org.eclipse.jetty.util.thread

Interface Invocable

All Known Subinterfaces:

Callback

All Known Implementing Classes:

Callback.Completable, Callback.Nested, CompletableCallback, CountingCallback, FutureCallback, IteratingCallback, IteratingNestedCallback, SharedBlockingCallback.Blocker

public interface Invocable

A task (typically either a Runnable or Callable that declares how it will behave when invoked:

• blocking, the invocation will certainly block (e.g. performs blocking I/O)
• non-blocking, the invocation will certainly not block
• either, the invocation may block

Static methods and are provided that allow the current thread to be tagged with a ThreadLocal to indicate if it has a blocking invocation type.

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static class	Invocable.InvocationType

Field Summary

Fields

Modifier and Type	Field and Description
static ThreadLocal<Boolean>	__nonBlocking

Method Summary

Modifier and Type	Method and Description
static Runnable	asPreferred(Runnable task, Invocable.InvocationType preferredInvocationType) wrap a task with the to indicate invocation type.
default Invocable.InvocationType	getInvocationType()
static Invocable.InvocationType	getInvocationType(Object o) Get the invocation type of an Object.
static void	invokeNonBlocking(Runnable task) Invoke a task with the calling thread, tagged to indicate that it will not block.
static void	invokePreferNonBlocking(Runnable task) Invoke a task with the calling thread.
static void	invokePreferred(Runnable task, Invocable.InvocationType preferredInvocationType) Invoke a task with the calling thread.
static boolean	isNonBlockingInvocation() Test if the current thread has been tagged as non blocking

Field Detail

__nonBlocking

static final ThreadLocal<Boolean> __nonBlocking

Method Detail

isNonBlockingInvocation

static boolean isNonBlockingInvocation()

Test if the current thread has been tagged as non blocking

Returns:

True if the task the current thread is running has indicated that it will not block.

invokeNonBlocking

static void invokeNonBlocking(Runnable task)

Invoke a task with the calling thread, tagged to indicate that it will not block.

Parameters:

task - The task to invoke.

invokePreferNonBlocking

static void invokePreferNonBlocking(Runnable task)

Invoke a task with the calling thread. If the task is an Invocable of Invocable.InvocationType.EITHER then it is invoked with invokeNonBlocking(Runnable), to indicate the type of invocation that has been assumed.

Parameters:

task - The task to invoke.

invokePreferred

static void invokePreferred(Runnable task,
                            Invocable.InvocationType preferredInvocationType)

Invoke a task with the calling thread. If the task is an Invocable of Invocable.InvocationType.EITHER and the preferredInvocationType is not Invocable.InvocationType.BLOCKING then it is invoked with invokeNonBlocking(Runnable).

Parameters:

task - The task to invoke.

preferredInvocationType - The invocation type to use if the task does not indicate a preference.

asPreferred

static Runnable asPreferred(Runnable task,
                            Invocable.InvocationType preferredInvocationType)

wrap a task with the to indicate invocation type. If the task is an Invocable of Invocable.InvocationType.EITHER and the preferredInvocationType is not Invocable.InvocationType.BLOCKING then it is wrapped with an invocation of invokeNonBlocking(Runnable). otherwise the task itself is returned.

Parameters:

task - The task to invoke.

preferredInvocationType - The invocation type to use if the task does not indicate a preference.

Returns:

A Runnable that invokes the task in the declared or preferred type.

getInvocationType

static Invocable.InvocationType getInvocationType(Object o)

Get the invocation type of an Object.

Parameters:

o - The object to check the invocation type of.

Returns:

If the object is a Invocable, it is coerced and the getInvocationType() used, otherwise Invocable.InvocationType.BLOCKING is returned.

getInvocationType

default Invocable.InvocationType getInvocationType()

Returns:

The InvocationType of this object