On Friday 16 January 2009 16:35, Nat Goodspeed wrote:
Johan Råde wrote:
Frank also mentioned the possibility of adding a thread safe version of boost::trackable based on boost::enable_shared_from_this. That would be a very valuable addition to the library.
Second that! While I love the generality of the explicit tracking, I've been jumping through some hoops trying to adapt existing Boost.Signals code that uses boost::trackable.
If signals2 could provide a thread-safe version of boost::trackable, it would make conversion a much easier "sell" within my organization.
I have added a thread-UNsafe boost::signals2::trackable to svn to ease porting of single-threaded Boost.Signals code that doesn't need to be made thread-safe. Would you give a little more detail on what parts of boost::trackable porting you've found the most painful? Because to get thread-safe connection management in any form you'd still have to make your objects owned by shared_ptr and deal with the "no shared_from_this() in constructors" issue, since I don't think the release version of enable_shared_from_this supports use in constructors yet. With respect to the "no shared_from_this() in constructors" issue, I've added a "deconstruct" factory function based on make_shared and Michael Marcin's make_shared_access patch. It constructs the shared_ptr with a single allocation like make_shared and calls postconstructible::postconstruct like deconstruct_ptr. Its use can be forced by making your constructors private and declaring the class boost::signals2::deconstruct_access a friend.