view tests/lockdelay.py @ 29494:3b5389ef5cfe

perf: define util.safehasattr forcibly for Mercurial earlier than 1.9.3

Before this patch, using util.safehasattr() prevents perf.py from
being loaded by Mercurial earlier than 1.9.3 (or 94b200a11cf7),
because util.safehasattr() isn't available in such Mercurial, even
though there are some code paths for Mercurial earlier than 1.9.3.

For example, setting "_prereadsize" attribute in perfindex() and
perfnodelookup() is effective only with Mercurial earlier than 1.8 (or
61c9bc3da402).

This patch is a preparation for using util.safehasattr() safely in
subsequent patches.

This patch defines util.safehasattr() forcibly without examining
whether it is available or not, because:

  - examining existence of "safehasattr" safely itself needs similar logic
  - safehasattr() is small enough to define locally

# Dummy extension that adds a delay after acquiring a lock.
#
# This extension can be used to test race conditions between lock acquisition.

from __future__ import absolute_import

import os
import time

from mercurial import (
    lock as lockmod,
)

class delaylock(lockmod.lock):
    def lock(self):
        delay = float(os.environ.get('HGPRELOCKDELAY', '0.0'))
        if delay:
            time.sleep(delay)
        res = super(delaylock, self).lock()
        delay = float(os.environ.get('HGPOSTLOCKDELAY', '0.0'))
        if delay:
            time.sleep(delay)
        return res

def extsetup(ui):
    lockmod.lock = delaylock