Hello again !  

I think that would be interesting to have functions similar to
sqlite3_next_stmt/sqlite3_finalize for extensions something like this:  


sqlite3_next_extension / sqlite3_finalize_extension  

?  

Cheers !  



>  Fri Sep 04 2015 5:13:23 pm CEST CEST from "Domingo Alvarez Duarte"
><sqlite-mail at dev.dadbiz.es>  Subject: Re: [sqlite] SQLite3 trunk error with
>old database with fts3/4
>
>  Hello again ! 
> 
> I looked at the documentaion again and realized that I was alread calling
> sqlite3_close_v2 the I commented out all of the sqlite3_next_stmt cleanup
>and
> no segfaults so far, I'll see if memory is released on a long running
>process
> to certify that everything is fine. 
> 
> Thanks a lot for your help ! 
> 
> 
> 
>  
>>Fri Sep 04 2015 4:57:57 pm CEST CEST from "Domingo Alvarez Duarte"
>> <sqlite-mail at dev.dadbiz.es> Subject: Re: [sqlite] SQLite3 trunk error with
>> old database with fts3/4
>> 
>> Hello ! 
>> 
>> I did something similar to your sugestion (sqlite3_next_stmt(db, NULL))?
>> and
>> it still segfaults. 
>> 
>> What you mention about fts3/4 having prepared statemtns that and somehow
>> I'm
>> doing a double free a good point. 
>> 
>> And will be sad to not be able to use sqlite3_next_stmt(db, NULL) to
>> finalize
>> any open preapred statemnt, because it's very handy when using
>>"exceptions"
>> and having a single point to do the cleanup. 
>> 
>> Can somehow sqlite3_prepare somehow have any extra parameter to indicated
>> that we are using it from an extension and somehow sqlite3_next_stmt
>>detect
>> it and skip it ? 
>> 
>> Or any way to safely have a central point to do a cleanup ? 
>> 
>> Cheers !
>> 
>> 
>>  
>>>Fri Sep 04 2015 4:44:02 pm CEST CEST from "Dan Kennedy"
>>> <danielk1977 at gmail.com> Subject: Re: [sqlite] SQLite3 trunk error with
>>>old
>>> database with fts3/4
>>> 
>>> On 09/04/2015 09:29 PM, Domingo Alvarez Duarte wrote:
>>> 
>>> 
>>>  
>>>>Hello again !
>>>> 
>>>> On mac os x some time ago I was getting segfaults here and tought that
>>>>it
>>>> was
>>>> caused by the way os x manage memory but it doesn't seem correct.
>>>> 
>>>> The error happens on this code that is called before call sqlite3_close:
>>>> 
>>>> sqlite3 *db = sdb->db;
>>>> sqlite3_stmt* statement = NULL;
>>>> int count = 0;
>>>> while ((statement = sqlite3_next_stmt(db, statement)))
>>>> {
>>>> //do no close statements because garbage collector will
>>>> do it
>>>> //on MacOSX we get segfaults finalizing statements here
>>>> printf("sq_sqlite3_close_release:stmt:%s\n",
>>>> sqlite3_sql(statement));
>>>> sqlite3_finalize(statement);
>>>> count++;
>>>> }
>>>> if (count) return sq_throwerror(v, _SC("closing database with
>>>> %d statements not closed."), count);
>>>> 
>>>> 
>>>> 

>>>  Hi,
>>> 
>>> Two problems:
>>> 
>>> After you have finalized a statement handle, it may not be passed to 
>>> sqlite3_next_stmt(). Change the while() line to:
>>> 
>>> while( (statement = sqlite3_next_stmt(db, NULL)) ){ ...
>>> 
>>> Another reason not to do this before calling sqlite3_close() is that the 
>>> FTS module may be managing some of these statement handles. So if you 
>>> finalize() them before sqlite3_close() is called, then when the FTS 
>>> module is shut down as part of the eventual sqlite3_close() call, it may 
>>> pass the same statement handle pointers to sqlite3_finalize() - similar 
>>> to a double-free of any other object or memory allocation. SQLite 
>>> includes checks to try to return SQLITE_MISUSE instead of crashing when 
>>> this happens, but they only work some of the time - this scenario can 
>>> still cause crashes or heap corruption.
>>> 
>>> A workaround is to call sqlite3_close() on the db, then do the above 
>>> only if it returns SQLITE_BUSY. This works because, even though it 
>>> fails, the first sqlite3_close() shuts down the FTS module - 
>>> guaranteeing that it is no longer holding pointers to statement handles.
>>> 
>>> Even better is not to leak statement handle pointers. The 
>>> sqlite3_next_stmt() API should really only be used to help track down 
>>> leaks, not to do cleanup.
>>> 
>>> Dan.
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>>  
>>>>  
>>>>>Fri Sep 04 2015 4:18:01 pm CEST CEST from "Domingo Alvarez Duarte"
>>>>> <sqlite-mail at dev.dadbiz.es> Subject: Re: [sqlite] SQLite3 trunk error
>>>>> with
>>>>> old database with fts3/4
>>>>> 
>>>>> Hello !
>>>>> 
>>>>> I'm not sure where the problem is but this code worked without any
>>>>> problem
>>>>> with previous sqlite3.
>>>>> 
>>>>> Here is a backtrace of a segfault using gdb (the line numbers will not
>>>>> match
>>>>> standard sqlite3.c because I have some custom extensions):
>>>>> 
>>>>> enter mutex 0x7fffe405f570 (1213663847) with nRef=1919906927
>>>>> 
>>>>> Program received signal SIGSEGV, Segmentation fault.
>>>>> [Switching to Thread 0x7ffff3c70700 (LWP 22336)]
>>>>> 0x0000000000479d85 in freeEphemeralFunction (db=0x7fffe4000078,
>>>>> pDef=0xaaaaaaaaaaaaaaaa)
>>>>> at sqlite3.c:66869
>>>>> 66869 if( ALWAYS(pDef) && (pDef->funcFlags & SQLITE_FUNC_EPHEM)!=0
>>>>> ){
>>>>> (gdb) bt
>>>>> #0 0x0000000000479d85 in freeEphemeralFunction (db=0x7fffe4000078,
>>>>> pDef=0xaaaaaaaaaaaaaaaa)
>>>>> at sqlite3.c:66869
>>>>> #1 0x0000000000479e39 in freeP4 (db=db at entry=0x7fffe4000078,
>>>>> p4type=-1431655766, p4=0x7fffe4181588)
>>>>> at sqlite3.c:66884
>>>>> #2 0x0000000000479f14 in vdbeFreeOpArray (db=0x7fffe4000078,
>>>>> aOp=0x7fffe40df508, nOp=<optimised out>)
>>>>> at sqlite3.c:66933
>>>>> #3 0x000000000047a01c in sqlite3VdbeClearObject (db=0x7fffe4000078,
>>>>> p=0x7fffe408ac88) at sqlite3.c:68920
>>>>> #4 0x000000000047a0c3 in sqlite3VdbeDelete (p=0x7fffe408ac88)
>>>>> at sqlite3.c:68941
>>>>> #5 0x00000000004e6044 in sqlite3VdbeFinalize (p=0x7fffe408ac88)
>>>>> at sqlite3.c:68861
>>>>> #6 0x00000000004e60cd in sqlite3_finalize (pStmt=0x7fffe408ac88)
>>>>> at sqlite3.c:70500
>>>>> 
>>>>> 
>>>>> 
>>>>> 
>>>>> 
>>>>>  
>>>>>>Fri Sep 04 2015 4:05:12 pm CEST CEST from "Dan Kennedy"
>>>>>> <danielk1977 at gmail.com> Subject: Re: [sqlite] SQLite3 trunk error with
>>>>>> old
>>>>>> database with fts3/4
>>>>>> 
>>>>>> On 09/04/2015 07:35 PM, Domingo Alvarez Duarte wrote:
>>>>>> 
>>>>>> 
>>>>>> 
>>>>>> 
>>>>>>  
>>>>>>>Hello !
>>>>>>> 
>>>>>>> After fix the index issues using an old sqlite3 executable (the trunk
>>>>>>> refuse
>>>>>>> to work on indexes created with single quotes on field names) I'm
>>>>>>> getting
>>>>>>> ocasionaly memory errors when using fts3/4 searches, see error below:
>>>>>>> 
>>>>>>> free(): corrupted unsorted chunks: 0x00007fa3a01073a0
>>>>>>> 
>>>>>>> 
>>>>>>> 
>>>>>>> 

>>>>>>  Is this error on the trunk or with the old version?
>>>>>> 
>>>>>> If it's on the trunk, is the error reproducible using the sqlite3
>>>>>>shell
>>>>>> tool?
>>>>>> 
>>>>>> If not, what does valgrind have to say about the app?
>>>>>> 
>>>>>> Thanks,
>>>>>> Dan.
>>>>>> 
>>>>>> _______________________________________________
>>>>>> sqlite-users mailing list
>>>>>> sqlite-users at mailinglists.sqlite.org
>>>>>> http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
>>>>>> 
>>>>>> 
>>>>>> 
>>>>>> 
>>>>>> 
>>>>>> 
>>>>>> 
>>>>>> 
>>>>>> 

>>>>>  _______________________________________________
>>>>> sqlite-users mailing list
>>>>> sqlite-users at mailinglists.sqlite.org
>>>>> http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
>>>>> 
>>>>> 
>>>>> 
>>>>> 
>>>>> 
>>>>> 
>>>>> 
>>>>> 

>>>>  _______________________________________________
>>>> sqlite-users mailing list
>>>> sqlite-users at mailinglists.sqlite.org
>>>> http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
>>>> 
>>>> 
>>>> 

>>>  _______________________________________________
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>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 

>>  ?
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>> 
>> 
>> 
>> 
>> 
>> 

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