Mercurial > hg
view hgdemandimport/tracing.py @ 49991:3997c64eff8b
test: use a more direct approach to test racy mutation
The previous test was relying on implementation details and harder to maintain.
The new version is closer to the initial intend : "What happens the file get overwritten from under the current process"
This change is motivated by further changes around the transaction and dirstate
logic that would break the fragile equilibrium that existed before this patch.
Making this change early make it easier to review on its own and remove noise
in future larger changes.
author | Pierre-Yves David <pierre-yves.david@octobus.net> |
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date | Tue, 07 Feb 2023 13:14:59 +0100 |
parents | 6000f5b25c9b |
children |
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# Support code for event tracing in Mercurial. Lives in demandimport # so it can also be used in demandimport. # # Copyright 2018 Google LLC. # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. import contextlib import os _pipe = None _checked = False _session = 'none' def _isactive(): global _pipe, _session, _checked if _pipe is None: if _checked: return False _checked = True if 'HGCATAPULTSERVERPIPE' not in os.environ: return False _pipe = open(os.environ['HGCATAPULTSERVERPIPE'], 'w', 1) _session = os.environ.get('HGCATAPULTSESSION', 'none') return True @contextlib.contextmanager def log(whencefmt, *whenceargs): if not _isactive(): yield return whence = whencefmt % whenceargs try: # Both writes to the pipe are wrapped in try/except to ignore # errors, as we can see mysterious errors in here if the pager # is active. Presumably other conditions could trigger # problems too. try: _pipe.write('START %s %s\n' % (_session, whence)) except IOError: pass yield finally: try: _pipe.write('END %s %s\n' % (_session, whence)) except IOError: pass def counter(label, amount, *labelargs): if not _isactive(): return l = label % labelargs # See above in log() for why this is in a try/except. try: _pipe.write('COUNTER %s %d %s\n' % (_session, amount, l)) except IOError: pass