fix missing sleep to properly poll inside activity (#122)

* fix missing sleep to properly poll inside activity

* implement Chads guidance

* take2 and wrap whole thing in cancellederror

* moar better log

* await the things

* make test_service be async

* poe!

polling/frequent/activities.py

@@ -1,3 +1,5 @@
+import asyncio
+import time
 from dataclasses import dataclass
 
 from temporalio import activity
@@ -16,7 +18,18 @@ async def compose_greeting(input: ComposeGreetingInput) -> str:
     test_service = TestService()
     while True:
         try:
-            result = test_service.get_service_result(input)
-            return result
-        except Exception:
+            try:
+                result = await test_service.get_service_result(input)
+                activity.logger.info(f"Exiting activity ${result}")
+                return result
+            except Exception as e:
+                # swallow exception since service is down
+                activity.logger.debug("Failed, trying again shortly", exc_info=True)
+
             activity.heartbeat("Invoking activity")
+            await asyncio.sleep(1)
+        except asyncio.CancelledError:
+            # activity was either cancelled or workflow was completed or worker shut down
+            # if you need to clean up you can catch this.
+            # Here we are just reraising the exception
+            raise

polling/test_service.py

@@ -3,7 +3,7 @@ def __init__(self):
         self.try_attempts = 0
         self.error_attempts = 5
 
-    def get_service_result(self, input):
+    async def get_service_result(self, input):
         print(
             f"Attempt {self.try_attempts}"
             f" of {self.error_attempts} to invoke service"