java - Threads Execution -

is possible know when thread has completed execution without using of builtin function isalive, join. suppose have 3 threads a, b , c running in parallel. how know whether threads have completed execution.

you can use countdownlatch out it. let's you're making threads executorservice, make like

        countdownlatch latch = new countdownlatch(threadscount);         executorservice executor = executors.newfixedthreadpool(threadscount);          (int x = 0; x < threadscount; x++)         {             executor.submit(new classname(latch));         }         try         {             latch.await();         }         catch (exception ignored){}  //all threads done @ point 

and in classname should have this:

class classname implements runnable {     private countdownlatch latch;      //constructor:     classname(countdownlatch latch)     {          this.latch = latch;     }      //run method:     @override     void run()     {         //your thread code...          latch.countdown();     } } 

so in run-method in classname, need call latch.countdown().

countdownlatch automatically syncronized, don't need think that.

you don't need use exectuorservice in order use latch, example.