On 16/02/2020 21.33, Max Paperno wrote: > Happened to stumble upon this clazy check while searching on a > completely different issue. > Seems to explain the reasoning pretty well. > > https://github.com/KDE/clazy/blob/master/docs/checks/README-connect-3arg-lambda.md
Thanks for sharing the link! This is good information for anyone that doesn't understand the issue. One particular point to note is... > On 2/15/2020 12:40 AM, Max Paperno wrote: >> On 2/14/2020 11:19 PM, Tony Rietwyk wrote (in part): >>> In the shorter overload, I would assume that the context is simply >>> the current thread object. ...that this is wrong; a 3-arg connection *doesn't have* a context argument. The connection will exist for as long as the sending object, and you *don't know what thread it will execute in*. Seriously. Let that sink in. "Oh, well, it will run in the sender's thread," I hear you thinking. NO! You *don't know that*! I've written code that invokes signals in a thread other than the one to which the owning object belongs. (Typically, for objects whose purpose is to manage a worker thread.) With AutoConnection and a receiving context this is generally safe (in fact, it is often the *purpose* of such code to use the signals to pass data across threads), but if you don't supply a context, your code might suddenly execute in what was supposed to be a private worker thread. Don't use context-free connections. Just don't ;-). -- Matthew _______________________________________________ Interest mailing list Interest@qt-project.org https://lists.qt-project.org/listinfo/interest
