[apple/xnu.git] / bsd / net / init.c

/*
 * Copyright (c) 2000-2004 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * The contents of this file constitute Original Code as defined in and
 * are subject to the Apple Public Source License Version 1.1 (the
 * "License").  You may not use this file except in compliance with the
 * License.  Please obtain a copy of the License at
 * http://www.apple.com/publicsource and read it before using this file.
 * 
 * This Original Code and all software distributed under the License are
 * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
 * License for the specific language governing rights and limitations
 * under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */

#include <kern/kalloc.h>
#include <libkern/OSAtomic.h>
#include <sys/errno.h>
#include <net/init.h>
#include <libkern/libkern.h>
#include <string.h>

struct init_list_entry {
	struct init_list_entry	*next;
	net_init_func_ptr		func;
};

#define LIST_RAN ((struct init_list_entry*)0xffffffff)
static struct init_list_entry	*list_head = 0;

errno_t
net_init_add(
	net_init_func_ptr init_func)
{
	struct init_list_entry	*entry;
	
	if (init_func == 0) {
		return EINVAL;
	}
	
	/* Check if we've already started */
	if (list_head == LIST_RAN) {
		return EALREADY;
	}
	
	entry = kalloc(sizeof(*entry));
	if (entry == 0) {
		printf("net_init_add: no memory\n");
		return ENOMEM;
	}
	
	bzero(entry, sizeof(*entry));
	entry->func = init_func;
	
	do {
		entry->next = list_head;
		
		if (entry->next == LIST_RAN) {
			/* List already ran, cleanup and call the function */
			kfree(entry, sizeof(*entry));
			return EALREADY;
		}
	} while(!OSCompareAndSwap((UInt32)entry->next, (UInt32)entry,
							  (UInt32*)&list_head));
	
	return 0;
}

__private_extern__ void
net_init_run(void)
{
	struct init_list_entry	*backward_head = 0;
	struct init_list_entry	*forward_head = 0;
	struct init_list_entry	*current = 0;
	
	/*
	 * Grab the list, replacing the head with 0xffffffff to indicate
	 * that we've already run.
	 */
	do {
		backward_head = list_head;
	} while (!OSCompareAndSwap((UInt32)backward_head, (UInt32)LIST_RAN,
							   (UInt32*)&list_head));
	
	/* Reverse the order of the list */
	while (backward_head != 0) {
		current = backward_head;
		backward_head = current->next;
		current->next = forward_head;
		forward_head = current;
	}
	
	/* Call each function pointer registered */
	while (forward_head != 0) {
		current = forward_head;
		forward_head = current->next;
		current->func();
		kfree(current, sizeof(*current));
	}
}
Commit	Line	Data
91447636 A	1	/*
	2	* Copyright (c) 2000-2004 Apple Computer, Inc. All rights reserved.
	3	*
	4	* @APPLE_LICENSE_HEADER_START@
	5	*
37839358 A	6	* The contents of this file constitute Original Code as defined in and
	7	* are subject to the Apple Public Source License Version 1.1 (the
	8	* "License"). You may not use this file except in compliance with the
	9	* License. Please obtain a copy of the License at
	10	* http://www.apple.com/publicsource and read it before using this file.
91447636	11	*
37839358 A	12	* This Original Code and all software distributed under the License are
37839358 A	13	* distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
91447636 A	14	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
91447636 A	15	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
37839358 A	16	* FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
	17	* License for the specific language governing rights and limitations
	18	* under the License.
91447636 A	19	*
	20	* @APPLE_LICENSE_HEADER_END@
	21	*/
	22
	23	#include <kern/kalloc.h>
	24	#include <libkern/OSAtomic.h>
	25	#include <sys/errno.h>
	26	#include <net/init.h>
	27	#include <libkern/libkern.h>
	28	#include <string.h>
	29
	30	struct init_list_entry {
	31	struct init_list_entry *next;
	32	net_init_func_ptr func;
	33	};
	34
	35	#define LIST_RAN ((struct init_list_entry*)0xffffffff)
	36	static struct init_list_entry *list_head = 0;
	37
	38	errno_t
	39	net_init_add(
	40	net_init_func_ptr init_func)
	41	{
	42	struct init_list_entry *entry;
	43
	44	if (init_func == 0) {
	45	return EINVAL;
	46	}
	47
	48	/* Check if we've already started */
	49	if (list_head == LIST_RAN) {
	50	return EALREADY;
	51	}
	52
	53	entry = kalloc(sizeof(*entry));
	54	if (entry == 0) {
	55	printf("net_init_add: no memory\n");
	56	return ENOMEM;
	57	}
	58
	59	bzero(entry, sizeof(*entry));
	60	entry->func = init_func;
	61
	62	do {
	63	entry->next = list_head;
	64
	65	if (entry->next == LIST_RAN) {
	66	/* List already ran, cleanup and call the function */
	67	kfree(entry, sizeof(*entry));
	68	return EALREADY;
	69	}
	70	} while(!OSCompareAndSwap((UInt32)entry->next, (UInt32)entry,
	71	(UInt32*)&list_head));
	72
	73	return 0;
	74	}
	75
	76	__private_extern__ void
	77	net_init_run(void)
	78	{
	79	struct init_list_entry *backward_head = 0;
	80	struct init_list_entry *forward_head = 0;
	81	struct init_list_entry *current = 0;
	82
83	/*
84	* Grab the list, replacing the head with 0xffffffff to indicate
85	* that we've already run.
86	*/
87	do {
88	backward_head = list_head;
89	} while (!OSCompareAndSwap((UInt32)backward_head, (UInt32)LIST_RAN,
90	(UInt32*)&list_head));
91
92	/* Reverse the order of the list */
93	while (backward_head != 0) {
94	current = backward_head;
95	backward_head = current->next;
96	current->next = forward_head;
97	forward_head = current;
98	}
99
100	/* Call each function pointer registered */
101	while (forward_head != 0) {
102	current = forward_head;
103	forward_head = current->next;
104	current->func();
105	kfree(current, sizeof(*current));
106	}
107	}