1 /*
   2  * Copyright (c) 2016, 2019, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package jdk.jfr.internal;
  27 
  28 import java.lang.annotation.ElementType;
  29 import java.lang.annotation.Inherited;
  30 import java.lang.annotation.Retention;
  31 import java.lang.annotation.RetentionPolicy;
  32 import java.lang.annotation.Target;
  33 
  34 import jdk.jfr.MetadataDefinition;
  35 
  36 /**
  37  * Event annotation, determines the cutoff above which an event should not be
  38  * recorded, i.e. {@code "20 ms"}.
  39  *
  40  * This settings is only supported for JVM events,
  41  *
  42  * @since 9
  43  */
  44 @MetadataDefinition
  45 @Target({ ElementType.TYPE })
  46 @Inherited
  47 @Retention(RetentionPolicy.RUNTIME)
  48 public @interface Cutoff {
  49     /**
  50      * Settings name {@code "cutoff"} for configuring event cutoffs.
  51      */
  52     public final static String NAME = "cutoff";
  53     public final static String INIFITY = "infinity";
  54 
  55     /**
  56      * Cutoff, for example {@code "20 ms"}.
  57      * <p>
  58      * String representation of a positive {@code Long} value followed by an empty
  59      * space and one of the following units<br>
  60      * <br>
  61      * {@code "ns"} (nanoseconds)<br>
  62      * {@code "us"} (microseconds)<br>
  63      * {@code "ms"} (milliseconds)<br>
  64      * {@code "s"} (seconds)<br>
  65      * {@code "m"} (minutes)<br>
  66      * {@code "h"} (hours)<br>
  67      * {@code "d"} (days)<br>
  68      * <p>
  69      * Example values, {@code "0 ns"}, {@code "10 ms"} and {@code "1 s"}. If the
  70      * events has an infinite timespan, the text {@code"infinity"} should be used.
  71      *
  72      * @return the threshold, default {@code "0 ns"} not {@code null}
  73      */
  74     String value() default "inifity";
  75 }