Select (org.codehaus.gpars)

groovyx.gpars.dataflow.Select

A Select allows the user to select a value from multiple channels, which have a value available for read at the moment. It can either pick a channel randomly, when using the plain select method, or with precedence towards channels with lower position indexes, when the prioritySelect method is used. If a value is not available immediately in any of the channels, Select will wait for the first value to arrive in any of the channels.
Both 'select' and 'prioritySelect' methods come in two flavours - blocking, which wait till a value is available in a channel, and messaging, which send out a message to the specified message handler, as soon as a message is available. Optionally, all methods allow the user to specify a boolean mask, assigning each select 's input channel a flag indicating, whether it should be included in the select operation. This is useful when handling state to selectively block some inputs in some states.

Authors:
Vaclav Pech Date: 30th Sep 2010

Field Summary

Fields
Modifiers	Name	Description
`static java.lang.String`	`TIMEOUT`	A value that gets bound to timeout channels through the Select.createTimeout() method
`private SelectBase<T>`	`selectBase`

Constructor Summary

Constructors
Constructor and description
`Select (PGroup pGroup, SelectableChannel<? extends T>... channels)` @param pGroup The group, the thread pool of which should be used for notification message handlers
`Select (PGroup pGroup, java.util.List<SelectableChannel<? extends T>> channels)` @param pGroup The group, the thread pool of which should be used for notification message handlers

Methods Summary

Methods
Type	Name and description
`SelectResult<T>`	`call()` Selects a value from a single randomly chosen input channel, which has a value available for read.
`SelectResult<T>`	`call(java.util.List<java.lang.Boolean> mask)` Selects a value from a single randomly chosen input channel, which has a value available for read.
`void`	`call(MessageStream messageStream)` Selects a value from a single randomly chosen input channel, which has a value available for read.
`void`	`call(MessageStream messageStream, java.util.List<java.lang.Boolean> mask)` Selects a value from a single randomly chosen input channel, which has a value available for read.
`static DataflowReadChannel<java.lang.String>`	`createTimeout(long timeout)` Creates a timeout channel (DataflowVariable) that will bind a Select.TIMEOUT value after the specified timeout.
`SelectResult<T>`	`prioritySelect()` Selects a value from a single input channel, which has a value available for read.
`SelectResult<T>`	`prioritySelect(java.util.List<java.lang.Boolean> mask)` Selects a value from a single input channel, which has a value available for read.
`void`	`prioritySelect(MessageStream messageStream)` Selects a value from a single input channel, which has a value available for read.
`void`	`prioritySelect(MessageStream messageStream, java.util.List<java.lang.Boolean> mask)` Selects a value from a single input channel, which has a value available for read.
`Promise<SelectResult<T>>`	`prioritySelectToPromise()` Selects asynchronously a value from a single input channel, which has a value available for read.
`Promise<SelectResult<T>>`	`prioritySelectToPromise(java.util.List<java.lang.Boolean> mask)` Selects asynchronously a value from a single input channel, which has a value available for read.
`SelectResult<T>`	`select()` Selects a value from a single randomly chosen input channel, which has a value available for read.
`SelectResult<T>`	`select(java.util.List<java.lang.Boolean> mask)` Selects a value from a single randomly chosen input channel, which has a value available for read.
`void`	`select(MessageStream messageStream)` Selects a value from a single randomly chosen input channel, which has a value available for read.
`void`	`select(MessageStream messageStream, java.util.List<java.lang.Boolean> mask)` Selects a value from a single randomly chosen input channel, which has a value available for read.
`private void`	`select(MessageStream messageStream, int startIndex, java.util.List<java.lang.Boolean> mask)` Invokes the internal select base with a SelectRequest instance ensuring a message is sent, once a value has been selected
`private SelectResult<T>`	`select(int startIndex, java.util.List<java.lang.Boolean> mask)` Invokes the internal select base with a SelectRequest instance ensuring the current thread can continue returning the correct value, once a value has been selected
`Promise<SelectResult<T>>`	`selectToPromise()` Selects asynchronously a value from a single randomly chosen input channel, which has a value available for read.
`Promise<SelectResult<T>>`	`selectToPromise(java.util.List<java.lang.Boolean> mask)` /** Selects asynchronously a value from a single randomly chosen input channel, which has a value available for read.
`private Promise<SelectResult<T>>`	`selectToPromise(int startIndex, java.util.List<java.lang.Boolean> mask)` Invokes the internal select base with a SelectRequest instance ensuring a message is sent, once a value has been selected

Inherited Methods Summary

Inherited Methods
Methods inherited from class	Name
`class java.lang.Object`	`java.lang.Object#wait(), java.lang.Object#wait(long, int), java.lang.Object#wait(long), java.lang.Object#equals(java.lang.Object), java.lang.Object#toString(), java.lang.Object#hashCode(), java.lang.Object#getClass(), java.lang.Object#notify(), java.lang.Object#notifyAll()`

- Field Detail
  - public static final java.lang.String TIMEOUT
    
    A value that gets bound to timeout channels through the Select.createTimeout() method
  - private final SelectBase<T> selectBase
- Constructor Detail
  - @java.lang.SuppressWarnings({"OverloadedVarargsMethod"}) public Select(PGroup pGroup, SelectableChannel<? extends T>... channels)
    
    Parameters:
    pGroup - The group, the thread pool of which should be used for notification message handlers
    channels - The input channels to select from
  - public Select(PGroup pGroup, java.util.List<SelectableChannel<? extends T>> channels)
    
    Parameters:
    pGroup - The group, the thread pool of which should be used for notification message handlers
    channels - The list of input channels to select from
- Method Detail
  - public final SelectResult<T> call()
    
    Selects a value from a single randomly chosen input channel, which has a value available for read.
    throws:
    InterruptedException If the current thread gets interrupted
    
    Returns:
    The read value. It will be of SelectResult type, holding the actual value as well as the channel index.
  - public final SelectResult<T> call(java.util.List<java.lang.Boolean> mask)
    
    Selects a value from a single randomly chosen input channel, which has a value available for read. Only the channels marked with 'true' in the supplied mask will be considered.
    throws:
    InterruptedException If the current thread gets interrupted
    
    Returns:
    The read value. It will be of SelectResult type, holding the actual value as well as the channel index.
    Parameters:
    mask - A list of boolean values indicating, whether the input channel with the same position index should be included in the selection or not
  - public final void call(MessageStream messageStream)
    
    Selects a value from a single randomly chosen input channel, which has a value available for read. The read value is send to the supplied messageStream
    throws:
    InterruptedException If the current thread gets interrupted
    
    Parameters:
    messageStream - A message stream accepting the selected value. The message will be of SelectResult type, holding the actual value as well as the channel index.
  - public final void call(MessageStream messageStream, java.util.List<java.lang.Boolean> mask)
    
    Selects a value from a single randomly chosen input channel, which has a value available for read. The read value is send to the supplied messageStream
    throws:
    InterruptedException If the current thread gets interrupted
    
    Parameters:
    messageStream - A message stream accepting the selected value. The message will be of SelectResult type, holding the actual value as well as the channel index.
    mask - A list of boolean values indicating, whether the input channel with the same position index should be included in the selection or not
  - public static DataflowReadChannel<java.lang.String> createTimeout(long timeout)
    
    Creates a timeout channel (DataflowVariable) that will bind a Select.TIMEOUT value after the specified timeout.
    Returns:
    A DataflowVariable instance that will have the Select.TIMEOUT value bound after the specified number of milliseconds elapse
    Parameters:
    timeout - The delay in milliseconds to wait before the value gets bound
  - public SelectResult<T> prioritySelect()
    
    Selects a value from a single input channel, which has a value available for read. Channels with lower position index are preferred.
    throws:
    InterruptedException If the current thread gets interrupted
    
    Returns:
    The read value. It will be of SelectResult type, holding the actual value as well as the channel index.
  - public SelectResult<T> prioritySelect(java.util.List<java.lang.Boolean> mask)
    
    Selects a value from a single input channel, which has a value available for read. Channels with lower position index are preferred. Only the channels marked with 'true' in the supplied mask will be considered.
    throws:
    InterruptedException If the current thread gets interrupted
    
    Returns:
    The read value. It will be of SelectResult type, holding the actual value as well as the channel index.
    Parameters:
    mask - A list of boolean values indicating, whether the input channel with the same position index should be included in the selection or not
  - public void prioritySelect(MessageStream messageStream)
    
    Selects a value from a single input channel, which has a value available for read. Channels with lower position index are preferred. The read value is send to the supplied messageStream
    throws:
    InterruptedException If the current thread gets interrupted
    
    Parameters:
    messageStream - A message stream accepting the selected value. The message will be of SelectResult type, holding the actual value as well as the channel index.
  - public void prioritySelect(MessageStream messageStream, java.util.List<java.lang.Boolean> mask)
    
    Selects a value from a single input channel, which has a value available for read. Channels with lower position index are preferred. The read value is send to the supplied messageStream
    throws:
    InterruptedException If the current thread gets interrupted
    
    Parameters:
    messageStream - A message stream accepting the selected value. The message will be of SelectResult type, holding the actual value as well as the channel index.
    mask - A list of boolean values indicating, whether the input channel with the same position index should be included in the selection or not
  - public Promise<SelectResult<T>> prioritySelectToPromise()
    
    Selects asynchronously a value from a single input channel, which has a value available for read. Channels with lower position index are preferred. The returned Promise will eventually get bound to the selected value (wrapped inside s SelectResult instance)
    throws:
    InterruptedException If the current thread gets interrupted
  - public Promise<SelectResult<T>> prioritySelectToPromise(java.util.List<java.lang.Boolean> mask)
    
    Selects asynchronously a value from a single input channel, which has a value available for read. Channels with lower position index are preferred. The returned Promise will eventually get bound to the selected value (wrapped inside s SelectResult instance)
    throws:
    InterruptedException If the current thread gets interrupted
    
    Parameters:
    mask - A list of boolean values indicating, whether the input channel with the same position index should be included in the selection or not
  - public SelectResult<T> select()
    
    Selects a value from a single randomly chosen input channel, which has a value available for read.
    throws:
    InterruptedException If the current thread gets interrupted
    
    Returns:
    The read value. It will be of SelectResult type, holding the actual value as well as the channel index.
  - public SelectResult<T> select(java.util.List<java.lang.Boolean> mask)
    
    Selects a value from a single randomly chosen input channel, which has a value available for read. Only the channels marked with 'true' in the supplied mask will be considered.
    throws:
    InterruptedException If the current thread gets interrupted
    
    Returns:
    The read value. It will be of SelectResult type, holding the actual value as well as the channel index.
    Parameters:
    mask - A list of boolean values indicating, whether the input channel with the same position index should be included in the selection or not
  - public void select(MessageStream messageStream)
    
    Selects a value from a single randomly chosen input channel, which has a value available for read. The read value is send to the supplied messageStream
    throws:
    InterruptedException If the current thread gets interrupted
    
    Parameters:
    messageStream - A message stream accepting the selected value. The message will be of SelectResult type, holding the actual value as well as the channel index.
  - public void select(MessageStream messageStream, java.util.List<java.lang.Boolean> mask)
    
    Selects a value from a single randomly chosen input channel, which has a value available for read. The read value is send to the supplied messageStream
    throws:
    InterruptedException If the current thread gets interrupted
    
    Parameters:
    messageStream - A message stream accepting the selected value. The message will be of SelectResult type, holding the actual value as well as the channel index.
    mask - A list of boolean values indicating, whether the input channel with the same position index should be included in the selection or not
  - private void select(MessageStream messageStream, int startIndex, java.util.List<java.lang.Boolean> mask)
    
    Invokes the internal select base with a SelectRequest instance ensuring a message is sent, once a value has been selected
  - private SelectResult<T> select(int startIndex, java.util.List<java.lang.Boolean> mask)
    
    Invokes the internal select base with a SelectRequest instance ensuring the current thread can continue returning the correct value, once a value has been selected
  - public Promise<SelectResult<T>> selectToPromise()
    
    Selects asynchronously a value from a single randomly chosen input channel, which has a value available for read. The returned Promise will eventually get bound to the selected value (wrapped inside s SelectResult instance)
    throws:
    InterruptedException If the current thread gets interrupted
  - public Promise<SelectResult<T>> selectToPromise(java.util.List<java.lang.Boolean> mask)
    
    /** Selects asynchronously a value from a single randomly chosen input channel, which has a value available for read. The returned Promise will eventually get bound to the selected value (wrapped inside s SelectResult instance)
    throws:
    InterruptedException If the current thread gets interrupted
    
    Parameters:
    mask - A list of boolean values indicating, whether the input channel with the same position index should be included in the selection or not
  - private Promise<SelectResult<T>> selectToPromise(int startIndex, java.util.List<java.lang.Boolean> mask)
    
    Invokes the internal select base with a SelectRequest instance ensuring a message is sent, once a value has been selected

Summary:
Field
Constructor
Method

| Detail:
Field
Constructor
Method

[Java] Class Select<T>

Field Summary

Constructor Summary

Methods Summary

Inherited Methods Summary

Field Detail

public static final java.lang.String TIMEOUT

private final SelectBase<T> selectBase

Constructor Detail

@java.lang.SuppressWarnings({"OverloadedVarargsMethod"}) public Select(PGroup pGroup, SelectableChannel<? extends T>... channels)

public Select(PGroup pGroup, java.util.List<SelectableChannel<? extends T>> channels)

Method Detail

public final SelectResult<T> call()

public final SelectResult<T> call(java.util.List<java.lang.Boolean> mask)

public final void call(MessageStream messageStream)

public final void call(MessageStream messageStream, java.util.List<java.lang.Boolean> mask)

public static DataflowReadChannel<java.lang.String> createTimeout(long timeout)

public SelectResult<T> prioritySelect()

public SelectResult<T> prioritySelect(java.util.List<java.lang.Boolean> mask)

public void prioritySelect(MessageStream messageStream)

public void prioritySelect(MessageStream messageStream, java.util.List<java.lang.Boolean> mask)

public Promise<SelectResult<T>> prioritySelectToPromise()

public Promise<SelectResult<T>> prioritySelectToPromise(java.util.List<java.lang.Boolean> mask)

public SelectResult<T> select()

public SelectResult<T> select(java.util.List<java.lang.Boolean> mask)

public void select(MessageStream messageStream)

public void select(MessageStream messageStream, java.util.List<java.lang.Boolean> mask)

private void select(MessageStream messageStream, int startIndex, java.util.List<java.lang.Boolean> mask)

private SelectResult<T> select(int startIndex, java.util.List<java.lang.Boolean> mask)

public Promise<SelectResult<T>> selectToPromise()

public Promise<SelectResult<T>> selectToPromise(java.util.List<java.lang.Boolean> mask)

private Promise<SelectResult<T>> selectToPromise(int startIndex, java.util.List<java.lang.Boolean> mask)