C語言傳遞引數均是以值傳遞(pass by value)，另外也可以傳遞指標(a pointer passed by value)。以下是小編為大家搜尋整理的C語言socket多執行緒程式設計限制客戶端連線數，希望能給大家帶來幫助!更多精彩內容請及時關注我們應屆畢業生考試網!
先上一些多執行緒需要使用的函式定義：
程式碼如下:
DWORD WINAPI ProcessClientRequests(LPVOID lpParam) //新執行緒將會執行的函式定義
{
return 0;
}
HANDLE handler=CreateThread(NULL, 0, ProcessClientRequests, &clientsocket, 0, NULL); //這裡比較簡單，&clientsocket是個指標，是從主執行緒傳入新執行緒的引數
WaitForMultipleObjects(MAXCLIENTS, threads, TRUE, INFINITE); //用來阻塞主執行緒，直到所有建立的子執行緒都完成任務為止，才繼續執行後面的程式碼
for(int i=0;i
{
CloseHandle(threads[i]); //建立的'每個子執行緒的HANDLE都會被儲存在HANDLE陣列中，這個函式用於關閉各個handle所對應的執行緒空間
}
服務器端程式
主執行緒程式碼如下：
程式碼如下:
#define MAXCLIENTS 3 //巨集定義，最多3個客戶端連線
int main()
{
WSADATA wsaData;
WSAStartup(MAKEWORD(2, 2), &wsaData);
HANDLE threads[MAXCLIENTS];
SOCKET s=socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
sockaddr_in sockaddr;
_family=PF_INET;
_addr.S_un.S_addr=inet_addr("");
_port=htons(9000);
bind(s, (SOCKADDR*)&sockaddr, sizeof(SOCKADDR));
listen(s, 1);
printf("listening on port [%d].n", 9000);
int existingClientCount=0;
while(TRUE)
{
SOCKADDR clientAddr;
int size=sizeof(SOCKADDR);
SOCKET clientsocket;
clientsocket=accept(s, &clientAddr, &size);
printf("***SYS*** New client touched.n");
if(existingClientCount
{
threads[existingClientCount++]=CreateThread(NULL, 0, ProcessClientRequests, &clientsocket, 0, NULL); //啟動新執行緒，並且將socket傳入
}
else
{
char* msg="Exceeded Max incoming requests, will refused this connect!rn";
send(clientsocket, msg, strlen(msg)+sizeof(char), NULL); //傳送拒絕連線訊息給客戶端
printf("***SYS*** REFUSED.n");
closesocket(clientsocket); //釋放資源
break;
}
}
printf("Maximize clients occurred for d%", MAXCLIENTS);
WaitForMultipleObjects(MAXCLIENTS, threads, TRUE, INFINITE); //等待所有子執行緒，直到完成為止
closesocket(s);
for(int i=0;i
{
CloseHandle(threads[i]); //清理執行緒資源
}
WSACleanup();
printf("Cleared ");
getchar();
exit(0);
}
子執行緒函式定義
程式碼如下:
DWORD WINAPI ProcessClientRequests(LPVOID lpParam)
{
SOCKET* clientsocket=(SOCKET*)lpParam; //這裡需要強制轉換，注意：指標型別的
char* msg="Hello, my ";
send(*clientsocket, msg, strlen(msg)+sizeof(char), NULL);
printf("***SYS*** HELLO.n");
while(TRUE)
{
char buffer[MAXBYTE]={0};
recv(*clientsocket, buffer, MAXBYTE, NULL);
if(strcmp(buffer, "exit")==0)
{
char* msg_bye="";
send(*clientsocket, msg_bye, strlen(msg_bye)+sizeof(char), NULL);
break;
}
printf("***Client*** %sn", buffer);
}
closesocket(*clientsocket);
return 0;
}
