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Fix typos (#759)

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Rob Gries
2020-02-26 16:08:00 -05:00
committed by Philipp Oppermann
parent 817c0c56ab
commit ba6452c5b0
1 changed files with 2 additions and 2 deletions
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blog/content/second-edition/posts/12-async-await/index.md
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@@ -169,7 +169,7 @@ let file_content = loop {
Here we _actively_ wait for the future by calling `poll` over and over again in a loop. The arguments to `poll` don't matter here, so we omitted them. While this solution works, it is very inefficient because we keep the CPU busy until the value becomes available.
A more efficient approach could be to _block_ the current thread until the future becomes available. This is of course only possible if you have threads, so this solution does not work for kernel, at least not yet. Even on systems where blocking is supported, it is often not desired because it turns an asynchronous task into a synchronous task again, thereby inhibiting the potential performance benefits of parallel tasks.
A more efficient approach could be to _block_ the current thread until the future becomes available. This is of course only possible if you have threads, so this solution does not work for our kernel, at least not yet. Even on systems where blocking is supported, it is often not desired because it turns an asynchronous task into a synchronous task again, thereby inhibiting the potential performance benefits of parallel tasks.
#### Future Combinators
@@ -225,7 +225,7 @@ Manually writing combinator functions is difficult, therefore they are often pro
##### Advantages
The big advantage of future combinators is that they keep the operations asynchronous. In combination with asynchronous I/O interfaces, this approach can lead to very high performance. The fact that future combinators are implemented as normal structs with trait implementations allows the compiler to excessively optimizing them. For more details, see the [_Zero-cost futures in Rust_] post, which announced the addition of futures to the Rust ecosystem.
The big advantage of future combinators is that they keep the operations asynchronous. In combination with asynchronous I/O interfaces, this approach can lead to very high performance. The fact that future combinators are implemented as normal structs with trait implementations allows the compiler to excessively optimize them. For more details, see the [_Zero-cost futures in Rust_] post, which announced the addition of futures to the Rust ecosystem.
[_Zero-cost futures in Rust_]: https://aturon.github.io/blog/2016/08/11/futures/