Distinguish datacheckums worker invocations more reliably In some corner cases, a new datachecksums worker could be launched while an old one was still running. If you're really unlucky, the old worker could set the worker_result in shared memory and mislead the launcher to think that a newer worker invocation completed successfully, even though it failed for some reason. That's highly unlikely to happen in practice as it requires several race conditions with workers and launchers starting, failing and succeeding and at the right moments. Nevertheless, better to tighten it up.
To distinguish different worker invocations, assign a unique 'worker_invocation' number every time a new worker is launched. In the worker, check that the invocation number matches before setting the worker result. This ensures that the result always belongs to the latest invocation. Reviewed-by: Daniel Gustafsson <[email protected]> Discussion: https://www.postgresql.org/message-id/[email protected] Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/a4f02cab4b97027b397d073f6174de8581befbfd Modified Files -------------- src/backend/postmaster/datachecksum_state.c | 99 +++++++++++++++++++++-------- 1 file changed, 73 insertions(+), 26 deletions(-)
