Interface ChannelDataStoreInt

  • All Superinterfaces:
    java.lang.Cloneable
    All Known Implementing Classes:
    BufferInt, InfiniteBufferInt, OverFlowingBufferInt, OverWriteOldestBufferInt, OverWritingBufferInt, ZeroBufferInt

    public interface ChannelDataStoreInt
    extends java.lang.Cloneable
    This is the interface for integer channel plug-ins that define their buffering characteristics.

    Description

    ChannelDataStoreInt defines the interface to the logic used by the integer channels defined in the org.jcsp.lang package to manage the data being communicated.

    This enables that logic to be varied by creating channels specifying a particular implementation of this interface. This reduces the number of classes that would otherwise need to be defined. The default channel constructor (with no parameters) uses the ZeroBuffer implementation, which gives the standard CSP semantics -- no buffering and full synchronisation between reading and writing processes. See the static construction methods of Channel (Channel.one2oneInt(org.jcsp.util.ints.ChannelDataStoreInt) etc.).

    Note: instances of ChannelDataStoreInt implementations are used by the various channel classes within org.jcsp.lang in a thread-safe way. They are not intended for any other purpose. Developers of new ChannelDataStoreInt implementations, therefore, do not need to worry about thread safety (e.g. by making its methods synchronized). Also, developers can assume that the documented pre-conditions for invoking the get and put methods will be met.

    Author:
    P.D. Austin
    See Also:
    ZeroBufferInt, BufferInt, OverWriteOldestBufferInt, OverWritingBufferInt, OverFlowingBufferInt, InfiniteBufferInt, ChannelInt
    • Field Summary

      Fields 
      Modifier and Type Field Description
      static int EMPTY
      Indicates that the ChannelDataStoreInt is empty -- it can accept only a put.
      static int FULL
      Indicates that the ChannelDataStoreInt is full -- it can accept only a get.
      static int NONEMPTYFULL
      Indicates that the ChannelDataStoreInt is neither empty nor full -- it can accept either a put or a get call.
    • Method Summary

      All Methods Instance Methods Abstract Methods 
      Modifier and Type Method Description
      java.lang.Object clone()
      Returns a new (and EMPTY) ChannelDataStoreInt with the same creation parameters as this one.
      void endGet()
      Ends an extended read on the buffer.
      int get()
      Returns an int from the ChannelDataStoreInt.
      int getState()
      Returns the current state of the ChannelDataStoreInt.
      void put​(int value)
      Puts a new int into the ChannelDataStoreInt.
      void removeAll()  
      int startGet()
      Begins an extended read on the buffer, returning the data for the extended read Pre-condition: getState must not currently return EMPTY.
    • Field Detail

      • EMPTY

        static final int EMPTY
        Indicates that the ChannelDataStoreInt is empty -- it can accept only a put.
        See Also:
        Constant Field Values
      • NONEMPTYFULL

        static final int NONEMPTYFULL
        Indicates that the ChannelDataStoreInt is neither empty nor full -- it can accept either a put or a get call.
        See Also:
        Constant Field Values
      • FULL

        static final int FULL
        Indicates that the ChannelDataStoreInt is full -- it can accept only a get.
        See Also:
        Constant Field Values
    • Method Detail

      • getState

        int getState()
        Returns the current state of the ChannelDataStoreInt.
        Returns:
        the current state of the ChannelDataStoreInt (EMPTY, NONEMPTYFULL or FULL)
      • put

        void put​(int value)
        Puts a new int into the ChannelDataStoreInt.

        Pre-condition: getState must not currently return FULL.

        Parameters:
        value - the int to put into the ChannelDataStoreInt
      • get

        int get()
        Returns an int from the ChannelDataStoreInt.

        Pre-condition: getState must not currently return EMPTY.

        Returns:
        an int from the ChannelDataStoreInt
      • startGet

        int startGet()
        Begins an extended read on the buffer, returning the data for the extended read Pre-condition: getState must not currently return EMPTY. The exact behaviour of this method depends on your buffer. When a process performs an extended rendezvous on a buffered channel, it will first call this method, then the endGet() method. A FIFO buffer would implement this method as returning the value from the front of the buffer and the next call would remove the value. An overflowing buffer would do the same. However, for an overwriting buffer it is more complex. Refer to the documentation for OverWritingBuffer.startGet() and OverWriteOldestBuffer.startGet() for details
        Returns:
        The int to be read from the channel at the beginning of the extended rendezvous
        See Also:
        endGet()
      • endGet

        void endGet()
        Ends an extended read on the buffer. The channels guarantee that this method will be called exactly once after each beginExtRead call. During the period between startGet and endGet, it is possible that put(int) will be called, but not get().
        See Also:
        startGet()
      • clone

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

        Note: Only the size and structure of the ChannelDataStoreInt should be cloned, not any stored data.

        Returns:
        the cloned instance of this ChannelDataStoreInt.
      • removeAll

        void removeAll()