concurrency - Is this a good design for implementing the java synchronized keyword as an object? -

just practice wanted implement java synchronized keyword java object. code below design this? guess atomicreference have similar performance atomicboolean?

updated code after suggestions:

public class synchronizedblock implements runnable{  private final lock lock; private final runnable runnable;  public synchronizedblock(runnable r, lock l){     runnable = r;     lock = l; }  public void run() {     try {         while(!lock.compareandset(false, true)){             thread.sleep(100);         }         runnable.run();     } catch (interruptedexception e) {         e.printstacktrace();     } {         lock.unlock();     }   }   }   public class lock { private final atomicreference<boolean> locked = new atomicreference<boolean>(false);  public boolean compareandset(boolean expected, boolean update){     return locked.compareandset(expected, update); }  public boolean islocked(){     return locked.get(); }  public void unlock(){     locked.set(false); }  }  @test public void test() {        final synchronizedblock sb = new synchronizedblock(new runnable(){          public void run() {             x++;             system.out.println(x);         }      }, new lock());      runnable r1 = new runnable(){          int c = 0;         public void run() {             while(c<10){                 sb.run();                 c++;             }         }      };      runnable r2 = new runnable(){          int c = 0;         public void run() {             while(c<10){                 sb.run();                 c++;             }         }      };      thread t1 = new thread(r1);     thread t2 = new thread(r2);      t1.start();     t2.start();      while (t1.isalive() && t2.isalive()){      }      assertequals(20,x);  } 

you should add method encapsulate compareandswap, , there no point looping lock free before attempting obtain it. why in situation can see lock free time try take it, gone.

i remove lock method , place unlock in lock exception/error doesn't result in lock never unlocks.

also use atomicboolean more natural atomicreference