Java application consumes more CPU cycles -


we noticed our application consumes 99% cpu cycle in linux , identified thread running in indefinite loop, causes issue. noticed strange behavior on this. based on parameters, thread schedule timer task. if timer task scheduled cpu usage went down 20%. if it's not scheduled cpu usage 100%. curious know how introducing processing thread brings down cpu usage 10-20%.

public void run()      {         log.info("starting vcmg channel thread...");         while (true) {              if (readpacket()) {                  loyaltymessagehandle mh = null;                  synchronized(this)                  {                     if(map.containskey(respstan))                      {                          mh = (loyaltymessagehandle) map.get(respstan);                         mh.setloyaltyresp(loyaltyobject);                         resetheartbeattimer();                     }                      else                     {                         //just drop packet on floor... timedout.                         if (!log.isdebugenabled())                          {                             log.warn("packet: [" + new string(loyaltyobject).substring(0,28) +                                  "...] dropped !!!!!");                         }                         else                          {                             log.debug("packet: [" + new string(loyaltyobject) + "] dropped !!!!!");                         }                     }                 }                  if(mh != null) {                     synchronized(mh) {                         mh.notify();                     }                 }             }          }      }   public synchronized void resetheartbeattimer()     {         if (heartbeattimer != null)          {             heartbeattimer.cancel();         }         startheartbeat();     }   public synchronized void startheartbeat()      {         heartbeattimeout = loyaltymgr.getheartbeatinactivetimer() * 1000;          // timeout value 0 indicates 'heartbeat' needs disabled.         // if timeout value less 0 should ignored since cause exception.         if ((heartbeattimeout > 0) && (this.clientsocket.isconnected()))          {             if (heartbeattimeout < heart_beat_lowest_timeout)              {                 heartbeattimeout = heart_beat_lowest_timeout;             }             heartbeattimer = new heartbeattimer(this, loyaltymgr.getheartbeattimeout());             timer timer = new timer();             timer.schedule(heartbeattimer, heartbeattimeout);         }     }

because if loop running tight no "sleep" using cpu

if put sleep in or otherwise make contention possible thread cpu isn't being used

your timer must sleeping loop , using less cpu time


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