Package org.threadly.concurrent.wrapper.limiter

Class ExecutorQueueLimitRejector

java.lang.Object

org.threadly.concurrent.AbstractSubmitterExecutor

org.threadly.concurrent.wrapper.limiter.ExecutorQueueLimitRejector

All Implemented Interfaces:

java.util.concurrent.Executor, SubmitterExecutor

public class ExecutorQueueLimitRejector
extends AbstractSubmitterExecutor

A simple way to limit any Executor so that queues are managed. In addition this queue is tracked completely independent of the Executor's actual queue, so these can be distributed in code to limit queues differently to different parts of the system, while letting them all back the same Executor.

Once the limit has been reached, if additional tasks are supplied a RejectedExecutionException will be thrown. This is the threadly equivalent of supplying a limited sized blocking queue to a java.util.concurrent thread pool.

See SubmitterSchedulerQueueLimitRejector, SchedulerServiceQueueLimitRejector and PrioritySchedulerServiceQueueLimitRejector as other possible implementations.

Since:

4.6.0 (since 4.3.0 at org.threadly.concurrent.limiter)

Constructor Summary

Constructors

Constructor	Description
ExecutorQueueLimitRejector(java.util.concurrent.Executor parentExecutor, int queuedTaskLimit)	Constructs a new ExecutorQueueLimitRejector with the provided scheduler and limit.
ExecutorQueueLimitRejector(java.util.concurrent.Executor parentExecutor, int queuedTaskLimit, RejectedExecutionHandler rejectedExecutionHandler)	Constructs a new ExecutorQueueLimitRejector with the provided scheduler and limit.

Method Summary

Modifier and Type	Method	Description
int	getQueuedTaskCount()	Invoked to check how many tasks are currently being tracked as queued by this limiter.
int	getQueueLimit()	Invoked to check the currently set queue limit.
void	setQueueLimit(int newLimit)	Invoked to change the set limit.

Methods inherited from class org.threadly.concurrent.AbstractSubmitterExecutor

execute, submit, submit

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.threadly.concurrent.SubmitterExecutor

submit

Constructor Detail

ExecutorQueueLimitRejector

public ExecutorQueueLimitRejector(java.util.concurrent.Executor parentExecutor,
                                  int queuedTaskLimit)

Constructs a new ExecutorQueueLimitRejector with the provided scheduler and limit.

Parameters:

parentExecutor - Executor to execute tasks on to

queuedTaskLimit - Maximum number of queued tasks before executions should be rejected

ExecutorQueueLimitRejector

public ExecutorQueueLimitRejector(java.util.concurrent.Executor parentExecutor,
                                  int queuedTaskLimit,
                                  RejectedExecutionHandler rejectedExecutionHandler)

Constructs a new ExecutorQueueLimitRejector with the provided scheduler and limit.

Parameters:

parentExecutor - Executor to execute tasks on to

queuedTaskLimit - Maximum number of queued tasks before executions should be rejected

rejectedExecutionHandler - Handler to accept tasks which could not be executed due to queue size

Since:

4.8.0

Method Detail

getQueuedTaskCount

public int getQueuedTaskCount()

Invoked to check how many tasks are currently being tracked as queued by this limiter.

Returns:

Number of tracked tasks waiting for execution to start

getQueueLimit

public int getQueueLimit()

Invoked to check the currently set queue limit.

Returns:

Maximum number of tasks allowed to queue in the parent executor

setQueueLimit

public void setQueueLimit(int newLimit)

Invoked to change the set limit. Negative and zero limits are allowed, but they will cause all executions to be rejected. If set below the current queue size, those tasks will still remain queued for execution.

Parameters:

newLimit - New limit to avoid executions