@Override
    public void rejectedExecution(Runnable r, ThreadPoolExecutor executor) {
      if (executor.isShutdown()) {
        throw new RejectedExecutionException("executor has been shutdown");
      }
      if (isBufferConsumer((FunctionExecutionPooledExecutor) executor)) {
        handleRejectedExecutionForBufferConsumer(r, executor);
      } else if (isFunctionExecutionThread()) {
        handleRejectedExecutionForFunctionExecutionThread(r, executor);
      } else {
        // In the normal case, add the rejected request to the blocking queue.
        try {
          blockingQueue.put(r);
        } catch (InterruptedException e) {
          Thread.currentThread().interrupt();
          // this thread is being shutdown so just return;
        }
      }
    }
Is the current thread used for executing Functions?
geode-core/src/main/java/org/apache/geode/distributed/internal/FunctionExecutionPooledExecutor.java