Doing the latter - closing everything, forking, re-opening - is always going to be safe. Or if the parent isn't going to use the connection, just don't open the database until you're in the child after forking.
On Mon, Nov 11, 2019 at 8:08 AM Jukka Marin <jukka.ma...@jmp.fi> wrote: > On Fri, Nov 08, 2019 at 09:57:25AM +0200, Jukka Marin wrote: > > On Thu, Nov 07, 2019 at 09:26:46AM -0800, Shawn Wagner wrote: > > > This line stood out: > > > > > > > The main process opens the databases and then forks the other > processes > > > which can then perform database operations using the already opened > > > databases. > > > > > > From > > > > https://sqlite.org/howtocorrupt.html#_carrying_an_open_database_connection_across_a_fork_ > > > : > > > > > > > Do not open an SQLite database connection, then fork(), then try to > use > > > that database connection in the child process. All kinds of locking > > > problems will result and you can easily end up with a corrupt database. > > > SQLite is not designed to support that kind of behavior. Any database > > > connection that is used in a child process must be opened in the child > > > process, not inherited from the parent. > > > > > > In this kind of situation, I usually use pthread_atfork() callbacks to > > > automate closing databases and then re-opening them in the parent and > child. > > > > Okay, thanks! I suspected it could be something like this, but couldn't > > find anything in the SQLite docs. > > In some situations, my main process will have the databases opened before > it needs to fork a new child (this happens only if a child dies and > has to be restarted). If the child process immediately closes its copies > of the databases and then reopens them, will it be safe? > > Or does the main process need to close all databases, then fork, then > reopen the databases? > > Thanks again! > > Jukka Marin > _______________________________________________ > sqlite-users mailing list > sqlite-users@mailinglists.sqlite.org > http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users > _______________________________________________ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
