Re: [sqlite] SQLITE_ENABLE_MEMORY_MANAGEMENT: AV when Open / Close DB in different threads

[Rob Lohman]

Hi Ralf,

If I remember correctly you cannot use a SQLite database handle
across threads. Each thread will need to open (and close) the
database itself.
Cheers,

Rob

----- Original Message ----- 
From: "Ralf Junker" <[EMAIL PROTECTED]>
To: <sqlite-users@sqlite.org>
Sent: Tuesday, March 21, 2006 12:02 PM
Subject: [sqlite] SQLITE_ENABLE_MEMORY_MANAGEMENT: AV when Open / Close DB 
in different threads


Hello,

I am using SQLite compiled with SQLITE_ENABLE_MEMORY_MANAGEMENT on Win32.

I execute the following psydocode, all with same DB handle:

* In application's main thread: sqlite3_open
* Create a new thread
* In new thread: sqlite3_close

This creates an access violation in pager.c, lines 2065 to 2076:

#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
 /* Remove the pager from the linked list of pagers starting at
 ** ThreadData.pPager if memory-management is enabled.
 */
 if( pPager==pTsd->pPager ){
   pTsd->pPager = pPager->pNext;
 }else{
   Pager *pTmp;
   for(pTmp = pTsd->pPager; pTmp->pNext!=pPager; pTmp=pTmp->pNext);
   pTmp->pNext = pPager->pNext;
 }
#endif

While I understand from the FAQ that it might be problematic to use more 
than one thread with SQLITE_ENABLE_MEMORY_MANAGEMENT, I wonder if SQLite 
should cause an AV in this case?

I even found that other SQL instructions, like INSERT, work fine when 
called from the 2nd thread.

Could anybody help, please?

Thanks & regards,

Ralf