code: protected void wakeupReadAhead() {
          if (TraceComponent.isAnyTracingEnabled() && tc.isDebugEnabled()) {
              Tr.debug(tc, "Received synchronous read-ahead wake-up call.");
          }
          synchronized (this.readAheadSyncer) {
              this.readAheadSyncer.notify();
          }
      }
docs: Method used by the read-ahead callback thread to notify this service
  context that the read has completed.