H2O.H2OCountedCompleter (h2o-core version 3.2.0.1 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

Direct Known Subclasses:

ASTGroupBy.ParallelPostGlobal, CreateInteractions, DMatrix.MatrixMulTsk, DTask, FrameCreator, FrameSplitter, H2O.H2OCallback, Handler, MRUtils.ParallelTasks, NetworkTest.NetworkTester, ParseDataset.ParserFJTask, Quantile.QTask, RebalanceDataSet

Enclosing class:

H2O
```
public abstract static class H2O.H2OCountedCompleter<T extends H2O.H2OCountedCompleter>
extends CountedCompleter
implements java.lang.Cloneable, Freezable
```
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

H2O.H2OCountedCompleter()

protected H2O.H2OCountedCompleter(H2O.H2OCountedCompleter completer)

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

Method Summary

Methods
Modifier and Type	Method and Description
`T`	`clone()` Make clone public, but without the annoying exception.
`void`	`compute()` Used by the F/J framework internally to do work.
`protected abstract void`	`compute2()` Override to specify actual work to do
`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`	`nextThrPriority()` If this is a F/J thread, return it's priority+1 - 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.
`boolean`	`onExceptionalCompletion(java.lang.Throwable ex, CountedCompleter caller)` Exceptional completion path; mostly does printing if the exception was not handled earlier in the stack.
`protected byte`	`priority()`
`T`	`read_impl(AutoBuffer ab)` Implementation of the `Iced` serialization protocol, only called by auto-genned code.
`T`	`read(AutoBuffer ab)` Standard "read thyself from the AutoBuffer" call, using the fast Iced protocol.
`T`	`readJSON_impl(AutoBuffer ab)` Implementation of the `Iced` serialization protocol, only called by auto-genned code.
`T`	`readJSON(AutoBuffer ab)` Standard "read thyself from the AutoBuffer" call, using JSON.
`AutoBuffer`	`write_impl(AutoBuffer ab)` Implementation of the `Iced` serialization protocol, only called by auto-genned code.
`AutoBuffer`	`write(AutoBuffer ab)` Standard "write thyself into the AutoBuffer" call, using the fast Iced protocol.
`AutoBuffer`	`writeJSON_impl(AutoBuffer ab)` Implementation of the `Iced` serialization protocol, only called by auto-genned code.
`AutoBuffer`	`writeJSON(AutoBuffer ab)` Standard "write thyself into the AutoBuffer" call, using JSON.

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

Methods inherited from class jsr166y.ForkJoinTask
adapt, adapt, adapt, cancel, compareAndSetForkJoinTaskTag, completeExceptionally, fork, 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
  - H2O.H2OCountedCompleter
```
public H2O.H2OCountedCompleter()
```
  - H2O.H2OCountedCompleter
```
protected H2O.H2OCountedCompleter(H2O.H2OCountedCompleter completer)
```
- Method Detail
  - 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
  - compute2
```
protected abstract void compute2()
```
    Override to specify actual work to do
  - onExceptionalCompletion
```
public boolean onExceptionalCompletion(java.lang.Throwable ex,
                              CountedCompleter caller)
```
    Exceptional completion path; mostly does printing if the exception was not handled earlier in the stack.
    
    Overrides:
    
    onExceptionalCompletion in class CountedCompleter
    
    Parameters:
    ex - the exception
    caller - the task invoking this method (which may be this task itself).
    
    Returns:
    true if this exception should be propagated to this tasks completer, if one exists.
  - priority
```
protected 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
    
    Overrides:
    
    clone in class java.lang.Object
    
    Returns:
    Returns this object cloned.
  - nextThrPriority
```
protected final byte nextThrPriority()
```
    If this is a F/J thread, return it's priority+1 - 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
    
    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
    
    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
    
    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
    
    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
    
    Returns:
    Small integer, unique per-type
  - write_impl
```
public AutoBuffer write_impl(AutoBuffer ab)
```
    Description copied from interface: Freezable
    
    Implementation of the Iced serialization protocol, only called by auto-genned code. Not intended to be called by user code. Override only for custom Iced serializers.
    
    Specified by:
    
    write_impl in interface Freezable
    
    Parameters:
    ab - AutoBuffer to write this object to.
    
    Returns:
    Returns the original AutoBuffer for flow-coding.
  - read_impl
```
public T read_impl(AutoBuffer ab)
```
    Description copied from interface: Freezable
    
    Implementation of the Iced serialization protocol, only called by auto-genned code. Not intended to be called by user code. Override only for custom Iced serializers.
    
    Specified by:
    
    read_impl in interface Freezable
    
    Parameters:
    ab - AutoBuffer to read this object from.
    
    Returns:
    Returns a new instance of object reconstructed from AutoBuffer.
  - writeJSON_impl
```
public AutoBuffer writeJSON_impl(AutoBuffer ab)
```
    Description copied from interface: Freezable
    
    Implementation of the Iced serialization protocol, only called by auto-genned code. Not intended to be called by user code. Override only for custom Iced serializers.
    
    Specified by:
    
    writeJSON_impl in interface Freezable
    
    Parameters:
    ab - AutoBuffer to write this object to.
    
    Returns:
    Returns the original AutoBuffer for flow-coding.
  - readJSON_impl
```
public T readJSON_impl(AutoBuffer ab)
```
    Description copied from interface: Freezable
    
    Implementation of the Iced serialization protocol, only called by auto-genned code. Not intended to be called by user code. Override only for custom Iced serializers.
    
    Specified by:
    
    readJSON_impl in interface Freezable
    
    Parameters:
    ab - AutoBuffer to read this object from.
    
    Returns:
    Returns an instance of object reconstructed from JSON data.

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

H2O.H2OCountedCompleter

H2O.H2OCountedCompleter

Method Detail

compute

compute2

onExceptionalCompletion

priority

clone

nextThrPriority

icer

write

writeJSON

read

readJSON

frozenType

write_impl

read_impl

writeJSON_impl

readJSON_impl