Home | History | Annotate | Download | only in jni 
      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 #include <string.h>
     27 
     28 /*******************************************************************************
     29 **
     30 ** Function:        Mutex
     31 **
     32 ** Description:     Initialize member variables.
     33 **
     34 ** Returns:         None.
     35 **
     36 *******************************************************************************/
     37 Mutex::Mutex ()
     38 {
     39     memset (&mMutex, 0, sizeof(mMutex));
     40     int res = pthread_mutex_init (&mMutex, NULL);
     41     if (res != 0)
     42     {
     43         ALOGE ("Mutex::Mutex: fail init; error=0x%X", res);
     44     }
     45 }
     46 
     47 
     48 /*******************************************************************************
     49 **
     50 ** Function:        ~Mutex
     51 **
     52 ** Description:     Cleanup all resources.
     53 **
     54 ** Returns:         None.
     55 **
     56 *******************************************************************************/
     57 Mutex::~Mutex ()
     58 {
     59     int res = pthread_mutex_destroy (&mMutex);
     60     if (res != 0)
     61     {
     62         ALOGE ("Mutex::~Mutex: fail destroy; error=0x%X", res);
     63     }
     64 }
     65 
     66 
     67 /*******************************************************************************
     68 **
     69 ** Function:        lock
     70 **
     71 ** Description:     Block the thread and try lock the mutex.
     72 **
     73 ** Returns:         None.
     74 **
     75 *******************************************************************************/
     76 void Mutex::lock ()
     77 {
     78     int res = pthread_mutex_lock (&mMutex);
     79     if (res != 0)
     80     {
     81         ALOGE ("Mutex::lock: fail lock; error=0x%X", res);
     82     }
     83 }
     84 
     85 
     86 /*******************************************************************************
     87 **
     88 ** Function:        unlock
     89 **
     90 ** Description:     Unlock a mutex to unblock a thread.
     91 **
     92 ** Returns:         None.
     93 **
     94 *******************************************************************************/
     95 void Mutex::unlock ()
     96 {
     97     int res = pthread_mutex_unlock (&mMutex);
     98     if (res != 0)
     99     {
    100         ALOGE ("Mutex::unlock: fail unlock; error=0x%X", res);
    101     }
    102 }
    103 
    104 
    105 /*******************************************************************************
    106 **
    107 ** Function:        tryLock
    108 **
    109 ** Description:     Try to lock the mutex.
    110 **
    111 ** Returns:         True if the mutex is locked.
    112 **
    113 *******************************************************************************/
    114 bool Mutex::tryLock ()
    115 {
    116     int res = pthread_mutex_trylock (&mMutex);
    117     if ((res != 0) && (res != EBUSY))
    118     {
    119         ALOGE ("Mutex::tryLock: error=0x%X", res);
    120     }
    121     return res == 0;
    122 }
    123 
    124 
    125 /*******************************************************************************
    126 **
    127 ** Function:        nativeHandle
    128 **
    129 ** Description:     Get the handle of the mutex.
    130 **
    131 ** Returns:         Handle of the mutex.
    132 **
    133 *******************************************************************************/
    134 pthread_mutex_t* Mutex::nativeHandle ()
    135 {
    136     return &mMutex;
    137 }
    138 
    139 
    140