BackpressureDrainManager

java.lang.Object
- java.lang.Number
- - java.util.concurrent.atomic.AtomicLong
  - - rx.internal.util.BackpressureDrainManager

All Implemented Interfaces:

Serializable, Producer
```
@Experimental
public final class BackpressureDrainManager
extends AtomicLong
implements Producer
```
Manages the producer-backpressure-consumer interplay by matching up available elements with requested elements and/or terminal events.

Since:

1.1.0

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
`static interface`	`BackpressureDrainManager.BackpressureQueueCallback` Interface representing the minimal callbacks required to operate the drain part of a backpressure system.

Field Summary

Fields

Modifier and Type	Field and Description
`protected BackpressureDrainManager.BackpressureQueueCallback`	`actual` The callbacks to manage the drain.
`protected boolean`	`emitting` Indicates if one is in emitting phase, guarded by this.
`protected Throwable`	`exception` Indicates an error state, barrier is provided via terminated.
`protected boolean`	`terminated` Indicates a terminal state.

Constructor Summary

Constructors

Constructor and Description
`BackpressureDrainManager(BackpressureDrainManager.BackpressureQueueCallback actual)` Constructs a backpressure drain manager with 0 requesedCount, no terminal event and not emitting.

Method Summary

All Methods

Instance Methods

Concrete Methods
Modifier and Type	Method and Description
`void`	`drain()` Try to drain the "queued" elements and terminal events by considering the available and requested event counts.
`boolean`	`isTerminated()` Checks if a terminal state has been reached.
`void`	`request(long n)` Request a certain maximum number of items from this Producer.
`void`	`terminate()` Move into a terminal state.
`void`	`terminate(Throwable error)` Move into a terminal state with an exception.
`void`	`terminateAndDrain()` Move into a terminal state and drain.
`void`	`terminateAndDrain(Throwable error)` Move into a terminal state with an exception and drain.

Methods inherited from class java.util.concurrent.atomic.AtomicLong
accumulateAndGet, addAndGet, compareAndSet, decrementAndGet, doubleValue, floatValue, get, getAndAccumulate, getAndAdd, getAndDecrement, getAndIncrement, getAndSet, getAndUpdate, incrementAndGet, intValue, lazySet, longValue, set, toString, updateAndGet, weakCompareAndSet

Methods inherited from class java.lang.Number
byteValue, shortValue

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Field Detail
  - emitting
```
protected boolean emitting
```
    Indicates if one is in emitting phase, guarded by this.
  - terminated
```
protected volatile boolean terminated
```
    Indicates a terminal state.
  - exception
```
protected Throwable exception
```
    Indicates an error state, barrier is provided via terminated.
  - actual
```
protected final BackpressureDrainManager.BackpressureQueueCallback actual
```
    The callbacks to manage the drain.
- Constructor Detail
  - BackpressureDrainManager
```
public BackpressureDrainManager(BackpressureDrainManager.BackpressureQueueCallback actual)
```
    Constructs a backpressure drain manager with 0 requesedCount, no terminal event and not emitting.
    
    Parameters:
    
    actual - he queue callback to check for new element availability
- Method Detail
  - isTerminated
```
public final boolean isTerminated()
```
    Checks if a terminal state has been reached.
    
    Returns:
    
    true if a terminal state has been reached
  - terminate
```
public final void terminate()
```
    Move into a terminal state. Call drain() anytime after.
  - terminate
```
public final void terminate(Throwable error)
```
    Move into a terminal state with an exception. Call drain() anytime after.
    Serialized access is expected with respect to element emission.
    
    Parameters:
    
    error - the exception to deliver
  - terminateAndDrain
```
public final void terminateAndDrain()
```
    Move into a terminal state and drain.
  - terminateAndDrain
```
public final void terminateAndDrain(Throwable error)
```
    Move into a terminal state with an exception and drain.
    Serialized access is expected with respect to element emission.
    
    Parameters:
    
    error - the exception to deliver
  - request
```
public final void request(long n)
```
    Description copied from interface: Producer
    Request a certain maximum number of items from this Producer. This is a way of requesting backpressure. To disable backpressure, pass Long.MAX_VALUE to this method.
    Requests are additive but if a sequence of requests totals more than Long.MAX_VALUE then Long.MAX_VALUE requests will be actioned and the extras may be ignored. Arriving at Long.MAX_VALUE by addition of requests cannot be assumed to disable backpressure. For example, the code below may result in Long.MAX_VALUE requests being actioned only.
```
 request(100);
 request(Long.MAX_VALUE-1);
 
```
    Specified by:
    
    request in interface Producer
    
    Parameters:
    
    n - the maximum number of items you want this Producer to produce, or Long.MAX_VALUE if you want the Producer to produce items at its own pace
  - drain
```
public final void drain()
```
    Try to drain the "queued" elements and terminal events by considering the available and requested event counts.

Class BackpressureDrainManager

Nested Class Summary

Nested Classes

Field Summary

Fields

Constructor Summary

Constructors

Method Summary

Methods inherited from class java.util.concurrent.atomic.AtomicLong

Methods inherited from class java.lang.Number

Methods inherited from class java.lang.Object

Field Detail

emitting

terminated

exception

actual

Constructor Detail

BackpressureDrainManager

Method Detail

isTerminated

terminate

terminate

terminateAndDrain

terminateAndDrain

request

drain