libports: Add ports_request_dead_name_notification ()

This significantly cuts down the boilerplate of
requesting dead-name notifications.

1 files changed, 54 insertions, 0 deletions

diff --git a/libports/request-notification.c b/libports/request-notification.c
new file mode 100644
index 00000000..c7a7ca25
--- /dev/null
+++ b/libports/request-notification.c
@@ -0,0 +1,54 @@
+/* Request dead-name notifications
+
+   Copyright (C) 2021 Free Software Foundation, Inc.
+
+   Written by Sergey Bugaev <bugaevc@gmail.com>
+
+   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"
+#include <mach/notify.h>
+
+error_t
+ports_request_dead_name_notification (void *object, mach_port_t name,
+                                      mach_port_t *previous)
+{
+  error_t err;
+  mach_port_t notify_port;
+  mach_port_t prev;
+
+  if (object)
+    notify_port = ports_port_notify_right (object);
+  else
+    notify_port = MACH_PORT_NULL;
+
+  err = mach_port_request_notification (mach_task_self (), name,
+                                        MACH_NOTIFY_DEAD_NAME, 1,
+                                        notify_port,
+                                        MACH_MSG_TYPE_MAKE_SEND_ONCE,
+                                        &prev);
+  if (err)
+    return err;
+
+  if (previous != NULL)
+    *previous = prev;
+  else if (MACH_PORT_VALID (prev))
+    {
+      err = mach_port_deallocate (mach_task_self (), prev);
+      assert_perror_backtrace (err);
+    }
+
+  return 0;
+}