//
// Copyright (C) 2006 United States Government as represented by the
// Administrator of the National Aeronautics and Space Administration
// (NASA). All Rights Reserved.
//
// This software is distributed under the NASA Open Source Agreement
// (NOSA), version 1.3. The NOSA has been approved by the Open Source
// Initiative. See the file NOSA-1.3-JPF at the top of the distribution
// directory tree for the complete NOSA document.
//
// THE SUBJECT SOFTWARE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY OF ANY
// KIND, EITHER EXPRESSED, IMPLIED, OR STATUTORY, INCLUDING, BUT NOT
// LIMITED TO, ANY WARRANTY THAT THE SUBJECT SOFTWARE WILL CONFORM TO
// SPECIFICATIONS, ANY IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR
// A PARTICULAR PURPOSE, OR FREEDOM FROM INFRINGEMENT, ANY WARRANTY THAT
// THE SUBJECT SOFTWARE WILL BE ERROR FREE, OR ANY WARRANTY THAT
// DOCUMENTATION, IF PROVIDED, WILL CONFORM TO THE SUBJECT SOFTWARE.
//
package gov.nasa.jpf.jvm.bytecode;
import java.util.function.BiFunction;
import cmu.conditional.Conditional;
import cmu.conditional.One;
import de.fosd.typechef.featureexpr.FeatureExpr;
import gov.nasa.jpf.vm.ChoiceGenerator;
import gov.nasa.jpf.vm.ElementInfo;
import gov.nasa.jpf.vm.Instruction;
import gov.nasa.jpf.vm.MJIEnv;
import gov.nasa.jpf.vm.StackFrame;
import gov.nasa.jpf.vm.ThreadInfo;
import gov.nasa.jpf.vm.VM;
/**
* Exit monitor for object
* ..., objectref => ...
*/
public class MONITOREXIT extends LockInstruction {
public Conditional<Instruction> execute(FeatureExpr ctx, final ThreadInfo ti) {
StackFrame frame = ti.getModifiableTopFrame();
Conditional<Integer> objref = frame.peek(ctx);
final MONITOREXIT thisInstruction = this;
return objref.mapf(ctx, new BiFunction<FeatureExpr, Integer, Conditional<Instruction>>() {
@Override
public Conditional<Instruction> apply(FeatureExpr ctx, Integer objref) {
if (objref == MJIEnv.NULL) {
return new One<>(ti.createAndThrowException(ctx, "java.lang.NullPointerException", "attempt to release lock for null object"));
}
lastLockRef = objref;
if (!ti.isFirstStepInsn()) {
ElementInfo ei = ti.getModifiableElementInfo(objref);
// we only do this in the bottom half, but before potentially creating
// a CG so that other threads that might become runnable are included
ei.unlock(ti); // might still be recursive
if (ei.getLockCount() == 0) { // this gave up the lock, check for CG
// this thread obviously has referenced the object before, but other
// referencers might have terminated so we want to update anyways
ei = ei.getInstanceWithUpdatedSharedness(ti);
if (ei.isShared()) {
VM vm = ti.getVM();
ChoiceGenerator<?> cg = vm.getSchedulerFactory().createMonitorExitCG(ei, ti);
if (cg != null) {
if (vm.setNextChoiceGenerator(cg)) {
return new One<Instruction>(thisInstruction);
}
}
}
}
}
StackFrame frame = ti.getModifiableTopFrame(); // now we need to modify it
frame.pop(ctx);
return getNext(ctx, ti);
}
});
}
public int getByteCode() {
return 0xC3;
}
public void accept(InstructionVisitor insVisitor) {
insVisitor.visit(this);
}
}