From 380bb53a423a4660f14c81448ef3f19660feac82 Mon Sep 17 00:00:00 2001
From: Michael Hanselmann <hansmi@google.com>
Date: Tue, 10 Jan 2012 15:20:05 +0100
Subject: [PATCH] utils.ResetTempfileModule: Improve performance
This function is called for after every fork (e.g. for handling an RPC
request). With the changes in this patch generating the next random
filename is about 30% faster.
Signed-off-by: Michael Hanselmann <hansmi@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>
---
lib/utils/wrapper.py | 16 +++++++++-------
1 file changed, 9 insertions(+), 7 deletions(-)
diff --git a/lib/utils/wrapper.py b/lib/utils/wrapper.py
index 256d2f1d6..55cfbf214 100644
--- a/lib/utils/wrapper.py
+++ b/lib/utils/wrapper.py
@@ -171,7 +171,7 @@ def GetClosedTempfile(*args, **kwargs):
return path
-def ResetTempfileModule():
+def ResetTempfileModule(_time=time.time):
"""Resets the random name generator of the tempfile module.
This function should be called after C{os.fork} in the child process to
@@ -182,13 +182,15 @@ def ResetTempfileModule():
"""
# pylint: disable=W0212
- if hasattr(tempfile, "_once_lock") and hasattr(tempfile, "_name_sequence"):
- tempfile._once_lock.acquire()
+ try:
+ lock = tempfile._once_lock
+ lock.acquire()
try:
- # Reset random name generator
- tempfile._name_sequence = None
+ # Re-seed random name generator
+ if tempfile._name_sequence:
+ tempfile._name_sequence.rng.seed(hash(_time()) ^ os.getpid())
finally:
- tempfile._once_lock.release()
- else:
+ lock.release()
+ except AttributeError:
logging.critical("The tempfile module misses at least one of the"
" '_once_lock' and '_name_sequence' attributes")
--
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