Method sendQueryAsync

src/QueryPipeline/RemoteQueryExecutor.cpp:493–522

}

int RemoteQueryExecutor::sendQueryAsync()
{
#if defined(OS_LINUX)
    LockAndBlocker lock(was_cancelled_mutex);
    if (was_cancelled)
        return -1;

    if (!read_context)
        read_context = std::make_unique<ReadContext>(
            *this,
            /*suspend_when_query_sent*/ true,
            read_packet_type_separately);

    /// If query already sent, do nothing. Note that we cannot use sent_query flag here,
    /// because we can still be in process of sending scalars or external tables.
    if (read_context->isQuerySent())
        return -1;

    read_context->resume();

    if (read_context->isQuerySent())
        return -1;

    ProfileEvents::increment(ProfileEvents::SuspendSendingQueryToShard); /// Mostly for testing purposes.
    return read_context->getFileDescriptor();
#else
    sendQuery();
    return -1;
#endif
}

Block RemoteQueryExecutor::readBlock()
{