closesocket

#include <rtl.h>

int closesocket (
    int sock);         /* Socket descriptor */

The closesocket function closes an existing socket and releases the socket descriptor. Further references to sock fail with SCK_EINVALID error code.

The argument sock specifies a socket descriptor returned from a previous call to socket.

In blocking mode, which is enabled if the system detects RTX environment, this functions waits until a socket is closed. In non blocking mode, you must call the closesocket function again if the error code SCK_EWOULDBLOCK is returned.

The closesocket function is in the RL-TCPnet library. The prototype is defined in rtl.h.

note

• You must call the socket function before any other function calls to the BSD socket.
• If a negative number is returned, it represents an error code.

The closesocket function returns the following result:

• SCK_SUCCESS
  The function call is successful.
• SCK_EINVALID
  The socket identified with sock is invalid.
• SCK_EWOULDBLOCK
  The function would block, and the socket is set to non blocking mode.
• SCK_ELOCKED
  The sock is locked by another task in RTX environment.

bind, ioctlsocket, socket

#include <rtl.h>

__task void server (void *argv) {
  /* Server task runs in 2 instances. */
  SOCKADDR_IN addr;
  int sock, sd, res;
  int type = (int)argv;
  char dbuf[4];

  while (1) {
    sock = socket (AF_INET, type, 0);

    addr.sin_port        = htons(1001);
    addr.sin_family      = PF_INET;
    addr.sin_addr.s_addr = INADDR_ANY;

    bind (sock, (SOCKADDR *)&addr, sizeof(addr));

    if (type == SOCK_STREAM) {
      listen (sock, 1);
      sd = accept (sock, NULL, NULL);
      closesocket (sock);
      sock = sd;
    }

    while (1) {
      res = recv (sock, dbuf, sizeof (dbuf), 0);
      if (res <= 0) {
        break;
      }
      procrec ((U8 *)dbuf);
    }
    closesocket (sock);
  }
}