[Interest] QSqlDatabase and threads

[Mark Brand]

> On Thursday 30 May 2013 18:03:15 Witold E Wolski wrote:
> 
> 
> I am using threading to speed up compuation. Each thread produces some
> results which I would like to store in a sqlite file.
> 
> 
> 
> My idea is to have something like an monitor object which has an 
> QSqlDatabase member and a insert method which is synchronized using a mutex.
> 
> 
> 
> The problem I am  actually running into is that the QSqlDatabase member gets
> ??? once the pointer to the Monitor object is passed into to the threads.
> 

It is not safe to access a QSqlDatabase from more than one thread, except for 
clone(). However,  sqlite itself is thread-safe. There's nothing wrong with a 
separate QSqlDatabase object in each thread opening its own connection to the 
same sqlite database. Let sqlite solve your concurrency problem. Sqlite is in 
a better position to manage concurrent database access than your application 
could ever hope to be, since it can do it at the level of individual database 
objects.

Mark