From 7385db38d82b26736ba56bc7aec4c79acc420824 Mon Sep 17 00:00:00 2001
From: Linus Nordberg <linus@nordu.net>
Date: Wed, 9 Mar 2011 10:10:04 +0100
Subject: [PATCH] Don't make UDP write event persistant.

rs_packet_send() adds the event again when there's a packet to send
and the write callback does the same if it doesn't drain the queue.
---
 lib/udp.c | 68 ++++++++++++++++++++++++++++++++++++++++++---------------------
 1 file changed, 46 insertions(+), 22 deletions(-)

diff --git a/lib/udp.c b/lib/udp.c
index 3573033..c602cbd 100644
--- a/lib/udp.c
+++ b/lib/udp.c
@@ -14,6 +14,44 @@
 #include "compat.h"
 #include "udp.h"
 
+/* Send one packet, the first in queue.  */
+static void
+_send (struct rs_connection *conn, int fd)
+{
+  ssize_t r = 0;
+  struct rs_packet *pkt = conn->out_queue;
+
+  assert (pkt->rpkt);
+  assert (pkt->rpkt->data);
+
+  /* Send.  */
+  r = compat_send (fd, pkt->rpkt->data, pkt->rpkt->data_len, 0);
+  if (r == -1)
+    {
+      int sockerr = evutil_socket_geterror (pkt->conn->fd);
+      if (sockerr != EAGAIN)
+	rs_err_conn_push_fl (pkt->conn, RSE_SOCKERR, __FILE__, __LINE__,
+			     "%d: send: %d (%s)", fd, sockerr,
+			     evutil_socket_error_to_string (sockerr));
+      return;		/* Don't unlink packet. */
+    }
+
+  /* Unlink the packet.  */
+  conn->out_queue = pkt->next;
+
+  /* If there are more packets in queue, add the write event again.  */
+  if (pkt->conn->out_queue)
+    {
+      r = event_add (pkt->conn->wev, NULL);
+      if (r < 0)
+	{
+	  rs_err_conn_push_fl (pkt->conn, RSE_EVENT, __FILE__, __LINE__,
+			       "event_add: %s", evutil_gai_strerror (r));
+	  return;
+	}
+    }
+}
+
 /* Callback for conn->wev and conn->rev.  FIXME: Rename.  */
 static void
 _evcb (evutil_socket_t fd, short what, void *user_data)
@@ -33,36 +71,22 @@ _evcb (evutil_socket_t fd, short what, void *user_data)
       /* read a single UDP packet and stick it in a new struct
 	 rs_packet */
 
+      /* TODO: Verify that reception of an unsolicited response packet
+	 results in connection being closed.  */
       rs_debug (("%s: UDP read NYI", __func__));
+
+      /* TODO: delete retransmit timer */
     }
   else if (what & EV_WRITE)
     {
       struct rs_packet *pkt = (struct rs_packet *) user_data;
       assert (pkt);
-      /* Socket ready for writing, possibly as a result of a
-	 successful connect.  */
+
       if (!pkt->conn->is_connected)
 	event_on_connect (pkt->conn, pkt);
-      if (pkt->conn->out_queue)
-	{
-	  /* Send one packet, the first.  */
-	  ssize_t r = 0;
-	  struct rs_packet *p = pkt->conn->out_queue;
 
-	  assert (p->rpkt);
-	  assert (p->rpkt->data);
-	  r = compat_send (fd, p->rpkt->data, p->rpkt->data_len, 0);
-	  if (r == -1)
-	    {
-	      int sockerr = evutil_socket_geterror (p->conn->fd);
-	      if (sockerr != EAGAIN)
-		rs_err_conn_push_fl (p->conn, RSE_SOCKERR, __FILE__, __LINE__,
-				     "%d: send: %d (%s)", fd, sockerr,
-				     evutil_socket_error_to_string (sockerr));
-	      return;		/* Don't unlink packet. */
-	    }
-	  pkt->conn->out_queue = p->next;
-	}
+      if (pkt->conn->out_queue)
+	_send (pkt->conn, fd);
     }
 }
 
@@ -72,7 +96,7 @@ udp_init (struct rs_connection *conn, struct rs_packet *pkt)
   assert (!conn->bev);
 
   conn->rev = event_new (conn->evb, conn->fd, EV_READ|EV_PERSIST, _evcb, conn);
-  conn->wev = event_new (conn->evb, conn->fd, EV_WRITE|EV_PERSIST, _evcb, pkt);
+  conn->wev = event_new (conn->evb, conn->fd, EV_WRITE, _evcb, pkt);
   if (!conn->rev || !conn->wev)
     {
       if (conn->rev)
-- 
2.1.4