1 /*

     2  * Copyright (c) 2016, 2018, 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;

    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 /**

    35  * Event annotation, specifies the default duration below which an event is not

    36  * recorded (for example, {@code "20 ms"}).

    37  *

    38  * @since 9

    39  */

    40 @MetadataDefinition

    41 @Target({ ElementType.TYPE })

    42 @Inherited

    43 @Retention(RetentionPolicy.RUNTIME)

    44 public @interface Threshold {

    45     /**

    46      * Setting name {@code "threshold"} for configuring event thresholds.

    47      */

    48     public final static String NAME = "threshold";

    49 

    50     /**

    51      * The threshold (for example, {@code "20 ms"}).

    52      * <p>

    53      * A {@code String} representation of a positive {@code Long} value followed by an

    54      * empty space and one of the following units:<br>

    55      * <br>

    56      * {@code "ns"} (nanoseconds)<br>

    57      * {@code "us"} (microseconds)<br>

    58      * {@code "ms"} (milliseconds)<br>

    59      * {@code "s"} (seconds)<br>

    60      * {@code "m"} (minutes)<br>

    61      * {@code "h"} (hours)<br>

    62      * {@code "d"} (days)<br>

    63      * <p>

    64      * Example values are {@code "0 ns"}, {@code "10 ms"}, and {@code "1 s"}.

    65      *

    66      * @return the threshold, default {@code "0 ns"}, not {@code null}

    67      */

    68     String value() default "0 ns";

    69 }