Class BoundedBuffer

java.lang.Object
EDU.oswego.cs.dl.util.concurrent.BoundedBuffer
All Implemented Interfaces:
BoundedChannel, Channel, Puttable, Takable

public class BoundedBuffer extends Object implements BoundedChannel
Efficient array-based bounded buffer class. Adapted from CPJ, chapter 8, which describes design.

[ Introduction to this package. ]

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    protected final Object[]
     
    protected int
     
    protected final Object
    Helper monitor to handle puts.
    protected int
     
    protected int
     
    protected int
     
  • Constructor Summary

    Constructors
    Constructor
    Description
    Create a buffer with the current default capacity
    BoundedBuffer(int capacity)
    Create a BoundedBuffer with the given capacity.
  • Method Summary

    Modifier and Type
    Method
    Description
    int
    Return the maximum number of elements that can be held.
    protected final Object
     
    protected void
     
    protected void
     
    protected final void
     
    boolean
    offer(Object x, long msecs)
    Place item in channel only if it can be accepted within msecs milliseconds.
    Return, but do not remove object at head of Channel, or null if it is empty.
    poll(long msecs)
    Return and remove an item from channel only if one is available within msecs milliseconds.
    void
    Place item in the channel, possibly waiting indefinitely until it can be accepted.
    int
    Return the number of elements in the buffer.
    Return and remove an item from channel, possibly waiting indefinitely until such an item exists.

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
  • Field Details

    • array_

      protected final Object[] array_
    • takePtr_

      protected int takePtr_
    • putPtr_

      protected int putPtr_
    • usedSlots_

      protected int usedSlots_
    • emptySlots_

      protected int emptySlots_
    • putMonitor_

      protected final Object putMonitor_
      Helper monitor to handle puts.
  • Constructor Details

    • BoundedBuffer

      public BoundedBuffer(int capacity) throws IllegalArgumentException
      Create a BoundedBuffer with the given capacity.
      Throws:
      IllegalArgumentException - if capacity less or equal to zero
    • BoundedBuffer

      public BoundedBuffer()
      Create a buffer with the current default capacity
  • Method Details

    • size

      public int size()
      Return the number of elements in the buffer. This is only a snapshot value, that may change immediately after returning.
    • capacity

      public int capacity()
      Description copied from interface: BoundedChannel
      Return the maximum number of elements that can be held.
      Specified by:
      capacity in interface BoundedChannel
      Returns:
      the capacity of this channel.
    • incEmptySlots

      protected void incEmptySlots()
    • incUsedSlots

      protected void incUsedSlots()
    • insert

      protected final void insert(Object x)
    • extract

      protected final Object extract()
    • peek

      public Object peek()
      Description copied from interface: Channel
      Return, but do not remove object at head of Channel, or null if it is empty.
      Specified by:
      peek in interface Channel
    • put

      public void put(Object x) throws InterruptedException
      Description copied from interface: Channel
      Place item in the channel, possibly waiting indefinitely until it can be accepted. Channels implementing the BoundedChannel subinterface are generally guaranteed to block on puts upon reaching capacity, but other implementations may or may not block.
      Specified by:
      put in interface Channel
      Specified by:
      put in interface Puttable
      Parameters:
      x - the element to be inserted. Should be non-null.
      Throws:
      InterruptedException - if the current thread has been interrupted at a point at which interruption is detected, in which case the element is guaranteed not to be inserted. Otherwise, on normal return, the element is guaranteed to have been inserted.
    • offer

      public boolean offer(Object x, long msecs) throws InterruptedException
      Description copied from interface: Channel
      Place item in channel only if it can be accepted within msecs milliseconds. The time bound is interpreted in a coarse-grained, best-effort fashion.
      Specified by:
      offer in interface Channel
      Specified by:
      offer in interface Puttable
      Parameters:
      x - the element to be inserted. Should be non-null.
      msecs - the number of milliseconds to wait. If less than or equal to zero, the method does not perform any timed waits, but might still require access to a synchronization lock, which can impose unbounded delay if there is a lot of contention for the channel.
      Returns:
      true if accepted, else false
      Throws:
      InterruptedException - if the current thread has been interrupted at a point at which interruption is detected, in which case the element is guaranteed not to be inserted (i.e., is equivalent to a false return).
    • take

      public Object take() throws InterruptedException
      Description copied from interface: Channel
      Return and remove an item from channel, possibly waiting indefinitely until such an item exists.
      Specified by:
      take in interface Channel
      Specified by:
      take in interface Takable
      Returns:
      some item from the channel. Different implementations may guarantee various properties (such as FIFO) about that item
      Throws:
      InterruptedException - if the current thread has been interrupted at a point at which interruption is detected, in which case state of the channel is unchanged.
    • poll

      public Object poll(long msecs) throws InterruptedException
      Description copied from interface: Channel
      Return and remove an item from channel only if one is available within msecs milliseconds. The time bound is interpreted in a coarse grained, best-effort fashion.
      Specified by:
      poll in interface Channel
      Specified by:
      poll in interface Takable
      Parameters:
      msecs - the number of milliseconds to wait. If less than or equal to zero, the operation does not perform any timed waits, but might still require access to a synchronization lock, which can impose unbounded delay if there is a lot of contention for the channel.
      Returns:
      some item, or null if the channel is empty.
      Throws:
      InterruptedException - if the current thread has been interrupted at a point at which interruption is detected, in which case state of the channel is unchanged (i.e., equivalent to a null return).