1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
|
/*-
* Copyright (c) 2006, Maxime Henrion <mux@FreeBSD.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#include <assert.h>
#include <pthread.h>
#include <stdlib.h>
#include <string.h>
#include "fixups.h"
#include "misc.h"
#include "queue.h"
/*
* A synchronized queue to implement fixups. The updater thread adds
* fixup requests to the queue with fixups_put() when a checksum
* mismatch error occured. It then calls fixups_close() when he's
* done requesting fixups. The detailer thread gets the fixups with
* fixups_get() and then send the requests to the server.
*
* The queue is synchronized with a mutex and a condition variable.
*/
struct fixups {
pthread_mutex_t lock;
pthread_cond_t cond;
STAILQ_HEAD(, fixup) fixupq;
struct fixup *cur;
size_t size;
int closed;
};
static void fixups_lock(struct fixups *);
static void fixups_unlock(struct fixups *);
static struct fixup *fixup_new(struct coll *, const char *);
static void fixup_free(struct fixup *);
static void
fixups_lock(struct fixups *f)
{
int error;
error = pthread_mutex_lock(&f->lock);
assert(!error);
}
static void
fixups_unlock(struct fixups *f)
{
int error;
error = pthread_mutex_unlock(&f->lock);
assert(!error);
}
static struct fixup *
fixup_new(struct coll *coll, const char *name)
{
struct fixup *fixup;
fixup = xmalloc(sizeof(struct fixup));
fixup->f_name = xstrdup(name);
fixup->f_coll = coll;
return (fixup);
}
static void
fixup_free(struct fixup *fixup)
{
free(fixup->f_name);
free(fixup);
}
/* Create a new fixup queue. */
struct fixups *
fixups_new(void)
{
struct fixups *f;
f = xmalloc(sizeof(struct fixups));
f->size = 0;
f->closed = 0;
f->cur = NULL;
STAILQ_INIT(&f->fixupq);
pthread_mutex_init(&f->lock, NULL);
pthread_cond_init(&f->cond, NULL);
return (f);
}
/* Add a fixup request to the queue. */
void
fixups_put(struct fixups *f, struct coll *coll, const char *name)
{
struct fixup *fixup;
int dosignal;
dosignal = 0;
fixup = fixup_new(coll, name);
fixups_lock(f);
assert(!f->closed);
STAILQ_INSERT_TAIL(&f->fixupq, fixup, f_link);
if (f->size++ == 0)
dosignal = 1;
fixups_unlock(f);
if (dosignal)
pthread_cond_signal(&f->cond);
}
/* Get a fixup request from the queue. */
struct fixup *
fixups_get(struct fixups *f)
{
struct fixup *fixup, *tofree;
fixups_lock(f);
while (f->size == 0 && !f->closed)
pthread_cond_wait(&f->cond, &f->lock);
if (f->closed && f->size == 0) {
fixups_unlock(f);
return (NULL);
}
assert(f->size > 0);
fixup = STAILQ_FIRST(&f->fixupq);
tofree = f->cur;
f->cur = fixup;
STAILQ_REMOVE_HEAD(&f->fixupq, f_link);
f->size--;
fixups_unlock(f);
if (tofree != NULL)
fixup_free(tofree);
return (fixup);
}
/* Close the writing end of the queue. */
void
fixups_close(struct fixups *f)
{
int dosignal;
dosignal = 0;
fixups_lock(f);
if (f->size == 0 && !f->closed)
dosignal = 1;
f->closed = 1;
fixups_unlock(f);
if (dosignal)
pthread_cond_signal(&f->cond);
}
/* Free a fixups queue. */
void
fixups_free(struct fixups *f)
{
struct fixup *fixup, *fixup2;
assert(f->closed);
/*
* Free any fixup that has been left on the queue.
* This can happen if we have been aborted prematurely.
*/
fixup = STAILQ_FIRST(&f->fixupq);
while (fixup != NULL) {
fixup2 = STAILQ_NEXT(fixup, f_link);
fixup_free(fixup);
fixup = fixup2;
}
if (f->cur != NULL)
fixup_free(f->cur);
pthread_cond_destroy(&f->cond);
pthread_mutex_destroy(&f->lock);
free(f);
}
|
