Package org.jcsp.util

Class ZeroBuffer

  • All Implemented Interfaces:
    java.io.Serializable, java.lang.Cloneable, ChannelDataStore

    public class ZeroBuffer
    extends java.lang.Object
    implements ChannelDataStore, java.io.Serializable
    This is used to create a zero-buffered object channel that never loses data.

    Description

    ZeroBuffer is an implementation of ChannelDataStore that yields the standard CSP semantics for a channel -- that is zero buffered with direct synchronisation between reader and writer. Unless specified otherwise, this is the default behaviour for channels. See the static construction methods of Channel (Channel.one2one(org.jcsp.util.ChannelDataStore) etc.).

    The getState method will return FULL if there is an output waiting on the channel and EMPTY if there is not.

    Author:
    P.D. Austin
    See Also:
    Buffer, OverWriteOldestBuffer, OverWritingBuffer, OverFlowingBuffer, InfiniteBuffer, One2OneChannelImpl, Any2OneChannelImpl, One2AnyChannelImpl, Any2AnyChannelImpl, Serialized Form
    • Constructor Summary

      Constructors 
      Constructor Description
      ZeroBuffer()  
    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      java.lang.Object clone()
      Returns a new (and EMPTY) ZeroBuffer with the same creation parameters as this one.
      void endGet()
      Ends the extended rendezvous by clearing the buffer.
      java.lang.Object get()
      Returns the Object from the ZeroBuffer.
      int getState()
      Returns the current state of the ZeroBuffer.
      void put​(java.lang.Object value)
      Puts a new Object into the ZeroBuffer.
      void removeAll()
      Deletes all items in the buffer, leaving it empty.
      java.lang.Object startGet()
      Begins an extended rendezvous - simply returns the next object in the buffer.
      • Methods inherited from class java.lang.Object

        equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Constructor Detail

      • ZeroBuffer

        public ZeroBuffer()
    • Method Detail

      • get

        public java.lang.Object get()
        Returns the Object from the ZeroBuffer.

        Pre-condition: getState must not currently return EMPTY.

        Specified by:
        get in interface ChannelDataStore
        Returns:
        the Object from the ZeroBuffer
      • startGet

        public java.lang.Object startGet()
        Begins an extended rendezvous - simply returns the next object in the buffer. This function does not remove the object. Pre-condition: getState must not currently return EMPTY.
        Specified by:
        startGet in interface ChannelDataStore
        Returns:
        The object in the buffer.
        See Also:
        ChannelDataStore.endGet()
      • put

        public void put​(java.lang.Object value)
        Puts a new Object into the ZeroBuffer.

        Pre-condition: getState must not currently return FULL.

        Specified by:
        put in interface ChannelDataStore
        Parameters:
        value - the Object to put into the ZeroBuffer
      • getState

        public int getState()
        Returns the current state of the ZeroBuffer.
        Specified by:
        getState in interface ChannelDataStore
        Returns:
        the current state of the ZeroBuffer (EMPTY or FULL)
      • clone

        public java.lang.Object clone()
        Returns a new (and EMPTY) ZeroBuffer with the same creation parameters as this one.

        Note: Only the size and structure of the ZeroBuffer is cloned, not any stored data.

        Specified by:
        clone in interface ChannelDataStore
        Overrides:
        clone in class java.lang.Object
        Returns:
        the cloned instance of this ZeroBuffer.