problem demo - interrupting a read

please-close.zig

const std = @import("std");

const fs = std.fs;
const time = std.time;

pub const io_mode = .evented;

fn portReader(r: fs.File.Reader) !void {
    var buf = [_]u8{0} ** 1024;

    while (true) {
        std.debug.print("awaiting input\n", .{});
        const bytes = try r.read(buf[0..]);

        std.debug.print("bytes: {any}\n", .{bytes});
        if (bytes == 0) {
            break;
        }
        std.debug.print("{s}", .{buf[0..bytes]});
        // ... etc
    }
}

pub fn main() anyerror!void {
    const port = try fs.cwd().openFile("/dev/ttyACM0", .{});
    defer port.close();

    std.debug.print("port: {any}\n", .{port});

    var readerFrame = async portReader(port.reader());

    std.debug.print("sleeping 5s\n", .{});
    time.sleep(time.ns_per_s * 5);

    // What I really want to happen here is that the blocked read
    // above is interrupted and returns 0.
    // But it just keeps on being blocked.
    std.debug.print("closing port\n", .{});
    port.close();

    try await readerFrame;
    std.debug.print("done\n", .{});
}