Revised thread/timer handling, work queue and scheduling.

Updated quagga thread handling to use qtimers when using the new
qpnexus -- so all timers are qtimers in the new scheme.

Updated work queue handling so that each work queue item is a single
malloced structure, not three.  (Only bgpd and zebra use the work
queue system.)

When using qpnexus the background thread queue is no longer a timer
queue, but simply a list of pending background threads.  When a
background thread is waiting on a timer, it is in the qtimer pile,
same like any other thread.

When using qpnexus, the only remaining quagga thread queues are the
event and ready queues.

Revised the qpnexus loop so that only when there is nothing else to
do will it consider the background threads.

Revised write I/O in the BGP Engine so that all writing is via the
connection's write buffer.  Revised the write I/O in the Routeing
Engine, so that it passes groups of updates in a single mqueue
message.  This all reduces the number of TCP packets sent (because
BGP messages are collected together in the connection's write buffer)
and reduces the number of mqueue messages involved.
(No need for TCP_CORK.)

Code and comments review for the new code.

  modified:   bgpd/bgp_advertise.c
  modified:   bgpd/bgp_common.h
  modified:   bgpd/bgp_connection.c
  modified:   bgpd/bgp_connection.h
  modified:   bgpd/bgp_engine.h
  modified:   bgpd/bgp_fsm.c
  modified:   bgpd/bgp_main.c
  modified:   bgpd/bgp_msg_read.c
  modified:   bgpd/bgp_msg_write.c
  modified:   bgpd/bgp_network.c
  modified:   bgpd/bgp_packet.c
  modified:   bgpd/bgp_packet.h
  modified:   bgpd/bgp_peer.c
  modified:   bgpd/bgp_peer_index.h
  modified:   bgpd/bgp_route.c
  modified:   bgpd/bgp_route_refresh.h
  modified:   bgpd/bgp_session.c
  modified:   bgpd/bgp_session.h
  modified:   bgpd/bgpd.c
  new file:   bgpd/bgpd.cx
  modified:   lib/mqueue.h
  modified:   lib/qpnexus.c
  modified:   lib/qpnexus.h
  modified:   lib/qpselect.c
  modified:   lib/qtimers.c
  modified:   lib/qtimers.h
  modified:   lib/sigevent.c
  modified:   lib/stream.c
  modified:   lib/stream.h
  modified:   lib/thread.c
  modified:   lib/thread.h
  modified:   lib/workqueue.c
  modified:   lib/workqueue.h
  modified:   tests/heavy-wq.c
  modified:   zebra/zebra_rib.c

1 files changed, 7 insertions, 40 deletions

diff --git a/lib/stream.c b/lib/stream.c
index 14c7c589..b4c16977 100644
--- a/lib/stream.c
+++ b/lib/stream.c
@@ -998,46 +998,6 @@ stream_flush (struct stream* s, int fd)
 }
 
 /*------------------------------------------------------------------------------
- * Try to write stream contents to the file descriptor -- assuming non-blocking.
- *
- * Loops if gets EINTR.
- *
- * If writes everything, resets the stream.
- *
- * If does not write everything, then would block.
- *
- * Returns: >= 0 number of bytes left to write
- *            -1 => some error (not including EINTR, EAGAIN or EWOULDBLOCK)
- */
-int
-stream_flush_try(struct stream* s, int fd)
-{
-  int have ;
-  int ret ;
-
-  STREAM_VERIFY_SANE(s);
-
-  while ((have = (s->endp - s->getp)) != 0)
-    {
-      ret = write(fd, s->data + s->getp, have) ;
-      if      (ret > 0)
-        s->getp += ret ;
-      else if (ret < 0)
-        {
-          ret = errno ;
-          if ((ret == EAGAIN) || (ret == EWOULDBLOCK))
-            return have ;
-          if (ret != EINTR)
-            return -1 ;
-        } ;
-    } ;
-
-  s->getp = s->endp = 0;
-
-  return 0 ;
-}
-
-/*------------------------------------------------------------------------------
  * Transfer contents of stream to given buffer and reset stream.
  *
  * Transfers *entire* stream buffer.
@@ -1113,6 +1073,13 @@ stream_fifo_head (struct stream_fifo *fifo)
 }
 
 void
+stream_fifo_reset (struct stream_fifo *fifo)
+{
+  fifo->head = fifo->tail = NULL;
+  fifo->count = 0;
+}
+
+void
 stream_fifo_clean (struct stream_fifo *fifo)
 {
   struct stream *s;