Scala 3/scala.concurrent/ExecutionContext/parasitic

parasitic

object parasitic extends ExecutionContextExecutor with BatchingExecutor

WARNING: Only ever execute logic which will quickly return control to the caller.

This ExecutionContext steals execution time from other threads by having its Runnables run on the Thread which calls execute and then yielding back control to the caller after *all* its Runnables have been executed. Nested invocations of execute will be trampolined to prevent uncontrolled stack space growth.

When using parasitic with abstractions such as Future it will in many cases be non-deterministic as to which Thread will be executing the logic, as it depends on when/if that Future is completed.

Do *not* call any blocking code in the Runnables submitted to this ExecutionContext as it will prevent progress by other enqueued Runnables and the calling Thread.

Symptoms of misuse of this ExecutionContext include, but are not limited to, deadlocks and severe performance problems.

Any NonFatal or InterruptedExceptions will be reported to the defaultReporter.

Source
ExecutionContext.scala
trait Executor
class Object
trait Matchable
class Any

Value members

Concrete methods

final override def execute(runnable: Runnable): Unit
final override def reportFailure(t: Throwable): Unit
final override def submitForExecution(runnable: Runnable): Unit

Inherited methods

final protected def submitAsyncBatched(runnable: Runnable): Unit

WARNING: Never use both submitAsyncBatched and submitSyncBatched in the same implementation of BatchingExecutor

WARNING: Never use both submitAsyncBatched and submitSyncBatched in the same implementation of BatchingExecutor

Inherited from
BatchingExecutor
Source
BatchingExecutor.scala
final protected def submitSyncBatched(runnable: Runnable): Unit

WARNING: Never use both submitAsyncBatched and submitSyncBatched in the same implementation of BatchingExecutor

WARNING: Never use both submitAsyncBatched and submitSyncBatched in the same implementation of BatchingExecutor

Inherited from
BatchingExecutor
Source
BatchingExecutor.scala

Deprecated and Inherited methods

@deprecated("preparation of ExecutionContexts will be removed", "2.12.0")
def prepare(): ExecutionContext

Prepares for the execution of a task.

Prepares for the execution of a task. Returns the prepared execution context. The recommended implementation of prepare is to return this.

This method should no longer be overridden or called. It was originally expected that prepare would be called by all libraries that consume ExecutionContexts, in order to capture thread local context. However, this usage has proven difficult to implement in practice and instead it is now better to avoid using prepare entirely.

Instead, if an ExecutionContext needs to capture thread local context, it should capture that context when it is constructed, so that it doesn't need any additional preparation later.

Deprecated
Inherited from
ExecutionContext
Source
ExecutionContext.scala