Package Summary  Overview Summary

class:SynchronousQueue [CHANGED]

  • Type Parameters:
    E - the type of elements held in this collectionqueue
    All Implemented Interfaces:
    Serializable, Iterable<E>, Collection<E>, BlockingQueue<E>, Queue<E>


    public class SynchronousQueue<E>
    extends AbstractQueue<E>
    implements BlockingQueue<E>, Serializable
    
    A blocking queue in which each insert operation must wait for a corresponding remove operation by another thread, and vice versa. A synchronous queue does not have any internal capacity, not even a capacity of one. You cannot peek at a synchronous queue because an element is only present when you try to remove it; you cannot insert an element (using any method) unless another thread is trying to remove it; you cannot iterate as there is nothing to iterate. The head of the queue is the element that the first queued inserting thread is trying to add to the queue; if there is no such queued thread then no element is available for removal and poll() will return null. For purposes of other Collection methods (for example contains), a SynchronousQueue acts as an empty collection. This queue does not permit null elements.

    Synchronous queues are similar to rendezvous channels used in CSP and Ada. They are well suited for handoff designs, in which an object running in one thread must sync up with an object running in another thread in order to hand it some information, event, or task.

    This class supports an optional fairness policy for ordering waiting producer and consumer threads. By default, this ordering is not guaranteed. However, a queue constructed with fairness set to true grants threads access in FIFO order.

    This class and its iterator implement all of the optional methods of the Collection and Iterator interfaces.

    This class is a member of the Java Collections Framework .

    Since:
    1.5
    See Also:
    Serialized Form
  • Type Parameters:
    E - the type of elements held in this collection
    All Implemented Interfaces:
    Serializable, Iterable<E>, Collection<E>, BlockingQueue<E>, Queue<E>


    public class SynchronousQueue<E>
    extends AbstractQueue<E>
    implements BlockingQueue<E>, Serializable
    
    A blocking queue in which each insert operation must wait for a corresponding remove operation by another thread, and vice versa. A synchronous queue does not have any internal capacity, not even a capacity of one. You cannot peek at a synchronous queue because an element is only present when you try to remove it; you cannot insert an element (using any method) unless another thread is trying to remove it; you cannot iterate as there is nothing to iterate. The head of the queue is the element that the first queued inserting thread is trying to add to the queue; if there is no such queued thread then no element is available for removal and poll() will return null. For purposes of other Collection methods (for example contains), a SynchronousQueue acts as an empty collection. This queue does not permit null elements.

    Synchronous queues are similar to rendezvous channels used in CSP and Ada. They are well suited for handoff designs, in which an object running in one thread must sync up with an object running in another thread in order to hand it some information, event, or task.

    This class supports an optional fairness policy for ordering waiting producer and consumer threads. By default, this ordering is not guaranteed. However, a queue constructed with fairness set to true grants threads access in FIFO order.

    This class and its iterator implement all of the optional methods of the Collection and Iterator interfaces.

    This class is a member of the Java Collections Framework .

    Since:
    1.5
    See Also:
    Serialized Form
  • Type Parameters:
    E - the type of elements held in this queue
    All Implemented Interfaces:
    Serializable, Iterable<E>, Collection<E>, BlockingQueue<E>, Queue<E>


    public class SynchronousQueue<E>
    extends AbstractQueue<E>
    implements BlockingQueue<E>, Serializable
    
    A blocking queue in which each insert operation must wait for a corresponding remove operation by another thread, and vice versa. A synchronous queue does not have any internal capacity, not even a capacity of one. You cannot peek at a synchronous queue because an element is only present when you try to remove it; you cannot insert an element (using any method) unless another thread is trying to remove it; you cannot iterate as there is nothing to iterate. The head of the queue is the element that the first queued inserting thread is trying to add to the queue; if there is no such queued thread then no element is available for removal and poll() will return null. For purposes of other Collection methods (for example contains), a SynchronousQueue acts as an empty collection. This queue does not permit null elements.

    Synchronous queues are similar to rendezvous channels used in CSP and Ada. They are well suited for handoff designs, in which an object running in one thread must sync up with an object running in another thread in order to hand it some information, event, or task.

    This class supports an optional fairness policy for ordering waiting producer and consumer threads. By default, this ordering is not guaranteed. However, a queue constructed with fairness set to true grants threads access in FIFO order.

    This class and its iterator implement all of the optional methods of the Collection and Iterator interfaces.

    This class is a member of the Java Collections Framework .

    Since:
    1.5
    See Also:
    Serialized Form

constructor:SynchronousQueue() [NONE]

  • SynchronousQueue

    public SynchronousQueue()
    Creates a SynchronousQueue with nonfair access policy.

constructor:SynchronousQueue(boolean) [NONE]

  • SynchronousQueue

    public SynchronousQueue(boolean fair)
    Creates a SynchronousQueue with the specified fairness policy.
    Parameters:
    fair - if true, waiting threads contend in FIFO order for access; otherwise the order is unspecified.

method:put(E) [NONE]

method:offer(E, long, java.util.concurrent.TimeUnit) [NONE]

  • offer

    public boolean offer(E e,
                         long timeout,
                         TimeUnit unit)
                  throws InterruptedException
    
    Inserts the specified element into this queue, waiting if necessary up to the specified wait time for another thread to receive it.
    Specified by:
    offer in interface BlockingQueue<E>
    Parameters:
    e - the element to add
    timeout - how long to wait before giving up, in units of unit
    unit - a TimeUnit determining how to interpret the timeout parameter
    Returns:
    true if successful, or false if the specified waiting time elapses before a consumer appears
    Throws:
    InterruptedException - if interrupted while waiting
    NullPointerException - if the specified element is null

method:offer(E) [NONE]

  • offer

    public boolean offer(E e)
    Inserts the specified element into this queue, if another thread is waiting to receive it.
    Specified by:
    offer in interface BlockingQueue<E>
    Specified by:
    offer in interface Queue<E>
    Parameters:
    e - the element to add
    Returns:
    true if the element was added to this queue, else false
    Throws:
    NullPointerException - if the specified element is null

method:take() [NONE]

  • take

    public E take()
           throws InterruptedException
    
    Retrieves and removes the head of this queue, waiting if necessary for another thread to insert it.
    Specified by:
    take in interface BlockingQueue<E>
    Returns:
    the head of this queue
    Throws:
    InterruptedException - if interrupted while waiting

method:poll(long, java.util.concurrent.TimeUnit) [NONE]

  • poll

    public E poll(long timeout,
                  TimeUnit unit)
           throws InterruptedException
    
    Retrieves and removes the head of this queue, waiting if necessary up to the specified wait time, for another thread to insert it.
    Specified by:
    poll in interface BlockingQueue<E>
    Parameters:
    timeout - how long to wait before giving up, in units of unit
    unit - a TimeUnit determining how to interpret the timeout parameter
    Returns:
    the head of this queue, or null if the specified waiting time elapses before an element is present
    Throws:
    InterruptedException - if interrupted while waiting

method:poll() [NONE]

  • poll

    public E poll()
    Retrieves and removes the head of this queue, if another thread is currently making an element available.
    Specified by:
    poll in interface Queue<E>
    Returns:
    the head of this queue, or null if no element is available

method:isEmpty() [NONE]

method:size() [NONE]

  • size

    public int size()
    Always returns zero. A SynchronousQueue has no internal capacity.
    Specified by:
    size in interface Collection<E>
    Specified by:
    size in class AbstractCollection<E>
    Returns:
    zero

method:remainingCapacity() [NONE]

  • remainingCapacity

    public int remainingCapacity()
    Always returns zero. A SynchronousQueue has no internal capacity.
    Specified by:
    remainingCapacity in interface BlockingQueue<E>
    Returns:
    zero

method:clear() [NONE]

  • clear

    public void clear()
    Does nothing. A SynchronousQueue has no internal capacity.
    Specified by:
    clear in interface Collection<E>
    Overrides:
    clear in class AbstractQueue<E>

method:contains(java.lang.Object) [CHANGED]

method:remove(java.lang.Object) [CHANGED]

  • remove

    public boolean remove(Object o)
    Always returns false. A SynchronousQueue has no internal capacity.
    Specified by:
    remove in interface CollectionBlockingQueue<E>
    Specified by:
    remove in interface BlockingQueueCollection<E>
    Overrides:
    remove in class AbstractCollection<E>
    Parameters:
    o - the element to remove
    Returns:
    false

method:containsAll(java.util.Collection) [NONE]

method:removeAll(java.util.Collection) [NONE]

method:retainAll(java.util.Collection) [NONE]

method:peek() [NONE]

  • peek

    public E peek()
    Always returns null. A SynchronousQueue does not return elements unless actively waited on.
    Specified by:
    peek in interface Queue<E>
    Returns:
    null

method:iterator() [CHANGED]

method:spliterator() [CHANGED]

method:toArray() [NONE]

method:toArray(T[]) [CHANGED]

  • toArray

    public <T> T[] toArray(T[] a)
    Sets the zeroethzeroth element of the specified array to null (if the array has non-zero length) and returns it.
    Specified by:
    toArray in interface Collection<E>
    Overrides:
    toArray in class AbstractCollection<E>
    Type Parameters:
    T - the runtime type of the array to contain the collection
    Parameters:
    a - the array
    Returns:
    the specified array
    Throws:
    NullPointerException - if the specified array is null
  • toArray

    public <T> T[] toArray(T[] a)
    Sets the zeroeth element of the specified array to null (if the array has non-zero length) and returns it.
    Specified by:
    toArray in interface Collection<E>
    Overrides:
    toArray in class AbstractCollection<E>
    Type Parameters:
    T - the runtime type of the array to contain the collection
    Parameters:
    a - the array
    Returns:
    the specified array
    Throws:
    NullPointerException - if the specified array is null
  • toArray

    public <T> T[] toArray(T[] a)
    Sets the zeroth element of the specified array to null (if the array has non-zero length) and returns it.
    Specified by:
    toArray in interface Collection<E>
    Overrides:
    toArray in class AbstractCollection<E>
    Type Parameters:
    T - the runtime type of the array to contain the collection
    Parameters:
    a - the array
    Returns:
    the specified array
    Throws:
    NullPointerException - if the specified array is null

method:toString() [ADDED]

method:drainTo(java.util.Collection) [NONE]

  • drainTo

    public int drainTo(Collection<? super E> c)
    Description copied from interface: BlockingQueue
    Removes all available elements from this queue and adds them to the given collection. This operation may be more efficient than repeatedly polling this queue. A failure encountered while attempting to add elements to collection c may result in elements being in neither, either or both collections when the associated exception is thrown. Attempts to drain a queue to itself result in IllegalArgumentException. Further, the behavior of this operation is undefined if the specified collection is modified while the operation is in progress.
    Specified by:
    drainTo in interface BlockingQueue<E>
    Parameters:
    c - the collection to transfer elements into
    Returns:
    the number of elements transferred
    Throws:
    UnsupportedOperationException - if addition of elements is not supported by the specified collection
    ClassCastException - if the class of an element of this queue prevents it from being added to the specified collection
    NullPointerException - if the specified collection is null
    IllegalArgumentException - if the specified collection is this queue, or some property of an element of this queue prevents it from being added to the specified collection

method:drainTo(java.util.Collection, int) [NONE]

  • drainTo

    public int drainTo(Collection<? super E> c,
                       int maxElements)
    Description copied from interface: BlockingQueue
    Removes at most the given number of available elements from this queue and adds them to the given collection. A failure encountered while attempting to add elements to collection c may result in elements being in neither, either or both collections when the associated exception is thrown. Attempts to drain a queue to itself result in IllegalArgumentException. Further, the behavior of this operation is undefined if the specified collection is modified while the operation is in progress.
    Specified by:
    drainTo in interface BlockingQueue<E>
    Parameters:
    c - the collection to transfer elements into
    maxElements - the maximum number of elements to transfer
    Returns:
    the number of elements transferred
    Throws:
    UnsupportedOperationException - if addition of elements is not supported by the specified collection
    ClassCastException - if the class of an element of this queue prevents it from being added to the specified collection
    NullPointerException - if the specified collection is null
    IllegalArgumentException - if the specified collection is this queue, or some property of an element of this queue prevents it from being added to the specified collection

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