fromReleasedState) {
     ASSERT_TRUE(IsBufferReleased(b1->buffer_state()));

     // Posting from released state should fail.
     EXPECT_EQ(b1->Post(), -EBUSY);
     EXPECT_EQ(b2->Post(), -EBUSY);
 }

 TEST_F(BufferHubBufferStateTransitionTest, AcquireBuffer_fromSelfInPostedState) {
     ASSERT_EQ(b1->Gain(), 0);
     ASSERT_EQ(b1->Post(), 0);
     ASSERT_TRUE(IsClientPosted(b1->buffer_state(), b2ClientMask));

     // Acquire from posted state should pass.
     EXPECT_EQ(b2->Acquire(), 0);
 }

 TEST_F(BufferHubBufferStateTransitionTest, AcquireBuffer_fromOtherInPostedState) {
     ASSERT_EQ(b1->Gain(), 0);
     ASSERT_EQ(b1->Post(), 0);
     ASSERT_TRUE(IsClientPosted(b1->buffer_state(), b2ClientMask));

     // Acquire from released state should fail, although there are other clients
     // in posted state.
     EXPECT_EQ(b1->Acquire(), -EBUSY);
 }

 TEST_F(BufferHubBufferStateTransitionTest, AcquireBuffer_fromSelfInAcquiredState) {
     ASSERT_EQ(b1->Gain(), 0);
     ASSERT_EQ(b1->Post(), 0);
     ASSERT_EQ(b2->Acquire(), 0);
     auto current_buffer_state = b1->buffer_state();
     ASSERT_TRUE(IsClientAcquired(current_buffer_state, b2ClientMask));

     // Acquiring from acquired state by the same client should not error out.
     EXPECT_EQ(b2->Acquire(), 0);
 }

 TEST_F(BufferHubBufferStateTransitionTest, AcquireBuffer_fromReleasedState) {
     ASSERT_TRUE(IsBufferReleased(b1->buffer_state()));

     // Acquiring form released state should fail.
     EXPECT_EQ(b1->Acquire(), -EBUSY);
     EXPECT_EQ(b2->Acquire(), -EBUSY);
 }

 TEST_F(BufferHubBufferStateTransitionTest, AcquireBuffer_fromGainedState) {
     ASSERT_EQ(b1->Gain(), 0);
     ASSERT_TRUE(AnyClientGained(b1->buffer_state()));

     // Acquiring from gained state should fail.
     EXPECT_EQ(b1->Acquire(), -EBUSY);
     EXPECT_EQ(b2->Acquire(), -EBUSY);
 }

 TEST_F(BufferHubBufferStateTransitionTest, ReleaseBuffer_fromSelfInReleasedState) {
     ASSERT_TRUE(IsBufferReleased(b1->buffer_state()));

     EXPECT_EQ(b1->Release(), 0);
 }

 TEST_F(BufferHubBufferStateTransitionTest, ReleaseBuffer_fromSelfInGainedState) {
     ASSERT_TRUE(IsBufferReleased(b1->buffer_state()));
     ASSERT_EQ(b1->Gain(), 0);
     ASSERT_TRUE(AnyClientGained(b1->buffer_state()));

     EXPECT_EQ(b1->Release(), 0);
 }

 TEST_F(BufferHubBufferStateTransitionTest, ReleaseBuffer_fromSelfInPostedState) {
     ASSERT_EQ(b1->Gain(), 0);
     ASSERT_EQ(b1->Post(), 0);
     ASSERT_TRUE(AnyClientPosted(b1->buffer_state()));

     EXPECT_EQ(b2->Release(), 0);
 }

 TEST_F(BufferHubBufferStateTransitionTest, ReleaseBuffer_fromSelfInAcquiredState) {
     ASSERT_EQ(b1->Gain(), 0);
     ASSERT_EQ(b1->Post(), 0);
     ASSERT_EQ(b2->Acquire(), 0);
     ASSERT_TRUE(AnyClientAcquired(b1->buffer_state()));

     EXPECT_EQ(b2->Release(), 0);
 }

 } // namespace
 } // namespace android
	/*
	* Copyright 2018 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	#define LOG_TAG "BufferHubBufferTest"

	#include <android/frameworks/bufferhub/1.0/IBufferClient.h>
	#include <android/frameworks/bufferhub/1.0/IBufferHub.h>
	#include <android/hardware_buffer.h>
	#include <cutils/native_handle.h>
	#include <gtest/gtest.h>
	#include <hidl/ServiceManagement.h>
	#include <hwbinder/IPCThreadState.h>
	#include <ui/BufferHubBuffer.h>

	namespace android {

	namespace {

	const int kWidth = 640;
	const int kHeight = 480;
	const int kLayerCount = 1;
	const int kFormat = HAL_PIXEL_FORMAT_RGBA_8888;
	const int kUsage = 0;
	const size_t kUserMetadataSize = 0;

	using BufferHubDefs::AnyClientAcquired;
	using BufferHubDefs::AnyClientGained;
	using BufferHubDefs::AnyClientPosted;
	using BufferHubDefs::IsBufferReleased;
	using BufferHubDefs::IsClientAcquired;
	using BufferHubDefs::IsClientGained;
	using BufferHubDefs::IsClientPosted;
	using BufferHubDefs::IsClientReleased;
	using BufferHubDefs::kFirstClientBitMask;
	using BufferHubDefs::kMetadataHeaderSize;
	using frameworks::bufferhub::V1_0::BufferHubStatus;
	using frameworks::bufferhub::V1_0::IBufferClient;
	using frameworks::bufferhub::V1_0::IBufferHub;
	using hardware::hidl_handle;
	using hardware::graphics::common::V1_2::HardwareBufferDescription;
	using hidl::base::V1_0::IBase;
	using pdx::LocalChannelHandle;

	class BufferHubBufferTest : public ::testing::Test {
	protected:
	void SetUp() override { android::hardware::ProcessState::self()->startThreadPool(); }
	};

	class BufferHubBufferStateTransitionTest : public BufferHubBufferTest {
	protected:
	void SetUp() override {
	BufferHubBufferTest::SetUp();
	CreateTwoClientsOfABuffer();
	}

	std::unique_ptr<BufferHubBuffer> b1;
	uint64_t b1ClientMask = 0U;
	std::unique_ptr<BufferHubBuffer> b2;
	uint64_t b2ClientMask = 0U;

	private:
	// Creates b1 and b2 as the clients of the same buffer for testing.
	void CreateTwoClientsOfABuffer();
	};

	void BufferHubBufferStateTransitionTest::CreateTwoClientsOfABuffer() {
	b1 = BufferHubBuffer::Create(kWidth, kHeight, kLayerCount, kFormat, kUsage, kUserMetadataSize);
	b1ClientMask = b1->client_state_mask();
	ASSERT_NE(b1ClientMask, 0U);
	auto statusOrHandle = b1->Duplicate();
	ASSERT_TRUE(statusOrHandle);
	LocalChannelHandle h2 = statusOrHandle.take();
	b2 = BufferHubBuffer::Import(std::move(h2));
	b2ClientMask = b2->client_state_mask();
	ASSERT_NE(b2ClientMask, 0U);
	ASSERT_NE(b2ClientMask, b1ClientMask);
	}

	TEST_F(BufferHubBufferTest, CreateBufferHubBufferFails) {
	// Buffer Creation will fail: BLOB format requires height to be 1.
	auto b1 = BufferHubBuffer::Create(kWidth, /height=/2, kLayerCount,
	/format=/HAL_PIXEL_FORMAT_BLOB, kUsage, kUserMetadataSize);

	EXPECT_FALSE(b1->IsConnected());
	EXPECT_FALSE(b1->IsValid());

	// Buffer Creation will fail: user metadata size too large.
	auto b2 = BufferHubBuffer::Create(kWidth, kHeight, kLayerCount, kFormat, kUsage,
	/userMetadataSize=/std::numeric_limits<size_t>::max());

	EXPECT_FALSE(b2->IsConnected());
	EXPECT_FALSE(b2->IsValid());

	// Buffer Creation will fail: user metadata size too large.
	const size_t userMetadataSize = std::numeric_limits<size_t>::max() - kMetadataHeaderSize;
	auto b3 = BufferHubBuffer::Create(kWidth, kHeight, kLayerCount, kFormat, kUsage,
	userMetadataSize);

	EXPECT_FALSE(b3->IsConnected());
	EXPECT_FALSE(b3->IsValid());
	}

	TEST_F(BufferHubBufferTest, CreateBufferHubBuffer) {
	auto b1 = BufferHubBuffer::Create(kWidth, kHeight, kLayerCount, kFormat, kUsage,
	kUserMetadataSize);
	EXPECT_TRUE(b1->IsConnected());
	EXPECT_TRUE(b1->IsValid());
	EXPECT_NE(b1->id(), 0);
	}

	TEST_F(BufferHubBufferTest, DuplicateBufferHubBuffer) {
	auto b1 = BufferHubBuffer::Create(kWidth, kHeight, kLayerCount, kFormat, kUsage,
	kUserMetadataSize);
	int id1 = b1->id();
	uint64_t bufferStateMask1 = b1->client_state_mask();
	EXPECT_NE(bufferStateMask1, 0U);
	EXPECT_TRUE(b1->IsValid());
	EXPECT_EQ(b1->user_metadata_size(), kUserMetadataSize);

	auto statusOrHandle = b1->Duplicate();
	EXPECT_TRUE(statusOrHandle);

	// The detached buffer should still be valid.
	EXPECT_TRUE(b1->IsConnected());
	EXPECT_TRUE(b1->IsValid());

	// Gets the channel handle for the duplicated buffer.
	LocalChannelHandle h2 = statusOrHandle.take();
	EXPECT_TRUE(h2.valid());

	std::unique_ptr<BufferHubBuffer> b2 = BufferHubBuffer::Import(std::move(h2));
	EXPECT_FALSE(h2.valid());
	ASSERT_TRUE(b2 != nullptr);
	EXPECT_TRUE(b2->IsValid());
	EXPECT_EQ(b2->user_metadata_size(), kUserMetadataSize);

	int id2 = b2->id();
	uint64_t bufferStateMask2 = b2->client_state_mask();
	EXPECT_NE(bufferStateMask2, 0U);

	// These two buffer instances are based on the same physical buffer under the
	// hood, so they should share the same id.
	EXPECT_EQ(id1, id2);
	// We use client_state_mask() to tell those two instances apart.
	EXPECT_NE(bufferStateMask1, bufferStateMask2);

	// Both buffer instances should be in released state currently.
	EXPECT_TRUE(IsBufferReleased(b1->buffer_state()));
	EXPECT_TRUE(IsBufferReleased(b2->buffer_state()));

	// TODO(b/112338294): rewrite test after migration
	return;
	}

	TEST_F(BufferHubBufferStateTransitionTest, GainBuffer_fromReleasedState) {
	ASSERT_TRUE(IsBufferReleased(b1->buffer_state()));

	// Successful gaining the buffer should change the buffer state bit of b1 to
	// gained state, other client state bits to released state.
	EXPECT_EQ(b1->Gain(), 0);
	EXPECT_TRUE(IsClientGained(b1->buffer_state(), b1ClientMask));
	}

	TEST_F(BufferHubBufferStateTransitionTest, GainBuffer_fromGainedState) {
	ASSERT_EQ(b1->Gain(), 0);
	auto current_buffer_state = b1->buffer_state();
	ASSERT_TRUE(IsClientGained(current_buffer_state, b1ClientMask));

	// Gaining from gained state by the same client should not return error.
	EXPECT_EQ(b1->Gain(), 0);

	// Gaining from gained state by another client should return error.
	EXPECT_EQ(b2->Gain(), -EBUSY);
	}

	TEST_F(BufferHubBufferStateTransitionTest, GainBuffer_fromAcquiredState) {
	ASSERT_EQ(b1->Gain(), 0);
	ASSERT_EQ(b1->Post(), 0);
	ASSERT_EQ(b2->Acquire(), 0);
	ASSERT_TRUE(AnyClientAcquired(b1->buffer_state()));

	// Gaining from acquired state should fail.
	EXPECT_EQ(b1->Gain(), -EBUSY);
	EXPECT_EQ(b2->Gain(), -EBUSY);
	}

	TEST_F(BufferHubBufferStateTransitionTest, GainBuffer_fromOtherClientInPostedState) {
	ASSERT_EQ(b1->Gain(), 0);
	ASSERT_EQ(b1->Post(), 0);
	ASSERT_TRUE(AnyClientPosted(b1->buffer_state()));

	// Gaining a buffer who has other posted client should succeed.
	EXPECT_EQ(b1->Gain(), 0);
	}

	TEST_F(BufferHubBufferStateTransitionTest, GainBuffer_fromSelfInPostedState) {
	ASSERT_EQ(b1->Gain(), 0);
	ASSERT_EQ(b1->Post(), 0);
	ASSERT_TRUE(AnyClientPosted(b1->buffer_state()));

	// A posted client should be able to gain the buffer when there is no other clients in
	// acquired state.
	EXPECT_EQ(b2->Gain(), 0);
	}

	TEST_F(BufferHubBufferStateTransitionTest, PostBuffer_fromOtherInGainedState) {
	ASSERT_EQ(b1->Gain(), 0);
	ASSERT_TRUE(IsClientGained(b1->buffer_state(), b1ClientMask));

	EXPECT_EQ(b2->Post(), -EBUSY);
	}

	TEST_F(BufferHubBufferStateTransitionTest, PostBuffer_fromSelfInGainedState) {
	ASSERT_EQ(b1->Gain(), 0);
	ASSERT_TRUE(IsClientGained(b1->buffer_state(), b1ClientMask));

	EXPECT_EQ(b1->Post(), 0);
	auto current_buffer_state = b1->buffer_state();
	EXPECT_TRUE(IsClientReleased(current_buffer_state, b1ClientMask));
	EXPECT_TRUE(IsClientPosted(current_buffer_state, b2ClientMask));
	}

	TEST_F(BufferHubBufferStateTransitionTest, PostBuffer_fromPostedState) {
	ASSERT_EQ(b1->Gain(), 0);
	ASSERT_EQ(b1->Post(), 0);
	ASSERT_TRUE(AnyClientPosted(b1->buffer_state()));

	// Post from posted state should fail.
	EXPECT_EQ(b1->Post(), -EBUSY);
	EXPECT_EQ(b2->Post(), -EBUSY);
	}

	TEST_F(BufferHubBufferStateTransitionTest, PostBuffer_fromAcquiredState) {
	ASSERT_EQ(b1->Gain(), 0);
	ASSERT_EQ(b1->Post(), 0);
	ASSERT_EQ(b2->Acquire(), 0);
	ASSERT_TRUE(AnyClientAcquired(b1->buffer_state()));

	// Posting from acquired state should fail.
	EXPECT_EQ(b1->Post(), -EBUSY);
	EXPECT_EQ(b2->Post(), -EBUSY);
	}

	TEST_F(BufferHubBufferStateTransitionTest, PostBuffer_fromReleasedState) {
	ASSERT_TRUE(IsBufferReleased(b1->buffer_state()));

	// Posting from released state should fail.
	EXPECT_EQ(b1->Post(), -EBUSY);
	EXPECT_EQ(b2->Post(), -EBUSY);
	}

	TEST_F(BufferHubBufferStateTransitionTest, AcquireBuffer_fromSelfInPostedState) {
	ASSERT_EQ(b1->Gain(), 0);
	ASSERT_EQ(b1->Post(), 0);
	ASSERT_TRUE(IsClientPosted(b1->buffer_state(), b2ClientMask));

	// Acquire from posted state should pass.
	EXPECT_EQ(b2->Acquire(), 0);
	}

	TEST_F(BufferHubBufferStateTransitionTest, AcquireBuffer_fromOtherInPostedState) {
	ASSERT_EQ(b1->Gain(), 0);
	ASSERT_EQ(b1->Post(), 0);
	ASSERT_TRUE(IsClientPosted(b1->buffer_state(), b2ClientMask));

	// Acquire from released state should fail, although there are other clients
	// in posted state.
	EXPECT_EQ(b1->Acquire(), -EBUSY);
	}

	TEST_F(BufferHubBufferStateTransitionTest, AcquireBuffer_fromSelfInAcquiredState) {
	ASSERT_EQ(b1->Gain(), 0);
	ASSERT_EQ(b1->Post(), 0);
	ASSERT_EQ(b2->Acquire(), 0);
	auto current_buffer_state = b1->buffer_state();
	ASSERT_TRUE(IsClientAcquired(current_buffer_state, b2ClientMask));

	// Acquiring from acquired state by the same client should not error out.
	EXPECT_EQ(b2->Acquire(), 0);
	}

	TEST_F(BufferHubBufferStateTransitionTest, AcquireBuffer_fromReleasedState) {
	ASSERT_TRUE(IsBufferReleased(b1->buffer_state()));

	// Acquiring form released state should fail.
	EXPECT_EQ(b1->Acquire(), -EBUSY);
	EXPECT_EQ(b2->Acquire(), -EBUSY);
	}

	TEST_F(BufferHubBufferStateTransitionTest, AcquireBuffer_fromGainedState) {
	ASSERT_EQ(b1->Gain(), 0);
	ASSERT_TRUE(AnyClientGained(b1->buffer_state()));

	// Acquiring from gained state should fail.
	EXPECT_EQ(b1->Acquire(), -EBUSY);
	EXPECT_EQ(b2->Acquire(), -EBUSY);
	}

	TEST_F(BufferHubBufferStateTransitionTest, ReleaseBuffer_fromSelfInReleasedState) {
	ASSERT_TRUE(IsBufferReleased(b1->buffer_state()));

	EXPECT_EQ(b1->Release(), 0);
	}

	TEST_F(BufferHubBufferStateTransitionTest, ReleaseBuffer_fromSelfInGainedState) {
	ASSERT_TRUE(IsBufferReleased(b1->buffer_state()));
	ASSERT_EQ(b1->Gain(), 0);
	ASSERT_TRUE(AnyClientGained(b1->buffer_state()));

	EXPECT_EQ(b1->Release(), 0);
	}

	TEST_F(BufferHubBufferStateTransitionTest, ReleaseBuffer_fromSelfInPostedState) {
	ASSERT_EQ(b1->Gain(), 0);
	ASSERT_EQ(b1->Post(), 0);
	ASSERT_TRUE(AnyClientPosted(b1->buffer_state()));

	EXPECT_EQ(b2->Release(), 0);
	}

	TEST_F(BufferHubBufferStateTransitionTest, ReleaseBuffer_fromSelfInAcquiredState) {
	ASSERT_EQ(b1->Gain(), 0);
	ASSERT_EQ(b1->Post(), 0);
	ASSERT_EQ(b2->Acquire(), 0);
	ASSERT_TRUE(AnyClientAcquired(b1->buffer_state()));

	EXPECT_EQ(b2->Release(), 0);
	}

	} // namespace
	} // namespace android