HarmonyOS 鸿蒙Next：Native里连续的像素刷新应该怎么做

HarmonyOS 鸿蒙Next：Native里连续的像素刷新应该怎么做

目前遇到问题，使用XComponent连续对同一区域buffer刷新，第一帧渲染正常的情况下，第二帧渲染前，一定会黑屏一下。imagePixel 一直是同一个，外部会有一次像素copy。不知道问题出在哪里？ 即使连续的将 imagePixel 全部设置为全红色，一样会有黑屏问题

void PluginRender::RefreshBitmap(std::string &id, gpointer imagePixel, gint x, gint y, gint width, gint height) {
    PluginRender *render = PluginRender::GetInstance(id);
    if (render == nullptr) {
        OH_LOG_Print(LOG_APP, LOG_ERROR, 0, PluginRenderTag, "RefreshBitmap render = null");
        return;
    }
    // 通过 OH_NativeWindow_NativeWindowRequestBuffer 获取 OHNativeWindowBuffer 实例
    OHNativeWindowBuffer *buffer = nullptr;
    int releaseFenceFd = -1;
    int32_t ret = OH_NativeWindow_NativeWindowRequestBuffer(render->nativeWindow_, &buffer, &releaseFenceFd);
    if (ret != 0 || buffer == nullptr) {
        OH_LOG_Print(LOG_APP, LOG_ERROR, 0, PluginRenderTag, "RefreshBitmap failed, ret != 0");
        return;
    }
    OH_LOG_Print(LOG_APP, LOG_ERROR, 0, PluginRenderTag, "RefreshBitmap OH_NativeWindow_NativeWindowRequestBuffer, fenceFd = %{public}d", releaseFenceFd);
    BufferHandle *bufferHandle = OH_NativeWindow_GetBufferHandleFromNative(buffer);
    uint32_t *mappedAddr = static_cast<uint32_t *>(
        // 使用内存映射函数mmap将bufferHandle对应的共享内存映射到用户空间，可以通过映射出来的虚拟地址向bufferHandle中写入图像数据
        // bufferHandle->virAddr是bufferHandle在共享内存中的起始地址，bufferHandle->size是bufferHandle在共享内存中的内存占用大小
        mmap(bufferHandle->virAddr, bufferHandle->size, PROT_READ | PROT_WRITE, MAP_SHARED, bufferHandle->fd, 0));
    if (mappedAddr == MAP_FAILED) {
        OH_LOG_Print(LOG_APP, LOG_ERROR, 0, PluginRenderTag, "RefreshBitmap mmap failed");
        return;
    }

    int retCode = -1;
    uint32_t timeout = 3000;
    if (releaseFenceFd != -1) {
        struct pollfd pollfds = {0};
        pollfds.fd = releaseFenceFd;
        pollfds.events = POLLIN;
        do {
            retCode = poll(&pollfds, 1, timeout);
        } while (retCode == -1 && (errno == EINTR || errno == EAGAIN));
        close(releaseFenceFd); // 防止fd泄漏
    }

    // 画完后获取像素地址，地址指向的内存包含画布画的像素数据
    uint32_t *value = static_cast<uint32_t *>(imagePixel);

    // 使用mmap获取到的地址来访问内存
    uint32_t *pixel = static_cast<uint32_t *>(mappedAddr);
    for (uint32_t x = 0; x < width; x++) {
        for (uint32_t y = 0; y < height; y++) {
            *pixel++ = *value++;
        }
    }

    // 如果Region中的Rect为nullptr,或者rectNumber为0，则认为OHNativeWindowBuffer全部有内容更改。
    Region region;
    region.rectNumber = 1;
    region.rects = new Region::Rect[1]{{x, y, static_cast<uint32_t>(width), static_cast<uint32_t>(height)}};

    OH_LOG_Print(LOG_APP, LOG_DEBUG, 0, PluginRenderTag, "RefreshBitmap OH_NativeWindow_NativeWindowFlushBuffer before, x:%{public}d, y:%{public}d, w:%{public}d, h:%{public}d", region.rects[0].x,
                 region.rects[0].y, region.rects[0].w, region.rects[0].h);
    int acquireFenceFd = -1;
    // 通过OH_NativeWindow_NativeWindowFlushBuffer 提交给消费者使用，例如：显示在屏幕上。
    int32_t flushBufferRet = OH_NativeWindow_NativeWindowFlushBuffer(render->nativeWindow_, buffer, acquireFenceFd, region);
    // 内存使用完记得去掉内存映射
    int munmapRet = munmap(mappedAddr, bufferHandle->size);
    OH_LOG_Print(LOG_APP, LOG_DEBUG, 0, PluginRenderTag, "RefreshBitmap OH_NativeWindow_NativeWindowFlushBuffer, flushBufferRet = %{public}d, munmapRet = %{public}d,", flushBufferRet, munmapRet);
}