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.Retention;

    30 import java.lang.annotation.RetentionPolicy;

    31 import java.lang.annotation.Target;

    32 

    33 /**

    34  * Event field annotation, specifies that the value is a frequency, measured in Hz.

    35  *

    36  * @since 9

    37  */

    38 @MetadataDefinition

    39 @ContentType

    40 @Label("Frequency")

    41 @Description("Measure of how often something occurs, in Hertz")

    42 @Retention(RetentionPolicy.RUNTIME)

    43 @Target({ElementType.FIELD, ElementType.METHOD})

    44 public @interface Frequency {

    45 }