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/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2008 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*
* Copyright 2019 RackTop Systems.
*/
#include "Lockable.h"
#include <iostream>
#include <cstdio>
#include <cerrno>
#include <unistd.h>
#include <cstring>
using namespace std;
#define DEADLOCK_WARNING 10
#define LOCK_SLEEP 1
/**
* @memo Create a lockable instance and initialize internal locks
*/
Lockable::Lockable() {
if (pthread_mutex_init(&mutex, NULL)) {
}
}
/**
* @memo Free up a lockable instance
*/
Lockable::~Lockable() {
if (pthread_mutex_destroy(&mutex)) {
}
}
/**
* @memo Unlock the instance
* @precondition This thread must have locked the instance
* @postcondition The instance will be unlocked
*/
void Lockable::unlock() {
unlock(&mutex);
}
/**
* @memo Unlock a given mutex lock
* @precondition The lock must be held by this thread
* @postcondition The lock will be released
* @param myMutex The lock to unlock
*/
void Lockable::unlock(pthread_mutex_t *myMutex) {
pthread_mutex_unlock(myMutex);
}
/**
* @memo Lock the instance
* @postcondition The lock will be held by this thread.
*/
void Lockable::lock() {
lock(&mutex);
}
/**
* @memo Lock the given mutex lock
* @postcondition The lock will be held by this thread
* @param myMutex The mutex lock to take
*/
void Lockable::lock(pthread_mutex_t *myMutex) {
int status;
int loop = 0;
do {
loop++;
status = pthread_mutex_trylock(myMutex);
if (status) {
switch (pthread_mutex_trylock(myMutex)) {
case EFAULT:
cerr << "Lock failed: Fault" << endl;
break;
case EINVAL:
cerr << "Lock failed: Invalid" << endl;
break;
case EBUSY:
if (loop > DEADLOCK_WARNING) {
cerr << "Lock failed: Deadlock" << endl;
}
break;
case EOWNERDEAD:
cerr << "Lock failed: Owner died" << endl;
break;
case ELOCKUNMAPPED:
cerr << "Lock failed: Unmapped" << endl;
break;
case ENOTRECOVERABLE:
cerr << "Lock failed: not recoverable" << endl;
/* FALLTHROUGH */
default:
if (loop > DEADLOCK_WARNING) {
cerr << "Lock failed: " <<strerror(status) << endl;
break;
}
}
} else {
break; // Lock taken succesfully
}
sleep(LOCK_SLEEP);
} while (status);
}
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