/*****************************************************************************                      I.MX6 Surfaceflinger 机制* 说明：*     最近需要去分析一下Surfaceflinger工作机制，记录一下相关的文档和主要的* 处理函数。**                                          2016-9-14 深圳 南山平山村 曾剑锋***************************************************************************/一、参考文档：1. Android SurfaceFlinger服务启动过程源码分析http://blog.csdn.net/yangwen123/article/details/118909412. Android 开关机动画显示源码分析http://blog.csdn.net/yangwen123/article/details/116807593. 深入学习EGL http://blog.sina.com.cn/s/blog_602f87700100p1e7.html4. Android hwcomposer模块接口http://blog.sina.com.cn/s/blog_7213e0310102wmc0.html5. Android VSync信号产生过程源码分析http://blog.csdn.net/yangwen123/article/details/169699076. android HAL浅探http://www.cnblogs.com/mr-nop/archive/2013/02/27/2935131.html7. Android： 显示系统模块加载以及调用流程http://blog.csdn.net/hongzg1982/article/details/49681705

二、cat frameworks/native/services/surfaceflinger/SurfaceFlinger.cpp......status_t SurfaceFlinger::readyToRun(){ALOGI(  "SurfaceFlinger's main thread ready to run. ""Initializing graphics H/W...");// initialize EGL for the default displaymEGLDisplay = eglGetDisplay(EGL_DEFAULT_DISPLAY);eglInitialize(mEGLDisplay, NULL, NULL);// Initialize the H/W composer object.  There may or may not be an// actual hardware composer underneath.mHwc = new HWComposer(this,*static_cast<HWComposer::EventHandler *>(this));// initialize the config and contextEGLint format = mHwc->getVisualID();mEGLConfig  = selectEGLConfig(mEGLDisplay, format);mEGLContext = createGLContext(mEGLDisplay, mEGLConfig);LOG_ALWAYS_FATAL_IF(mEGLContext == EGL_NO_CONTEXT,"couldn't create EGLContext");// initialize our non-virtual displaysfor (size_t i=0 ; i<DisplayDevice::NUM_DISPLAY_TYPES ; i++) {DisplayDevice::DisplayType type((DisplayDevice::DisplayType)i);mDefaultDisplays[i] = new BBinder();wp<IBinder> token = mDefaultDisplays[i];// set-up the displays that are already connectedif (mHwc->isConnected(i) || type==DisplayDevice::DISPLAY_PRIMARY) {// All non-virtual displays are currently considered secure.bool isSecure = true;bool isSecure = true;mCurrentState.displays.add(token, DisplayDeviceState(type));sp<FramebufferSurface> fbs = new FramebufferSurface(*mHwc, i);sp<SurfaceTextureClient> stc = new SurfaceTextureClient(static_cast< sp<ISurfaceTexture> >(fbs->getBufferQueue()));sp<DisplayDevice> hw = new DisplayDevice(this,type, isSecure, token, stc, fbs, mEGLConfig);if (i > DisplayDevice::DISPLAY_PRIMARY) {// FIXME: currently we don't get blank/unblank requests// for displays other than the main display, so we always// assume a connected display is unblanked.ALOGD("marking display %d as acquired/unblanked", i);hw->acquireScreen();}mDisplays.add(token, hw);}}//  we need a GL context current in a few places, when initializing//  OpenGL ES (see below), or creating a layer,//  or when a texture is (asynchronously) destroyed, and for that//  we need a valid surface, so it's convenient to use the main display//  for that.sp<const DisplayDevice> hw(getDefaultDisplayDevice());//  initialize OpenGL ES
        DisplayDevice::makeCurrent(mEGLDisplay, hw, mEGLContext);initializeGL(mEGLDisplay);// start the EventThreadmEventThread = new EventThread(this);mEventQueue.setEventThread(mEventThread);// initialize our drawing statemDrawingState = mCurrentState;// We're now ready to accept clients...
        mReadyToRunBarrier.open();// set initial conditions (e.g. unblank default device)
        initializeDisplays();// start boot animation
        startBootAnim();return NO_ERROR;}......三、cat frameworks/native/services/surfaceflinger/DisplayHardware/HWComposer.cpp......// Load and prepare the hardware composer module.  Sets mHwc.void HWComposer::loadHwcModule(){hw_module_t const* module;if (hw_get_module(HWC_HARDWARE_MODULE_ID, &module) != 0) {ALOGE("%s module not found", HWC_HARDWARE_MODULE_ID);return;}int err = hwc_open_1(module, &mHwc);if (err) {ALOGE("%s device failed to initialize (%s)",HWC_HARDWARE_COMPOSER, strerror(-err));return;}if (!hwcHasApiVersion(mHwc, HWC_DEVICE_API_VERSION_1_0) ||hwcHeaderVersion(mHwc) < MIN_HWC_HEADER_VERSION ||hwcHeaderVersion(mHwc) > HWC_HEADER_VERSION) {ALOGE("%s device version %#x unsupported, will not be used",HWC_HARDWARE_COMPOSER, mHwc->common.version);hwc_close_1(mHwc);mHwc = NULL;return;}}......四、cat hardware/imx/mx6/hwcomposer/hwcomposer.cppstatic int hwc_device_open(const struct hw_module_t* module, const char* name,struct hw_device_t** device){printf("fsl hwc_device_open().\n");int status = -EINVAL;if (!strcmp(name, HWC_HARDWARE_COMPOSER)) {struct hwc_context_t *dev;dev = (hwc_context_t*)malloc(sizeof(*dev));/* initialize our state here */// memset(dev, 0, sizeof(*dev));/* initialize the procs */dev->device.common.tag = HARDWARE_DEVICE_TAG;dev->device.common.module = const_cast<hw_module_t*>(module);dev->device.common.close = hwc_device_close;dev->device.prepare = hwc_prepare;dev->device.set = hwc_set;dev->device.common.version = HWC_DEVICE_API_VERSION_1_1;dev->device.registerProcs = hwc_registerProcs;dev->device.eventControl = hwc_eventControl;dev->device.query = hwc_query;dev->device.blank = hwc_blank;dev->device.getDisplayConfigs = hwc_getDisplayConfigs;dev->device.getDisplayAttributes = hwc_getDisplayAttributes;/* our private state goes below here */dev->m_vsync_thread = new VSyncThread(dev);dev->m_vsync_thread = new VSyncThread(dev);dev->m_uevent_thread = new UeventThread(dev);hwc_get_display_info(dev);hw_get_module(GRALLOC_HARDWARE_MODULE_ID, &dev->m_gralloc_module);struct private_module_t *priv_m = (struct private_module_t *)dev->m_gralloc_module;for(int dispid=0; dispid<HWC_NUM_DISPLAY_TYPES; dispid++) {if(dev->mDispInfo[dispid].connected && dev->m_gralloc_module != NULL) {int fbid = dev->mDispInfo[dispid].fb_num;char fbname[HWC_STRING_LENGTH];memset(fbname, 0, sizeof(fbname));sprintf(fbname, "fb%d", fbid);ALOGI("hwcomposer: open framebuffer %s", fbname);dev->mFbDev[dispid] = (framebuffer_device_t*)fbid;dev->m_gralloc_module->methods->open(dev->m_gralloc_module, fbname,(struct hw_device_t**)&dev->mFbDev[dispid]);}}const hw_module_t *hwc_module;if(hw_get_module(HWC_VIV_HARDWARE_MODULE_ID,(const hw_module_t**)&hwc_module) < 0) {ALOGE("Error! hw_get_module viv_hwc failed");goto nor_exit;}if(hwc_open_1(hwc_module, &(dev->m_viv_hwc)) != 0) {ALOGE("Error! viv_hwc open failed");goto nor_exit;}nor_exit:*device = &dev->device.common;ALOGI("%s,%d", __FUNCTION__, __LINE__);return 0;err_exit:if(dev){free(dev);}/****************************************/}return status;}