首先，我想提一下，在尝试将其集成到我自己的GUI之前，我已经经历了很多套接字线程教程，但我仍然认为自己对这个主题还是比较新的。
我有一个用python编写的服务器，它打开一个套接字并通过localhost启动一个线程，并监听客户端的端口：
def StartThread():
tcpsock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
tcpsock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
tcpsock.bind((TCP_IP, TCP_PORT))
threads = []
tcpsock.listen(5)
print "Waiting for incoming connections from client..."
(conn, (ip,port)) = tcpsock.accept()
print 'Got connection from ', (ip,port)
newthread = ClientThread(ip,port,conn, 1)
newthread.start()
return newthread
这是ClientThread类：
class ClientThread(Thread):
def __init__(self,ip,port,sock, status):
Thread.__init__(self)
self.ip = ip
self.port = port
self.sock = sock
self.status = 1
print " New thread started for "+ip+":"+str(port)
运行服务器代码后，单击C ++ GUI上的一个按钮，该按钮根据Microsoft Winsock客户端模板运行客户端代码StartConnection（）。
void CPSR_CRSDlg::OnBnClickedInit2()
{
if(!checkTimerStarted())
// Set mmtimer to aquire the data
{
m_ntimerID = timeSetEvent( TIMERINTRRVAL,
1,
timerHandler,
0,
TIME_PERIODIC);
SetTimer(1,TIMERINTRRVAL_2,NULL);
m_bTimer_started = true;
}
StartConnection();
}
连接确实成功启动，python代码打印出连接和线程的地址，但随后我的GUI冻结，这样我就无法点击任何其他按钮来实际通过连接发送数据。
为什么我的申请会冻结？我没有正确地实例化线程吗？
StartConnection（）代码不在msdn网站上，但如果需要，这里是我稍加修改的版本：
void StartConnection(){
//printf("Connection Starting... \n");
WSADATA wsaData;
ConnectSocket = INVALID_SOCKET;
struct addrinfo *result = NULL,
*ptr = NULL,
hints;
int argc = 2;
// Validate the parameters
if (argc != 2) {
printf("usage: %s server-name\n", "client");
return;
}
// Initialize Winsock
iResult = WSAStartup(MAKEWORD(2,2), &wsaData);
if (iResult != 0) {
printf("WSAStartup failed with error: %d\n", iResult);
return;
}
ZeroMemory( &hints, sizeof(hints) );
hints.ai_family = AF_UNSPEC;
hints.ai_socktype = SOCK_STREAM;
hints.ai_protocol = IPPROTO_TCP;
// Resolve the server address and port
//iResult = getaddrinfo(argv[1], DEFAULT_PORT, &hints, &result);
iResult = getaddrinfo("localhost", DEFAULT_PORT, &hints, &result);
if ( iResult != 0 ) {
printf("getaddrinfo failed with error: %d\n", iResult);
WSACleanup();
return;
}
// Attempt to connect to an address until one succeeds
for(ptr=result; ptr != NULL ;ptr=ptr->ai_next) {
// Create a SOCKET for connecting to server
ConnectSocket = socket(ptr->ai_family, ptr->ai_socktype,
ptr->ai_protocol);
if (ConnectSocket == INVALID_SOCKET) {
printf("socket failed with error: %ld\n", WSAGetLastError());
WSACleanup();
return;
}
// Connect to server.
iResult = connect( ConnectSocket, ptr->ai_addr, (int)ptr->ai_addrlen);
if (iResult == SOCKET_ERROR) {
closesocket(ConnectSocket);
ConnectSocket = INVALID_SOCKET;
continue;
}
break;
}
freeaddrinfo(result);
if (ConnectSocket == INVALID_SOCKET) {
printf("Unable to connect to server!\n");
WSACleanup();
return;
}
return;
}
void StopConnection(){
closesocket(ConnectSocket);
WSACleanup();
return;
}
void SendJointValues(double *joints){
iResult = recv(ConnectSocket, recvbuf, recvbuflen, 0);
j = parseJSON(joints[0],joints[1],joints[2],joints[3], \
joints[4],joints[5]);
int x = send(ConnectSocket, j, strlen(j), 0);
//iResult = recv(ConnectSocket, recvbuf, recvbuflen, 0);
}
修改
在我通过服务器发送数据后，GUI会再次响应，然后客户端成功发回一次数据。但是在这次交换之后，GUI再次冻结，直到发送更多数据。
以下是服务器的发送+接收部分：
def receiveData(self):
while (self.status == 1):
joints = [0,0,0,0,0,0]
self.sock.sendall('send')
print "Data Sent!"
data = self.sock.recv(4096)
print "Data received: ", data
self.checkStatus(data)
print "Status is: ", self.status
if (self.status == 1):
data_loaded = json.loads(data)
joints = self.createJointArr(data_loaded['Joints'])
time.sleep(0.5)
print joints
return joints
在此Timer函数中调用客户端中的SendJointValues（）：
void CPSR_CRSDlg::OnTimer(UINT_PTR nIDEvent)
{
CString str;
long Position;
double engPosition;
double dblPosition;
double dblSpeed;
bool ret;
// Arch
USB4_01.Controller_3.getEncoderPosition(Position);
countTodegree(Position,engPosition,ARCH);
str.Format(_T("%10.2f"),engPosition);
m_staPosArch.SetWindowText(str);
// Wrist Pitch
USB4_01.Controller_2.getEncoderPosition(Position);
countTodegree(Position,engPosition,TILT);
str.Format(_T("%10.2f"),engPosition);
m_staPosPitch.SetWindowText(str);
// Linear
USB4_02.Controller_1.getEncoderPosition(Position);
countTodegree(Position,engPosition,LINEAR);
str.Format(_T("%10.2f"),engPosition);
m_staPosLinear.SetWindowText(str);
// Turret
USB4_02.Controller_2.getEncoderPosition(Position);
countTodegree(Position,engPosition,TURRET);
str.Format(_T("%10.2f"),engPosition);
m_staPosTurret.SetWindowText(str);
// Roll
USB4_02.Controller_4.getEncoderPosition(Position);
countTodegree(Position,engPosition,ROLL);
str.Format(_T("%10.2f"),engPosition);
m_staPosRoll.SetWindowText(str);
// Drill/Tool
USB4_02.Controller_3.getEncoderPosition(Position);
countTodegree(-Position,engPosition,DRILL);
str.Format(_T("%10.2f"),engPosition);
m_staPosDrill.SetWindowText(str);
// For Penetrate joint
if(JntPenetration.isInitialized())
{
// Get Position feedback
ret = JntPenetration.getPosition(dblPosition);
if(ret) // get position feedback successfully
{
Position = (long) dblPosition;
countTodegree(Position,engPosition,PENETRATE);
str.Format(_T("%10.2f"),engPosition);
m_staPosPenetrate.SetWindowText(str);
m_dCurentPentrationPosition = engPosition;
}
// Get Speed feedback;
if(m_bDrilling_started)
{
// Penetration position close enough AND At least on cycle reached
if( (abs(engPosition - m_dDrilling_target_position) < 0.1) &&(m_Direction_Changed == true))
m_bPenetrationStopped = true;
else
m_bPenetrationStopped = false;
//JntPenetration.getSpeed(dblSpeed);
//if(dblSpeed < .05 )
// m_bPenetrationStopped = true;
//else
// m_bPenetrationStopped = false;
}
}
SendJointValues(JointArray);
// For drilling motion control
if(m_bDrilling_started)
drilingProcedure();
CDialog::OnTimer(nIDEvent);
}