Java example source code file (PopAndStepTest.java)

This example Java source code file (PopAndStepTest.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

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Java - Java tags/keywords

exception, fail, got, iterator, jdi, popandsteptarg, popandsteptest, referencetype, should, stackframe, stepping, string, this, util

The PopAndStepTest.java Java example source code

/* /nodynamiccopyright/ */  // DO NOT DELETE ANY LINES!!!!
//    THIS TEST IS LINE NUMBER SENSITIVE
/**
 *  @test
 *  @bug 4530424
 *  @summary Hin says that doing a step over after a popframe acts like a resume.
 *
 *  @author jjh
 *
 *  @library ..
 *  @run build TestScaffold VMConnection TargetListener TargetAdapter
 *  @run compile -g PopAndStepTest.java
 *  @run main PopAndStepTest
 */
import com.sun.jdi.*;
import com.sun.jdi.event.*;
import com.sun.jdi.request.*;

import java.util.*;

    /********** LINE NUMBER SENSITIVE! *****************************************************************/

class PopAndStepTarg {
    public void B() {
        System.out.println("debuggee: in B");
        System.out.println("debuggee: in B, back to A");   // add line breakpoint here line 26 !!!
    }

    public void A() {
        System.out.println("debuggee: in A, about to call B");  // line 30
        B();
        System.out.println("debuggee: in A, back from B");      // line 32
        throw new RuntimeException("debuggee: Got to line 33");
    }

    public static void main(String[] args) {
        System.out.println("debuggee: Howdy!");      // line 37
        PopAndStepTarg xxx = new PopAndStepTarg();   // line 39
        xxx.A();                                     // line 40
        System.out.println("debugee: Goodbye from PopAndStepTarg!");
    }
}


    /********** test program **********/

public class PopAndStepTest extends TestScaffold {
    ReferenceType targetClass;
    ThreadReference mainThread;

    PopAndStepTest (String args[]) {
        super(args);
    }

    public static void main(String[] args)      throws Exception {
        new PopAndStepTest(args).startTests();
    }


    StackFrame frameFor(String methodName) throws Exception {
        Iterator it = mainThread.frames().iterator();

        while (it.hasNext()) {
            StackFrame frame = (StackFrame)it.next();
            if (frame.location().method().name().equals(methodName)) {
                return frame;
            }
        }
        failure("FAIL: " + methodName + " not on stack");
        return null;
    }

    int getDebuggeeLineNum(int expectedLine) throws Exception {
        List allFrames = mainThread.frames();
        if ( allFrames == null) {
            return -1;
        }
        Iterator it = allFrames.iterator();
        StackFrame frame = (StackFrame)it.next();
        Location loc = frame.location();
        int theLine = loc.lineNumber();
        if (expectedLine != theLine) {
            failure("FAIL: Should be at " + expectedLine + ", are at " +
                    theLine + ", method = " + loc.method().name());
        } else {
            println("Should be at, and am at: " + expectedLine);
        }
        return theLine;
    }


    public void vmDied(VMDeathEvent event) {
        println("Got VMDeathEvent");
    }

    public void vmDisconnected(VMDisconnectEvent event) {
        println("Got VMDisconnectEvent");
    }

    /********** test core **********/

    protected void runTests() throws Exception {
        /*
         * Get to the top of main()
         * to determine targetClass and mainThread
         */
        runOnce();
    }

    void runOnce() throws Exception{
        /*
         * Get to the top of main()
         * to determine targetClass and mainThread
         */
        BreakpointEvent bpe = startToMain("PopAndStepTarg");
        targetClass = bpe.location().declaringType();
        mainThread = bpe.thread();
        getDebuggeeLineNum(37);

        println("Resuming to line 26");
        bpe = resumeTo("PopAndStepTarg", 26); getDebuggeeLineNum(26);

        // The failure is this:
        //   create step request
        //   enable step request
        //   pop frame
        //   do the step
        //   do another step - This step runs to completion
        EventRequestManager erm = eventRequestManager();
        StepRequest srInto = erm.createStepRequest(mainThread, StepRequest.STEP_LINE,
                                                   StepRequest.STEP_INTO);
        srInto.addClassExclusionFilter("java.*");
        srInto.addClassExclusionFilter("javax.*");
        srInto.addClassExclusionFilter("sun.*");
        srInto.addClassExclusionFilter("com.sun.*");
        srInto.addClassExclusionFilter("com.oracle.*");
        srInto.addClassExclusionFilter("oracle.*");
        srInto.addClassExclusionFilter("jdk.internal.*");
        srInto.addCountFilter(1);
        srInto.enable(); // This fails
        mainThread.popFrames(frameFor("A"));
        //srInto.enable();   // if the enable is moved here, it passes
        println("Popped back to line 40 in main, the call to A()");
        println("Stepping into line 30");
        waitForRequestedEvent(srInto);   // println
        srInto.disable();

        getDebuggeeLineNum(30);

        // The failure occurs here.
        println("Stepping over to line 31");
        stepOverLine(mainThread);   // println
        getDebuggeeLineNum(31);

        println("Stepping over to line 32");
        stepOverLine(mainThread);        // call to B()
        getDebuggeeLineNum(32);

        vm().exit(0);

        if (testFailed) {
            throw new Exception("PopAndStepTest failed");
        }
        println("Passed:");
    }
}