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 condition variable for thread synchronization.
19 */
20
21 #include "CondVar.h"
22 #include "NfcJniUtil.h"
23
24 #include <cutils/log.h>
25 #include <errno.h>
26
27
28 /*******************************************************************************
29 **
30 ** Function: CondVar
31 **
32 ** Description: Initialize member variables.
33 **
34 ** Returns: None.
35 **
36 *******************************************************************************/
CondVar()37 CondVar::CondVar ()
38 {
39 pthread_condattr_t attr;
40 pthread_condattr_init(&attr);
41 pthread_condattr_setclock(&attr, CLOCK_MONOTONIC);
42 memset (&mCondition, 0, sizeof(mCondition));
43 int const res = pthread_cond_init (&mCondition, &attr);
44 if (res)
45 {
46 ALOGE ("CondVar::CondVar: fail init; error=0x%X", res);
47 }
48 }
49
50
51 /*******************************************************************************
52 **
53 ** Function: ~CondVar
54 **
55 ** Description: Cleanup all resources.
56 **
57 ** Returns: None.
58 **
59 *******************************************************************************/
~CondVar()60 CondVar::~CondVar ()
61 {
62 int const res = pthread_cond_destroy (&mCondition);
63 if (res)
64 {
65 ALOGE ("CondVar::~CondVar: fail destroy; error=0x%X", res);
66 }
67 }
68
69
70 /*******************************************************************************
71 **
72 ** Function: wait
73 **
74 ** Description: Block the caller and wait for a condition.
75 **
76 ** Returns: None.
77 **
78 *******************************************************************************/
wait(Mutex & mutex)79 void CondVar::wait (Mutex& mutex)
80 {
81 int const res = pthread_cond_wait (&mCondition, mutex.nativeHandle());
82 if (res)
83 {
84 ALOGE ("CondVar::wait: fail wait; error=0x%X", res);
85 }
86 }
87
88
89 /*******************************************************************************
90 **
91 ** Function: wait
92 **
93 ** Description: Block the caller and wait for a condition.
94 ** millisec: Timeout in milliseconds.
95 **
96 ** Returns: True if wait is successful; false if timeout occurs.
97 **
98 *******************************************************************************/
wait(Mutex & mutex,long millisec)99 bool CondVar::wait (Mutex& mutex, long millisec)
100 {
101 bool retVal = false;
102 struct timespec absoluteTime;
103
104 if (clock_gettime (CLOCK_MONOTONIC, &absoluteTime) == -1)
105 {
106 ALOGE ("CondVar::wait: fail get time; errno=0x%X", errno);
107 }
108 else
109 {
110 absoluteTime.tv_sec += millisec / 1000;
111 long ns = absoluteTime.tv_nsec + ((millisec % 1000) * 1000000);
112 if (ns > 1000000000)
113 {
114 absoluteTime.tv_sec++;
115 absoluteTime.tv_nsec = ns - 1000000000;
116 }
117 else
118 absoluteTime.tv_nsec = ns;
119 }
120
121 int waitResult = pthread_cond_timedwait (&mCondition, mutex.nativeHandle(), &absoluteTime);
122 if ((waitResult != 0) && (waitResult != ETIMEDOUT))
123 ALOGE ("CondVar::wait: fail timed wait; error=0x%X", waitResult);
124 retVal = (waitResult == 0); //waited successfully
125 return retVal;
126 }
127
128
129 /*******************************************************************************
130 **
131 ** Function: notifyOne
132 **
133 ** Description: Unblock the waiting thread.
134 **
135 ** Returns: None.
136 **
137 *******************************************************************************/
notifyOne()138 void CondVar::notifyOne ()
139 {
140 int const res = pthread_cond_signal (&mCondition);
141 if (res)
142 {
143 ALOGE ("CondVar::notifyOne: fail signal; error=0x%X", res);
144 }
145 }
146
147