Package kilim

Class Mailbox<T>

java.lang.Object
kilim.Mailbox<T>
All Implemented Interfaces:
EventPublisher, PauseReason
public class Mailbox<T> extends Object implements PauseReason, EventPublisher
This is a typed buffer that supports multiple producers and a single consumer. It is the basic construct used for tasks to interact and synchronize with each other (as opposed to direct java calls or static member variables). put() and get() are the two essential functions. We use the term "block" to mean thread block, and "pause" to mean fiber pausing. The suffix "nb" on some methods (such as getnb()) stands for non-blocking. Both put() and get() have blocking and non-blocking variants in the form of putb(), putnb

  • Field Details

    • msgs

      T[] msgs

    • iprod

      private int iprod

    • icons

      private int icons

    • numMsgs

      private int numMsgs

    • maxMsgs

      private int maxMsgs

    • sink

      EventSubscriber sink

    • SPACE_AVAILABLE

      public static final int SPACE_AVAILABLE
      See Also:

    • MSG_AVAILABLE

      public static final int MSG_AVAILABLE
      See Also:

    • TIMED_OUT

      public static final int TIMED_OUT
      See Also:

    • spaceAvailble

      public static final Event spaceAvailble

    • messageAvailable

      public static final Event messageAvailable

    • timedOut

      public static final Event timedOut

    • srcs

      LinkedList<EventSubscriber> srcs

  • Constructor Details

    • Mailbox

      public Mailbox()

    • Mailbox

      public Mailbox(int initialSize)

    • Mailbox

      public Mailbox(int initialSize, int maxSize)

  • Method Details

    • get

      public T get(EventSubscriber eo)
      Non-blocking, nonpausing get.
      Parameters:
      eo - . If non-null, registers this observer and calls it with a MessageAvailable event when a put() is done.
      Returns:
      buffered message if there's one, or null

    • put

      public boolean put(T msg, EventSubscriber eo)
      Non-blocking, nonpausing put.
      Parameters:
      eo - . If non-null, registers this observer and calls it with an SpaceAvailable event when there's space.
      Returns:
      buffered message if there's one, or null
      See Also:

    • getnb

      public T getnb()
      Get, don't pause or block.
      Returns:
      stored message, or null if no message found.

    • get

      public T get() throws Pausable
      Returns:
      non-null message.
      Throws:
      Pausable

    • get

      public T get(long timeoutMillis) throws Pausable
      Returns:
      non-null message, or null if timed out.
      Throws:
      Pausable

    • untilHasMessage

      public void untilHasMessage() throws Pausable
      Block caller until at least one message is available.
      Throws:
      Pausable

    • untilHasMessages

      public void untilHasMessages(int num) throws Pausable
      Block caller until num messages are available.
      Parameters:
      num -
      Throws:
      Pausable

    • hasMessage

      public boolean hasMessage(Task eo)

    • hasMessages

      public boolean hasMessages(int num, Task eo)

    • peek

      public T peek(int idx)

    • remove

      public T remove(int idx)

    • messages

      public Object[] messages()

    • select

      public static int select(Mailbox... mboxes) throws Pausable
      Takes an array of mailboxes and returns the index of the first mailbox that has a message. It is possible that because of race conditions, an earlier mailbox in the list may also have received a message.
      Throws:
      Pausable

    • addSpaceAvailableListener

      public void addSpaceAvailableListener(EventSubscriber spcSub)

    • removeSpaceAvailableListener

      public void removeSpaceAvailableListener(EventSubscriber spcSub)

    • addMsgAvailableListener

      public void addMsgAvailableListener(EventSubscriber msgSub)

    • removeMsgAvailableListener

      public void removeMsgAvailableListener(EventSubscriber msgSub)

    • putnb

      public boolean putnb(T msg)
      Attempt to put a message, and return true if successful. The thread is not blocked, nor is the task paused under any circumstance.

    • put

      public void put(T msg) throws Pausable
      put a non-null message in the mailbox, and pause the calling task until the mailbox has space
      Throws:
      Pausable

    • put

      public boolean put(T msg, int timeoutMillis) throws Pausable
      put a non-null message in the mailbox, and pause the calling task for timeoutMillis if the mailbox is full.
      Throws:
      Pausable

    • putb

      public void putb(T msg)

    • putb

      public boolean putb(T msg, long timeoutMillis)
      put a non-null message in the mailbox, and block the calling thread for timeoutMillis if the mailbox is full
      Returns:
      true if the message was successfully put in the mailbox

    • size

      public int size()

    • hasMessage

      public boolean hasMessage()

    • hasSpace

      public boolean hasSpace()

    • getb

      public T getb()
      retrieve a message, blocking the thread indefinitely. Note, this is a heavyweight block, unlike #get() that pauses the Fiber but doesn't block the thread.

    • getb

      public T getb(long timeoutMillis)
      retrieve a msg, and block the Java thread for the time given.
      Parameters:
      millis - . max wait time
      Returns:
      null if timed out.

    • toString

      public String toString()
      Overrides:
      toString in class Object

    • isValid

      public boolean isValid(Task t)
      Description copied from interface: PauseReason
      True if the given task's reason for pausing is still valid.
      Specified by:
      isValid in interface PauseReason