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
|
/*
Copyright (C) 2010 Zimin
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#include <config.h>
#include <pthread.h>
#include <assert.h>
#include "filesystemlock.h"
FilesystemLock::FilesystemLock()
: scanner_count(0),
updater_count(0)
{
pthread_cond_init(&condition, NULL);
pthread_mutex_init(&mutex, NULL);
}
FilesystemLock::~FilesystemLock()
{
pthread_cond_destroy(&condition);
pthread_mutex_destroy(&mutex);
}
void FilesystemLock::scan_begin()
{
pthread_mutex_lock(&mutex);
while (true)
{
if (updater_count == 0)
{
scanner_count++;
pthread_mutex_unlock(&mutex);
return;
}
pthread_cond_wait(&condition, &mutex);
}
}
void FilesystemLock::scan_end() {
pthread_mutex_lock(&mutex);
scanner_count--;
assert(scanner_count >= 0);
if (scanner_count == 0)
pthread_cond_broadcast(&condition);
pthread_mutex_unlock(&mutex);
}
void FilesystemLock::scan_update_begin()
{
pthread_mutex_lock(&mutex);
while (true)
{
if (scanner_count == 0 && updater_count == 0)
{
scanner_count++;
updater_count++;
pthread_mutex_unlock(&mutex);
return;
}
pthread_cond_wait(&condition, &mutex);
}
}
void FilesystemLock::scan_update_end()
{
pthread_mutex_lock(&mutex);
scanner_count--;
updater_count--;
assert(scanner_count >= 0 && updater_count >= 0);
pthread_cond_broadcast(&condition);
pthread_mutex_unlock(&mutex);
}
|