org.krzogr.trackthread.instrument.RunMethodVisitor.java Source code

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Here is the source code for org.krzogr.trackthread.instrument.RunMethodVisitor.java

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/*
 * Copyright (C) 2015 krzogr (krzogr@gmail.com)
 * 
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * 
 * This program 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 for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */

package org.krzogr.trackthread.instrument;

import org.objectweb.asm.Label;
import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.Opcodes;
import org.objectweb.asm.commons.AdviceAdapter;

/**
 * Visitor which performs instrumentation for Thread.run() method.
 */
public class RunMethodVisitor extends AdviceAdapter {
    private Label startFinally = new Label();

    public RunMethodVisitor(final int api, final MethodVisitor mv, final int access, final String name,
            final String desc) {
        super(api, mv, access, name, desc);
    }

    public static boolean matches(final int access, final String name, final String desc) {
        return (access & Opcodes.ACC_PUBLIC) != 0 && "run".equals(name) && "()V".equals(desc);
    }

    @Override
    protected void onMethodEnter() {
        mv.visitVarInsn(Opcodes.ALOAD, 0);
        mv.visitMethodInsn(Opcodes.INVOKESTATIC, "org/krzogr/trackthread/ThreadListeners", "fireThreadRunning",
                "(Ljava/lang/Thread;)V", false);
    }

    @Override
    public void visitCode() {
        super.visitCode();
        mv.visitLabel(startFinally);
    }

    @Override
    public void visitMaxs(final int maxStack, final int maxLocals) {
        Label endFinally = new Label();
        mv.visitTryCatchBlock(startFinally, endFinally, endFinally, null);
        mv.visitLabel(endFinally);
        onFinally(Opcodes.ATHROW);
        mv.visitInsn(Opcodes.ATHROW);
        mv.visitMaxs(maxStack, maxLocals);
    }

    @Override
    protected void onMethodExit(final int opcode) {
        if (opcode != Opcodes.ATHROW) {
            onFinally(opcode);
        }
    }

    private void onFinally(final int opcode) {
        mv.visitVarInsn(Opcodes.ALOAD, 0);
        mv.visitMethodInsn(Opcodes.INVOKESTATIC, "org/krzogr/trackthread/ThreadListeners", "fireThreadStopping",
                "(Ljava/lang/Thread;)V", false);
    }
}