Package org.apache.curator.framework.recipes.barriers

Class DistributedDoubleBarrier

  • public class DistributedDoubleBarrier
extends java.lang.Object

    A double barrier as described in the ZK recipes. Quoting the recipe:

    Double barriers enable clients to synchronize the beginning and the end of a computation. When enough processes have joined the barrier, processes start their computation and leave the barrier once they have finished.

    • Constructor Summary

      Constructors 
      Constructor Description
      DistributedDoubleBarrier​(org.apache.curator.framework.CuratorFramework client, java.lang.String barrierPath, int memberQty)
      Creates the barrier abstraction.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void enter()
      Enter the barrier and block until all members have entered
      boolean enter​(long maxWait, java.util.concurrent.TimeUnit unit)
      Enter the barrier and block until all members have entered or the timeout has elapsed
      protected java.util.List<java.lang.String> getChildrenForEntering()  
      void leave()
      Leave the barrier and block until all members have left
      boolean leave​(long maxWait, java.util.concurrent.TimeUnit unit)
      Leave the barrier and block until all members have left or the timeout has elapsed

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Constructor Detail

      • DistributedDoubleBarrier

        public DistributedDoubleBarrier​(org.apache.curator.framework.CuratorFramework client,
                                java.lang.String barrierPath,
                                int memberQty)
        Creates the barrier abstraction. memberQty is the number of members in the barrier. When enter() is called, it blocks until all members have entered. When leave() is called, it blocks until all members have left.
        Parameters:
        client - the client
        barrierPath - path to use
        memberQty - the number of members in the barrier. NOTE: more than memberQty can enter the barrier. memberQty is a threshold, not a limit

    • Method Detail

      • enter

        public void enter()
           throws java.lang.Exception
        Enter the barrier and block until all members have entered
        Throws:
        java.lang.Exception - interruptions, errors, etc.

      • enter

        public boolean enter​(long maxWait,
                     java.util.concurrent.TimeUnit unit)
              throws java.lang.Exception
        Enter the barrier and block until all members have entered or the timeout has elapsed
        Parameters:
        maxWait - max time to block
        unit - time unit
        Returns:
        true if the entry was successful, false if the timeout elapsed first
        Throws:
        java.lang.Exception - interruptions, errors, etc.

      • leave

        public void leave()
           throws java.lang.Exception
        Leave the barrier and block until all members have left
        Throws:
        java.lang.Exception - interruptions, errors, etc.

      • leave

        public boolean leave​(long maxWait,
                     java.util.concurrent.TimeUnit unit)
              throws java.lang.Exception
        Leave the barrier and block until all members have left or the timeout has elapsed
        Parameters:
        maxWait - max time to block
        unit - time unit
        Returns:
        true if leaving was successful, false if the timeout elapsed first
        Throws:
        java.lang.Exception - interruptions, errors, etc.

      • getChildrenForEntering

        protected java.util.List<java.lang.String> getChildrenForEntering()
                                                           throws java.lang.Exception
        Throws:
        java.lang.Exception