status_t BufferQueueConsumer::connect(
        const sp<IConsumerListener>& consumerListener, bool controlledByApp) {
    ATRACE_CALL();

    if (consumerListener == nullptr) {
        BQ_LOGE("connect: consumerListener may not be NULL");
        return BAD_VALUE;
    }

    BQ_LOGV("connect: controlledByApp=%s",
            controlledByApp ? "true" : "false");

    std::lock_guard<std::mutex> lock(mCore->mMutex);

    if (mCore->mIsAbandoned) {
        BQ_LOGE("connect: BufferQueue has been abandoned");
        return NO_INIT;
    }

    mCore->mConsumerListener = consumerListener;
    mCore->mConsumerControlledByApp = controlledByApp;

    return NO_ERROR;
}

consumerListener 不能是 nullptr。在 BufferQueueConsumer::disconnect() 中设置 mIsAbandoned 为 true，断开过的 BufferQueue 无法重新连接。