tests: use try/finally to close event loop + wait for process to die after killing it

artiq/master/worker.py

@@ -101,6 +101,8 @@ class Worker:
                 logger.warning("failed to send terminate command to worker"
                                " (RID %d), killing", self.rid, exc_info=True)
                 self.process.kill()
+                # Wait for process to terminate
+                yield from self.process.communicate()
                 return
             try:
                 yield from asyncio_process_wait_timeout(self.process,
@@ -108,6 +110,8 @@ class Worker:
             except asyncio.TimeoutError:
                 logger.warning("worker did not exit (RID %d), killing", self.rid)
                 self.process.kill()
+                # Wait for process to terminate
+                yield from self.process.communicate()
             else:
                 logger.debug("worker exited gracefully (RID %d)", self.rid)
         finally:

artiq/test/pc_rpc.py

@@ -75,7 +75,9 @@ class RPCCase(unittest.TestCase):
     def _loop_asyncio_echo(self):
         loop = asyncio.new_event_loop()
         asyncio.set_event_loop(loop)
+        try:
             loop.run_until_complete(self._asyncio_echo())
+        finally:
             loop.close()
 
     def test_asyncio_echo(self):

artiq/test/worker.py

@@ -40,8 +40,7 @@ def _call_worker(worker, expid):
 
 
 def _run_experiment(experiment):
-    loop = asyncio.new_event_loop()
-    asyncio.set_event_loop(loop)
+    try:
         expid = {
             "file": sys.modules[__name__].__file__,
             "experiment": experiment,
@@ -51,12 +50,19 @@ def _run_experiment(experiment):
             "init_rt_results": lambda description: None
         }
 
+        loop = asyncio.get_event_loop()
         worker = Worker(handlers)
         loop.run_until_complete(_call_worker(worker, expid))
+    finally:
         loop.close()
 
 
 class WatchdogCase(unittest.TestCase):
+
+    def setUp(self):
+        self.loop = asyncio.new_event_loop()
+        asyncio.set_event_loop(self.loop)
+
     def test_watchdog_no_timeout(self):
         _run_experiment("WatchdogNoTimeout")
 
@@ -67,3 +73,6 @@ class WatchdogCase(unittest.TestCase):
     def test_watchdog_timeout_in_build(self):
         with self.assertRaises(WorkerWatchdogTimeout):
             _run_experiment("WatchdogTimeoutInBuild")
+
+    def tearDown(self):
+        self.loop.close()