Re: [PATCH] lock_timeout and common SIGALRM framework

2012-04-04 15:17 keltezéssel, Boszormenyi Zoltan írta:
> 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.

3rd and (for now) final version. Tidied comments, the time checks in
Check*() functions and function order in timeout.c.

>
>>
>> Best regards,
>> Zoltán Böszörményi
>
>
>
>


-- 
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Zoltán Böszörményi
Cybertec Schönig&  Schönig GmbH
Gröhrmühlgasse 26
A-2700 Wiener Neustadt, Austria
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