com.sun.btrace.util.TimeStampHelper Maven / Gradle / Ivy

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/*
 * Copyright 2008-2010 Sun Microsystems, Inc.  All Rights Reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Sun designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Sun in the LICENSE file that accompanied this code.
 *
 * This code 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
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 */

package com.sun.btrace.util;

import com.sun.btrace.org.objectweb.asm.ClassVisitor;
import com.sun.btrace.org.objectweb.asm.MethodVisitor;
import static com.sun.btrace.org.objectweb.asm.Opcodes.*;


/**
 *
 * @author Jaroslav Bachorik 
 */
public class TimeStampHelper {
    final public static String TIME_STAMP_NAME = "$btrace$time$stamp";

    public static void generateTimeStampGetter(ClassVisitor cv) {
        MethodVisitor timestamp = cv.visitMethod(ACC_STATIC + ACC_PRIVATE + ACC_FINAL, TIME_STAMP_NAME, "()J", null, new String[0]);
        timestamp.visitCode();
        timestamp.visitMethodInsn(INVOKESTATIC, "java/lang/System", "nanoTime", "()J");
        timestamp.visitInsn(LRETURN);
        timestamp.visitMaxs(1, 0);
        timestamp.visitEnd();
    }

    public static void generateTimeStampAccess(MethodVisitor mv, String className) {
        if (Boolean.getBoolean("btrace.timer.sampled")) {
            mv.visitFieldInsn(GETSTATIC, "com/sun/btrace/BTraceRuntime", "TIMESTAMP", "J");
        } else {
            mv.visitMethodInsn(INVOKESTATIC, className.replace(".", "/"), TIME_STAMP_NAME, "()J");
        }
    }
}