Package org.jcsp.util

Class ZeroBuffer

java.lang.Object
org.jcsp.util.ZeroBuffer
All Implemented Interfaces:
Serializable, Cloneable, ChannelDataStore

public class ZeroBuffer extends Object implements ChannelDataStore, 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:
  • Constructor Details

    • ZeroBuffer

      public ZeroBuffer()
  • Method Details

    • get

      public 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 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:
    • endGet

      public void endGet()
      Ends the extended rendezvous by clearing the buffer.
      Specified by:
      endGet in interface ChannelDataStore
      See Also:
    • put

      public void put(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 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 Object
      Returns:
      the cloned instance of this ZeroBuffer.
    • removeAll

      public void removeAll()
      Description copied from interface: ChannelDataStore
      Deletes all items in the buffer, leaving it empty.
      Specified by:
      removeAll in interface ChannelDataStore