Class SemaphoreControlledChannel

    • Constructor Summary

      Constructors 
      Constructor Description
      SemaphoreControlledChannel​(int capacity)
      Create a channel with the given capacity and default semaphore implementation
      SemaphoreControlledChannel​(int capacity, java.lang.Class semaphoreClass)
      Create a channel with the given capacity and semaphore implementations instantiated from the supplied class
    • Method Summary

      All Methods Instance Methods Abstract Methods Concrete Methods 
      Modifier and Type Method Description
      int capacity()
      Return the maximum number of elements that can be held.
      protected abstract java.lang.Object extract()
      Internal mechanics of take.
      protected abstract void insert​(java.lang.Object x)
      Internal mechanics of put.
      boolean offer​(java.lang.Object x, long msecs)
      Place item in channel only if it can be accepted within msecs milliseconds.
      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
      • Methods inherited from interface EDU.oswego.cs.dl.util.concurrent.Channel

        peek
    • Field Detail

      • putGuard_

        protected final Semaphore putGuard_
      • takeGuard_

        protected final Semaphore takeGuard_
      • capacity_

        protected int capacity_
    • Constructor Detail

      • SemaphoreControlledChannel

        public SemaphoreControlledChannel​(int capacity)
                                   throws java.lang.IllegalArgumentException
        Create a channel with the given capacity and default semaphore implementation
        Throws:
        java.lang.IllegalArgumentException - if capacity less or equal to zero
      • SemaphoreControlledChannel

        public SemaphoreControlledChannel​(int capacity,
                                          java.lang.Class semaphoreClass)
                                   throws java.lang.IllegalArgumentException,
                                          java.lang.NoSuchMethodException,
                                          java.lang.SecurityException,
                                          java.lang.InstantiationException,
                                          java.lang.IllegalAccessException,
                                          java.lang.reflect.InvocationTargetException
        Create a channel with the given capacity and semaphore implementations instantiated from the supplied class
        Throws:
        java.lang.IllegalArgumentException - if capacity less or equal to zero.
        java.lang.NoSuchMethodException - If class does not have constructor that intializes permits
        java.lang.SecurityException - if constructor information not accessible
        java.lang.InstantiationException - if semaphore class is abstract
        java.lang.IllegalAccessException - if constructor cannot be called
        java.lang.reflect.InvocationTargetException - if semaphore constructor throws an exception
    • Method Detail

      • 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.
      • size

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

        protected abstract void insert​(java.lang.Object x)
        Internal mechanics of put.
      • extract

        protected abstract java.lang.Object extract()
        Internal mechanics of take.
      • 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).