On Mar 7, 2009, at 1:31 AM, Shawn Wilsher wrote: > Hey all, > > I've been looking online for a bit trying to establish what > protections, if > any, are associated with sqlite3_stmt objects. It's clearly > documented that > sqlite3 objects' access is serialized across threads, but I cannot > find > anything about sqlite3_stmt. I don't actually care either way, but if > SQLite protects it internally, I don't want to add additional > overhead by > protecting it myself.
Each database connection (sqlite3) has associated with it a single mutex. Many of the operations on an sqlite3_step* object are protected internally by this mutex (i.e. sqlite3_step()). But some are not, especially the data access functions like sqlite3_data_count() etc. Accessing values using the sqlite3_column_XXX() API is nearly threadsafe. If some other thread calls sqlite3_step() to advance the statement while the first thread is calling sqlite3_column_XXX(), then you could conceivably get a problem. But multiple threads using the sqlite3_column_XXX() functions is safe. So I suppose the only correct answer is "no, they are not threadsafe objects". Why do you want to use a single sqlite3_stmt* from multiple threads at the same time? Dan. > Could someone please clarify this (and maybe add some documentation)? > > Cheers, > > Shawn Wilsher > Mozilla Developer > _______________________________________________ > sqlite-users mailing list > sqlite-users@sqlite.org > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
