1 /*
2 * Copyright (C) 2012 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 /*
18 * Encapsulate a mutex for thread synchronization.
19 */
20
21 #include "Mutex.h"
22 #include "NfcJniUtil.h"
23
24 #include <cutils/log.h>
25 #include <errno.h>
26
27 /*******************************************************************************
28 **
29 ** Function: Mutex
30 **
31 ** Description: Initialize member variables.
32 **
33 ** Returns: None.
34 **
35 *******************************************************************************/
Mutex()36 Mutex::Mutex ()
37 {
38 memset (&mMutex, 0, sizeof(mMutex));
39 int res = pthread_mutex_init (&mMutex, NULL);
40 if (res != 0)
41 {
42 ALOGE ("Mutex::Mutex: fail init; error=0x%X", res);
43 }
44 }
45
46
47 /*******************************************************************************
48 **
49 ** Function: ~Mutex
50 **
51 ** Description: Cleanup all resources.
52 **
53 ** Returns: None.
54 **
55 *******************************************************************************/
~Mutex()56 Mutex::~Mutex ()
57 {
58 int res = pthread_mutex_destroy (&mMutex);
59 if (res != 0)
60 {
61 ALOGE ("Mutex::~Mutex: fail destroy; error=0x%X", res);
62 }
63 }
64
65
66 /*******************************************************************************
67 **
68 ** Function: lock
69 **
70 ** Description: Block the thread and try lock the mutex.
71 **
72 ** Returns: None.
73 **
74 *******************************************************************************/
lock()75 void Mutex::lock ()
76 {
77 int res = pthread_mutex_lock (&mMutex);
78 if (res != 0)
79 {
80 ALOGE ("Mutex::lock: fail lock; error=0x%X", res);
81 }
82 }
83
84
85 /*******************************************************************************
86 **
87 ** Function: unlock
88 **
89 ** Description: Unlock a mutex to unblock a thread.
90 **
91 ** Returns: None.
92 **
93 *******************************************************************************/
unlock()94 void Mutex::unlock ()
95 {
96 int res = pthread_mutex_unlock (&mMutex);
97 if (res != 0)
98 {
99 ALOGE ("Mutex::unlock: fail unlock; error=0x%X", res);
100 }
101 }
102
103
104 /*******************************************************************************
105 **
106 ** Function: tryLock
107 **
108 ** Description: Try to lock the mutex.
109 **
110 ** Returns: True if the mutex is locked.
111 **
112 *******************************************************************************/
tryLock()113 bool Mutex::tryLock ()
114 {
115 int res = pthread_mutex_trylock (&mMutex);
116 if ((res != 0) && (res != EBUSY))
117 {
118 ALOGE ("Mutex::tryLock: error=0x%X", res);
119 }
120 return res == 0;
121 }
122
123
124 /*******************************************************************************
125 **
126 ** Function: nativeHandle
127 **
128 ** Description: Get the handle of the mutex.
129 **
130 ** Returns: Handle of the mutex.
131 **
132 *******************************************************************************/
nativeHandle()133 pthread_mutex_t* Mutex::nativeHandle ()
134 {
135 return &mMutex;
136 }
137
138
139