From 16204c706d15dfc2b5949d8c467427ad6d576299 Mon Sep 17 00:00:00 2001
From: Samuel Merritt <sam@swiftstack.com>
Date: Tue, 17 Dec 2013 16:11:26 -0800
Subject: [PATCH] Preserve tracebacks from run_in_thread
Now the traceback goes all the way down to where the exception came
from, not just down to run_in_thread. Better for debugging.
Change-Id: Iac6acb843a6ecf51ea2672a563d80fa43d731f23
---
swift/common/utils.py | 6 ++--
test/unit/common/test_utils.py | 53 ++++++++++++++++++++++------------
2 files changed, 37 insertions(+), 22 deletions(-)
diff --git a/swift/common/utils.py b/swift/common/utils.py
index 78f69781a6..f19fd7a48d 100644
--- a/swift/common/utils.py
+++ b/swift/common/utils.py
@@ -2233,8 +2233,8 @@ class ThreadPool(object):
try:
result = func(*args, **kwargs)
result_queue.put((ev, True, result))
- except BaseException as err:
- result_queue.put((ev, False, err))
+ except BaseException:
+ result_queue.put((ev, False, sys.exc_info()))
finally:
work_queue.task_done()
os.write(self.wpipe, self.BYTE)
@@ -2264,7 +2264,7 @@ class ThreadPool(object):
if success:
ev.send(result)
else:
- ev.send_exception(result)
+ ev.send_exception(*result)
finally:
queue.task_done()
diff --git a/test/unit/common/test_utils.py b/test/unit/common/test_utils.py
index e7eb0b99a4..4a362b2295 100644
--- a/test/unit/common/test_utils.py
+++ b/test/unit/common/test_utils.py
@@ -33,6 +33,7 @@ from textwrap import dedent
import tempfile
import threading
import time
+import traceback
import unittest
import fcntl
import shutil
@@ -2578,13 +2579,8 @@ class TestThreadpool(unittest.TestCase):
result = tp.force_run_in_thread(self._capture_args, 1, 2, bert='ernie')
self.assertEquals(result, {'args': (1, 2),
'kwargs': {'bert': 'ernie'}})
-
- caught = False
- try:
- tp.force_run_in_thread(self._raise_valueerror)
- except ValueError:
- caught = True
- self.assertTrue(caught)
+ self.assertRaises(ValueError, tp.force_run_in_thread,
+ self._raise_valueerror)
def test_run_in_thread_without_threads(self):
# with zero threads, run_in_thread doesn't actually do so
@@ -2597,13 +2593,8 @@ class TestThreadpool(unittest.TestCase):
result = tp.run_in_thread(self._capture_args, 1, 2, bert='ernie')
self.assertEquals(result, {'args': (1, 2),
'kwargs': {'bert': 'ernie'}})
-
- caught = False
- try:
- tp.run_in_thread(self._raise_valueerror)
- except ValueError:
- caught = True
- self.assertTrue(caught)
+ self.assertRaises(ValueError, tp.run_in_thread,
+ self._raise_valueerror)
def test_force_run_in_thread_without_threads(self):
# with zero threads, force_run_in_thread uses eventlet.tpool
@@ -2616,12 +2607,36 @@ class TestThreadpool(unittest.TestCase):
result = tp.force_run_in_thread(self._capture_args, 1, 2, bert='ernie')
self.assertEquals(result, {'args': (1, 2),
'kwargs': {'bert': 'ernie'}})
- caught = False
+ self.assertRaises(ValueError, tp.force_run_in_thread,
+ self._raise_valueerror)
+
+ def test_preserving_stack_trace_from_thread(self):
+ def gamma():
+ return 1 / 0 # ZeroDivisionError
+
+ def beta():
+ return gamma()
+
+ def alpha():
+ return beta()
+
+ tp = utils.ThreadPool(1)
try:
- tp.force_run_in_thread(self._raise_valueerror)
- except ValueError:
- caught = True
- self.assertTrue(caught)
+ tp.run_in_thread(alpha)
+ except ZeroDivisionError:
+ # NB: format is (filename, line number, function name, text)
+ tb_func = [elem[2] for elem
+ in traceback.extract_tb(sys.exc_traceback)]
+ else:
+ self.fail("Expected ZeroDivisionError")
+
+ self.assertEqual(tb_func[-1], "gamma")
+ self.assertEqual(tb_func[-2], "beta")
+ self.assertEqual(tb_func[-3], "alpha")
+ # omit the middle; what's important is that the start and end are
+ # included, not the exact names of helper methods
+ self.assertEqual(tb_func[1], "run_in_thread")
+ self.assertEqual(tb_func[0], "test_preserving_stack_trace_from_thread")
class TestAuditLocationGenerator(unittest.TestCase):