Merge pull request #139 from kbase/dev-service

Handle uncaught exceptions in coroutine manager and simplify

cdmtaskservice/app_state.py

@@ -58,7 +58,7 @@ async def build_app(
     # This method is getting pretty long but it's stupid simple so...
     # May want to parallelize some of this for faster startups. would need to rework prints
     logr = logging.getLogger(__name__)
-    coman = await CoroutineWrangler.create()
+    coman = CoroutineWrangler()
     logr.info("Connecting to KBase auth service... ")
     auth = await KBaseAuth.create(
         cfg.auth_url,
@@ -112,6 +112,7 @@ async def build_app(
         images = Images(mongodao, imginfo)
         job_submit = JobSubmit(mongodao, s3, coman, runners)
         app.state._mongo = mongocli
+        app.state._coroman = coman
         app.state._cdmstate = AppState(
             auth, sfapi_client, s3, job_submit, job_state, images, runners
         )
@@ -133,6 +134,7 @@ async def destroy_app_state(app: FastAPI):
     """
     appstate = _get_app_state_from_app(app)  # first to check state was set up
     app.state._mongo.close()
+    app.state._coroman.destroy()
     await appstate.sfapi_client.destroy()
     # https://docs.aiohttp.org/en/stable/client_advanced.html#graceful-shutdown
     await asyncio.sleep(0.250)

cdmtaskservice/coroutine_manager.py

@@ -8,49 +8,41 @@
 
 import asyncio
 import logging
-from typing import Awaitable, Self
+from typing import Awaitable
 
 from cdmtaskservice.arg_checkers import not_falsy as _not_falsy
 
 
-_CLOSE_DELAY_SEC = 60
-
-
 class CoroutineWrangler:
     """ The coroutine manager. """
 
-    @classmethod
-    async def create(cls) -> Self:
-        """ Create the coroutine manager. """
-        cw = CoroutineWrangler()
-        cw._reaper_task = asyncio.create_task(cw._reaper())
-        return cw
-
     def __init__(self):
-        self._closedelay = _CLOSE_DELAY_SEC  # may want to make configurable?
-        self._coros = []
+        """ Create the coroutine manager. """
+        self._coros = set()
         self._destroy = False
 
-    # TODO CODE There's a simpler say to deal with this. Write tests and then implement
-    #      https://docs.python.org/3/library/asyncio-task.html#asyncio.create_task
-    async def _reaper(self):
-        logr = logging.getLogger(__name__)
-        while not self._destroy:
-            await asyncio.sleep(self._closedelay)
-            logr.info(f"Reaper processing {len(self._coros)} coroutines")
-            self._coros = [coro for coro in self._coros if not coro.done()]
-            logr.info(f"Reaper: {len(self._coros)} coroutines remaining")
-
     async def run_coroutine(self, coro: Awaitable):
         """ Run a coroutine to completion. """
         if self._destroy:
             raise ValueError("Manager is destroyed")
-        task = asyncio.create_task(_not_falsy(coro, "coro"))
-        self._coros.append(task)
-
-    async def destroy(self):
+        task = asyncio.create_task(self._exception_wrapper(_not_falsy(coro, "coro")))
+        self._coros.add(task)
+        task.add_done_callback(self._coros.discard)
+        logging.getLogger(__name__).info(
+            f"Running coroutine {coro}. {len(self._coros)} coroutines running."
+        )
+
+    async def _exception_wrapper(self, coro):
+        try:
+            await coro
+        except Exception as e:
+            logging.getLogger(__name__).exception(
+                f"Coroutine {coro} threw an unhandled exception: {e}"
+            )
+            # Nothing else can be done
+
+    def destroy(self):
         """ Cancel all coroutines and destroy the manager. """
         self._destroy = True
-        self._reaper_task.cancel()
         for coro in self._coros:
             coro.cancel()