private void tryReactivate(WorkQueue w,WorkQueue[] ws,int r){
  long c;
  int sp, wl;
  WorkQueue v;
  if ((sp=(int)(c=ctl)) != 0 && w != null && ws != null && (wl=ws.length) > 0 && ((sp ^ r) & SS_SEQ) == 0 && (v=ws[(wl - 1) & sp]) != null) {
    long nc=(v.stackPred & SP_MASK) | (UC_MASK & (c + AC_UNIT));
    int ns=sp & ~UNSIGNALLED;
    if (w.scanState < 0 && v.scanState == sp && U.compareAndSwapLong(this,CTL,c,nc)) {
      v.scanState=ns;
      LockSupport.unpark(v.parker);
    }
  }
}

private void tryReactivate ( WorkQueue w , WorkQueue [ ] ws , int r ) { long c ; int sp , wl ; WorkQueue v ; if ( ( sp = ( int ) ( c = ctl ) ) != 0 && w != null && ws != null && ( wl = ws . length ) > 0 && ( ( sp ^ r ) & SS_SEQ ) == 0 && ( v = ws [ ( wl - 1 ) & sp ] ) != null ) { long nc = ( v . stackPred & SP_MASK ) | ( UC_MASK & ( c + AC_UNIT ) ) ; int ns = sp & ~ UNSIGNALLED ; if ( w . scanState < 0 && v . scanState == sp && U . compareAndSwapLong ( this , CTL , c , nc ) ) { v . scanState = ns ; LockSupport . unpark ( v . parker ) ; } } }
with approx probability of a missed signal , tries ( once ) to reactivate worker w ( or some other worker ) , failing if stale or known to be already active .
