yeah sure. So I was doing some thinking while stuck in traffic and I wondered if there's a way to "wait" for the condition that GetMessage() wouldn't block. It looks like MsgWaitForMultipleObjectsEx() might allow me to do so. If so, that would be the perfect solution. I could in a single function wait for notification that either 1) there's a win32 event to be processed or 2) there's trio activity to process. Furthermore, WM_USER would be left available for application use.
plus I think it would take fewer lines of code than a WM_USER implementation
But I think you can at least use a custom message type to avoid claiming
WM_USER?
this shouldn't take that much of your time, and I don't know anyone better to ask
for the rest of the upcoming PR series, I can have other people review them
I don't want to impose, so if you feel this is awkward for you or you don't have the time or energy, that's fine too
@njsmith it may not be shorter, but I think it definitely is less invasive on win32 application structure: https://gist.github.com/remdragon/6dd5c70455ff6f499336f4f192dec36b
I don't see how splitting those further into several commits makes it easier to review
at least I just look at the changed files as a whole
it's a PITA when trying to make it work with static typing
@njsmith I have a question. In trio, both tasks that are spawned trough a nursery and
awaited coroutines are cancellable. How do you achieve that? I guess that tasks that are spawned have a specific flag (like spawned=True) but how do you get coroutines that are called with the await syntax into task objects?
@richardsheridan the way I understand guest mode it doesn't need to. trio will call run_sync_soon_threadsafe() with a callable when it needs attention. and the callable provided to that function doesn't need to be awaited. From what I can tell this complies with trio's guest mode, but I haven't tried it yet
I think trio probably does some task switching magic when it gets those callbacks
We could also make a simpler version that just returns a MSG object once one has been received. That way the function would act like a drop-in replacement for GetMessage() itself and app developers can still use their own win32 event loop logic. I think I could also emulate PeekMessage... hmm..
I mean could something go wrong because of using
AsyncExitStack with Nursery. I don't know how fragile nurseries are. :smile:
@mozesa It’s fine as long as you use the AsyncExitStack in a way that matches something you could theoretically do with a series of async with statements. But AsyncExitStack combined with async with statements allows you to express other patterns too, and some of those won’t work, like “enter nursery 1, enter nursery 2, leave nursery 1, leave nursery 2” in that order.
@nocturn9x
await doesn’t create a new task — it’s just a function call. It is not actually even possible for Trio to do something on every await, just like you can’t make Python do something on every function call. One task is associated with the entire async callstack, starting with the thing that was spawned using nursery.start_soon or trio.run and ending with the Trio primitive that it’s currently waiting on. (At the lowest level, almost all Trio programs use only two such primitives: wait_task_rescheduled and cancel_shielded_checkpoint. There’s one more used only in rather obscure cases. See trio/_core/_traps.py.)
one: it arranges your tasks in a tree-oh
two: it’s based on three fundamental concepts: async functions, cancel scopes, and nurseries
IIRC in the very earliest stages of development (pre 0.1.0) it was called “oratorio”
but yeah it's just a name, there's no deep meaning
(iirc the name actually predates the discovery of nurseries, so the "alternative explanations" really are just happy accidents)
thanks both. so the X here is that qtrio is still 'just a name' to me rather than something i particularly like :] and i'm indulging since i think i'm close to a first release. triq was offered up by one of the existing qt/trio projects. quattro is available. quartet is namesquatted from 2017 so kinda available, sorta. it seems like there's value to both 'relating' to the name trio and also being different by more than just an extra q. and from two: above i could see 'widgets' being a fourth thing. i'm stuck between 'meh' and 'stop bikeshedding'.
now it's qtractor lel