你的代码中，调用asio::async_write的回调中，还有判断缓冲中的数据如果没有发生完，接着发送，如：
if (!ec && tcp_sock.is_open() && length > 0 ) {
connection->handle_event(EVT_SEND);
{
ilog("send out length {}",length);
std::lock_guardstd::mutex guard(m.mutex);
m.send_buffer.consume(length);
if (m.send_buffer.size() == 0){
m.is_writing = false;
return ;
}
}
self->do_async_write();
但是asio文档中说，asio::async_write要么发送完所有数据，要么出错，所以，上述异常处理代码是否必要
/// Start an asynchronous operation to write all of the supplied data to a
/// stream.
/**

• This function is used to asynchronously write a certain number of bytes of
• data to a stream. The function call always returns immediately. The
• asynchronous operation will continue until one of the following conditions
• is true:
• @Luokery All of the data in the supplied buffers has been written. That is, the
• bytes transferred is equal to the sum of the buffer sizes.
• @Luokery An error occurred.