/* * Copyright (c) 2008, Oracle and/or its affiliates. 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.  Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package com.sun.tracing; /** * The {@code Probe} interface represents a tracepoint. * * A {@code Probe} instance is obtained by calling the * {@code Provider.getProbe()} method of a provider instance created by * {@code ProviderFactory.createProvider()}.  A {@code Probe} can be used to * trigger a probe manually (provided the correct arguments are passed to * it), or to check a probe to see if anything is currently tracing it. * <p> * A tracing check can be used to avoid lengthy work that might be * needed to set up the probe's arguments.  However, checking * whether the probe is enabled generally takes the same amount of time * as actually triggering the probe. So, you should only check a probe's status * without triggering it if setting up the arguments is very expensive. * <p> * Users do not need to implement this interface: instances are * created automatically by the system when a {@code Provider)} instance is * created. * <p> * @since 1.7 */ public interface Probe {    /**     * Checks whether there is an active trace of this probe.     *     * @return true if an active trace is detected.     */    boolean isEnabled();     /**     * Determines whether a tracepoint is enabled.     *     * Typically, users do not need to use this method. It is called     * automatically when a Provider's instance method is called. Calls to     * this method expect the arguments to match the declared parameters for     * the method associated with the probe.     *     * @param args the parameters to pass to the method.     * @throws IllegalArgumentException if the provided parameters do not     * match the method declaration for this probe.     */    void trigger(Object ... args);}