| 23 Oct 2021 |
 dirbaio | does alloc still require nightly? :C | 00:54:13 |
| dirbaio | yep, for #![feature(alloc_error_handler)] | 00:54:42 |
| dirbaio | nostd_async doesn't require alloc, huh | 00:59:46 |
| dirbaio | * nostd_async doesn't require alloc, huh | 00:59:49 |
 ithinuel | So, overall, anyway, the embassy support is gated behind a feature.
novice users won't dig that far and won't have the trouble of switching to nightly.
More advanced users requiring async are likely already running on nightly so that probably won't be an issue there either.
Trying to build the example will trigger the error saying it requires the feature and enabling that feature on stable will trigger the error that certain features are only available on nightly. This should be enough to deter inexperienced users 😀 | 00:59:50 |
| dirbaio | which makes it unsound. use-after-free if you wake a task after dropping it | 01:00:44 |
| dirbaio | wakers are Send+Sync+'static so they can live forever | 01:11:04 |
| dirbaio | so either you require tasks to be 'static (what embassy does) | 01:11:17 |
| dirbaio | but to put a future in a static you need either type_alias_impl_trait, or ultra horrible unsafe hacks | 01:12:21 |
| dirbaio | or you refcount the tasks, like an Arc, where each Waker and JoinHandle counts as a reference (what tokio, async-std, smol etc do) | 01:12:31 |
| dirbaio | but that needs alloc | 01:12:42 |
| dirbaio | there is NO sane way to make an executor without either alloc or type_alias_impl_trait | 01:13:23 |
| dirbaio | and both are nightly-only | 01:13:29 |
| dirbaio | so... 🤷 | 01:13:37 |
| dirbaio | not exactly | 01:16:40 |
| dirbaio | you can make an "executor" like loop { fut.poll() } on stable | 01:16:49 |
| dirbaio | if you want to run just 1 future, no multtasking | 01:16:57 |
| dirbaio | * if you want to run just 1 future, no multtasking | 01:17:05 |
| ithinuel | can't you just
loop {
fut1.poll();
fut2.poll();
}
? 😀
| 01:18:05 |
| ithinuel | * can't you just
loop {
fut1.poll();
fut2.poll();
}
``` ?
| 01:18:09 |
| ithinuel | * can't you just
loop {
fut1.poll();
fut2.poll();
}
?
| 01:18:15 |
| ithinuel | * can't you just
loop {
fut1.poll();
fut2.poll();
}
?
| 01:18:25 |
| ithinuel | * can't you just
loop {
fut1.poll();
fut2.poll();
}
? 😀
| 01:18:37 |
| dirbaio | hehehe | 01:18:54 |
| dirbaio | that's like polling join(fut1, fut2) | 01:19:11 |
| dirbaio | so yeah you could glue all your app together in a single giant Future and then poll-loop that | 01:19:47 |
| dirbaio | * so yeah you could glue all your app together in a single giant Future and then poll-loop that | 01:19:48 |
| dirbaio | In reply to @dirbaio:matrix.org
there is NO sane way to make an executor without either alloc or type_alias_impl_trait by "executor" there I mean a "real" executor that tracks which tasks have been woken and only polls these | 01:21:03 |
| dirbaio | and puts the core to sleep if no tasks want to run | 01:21:46 |
 devsnek | you don't need alloc if you manually keep track of entries in a huge statically allocated slice | 04:45:26 |
