hg: obtain lock when creating share from pooled repo (issue5104)
There are race conditions between clients performing a shared clone
to pooled storage:
1) Clients race to create the new shared repo in the pool directory
2) 1 client is seeding the repo in the pool directory and another goes
to share it before it is fully cloned
We prevent these race conditions by obtaining a lock in the pool
directory that is derived from the name of the repo we will be
accessing.
To test this, a simple generic "lockdelay" extension has been added.
The extension inserts an optional, configurable delay before or after
lock acquisition. In the test, we delay 2 seconds after lock acquisition
in the first process and 1 second before lock acquisition in the 2nd
process. This means the first process has 1s to obtain the lock. There
is a race condition here. If we encounter it in the wild, we could
change the dummy extension to wait on the lock file to appear instead
of relying on timing. But that's more complicated. Let's see what
happens first.
"""
lsprofcalltree.py - lsprof output which is readable by kcachegrind
Authors:
* David Allouche <david <at> allouche.net>
* Jp Calderone & Itamar Shtull-Trauring
* Johan Dahlin
This software may be used and distributed according to the terms
of the GNU General Public License, incorporated herein by reference.
"""
from __future__ import absolute_import, print_function
def label(code):
if isinstance(code, str):
return '~' + code # built-in functions ('~' sorts at the end)
else:
return '%s %s:%d' % (code.co_name,
code.co_filename,
code.co_firstlineno)
class KCacheGrind(object):
def __init__(self, profiler):
self.data = profiler.getstats()
self.out_file = None
def output(self, out_file):
self.out_file = out_file
print('events: Ticks', file=out_file)
self._print_summary()
for entry in self.data:
self._entry(entry)
def _print_summary(self):
max_cost = 0
for entry in self.data:
totaltime = int(entry.totaltime * 1000)
max_cost = max(max_cost, totaltime)
print('summary: %d' % max_cost, file=self.out_file)
def _entry(self, entry):
out_file = self.out_file
code = entry.code
if isinstance(code, str):
print('fi=~', file=out_file)
else:
print('fi=%s' % code.co_filename, file=out_file)
print('fn=%s' % label(code), file=out_file)
inlinetime = int(entry.inlinetime * 1000)
if isinstance(code, str):
print('0 ', inlinetime, file=out_file)
else:
print('%d %d' % (code.co_firstlineno, inlinetime), file=out_file)
# recursive calls are counted in entry.calls
if entry.calls:
calls = entry.calls
else:
calls = []
if isinstance(code, str):
lineno = 0
else:
lineno = code.co_firstlineno
for subentry in calls:
self._subentry(lineno, subentry)
print(file=out_file)
def _subentry(self, lineno, subentry):
out_file = self.out_file
code = subentry.code
print('cfn=%s' % label(code), file=out_file)
if isinstance(code, str):
print('cfi=~', file=out_file)
print('calls=%d 0' % subentry.callcount, file=out_file)
else:
print('cfi=%s' % code.co_filename, file=out_file)
print('calls=%d %d' % (
subentry.callcount, code.co_firstlineno), file=out_file)
totaltime = int(subentry.totaltime * 1000)
print('%d %d' % (lineno, totaltime), file=out_file)