1 /*	$FreeBSD: stable/9/contrib/ipfilter/lib/rwlock_emul.c 170268 2007-06-04 02:54:36Z darrenr $	*/
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 1.1.4.1 2006/06/16 17:21:17 darrenr Exp $
9  */
10 
11 #include "ipf.h"
12 
13 #define	EMM_MAGIC	0x97dd8b3a
14 
eMrwlock_read_enter(rw,file,line)15 void eMrwlock_read_enter(rw, file, line)
16 eMrwlock_t *rw;
17 char *file;
18 int 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 
eMrwlock_write_enter(rw,file,line)37 void eMrwlock_write_enter(rw, file, line)
38 eMrwlock_t *rw;
39 char *file;
40 int 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 
eMrwlock_downgrade(rw,file,line)59 void eMrwlock_downgrade(rw, file, line)
60 eMrwlock_t *rw;
61 char *file;
62 int 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 
eMrwlock_exit(rw)82 void eMrwlock_exit(rw)
83 eMrwlock_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 
eMrwlock_init(rw,who)104 void eMrwlock_init(rw, who)
105 eMrwlock_t *rw;
106 char *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 
eMrwlock_destroy(rw)124 void eMrwlock_destroy(rw)
125 eMrwlock_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