Interface CountDownLatch

    • Method Summary

      All Methods Instance Methods Abstract Methods 
      Modifier and Type Method Description
      void await()
      Causes the current thread to wait until the latch has counted down to zero, unless the thread is interrupted.
      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 countDown()
      Decrements the count of the latch, releasing all waiting threads if the count reaches zero.
      long getCount()
      Returns the current count.
    • Method Detail

      • await

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

        If the current count 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; 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 InterruptedException is thrown and the current thread's interrupted status is cleared.
        Throws:
        InterruptedException - if the current thread is interrupted while waiting
      • await

        boolean await​(long timeout,
                      TimeUnit unit)
               throws InterruptedException
        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; 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 InterruptedException 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 if the waiting time elapsed before the count reached zero
        Throws:
        InterruptedException - if the current thread is interrupted while waiting
      • countDown

        void countDown()
        Decrements the count of the latch, releasing all waiting threads 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.

      • getCount

        long getCount()
        Returns the current count.

        This method is typically used for debugging and testing purposes.

        Returns:
        the current count