libs/ui/include/ui/BufferHubDefs.h - platform/frameworks/native - Git at Google

 /*
  * Copyright (C) 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.
  */

 #ifndef ANDROID_BUFFER_HUB_DEFS_H_
 #define ANDROID_BUFFER_HUB_DEFS_H_

 #include <atomic>

 #pragma clang diagnostic push
 #pragma clang diagnostic ignored "-Wpacked"
 // TODO(b/118893702): remove dependency once DvrNativeBufferMetadata moved out of libdvr
 #include <dvr/dvr_api.h>
 #pragma clang diagnostic pop

 namespace android {

 namespace BufferHubDefs {

 // Single buffer clients (up to 16) ownership signal.
 // 32-bit atomic unsigned int.
 // Each client takes 2 bits. The first bit locates in the first 16 bits of
 // bufferState; the second bit locates in the last 16 bits of bufferState.
 // Client states:
 // Gained state 11. Exclusive write state.
 // Posted state 10.
 // Acquired state 01. Shared read state.
 // Released state 00.
 //
 //  MSB                        LSB
 //   |                          |
 //   v                          v
 // [C15|...|C1|C0|C15| ... |C1|C0]

 // Maximum number of clients a buffer can have.
 static constexpr int kMaxNumberOfClients = 16;

 // Definition of bit masks.
 //  MSB                            LSB
 //   | kHighBitsMask | kLowbitsMask |
 //   v               v              v
 // [b31|   ...   |b16|b15|   ...  |b0]

 // The location of lower 16 bits in the 32-bit buffer state.
 static constexpr uint32_t kLowbitsMask = (1U << kMaxNumberOfClients) - 1U;

 // The location of higher 16 bits in the 32-bit buffer state.
 static constexpr uint32_t kHighBitsMask = ~kLowbitsMask;

 // The client bit mask of the first client.
 static constexpr uint32_t kFirstClientBitMask = (1U << kMaxNumberOfClients) + 1U;

 // Returns true if any of the client is in gained state.
 static inline bool isAnyClientGained(uint32_t state) {
     uint32_t highBits = state >> kMaxNumberOfClients;
     uint32_t lowBits = state & kLowbitsMask;
     return highBits == lowBits && lowBits != 0U;
 }

 // Returns true if the input client is in gained state.
 static inline bool isClientGained(uint32_t state, uint32_t client_bit_mask) {
     return state == client_bit_mask;
 }

 // Returns true if any of the client is in posted state.
 static inline bool isAnyClientPosted(uint32_t state) {
     uint32_t highBits = state >> kMaxNumberOfClients;
     uint32_t lowBits = state & kLowbitsMask;
     uint32_t postedOrAcquired = highBits ^ lowBits;
     return postedOrAcquired & highBits;
 }

 // Returns true if the input client is in posted state.
 static inline bool isClientPosted(uint32_t state, uint32_t client_bit_mask) {
     uint32_t clientBits = state & client_bit_mask;
     if (clientBits == 0U) return false;
     uint32_t lowBits = clientBits & kLowbitsMask;
     return lowBits == 0U;
 }

 // Return true if any of the client is in acquired state.
 static inline bool isAnyClientAcquired(uint32_t state) {
     uint32_t highBits = state >> kMaxNumberOfClients;
     uint32_t lowBits = state & kLowbitsMask;
     uint32_t postedOrAcquired = highBits ^ lowBits;
     return postedOrAcquired & lowBits;
 }

 // Return true if the input client is in acquired state.
 static inline bool isClientAcquired(uint32_t state, uint32_t client_bit_mask) {
     uint32_t clientBits = state & client_bit_mask;
     if (clientBits == 0U) return false;
     uint32_t highBits = clientBits & kHighBitsMask;
     return highBits == 0U;
 }

 // Returns true if the input client is in released state.
 static inline bool isClientReleased(uint32_t state, uint32_t client_bit_mask) {
     return (state & client_bit_mask) == 0U;
 }

 // Returns the next available buffer client's client_state_masks.
 // @params union_bits. Union of all existing clients' client_state_masks.
 static inline uint32_t findNextAvailableClientStateMask(uint32_t union_bits) {
     uint32_t lowUnion = union_bits & kLowbitsMask;
     if (lowUnion == kLowbitsMask) return 0U;
     uint32_t incremented = lowUnion + 1U;
     uint32_t difference = incremented ^ lowUnion;
     uint32_t newLowBit = (difference + 1U) >> 1;
     return newLowBit + (newLowBit << kMaxNumberOfClients);
 }

 struct __attribute__((aligned(8))) MetadataHeader {
     // Internal data format, which can be updated as long as the size, padding and field alignment
     // of the struct is consistent within the same ABI. As this part is subject for future updates,
     // it's not stable cross Android version, so don't have it visible from outside of the Android
     // platform (include Apps and vendor HAL).

     // Every client takes up one bit from the higher 32 bits and one bit from the lower 32 bits in
     // bufferState.
     std::atomic<uint32_t> bufferState;

     // Every client takes up one bit in fenceState. Only the lower 32 bits are valid. The upper 32
     // bits are there for easier manipulation, but the value should be ignored.
     std::atomic<uint32_t> fenceState;

     // Every client takes up one bit from the higher 32 bits and one bit from the lower 32 bits in
     // activeClientsBitMask.
     std::atomic<uint32_t> activeClientsBitMask;

     // Explicit padding 4 bytes.
     uint32_t padding;

     // The index of the buffer queue where the buffer belongs to.
     uint64_t queueIndex;

     // Public data format, which should be updated with caution. See more details in dvr_api.h
     DvrNativeBufferMetadata metadata;
 };

 static_assert(sizeof(MetadataHeader) == 128, "Unexpected MetadataHeader size");
 static constexpr size_t kMetadataHeaderSize = sizeof(MetadataHeader);

 /**
  * android.frameworks.bufferhub@1.0::BufferTraits.bufferInfo is an opaque handle. See
  * https://cs.corp.google.com/android/frameworks/hardware/interfaces/bufferhub/1.0/types.hal for
  * more details about android.frameworks.bufferhub@1.0::BufferTraits.
  *
  * This definition could be changed, but implementation of BufferHubService::buildBufferInfo
  * (frameworks/native/services/bufferhub), VtsHalBufferHubV1_0TargetTest
  * (frameworks/hardware/interfaces/bufferhub) and BufferHubBuffer::readBufferTraits (libui) will
  * also need to be updated.
  *
  * It's definition should follow the following format:
  * {
  *   NumFds = 2,
  *   NumInts = 3,
  *   data[0] = Ashmem fd for BufferHubMetadata,
  *   data[1] = event fd,
  *   data[2] = buffer id,
  *   data[3] = client state bit mask,
  *   data[4] = user metadata size,
  * }
  */
 static constexpr int kBufferInfoNumFds = 2;
 static constexpr int kBufferInfoNumInts = 3;

 } // namespace BufferHubDefs

 } // namespace android

 #endif // ANDROID_BUFFER_HUB_DEFS_H_
	/*
	* Copyright (C) 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.
	*/

	#ifndef ANDROID_BUFFER_HUB_DEFS_H_
	#define ANDROID_BUFFER_HUB_DEFS_H_

	#include <atomic>

	#pragma clang diagnostic push
	#pragma clang diagnostic ignored "-Wpacked"
	// TODO(b/118893702): remove dependency once DvrNativeBufferMetadata moved out of libdvr
	#include <dvr/dvr_api.h>
	#pragma clang diagnostic pop

	namespace android {

	namespace BufferHubDefs {

	// Single buffer clients (up to 16) ownership signal.
	// 32-bit atomic unsigned int.
	// Each client takes 2 bits. The first bit locates in the first 16 bits of
	// bufferState; the second bit locates in the last 16 bits of bufferState.
	// Client states:
	// Gained state 11. Exclusive write state.
	// Posted state 10.
	// Acquired state 01. Shared read state.
	// Released state 00.
	//
	// MSB LSB
	// \| \|
	// v v
	// [C15\|...\|C1\|C0\|C15\| ... \|C1\|C0]

	// Maximum number of clients a buffer can have.
	static constexpr int kMaxNumberOfClients = 16;

	// Definition of bit masks.
	// MSB LSB
	// \| kHighBitsMask \| kLowbitsMask \|
	// v v v
	// [b31\| ... \|b16\|b15\| ... \|b0]

	// The location of lower 16 bits in the 32-bit buffer state.
	static constexpr uint32_t kLowbitsMask = (1U << kMaxNumberOfClients) - 1U;

	// The location of higher 16 bits in the 32-bit buffer state.
	static constexpr uint32_t kHighBitsMask = ~kLowbitsMask;

	// The client bit mask of the first client.
	static constexpr uint32_t kFirstClientBitMask = (1U << kMaxNumberOfClients) + 1U;

	// Returns true if any of the client is in gained state.
	static inline bool isAnyClientGained(uint32_t state) {
	uint32_t highBits = state >> kMaxNumberOfClients;
	uint32_t lowBits = state & kLowbitsMask;
	return highBits == lowBits && lowBits != 0U;
	}

	// Returns true if the input client is in gained state.
	static inline bool isClientGained(uint32_t state, uint32_t client_bit_mask) {
	return state == client_bit_mask;
	}

	// Returns true if any of the client is in posted state.
	static inline bool isAnyClientPosted(uint32_t state) {
	uint32_t highBits = state >> kMaxNumberOfClients;
	uint32_t lowBits = state & kLowbitsMask;
	uint32_t postedOrAcquired = highBits ^ lowBits;
	return postedOrAcquired & highBits;
	}

	// Returns true if the input client is in posted state.
	static inline bool isClientPosted(uint32_t state, uint32_t client_bit_mask) {
	uint32_t clientBits = state & client_bit_mask;
	if (clientBits == 0U) return false;
	uint32_t lowBits = clientBits & kLowbitsMask;
	return lowBits == 0U;
	}

	// Return true if any of the client is in acquired state.
	static inline bool isAnyClientAcquired(uint32_t state) {
	uint32_t highBits = state >> kMaxNumberOfClients;
	uint32_t lowBits = state & kLowbitsMask;
	uint32_t postedOrAcquired = highBits ^ lowBits;
	return postedOrAcquired & lowBits;
	}

	// Return true if the input client is in acquired state.
	static inline bool isClientAcquired(uint32_t state, uint32_t client_bit_mask) {
	uint32_t clientBits = state & client_bit_mask;
	if (clientBits == 0U) return false;
	uint32_t highBits = clientBits & kHighBitsMask;
	return highBits == 0U;
	}

	// Returns true if the input client is in released state.
	static inline bool isClientReleased(uint32_t state, uint32_t client_bit_mask) {
	return (state & client_bit_mask) == 0U;
	}

	// Returns the next available buffer client's client_state_masks.
	// @params union_bits. Union of all existing clients' client_state_masks.
	static inline uint32_t findNextAvailableClientStateMask(uint32_t union_bits) {
	uint32_t lowUnion = union_bits & kLowbitsMask;
	if (lowUnion == kLowbitsMask) return 0U;
	uint32_t incremented = lowUnion + 1U;
	uint32_t difference = incremented ^ lowUnion;
	uint32_t newLowBit = (difference + 1U) >> 1;
	return newLowBit + (newLowBit << kMaxNumberOfClients);
	}

	struct __attribute__((aligned(8))) MetadataHeader {
	// Internal data format, which can be updated as long as the size, padding and field alignment
	// of the struct is consistent within the same ABI. As this part is subject for future updates,
	// it's not stable cross Android version, so don't have it visible from outside of the Android
	// platform (include Apps and vendor HAL).

	// Every client takes up one bit from the higher 32 bits and one bit from the lower 32 bits in
	// bufferState.
	std::atomic<uint32_t> bufferState;

	// Every client takes up one bit in fenceState. Only the lower 32 bits are valid. The upper 32
	// bits are there for easier manipulation, but the value should be ignored.
	std::atomic<uint32_t> fenceState;

	// Every client takes up one bit from the higher 32 bits and one bit from the lower 32 bits in
	// activeClientsBitMask.
	std::atomic<uint32_t> activeClientsBitMask;

	// Explicit padding 4 bytes.
	uint32_t padding;

	// The index of the buffer queue where the buffer belongs to.
	uint64_t queueIndex;

	// Public data format, which should be updated with caution. See more details in dvr_api.h
	DvrNativeBufferMetadata metadata;
	};

	static_assert(sizeof(MetadataHeader) == 128, "Unexpected MetadataHeader size");
	static constexpr size_t kMetadataHeaderSize = sizeof(MetadataHeader);

	/**
	* android.frameworks.bufferhub@1.0::BufferTraits.bufferInfo is an opaque handle. See
	* https://cs.corp.google.com/android/frameworks/hardware/interfaces/bufferhub/1.0/types.hal for
	* more details about android.frameworks.bufferhub@1.0::BufferTraits.
	*
	* This definition could be changed, but implementation of BufferHubService::buildBufferInfo
	* (frameworks/native/services/bufferhub), VtsHalBufferHubV1_0TargetTest
	* (frameworks/hardware/interfaces/bufferhub) and BufferHubBuffer::readBufferTraits (libui) will
	* also need to be updated.
	*
	* It's definition should follow the following format:
	* {
	* NumFds = 2,
	* NumInts = 3,
	* data[0] = Ashmem fd for BufferHubMetadata,
	* data[1] = event fd,
	* data[2] = buffer id,
	* data[3] = client state bit mask,
	* data[4] = user metadata size,
	* }
	*/
	static constexpr int kBufferInfoNumFds = 2;
	static constexpr int kBufferInfoNumInts = 3;

	} // namespace BufferHubDefs

	} // namespace android

	#endif // ANDROID_BUFFER_HUB_DEFS_H_