private long tryIncReaderOverflow(long s){
  if ((s & ABITS) == RFULL) {
    if (U.compareAndSwapLong(this,STATE,s,s | RBITS)) {
      ++readerOverflow;
      state=s;
      return s;
    }
  }
 else   if ((LockSupport.nextSecondarySeed() & OVERFLOW_YIELD_RATE) == 0)   Thread.yield();
  return 0L;
}

private long tryIncReaderOverflow ( long s ) { if ( ( s & ABITS ) == RFULL ) { if ( U . compareAndSwapLong ( this , STATE , s , s | RBITS ) ) { ++ readerOverflow ; state = s ; return s ; } } else if ( ( LockSupport . nextSecondarySeed ( ) & OVERFLOW_YIELD_RATE ) == 0 ) Thread . yield ( ) ; return 0L ; }
tries to increment readeroverflow by first setting state access bits value to rbits , indicating hold of spinlock , then updating , then releasing .
