code: private void submit(final ActiveContext context) {
      try {
        LOG.log(Level.INFO, "Send task to context: {0}", new Object[]{context});
        if (JobDriver.this.handlerManager.getActiveContextHandler() == 0) {
          throw new RuntimeException("Active Context Handler not initialized by CLR.");
        }
        final ActiveContextBridge activeContextBridge = activeContextBridgeFactory.getActiveContextBridge(context);
        NativeInterop.clrSystemActiveContextHandlerOnNext(JobDriver.this.handlerManager.getActiveContextHandler(),
            activeContextBridge, JobDriver.this.interopLogger);
      } catch (final Exception ex) {
        LOG.log(Level.SEVERE, "Fail to submit task to active context");
        context.close();
        throw new RuntimeException(ex);
      }
    }
docs: Submit a Task to a single Evaluator.