os: Use NotifyFd for ErrorConnMax

Instead of open-coding a single FD wait, use NotifyFd to wait for the
FD to become readable before returning the error message.

Signed-off-by: Keith Packard <keithp@keithp.com>
Reviewed-by: Adam Jackson <ajax@redhat.com>

1 files changed, 19 insertions, 22 deletions

diff --git a/os/connection.c b/os/connection.c
index 4c1ba4b6d..d001b98ee 100644
--- a/os/connection.c
+++ b/os/connection.c
@@ -863,7 +863,6 @@ EstablishNewConnections(ClientPtr clientUnused, void *closure)
 
     if (!AllocNewConnection(new_trans_conn, newconn, connect_time)) {
         ErrorConnMax(new_trans_conn);
-        _XSERVTransClose(new_trans_conn);
     }
     return TRUE;
 }
@@ -881,37 +880,27 @@ QueueNewConnections(int fd, int ready, void *data)
  *     Fail a connection due to lack of client or file descriptor space
  ************/
 
-#define BOTIMEOUT 200           /* in milliseconds */
-
 static void
-ErrorConnMax(XtransConnInfo trans_conn)
+ConnMaxNotify(int fd, int events, void *data)
 {
-    int fd = _XSERVTransGetConnectionNumber(trans_conn);
-    xConnSetupPrefix csp;
-    char pad[3] = { 0, 0, 0 };
-    struct iovec iov[3];
+    XtransConnInfo trans_conn = data;
     char order = 0;
-    int whichbyte = 1;
-    struct timeval waittime;
-    fd_set mask;
-
-    /* if these seems like a lot of trouble to go to, it probably is */
-    waittime.tv_sec = BOTIMEOUT / MILLI_PER_SECOND;
-    waittime.tv_usec = (BOTIMEOUT % MILLI_PER_SECOND) *
-        (1000000 / MILLI_PER_SECOND);
-    FD_ZERO(&mask);
-    FD_SET(fd, &mask);
-    (void) Select(fd + 1, &mask, NULL, NULL, &waittime);
+
     /* try to read the byte-order of the connection */
     (void) _XSERVTransRead(trans_conn, &order, 1);
     if (order == 'l' || order == 'B' || order == 'r' || order == 'R') {
+        xConnSetupPrefix csp;
+        char pad[3] = { 0, 0, 0 };
+        int whichbyte = 1;
+        struct iovec iov[3];
+
         csp.success = xFalse;
         csp.lengthReason = sizeof(NOROOM) - 1;
         csp.length = (sizeof(NOROOM) + 2) >> 2;
         csp.majorVersion = X_PROTOCOL;
         csp.minorVersion = X_PROTOCOL_REVISION;
-	if (((*(char *) &whichbyte) && (order == 'B' || order == 'R')) ||
-	    (!(*(char *) &whichbyte) && (order == 'l' || order == 'r'))) {
+        if (((*(char *) &whichbyte) && (order == 'B' || order == 'R')) ||
+            (!(*(char *) &whichbyte) && (order == 'l' || order == 'r'))) {
             swaps(&csp.majorVersion);
             swaps(&csp.minorVersion);
             swaps(&csp.length);
@@ -924,6 +913,15 @@ ErrorConnMax(XtransConnInfo trans_conn)
         iov[2].iov_base = pad;
         (void) _XSERVTransWritev(trans_conn, iov, 3);
     }
+    RemoveNotifyFd(trans_conn->fd);
+    _XSERVTransClose(trans_conn);
+}
+
+static void
+ErrorConnMax(XtransConnInfo trans_conn)
+{
+    if (!SetNotifyFd(trans_conn->fd, ConnMaxNotify, X_NOTIFY_READ, trans_conn))
+        _XSERVTransClose(trans_conn);
 }
 
 /************
@@ -1426,7 +1424,6 @@ AddClientOnOpenFD(int fd)
 
     if (!AllocNewConnection(ciptr, fd, connect_time)) {
         ErrorConnMax(ciptr);
-        _XSERVTransClose(ciptr);
         return FALSE;
     }