xref: /freebsd/sbin/ipf/libipf/rwlock_emul.c (revision 4731124cace5e7a0224e29784617d2856e5c59ab)
1 /*	$FreeBSD$	*/
2 
3 /*
4  * Copyright (C) 2012 by Darren Reed.
5  *
6  * See the IPFILTER.LICENCE file for details on licencing.
7  *
8  * $Id$
9  */
10 
11 #include "ipf.h"
12 
13 #define	EMM_MAGIC	0x97dd8b3a
14 
15 void eMrwlock_read_enter(eMrwlock_t *rw, char *file, int line)
16 {
17 	if (rw->eMrw_magic != EMM_MAGIC) {
18 		fprintf(stderr, "%s:eMrwlock_read_enter(%p): bad magic: %#x\n",
19 			rw->eMrw_owner, rw, rw->eMrw_magic);
20 		abort();
21 	}
22 	if (rw->eMrw_read != 0 || rw->eMrw_write != 0) {
23 		fprintf(stderr,
24 			"%s:eMrwlock_read_enter(%p): already locked: %d/%d\n",
25 			rw->eMrw_owner, rw, rw->eMrw_read, rw->eMrw_write);
26 		abort();
27 	}
28 	rw->eMrw_read++;
29 	rw->eMrw_heldin = file;
30 	rw->eMrw_heldat = line;
31 }
32 
33 
34 void eMrwlock_write_enter(eMrwlock_t *rw, char *file, int line)
35 {
36 	if (rw->eMrw_magic != EMM_MAGIC) {
37 		fprintf(stderr, "%s:eMrwlock_write_enter(%p): bad magic: %#x\n",
38 			rw->eMrw_owner, rw, rw->eMrw_magic);
39 		abort();
40 	}
41 	if (rw->eMrw_read != 0 || rw->eMrw_write != 0) {
42 		fprintf(stderr,
43 			"%s:eMrwlock_write_enter(%p): already locked: %d/%d\n",
44 			rw->eMrw_owner, rw, rw->eMrw_read, rw->eMrw_write);
45 		abort();
46 	}
47 	rw->eMrw_write++;
48 	rw->eMrw_heldin = file;
49 	rw->eMrw_heldat = line;
50 }
51 
52 
53 void eMrwlock_try_upgrade(eMrwlock_t *rw, char *file, int line)
54 {
55 	if (rw->eMrw_magic != EMM_MAGIC) {
56 		fprintf(stderr, "%s:eMrwlock_write_enter(%p): bad magic: %#x\n",
57 			rw->eMrw_owner, rw, rw->eMrw_magic);
58 		abort();
59 	}
60 	if (rw->eMrw_read != 0 || rw->eMrw_write != 0) {
61 		fprintf(stderr,
62 			"%s:eMrwlock_try_upgrade(%p): already locked: %d/%d\n",
63 			rw->eMrw_owner, rw, rw->eMrw_read, rw->eMrw_write);
64 		abort();
65 	}
66 	rw->eMrw_write++;
67 	rw->eMrw_heldin = file;
68 	rw->eMrw_heldat = line;
69 }
70 
71 void eMrwlock_downgrade(eMrwlock_t *rw, char *file, int line)
72 {
73 	if (rw->eMrw_magic != EMM_MAGIC) {
74 		fprintf(stderr, "%s:eMrwlock_write_enter(%p): bad magic: %#x\n",
75 			rw->eMrw_owner, rw, rw->eMrw_magic);
76 		abort();
77 	}
78 	if (rw->eMrw_read != 0 || rw->eMrw_write != 1) {
79 		fprintf(stderr,
80 			"%s:eMrwlock_write_enter(%p): already locked: %d/%d\n",
81 			rw->eMrw_owner, rw, rw->eMrw_read, rw->eMrw_write);
82 		abort();
83 	}
84 	rw->eMrw_write--;
85 	rw->eMrw_read++;
86 	rw->eMrw_heldin = file;
87 	rw->eMrw_heldat = line;
88 }
89 
90 
91 void eMrwlock_exit(eMrwlock_t *rw)
92 {
93 	if (rw->eMrw_magic != EMM_MAGIC) {
94 		fprintf(stderr, "%s:eMrwlock_exit(%p): bad magic: %#x\n",
95 			rw->eMrw_owner, rw, rw->eMrw_magic);
96 		abort();
97 	}
98 	if (rw->eMrw_read != 1 && rw->eMrw_write != 1) {
99 		fprintf(stderr, "%s:eMrwlock_exit(%p): not locked: %d/%d\n",
100 			rw->eMrw_owner, rw, rw->eMrw_read, rw->eMrw_write);
101 		abort();
102 	}
103 	if (rw->eMrw_read == 1)
104 		rw->eMrw_read--;
105 	else if (rw->eMrw_write == 1)
106 		rw->eMrw_write--;
107 	rw->eMrw_heldin = NULL;
108 	rw->eMrw_heldat = 0;
109 }
110 
111 
112 static int initcount = 0;
113 
114 void eMrwlock_init(eMrwlock_t *rw, char *who)
115 {
116 	if (rw->eMrw_magic == EMM_MAGIC) {	/* safe bet ? */
117 		fprintf(stderr,
118 			"%s:eMrwlock_init(%p): already initialised?: %#x\n",
119 			rw->eMrw_owner, rw, rw->eMrw_magic);
120 		abort();
121 	}
122 	rw->eMrw_magic = EMM_MAGIC;
123 	rw->eMrw_read = 0;
124 	rw->eMrw_write = 0;
125 	if (who != NULL)
126 		rw->eMrw_owner = strdup(who);
127 	else
128 		rw->eMrw_owner = NULL;
129 	initcount++;
130 }
131 
132 
133 void eMrwlock_destroy(eMrwlock_t *rw)
134 {
135 	if (rw->eMrw_magic != EMM_MAGIC) {
136 		fprintf(stderr, "%s:eMrwlock_destroy(%p): bad magic: %#x\n",
137 			rw->eMrw_owner, rw, rw->eMrw_magic);
138 		abort();
139 	}
140 	if (rw->eMrw_owner != NULL)
141 		free(rw->eMrw_owner);
142 	memset(rw, 0xa5, sizeof(*rw));
143 	initcount--;
144 }
145 
146 void ipf_rwlock_clean(void)
147 {
148 	if (initcount != 0)
149 		abort();
150 }
151