java - Should I synchronize method in my example? -

i'm not sure if should synchronize method methodone() in example. think not i'm not 100% sure. please give me advice do?

public class synchroissue {  class test {     private double = 0;      void methodone() {          a++;     }      void go() {         new thread(new runnable() {              @override             public void run() {                 (int = 0; < integer.max_value; i++) {                     methodone();                     system.out.println(thread.currentthread().getname() + ", = " + a);                 }             }         }).start();     } }  public static void main(string... args) {     synchroissue mainobj = new synchroissue();      synchroissue.test object1 = mainobj.new test();     synchroissue.test object2 = mainobj.new test();      object1.go();     object2.go(); } } 

assuming going use instances of synchroissue class concurrently, not doing currently, answer yes.

the increment operator not atomic. 3 instructions:

1. get current value.

2. add 1 that.

3. store new value.

if not synchronized, concurrent threads can overlap steps resulting in strange behavior.

another option, if interested in integers, use of atomicinteger, has methods atomically increment.