code: public static void shutdown() {
          if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled()) {
              Tr.entry(tc, "shutdown");
          }
          synchronized (oneAtATime) {
              if (TraceComponent.isAnyTracingEnabled() && tc.isDebugEnabled()) {
                  Tr.debug(tc, "have lock"); // running with fixes (2)");
              }
  
              if (aioInitialized == AIO_INITIALIZED) {
                  // mark the library as shutdown
                  aioInitialized = AIO_SHUTDOWN;
                  // Shut down sequence for the library...
                  closeAllCompletionPorts();
                  try {
                      aio_shutdown();
                  } catch (AsyncException ae) {
                      // ignore shutdown errors
                      if (TraceComponent.isAnyTracingEnabled() && tc.isDebugEnabled()) {
                          Tr.debug(tc, "AsyncException occured while shutting down: " + ae.getMessage());
                      }
                  }
              }
          } // end-sync
          if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled()) {
              Tr.exit(tc, "shutdown");
          }
      }
docs: Shutdown the AIO library.