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Fix duplicated 'the the'

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Philipp Oppermann
2020-03-28 13:38:42 +01:00
parent a04926ae4d
commit 2966752b73
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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@@ -1570,7 +1570,7 @@ Note that reusing wakers like this is not possible for all waker implementations
#### Waker Design
The job of the waker is to push the ID of the woken task to the `wake_queue` of the executor. We implement this by creating a new `TaskWaker` struct that stores the task ID and a reference to the the `wake_queue`:
The job of the waker is to push the ID of the woken task to the `wake_queue` of the executor. We implement this by creating a new `TaskWaker` struct that stores the task ID and a reference to the `wake_queue`:
```rust
// in src/task/executor.rs
@@ -1625,7 +1625,7 @@ impl Wake for TaskWaker {
The trait is still unstable, so we have to add **`#![feature(wake_trait)]`** to the top of our `lib.rs` to use it. Since wakers are commonly shared between the executor and the asynchronous tasks, the trait methods require that the `Self` instance is wrapped in the [`Arc`] type, which implements reference-counted ownership. This means that we have to move our `TaskWaker` to an `Arc` to in order to call them.
The difference between the `wake` and `wake_by_ref` methods is that the latter only requires a reference the the `Arc`, while the former takes ownership of the `Arc` and thus often requires an increase of the reference count. Not all types support waking by reference, so implementing the `wake_by_ref` method is optional, however it can lead to better performance because it avoids unnecessary reference count modifications. In our case, we can simply forward both trait methods to our `wake_task` function, which requires only a shared `&self` reference.
The difference between the `wake` and `wake_by_ref` methods is that the latter only requires a reference the `Arc`, while the former takes ownership of the `Arc` and thus often requires an increase of the reference count. Not all types support waking by reference, so implementing the `wake_by_ref` method is optional, however it can lead to better performance because it avoids unnecessary reference count modifications. In our case, we can simply forward both trait methods to our `wake_task` function, which requires only a shared `&self` reference.
##### Creating Wakers