Question

怎样用setsockopt重新设置SOCKET缓冲区的大小

Answer 1

// 这段代码是改变接系统接收缓冲区大小。每次可以从另一端接收数据大小变大。
int nBufLen;
int nOptlLen;
nErrCode = getsockopt(s, SOL_SOCKET, SO_RCVBUF, (char*)nBufLen, &nOptlLen);
if (SOCKET_ERROR == nErrCode)
{
return EXIT_FAILURE;
}
nBufLen *= 10;
nErrCode = setsockopt(s, SOL_SOCKET, SO_RCVBUF, (char*)&nBufLen, nOptlLen);
if (SOCKET_ERROR == nErrCode)
{
return EXIT_FAILURE;
}
// 检查设置系统接收数据缓冲区是否成功
int uiNewRcvBuf;
int nOptLen;
getsockopt(s, SOL_SOCKET, SO_RCVBUF, (char*)uiNewRcvBuf, &nOptLen);
if (SOCKET_ERROR == nErrCode || uiNewRcvBuf != nBufLen)
{
return EXIT_FAILURE;
}

// 这一段，是更改发送缓冲区大小，使我们每次可以发送比较大的数据。
unsigned int uiOldSize = 0;
unsigned int uiNewSize = 0;
int uiRcvBufLen = 0;
if((uiOldSize = GetSysBuffSize(inSocket)) == 0)
{
// 获取缓冲大小失败
return false;
}
uiRcvBufLen = sizeof(uiBuffSize);
if (SOCKET_ERROR == setsockopt(inSocket, SOL_SOCKET, SO_SNDBUF, (char*)&uiBuffSize, uiRcvBufLen))
{
// 修改系统缓冲区大小失败
return false;
}

// 检查设置系统发送缓冲区是否成功
uiRcvBufLen = sizeof(uiNewSize);
if (SOCKET_ERROR == getsockopt(inSocket, SOL_SOCKET, SO_SNDBUF, (char*) &uiNewSize, &uiRcvBufLen) || uiNewSize == uiOldSize)
{
// 修改系统发送缓冲区失败
return false;
}