On Saturday 10 February 2007 01:48 am, Timmo Stange wrote:
Timmo Stange wrote:
I've come across another problem that I find difficult to solve: Since signals are not copyable, the current implementation reference-wraps them when they're used as a slot target. The proper lifetime-dependency is established by signals being trackable subclasses, but we agreed that this won't work with thread-safe signals. Our weak_ptr-based solution doesn't work well when the tracked object is the actual target function object. Any suggestions?
I think I might have found a solution, if not a particularly beautiful one: With "signal for a slot" being handled as a special case anyway, I can create a "counterfeit copy" of the signal with the original signal object controlling the state and the counterfeit just sharing the implementation. When the original copy goes out of scope, all slots will be disconnected. The rest can be handled with some additional functionality in the tracking code.
If the signal is implemented with a pimpl via a shared_ptr, couldn't boost::track just store a weak_ptr to the pimpl in the special case of a signal argument? The signal could invoke the the boost::tracked by using the get_pointer() function and invoking it as a pointer to a function object (assuming the pimpl provides an operator() member function). Is that is what you are already suggesting? -- Frank