On Fri, 2005-04-15 at 14:44 +0300, Cosmin Vlasiu wrote: > Hello to everyone, > > I have a question... regarding multi-threading... > the question is for microsoft windows (a visual c++ application)... I saw > the documentation > and I understood that for microsoft OS, the multi-threading is > enabled by default. > So, of course I start two threads, both of them make a loop into a > "recordset". > the first thread it works good, but the second, no way. I made kind of > research > in the documentation and I observed that I have to make new connections for > each thread. > All donne. But when I run the application I got the same problem. > In the second thread the sqlite3_prepare function always return the 21 value > that means SQLITE_MISUSE, because sqlite3SafetyOn retun 1. > > Can somebody tells me if there is a solution for that problem? >
Two separate threads may not use the same database handle at the same time. If they do, the SQLITE_MISUSE value is often returned. Separate threads should have their own database handles. I know you said above that you are using separate database handles in your two threads. But probably there is a bug in your code that is preventing this from happening really. My advice to *all* programmers is to never use more than one thread in the same address space. I have never in 20 years worked on a multiple threaded program that actually got all of the threading issues right. There are always subtle bugs that cause error that are very difficult to reproduce and fix. Multithreading is the fastest road to buggy code that I know of. Avoid it. If you absolutely, positively must have multiple threads of control, put each thread in its own address space (make it a process.) -- D. Richard Hipp <[EMAIL PROTECTED]>
