Question

hello i have a client socket application, that connect at the same time, with more than 5000 server with tcpip in linux, but when i open the socket connection, almost all connections, retrieve the error Operation now in progress.

Here my client socket connect code:
how can i doing a good thousands simultaneously socket conecction at the same time???
sorry for my english.
here my code :

struct sockaddr_in echoserver;
struct sockaddr_in sa_loc;
char aport[64];
int optval = 1;
int sock;

memset(&echoserver, 0, sizeof (echoserver));
echoserver.sin_family = AF_INET;  
echoserver.sin_addr.s_addr = inet_addr(server.c_str()); 
echoserver.sin_port = htons(0);     

SOCKET = socket(AF_INET, SOCK_STREAM, 0);
if (SOCKET == -1)
{
 iLastError = errno;
 strLastError = "Create socket Error : "+string(strerror(errno)); 
 connected = false;
 return connected;
}

struct timeval timeouts, timeoutr;
memset(&timeouts, 0, sizeof(timeouts)); // zero timeout struct before use
timeouts.tv_sec = SendTimeOut/1000;
timeouts.tv_usec = 0;
memset(&timeoutr, 0, sizeof(timeoutr)); // zero timeout struct before use
timeoutr.tv_sec = ReceiveTimeOut/1000;
timeoutr.tv_usec = 0;   
int sockopt = setsockopt(SOCKET, SOL_SOCKET, SO_SNDTIMEO, &timeouts, sizeof(timeouts)); 
if (sockopt == -1) 
{
 printf("%s%s","Set socket Option error : ",strerror(errno));
 iLastError = errno;
 strLastError = "setsockopt Error : "+string(strerror(errno));
}
sockopt = setsockopt(SOCKET, SOL_SOCKET, SO_RCVTIMEO, &timeoutr, sizeof(timeoutr)); // 
if (sockopt == -1) 
{
   printf("%s%s","Set socket Option error : ",strerror(errno));
   iLastError = errno;
   strLastError = "setsockopt Error : "+string(strerror(errno));
}

memset(&sa_loc, 0, sizeof(struct sockaddr_in));
sa_loc.sin_family = AF_INET;
sa_loc.sin_port = htons(0);  //8000
sa_loc.sin_addr.s_addr = inet_addr(SourceIP.c_str());
int bindid = bind(SOCKET, (struct sockaddr *)&sa_loc, sizeof(sa_loc));
if (bindid !=0) 
{
 iLastError = errno;
 strLastError = "Bind Error : "+string(strerror(errno));    
}

int conn = connect(SOCKET, (struct sockaddr *) &echoserver, sizeof(echoserver));

if (conn == -1)
{
 strLastError = "Connect Error : "+string(strerror(errno));   
 connected = false;
}
else {
 connected = true;
}

return connected;

wpp

Answer 1

if your variable SendTimeOut is < 1000 then your recv timeout will be 0, and I’m not sure if that is the same as setting O_NONBLOCK, but if it is then it sounds like this is normal process, and you should loop until it succeeds (or you get EISCONN) or fails with a different error code. If this is intended you should probably just set O_NONBLOCK explicitly.

http://linux.die.net/man/3/connect

EINPROGRESS
O_NONBLOCK is set for the file descriptor for the socket and the connection cannot be immediately established; the connection shall be established asynchronously.

…

If the connection cannot be established immediately and O_NONBLOCK is set for the file descriptor for the socket, connect() shall fail and set errno to [EINPROGRESS], but the connection request shall not be aborted, and the connection shall be established asynchronously. Subsequent calls to connect() for the same socket, before the connection is established, shall fail and set errno to [EALREADY].