Check if notifier thread is running before warning

cpp/include/ucxx/notifier.h

@@ -97,6 +97,13 @@ class Notifier {
    * it should stop and exit.
    */
   virtual void stopRequestNotifierThread() = 0;
+
+  /**
+   * @brief Returns whether the thread is running.
+   *
+   * @returns Whether the thread is running.
+   */
+  [[nodiscard]] virtual bool isRunning() const = 0;
 };
 
 }  // namespace ucxx

cpp/include/ucxx/worker_progress_thread.h

@@ -162,6 +162,11 @@ class WorkerProgressThread {
    */
   [[nodiscard]] std::thread::id getId() const;
 
+  /**
+   * @brief Returns whether the thread is running.
+   *
+   * @returns Whether the thread is running.
+   */
   [[nodiscard]] bool isRunning() const;
 
   void stop();

cpp/python/include/ucxx/python/notifier.h

@@ -139,6 +139,13 @@ class Notifier : public ::ucxx::Notifier {
    * that it should stop and exit.
    */
   void stopRequestNotifierThread() override;
+
+  /**
+   * @brief Returns whether the thread is running.
+   *
+   * @returns Whether the thread is running.
+   */
+  [[nodiscard]] bool isRunning() const override;
 };
 
 }  // namespace python

cpp/python/src/notifier.cpp

@@ -122,6 +122,12 @@ void Notifier::stopRequestNotifierThread()
   _notifierThreadConditionVariable.notify_all();
 }
 
+bool Notifier::isRunning() const
+{
+  return _notifierThreadFutureStatusReady ||
+         _notifierThreadFutureStatusFinished == RequestNotifierThreadState::Running;
+}
+
 }  // namespace python
 
 }  // namespace ucxx

cpp/src/worker.cpp

@@ -170,7 +170,7 @@ Worker::~Worker()
       "unintended effects, such as destructor being called from that thread.");
     stopProgressThreadNoWarn();
   }
-  if (_notifier) {
+  if (_notifier && _notifier->isRunning()) {
     ucxx_warn(
       "The notifier thread should be explicitly stopped with `stopNotifierThread()` to prevent "
       "unintended effects, such as destructor being called from that thread.");