/*
* Copyright (c) 2000-2006 Apple Computer, Inc. All rights reserved.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
*
* This file contains Original Code and/or Modifications of Original Code
* as defined in and that are subject to the Apple Public Source License
* Version 2.0 (the 'License'). You may not use this file except in
* compliance with the License. The rights granted to you under the License
* may not be used to create, or enable the creation or redistribution of,
* unlawful or unlicensed copies of an Apple operating system, or to
* circumvent, violate, or enable the circumvention or violation of, any
* terms of an Apple operating system software license agreement.
*
* Please obtain a copy of the License at
* http://www.opensource.apple.com/apsl/ and read it before using this file.
*
* The Original Code and all software distributed under the License are
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*
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*/
/*
* @OSF_COPYRIGHT@
*/
/*
* Mach Operating System
* Copyright (c) 1991,1990,1989 Carnegie Mellon University
* All Rights Reserved.
*
* Permission to use, copy, modify and distribute this software and its
* documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
* ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* Carnegie Mellon requests users of this software to return to
*
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
*
* any improvements or extensions that they make and grant Carnegie Mellon
* the rights to redistribute these changes.
*/
/*
*/
/*
* File: ipc/ipc_notify.c
* Author: Rich Draves
* Date: 1989
*
* Notification-sending functions.
*/
#include <mach/port.h>
#include <mach/mach_notify.h>
#include <kern/ipc_kobject.h>
#include <ipc/ipc_notify.h>
#include <ipc/ipc_policy.h>
/*!
* @abstract
* Perform a check on whether forming a notification message
* to the specified notification port can be elided.
*
* @discussion
* This is racy but helps avoiding costly messages to be formed
* just to be destroyed because the notification port is already
* dead.
*
* This happens quite a lot during ipc_space_terminate(): all
* receive rights are destroyed first, then other ports.
* This avoids sending notifications to receive rights in that
* space reliably.
*/
static inline bool
ipc_notify_should_send(ipc_port_t notification_port)
{
return ip_active(notification_port);
}
void
ipc_notify_dead_name(ipc_port_t port, mach_port_name_t name)
{
if (ipc_notify_should_send(port)) {
(void)mach_notify_dead_name(port, name);
/* send-once right consumed */
} else {
ipc_port_release_sonce(port);
}
}
void
ipc_notify_send_possible(ipc_port_t port, mach_port_name_t name)
{
if (ipc_notify_should_send(port)) {
(void)mach_notify_send_possible(port, name);
/* send-once right consumed */
} else {
ipc_port_release_sonce(port);
}
}
void
ipc_notify_port_deleted(ipc_port_t port, mach_port_name_t name)
{
if (ipc_notify_should_send(port)) {
(void)mach_notify_port_deleted(port, name);
/* send-once right consumed */
} else {
ipc_port_release_sonce(port);
}
}
void
ipc_notify_port_destroyed(ipc_port_t port, ipc_port_t right)
{
mach_notify_port_destroyed(port, right);
/* send-once and receive rights consumed */
}
ipc_notify_nsenders_t
ipc_notify_no_senders_prepare(ipc_port_t port)
{
ipc_notify_nsenders_t req = { };
ipc_object_type_t type = ip_type(port);
ip_mq_lock_held(port);
if (io_is_kobject_type(type)) {
if (ip_active(port) && ipc_policy(type)->pol_notif_no_senders) {
ip_reference(port);
req.ns_notify = port;
req.ns_mscount = port->ip_mscount;
req.ns_is_kobject = true;
}
} else if (port->ip_nsrequest) {
ipc_release_assert(ipc_policy(type)->pol_notif_no_senders);
req.ns_notify = port->ip_nsrequest;
req.ns_mscount = port->ip_mscount;
req.ns_is_kobject = false;
port->ip_nsrequest = IP_NULL;
}
return req;
}
void
ipc_notify_no_senders_mqueue(ipc_port_t port, mach_port_mscount_t mscount)
{
if (ipc_notify_should_send(port)) {
(void)mach_notify_no_senders(port, mscount);
/* send-once right consumed */
} else {
ipc_port_release_sonce(port);
}
}
void
ipc_notify_no_senders_kobject(ipc_port_t port, mach_port_mscount_t mscount)
{
if (ipc_notify_should_send(port)) {
ipc_policy(port)->pol_kobject_no_senders(port, mscount);
}
ip_release(port);
}
void
ipc_notify_send_once_and_unlock(ipc_port_t port)
{
/*
* clear any reply context:
* no one will be sending the response b/c we are destroying
* the single, outstanding send once right.
*/
port->ip_reply_context = 0;
if (!ip_active(port)) {
ipc_port_release_sonce_and_unlock(port);
} else if (ip_in_space(port, ipc_space_kernel)) {
ipc_kobject_notify_send_once_and_unlock(port);
} else if (ip_full_kernel(port)) {
ipc_port_release_sonce_and_unlock(port);
} else {
ip_mq_unlock(port);
(void)mach_notify_send_once(port);
}
/* send-once right consumed */
}