android4.0 休眠喚醒會出現之前介面

android4.0 休眠喚醒會出現之前介面，我們通過案頭遠程工具可以看到在休眠時候，系統已經進入解鎖介面。可是我們喚醒機器的時候，系統會閃一下之前操作的介面，再進入解鎖介面。所以判斷應該是休眠時候沒有把解鎖介面寫入framebuffer，找到寫framebuffer地方：

if (LIKELY(hw.canDraw())) {        // repaint the framebuffer (if needed)        const int index = hw.getCurrentBufferIndex();        GraphicLog& logger(GraphicLog::getInstance());        logger.log(GraphicLog::SF_REPAINT, index);        handleRepaint();        // inform the h/w that we're done compositing        logger.log(GraphicLog::SF_COMPOSITION_COMPLETE, index);        hw.compositionComplete();        logger.log(GraphicLog::SF_SWAP_BUFFERS, index);        postFramebuffer();        logger.log(GraphicLog::SF_REPAINT_DONE, index);    } else {        // pretend we did the post        hw.compositionComplete();        usleep(16667); // 60 fps period    }

可以看到，是根據hw.canDraw()函數的傳回值跳到不同的入口，再找到hw.canDraw()函數的實現：

bool DisplayHardwareBase::canDraw() const{    return mScreenAcquired;}

所以把操作mScreenAcquired的值的相關代碼去掉就可以了：

--- a/services/surfaceflinger/DisplayHardware/DisplayHardwareBase.cpp+++ b/services/surfaceflinger/DisplayHardware/DisplayHardwareBase.cpp@@ -80,11 +80,13 @@ bool DisplayHardwareBase::DisplayEventThread::threadLoop()     if (err >= 0) {         sp<SurfaceFlinger> flinger = mFlinger.promote();         LOGD("About to give-up screen, flinger = %p", flinger.get());+        /*         if (flinger != 0) {             mBarrier.close();             flinger->screenReleased(0);             mBarrier.wait();         }+        */     }     fd = open(kWakeFileName, O_RDONLY, 0);     do {@@ -95,8 +97,10 @@ bool DisplayHardwareBase::DisplayEventThread::threadLoop()     if (err >= 0) {         sp<SurfaceFlinger> flinger = mFlinger.promote();         LOGD("Screen about to return, flinger = %p", flinger.get());+        /*         if (flinger != 0)             flinger->screenAcquired(0);+        */     }     return true; }