Package org.apache.ignite

Interface IgniteCountDownLatch

  • All Superinterfaces:
    AutoCloseable, Closeable
    public interface IgniteCountDownLatch
extends Closeable
    This interface provides a rich API for working with distributed count down latch.

    Functionality

    Distributed count down latch provides functionality similar to java.util.CountDownLatch. Note that you cannot remove count down latch having count greater that zero. It should be counted down to zero first.

    Creating Distributed Count Down Latch

    Instance of cache count down latch can be created by calling the following method: Ignite.countDownLatch(String, int, boolean, boolean).

    • Method Summary

      All Methods Instance Methods Abstract Methods 
      Modifier and Type Method Description
      boolean autoDelete()
      Gets autoDelete flag.
      void await()
      Causes the current thread to wait until the latch has counted down to zero, unless current thread is interrupted.
      boolean await​(long timeout)
      Causes the current thread to wait until the latch has counted down to zero, unless the thread is interrupted, or the specified waiting time elapses.
      boolean await​(long timeout, TimeUnit unit)
      Causes the current thread to wait until the latch has counted down to zero, unless the thread is interrupted, or the specified waiting time elapses.
      void close()
      Removes this count down latch.
      int count()
      Gets current count value of the latch.
      int countDown()
      Decrements the count of the latch, releasing all waiting threads on all nodes if the count reaches zero.
      int countDown​(int val)
      Decreases the count of the latch using passed in value, releasing all waiting threads on all nodes if the count reaches zero.
      void countDownAll()
      Counts down this latch to zero, releasing all waiting threads on all nodes.
      int initialCount()
      Gets initial count value of the latch.
      String name()
      Gets name of the latch.
      boolean removed()
      Gets removed status of the latch.

    • Method Detail

      • name

        String name()
        Gets name of the latch.
        Returns:
        Name of the latch.

      • count

        int count()
        Gets current count value of the latch.
        Returns:
        Current count.

      • initialCount

        int initialCount()
        Gets initial count value of the latch.
        Returns:
        Initial count.

      • autoDelete

        boolean autoDelete()
        Gets autoDelete flag. If this flag is true latch is removed from cache when it has been counted down to 0.
        Returns:
        Value of autoDelete flag.

      • await

        void await()
    throws IgniteException
        Causes the current thread to wait until the latch has counted down to zero, unless current thread is interrupted.

        If the current count of the latch is zero then this method returns immediately.

        If the current count is greater than zero then the current thread becomes disabled for thread scheduling purposes and lies dormant until one of two things happen:

        • The count reaches zero due to invocations of the countDown() method on any node; or
        • Some other thread interrupts the current thread.

        If the current thread:

        • has its interrupted status set on entry to this method; or
        • is interrupted while waiting,
        then IgniteInterruptedCheckedException is thrown and the current thread's interrupted status is cleared.
        Throws:
        IgniteException - If operation failed.
        IgniteInterruptedException - if the current thread is interrupted while waiting

      • await

        boolean await​(long timeout)
       throws IgniteException
        Causes the current thread to wait until the latch has counted down to zero, unless the thread is interrupted, or the specified waiting time elapses.

        If the current count is zero then this method returns immediately with the value true.

        If the current count is greater than zero then the current thread becomes disabled for thread scheduling purposes and lies dormant until one of three things happen:

        • The count reaches zero due to invocations of the countDown() method on any node; or
        • Some other thread interrupts the current thread; or
        • The specified waiting time elapses.

        If the count reaches zero then the method returns with the value true.

        If the current thread:

        • has its interrupted status set on entry to this method; or
        • is interrupted while waiting,
        then IgniteInterruptedCheckedException is thrown and the current thread's interrupted status is cleared.

        If the specified waiting time elapses then the value false is returned. If the time is less than or equal to zero, the method will not wait at all.

        Parameters:
        timeout - The maximum time to wait in milliseconds.
        Returns:
        True if the count reached zero and false if the waiting time elapsed before the count reached zero.
        Throws:
        IgniteInterruptedException - If the current thread is interrupted while waiting.
        IgniteException - If operation failed.

      • await

        boolean await​(long timeout,
              TimeUnit unit)
       throws IgniteException
        Causes the current thread to wait until the latch has counted down to zero, unless the thread is interrupted, or the specified waiting time elapses.

        If the current count is zero then this method returns immediately with the value true.

        If the current count is greater than zero then the current thread becomes disabled for thread scheduling purposes and lies dormant until one of three things happen:

        • The count reaches zero due to invocations of the countDown() method on any node; or
        • Some other thread interrupts the current thread; or
        • The specified waiting time elapses.

        If the count reaches zero then the method returns with the value true.

        If the current thread:

        • has its interrupted status set on entry to this method; or
        • is interrupted while waiting,
        then IgniteInterruptedCheckedException is thrown and the current thread's interrupted status is cleared.

        If the specified waiting time elapses then the value false is returned. If the time is less than or equal to zero, the method will not wait at all.

        Parameters:
        timeout - The maximum time to wait.
        unit - The time unit of the timeout argument.
        Returns:
        True if the count reached zero and false if the waiting time elapsed before the count reached zero.
        Throws:
        IgniteInterruptedException - If the current thread is interrupted while waiting.
        IgniteException - If operation failed.

      • countDown

        int countDown()
       throws IgniteException
        Decrements the count of the latch, releasing all waiting threads on all nodes if the count reaches zero.

        If the current count is greater than zero then it is decremented. If the new count is zero then all waiting threads are re-enabled for thread scheduling purposes.

        If the current count equals zero then nothing happens.

        Returns:
        Count after decrement.
        Throws:
        IgniteException - If operation failed.

      • countDown

        int countDown​(int val)
       throws IgniteException
        Decreases the count of the latch using passed in value, releasing all waiting threads on all nodes if the count reaches zero.

        If the current count is greater than zero then it is decreased. If the new count is zero then all waiting threads are re-enabled for thread scheduling purposes.

        If the current count equals zero then nothing happens.

        Parameters:
        val - Value to decrease counter on.
        Returns:
        Count after decreasing.
        Throws:
        IgniteException - If operation failed.

      • countDownAll

        void countDownAll()
           throws IgniteException
        Counts down this latch to zero, releasing all waiting threads on all nodes.

        If the current count equals zero then nothing happens.

        Throws:
        IgniteException - If operation failed.

      • removed

        boolean removed()
        Gets removed status of the latch.
        Returns:
        True if latch was removed from cache, false otherwise.