[Python-checkins] bpo-31234: threading_cleanup() now warns immediately (#3138)

Wed Sep 13 16:42:03 EDT 2017

https://github.com/python/cpython/commit/ace1ecc00b35a8b1dc6e352d547dde07913017bb
commit: ace1ecc00b35a8b1dc6e352d547dde07913017bb
branch: master
author: Victor Stinner <victor.stinner at gmail.com>
committer: GitHub <noreply at github.com>
date: 2017年09月13日T13:42:00-07:00
summary:
bpo-31234: threading_cleanup() now warns immediately (#3138)
support.threading_cleanup() waits for 1 second before emitting a
warning if there are threads running in the background. With this
change, it now emits the warning immediately, to be able to catch
bugs more easily.
files:
M Lib/test/support/__init__.py

diff --git a/Lib/test/support/__init__.py b/Lib/test/support/__init__.py
index f57b2517792..df235050ae2 100644
--- a/Lib/test/support/__init__.py
+++ b/Lib/test/support/__init__.py
@@ -2030,22 +2030,32 @@ def threading_cleanup(*original_values):
 global environment_altered
 
 _MAX_COUNT = 100
- t0 = time.monotonic()
+
 for count in range(_MAX_COUNT):
 values = _thread._count(), threading._dangling
 if values == original_values:
 break
+
+ if not count:
+ # Display a warning at the first iteration
+ environment_altered = True
+ dangling_threads = values[1]
+ print("Warning -- threading_cleanup() failed to cleanup "
+ "%s threads (count: %s, dangling: %s)"
+ % (values[0] - original_values[0],
+ values[0], len(dangling_threads)),
+ file=sys.stderr)
+ for thread in dangling_threads:
+ print(f"Dangling thread: {thread!r}", file=sys.stderr)
+ sys.stderr.flush()
+
+ # Don't hold references to threads
+ dangling_threads = None
+ values = None
+
 time.sleep(0.01)
 gc_collect()
- else:
- environment_altered = True
 
- dt = time.monotonic() - t0
- print("Warning -- threading_cleanup() failed to cleanup %s threads "
- "after %.0f sec (count: %s, dangling: %s)"
- % (values[0] - original_values[0], dt,
- values[0], len(values[1])),
- file=sys.stderr)
 
 def reap_threads(func):
 """Use this function when threads are being used. This will
