org.eclipse.jetty.util.thread.ExecutionStrategy Maven / Gradle / Ivy
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package org.eclipse.jetty.util.thread;
/**
* An {@link ExecutionStrategy} executes {@link Runnable} tasks produced by a {@link Producer}.
* The strategy to execute the task may vary depending on the implementation; the task may be
* run in the calling thread, or in a new thread, etc.
* The strategy delegates the production of tasks to a {@link Producer}, and continues to
* execute tasks until the producer continues to produce them.
*/
public interface ExecutionStrategy
{
/**
* Initiates (or resumes) the task production and consumption.
* This method guarantees that the task is never run by the
* thread that called this method.
*
* TODO review the need for this (only used by HTTP2 push)
*
* @see #produce()
*/
void dispatch();
/**
* Initiates (or resumes) the task production and consumption.
* The produced task may be run by the same thread that called
* this method.
*
* @see #dispatch()
*/
void produce();
/**
* A producer of {@link Runnable} tasks to run.
* The {@link ExecutionStrategy} will repeatedly invoke {@link #produce()} until
* the producer returns null, indicating that it has nothing more to produce.
* When no more tasks can be produced, implementations should arrange for the
* {@link ExecutionStrategy} to be invoked again in case an external event resumes
* the tasks production.
*/
interface Producer
{
/**
* Produces a task to be executed.
*
* @return a task to executed or null if there are no more tasks to execute
*/
Runnable produce();
}
}