Fix "RuntimeError: cannot schedule new futures after interpreter shutdown"

docs/versionhistory.rst

@@ -8,6 +8,8 @@ APScheduler, see the :doc:`migration section <migration>`.
 
 - Fixed ``scheduler.shutdown()`` not raising ``SchedulerNotRunning`` (or raising the
   wrong exception) for asynchronous schedulers when the scheduler is in fact not running
+- Fixed "RuntimeError: cannot schedule new futures after interpreter shutdown" (#985
+<https://github.com/agronholm/apscheduler/issues/985>_; PR by @i-am-darshil)
 
 **3.11.0**
 

src/apscheduler/executors/pool.py

@@ -5,6 +5,11 @@
 
 from apscheduler.executors.base import BaseExecutor, run_job
 
+SHUTDOWN_MESSAGES = {
+    "cannot schedule new futures after shutdown",
+    "cannot schedule new futures after interpreter shutdown",
+}
+
 
 class BasePoolExecutor(BaseExecutor):
     @abstractmethod
@@ -24,9 +29,20 @@ def callback(f):
             else:
                 self._run_job_success(job.id, f.result())
 
-        f = self._pool.submit(
-            run_job, job, job._jobstore_alias, run_times, self._logger.name
-        )
+        try:
+            f = self._pool.submit(
+                run_job, job, job._jobstore_alias, run_times, self._logger.name
+            )
+        except RuntimeError as e:
+            # There is a possible race condition between shutdown being invoked and the job being submitted to pool.
+            # This helps with not polluting logs with RuntimeError traces.
+            if str(e) in SHUTDOWN_MESSAGES:
+                self._logger.warning(
+                    "Executor has been shut down, skipping job %s: %s", job.id, e
+                )
+                return
+            else:
+                raise  # Re-raise unexpected RuntimeErrors
         f.add_done_callback(callback)
 
     def shutdown(self, wait=True):

tests/test_executors.py

@@ -1,4 +1,5 @@
 import gc
+import logging
 import os
 import signal
 import time
@@ -273,6 +274,32 @@ async def test_run_coroutine_job(asyncio_scheduler, asyncio_executor, exception)
         assert events[0].retval is True
 
 
+@pytest.mark.parametrize(
+    "message,raise_error",
+    [
+        ("cannot schedule new futures after shutdown", False),
+        ("cannot schedule new futures after interpreter shutdown", False),
+        ("random RuntimeError", True),
+    ],
+)
+def test_pool_shutdown(
+    mock_scheduler, executor, create_job, timezone, caplog, message, raise_error
+):
+    executor._pool.submit = MagicMock(side_effect=RuntimeError(message))
+    with caplog.at_level(logging.WARNING):
+        try:
+            job = create_job(func=wait_event, max_instances=2, next_run_time=None)
+            run_time = datetime.now(timezone)
+            executor.submit_job(job, [run_time])
+            if raise_error:
+                pytest.fail("Random RuntimeErrors should be raised!")
+        except RuntimeError:
+            if not raise_error:
+                pytest.fail(
+                    "Shutdown RuntimeErrors should be caught and logged, not raised!"
+                )
+
+
 @pytest.mark.parametrize("exception", [False, True])
 @pytest.mark.anyio
 async def test_run_coroutine_job_tornado(