Package org.jcsp.lang

Class ChannelInputImpl<T>

java.lang.Object

org.jcsp.lang.ChannelInputImpl<T>

All Implemented Interfaces:

ChannelInput<T>, Poisonable

Direct Known Subclasses:

RejectableChannelInputImpl

class ChannelInputImpl<T>
extends java.lang.Object
implements ChannelInput<T>

Field Summary

Fields

Modifier and Type	Field	Description
private ChannelInternals<T>	channel
private int	immunity

Constructor Summary

Constructors

Constructor	Description
ChannelInputImpl(ChannelInternals _channel, int _immunity)

Method Summary

Modifier and Type	Method	Description
void	endRead()	End an extended rendezvous.
void	poison(int strength)	This injects poison into the channel.
T	read()	Read an Object from the channel.
T	startRead()	Begin an extended rendezvous read from the channel.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

channel

private ChannelInternals<T> channel

immunity

private int immunity

Constructor Detail

ChannelInputImpl

ChannelInputImpl(ChannelInternals _channel,
                 int _immunity)

Method Detail

endRead

public void endRead()

Description copied from interface: ChannelInput

End an extended rendezvous. It must be invoked once (and only once) following a startRead.

Specified by:

endRead in interface ChannelInput<T>

read

public T read()

Description copied from interface: ChannelInput

Read an Object from the channel.

Specified by:

read in interface ChannelInput<T>

Returns:

the object read from the channel

startRead

public T startRead()

Description copied from interface: ChannelInput

Begin an extended rendezvous read from the channel. An extended rendezvous is not completed until the reader has completed its extended action. This method starts an extended rendezvous. When a writer to this channel writes, this method returns what was sent immediately. The extended rendezvous continues with reader actions until the reader invokes endRead. Only then will the writer be released (from its write method). The writer is unaware of the extended nature of the communication.

The reader process must call endRead at some point after this function, otherwise the writer will not be freed and deadlock will probably follow.

The reader process may perform any actions between calling startRead and endRead, including communications on other channels. Further communications on this channel, of course, should not be made.

An extended rendezvous may be started after the channel's Guard has been selected by an Alternative (i.e. startRead instead of read).

Specified by:

startRead in interface ChannelInput<T>

Returns:

The object read from the channel

poison

public void poison(int strength)

Description copied from interface: Poisonable

This injects poison into the channel. If the channel was not explicitly constructed to be poisonable or if the strength of poison is not greater than the channel immunity level, the poison will have no effect.

Specified by:

poison in interface Poisonable

Parameters:

strength - the strength of the poison (must be >= 0).