On Mar 4, 2009, at 8:31 AM, Marcus Grimm wrote:
> Richard,
> Thanks for looking into this.
>
> I've placed some debug output in the sqlite2_step function
> and I found that it returns SQLITE_MISUSE here:
>
> --
> static int sqlite3Step(Vdbe *p){
> sqlite3 *db;
> int rc;
>
> assert(p);
> if( p->magic!=VDBE_MAGIC_RUN )
> {
> return SQLITE_MISUSE;
> }
> --
What is the value of p->magic at the point of failure? (In hex, please)
>
>
> I have no idea what this MAGIC_RUN means.
>
> Does it indicate that infact I'm using an allready released
> statement ?
>
> Please note that I'm not able to reproduce the problem when
> I switch the shared cache off.
>
> Thank you
>
> Kind regards
>
> Marcus Grimm
>
>
> D. Richard Hipp wrote:
>> On Mar 4, 2009, at 5:19 AM, Marcus Grimm wrote:
>>
>>> Hi all,
>>>
>>> I'm doing a little stress test on a server application and run into
>>> a problem when two threads are trying to access the database.
>>> Here is the background:
>>> 1. shared cache is enabled prior open any DB connection.
>>> 2. Each thread then opens a DB connection.
>>> 3. Thread A just reads table entries continuosly by
>>> doing sqlite3_prepare_v2 and followed by some sqlite3_step to
>>> parse the result set.
>>> He then uses sqlite3_finalize and after a few ms he repeats
>>> everything.
>>> 4. Thread B is triggered to update or insert some a new values
>>> in some tables.
>>> To do so I obtain an EXCLUSIVE transaction, do the insert/update
>>> and COMIT.
>>>
>>> Now, a problem arises occasionally that thread A gets an
>>> SQLITE_MISUSE when
>>> trying to call sqlite3_step, most likely because thread B currently
>>> writes into
>>> the DB, I guess.
>>>
>>> Now, my question:
>>>
>>> How to handle the SQLITE_MISUSE ?
>>
>> My guess is that the SQLITE_MISUSE is being returned because you are
>> calling sqlite3_step() with a statement that has already been
>> destroyed by sqlite3_finalize().
>>
>>
>> D. Richard Hipp
>> d...@hwaci.com
>>
>>
>>
>> _______________________________________________
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>> http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
>>
>
> --
> Marcus Grimm, MedCom GmbH Darmstadt, Rundeturmstr. 12, 64283 Darmstadt
> Tel: +49(0)6151-95147-10
> Fax: +49(0)6151-95147-20
> --------------------------------------------------
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D. Richard Hipp
d...@hwaci.com
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