test-run-tests: stabilize the test (
issue5735)
Previously there is a race condition because things happen in this order:
1. Check shouldStop
2. If shouldStop is false, print the diff
3. Call fail() -> set shouldStop
The check and set should really happen in a same critical section.
This patch adds a lock to address the issue.
Test Plan:
Run `run-tests.py -l test-run-tests.t` 20 times on gcc112 and the race
condition does not reproduce.
Differential Revision: https://phab.mercurial-scm.org/D1830
{
"conduit_uri": "https://phab.mercurial-scm.org/api",
"repository.callsign": "HG",
"arc.land.onto.default": "@",
"base": "hg:.^"
}