Re: [PATCH] lock_timeout and common SIGALRM framework

Hi,

2012-04-04 12:30 keltezéssel, Boszormenyi Zoltan írta:
> Hi,
>
> attached is a patch to implement a framework to simplify and
> correctly nest multiplexing more than two timeout sources
> into the same SIGALRM signal handler.
>
> The framework is using a new internal API for timeouts:
>
> bool enable_timeout(TimeoutName tn, int delayms);
> bool disable_timeout(TimeoutName tn, bool keep_indicator);
> bool disable_all_timeouts(bool keep_indicators);
>
> A timeout source has these features to allow different initialization,
> cleanup and check functions and rescheduling:
>
> typedef void (*timeout_init)(TimestampTz, TimestampTz);
> typedef void (*timeout_destroy)(bool);
> typedef bool (*timeout_check)(void);
> typedef TimestampTz (*timeout_start)(void);
>
> typedef struct {
>         TimeoutName     index;
>         bool            resched_next;
>         timeout_init    timeout_init;
>         timeout_destroy timeout_destroy;
>         timeout_check   timeout_check;
>         timeout_start   timeout_start;
>         TimestampTz     fin_time;
> } timeout_params;
>
> This makes it possible to differentiate between the standby and
> statement timeouts, regular deadlock and standby deadlock using
> the same signal handler function.
>
> And finally, this makes it possible to implement the lock_timeout
> feature that we at Cybertec implemented more than 2 years ago.
>
> The patch also adds two new tests into prepared_xacts.sql to trigger
> the lock_timeout instead of statement_timeout.
>
> Documentation and extensive comments are included.

Second version. Every timeout-related functions are now in a separate
source file, src/backend/storage/timeout.c with accessor functions.
There are no related global variables anymore, only the GUCs.

>
> Best regards,
> Zoltán Böszörményi


--
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Zoltán Böszörményi
Cybertec Schönig&  Schönig GmbH
Gröhrmühlgasse 26
A-2700 Wiener Neustadt, Austria
Web: http://www.postgresql-support.de
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