fix(metrics, logs): Kill telemetry buffer threads on close

sentry-ruby/lib/sentry-ruby.rb

@@ -301,6 +301,8 @@ def close
       if client = get_current_client
         client.configuration.run_after_close_callbacks
         client.flush
+        client.log_event_buffer.kill
+        client.metric_event_buffer.kill
 
         if client.configuration.data_collection.collect_stack_frame_variables?
           exception_locals_tp.disable

sentry-ruby/lib/sentry/client.rb

@@ -130,8 +130,8 @@ def capture_envelope(envelope)
     def flush
       transport.flush if configuration.sending_to_dsn_allowed?
       spotlight_transport.flush if spotlight_transport
-      @log_event_buffer&.flush
-      @metric_event_buffer&.flush
+      @log_event_buffer.flush
+      @metric_event_buffer.flush
     end
 
     # Initializes an Event object with the given exception. Returns `nil` if the exception's class is excluded from reporting.

sentry-ruby/spec/sentry_spec.rb

@@ -1594,6 +1594,21 @@
         described_class.close
       end
 
+      it "kills telemetry workers" do
+        client = described_class.get_current_client
+        client.log_event_buffer.add_item(Sentry::LogEvent.new(level: :info, body: "log"))
+        client.metric_event_buffer.add_item(Sentry::MetricEvent.new(name: "metric", type: :counter, value: 1))
+        log_thread = client.log_event_buffer.thread
+        metric_thread = client.metric_event_buffer.thread
+
+        described_class.close
+
+        expect(log_thread.join(1)).to eq(log_thread)
+        expect(metric_thread.join(1)).to eq(metric_thread)
+        expect(log_thread).not_to be_alive
+        expect(metric_thread).not_to be_alive
+      end
+
       it "flushes session flusher" do
         expect(described_class.session_flusher).to receive(:flush)
         described_class.close