(write_err_cb): Increase the penalty, so we don't process anything

	more from this
(read_from_connection): isc_disable() can fail.  Handle that case.
(check_idle_callback): Make sure the same connection is never
	processed more than once during a call to this function.

src/server/connections.c

 /*
- * $Id: connections.c,v 0.106 2003/07/28 07:52:06 ceder Exp $
+ * $Id: connections.c,v 0.107 2003/07/30 17:58:37 ceder Exp $
  * Copyright (C) 1991-2002  Lysator Academic Computer Association.
  *
  * This file is part of the LysKOM server.
@@ -709,6 +709,7 @@ write_err_cb(struct isc_mcb *UNUSED(cb_mcb),
     if (saved_errno != ECONNRESET && saved_errno != EPIPE)
 	kom_log("Failed to write to client %lu from %s: %s\n",
 		cp->session_no, cp->peer, strerror(saved_errno));
+    cp->penalty += param.max_penalty;
     add_to_kill_list(cp);
 }
 
@@ -865,8 +866,11 @@ read_from_connection(Connection *conn)
 
     if (conn->penalty >= param.max_penalty)
     {
-	isc_disable(conn->isc_session);
-	queue_add(conn);
+	/* isc_disable() will fail if we have received EPIPE on
+	   this socket.  In that case will soon close it, since
+	   write_err_cb() has added it to the kill list. */
+	if (isc_disable(conn->isc_session) == 0)
+	    queue_add(conn);
     }
 }
 
@@ -920,6 +924,8 @@ check_idle_callback(oop_source *UNUSED(source),
 {
     Connection *c;
     Connection *next;
+    Connection *head = NULL;
+    Connection *tail = NULL;
 
     set_time();
     is_idle = !work_done;
@@ -930,7 +936,7 @@ check_idle_callback(oop_source *UNUSED(source),
 	is_idle = FALSE;
 	++penalty_generation;
 
-	for (next = queue_first; next != NULL && !go_and_die; )
+	for (next = queue_first; next != NULL; )
 	{
 	    c = next;
 	    next = next->queue_next;
@@ -938,12 +944,31 @@ check_idle_callback(oop_source *UNUSED(source),
 	    if (c->penalty < param.low_penalty)
 	    {
 		queue_remove(c);
-		isc_enable(c->isc_session);
-		read_from_connection(c);
+
+		if (head == NULL)
+		    head = c;
+		else
+		    tail->queue_next = c;
+		tail = c;
 	    }
 	}
     }
 
+    for (next = head; next != NULL; )
+    {
+	c = next;
+	next = next->queue_next;
+	c->queue_next = NULL;
+	if (isc_enable(c->isc_session) < 0)
+	    restart_kom("failed to re-enable session\n");
+
+	/* The call to read_from_connection() might add the
+	   connection to the queue.  That's why we remove all entries
+	   first, and use a private queue within this function.  */
+	if (!go_and_die)
+	    read_from_connection(c);
+    }
+
     if (!is_idle)
 	enable_idle_check();
 
@@ -978,6 +1003,7 @@ data_available_callback(oop_source *source,
     assert(event == OOP_READ);
     assert(conn->isc_session->fd == fd);
     assert(conn->isc_session->master->event_source == source);
+    assert(conn->on_queue == FALSE);
 
     /* Something arrived, so we are busy.  */
     if (is_idle)