shutdown socket prior to close

asyn/drvAsynSerial/drvAsynIPServerPort.c

@@ -295,8 +295,6 @@ static void connectionListener(void *drvPvt)
     int i;
     portList_t *pl, *p;
     int connected;
-    fd_set read_set;
-    struct timeval select_timeout;
 
     /*
      * Sanity check
@@ -308,13 +306,6 @@ static void connectionListener(void *drvPvt)
             "drvAsynIPServerPort: %s started listening for connections on %s\n",
             tty->portName, tty->serverInfo);
     while (tty->fd != INVALID_SOCKET) {
-        FD_ZERO(&read_set);
-        FD_SET(tty->fd, &read_set);
-        select_timeout.tv_sec  = 0;
-        select_timeout.tv_usec = 50000; /* 0.05 seconds, needs to be less than delay in ttyCleanup */
-        if (select(tty->fd + 1, &read_set, NULL, NULL, &select_timeout) < 1 || !FD_ISSET(tty->fd, &read_set)) {
-            continue;
-        }
         if (tty->socketType == SOCK_DGRAM) {
             if ((tty->UDPbufferPos == 0) && (tty->UDPbufferSize == 0)) {
                 tty->UDPbufferSize = recvfrom(tty->fd, tty->UDPbuffer, THEORETICAL_UDP_MAX_SIZE , 0, NULL, NULL);
@@ -506,9 +497,13 @@ static void ttyCleanup(void *pPvt)
     if (!tty) return;
     if (tty->fd >= 0) {
         asynPrint(tty->pasynUser, ASYN_TRACE_FLOW, "drvAsynIPServerPort:ttyCleanup %s: shutdown socket %d\n", tty->portName, tty->fd);
-        epicsSocketDestroy(tty->fd);
+        SOCKET fd_save = tty->fd;
         tty->fd = INVALID_SOCKET;
-        epicsThreadSleep(0.1); /* wait for accept thread to terminate */
+        /* shutdown then close the socket so accept thread will terminate */
+        shutdown(fd_save, SHUT_RDWR);
+        epicsThreadSleep(0.01); /* give time for shutdown to be noticed prior to close */
+        epicsSocketDestroy(fd_save);
+        epicsThreadSleep(0.1);
     }
     free(tty->portName);
     free(tty->serverInfo);