multithreading - Java : One thread needs to wait for other to be done -

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i have following use case. can suggest implementation of method t1() assuming run on java 6 ? tried think of accomplishing using wait() , notify() not proper solution. appreciated. (note both of these methods t1() , m1() called in different threads)

 class test  {     static volatile int flag = 0;     public static void t1()    {            //this method called in thread called t2            /*this method must wait flag become 1.              becomes 1 must return. should wait maximum               n seconds. after if flag 0 must return.*/    }       public static void m1()    {            //this method called in thread called t1            flag = 1;    } }

this tried far implementation of t1()

   public static void t1() throws interruptedexception    {           while(flag == 0)           {                thread.currentthread().sleep(100);           }    }

above works problem timeout not implemented , while loop not seem good.

use countdownlatch. initialize before of threads run count one. code this:

class test  {     static countdownlatch latch = new countdownlatch(1);     public static void t1()    {            //this method called in thread called t2            /*this method must wait flag become 1.              becomes 1 must return. should wait maximum               n seconds. after if flag 0 must return.*/            latch.await(1l,timeunit.seconds);            //your remaining logic    }       public static void m1()    {           //your logic           latch.countdown();    } }

a countdownlatch modified, enhanced (e.g. timeout option), , arguably easier-to-understand implementation of semaphore - 1 of basic structures used thread synchronization across number of languages (not java). note following when comparing wikipedia reference java implementation:

  • p/wait() corresponds await(), difference await() doesn't change count value.
  • v/signal() corresponds countdown(), difference countdown() counts down, not (obviously).

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