pflocal: Handle non-blocking connect with no pending acceptors.

* pflocal/connq.h (struct connq_request): Remove forward.
(connq_listen): Wait for a request to be queued not until there is
a connection attempt.  Remove REQ parameter.  Update callers.
(connq_request_complete): Remove declaration.
(connq_connect): Wait for a slot to queue a request not until
there is an acceptor.  Remove SOCK parameter.  Update callers.
(connq_connect_complete): New declaration.
(connq_connect_cancel): New declaration.
* pflocal/connq.c (struct connq): Remove fields noqueue, queue, length,
head and tail.  Add fields head, tail, count, max, connectors and
num_connectors.  That is, replace the circular buffer with a
singly linked list.
(qnext): Remove function.
(struct connq_request): Remove field signal, lock, completed and
err.  Add field next.
(connq_request_init): Rewrite according to new semantics.
(connq_request_enqueue): New function.
(connq_request_dequeue): New function.
(connq_create): Update according to new semantics.
(connq_destroy): Likewise.
(connq_listen): Rewrite to not block until there is a connector
but until there is a request in the queue.
(connq_request_complete): Remove function.
(connq_connect): Rewrite to not block until there is an acceptor
but until there is space for a request.
(connq_connect_complete): New function.
(connq_connect_cancel): New function.
(connq_compress): Remove dead code.
(connq_set_length): Rewrite.
* pflocal/socket.c (S_socket_connect): Create the server socket here...
(S_socket_accept): ... not here.

1 files changed, 38 insertions, 36 deletions

diff --git a/pflocal/socket.c b/pflocal/socket.c
index a0e5b1da..64a80a46 100644
--- a/pflocal/socket.c
+++ b/pflocal/socket.c
@@ -1,6 +1,6 @@
 /* Socket-specific operations
 
-   Copyright (C) 1995, 2008, 2010 Free Software Foundation, Inc.
+   Copyright (C) 1995, 2008, 2010, 2012 Free Software Foundation, Inc.
 
    Written by Miles Bader <miles@gnu.ai.mit.edu>
 
@@ -112,7 +112,7 @@ S_socket_connect (struct sock_user *user, struct addr *addr)
 	  else if (sock->flags & SOCK_CONNECTED)
 	    /* SOCK_CONNECTED is only set for connection-oriented sockets,
 	       which can only ever connect once.  [If we didn't do this test
-	       here, it would eventually fail when it the listening socket
+	       here, it would eventually fail when the listening socket
 	       tried to accept our connection request.]  */
 	    err = EISCONN;
 	  else
@@ -120,16 +120,35 @@ S_socket_connect (struct sock_user *user, struct addr *addr)
 	      /* Assert that we're trying to connect, so anyone else trying
 	         to do so will fail with EALREADY.  */
 	      sock->connect_queue = cq;
-	      mutex_unlock (&sock->lock); /* Unlock SOCK while waiting.  */
+	      /* Unlock SOCK while waiting.  */
+	      mutex_unlock (&sock->lock);
 
-	      /* Try to connect.  */
-	      err = connq_connect (cq, sock->flags & SOCK_NONBLOCK, sock);
+	      err = connq_connect (peer->listen_queue,
+				   sock->flags & SOCK_NONBLOCK);
+	      if (!err)
+		{
+		  struct sock *server;
+
+		  err = sock_clone (peer, &server);
+		  if (!err)
+		    {
+		      err = sock_connect (sock, server);
+		      if (!err)
+			connq_connect_complete (peer->listen_queue, server);
+		      else
+			sock_free (server);
+		    }
 
-	      /* We can safely set CONNECT_QUEUE to NULL, as no one else can
+	          mutex_lock (&sock->lock);
+		  if (err)
+		    connq_connect_cancel (peer->listen_queue);
+		}
+
+	      /* We must set CONNECT_QUEUE to NULL, as no one else can
 		 set it until we've done so.  */
-	      mutex_lock (&sock->lock);
 	      sock->connect_queue = NULL;
 	    }
+
 	  mutex_unlock (&sock->lock);
 	}
       else
@@ -159,42 +178,25 @@ S_socket_accept (struct sock_user *user,
   err = ensure_connq (sock);
   if (!err)
     {
-      struct connq_request *req;
       struct sock *peer_sock;
 
-      err =
-	connq_listen (sock->listen_queue, sock->flags & SOCK_NONBLOCK,
-		      &req, &peer_sock);
+      err = connq_listen (sock->listen_queue, sock->flags & SOCK_NONBLOCK,
+			  &peer_sock);
       if (!err)
 	{
-	  struct sock *conn_sock;
-
-	  err = sock_clone (sock, &conn_sock);
+	  struct addr *peer_addr;
+	  *port_type = MACH_MSG_TYPE_MAKE_SEND;
+	  err = sock_create_port (peer_sock, port);
+	  if (!err)
+	    err = sock_get_addr (peer_sock, &peer_addr);
 	  if (!err)
 	    {
-	      err = sock_connect (conn_sock, peer_sock);
-	      if (!err)
-		{
-		  struct addr *peer_addr;
-		  *port_type = MACH_MSG_TYPE_MAKE_SEND;
-		  err = sock_create_port (conn_sock, port);
-		  if (!err)
-		    err = sock_get_addr (peer_sock, &peer_addr);
-		  if (!err)
-		    {
-		      *peer_addr_port = ports_get_right (peer_addr);
-		      *peer_addr_port_type = MACH_MSG_TYPE_MAKE_SEND;
-		      ports_port_deref (peer_addr);
-		    }
-		  else
-		    /* TEAR DOWN THE CONNECTION XXX */;
-		}
-	      if (err)
-		sock_free (conn_sock);
+	      *peer_addr_port = ports_get_right (peer_addr);
+	      *peer_addr_port_type = MACH_MSG_TYPE_MAKE_SEND;
+	      ports_port_deref (peer_addr);
 	    }
-
-	  /* Communicate any error (or success) to the connecting thread.  */
-	  connq_request_complete (req, err);
+	  else
+	    /* TEAR DOWN THE CONNECTION XXX */;
 	}
     }