1/*	$NetBSD: rwlock_emul.c,v 1.2 2012/02/15 17:55:07 riz Exp $	*/
2
3/*
4 * Copyright (C) 2003 by Darren Reed.
5 *
6 * See the IPFILTER.LICENCE file for details on licencing.
7 *
8 * Id: rwlock_emul.c,v 1.1.4.2 2009/12/27 06:58:07 darrenr Exp
9 */
10
11#include "ipf.h"
12
13#define	EMM_MAGIC	0x97dd8b3a
14
15void eMrwlock_read_enter(rw, file, line)
16eMrwlock_t *rw;
17char *file;
18int line;
19{
20	if (rw->eMrw_magic != EMM_MAGIC) {
21		fprintf(stderr, "%s:eMrwlock_read_enter(%p): bad magic: %#x\n",
22			rw->eMrw_owner, rw, rw->eMrw_magic);
23		abort();
24	}
25	if (rw->eMrw_read != 0 || rw->eMrw_write != 0) {
26		fprintf(stderr,
27			"%s:eMrwlock_read_enter(%p): already locked: %d/%d\n",
28			rw->eMrw_owner, rw, rw->eMrw_read, rw->eMrw_write);
29		abort();
30	}
31	rw->eMrw_read++;
32	rw->eMrw_heldin = file;
33	rw->eMrw_heldat = line;
34}
35
36
37void eMrwlock_write_enter(rw, file, line)
38eMrwlock_t *rw;
39char *file;
40int line;
41{
42	if (rw->eMrw_magic != EMM_MAGIC) {
43		fprintf(stderr, "%s:eMrwlock_write_enter(%p): bad magic: %#x\n",
44			rw->eMrw_owner, rw, rw->eMrw_magic);
45		abort();
46	}
47	if (rw->eMrw_read != 0 || rw->eMrw_write != 0) {
48		fprintf(stderr,
49			"%s:eMrwlock_write_enter(%p): already locked: %d/%d\n",
50			rw->eMrw_owner, rw, rw->eMrw_read, rw->eMrw_write);
51		abort();
52	}
53	rw->eMrw_write++;
54	rw->eMrw_heldin = file;
55	rw->eMrw_heldat = line;
56}
57
58
59void eMrwlock_downgrade(rw, file, line)
60eMrwlock_t *rw;
61char *file;
62int line;
63{
64	if (rw->eMrw_magic != EMM_MAGIC) {
65		fprintf(stderr, "%s:eMrwlock_write_enter(%p): bad magic: %#x\n",
66			rw->eMrw_owner, rw, rw->eMrw_magic);
67		abort();
68	}
69	if (rw->eMrw_read != 0 || rw->eMrw_write != 1) {
70		fprintf(stderr,
71			"%s:eMrwlock_write_enter(%p): already locked: %d/%d\n",
72			rw->eMrw_owner, rw, rw->eMrw_read, rw->eMrw_write);
73		abort();
74	}
75	rw->eMrw_write--;
76	rw->eMrw_read++;
77	rw->eMrw_heldin = file;
78	rw->eMrw_heldat = line;
79}
80
81
82void eMrwlock_exit(rw)
83eMrwlock_t *rw;
84{
85	if (rw->eMrw_magic != EMM_MAGIC) {
86		fprintf(stderr, "%s:eMrwlock_exit(%p): bad magic: %#x\n",
87			rw->eMrw_owner, rw, rw->eMrw_magic);
88		abort();
89	}
90	if (rw->eMrw_read != 1 && rw->eMrw_write != 1) {
91		fprintf(stderr, "%s:eMrwlock_exit(%p): not locked: %d/%d\n",
92			rw->eMrw_owner, rw, rw->eMrw_read, rw->eMrw_write);
93		abort();
94	}
95	if (rw->eMrw_read == 1)
96		rw->eMrw_read--;
97	else if (rw->eMrw_write == 1)
98		rw->eMrw_write--;
99	rw->eMrw_heldin = NULL;
100	rw->eMrw_heldat = 0;
101}
102
103
104void eMrwlock_init(rw, who)
105eMrwlock_t *rw;
106char *who;
107{
108	if (rw->eMrw_magic == EMM_MAGIC) {	/* safe bet ? */
109		fprintf(stderr,
110			"%s:eMrwlock_init(%p): already initialised?: %#x\n",
111			rw->eMrw_owner, rw, rw->eMrw_magic);
112		abort();
113	}
114	rw->eMrw_magic = EMM_MAGIC;
115	rw->eMrw_read = 0;
116	rw->eMrw_write = 0;
117	if (who != NULL)
118		rw->eMrw_owner = strdup(who);
119	else
120		rw->eMrw_owner = NULL;
121}
122
123
124void eMrwlock_destroy(rw)
125eMrwlock_t *rw;
126{
127	if (rw->eMrw_magic != EMM_MAGIC) {
128		fprintf(stderr, "%s:eMrwlock_destroy(%p): bad magic: %#x\n",
129			rw->eMrw_owner, rw, rw->eMrw_magic);
130		abort();
131	}
132	memset(rw, 0xa5, sizeof(*rw));
133}
134