c++ - WSARecvFrom 阻塞

Question

由于某些原因，当我调用 WSARecvFrom 时，该函数在接收到某些内容之前不会返回。

_socket = WSASocket(AF_INET, SOCK_DGRAM, IPPROTO_UDP, NULL, NULL, WS_OVERLAPPED);
...
sockaddr_in addr = ...
if(bind(_socket, (const sockaddr*)&addr, sizeof(addr)) != EXIT_SUCCESS) { ... }
...
HANDLE _handle = CreateIoCompletionPort((HANDLE)_socket, _ioHandle, NULL, NULL);
...
_recvOverlap->OVERLAP.hEvent = WSACreateEvent();
DWORD sz = 0, flag = 0;
return WSARecvFrom(_socket, _recvBuf, 1, &sz, &flag, (sockaddr*)_recvAddr, &_recvAddrSz, (LPWSAOVERLAPPED)_recvOverlap, NULL);

Answer 1

将 WS_OVERLAPPED(值为 0)更改为 WSA_FLAG_OVERLAPPED(值为 1)。您没有正确创建重叠套接字，因此 _recvOverlap 被 WSARecvFrom() 忽略。