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/*
* Copyright (C) 2015 The Team Win Recovery Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <pthread.h>
#include <stdio.h>
#include "tw_atomic.hpp"
/*
* According to this documentation:
* https://developer.android.com/training/articles/smp.html
* it is recommended to use mutexes instead of atomics. This class
* provides us with a wrapper to make "atomic" variables easy to use.
*/
TWAtomicInt::TWAtomicInt(int initial_value /* = 0 */) {
if (pthread_mutex_init(&mutex_lock, NULL) != 0) {
// This should hopefully never happen. If it does, the
// operations will not be atomic, but we will allow things to
// continue anyway after logging the issue and just hope for
// the best.
printf("TWAtomic error initializing mutex.\n");
use_mutex = false;
} else {
use_mutex = true;
}
value = initial_value;
}
TWAtomicInt::~TWAtomicInt() {
if (use_mutex)
pthread_mutex_destroy(&mutex_lock);
}
void TWAtomicInt::set_value(int new_value) {
if (use_mutex) {
pthread_mutex_lock(&mutex_lock);
value = new_value;
pthread_mutex_unlock(&mutex_lock);
} else {
value = new_value;
}
}
int TWAtomicInt::get_value(void) {
int ret_val;
if (use_mutex) {
pthread_mutex_lock(&mutex_lock);
ret_val = value;
pthread_mutex_unlock(&mutex_lock);
} else {
ret_val = value;
}
return ret_val;
}
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