Android Graphics driver binaries preloading - liuyq/android-issues GitHub Wiki

private static void maybePreloadGraphicsDriver() {
     if (!SystemProperties.getBoolean(PROPERTY_DISABLE_GRAPHICS_DRIVER_PRELOADING, false)) {
        nativePreloadGraphicsDriver();
    }
}

void android_internal_os_ZygoteInit_nativePreloadGraphicsDriver(JNIEnv* env, jclass) {
    zygote_preload_graphics();
}

    void zygote_preload_graphics() {
    if (Properties::peekRenderPipelineType() == RenderPipelineType::SkiaGL) {
        // Preload GL driver if HWUI renders with GL backend.
        eglGetDisplay(EGL_DEFAULT_DISPLAY);
    } else {
        // Preload Vulkan driver if HWUI renders with Vulkan backend.
        uint32_t apiVersion;
        vkEnumerateInstanceVersion(&apiVersion);
    }
}

EGLDisplay eglGetDisplay(EGLNativeDisplayType display) {
    ATRACE_CALL();

    if (egl_init_drivers() == EGL_FALSE) {
        return setError(EGL_BAD_PARAMETER, EGL_NO_DISPLAY);
    }

    // Call down the chain, which usually points directly to the impl
    // but may also be routed through layers
    clearError();
    egl_connection_t* const cnx = &gEGLImpl;
    return cnx->platform.eglGetDisplay(display);
}

EGLBoolean egl_init_drivers() {
    EGLBoolean res;
    pthread_mutex_lock(&sInitDriverMutex);
    res = egl_init_drivers_locked();
    pthread_mutex_unlock(&sInitDriverMutex);
    return res;
}
static EGLBoolean egl_init_drivers_locked() {
    if (sEarlyInitState) {
        // initialized by static ctor. should be set here.
        return EGL_FALSE;
    }
    // get our driver loader
    Loader& loader(Loader::getInstance());

    // dynamically load our EGL implementation
    egl_connection_t* cnx = &gEGLImpl;
    cnx->hooks[egl_connection_t::GLESv1_INDEX] = &gHooks[egl_connection_t::GLESv1_INDEX];
    cnx->hooks[egl_connection_t::GLESv2_INDEX] = &gHooks[egl_connection_t::GLESv2_INDEX];
    cnx->dso = loader.open(cnx);
    // Check to see if any layers are enabled and route functions through them
    if (cnx->dso) {
        // Layers can be enabled long after the drivers have been loaded.
        // They will only be initialized once.
        LayerLoader& layer_loader(LayerLoader::getInstance());
        layer_loader.InitLayers(cnx);
    }

    return cnx->dso ? EGL_TRUE : EGL_FALSE;
}

void* Loader::open(egl_connection_t* cnx) {...}