Обсуждение: Is Backgroundworker.bgw_restart_time is defined in seconds?
Hi,
typedef struct BackgroundWorker
{
char bgw_name[BGW_MAXLEN];
char bgw_type[BGW_MAXLEN];
int bgw_flags;
BgWorkerStartTime bgw_start_time;
int bgw_restart_time; /* in seconds, or BGW_NEVER_RESTART */
char bgw_library_name[BGW_MAXLEN];
char bgw_function_name[BGW_MAXLEN];
Datum bgw_main_arg;
char bgw_extra[BGW_EXTRALEN];
pid_t bgw_notify_pid; /* SIGUSR1 this backend on start/stop */
} BackgroundWorker;
static bool
SanityCheckBackgroundWorker(BackgroundWorker *worker, int elevel)
{
... ...
if ((worker->bgw_restart_time < 0 &&
worker->bgw_restart_time != BGW_NEVER_RESTART) ||
(worker->bgw_restart_time > USECS_PER_DAY / 1000))
> The Backgroundworker.bgw_restart_time is defined in seconds,
> so should it be "USECS_PER_DAY / 1000,000" here instead of "USECS_PER_DAY / 1000"?
> Or am I getting it wrong?
{
ereport(elevel,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("background worker \"%s\": invalid restart interval",
worker->bgw_name)));
return false;
}
... ...}
Regards!
> On 26 Aug 2021, at 09:38, constzl <const_sunny@126.com> wrote:
> if ((worker->bgw_restart_time < 0 &&
> worker->bgw_restart_time != BGW_NEVER_RESTART) ||
> (worker->bgw_restart_time > USECS_PER_DAY / 1000))
>
> > The Backgroundworker.bgw_restart_time is defined in seconds,
> > so should it be "USECS_PER_DAY / 1000,000" here instead of "USECS_PER_DAY / 1000"?
> > Or am I getting it wrong?
bgw_restart_time is defined as "It can be any positive value” in the docs, see:
https://www.postgresql.org/docs/current/bgworker.html
My reading of the above code is that is tries to catch nonsensical values, not
to cap it to enforce restarts within a 24h period.
--
Daniel Gustafsson https://vmware.com/
Yes, I got it wrong. You're right. Thank you for your explanation!<br/><br/>Best Regards, At 2021-08-26 16:09:36, "Daniel Gustafsson" <daniel@yesql.se> wrote: >> On 26 Aug 2021, at 09:38, constzl <const_sunny@126.com> wrote: > >> if ((worker->bgw_restart_time < 0 && >> worker->bgw_restart_time != BGW_NEVER_RESTART) || >> (worker->bgw_restart_time > USECS_PER_DAY / 1000)) >> >> > The Backgroundworker.bgw_restart_time is defined in seconds, >> > so should it be "USECS_PER_DAY / 1000,000" here instead of "USECS_PER_DAY / 1000"? >> > Or am I getting it wrong? > >bgw_restart_time is defined as "It can be any positive value” in the docs, see: > > https://www.postgresql.org/docs/current/bgworker.html > >My reading of the above code is that is tries to catch nonsensical values, not >to cap it to enforce restarts within a 24h period. > >-- >Daniel Gustafsson https://vmware.com/ > >
Daniel Gustafsson <daniel@yesql.se> writes:
>> On 26 Aug 2021, at 09:38, constzl <const_sunny@126.com> wrote:
>> if ((worker->bgw_restart_time < 0 &&
>> worker->bgw_restart_time != BGW_NEVER_RESTART) ||
>> (worker->bgw_restart_time > USECS_PER_DAY / 1000))
> My reading of the above code is that is tries to catch nonsensical values, not
> to cap it to enforce restarts within a 24h period.
This may be intended to guard against integer overflows later (he guesses
without having read the code).
regards, tom lane