diff --git a/src/part-guide/more-async-await.md b/src/part-guide/more-async-await.md index f2ee347e..6b03b86c 100644 --- a/src/part-guide/more-async-await.md +++ b/src/part-guide/more-async-await.md @@ -24,7 +24,7 @@ Blocking and cancellation are important to keep in mind when programming with as We say a thread (note we're talking about OS threads here, not async tasks) is blocked when it can't make any progress. That's usually because it is waiting for the OS to complete a task on its behalf (usually I/O). Importantly, while a thread is blocked, the OS knows not to schedule it so that other threads can make progress. This is fine in a multithreaded program because it lets other threads make progress while the blocked thread is waiting. However, in an async program, there are other tasks which should be scheduled on the same OS thread, but the OS doesn't know about those and keeps the whole thread waiting. This means that rather than the single task waiting for its I/O to complete (which is fine), many tasks have to wait (which is not fine). -We'll talk soon about non-blocking/async I/O. For now, just know that non-blocking I/O is I/O which the async runtime knows about and so will only the current task will wait, the thread will not be blocked. It is very important to only use non-blocking I/O from an async task, never blocking I/O (which is the only kind provided in Rust's standard library). +We’ll talk soon about non-blocking/async I/O. For now, just know that non-blocking I/O is I/O that the async runtime is aware of, so only the current task waits; the thread itself is not blocked. It is very important to only use non-blocking I/O from an async task, never blocking I/O (which is the only kind provided in Rust's standard library). ### Blocking computation