sam_oneal/ziglings
1
0
Fork 0
mirror of https://codeberg.org/ziglings/exercises.git synced 2026-06-08 07:50:00 +00:00
Code Issues Packages Projects Releases Wiki Activity

revival of the async-io functions

Browse Source
This commit is contained in:
Chris Boesch
2026-04-01 22:28:37 +02:00
parent 3056a2b544
commit 77d3b684cb
3 changed files with 123 additions and 90 deletions
Download Patch File Download Diff File Expand all files Collapse all files

71
build.zig
View File

@@ -75,6 +75,8 @@ pub const Exercise = struct {
/// Hint to the user, why this has been skipped
skip_hint: ?[]const u8 = null,
timestamp: bool = false,
/// Returns the name of the main file with .zig stripped.
pub fn name(self: Exercise) []const u8 {
return std.fs.path.stem(self.main_file);
@@ -435,11 +437,30 @@ const ZiglingStep = struct {
result.stderr;
// Validate the output.
var exercise_output = self.exercise.output;
// Insert timestamp for exercise 84
if (self.exercise.timestamp) {
var ts_buf: [20]u8 = undefined;
const timestamp = std.fmt.bufPrint(&ts_buf, "{}", .{std.Io.Timestamp.now(io, .real).toSeconds()}) catch unreachable;
var buf: [100]u8 = undefined;
const prefix_len = 14;
const placeholder_len = 11;
@memcpy(buf[0..prefix_len], exercise_output[0..prefix_len]);
@memcpy(buf[prefix_len..][0..timestamp.len], timestamp);
const suffix = exercise_output[prefix_len + placeholder_len ..];
const suffix_dest_start = prefix_len + timestamp.len;
@memcpy(buf[suffix_dest_start..][0..suffix.len], suffix);
const total_len = prefix_len + timestamp.len + suffix.len;
exercise_output = buf[0..total_len];
}
// NOTE: exercise.output can never contain a CR character.
// See https://ziglang.org/documentation/master/#Source-Encoding.
const output = trimLines(b.allocator, raw_output) catch @panic("OOM");
const exercise_output = self.exercise.output;
if (!std.mem.eql(u8, output, self.exercise.output)) {
if (!std.mem.eql(u8, output, exercise_output)) {
const red = red_bold_text;
const reset = reset_text;
@@ -698,7 +719,7 @@ const exercises = [_]Exercise{
\\most part, you'll be taking directions from the Zig
\\compiler itself.)
\\
,
, // pay attention to the comma
},
.{
.main_file = "002_std.zig",
@@ -730,7 +751,7 @@ const exercises = [_]Exercise{
\\Ziggy played guitar
\\Jamming good with Andrew Kelley
\\And the Spiders from Mars
,
, // pay attention to the comma
.hint = "Please fix the lyrics!",
},
.{
@@ -867,7 +888,7 @@ const exercises = [_]Exercise{
\\ <span style="color: #00ff00">Green</span>
\\ <span style="color: #0000ff">Blue</span>
\\</p>
,
, // pay attention to the comma
.hint = "I'm feeling blue about this.",
},
.{
@@ -879,7 +900,7 @@ const exercises = [_]Exercise{
.output =
\\Character 1 - G:20 H:100 XP:10
\\Character 2 - G:10 H:100 XP:20
,
, // pay attention to the comma
},
.{
.main_file = "039_pointers.zig",
@@ -903,7 +924,7 @@ const exercises = [_]Exercise{
.output =
\\Wizard (G:10 H:100 XP:20)
\\ Mentor: Wizard (G:10000 H:100 XP:2340)
,
, // pay attention to the comma
},
.{
.main_file = "044_quiz5.zig",
@@ -947,7 +968,7 @@ const exercises = [_]Exercise{
.output =
\\Hand1: A 4 K 8
\\Hand2: 5 2 Q J
,
, // pay attention to the comma
},
.{
.main_file = "053_slices2.zig",
@@ -1043,7 +1064,10 @@ const exercises = [_]Exercise{
.main_file = "073_comptime8.zig",
.output = "My llama value is 25.",
},
.{ .main_file = "074_comptime9.zig", .output = "My llama value is 2.", .skip = false, .skip_hint = "This is actually correct as it is. :-)" },
.{
.main_file = "074_comptime9.zig",
.output = "My llama value is 2.",
},
.{
.main_file = "075_quiz8.zig",
.output = "Archer's Point--2->Bridge--1->Dogwood Grove--3->Cottage--2->East Pond--1->Fox Pond",
@@ -1078,7 +1102,7 @@ const exercises = [_]Exercise{
.main_file = "082_anonymous_structs3.zig",
.output =
\\"0"(bool):true "1"(bool):false "2"(i32):42 "3"(f32):3.141592
,
, // pay attention to the comma
.hint = "This one is a challenge! But you have everything you need.",
},
.{
@@ -1090,16 +1114,15 @@ const exercises = [_]Exercise{
// direct link: https://github.com/ziglang/zig/issues/6025
.{
.main_file = "084_async.zig",
.output = "foo() A",
.hint = "Read the facts. Use the facts.",
.skip = true,
.skip_hint = "async has not been implemented in the current compiler version.",
.output = "Current time: <timestamp>s since epoch",
.timestamp = true,
// .hint = "Read the facts. Use the facts.",
// .skip = true,
// .skip_hint = "async has not been implemented in the current compiler version.",
},
.{
.main_file = "085_async2.zig",
.output = "Hello async!",
.skip = true,
.skip_hint = "async has not been implemented in the current compiler version.",
.output = "Computing... the answer is: 42",
},
.{
.main_file = "086_async3.zig",
@@ -1145,7 +1168,7 @@ const exercises = [_]Exercise{
\\Ant is alive.
\\Bee visited 17 flowers.
\\Grasshopper hopped 32 meters.
,
, // pay attention to the comma
},
.{
.main_file = "093_hello_c.zig",
@@ -1221,7 +1244,7 @@ const exercises = [_]Exercise{
\\2. Bard (Gold: 11, XP: 17)
\\3. Bard (Gold: 5, XP: 55)
\\4. Warrior (Gold: 7392, XP: 21)
,
, // pay attention to the comma
},
.{
.main_file = "102_testing.zig",
@@ -1247,7 +1270,7 @@ const exercises = [_]Exercise{
\\and
\\despair
\\This little poem has 15 words!
,
, // pay attention to the comma
},
.{
.main_file = "104_threading.zig",
@@ -1261,7 +1284,7 @@ const exercises = [_]Exercise{
\\thread 1: finished.
\\thread 3: finished.
\\Zig is cool!
,
, // pay attention to the comma
},
.{
.main_file = "105_threading2.zig",
@@ -1276,7 +1299,7 @@ const exercises = [_]Exercise{
.output =
\\AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
\\Successfully Read 18 bytes: It's zigling time!
,
, // pay attention to the comma
},
.{
.main_file = "108_labeled_switch.zig",
@@ -1287,7 +1310,7 @@ const exercises = [_]Exercise{
.output =
\\Max difference (old fn): 0.014
\\Max difference (new fn): 0.014
,
, // pay attention to the comma
},
.{ .main_file = "110_quiz9.zig", .output =
\\Toggle pins with XOR on PORTB
@@ -1334,6 +1357,6 @@ const exercises = [_]Exercise{
\\
\\This is the end for now!
\\We hope you had fun and were able to learn a lot, so visit us again when the next exercises are available.
,
, // pay attention to the comma
},
};

86
exercises/084_async.zig
View File

@@ -1,58 +1,48 @@
//
// Six Facts:
// In previous versions of Zig, async/await used special keywords
// like 'suspend', 'resume', and 'async' that operated on stackframes
// directly. Those keywords no longer exist!
//
// 1. The memory space allocated to your program for the
// invocation of a function and all of its data is called a
// "stack frame".
// Zig 0.16 replaced them with a unified I/O interface: std.Io.
// This interface uses a VTable pattern - a struct of function pointers -
// to abstract over different concurrency backends:
//
// 2. The 'return' keyword "pops" the current function
// invocation's frame off of the stack (it is no longer needed)
// and returns control to the place where the function was
// called.
// * Threaded - classic thread-pool based I/O
// * Uring - Linux io_uring
// * Kqueue - BSD/macOS
// * Dispatch - macOS Grand Central Dispatch
//
// fn foo() void {
// return; // Pop the frame and return control
// The Io struct itself is tiny:
//
// const Io = struct {
// userdata: ?*anyopaque, // opaque state of the backend
// vtable: *const VTable, // table of function pointers
// };
//
// Your code receives an Io value and calls methods on it.
// The backend is chosen at initialization time - your code doesn't
// need to know which one it is!
//
// In Zig 0.16, main() receives a std.process.Init struct to opt
// into I/O and concurrency support:
//
// pub fn main(init: std.process.Init) !void {
// const io = init.io;
// // ... use io ...
// }
//
// 3. Like 'return', the 'suspend' keyword returns control to the
// place where the function was called BUT the function
// invocation's frame remains so that it can regain control again
// at a later time. Functions which do this are "async"
// functions.
// Let's start simple. Fix the main function to extract the Io
// interface from init, then use it to get the current time.
//
// fn fooThatSuspends() void {
// suspend {} // return control, but leave the frame alone
// }
//
// 4. To call any function in async context and get a reference
// to its frame for later use, use the 'async' keyword:
//
// var foo_frame = async fooThatSuspends();
//
// 5. If you call an async function without the 'async' keyword,
// the function FROM WHICH you called the async function itself
// becomes async! In this example, the bar() function is now
// async because it calls fooThatSuspends(), which is async.
//
// fn bar() void {
// fooThatSuspends();
// }
//
// 6. The main() function cannot be async!
//
// Given facts 3 and 4, how do we fix this program (broken by facts
// 5 and 6)?
//
const print = @import("std").debug.print;
const std = @import("std");
pub fn main() void {
// Additional Hint: you can assign things to '_' when you
// don't intend to do anything with them.
foo();
}
pub fn main(init: std.process.Init) !void {
const io = init.???;
fn foo() void {
print("foo() A\n", .{});
suspend {}
print("foo() B\n", .{});
// Get the current wall-clock time using the Io interface.
// Hint: Timestamp.now() takes an Io and a Clock type (.real = wall clock).
const timestamp = std.Io.Timestamp.now(io, .real);
// Print the timestamp in seconds since the Unix epoch.
std.debug.print("Current time: {}s since epoch\n", .{timestamp.toSeconds()});
}

56
exercises/085_async2.zig
View File

@@ -1,28 +1,48 @@
//
// So, 'suspend' returns control to the place from which it was
// called (the "call site"). How do we give control back to the
// suspended function?
// Now that we know how to get an Io value, let's use it for
// asynchronous execution!
//
// For that, we have a new keyword called 'resume' which takes an
// async function invocation's frame and returns control to it.
// io.async() launches a function and returns a Future. The result
// won't necessarily be available until you call .await() on it:
//
// fn fooThatSuspends() void {
// suspend {}
// }
// var future = io.async(someFunction, .{ arg1, arg2 });
// // ... do other work here ...
// const result = future.await(io);
//
// var foo_frame = async fooThatSuspends();
// resume foo_frame;
// The function *may* run immediately or on another thread -
// your code doesn't need to care! That's the beauty of the
// Io abstraction. (In the Threaded backend, if no thread is
// available, the function runs synchronously right away and
// .await() just returns the already-computed result.)
//
// See if you can make this program print "Hello async!".
// io.async() returns a Future(T) where T is the return type
// of the function you passed in. Future has two key methods:
//
const print = @import("std").debug.print;
// .await(io) - block until the result is ready, return it
// .cancel(io) - request cancellation, then return the result
//
// Fix this program so that computeAnswer runs asynchronously
// and its result is properly awaited.
//
const std = @import("std");
pub fn main() void {
var foo_frame = async foo();
pub fn main(init: std.process.Init) !void {
const io = init.io;
// Launch computeAnswer asynchronously.
// io.async() takes a function and a tuple of its arguments.
var future = io.async(computeAnswer, .{ 6, 7 });
// Meanwhile, print something to show we're not blocked.
std.debug.print("Computing... ", .{});
// Now collect the result. What method on Future gives us
// the value, blocking if it isn't ready yet?
const answer = future.???(io);
std.debug.print("The answer is: {}\n", .{answer});
}
fn foo() void {
print("Hello ", .{});
suspend {}
print("async!\n", .{});
fn computeAnswer(a: u32, b: u32) u32 {
return a * b;
}