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Proposal: Async Console I/O APIs #299
Description
Proposal
Async Console I/O APIs
Since now we can write async Task Main, I think it's necessary to add APIs to support cancellable async console I/O operations without needs of operating Console.In, Console.Out directly for converience.
Proposed APIs
public static class Console
{
+ public static Task WriteAsync(string content, CancellationToken cancellationToken);
+ // ... other overloads for char, int and etc
+ public static Task WriteLineAsync(T content, CancellationToken cancellationToken);
+ // ... other overloads for char, int and etc
+ public static Task<int> ReadKeyAsync(CancellationToken cancellationToken);
+ public static Task<string> ReadLineAsync(CancellationToken cancellationToken);
}
Activity
huoyaoyuan commentedon Nov 26, 2019
There are so many overloads on textwriter. Accessing
InorOutis just literally 3 or 4 characters without any code flow changes, and can be much shorter if saved as variable.Only
ReadKeyAsyncis really benificial.fbrosseau commentedon Nov 30, 2019
Also, at least under Windows, but I would assume other implementations are similar, the in/out streams are implemented as synchronous-only streams, so the proposal to have first-class async methods on Console would be a misleading hidden threadpool block.
Allow serving of unknown files (dotnet#299)
adamsitnik commentedon Nov 14, 2023
Console is not opened for async IO on Windows, but with #87103 and #72503 we should be able to get cancellation support on Windows. I wonder whether it would be possible to implement it on Unix.
cc @stephentoub @tmds
tmds commentedon Nov 16, 2023
These don't seem particularly useful: usually you want to block until the output was written.
These have a UX race between cancellation and the user providing input: was the input for the previous or the next caller?
If
ReadKeyAsyncincercepts (likeReadKey(incercept: true)) on cancellation the key could go back in the queue.I think we may perform the read on a separate thread where it blocks until there is input.