org.openjdk.jmh.annotations.Group Maven / Gradle / Ivy
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package org.openjdk.jmh.annotations;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
/**
* Execution group.
*
* Multiple {@link Benchmark} methods can be bound in the execution group
* to produce the asymmetric benchmark. Each execution group contains of one
* or more threads. Each thread within a particular execution group executes
* one of {@link Group}-annotated {@link Benchmark} methods. The number of
* threads executing a particular {@link Benchmark} defaults to a single thread,
* and can be overridden by {@link GroupThreads}.
*
* Multiple copies of an execution group may participate in the run, and
* the number of groups depends on the number of worker threads requested.
* JMH will take the requested number of worker threads, round it up to execution
* group size, and then distribute the threads among the (multiple) groups.
* Among other things, this guarantees fully-populated execution groups.
* For example, running {@link Group} with two {@link Benchmark} methods,
* each having {@link GroupThreads}(4), will run 8*N threads, where N is an
* integer.
*
* The group tag is used as the generated benchmark name. The result of each
* benchmark method in isolation is recorded as secondary result named by the
* original method name.
*/
@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
public @interface Group {
/**
* Group tag. Should be a valid Java identifier.
* @return group tag
*/
String value() default "group";
}