Returns the clock drift tolerance in nanoseconds.

Related system properties:

• rx3.scheduler.drift-tolerance, long, default 15
• rx3.scheduler.drift-tolerance-unit, string, default minutes, supports seconds and milliseconds.

Returns:long

the tolerance in nanoseconds

Since

2.0

Retrieves or creates a new Scheduler.Worker that represents sequential execution of actions.

When work is completed, the Worker instance should be released by calling Scheduler.Worker#dispose() to avoid potential resource leaks in the underlying task-execution scheme.

Work on a Scheduler.Worker is guaranteed to be sequential and non-overlapping.

Returns:@NonNull Scheduler.Worker

a Worker representing a serial queue of actions to be executed

Annotations

@NonNull

Returns the 'current time' of the Scheduler in the specified time unit.

Parameters

unit:@NonNull TimeUnit

the time unit

Returns:long

the 'current time'

Exceptions

NullPointerException:

if unit is null

Since

2.0

Schedules the given task on this Scheduler without any time delay.

This method is safe to be called from multiple threads but there are no ordering or non-overlapping guarantees between tasks.

Parameters

run:@NonNull Runnable

the task to execute

Returns:@NonNull Disposable

the Disposable instance that let's one cancel this particular task.

Annotations

@NonNull

Exceptions

NullPointerException:

if run is null

Since

2.0

Schedules the execution of the given task with the given time delay.

This method is safe to be called from multiple threads but there are no ordering guarantees between tasks.

Parameters

run:@NonNull Runnable

the task to schedule

delay:long

the delay amount, non-positive values indicate non-delayed scheduling

unit:@NonNull TimeUnit

the unit of measure of the delay amount

Returns:@NonNull Disposable

the Disposable that let's one cancel this particular delayed task.

Annotations

@NonNull

Exceptions

NullPointerException:

if run or unit is null

Since

2.0

Schedules a periodic execution of the given task with the given initial time delay and repeat period.

This method is safe to be called from multiple threads but there are no ordering guarantees between tasks.

The periodic execution is at a fixed rate, that is, the first execution will be after the initialDelay, the second after initialDelay + period, the third after initialDelay + 2 * period, and so on.

Parameters

run:@NonNull Runnable

the task to schedule

initialDelay:long

the initial delay amount, non-positive values indicate non-delayed scheduling

period:long

the period at which the task should be re-executed

unit:@NonNull TimeUnit

the unit of measure of the delay amount

Returns:@NonNull Disposable

the Disposable that let's one cancel this particular delayed task.

Annotations

@NonNull

Exceptions

NullPointerException:

if run or unit is null

Since

2.0

Instructs the Scheduler instance to stop threads, stop accepting tasks on any outstanding Worker instances and clean up any associated resources with this Scheduler.

Implementations should make sure the call is idempotent, thread-safe and should not throw any RuntimeException if it doesn't support this functionality.

Since

2.0

Allows the Scheduler instance to start threads and accept tasks on them.

Implementations should make sure the call is idempotent, thread-safe and should not throw any RuntimeException if it doesn't support this functionality.

Since

2.0

Allows the use of operators for controlling the timing around when actions scheduled on workers are actually done. This makes it possible to layer additional behavior on this Scheduler. The only parameter is a function that flattens an Flowable of Flowable of Completables into just one Completable. There must be a chain of operators connecting the returned value to the source Flowable otherwise any work scheduled on the returned Scheduler will not be executed.

When Scheduler#createWorker() is invoked a Flowable of Completables is onNext'd to the combinator to be flattened. If the inner Flowable is not immediately subscribed to an calls to Worker#schedule are buffered. Once the Flowable is subscribed to actions are then onNext'd as Completables.

Finally the actions scheduled on the parent Scheduler when the inner most Completables are subscribed to.

When the Worker is unsubscribed the Completable emits an onComplete and triggers any behavior in the flattening operator. The Flowable and all Completables give to the flattening function never onError.

Limit the amount concurrency two at a time without creating a new fix size thread pool:

Scheduler limitScheduler = Schedulers.computation().when(workers -> {
 // use merge max concurrent to limit the number of concurrent
 // callbacks two at a time
 return Completable.merge(Flowable.merge(workers), 2);
});

This is a slightly different way to limit the concurrency but it has some interesting benefits and drawbacks to the method above. It works by limited the number of concurrent Workers rather than individual actions. Generally each Flowable uses its own Worker. This means that this will essentially limit the number of concurrent subscribes. The danger comes from using operators like Flowable#zip(org.reactivestreams.Publisher, org.reactivestreams.Publisher, io.reactivex.rxjava3.functions.BiFunction) where subscribing to the first Flowable could deadlock the subscription to the second.

Scheduler limitScheduler = Schedulers.computation().when(workers -> {
 // use merge max concurrent to limit the number of concurrent
 // Flowables two at a time
 return Completable.merge(Flowable.merge(workers, 2));
});

Scheduler slowScheduler = Schedulers.computation().when(workers -> {
 // use concatenate to make each worker happen one at a time.
 return Completable.concat(workers.map(actions -> {
     // delay the starting of the next worker by 1 second.
     return Completable.merge(actions.delaySubscription(1, TimeUnit.SECONDS));
 }));
});

History: 2.0.1 - experimental

Parameters

<S>

a Scheduler and a Subscription

combine:@NonNull Function<Flowable<Flowable<Completable>>, Completable>

the function that takes a two-level nested Flowable sequence of a Completable and returns the Completable that will be subscribed to and should trigger the execution of the scheduled Actions.

Returns:S

the Scheduler with the customized execution behavior

Annotations

@SuppressWarnings:unchecked

@NonNull

Exceptions

NullPointerException:

if combine is null

Since

2.1