Class PoisonableOne2OneChannelIntImpl

java.lang.Object
org.jcsp.lang.PoisonableOne2OneChannelIntImpl
All Implemented Interfaces:
ChannelInternalsInt, One2OneChannelInt
class PoisonableOne2OneChannelIntImpl extends Object implements One2OneChannelInt, ChannelInternalsInt

  • Field Details

    • rwMonitor

      private Object rwMonitor
      The monitor synchronising reader and writer on this channel

    • hold

      private int hold
      The (invisible-to-users) buffer used to store the data for the channel

    • empty

      private boolean empty
      The synchronisation flag

    • done

      private boolean done
      This flag indicates that the last transfer went OK. The purpose is to not throw a PoisonException to the writer side when the last transfer went OK, but the reader side injected poison before the writer side finished processing of the last write transfer.

    • poisonStrength

      private int poisonStrength
      0 means unpoisoned

    • immunity

      private int immunity
      Immunity is passed to the channel-ends, and is not used directly by the channel algorithms

    • alt

      private Alternative alt
      The Alternative class that controls the selection

    • spuriousWakeUp

      private boolean spuriousWakeUp
      Flag to deal with a spurious wakeup during a write

  • Constructor Details

    • PoisonableOne2OneChannelIntImpl

      PoisonableOne2OneChannelIntImpl(int _immunity)

  • Method Details

    • isPoisoned

      private boolean isPoisoned()

    • in

      public AltingChannelInputInt in()
      Returns the AltingChannelInput to use for this channel. As One2OneChannelImpl implements AltingChannelInput itself, this method simply returns a reference to the object that it is called on.
      Specified by:
      in in interface One2OneChannelInt
      Returns:
      the AltingChannelInput object to use for this channel.

    • out

      public ChannelOutputInt out()
      Returns the ChannelOutput object to use for this channel. As One2OneChannelImpl implements ChannelOutput itself, this method simply returns a reference to the object that it is called on.
      Specified by:
      out in interface One2OneChannelInt
      Returns:
      the ChannelOutput object to use for this channel.

    • write

      public void write(int value)
      Writes an Object to the channel.
      Specified by:
      write in interface ChannelInternalsInt
      Parameters:
      value - the object to write to the channel.

    • read

      public int read()
      Reads an Object from the channel.
      Specified by:
      read in interface ChannelInternalsInt
      Returns:
      the object read from the channel.

    • startRead

      public int startRead()
      Specified by:
      startRead in interface ChannelInternalsInt

    • endRead

      public void endRead()
      Specified by:
      endRead in interface ChannelInternalsInt

    • readerEnable

      public boolean readerEnable(Alternative alt)
      turns on Alternative selection for the channel. Returns true if the channel has data that can be read immediately.

      Note: this method should only be called by the Alternative class

      Specified by:
      readerEnable in interface ChannelInternalsInt
      Parameters:
      alt - the Alternative class which will control the selection
      Returns:
      true if the channel has data that can be read, else false

    • readerDisable

      public boolean readerDisable()
      turns off Alternative selection for the channel. Returns true if the channel contained data that can be read.

      Note: this method should only be called by the Alternative class

      Specified by:
      readerDisable in interface ChannelInternalsInt
      Returns:
      true if the channel has data that can be read, else false

    • readerPending

      public boolean readerPending()
      Returns whether there is data pending on this channel.

      Note: if there is, it won't go away until you read it. But if there isn't, there may be some by the time you check the result of this method.

      This method is provided for convenience. Its functionality can be provided by Pri Alting the channel against a SKIP guard, although at greater run-time and syntactic cost. For example, the following code fragment: 

        if (c.pending ()) {
    Object x = c.read ();
    ...  do something with x
  } else (
    ...  do something else
  }
      is equivalent to: 
        if (c_pending.priSelect () == 0) {
    Object x = c.read ();
    ...  do something with x
  } else (
    ...  do something else
}
      where earlier would have had to have been declared: 
      final Alternative c_pending =
  new Alternative (new Guard[] {c, new Skip ()});
      Specified by:
      readerPending in interface ChannelInternalsInt
      Returns:
      state of the channel.

    • writerPoison

      public void writerPoison(int strength)
      Specified by:
      writerPoison in interface ChannelInternalsInt

    • readerPoison

      public void readerPoison(int strength)
      Specified by:
      readerPoison in interface ChannelInternalsInt