Initial revision

1 files changed, 114 insertions, 0 deletions

diff --git a/libports/interrupt-notified-rpcs.c b/libports/interrupt-notified-rpcs.c
new file mode 100644
index 00000000..a88e398a
--- /dev/null
+++ b/libports/interrupt-notified-rpcs.c
@@ -0,0 +1,114 @@
+/* Handle interruping rpcs because of notification
+
+   Copyright (C) 1995 Free Software Foundation, Inc.
+
+   Written by Miles Bader <miles@gnu.ai.mit.edu>
+
+   This program is free software; you can redistribute it and/or
+   modify it under the terms of the GNU General Public License as
+   published by the Free Software Foundation; either version 2, or (at
+   your option) any later version.
+
+   This program is distributed in the hope that it will be useful, but
+   WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
+
+#include "ports.h"
+
+/* A linked list of ports for which notification has been requested.  */
+struct ports_notify *_ports_notifications = 0;
+
+/* Free lists for notify structures.  */
+struct ports_notify *_ports_free_ports_notifies = 0;
+struct rpc_notify *_ports_free_rpc_notifies = 0;
+
+/* Interrupt any rpcs on OBJECT that have requested such.  */
+void
+ports_interrupt_notified_rpcs (void *object,
+			       mach_port_t port, mach_msg_id_t what)
+{
+  struct ports_notify *np;
+
+  mutex_lock (&_ports_lock);
+  for (np = _ports_notifications; np; np = np->next)
+    if (np->port == port && np->what == what)
+      {
+	struct rpc_notify *req;
+	for (req = np->reqs; req; req = req->next_req)
+	  if (req->pending)
+	    {
+	      req->pending--;
+	      hurd_thread_cancel (req->rpc->thread);
+	    }
+	break;
+      }
+  mutex_unlock (&_ports_lock);
+}
+
+static void
+remove_req (struct rpc_notify *req)
+{
+  struct ports_notify *np = req->notify;
+
+  /* Take REQ out of the list of notified rpcs.  */
+  if (req->next_req)
+    req->next_req->prev_req_p = req->prev_req_p;
+  *req->prev_req_p = req->next_req;
+
+  if (np->reqs == 0)
+    /* Now NP has no more reqests, so we can free it too.  */
+    {
+      /* Take NP out of the active list... */
+      if (np->next)
+	np->next->prevp = np->prevp;
+      *np->prevp = np->next;
+
+      /* And put it on the free list.  */
+      np->next = _ports_free_ports_notifies;
+      _ports_free_ports_notifies = np;
+
+      if (np->pending)
+	/* And cancel the associated notification.  */
+	{
+	  mach_port_t old;
+	  error_t err =
+	    mach_port_request_notification (mach_task_self (), np->port,
+					    np->what, 0, MACH_PORT_NULL,
+					    MACH_MSG_TYPE_MAKE_SEND_ONCE,
+					    &old);
+	  if (! err && old != MACH_PORT_NULL)
+	    mach_port_deallocate (mach_task_self (), old);
+	}	
+    }
+}
+
+/* Remove RPC from the list of notified rpcs, cancelling any pending
+   notifications.  _PORTS_LOCK should be held.  */
+void
+_ports_remove_notified_rpc (struct rpc_info *rpc)
+{
+  struct rpc_notify *req = rpc->notifies;
+
+  if (req)
+    /* Cancel RPC's notify requests.  */
+    {
+      struct rpc_notify *last = req;
+
+      while (last->next)
+	{
+	  remove_req (last);
+	  last = last->next;
+	}
+      remove_req (last);
+
+      /* Put the whole chain on the free list.  */
+      last->next = _ports_free_rpc_notifies;
+      _ports_free_rpc_notifies = req;
+    }
+}
+