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Android开发graphics bufferqueue整体流程

　　目录

　　一、引言

　　1、bufferqueue 的四大流程；

　　2、简要介绍四大流程的调用过程；

　　本文主要讲解安卓图形绘制中的buffer queue

　　页面数据通过canvas/Open GL ES/vulkan绘制后，形成一帧buffer，交给buffer queue，buffer queue再把数据送到屏幕上显示。所以buffer queue是图形绘制中很核心的一环，它本身就是一个缓冲区池与队列相结合的数据结构。

　　Buffer queue:

　　图像缓冲区，系统中绝大部分图形数据都会缓冲于此。等待surfaceflinger组织进一步的合成和显示

　　备注：本文摘录的代码只摘录关键代码和路径，需读者自行结合阅读.由于本文的重点在bufferqueue，其它和bufferqueue相关的流程提到的时候会精简列出，作为辅助理解。

　　二、Buffer queue

　　2.1、buffer queue的创建

　　bufferquque构建

　　//BufferQueue.cpp frameworks

　　ativelibsgui

　　void BufferQueue::createBufferQueue(sp* outProducer,

　　sp* outConsumer,

　　bool consumerIsSurfaceFlinger) {

　　sp core(new BufferQueueCore());

　　sp producer(new BufferQueueProducer(core, consumerIsSurfaceFlinger));

　　sp consumer(new BufferQueueConsumer(core));

　　*outProducer = producer;

　　*outConsumer = consumer;

　　}

　　构建调用流程

　　下面堆栈表示了底层surface创建bufferqueue的一个过程

　　04-20 11:45:54.739 674 707 E createBufferQueue: #00 pc 0004ca33 /system/lib/libgui.so (android::BufferQueue::createBufferQueue(android::sp*, android::sp*, bool)+74)

　　04-20 11:45:54.739 674 707 E createBufferQueue: #01 pc 00068539 /system/lib/libsurfaceflinger.so (android::BufferQueueLayer::onFirstRef()+40)

　　04-20 11:45:54.739 674 707 E createBufferQueue: #02 pc 000d5ad1 /system/lib/libsurfaceflinger.so (android::surfaceflinger::DefaultFactory::createBufferQueueLayer(android::LayerCreationArgs const&)+52)

　　04-20 11:45:54.739 674 707 E createBufferQueue: #03 pc 000c11d5 /system/lib/libsurfaceflinger.so (android::SurfaceFlinger::createLayer(android::String8 const&, android::sp const&, unsigned int, unsigned int, int, unsigned int, android::LayerMetadata, android::sp*, android::sp*, android::sp const&, android::sp const&, unsigned int*)+1056)

　　04-20 11:45:54.739 674 707 E createBufferQueue: #04 pc 0006e197 /system/lib/libsurfaceflinger.so (android::Client::createSurface(android::String8 const&, unsigned int, unsigned int, int, unsigned int, android::sp const&, android::LayerMetadata, android::sp*, android::sp*, unsigned int*)+122)

　　04-20 11:45:54.739 674 707 E createBufferQueue: #05 pc 0007b34f /system/lib/libgui.so (int android::SafeBnInterface::MethodCaller const&, android::LayerMetadata, android::sp*, android::sp*, unsigned int*> >::callHelper, int (android::ISurfaceComposerClient::*)(android::String8 const&, unsigned int, unsigned int, int, unsigned int, android::sp const&, android::LayerMetadata, android::sp*, android::sp*, unsigned int*), std::__1::tuple, android::LayerMetadata, android::sp, android::sp, unsigned int>, 0u, 1u, 2u, 3u, 4u, 5u, 6u, 7u, 8u, 9u>(android

　　04-20 11:45:54.739 674 707 E createBufferQueue: #06 pc 00079e2f /system/lib/libgui.so (int android::SafeBnInterface::callLocal const&, android::LayerMetadata, android::sp*, android::sp*, unsigned int*)>(android::Parcel const&, android::Parcel*, int (android::ISurfaceComposerClient::*)(android::String8 const&, unsigned int, unsigned int, int, unsigned int, android::sp const&, android::LayerMetadata, android::sp*, android::sp*, unsigned int*))+158)

　　04-20 11:45:54.739 674 707 E createBufferQueue: #07 pc 00079d3f /system/lib/libgui.so (android::BnSurfaceComposerClient::onTransact(unsigned int, android::Parcel const&, android::Parcel*, unsigned int)+46)

　　BufferQueueCore:bufferqueue的实际实例，由他来衔接生产者和消费者

　　BufferQueueProducer:bufferqueue工厂模式的接口，生产者

　　BufferQueueConsumer:bufferqueue消费接口，消费者

　　BufferQueueCore 负责维护 BufferQueue 的基本数据结构，而 BufferQueueProducer 和 BufferQueueConsumer 则负责提供操作 BufferQueue 的基本接口。

　　2.2、buffer queue整体流程

　　2.2.1、流程概要

　　image.png

　　这张图片清晰的表述的buffer queue的工作方式，两大功能：生产buffer、消费buffer。

　　dequeueBuffer:向buffer queue请求一个缓冲区，并指定缓冲区的宽度、高度、像素格式和用法标志

　　queueBuffer:把缓冲区返回到队列

　　acquireBuffer:获取缓冲区内容

　　releaseBuffer:把数据返回到队列

　　这里有两次返回队列，其实都是返回buffer queue的数据结构中。简述两个流程

　　通篇文章，我们就在理解BufferQueueProducer 和 BufferQueueConsumer如何操作上面这四个流程requestBuffer

　　int Surface::dequeueBuffer(android_native_buffer_t** buffer, int* fenceFd) {

　　status_t result = mGraphicBufferProducer->dequeueBuffer(&buf, &fence, reqWidth, reqHeight,

　　reqFormat, reqUsage, &mBufferAge,

　　enableFrameTimestamps ? &frameTimestamps

　　: nullptr);

　　...

　　if ((result & IGraphicBufferProducer::BUFFER_NEEDS_REALLOCATION) || gbuf == nullptr) {

　　if (mReportRemovedBuffers && (gbuf != nullptr)) {

　　mRemovedBuffers.push_back(gbuf);

　　}

　　result = mGraphicBufferProducer->requestBuffer(buf, &gbuf);

　　requestBuffer单独提一下这个流程，当我们首次dequeueBuffer过后，surface会调用requestBuffer,requestBuffer的主要作用就是把GraphicBuffer传给应用侧，

　　这个动作只需要做一次，应用侧拿到GraphicBuffer过后就可以把共享内存mmap到应用侧的内存空间，然后才可以绘制图像。

　　2.2.2、bufferqueue被调用流程

　　本小结主要目的是，在我们认识bufferqueu的是如何工作的同时，不脱离surfaceflinger整体框架。简单提一下它是如果调用来的。以便我们更深入理解。

　　1、dequeueBuffer&&queueBuffe

　　r当app创建window的时候，会创建surface来显示。实则会创建底层的surface。底层surface创建时会hook住dequeueBuffer和queueBuffer方法。

　　surface持有mGraphicBufferProducer对象来创建bufferqueue

　　dequeueBuffer方法位置：BufferQueueProducer::dequeueBuffer

　　04-20 09:48:38.909 6053 6263 E graphic dequeueBuffer: #00 pc 0006dea5 /system/lib/libgui.so (android::BpGraphicBufferProducer::dequeueBuffer(int*, android::sp*, unsigned int, unsigned int, int, unsigned long long, unsigned long long*, android::FrameEventHistoryDelta*)+136)

　　04-20 09:48:38.909 6053 6263 E graphic dequeueBuffer: #01 pc 000842ed /system/lib/libgui.so (android::Surface::dequeueBuffer(ANativeWindowBuffer**, int*)+316)

　　04-20 09:48:38.909 6053 6263 E graphic dequeueBuffer: #02 pc 0015004b /system/lib/libhwui.so (android::uirenderer::renderthread::ReliableSurface::hook_dequeueBuffer(ANativeWindow*, int (*)(ANativeWindow*, ANativeWindowBuffer**, int*), void*, ANativeWindowBuffer**, int*)+42)

　　04-20 09:48:38.909 6053 6263 E graphic dequeueBuffer: #03 pc 00083181 /system/lib/libgui.so (android::Surface::hook_dequeueBuffer(ANativeWindow*, ANativeWindowBuffer**, int*)+60)

　　//接上面，binder调用到BufferQueueProducer

　　04-20 09:48:38.946 668 697 E dequeueBuffer: #00 pc 00052653 /system/lib/libgui.so (android::BufferQueueProducer::dequeueBuffer(int*, android::sp*, unsigned int, unsigned int, int, unsigned long long, unsigned long long*, android::FrameEventHistoryDelta*)+250)

　　04-20 09:48:38.946 668 697 E dequeueBuffer: #01 pc 0006d117 /system/lib/libgui.so (android::BnGraphicBufferProducer::onTransact(unsigned int, android::Parcel const&, android::Parcel*, unsigned int)+374)

　　queueBuffer方法位置：BufferQueueProducer::queueBuffer

　　04-20 09:48:38.987 6053 6263 E queueBuffer: #00 pc 0006e4e1 /system/lib/libgui.so (android::BpGraphicBufferProducer::queueBuffer(int, android::IGraphicBufferProducer::QueueBufferInput const&, android::IGraphicBufferProducer::QueueBufferOutput*)+128)

　　04-20 09:48:38.987 6053 6263 E queueBuffer: #01 pc 00084d83 /system/lib/libgui.so (android::Surface::queueBuffer(ANativeWindowBuffer*, int)+722)

　　04-20 09:48:38.987 6053 6263 E queueBuffer: #02 pc 00083259 /system/lib/libgui.so (android::Surface::hook_queueBuffer(ANativeWindow*, ANativeWindowBuffer*, int)+60)

　　//接上面，binder调用到BufferQueueProducer

　　04-20 09:48:39.017 668 697 E queueBuffer: #00 pc 00053877 /system/lib/libgui.so (android::BufferQueueProducer::queueBuffer(int, android::IGraphicBufferProducer::QueueBufferInput const&, android::IGraphicBufferProducer::QueueBufferOutput*)+266)

　　04-20 09:48:39.017 668 697 E queueBuffer: #01 pc 0006d345 /system/lib/libgui.so (android::BnGraphicBufferProducer::onTransact(unsigned int, android::Parcel const&, android::Parcel*, unsigned int)+932)

　　2、acquireBuffer&&releaseBuffer

　　//SurfaceFlinger.cpp

　　void SurfaceFlinger::onMessageReceived(int32_t what, nsecs_t expectedVSyncTime) {

　　ATRACE_CALL();

　　switch (what) {

　　case MessageQueue::INVALIDATE: {

　　onMessageInvalidate(expectedVSyncTime);

　　break;

　　}

　　case MessageQueue::REFRESH: {

　　onMessageRefresh();

　　break;

　　}

　　}

　　}

　　acquireBuffer方法位置：BufferQueueConsumer::acquireBuffer

　　04-19 19:33:38.926 666 666 E acquireBuffer: #00 pc 0004d34f /system/lib/libgui.so (android::BufferQueueConsumer::acquireBuffer(android::BufferItem*, long long, unsigned long long)+74)

　　04-19 19:33:38.926 666 666 E acquireBuffer: #01 pc 000645cf /system/lib/libgui.so (android::ConsumerBase::acquireBufferLocked(android::BufferItem*, long long, unsigned long long)+62)

　　04-19 19:33:38.926 666 666 E acquireBuffer: #02 pc 0007a7a1 /system/lib/libsurfaceflinger.so (android::FramebufferSurface::advanceFrame(bool)+112)

　　04-19 19:33:38.926 666 666 E acquireBuffer: #03 pc 000edf1f /system/lib/libsurfaceflinger.so (android::compositionengine::impl::RenderSurface::queueBuffer(android::base::unique_fd_impl, bool)+358)

　　04-19 19:33:38.926 666 666 E acquireBuffer: #04 pc 000e46e7 /system/lib/libsurfaceflinger.so (android::compositionengine::impl::Output::finishFrame(android::compositionengine::CompositionRefreshArgs const&)+454)

　　04-19 19:33:38.926 666 666 E acquireBuffer: #05 pc 000de3e5 /system/lib/libsurfaceflinger.so (android::compositionengine::impl::Display::finishFrame(android::compositionengine::CompositionRefreshArgs const&)+72)

　　04-19 19:33:38.926 666 666 E acquireBuffer: #06 pc 000e3011 /system/lib/libsurfaceflinger.so (android::compositionengine::impl::Output::present(android::compositionengine::CompositionRefreshArgs const&)+92)

　　04-19 19:33:38.926 666 666 E acquireBuffer: #07 pc 000dcfa1 /system/lib/libsurfaceflinger.so (android::compositionengine::impl::CompositionEngine::present(android::compositionengine::CompositionRefreshArgs&)+144)

　　04-19 19:33:38.926 666 666 E acquireBuffer: #08 pc 000baf81 /system/lib/libsurfaceflinger.so (android::SurfaceFlinger::onMessageRefresh()+1280)

　　04-19 19:33:38.926 666 666 E acquireBuffer: #09 pc 000b8b1d /system/lib/libsurfaceflinger.so (android::SurfaceFlinger::onMessageReceived(int, long long)+52)

　　releaseBuffer方法位置：BufferQueueConsumer::releaseBuffer

　　04-19 19:33:38.996 666 666 E releaseBuffer: #00 pc 0004e429 /system/lib/libgui.so (android::BufferQueueConsumer::releaseBuffer(int, unsigned long long, android::sp const&, void*, void*)+72)

　　04-19 19:33:38.996 666 666 E releaseBuffer: #01 pc 0004f3af /system/lib/libgui.so (android::BufferQueueConsumer::releaseBuffer(int, unsigned long long, void*, void*, android::sp const&)+36)

　　04-19 19:33:38.996 666 666 E releaseBuffer: #02 pc 0006498d /system/lib/libgui.so (android::ConsumerBase::releaseBufferLocked(int, android::sp, void*, void*)+140)

　　04-19 19:33:38.996 666 666 E releaseBuffer: #03 pc 00066cab /system/lib/libsurfaceflinger.so (android::BufferLayerConsumer::releasePendingBuffer()+78)

　　04-19 19:33:38.996 666 666 E releaseBuffer: #04 pc 00067b1d /system/lib/libsurfaceflinger.so (android::BufferQueueLayer::releasePendingBuffer(long long)+28)

　　04-19 19:33:38.996 666 666 E releaseBuffer: #05 pc 000bb0bb /system/lib/libsurfaceflinger.so (android::SurfaceFlinger::onMessageRefresh()+1594)

　　04-19 19:33:38.996 666 666 E releaseBuffer: #06 pc 000b8b1d /system/lib/libsurfaceflinger.so (android::SurfaceFlinger::onMessageReceived(int, long long)+52)

　　2.2.3、认识BufferQueueCore

　　BufferQueueCore是bufferqueue实现的具体类。BufferQueueCore管理了几个数据结构。操作这几个数据结构，来实现bufferqueue的dequebuffer等方法。

　　以dequeueBuffer过程来讲，它就是向bufferqueue申请一个GraphicBuffer,用GraphicBuffer来绘制图像。

　　BufferQueueCore中六个对象比较重要：mQueue、mSlot、FreeSlots、FreeBuffers、ActiveBuffers、UnusedBuffers 下面我会一一介绍

　　namespace android {

　　class IConsumerListener;

　　class IProducerListener;

　　class BufferQueueCore : public virtual RefBase {

　　private:

　　BufferQueueDefs::SlotsType mSlots;

　　Fifo mQueue;

　　std::set mFreeSlots;

　　std::list mFreeBuffers;

　　std::list mUnusedSlots;

　　std::set mActiveBuffers;

　　1、mQueue&&mSlot我们先认识这两个最核心的数据结构。

　　class BufferItem {

　　public:

　　enum { INVALID_BUFFER_SLOT = -1 };

　　BufferItem() : mGraphicBuffer(nullptr), mFence(Fence::NO_FENCE) {}

　　~BufferItem() {}

　　sp mGraphicBuffer;

　　sp mFence;

　　Rect mCrop;

　　typedef Vector Fifo;

　　Fifo mQueue;

　　namespace BufferQueueDefs {

　　typedef BufferSlot SlotsType[NUM_BUFFER_SLOTS];

　　}

　　BufferQueueDefs::SlotsType mSlots;

　　我们平时说的bufferqueue队列其实就是说的BufferItem这个mQueue数据容器。BufferItem拥有GraphicBuffer对象

　　而mSlot是一个BufferSlot大小为NUM_BUFFER_SLOTS(等于64)的数组，BufferSlot主要用来绑定GraphicBuffer,BufferSlot和GraphicBuffer一一对应。

　　BufferSlot中有一个BufferState对象，它专门用来表示GraphicBuffer的状态

　　struct BufferSlot {

　　BufferState mBufferState;

　　// BufferState tracks the states in which a buffer slot can be.

　　struct BufferState {

　　// All slots are initially FREE (not dequeued, queued, acquired, or shared).

　　BufferState()

　　: mDequeueCount(0),

　　mQueueCount(0),

　　mAcquireCount(0),

　　mShared(false) {

　　}

　　uint32_t mDequeueCount;

　　uint32_t mQueueCount;

　　uint32_t mAcquireCount;

　　bool mShared;

　　// A buffer can be in one of five states, represented as below:

　　//

　　// | mShared | mDequeueCount | mQueueCount | mAcquireCount |

　　// --------|---------|---------------|-------------|---------------|

　　// FREE | false | 0 | 0 | 0 |

　　// DEQUEUED| false | 1 | 0 | 0 |

　　// QUEUED | false | 0 | 1 | 0 |

　　// ACQUIRED| false | 0 | 0 | 1 |

　　// SHARED | true | any | any | any |

　　2、FreeSlots、FreeBuffers、ActiveBuffers、UnusedBuffers

　　知道了mQueue&&mSlot作用后，我们再来认识他们四个容易了,首先成立这样一个等式

　　mSlots = mFreeSlots + mFreeBuffers + mActiveBuffers + mUnusedSlots

　　mSlots是所有BufferSlot，而其它四个BufferSlot，则表示不同的状态的BufferSlot。

　　mFreeSlots：BufferSlot状态为FREE，且没有GraphicBuffer与之相绑定的slot集合

　　mFreeBuffers：BufferSlot状态为FREE，且有GraphicBuffer与之相绑定的slot集合

　　mActiveBuffers：BufferSlot状态不为FREE（即DEQUEUED、QUEUED、ACQUIRED、SHARED）的slot集合。既然状态不是FREE，那么该BufferSlot必然有一个GraphicBuffer与之相绑定

　　mUnusedSlots：未参与使用的slot集合，由 mMaxBufferCount 决定

　　2.2.4、BufferQueueProducer生产者

　　生产者这边，在bufferqueue流程中，主要负责dequeueBuffer、queueBuffer等流程

　　class BufferQueueProducer : public BnGraphicBufferProducer {

　　public:

　　friend class BufferQueue; // Needed to access binderDied

　　explicit BufferQueueProducer(const sp& core,

　　bool consumerIsSurfaceFlinger = false);

　　~BufferQueueProducer() override;

　　virtual status_t requestBuffer(int slot, sp* buf);

　　virtual status_t dequeueBuffer(int* outSlot, sp* outFence, uint32_t width,

　　uint32_t height, PixelFormat format, uint64_t usage,

　　uint64_t* outBufferAge,

　　FrameEventHistoryDelta* outTimestamps) override;

　　virtual status_t queueBuffer(int slot,

　　const QueueBufferInput& input, QueueBufferOutput* output);

　　.http://www.jb51.net//等方法

　　1、dequeueBuffer

　　status_t BufferQueueProducer::dequeueBuffer(int* outSlot, sp* outFence,

　　uint32_t width, uint32_t height, PixelFormat format,

　　uint64_t usage, uint64_t* outBufferAge,

　　FrameEventHistoryDelta* outTimestamps) {

　　// 获取下一个buffer slot,如果有freeSlot直接拿来用

　　while (found == BufferItem::INVALID_BUFFER_SLOT) {

　　status_t status = waitForFreeSlotThenRelock(FreeSlotCaller::Dequeue, lock, &found);

　　if (status != NO_ERROR) {

　　return status;

　　}

　　...

　　// IGraphicBufferProducer::BUFFER_NEEDS_REALLOCATION 和IGraphicBufferProducer::RELEASE_ALL_BUFFERS标记会走 requestBuffer流程来获取graphicBuffer对应的slot

　　if ((buffer == nullptr) ||

　　buffer->needsReallocation(width, height, format, BQ_LAYER_COUNT, usage))

　　{

　　mSlots[found].mAcquireCalled = false;

　　mSlots[found].mGraphicBuffer = nullptr;

　　mSlots[found].mRequestBufferCalled = false;

　　mSlots[found].mEglDisplay = EGL_NO_DISPLAY;

　　mSlots[found].mEglFence = EGL_NO_SYNC_KHR;

　　mSlots[found].mFence = Fence::NO_FENCE;

　　mCore->mBufferAge = 0;

　　mCore->mIsAllocating = true;

　　returnFlags |= BUFFER_NEEDS_REALLOCATION;

　　}

　　上面摘抄了dequebuffer流程主要的两件事情

　　2、queueBuffer

　　queueBuffer将已填充的缓冲区返回给BufferQueue，即把bufferslot封装成BufferItem返回到BufferItem队列mQueue。

　　status_t BufferQueueProducer::queueBuffer(int slot,

　　const QueueBufferInput &input, QueueBufferOutput *output) {

　　// 构建bufferitem并赋值

　　BufferItem item;

　　item.mAcquireCalled = mSlots[slot].mAcquireCalled;

　　item.mGraphicBuffer = mSlots[slot].mGraphicBuffer;

　　...

　　item.mSlot = slot;

　　item.mFence = acquireFence;

　　item.mFenceTime = acquireFenceTime;

　　//bufferItem 入队

　　if (mCore->mQueue.empty()) {

　　// When the queue is empty, we can ignore mDequeueBufferCannotBlock

　　// and simply queue this buffer

　　mCore->mQueue.push_back(item);

　　frameAvailableListener = mCore->mConsumerListener;

　　} else {

　　// When the queue is not empty, we need to look at the last buffer

　　// in the queue to see if we need to replace it

　　const BufferItem& last = mCore->mQueue.itemAt(

　　mCore->mQueue.size() - 1);

　　if (last.mIsDroppable) {

　　if (!last.mIsStale) {

　　mSlots[last.mSlot].mBufferState.freeQueued();

　　queueBuffer比较简单，主要两步

　　1、构建bufferItem，赋值等

　　2、把bufferItem返回到mQueue队列中

　　2.2.4、BufferQueueConsumer消费者

　　1、acquireBuffer

　　acquireBuffer方法从缓冲队列中尝试取下一个挂起的BufferItem有这些情况：

　　队列为空直接返回；如果缓冲已被获取，返回之前获取的缓冲项；如果expectedPresent标记为非0，缓冲会即将显示；如果缓冲时间戳在将来，不会被获取；

　　status_t BufferQueueConsumer::acquireBuffer(BufferItem* outBuffer,

　　nsecs_t expectedPresent, uint64_t maxFrameNumber) {

　　// 新旧缓冲区显示逻辑，决定显示的buffer

　　if (expectedPresent != 0 && !mCore->mQueue.empty()) {

　　while (mCore->mQueue.size() > 1 && !mCore->mQueue[0].mIsAutoTimestamp) {

　　const BufferItem& bufferItem(mCore->mQueue[1]);

　　...

　　此段逻辑比较简单，就是拿缓存，逻辑主要是怎么拿，最后回调

　　2、releaseBuffer

　　releaseBuffer将bufferslot返回到bufferqueue队列。可以在bufferqueue任在访问时进行，当buffer不再可用，fence机制会发出信号。

　　如果releaseBuffer收到STALE_BUFFER_SLOT信号，那么consumer必须直接放弃所有引用。直接释放。

　　代码就是release为主

　　status_t BufferQueueConsumer::releaseBuffer(int slot, uint64_t frameNumber,

　　const sp& releaseFence, EGLDisplay eglDisplay,

　　EGLSyncKHR eglFence) {

　　sp listener;

　　{ // Autolock scope

　　std::lock_guard lock(mCore->mMutex);

　　if (frameNumber != mSlots[slot].mFrameNumber &&

　　!mSlots[slot].mBufferState.isShared()) {

　　return STALE_BUFFER_SLOT;

　　}

　　if (!mSlots[slot].mBufferState.isAcquired()) {

　　BQ_LOGE("releaseBuffer: attempted to release buffer slot %d "

　　"but its state was %s", slot,

　　mSlots[slot].mBufferState.string());

　　return BAD_VALUE;

　　}

　　mSlots[slot].mEglDisplay = eglDisplay;

　　mSlots[slot].mEglFence = eglFence;

　　mSlots[slot].mFence = releaseFence;

　　mSlots[slot].mBufferState.release();

　　三、bufferqueue总结

　　bufferqueue是整个安卓图形处理的核心，把数据生产者和数据消费者连接起来。

　　生产者dequeuebuffer申请一个缓冲区，并指定宽高等。填充缓冲区数据后用queueBuffer返回到队列。随后aquirebuffer获取缓冲区，消费者处理完后。则返回到队列release

　　以上就是Android开发graphics bufferqueue整体流程的详细内容，更多关于Android graphics bufferqueue的资料请关注脚本之家其它相关文章！

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