Concurrency Policy (concurrencyPolicy)

A set of behaviors and constraints that are applied to tasks that are capable of asynchronous execution, such as maximum concurrency and maximum queue size.

Name	Type	Default	Description
id	string		A unique configuration ID.
max	int Min: 1		Specifies the maximum number of tasks that can run simultaneously. The default is Integer.MAX_VALUE. Maximum concurrency can be updated while tasks are in progress. If the maximum concurrency is reduced below the number of concurrently running tasks, the update goes into effect gradually as in-progress tasks complete, rather than canceling them.
maxPolicy	loose strict	loose	Indicates whether to loosely or strictly enforce maximum concurrency for tasks that run on the task submitter's thread. If the concurrency policy is not configured to run tasks on virtual threads, the invokeAll and invokeAny methods can sometimes run tasks on the task submitter's thread. This situation happens when you use the untimed invokeAll method, or, if you only supply a single task, when you use the untimed invokeAny method. If the run-if-queue-full attribute is configured, tasks can also run on the task submitter's thread when you use the execute and submit methods. In all of these cases, this attribute determines whether running on the submitter's thread counts against the maximum concurrency. Completion stage tasks that run inline do not count against the maximum concurrency, regardless of the maximum policy. loose Maximum concurrency is loosely enforced. Tasks are allowed to run on the task submitter's thread without counting against maximum concurrency. strict Maximum concurrency is strictly enforced. Tasks that run on the task submitter's thread count towards maximum concurrency. This policy does not allow tasks to run on the task submitter's thread when already at maximum concurrency.
maxQueueSize	int Min: 1		Specifies the maximum number of tasks that can be in the queue waiting for execution. As tasks are started, canceled, or aborted, they are removed from the queue. When the queue is at capacity and another task is submitted, the behavior is determined by the maximum wait for enqueue and run-if-queue-full attributes. To ensure that a specific number of tasks can be queued within a short interval of time, use a maximum queue size that is at least as large as that amount. The default maximum queue size is Integer.MAX_VALUE. Maximum queue size can be updated while tasks are both in progress or queued for execution. If the maximum queue size is reduced below the current number of queued tasks, the update goes into effect gradually rather than automatically canceling the excess queued tasks.
maxWaitForEnqueue	A period of time with millisecond precision	0	Specifies the maximum duration of time to wait for enqueuing a task. If unable to enqueue the task within this interval, the task submission is subject to the run-if-queue-full policy. When the maximum wait for enqueue is updated, the update applies only to tasks submitted after that point. Tasks submissions that were already waiting for a queue position continue to wait per the previously configured value. Specify a positive integer followed by a unit of time, which can be hours (h), minutes (m), seconds (s), or milliseconds (ms). For example, specify 500 milliseconds as 500ms. You can include multiple values in a single entry. For example, 1s500ms is equivalent to 1.5 seconds.
runIfQueueFull	boolean	false	Applies when using the <execute> or <submit> methods. Indicates whether or not to run the task on the submitter's thread when the queue is full and the maximum wait for enqueue was exceeded. If the maximum policy is configured to strict, the ability to run on the submitter's thread is additionally contingent on the maximum concurrency constraint. If the task cannot run on the submitter's thread, the task submission is rejected after the maximum wait for enqueue elapses.
startTimeout	A period of time with millisecond precision		Specifies the maximum amount of time that may elapse between the task submission and the task start. By default, tasks do not time out. If both a maximum wait for enqueue and a start timeout are enabled, configure the start timeout to be larger than the maximum wait for enqueue. When the start timeout is updated while in use, the new start timeout value applies to tasks submitted after the update occurs. Specify a positive integer followed by a unit of time, which can be hours (h), minutes (m), seconds (s), or milliseconds (ms). For example, specify 500 milliseconds as 500ms. You can include multiple values in a single entry. For example, 1s500ms is equivalent to 1.5 seconds.

Name

Type

Default

Description

string

A unique configuration ID.

max

int
Min: 1

Specifies the maximum number of tasks that can run simultaneously. The default is Integer.MAX_VALUE. Maximum concurrency can be updated while tasks are in progress. If the maximum concurrency is reduced below the number of concurrently running tasks, the update goes into effect gradually as in-progress tasks complete, rather than canceling them.

maxPolicy

loose
strict

loose

Indicates whether to loosely or strictly enforce maximum concurrency for tasks that run on the task submitter's thread. If the concurrency policy is not configured to run tasks on virtual threads, the invokeAll and invokeAny methods can sometimes run tasks on the task submitter's thread. This situation happens when you use the untimed invokeAll method, or, if you only supply a single task, when you use the untimed invokeAny method. If the run-if-queue-full attribute is configured, tasks can also run on the task submitter's thread when you use the execute and submit methods. In all of these cases, this attribute determines whether running on the submitter's thread counts against the maximum concurrency. Completion stage tasks that run inline do not count against the maximum concurrency, regardless of the maximum policy.
loose
Maximum concurrency is loosely enforced. Tasks are allowed to run on the task submitter's thread without counting against maximum concurrency.
strict
Maximum concurrency is strictly enforced. Tasks that run on the task submitter's thread count towards maximum concurrency. This policy does not allow tasks to run on the task submitter's thread when already at maximum concurrency.

maxQueueSize

int
Min: 1

Specifies the maximum number of tasks that can be in the queue waiting for execution. As tasks are started, canceled, or aborted, they are removed from the queue. When the queue is at capacity and another task is submitted, the behavior is determined by the maximum wait for enqueue and run-if-queue-full attributes. To ensure that a specific number of tasks can be queued within a short interval of time, use a maximum queue size that is at least as large as that amount. The default maximum queue size is Integer.MAX_VALUE. Maximum queue size can be updated while tasks are both in progress or queued for execution. If the maximum queue size is reduced below the current number of queued tasks, the update goes into effect gradually rather than automatically canceling the excess queued tasks.

maxWaitForEnqueue

A period of time with millisecond precision

Specifies the maximum duration of time to wait for enqueuing a task. If unable to enqueue the task within this interval, the task submission is subject to the run-if-queue-full policy. When the maximum wait for enqueue is updated, the update applies only to tasks submitted after that point. Tasks submissions that were already waiting for a queue position continue to wait per the previously configured value. Specify a positive integer followed by a unit of time, which can be hours (h), minutes (m), seconds (s), or milliseconds (ms). For example, specify 500 milliseconds as 500ms. You can include multiple values in a single entry. For example, 1s500ms is equivalent to 1.5 seconds.

runIfQueueFull

boolean

false

Applies when using the <execute> or <submit> methods. Indicates whether or not to run the task on the submitter's thread when the queue is full and the maximum wait for enqueue was exceeded. If the maximum policy is configured to strict, the ability to run on the submitter's thread is additionally contingent on the maximum concurrency constraint. If the task cannot run on the submitter's thread, the task submission is rejected after the maximum wait for enqueue elapses.

startTimeout

A period of time with millisecond precision

Specifies the maximum amount of time that may elapse between the task submission and the task start. By default, tasks do not time out. If both a maximum wait for enqueue and a start timeout are enabled, configure the start timeout to be larger than the maximum wait for enqueue. When the start timeout is updated while in use, the new start timeout value applies to tasks submitted after the update occurs. Specify a positive integer followed by a unit of time, which can be hours (h), minutes (m), seconds (s), or milliseconds (ms). For example, specify 500 milliseconds as 500ms. You can include multiple values in a single entry. For example, 1s500ms is equivalent to 1.5 seconds.