Hello, I'm working on a C++ application under WinCE (file system is TexFAT), with SQLite (actually version 3.6.11, but phenomenon is reproduced with 3.6.23) with the following C++ wrapper : http://www.alhem.net/project/sqlite/index.html . There's only one database with three tables (file is around 40KB, not so many entries!). The application has two same priority threads (and also the main thread of the application) , one is only reading the DB, the second one is reading or writing. (Because of some constraints, I cannot store many writings in order to do them at once using only one transaction, so I have to do each one of them as soon as possible). The C++ wrapper handles concurrent accesses through a Mutex (both threads are naturally using the same Database instance) : each new Query object locks the Database instance (and unlocks it in destructor). Then, there can't be two Query instances at a time refering to the same Database (I checked with traces & asserts, everything is correct).
My problem is the following : some writings or readings fail : SQLite returns the SQLITE_BUSY error. I found on SQLite website that locking mecanism is available with THREADSAFE preprocessor flag set at 1, but even then I can reproduce the issue. Also, I've changed the db opening from sqlite3_open to sqlite_open_v2 with flags (SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE | SQLITE_OPEN_FULLMUTEX) : still unsuccessful... Do you have any suggestion, as I'm getting stuck ? [Additionnal question : I've developped a test application in order to reproduce the above case. Once I stop this application, and thus the two threads accessing the db, I can see the journal file being created/deleted for seconds, depending on how long I kept the threads alive. As the C++ wrapper is fully synchronous, I don't understand why there are still accesses to the db! Is there any cache mecanism into SQLite ?] Thanks in advance for any answer ! Best regards, Aymerik _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
