Patrik Jonsson wrote:
Hi,
I don't pretend to know how the boost thread functions work, but I've used them and haven't had any problems. Are you sure it's not just that the object is being copied 4 times and what you're seeing are the destructors for the copies? In your test code, you wouldn't be able to tell. According to the docs, the thread constructor makes at least one copy of its argument. Does your class have a working copy constructor?
Since boost::thread takes a boost::function, which copies it's functor when it is copied to preven dangling references - so in the second case writerClass is probably indeed being copied. 4 times does seem slightly odd I'll admit... but I suppose the boost::function is simply getting passed around a bit by value internally. If you create a copy constructor, it should show writerClass getting copied a few times. If you didn't want this behavior you'd use boost::ref IIRC: writerClass writer; boost::thread thrd2( boost::ref( writer ) );
and changed in the main() --> boost::thread thrd2(&writer); with --> boost::thread thrd2((writerClass()));
Everything works the same, but I have the destructor of wirterClass called 4 times, when constructing thrd2!!!
That's weird to me, but it's annoying because in my other program, the dtor destroys some member data, and the program crashes because of it. Why is the ~writerClass() called? is there maybe some exception thrown?? how can I solve the problem?
Again, probably due to the fact that writerClass is getting copied a few times. Adding an appropriate copy constructor should do the trick (e.g. deep copy pointed to data or use a boost::shared_ptr so that all the classes share a single version of the data, but don't delete it until the last instance dies) -Mike