| /* |
| * 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 |
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| * 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); |
| } |