Package EDU.oswego.cs.dl.util.concurrent

Class BoundedBuffer

    • Field Summary

      Fields 
      Modifier and Type Field Description
      protected java.lang.Object[] array_  
      protected int emptySlots_  
      protected java.lang.Object putMonitor_
      Helper monitor to handle puts.
      protected int putPtr_  
      protected int takePtr_  
      protected int usedSlots_  

    • Constructor Summary

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

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      int capacity()
      Return the maximum number of elements that can be held.
      protected java.lang.Object extract()  
      protected void incEmptySlots()  
      protected void incUsedSlots()  
      protected void insert​(java.lang.Object x)  
      boolean offer​(java.lang.Object x, long msecs)
      Place item in channel only if it can be accepted within msecs milliseconds.
      java.lang.Object peek()
      Return, but do not remove object at head of Channel, or null if it is empty.
      java.lang.Object poll​(long msecs)
      Return and remove an item from channel only if one is available within msecs milliseconds.
      void put​(java.lang.Object x)
      Place item in the channel, possibly waiting indefinitely until it can be accepted.
      int size()
      Return the number of elements in the buffer.
      java.lang.Object take()
      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 Detail

      • array_

        protected final java.lang.Object[] array_

      • takePtr_

        protected int takePtr_

      • putPtr_

        protected int putPtr_

      • usedSlots_

        protected int usedSlots_

      • emptySlots_

        protected int emptySlots_

      • putMonitor_

        protected final java.lang.Object putMonitor_
        Helper monitor to handle puts.

    • Constructor Detail

      • BoundedBuffer

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

      • BoundedBuffer

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

    • Method Detail

      • 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​(java.lang.Object x)

      • extract

        protected final java.lang.Object extract()

      • peek

        public java.lang.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​(java.lang.Object x)
         throws java.lang.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:
        java.lang.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​(java.lang.Object x,
                     long msecs)
              throws java.lang.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:
        java.lang.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 java.lang.Object take()
                      throws java.lang.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:
        java.lang.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 java.lang.Object poll​(long msecs)
                      throws java.lang.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:
        java.lang.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).