don't use __del__ and implement Tracer.shutdown

opentelemetry-sdk/src/opentelemetry/sdk/trace/__init__.py

@@ -321,26 +321,24 @@ class Tracer(trace_api.Tracer):
 
     Args:
         name: The name of the tracer.
+        shutdown_on_exit: Register an atexit hook to shutdown the tracer when
+        the application exits.
     """
 
     def __init__(
         self,
         name: str = "",
         sampler: sampling.Sampler = trace_api.sampling.ALWAYS_ON,
+        shutdown_on_exit: bool = True,
     ) -> None:
         slot_name = "current_span"
         if name:
             slot_name = "{}.current_span".format(name)
         self._current_span_slot = Context.register_slot(slot_name)
         self._active_span_processor = MultiSpanProcessor()
         self.sampler = sampler
-        self._atexit_hanlder = atexit.register(
-            self._active_span_processor.shutdown
-        )
-
-    def __del__(self):
-        atexit.unregister(self._atexit_hanlder)
-        self._active_span_processor.shutdown()
+        if shutdown_on_exit:
+            self._atexit_handler = atexit.register(self.shutdown)
 
     def get_current_span(self):
         """See `opentelemetry.trace.Tracer.get_current_span`."""
@@ -462,5 +460,11 @@ def add_span_processor(self, span_processor: SpanProcessor) -> None:
         # thread safe
         self._active_span_processor.add_span_processor(span_processor)
 
+    def shutdown(self):
+        """Shutdown the span processors added to the tracer."""
+        self._active_span_processor.shutdown()
+        if hasattr(self, "_atexit_handler"):
+            atexit.unregister(self._atexit_handler)
+
 
 tracer = Tracer()