H2O.H2OCountedCompleter (h2o-core 3.42.0 API)

java.lang.Object
- jsr166y.ForkJoinTask<java.lang.Void>
- - jsr166y.CountedCompleter
  - - water.H2O.H2OCountedCompleter<T>

All Implemented Interfaces:

java.io.Serializable, java.lang.Cloneable, java.util.concurrent.Future<java.lang.Void>, Freezable<T>

Direct Known Subclasses:

CreateFrameExecutor, CreateInteractions, DMatrix.MatrixMulTsk, DTask, FrameCreator, FramePersist.LoadFrameDriver, FramePersist.SaveFrameDriver, FrameSplitter, FrameUtils.ExportTaskDriver, H2O.H2OCallback, Handler, LocalMR, ModelBuilder.Driver, NetworkTest.NetworkTester, ParallelizationTask, ParseDataset.ParserFJTask, Quantile.StratifiedQuantilesTask, RebalanceDataSet

Enclosing class:

H2O
```
public abstract static class H2O.H2OCountedCompleter<T extends H2O.H2OCountedCompleter>
extends CountedCompleter
implements java.lang.Cloneable, Freezable<T>
```
Simple wrapper over F/J CountedCompleter to support priority queues. F/J queues are simple unordered (and extremely light weight) queues. However, we frequently need priorities to avoid deadlock and to promote efficient throughput (e.g. failure to respond quickly to TaskGetKey can block an entire node for lack of some small piece of data). So each attempt to do lower-priority F/J work starts with an attempt to work and drain the higher-priority queues.

See Also:

Serialized Form

Constructor Summary

Constructors
Modifier	Constructor and Description
	`H2OCountedCompleter()`
`protected`	`H2OCountedCompleter(byte prior)`
`protected`	`H2OCountedCompleter(H2O.H2OCountedCompleter completer)`
`protected`	`H2OCountedCompleter(H2O.H2OCountedCompleter completer, byte prior)`

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`byte[]`	`asBytes()` Return serialized version of self as a byte array.
`T`	`clone()` Make clone public, but without the annoying exception.
`void`	`compute()` Used by the F/J framework internally to do work.
`void`	`compute1()`
`void`	`compute2()` Override compute3() with actual work without having to worry about tryComplete()
`protected static byte`	`currThrPriority()` If this is a F/J thread, return it's priority - used to lift the priority of a blocking remote call, so the remote node runs it at a higher priority - so we don't deadlock when we burn the local thread.
`int`	`frozenType()` Returns a small dense integer, which is cluster-wide unique per-class.
`protected Icer<T>`	`icer()` Find the serialization delegate for a subclass of this class
`protected byte`	`priority()`
`T`	`read(AutoBuffer ab)` Standard "read thyself from the AutoBuffer" call, using the fast Iced protocol.
`T`	`readJSON(AutoBuffer ab)` Standard "read thyself from the AutoBuffer" call, using JSON.
`T`	`reloadFromBytes(byte[] ary)` Replace yourself with deserialized version from the given bytes.
`AutoBuffer`	`write(AutoBuffer ab)` Standard "write thyself into the AutoBuffer" call, using the fast Iced protocol.
`AutoBuffer`	`writeJSON(AutoBuffer ab)` Standard "write thyself into the AutoBuffer" call, using JSON.

Methods inherited from class jsr166y.CountedCompleter
__tryComplete, addToPendingCount, compareAndSetPendingCount, complete, exec, getCompleter, getPendingCount, getRawResult, onCompletion, onExceptionalCompletion, setCompleter, setPendingCount, setRawResult, tryComplete

Methods inherited from class jsr166y.ForkJoinTask
adapt, adapt, adapt, cancel, compareAndSetForkJoinTaskTag, completeExceptionally, fork, get, get, get, getException, getForkJoinTaskTag, getPool, getQueuedTaskCount, getSurplusQueuedTaskCount, helpQuiesce, inForkJoinPool, invoke, invokeAll, invokeAll, invokeAll, isCancelled, isCompletedAbnormally, isCompletedNormally, isDone, join, peekNextLocalTask, pollNextLocalTask, pollTask, quietlyComplete, quietlyInvoke, quietlyJoin, reinitialize, setForkJoinTaskTag, tryUnfork

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

- Constructor Detail
  - H2OCountedCompleter
```
public H2OCountedCompleter()
```
  - H2OCountedCompleter
```
protected H2OCountedCompleter(H2O.H2OCountedCompleter completer)
```
  - H2OCountedCompleter
```
protected H2OCountedCompleter(byte prior)
```
  - H2OCountedCompleter
```
protected H2OCountedCompleter(H2O.H2OCountedCompleter completer,
                              byte prior)
```
- Method Detail
  - asBytes
```
public byte[] asBytes()
```
    Description copied from interface: Freezable
    
    Return serialized version of self as a byte array. Useful for Freezables directly supported by byte array (@see Chunk) In most cases, just use the Autobuffer version.
    
    Specified by:
    
    asBytes in interface Freezable<T extends H2O.H2OCountedCompleter>
    
    Returns:
    
    serialized bytes
  - reloadFromBytes
```
public T reloadFromBytes(byte[] ary)
```
    Description copied from interface: Freezable
    
    Replace yourself with deserialized version from the given bytes. Useful for Freezables directly supported by byte array (@see Chunk). In most cases, just use the Autobuffer version.
    
    Specified by:
    
    reloadFromBytes in interface Freezable<T extends H2O.H2OCountedCompleter>
    
    Parameters:
    
    ary - byte array containing exactly (i.e. nothing else) the serialized version of the Freezable
    
    Returns:
    
    this freshly reloaded from the given bytes.
  - compute
```
public final void compute()
```
    Used by the F/J framework internally to do work. Once per F/J task, drain the high priority queue before doing any low priority work. Calls compute2() which contains actual work.
    
    Specified by:
    
    compute in class CountedCompleter
  - compute1
```
public void compute1()
```
  - compute2
```
public void compute2()
```
    Override compute3() with actual work without having to worry about tryComplete()
  - priority
```
protected final byte priority()
```
  - clone
```
public final T clone()
```
    Description copied from interface: Freezable
    
    Make clone public, but without the annoying exception.
    
    Specified by:
    
    clone in interface Freezable<T extends H2O.H2OCountedCompleter>
    
    Overrides:
    
    clone in class java.lang.Object
    
    Returns:
    
    Returns this object cloned.
  - currThrPriority
```
protected static byte currThrPriority()
```
    If this is a F/J thread, return it's priority - used to lift the priority of a blocking remote call, so the remote node runs it at a higher priority - so we don't deadlock when we burn the local thread.
  - icer
```
protected Icer<T> icer()
```
    Find the serialization delegate for a subclass of this class
  - write
```
public final AutoBuffer write(AutoBuffer ab)
```
    Description copied from interface: Freezable
    
    Standard "write thyself into the AutoBuffer" call, using the fast Iced protocol. Real work is in the delegate Icer classes.
    
    Specified by:
    
    write in interface Freezable<T extends H2O.H2OCountedCompleter>
    
    Parameters:
    
    ab - AutoBuffer to write this object to.
    
    Returns:
    
    Returns the original AutoBuffer for flow-coding.
  - writeJSON
```
public final AutoBuffer writeJSON(AutoBuffer ab)
```
    Description copied from interface: Freezable
    
    Standard "write thyself into the AutoBuffer" call, using JSON. Real work is in the delegate Icer classes.
    
    Specified by:
    
    writeJSON in interface Freezable<T extends H2O.H2OCountedCompleter>
    
    Parameters:
    
    ab - AutoBuffer to write this object to.
    
    Returns:
    
    Returns the original AutoBuffer for flow-coding.
  - read
```
public final T read(AutoBuffer ab)
```
    Description copied from interface: Freezable
    
    Standard "read thyself from the AutoBuffer" call, using the fast Iced protocol. Real work is in the delegate Icer classes.
    
    Specified by:
    
    read in interface Freezable<T extends H2O.H2OCountedCompleter>
    
    Parameters:
    
    ab - AutoBuffer to read this object from.
    
    Returns:
    
    Returns a new instance of object reconstructed from AutoBuffer.
  - readJSON
```
public final T readJSON(AutoBuffer ab)
```
    Description copied from interface: Freezable
    
    Standard "read thyself from the AutoBuffer" call, using JSON. Real work is in the delegate Icer classes.
    
    Specified by:
    
    readJSON in interface Freezable<T extends H2O.H2OCountedCompleter>
    
    Parameters:
    
    ab - AutoBuffer to read this object from.
    
    Returns:
    
    Returns an instance of object reconstructed from JSON data.
  - frozenType
```
public final int frozenType()
```
    Description copied from interface: Freezable
    
    Returns a small dense integer, which is cluster-wide unique per-class. Useful as an array index.
    
    Specified by:
    
    frozenType in interface Freezable<T extends H2O.H2OCountedCompleter>
    
    Returns:
    
    Small integer, unique per-type

Class H2O.H2OCountedCompleter<T extends H2O.H2OCountedCompleter>

Constructor Summary

Method Summary

Methods inherited from class jsr166y.CountedCompleter

Methods inherited from class jsr166y.ForkJoinTask

Methods inherited from class java.lang.Object

Constructor Detail

H2OCountedCompleter

H2OCountedCompleter

H2OCountedCompleter

H2OCountedCompleter

Method Detail

asBytes

reloadFromBytes

compute

compute1

compute2

priority

clone

currThrPriority

icer

write

writeJSON

read

readJSON

frozenType