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
|
/*
* BSD LICENSE
*
* Copyright(c) 2022-2023 Intel Corporation. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * 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.
* * Neither the name of Intel Corporation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT
* OWNER 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.
*/
/**
* @brief Implementation of PQoS API lock
*
* provide functions for safe access to PQoS API - this is required for
* allocation and monitoring modules which also implement PQoS API
*/
#include "lock.h"
#include "log.h"
#include <fcntl.h> /* O_CREAT */
#include <pthread.h>
#include <sys/stat.h> /* S_Ixxx */
#include <unistd.h> /* usleep(), lockf() */
/**
* ---------------------------------------
* Local data structures
* ---------------------------------------
*/
/**
* API thread/process safe access is secured through these locks.
*/
static int m_apilock = -1;
static pthread_mutex_t m_apilock_mutex;
int
lock_init(void)
{
const char *lock_filename = LOCKFILE;
if (m_apilock != -1)
return -1;
m_apilock = open(lock_filename, O_WRONLY | O_CREAT,
S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
if (m_apilock == -1)
return -1;
if (pthread_mutex_init(&m_apilock_mutex, NULL) != 0) {
close(m_apilock);
m_apilock = -1;
return -1;
}
return 0;
}
int
lock_fini(void)
{
int ret = 0;
if (close(m_apilock) != 0)
ret = -1;
if (pthread_mutex_destroy(&m_apilock_mutex) != 0)
ret = -1;
m_apilock = -1;
return ret;
}
void
lock_get(void)
{
int err = 0;
if (lockf(m_apilock, F_LOCK, 0) != 0)
err = 1;
if (pthread_mutex_lock(&m_apilock_mutex) != 0)
err = 1;
if (err)
LOG_ERROR("API lock error!\n");
}
void
lock_release(void)
{
int err = 0;
if (lockf(m_apilock, F_ULOCK, 0) != 0)
err = 1;
if (pthread_mutex_unlock(&m_apilock_mutex) != 0)
err = 1;
if (err)
LOG_ERROR("API unlock error!\n");
}
|
