Java 类org.apache.bcel.generic.MONITORENTER 实例源码

public boolean preScreen(MethodGen mg) {
    ConstantPoolGen cpg = mg.getConstantPool();

    int lockCount = mg.isSynchronized() ? 1 : 0;
    boolean sawWaitOrNotify = false;

    InstructionHandle handle = mg.getInstructionList().getStart();
    while (handle != null && !(lockCount >= 2 && sawWaitOrNotify)) {
        Instruction ins = handle.getInstruction();
        if (ins instanceof MONITORENTER)
            ++lockCount;
        else if (ins instanceof INVOKEVIRTUAL) {
            INVOKEVIRTUAL inv = (INVOKEVIRTUAL) ins;
            String methodName = inv.getMethodName(cpg);
            if (methodName.equals("wait") || methodName.startsWith("notify"))
                sawWaitOrNotify = true;
        }

        handle = handle.getNext();
    }

    return lockCount >= 2 && sawWaitOrNotify;
}

public boolean preScreen(MethodGen mg) {
    ConstantPoolGen cpg = mg.getConstantPool();

    int lockCount = mg.isSynchronized() ? 1 : 0;
    boolean sawWaitOrNotify = false;

    InstructionHandle handle = mg.getInstructionList().getStart();
    while (handle != null && !(lockCount >= 2 && sawWaitOrNotify)) {
        Instruction ins = handle.getInstruction();
        if (ins instanceof MONITORENTER)
            ++lockCount;
        else if (ins instanceof INVOKEVIRTUAL) {
            INVOKEVIRTUAL inv = (INVOKEVIRTUAL) ins;
            String methodName = inv.getMethodName(cpg);
            if (methodName.equals("wait") || methodName.startsWith("notify"))
                sawWaitOrNotify = true;
        }

        handle = handle.getNext();
    }

    return lockCount >= 2 && sawWaitOrNotify;
}

public int getDelta(Instruction ins, ValueNumberFrame frame) throws DataflowAnalysisException {
    int delta = 0;

    if (ins instanceof MONITORENTER) {
        if (frame == null || !isThisValue(frame.getTopValue()))
            ++delta;
    } else if (ins instanceof MONITOREXIT) {
        if (frame == null || !isThisValue(frame.getTopValue()))
            --delta;
    }

    return delta;
}

public MatchResult match(InstructionHandle handle, ConstantPoolGen cpg,
                         ValueNumberFrame before, ValueNumberFrame after, BindingSet bindingSet) throws DataflowAnalysisException {

    // Instruction must be MONITORENTER.
    Instruction ins = handle.getInstruction();
    if (!(ins instanceof MONITORENTER))
        return null;

    // Ensure the object being locked matches any previous
    // instructions which bound our variable name to a value.
    Variable lock = new LocalVariable(before.getTopValue());
    return addOrCheckDefinition(lock, bindingSet);
}

public int getDelta(Instruction ins, ValueNumberFrame frame) throws DataflowAnalysisException {
    int delta = 0;
    if (ins instanceof MONITORENTER)
        ++delta;
    else if (ins instanceof MONITOREXIT)
        --delta;
    return delta;
}

/**
 * Scan a method for self call sites.
 * 
 * @param node
 *            the CallGraphNode for the method to be scanned
 */
private void scan(CallGraphNode node) throws CFGBuilderException {
    Method method = node.getMethod();
    CFG cfg = classContext.getCFG(method);

    if (method.isSynchronized())
        hasSynchronization = true;

    Iterator<BasicBlock> i = cfg.blockIterator();
    while (i.hasNext()) {
        BasicBlock block = i.next();
        Iterator<InstructionHandle> j = block.instructionIterator();
        while (j.hasNext()) {
            InstructionHandle handle = j.next();

            Instruction ins = handle.getInstruction();
            if (ins instanceof InvokeInstruction) {
                InvokeInstruction inv = (InvokeInstruction) ins;
                Method called = isSelfCall(inv);
                if (called != null) {
                    // Add edge to call graph
                    CallSite callSite = new CallSite(method, block, handle);
                    callGraph.createEdge(node, callGraph.getNodeForMethod(called), callSite);

                    // Add to called method set
                    calledMethodSet.add(called);
                }
            } else if (ins instanceof MONITORENTER || ins instanceof MONITOREXIT) {
                hasSynchronization = true;
            }
        }
    }
}

@Override
public void visitMONITORENTER(MONITORENTER obj) {
    // Don't know what this sync invocation is doing.
    // Kill all loads.
    ValueNumber topValue = null;
    try {
        topValue = getFrame().getStackValue(0);
    } catch (DataflowAnalysisException e) {
        AnalysisContext.logError("error handling monitor enter in value numbering", e);
    }
    getFrame().killAllLoadsExceptFor(topValue);
    handleNormalInstruction(obj);
}

@Override
public MatchResult match(InstructionHandle handle, ConstantPoolGen cpg, ValueNumberFrame before, ValueNumberFrame after,
        BindingSet bindingSet) throws DataflowAnalysisException {

    // Instruction must be MONITORENTER.
    Instruction ins = handle.getInstruction();
    if (!(ins instanceof MONITORENTER))
        return null;

    // Ensure the object being locked matches any previous
    // instructions which bound our variable name to a value.
    Variable lock = new LocalVariable(before.getTopValue());
    return addOrCheckDefinition(lock, bindingSet);
}

/**
 * Scan a method for self call sites.
 * 
 * @param node
 *            the CallGraphNode for the method to be scanned
 */
private void scan(CallGraphNode node) throws CFGBuilderException {
    Method method = node.getMethod();
    CFG cfg = classContext.getCFG(method);

    if (method.isSynchronized())
        hasSynchronization = true;

    Iterator<BasicBlock> i = cfg.blockIterator();
    while (i.hasNext()) {
        BasicBlock block = i.next();
        Iterator<InstructionHandle> j = block.instructionIterator();
        while (j.hasNext()) {
            InstructionHandle handle = j.next();

            Instruction ins = handle.getInstruction();
            if (ins instanceof InvokeInstruction) {
                InvokeInstruction inv = (InvokeInstruction) ins;
                Method called = isSelfCall(inv);
                if (called != null) {
                    // Add edge to call graph
                    CallSite callSite = new CallSite(method, block, handle);
                    callGraph.createEdge(node, callGraph.getNodeForMethod(called), callSite);

                    // Add to called method set
                    calledMethodSet.add(called);
                }
            } else if (ins instanceof MONITORENTER || ins instanceof MONITOREXIT) {
                hasSynchronization = true;
            }
        }
    }
}

@Override
public void visitMONITORENTER(MONITORENTER obj) {
    // Don't know what this sync invocation is doing.
    // Kill all loads.
    ValueNumber topValue = null;
    try {
        topValue = getFrame().getStackValue(0);
    } catch (DataflowAnalysisException e) {
        AnalysisContext.logError("error handling monitor enter in value numbering", e);
    }
    getFrame().killAllLoadsExceptFor(topValue);
    handleNormalInstruction(obj);
}

@Override
public MatchResult match(InstructionHandle handle, ConstantPoolGen cpg, ValueNumberFrame before, ValueNumberFrame after,
        BindingSet bindingSet) throws DataflowAnalysisException {

    // Instruction must be MONITORENTER.
    Instruction ins = handle.getInstruction();
    if (!(ins instanceof MONITORENTER))
        return null;

    // Ensure the object being locked matches any previous
    // instructions which bound our variable name to a value.
    Variable lock = new LocalVariable(before.getTopValue());
    return addOrCheckDefinition(lock, bindingSet);
}