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Commit ef19414b authored by Jesse Hall's avatar Jesse Hall
Browse files

Transfer HWC release fences to BufferQueue 

After a HWC set, each SurfaceFlinger Layer retrieves the release fence
HWC returned and gives it to the layer's SurfaceTexture. The
SurfaceTexture accumulates the fences into a merged fence until the
next updateTexImage, then passes the merged fence to the BufferQueue
in releaseBuffer.

In a follow-on change, BufferQueue will return the fence along with
the buffer slot in dequeueBuffer. For now, dequeueBuffer waits for the
fence to signal before returning.

The releaseFence default value for BufferQueue::releaseBuffer() is
temporary to avoid transient build breaks with a multi-project
checkin. It'll disappear in the next change.

Change-Id: Iaa9a0d5775235585d9cbf453d3a64623d08013d9
parent a74cbc06

include/gui/BufferQueue.h

+7 −1
Original line number Diff line number Diff line
@@ -23,6 +23,7 @@ 
#include <gui/IGraphicBufferAlloc.h>

#include <gui/ISurfaceTexture.h>



#include <ui/Fence.h>

#include <ui/GraphicBuffer.h>



#include <utils/String8.h>
@@ -218,7 +219,8 @@ public: 
    //

    // Note that the dependencies on EGL will be removed once we switch to using

    // the Android HW Sync HAL.

    status_t releaseBuffer(int buf, EGLDisplay display, EGLSyncKHR fence);

    status_t releaseBuffer(int buf, EGLDisplay display, EGLSyncKHR fence,

            const sp<Fence>& releaseFence = Fence::NO_FENCE);



    // consumerConnect connects a consumer to the BufferQueue.  Only one

    // consumer may be connected, and when that consumer disconnects the
@@ -378,6 +380,10 @@ private: 
        // on a compile-time option) set to a new sync object in updateTexImage.

        EGLSyncKHR mFence;



        // mReleaseFence is a fence which must signal before the contents of

        // the buffer associated with this buffer slot may be overwritten.

        sp<Fence> mReleaseFence;



        // Indicates whether this buffer has been seen by a consumer yet

        bool mAcquireCalled;

include/gui/SurfaceTexture.h

+15 −0
Original line number Diff line number Diff line
@@ -91,6 +91,14 @@ public: 
    // target texture belongs is bound to the calling thread.

    status_t updateTexImage();



    // setReleaseFence stores a fence file descriptor that will signal when the

    // current buffer is no longer being read. This fence will be returned to

    // the producer when the current buffer is released by updateTexImage().

    // Multiple fences can be set for a given buffer; they will be merged into

    // a single union fence. The SurfaceTexture will close the file descriptor

    // when finished with it.

    void setReleaseFence(int fenceFd);



    // setBufferCountServer set the buffer count. If the client has requested

    // a buffer count using setBufferCount, the server-buffer count will

    // take effect once the client sets the count back to zero.
@@ -349,6 +357,13 @@ private: 
        // to EGL_NO_SYNC_KHR when the buffer is created and (optionally, based

        // on a compile-time option) set to a new sync object in updateTexImage.

        EGLSyncKHR mFence;



        // mReleaseFence is a fence which will signal when the buffer

        // associated with this buffer slot is no longer being used by the

        // consumer and can be overwritten. The buffer can be dequeued before

        // the fence signals; the producer is responsible for delaying writes

        // until it signals.

        sp<Fence> mReleaseFence;

    };



    // mEglDisplay is the EGLDisplay with which this SurfaceTexture is currently

include/ui/Fence.h

+1 −0
Original line number Diff line number Diff line
@@ -39,6 +39,7 @@ class Fence 
    : public LightRefBase<Fence>, public Flattenable

{

public:

    static const sp<Fence> NO_FENCE;



    // Construct a new Fence object with an invalid file descriptor.  This

    // should be done when the Fence object will be set up by unflattening

libs/gui/Android.mk

+5 −4
Original line number Diff line number Diff line
@@ -25,14 +25,15 @@ LOCAL_SRC_FILES:= \ 
	CpuConsumer.cpp



LOCAL_SHARED_LIBRARIES := \

	libcutils \

	libutils \

	libbinder \

	libcutils \

	libEGL \

	libGLESv2 \

	libhardware \

	libhardware_legacy \

	libsync \

	libui \

	libEGL \

	libGLESv2 \

	libutils \





LOCAL_MODULE:= libgui

libs/gui/BufferQueue.cpp

+17 −4
Original line number Diff line number Diff line
@@ -307,6 +307,7 @@ status_t BufferQueue::dequeueBuffer(int *outBuf, uint32_t w, uint32_t h, 
    status_t returnFlags(OK);

    EGLDisplay dpy = EGL_NO_DISPLAY;

    EGLSyncKHR fence = EGL_NO_SYNC_KHR;

    sp<Fence> releaseFence;



    { // Scope for the lock

        Mutex::Autolock lock(mMutex);
@@ -318,7 +319,6 @@ status_t BufferQueue::dequeueBuffer(int *outBuf, uint32_t w, uint32_t h, 
        usage |= mConsumerUsageBits;



        int found = -1;

        int foundSync = -1;

        int dequeuedCount = 0;

        bool tryAgain = true;

        while (tryAgain) {
@@ -369,7 +369,6 @@ status_t BufferQueue::dequeueBuffer(int *outBuf, uint32_t w, uint32_t h, 


            // look for a free buffer to give to the client

            found = INVALID_BUFFER_SLOT;

            foundSync = INVALID_BUFFER_SLOT;

            dequeuedCount = 0;

            for (int i = 0; i < mBufferCount; i++) {

                const int state = mSlots[i].mBufferState;
@@ -393,7 +392,6 @@ status_t BufferQueue::dequeueBuffer(int *outBuf, uint32_t w, uint32_t h, 
                        bool isOlder = mSlots[i].mFrameNumber <

                                mSlots[found].mFrameNumber;

                        if (found < 0 || isOlder) {

                            foundSync = i;

                            found = i;

                        }

                    }
@@ -484,6 +482,7 @@ status_t BufferQueue::dequeueBuffer(int *outBuf, uint32_t w, uint32_t h, 
            mSlots[buf].mGraphicBuffer = graphicBuffer;

            mSlots[buf].mRequestBufferCalled = false;

            mSlots[buf].mFence = EGL_NO_SYNC_KHR;

            mSlots[buf].mReleaseFence.clear();

            mSlots[buf].mEglDisplay = EGL_NO_DISPLAY;



            returnFlags |= ISurfaceTexture::BUFFER_NEEDS_REALLOCATION;
@@ -491,7 +490,9 @@ status_t BufferQueue::dequeueBuffer(int *outBuf, uint32_t w, uint32_t h, 


        dpy = mSlots[buf].mEglDisplay;

        fence = mSlots[buf].mFence;

        releaseFence = mSlots[buf].mReleaseFence;

        mSlots[buf].mFence = EGL_NO_SYNC_KHR;

        mSlots[buf].mReleaseFence.clear();

    }  // end lock scope



    if (fence != EGL_NO_SYNC_KHR) {
@@ -507,6 +508,16 @@ status_t BufferQueue::dequeueBuffer(int *outBuf, uint32_t w, uint32_t h, 
        eglDestroySyncKHR(dpy, fence);

    }



    if (releaseFence.get()) {

        int err = releaseFence->wait(1000);

        if (err == -ETIME) {

            ALOGE("dequeueBuffer: timeout waiting for release fence");

        } else if (err != NO_ERROR) {

            ALOGE("dequeueBuffer: error waiting for sync fence: %d", err);

        }

        releaseFence.clear();

    }



    ST_LOGV("dequeueBuffer: returning slot=%d buf=%p flags=%#x", *outBuf,

            mSlots[*outBuf].mGraphicBuffer->handle, returnFlags);
@@ -846,6 +857,7 @@ void BufferQueue::freeBufferLocked(int i) { 
        eglDestroySyncKHR(mSlots[i].mEglDisplay, mSlots[i].mFence);

        mSlots[i].mFence = EGL_NO_SYNC_KHR;

    }

    mSlots[i].mReleaseFence.clear();

}



void BufferQueue::freeAllBuffersLocked() {
@@ -896,7 +908,7 @@ status_t BufferQueue::acquireBuffer(BufferItem *buffer) { 
}



status_t BufferQueue::releaseBuffer(int buf, EGLDisplay display,

        EGLSyncKHR fence) {

        EGLSyncKHR fence, const sp<Fence>& releaseFence) {

    ATRACE_CALL();

    ATRACE_BUFFER_INDEX(buf);
@@ -908,6 +920,7 @@ status_t BufferQueue::releaseBuffer(int buf, EGLDisplay display, 


    mSlots[buf].mEglDisplay = display;

    mSlots[buf].mFence = fence;

    mSlots[buf].mReleaseFence = releaseFence;



    // The buffer can now only be released if its in the acquired state

    if (mSlots[buf].mBufferState == BufferSlot::ACQUIRED) {