.net - How can a thread use less than 100% wall time? -

when profiling application (using dottrace), noticed strange thing. used "wall time" measurement, should in theory mean threads run same amount of time.

but wasn't true: threads (actually interested in) displayed total time 2 times less others. example, profiling ran 230 seconds, most threads report 230 seconds spent in thread, 5 threads show 100-110 seconds. these not threadpool threads, , created , started before profiling started.

what going on here?

update i'll add more info may or may not relevant. application in question (it game server) has 20-30 running threads. threads follow simple pattern: check incoming queue work, , work if there some. code thread func looks this:

while(true){     if(trydequeuework()){ // if queue not empty         dowork();         // whatever on top     }else{         m_waithandle.waitone(maxtimeout); // m_waithandle gets signaled when work added queue     } } 

the threads display weird times this, except serve multiple queues, this:

while(true){     bool hasanywork=false;     foreach(var queue in m_queues){         if(queue.trydequeuework()){             hasanywork=true;             dowork();         }     }     if(!hasanywork){          m_waithandle.waitone(maxtimeout);      } } 

the weird threads don't io except maybe logging. other, non-weird threads, logging too. time spent waiting waithandle reported in profiler; actually, of non-weird threads spend of time waiting (as never have work).

the application running on 8-core virtual machine (vps hosting). don't know physical processors used there.

did finish before profiler finished, perhaps?