/*

* Copyright (c) 1994, 2012, Oracle and/or its affiliates. All rights reserved.

* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

*

* This code is free software; you can redistribute it and/or modify it

* under the terms of the GNU General Public License version 2 only, as

* published by the Free Software Foundation. Oracle designates this

* particular file as subject to the "Classpath" exception as provided

* by Oracle in the LICENSE file that accompanied this code.

*

* This code is distributed in the hope that it will be useful, but WITHOUT

* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License

* version 2 for more details (a copy is included in the LICENSE file that

* accompanied this code).

*

* You should have received a copy of the GNU General Public License version

* 2 along with this work; if not, write to the Free Software Foundation,

* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

*

* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

* or visit www.oracle.com if you need additional information or have any

* questions.

*/

package java.lang;

import org.cprover.CProver;

import java.lang.NullPointerException;

import java.lang.IllegalMonitorStateException;

public class Object {

// lock needed for synchronization in JBMC

// used by monitorenter, monitorexit, wait, and notify

// Not present in the original Object class

public int cproverMonitorCount;

public Object() {

cproverMonitorCount = 0;

}

/**

* @diffblue.limitedSupport

* This relies on Class.forName whose model is only partial. The model of

* Class is made to work for combinations of calls to Object.getClass,

* Class.forName and Class.getName but other operations are unlikely to

* work.

*/

public final Class<?> getClass() {

// DIFFBLUE MODEL LIBRARY

return Class.forName(CProver.classIdentifier(this));

}

public int hashCode() {

return 0;

}

public boolean equals(Object obj) {

return (this == obj);

}

protected Object clone() throws CloneNotSupportedException {

throw new CloneNotSupportedException();

}

public String toString() {

return getClass().getName() + "@" + Integer.toHexString(hashCode());

}

public final void notify() {

// TODO: the thread must own the lock when it calls notify

}

public final void notifyAll() {

// TODO: the thread must own the lock when it calls notifyAll

}

public final void wait(long timeout) throws InterruptedException {

// TODO: the thread must own the lock when it calls wait

// should only throw if the interrupted flag in Thread is enabled

throw new InterruptedException();

}

public final void wait(long timeout, int nanos) throws InterruptedException {

if (timeout < 0) {

throw new IllegalArgumentException("timeout value is negative");

}

if (nanos < 0 || nanos > 999999) {

throw new IllegalArgumentException(

"nanosecond timeout value out of range");

}

if (nanos > 0) {

timeout++;

}

wait(timeout);

}

public final void wait() throws InterruptedException {

wait(0);

}

protected void finalize() throws Throwable { }

/**

* This method is not present in the original Object class.

* It will be called by JBMC when the monitor in this instance

* is being acquired as a result of either the execution of a

* monitorenter bytecode instruction or the call to a synchronized

* method. It uses a counter to enable reentrance and an atomic section

* to ensure multiple threads do not race in the access/modification of

* the counter.

*/

public static void monitorenter(Object object)

{

// TODO: we shoud remove the call to this method from the call

// stack appended to the thrown exception

if (object == null)

throw new NullPointerException();

CProver.atomicBegin();

// this assume blocks this execution path in JBMC and simulates

// the thread having to wait because the monitor is not available

CProver.assume(object.cproverMonitorCount == 0);

object.cproverMonitorCount++;

CProver.atomicEnd();

}

/**

* This method is not present in the original Object class.

* It will be called by JBMC when the monitor in this instance

* is being released as a result of either the execution of a

* monitorexit bytecode instruction or the return (normal or exceptional)

* of a synchronized method. It decrements the cproverMonitorCount that

* had been incremented in monitorenter().

*/

public static void monitorexit(Object object)

{

// TODO: we shoud remove the call to this method from the call

// stack appended to the thrown exception

// TODO: Enabling these exceptions makes

// jbmc/synchronized-blocks/test_sync.desc

// run into an infinite loop during symex

// if (object == null)

// throw new NullPointerException();

// if (object.cproverMonitorCount == 0)

// throw new IllegalMonitorStateException();

CProver.atomicBegin();

object.cproverMonitorCount--;

CProver.atomicEnd();

}

}