【发布时间】:2012-12-17 04:08:35
【问题描述】:
我有一个服务器,它为连接到它的每个客户端生成一个线程。然后线程处理向客户端接收/发送数据。这是我的服务器代码:
//////////////
// START //
/////////////
while( 1 )
{
if( listen(serverSocket, SOMAXCONN) == SOCKET_ERROR )
{
printf( "Listen failed with error: %ld\n", WSAGetLastError() );
break;
}
/*
* wait for clients...
*/
clientSocket = accept(serverSocket,
(struct sockaddr *)&clientSockAddr,
&clientSockAddrLen);
if( clientSocket == INVALID_SOCKET )
{
printf("%d:accept failed\n", WSAGetLastError());
closesocket(serverSocket);
WSACleanup();
return 1;
}
printf("Client accepted: IP: %s PORT: %d\n",
inet_ntoa(clientSockAddr.sin_addr),
clientSockAddr.sin_port );
THREADDATA threadData = { clientSocket };
sprintf_s(threadData.ip, "%s", inet_ntoa(clientSockAddr.sin_addr));
// spawn a thread for each client
hthread = CreateThread(
NULL, // don't inherit handle
0, // use default size for the executable
processClient,
(pTHREADDATA)&threadData, // thread data
0, // run right away
&threadId );
}
这是我的线程函数的样子:
/*
called by thread for each client
*/
DWORD WINAPI processClient(LPVOID lpParam)
{
int numBytesRecvd = 0,
numBytesSent = 0,
index = 0,
nLeft = SIZE,
TOTAL = SIZE;
char buff[SIZE];
int run = 1;
char msg[MSG_SIZE];
pTHREADDATA td = (pTHREADDATA)lpParam;
/* keep processing client */
while (run)
{
memset(buff, 0, SIZE);
numBytesRecvd = recv(td->clientSocket, buff, nLeft, 0);
/* CLIENT EXITED */
if( !strcmp(buff, "exit") )
{
printf("Client exited!\n");
run = 0;
}
if( numBytesRecvd > 0 )
{
printf("< %s\n", buff);
}
if (numBytesRecvd == 0)
{
printf("Client closed!\n");
run = 0;
}
if( numBytesRecvd == SOCKET_ERROR )
{
printf("%d:Recieve error!\n", WSAGetLastError());
run = 0;
}
}
closesocket(td->clientSocket);
ExitThread(0);
return 0;
}
问题:
所以我启动了服务器和客户端,比如 client1(从 win 7 中的命令提示符),一切都很好。当我在 client1 终端输入内容时,它会在服务器终端打印。
现在我启动另一个客户端 client2,它连接到服务器,并且我输入的任何内容都会显示在服务器上,但是现在当我在 client1 上输入内容时,它不会显示在服务器终端上。
所以基本上每次我启动一个新客户端时,只有那个客户端可以与服务器通信,旧客户端不能!!!但我认为线程会继续处理每个客户端?还是windows中的cmd提示符不是线程安全的?
【问题讨论】:
标签: multithreading thread-safety winsock createthread