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MONITORENTER.java

package gov.nasa.arc.ase.jpf.jvm.bytecode;

import gov.nasa.arc.ase.jpf.*;
import gov.nasa.arc.ase.jpf.jvm.*;
import de.fub.bytecode.generic.InstructionHandle;
import gov.nasa.arc.ase.util.Debug;

public class MONITORENTER extends AbstractInstruction {
  private de.fub.bytecode.generic.MONITORENTER peer;

  public InstructionHandle execute(SystemState ss, KernelState ks, ThreadInfo th) {
    // gets the object reference (without removing it from the stack)
    int objref = th.peek();

    if (ks.dynamic_area.monitorLock(objref, th)) {
      // now you can remove it from the stack
      th.pop();

      return th.getPC().getNext();
    } else {
      throw new InternalErrorException("can't get into the monitor");
    }
  }  
  public boolean isExecutable(SystemState ss, KernelState ks, ThreadInfo th) {
    // gets the object reference (without removing it from the stack)
    int objref = th.peek();

    return ks.dynamic_area.monitorCheckLock(objref, th);
  }  
  public void setPeer(de.fub.bytecode.generic.Instruction i) {
    peer = (de.fub.bytecode.generic.MONITORENTER)i;
  }  
}

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