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-rw-r--r--build.zig6
-rw-r--r--exercises/085_async.zig9
-rw-r--r--exercises/086_async2.zig32
-rw-r--r--exercises/087_async3.zig23
-rw-r--r--exercises/088_async4.zig4
-rw-r--r--exercises/089_async5.zig12
-rw-r--r--exercises/090_async6.zig7
-rw-r--r--exercises/093_async9.zig42
-rw-r--r--exercises/094_async10.zig11
-rw-r--r--exercises/095_quiz_async.zig60
-rw-r--r--patches/patches/085_async.patch6
-rw-r--r--patches/patches/086_async2.patch10
-rw-r--r--patches/patches/087_async3.patch19
-rw-r--r--patches/patches/088_async4.patch6
-rw-r--r--patches/patches/089_async5.patch8
-rw-r--r--patches/patches/090_async6.patch8
-rw-r--r--patches/patches/093_async9.patch14
-rw-r--r--patches/patches/094_async10.patch8
-rw-r--r--patches/patches/095_quiz_async.patch52
19 files changed, 183 insertions, 154 deletions
diff --git a/build.zig b/build.zig
index 3cddb61..dcafe14 100644
--- a/build.zig
+++ b/build.zig
@@ -1180,9 +1180,9 @@ const exercises = [_]Exercise{
.{
.main_file = "093_async9.zig",
.output =
- \\Main thread continues...
- \\Computing on a separate thread!
- \\Main thread done waiting.
+ \\Computing concurrently!
+ \\Main continues...
+ \\Main done waiting.
\\Result: 123
, // pay attention to the comma
},
diff --git a/exercises/085_async.zig b/exercises/085_async.zig
index 48bda2b..1d885a5 100644
--- a/exercises/085_async.zig
+++ b/exercises/085_async.zig
@@ -7,10 +7,11 @@
// This interface uses a VTable pattern - a struct of function pointers -
// to abstract over different concurrency backends:
//
-// * Threaded - classic thread-pool based I/O
-// * Uring - Linux io_uring
-// * Kqueue - BSD/macOS
-// * Dispatch - macOS Grand Central Dispatch
+// * Threaded - thread-pool based I/O
+// * Evented - chooses the best event-loop backend for your OS:
+// * Uring on Linux (io_uring)
+// * Kqueue on BSD/macOS
+// * Dispatch on macOS (Grand Central Dispatch)
//
// The Io struct itself is tiny:
//
diff --git a/exercises/086_async2.zig b/exercises/086_async2.zig
index 1f1c4c8..cf376e2 100644
--- a/exercises/086_async2.zig
+++ b/exercises/086_async2.zig
@@ -6,41 +6,47 @@
// won't necessarily be available until you call .await() on it:
//
// var future = io.async(someFunction, .{ arg1, arg2 });
-// // ... do other work here ...
// const result = future.await(io);
//
// 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.)
+// Io abstraction.
//
-// io.async() returns a Future(T) where T is the return type
-// of the function you passed in. Future has two key methods:
+// IMPORTANT: Every Future MUST be either .await()ed or .cancel()ed.
+// Failing to do so leaks resources! A safe pattern is:
//
-// .await(io) - block until the result is ready, return it
-// .cancel(io) - request cancellation, then return the result
+// var future = io.async(myFn, .{});
+// defer _ = future.cancel(io); // safety net
+// // ... later, if we want the result:
+// const result = future.await(io);
+// // (await after cancel is fine — it just returns the result)
+//
+// Both .await() and .cancel() block until the task finishes and
+// return the result. The difference is that .cancel() also
+// requests the task to stop at its next cancellation point.
+// Calling either one more than once is safe — subsequent calls
+// just return a copy of the result.
//
// Fix this program so that computeAnswer runs asynchronously
// and its result is properly awaited.
//
const std = @import("std");
+const print = std.debug.print;
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 });
+ defer _ = future.cancel(io); // always clean up!
- // Meanwhile, print something to show we're not blocked.
- std.debug.print("Computing... ", .{});
+ print("Computing... ", .{});
// Now collect the result. What method on Future gives us
- // the value, blocking if it isn't ready yet?
+ // the value, blocking until it's ready?
const answer = future.???(io);
- std.debug.print("The answer is: {}\n", .{answer});
+ print("The answer is: {}\n", .{answer});
}
fn computeAnswer(a: u32, b: u32) u32 {
diff --git a/exercises/087_async3.zig b/exercises/087_async3.zig
index 07221e9..d10052c 100644
--- a/exercises/087_async3.zig
+++ b/exercises/087_async3.zig
@@ -5,20 +5,17 @@
// them all. The Io backend may run them concurrently:
//
// var f1 = io.async(taskA, .{});
+// defer _ = f1.cancel(io);
// var f2 = io.async(taskB, .{});
-//
-// // Both tasks may be running now!
+// defer _ = f2.cancel(io);
// const a = f1.await(io);
// const b = f2.await(io);
//
-// There's also io.concurrent() which provides a STRONGER guarantee:
-// it ensures the function gets its own unit of concurrency (e.g. a
-// real OS thread). But it can fail with error.ConcurrencyUnavailable
-// if resources are exhausted.
-//
-// io.async() is more portable: if no thread is available, it simply
-// runs the function synchronously. This makes it the right default
-// for most code.
+// Notice the defer pattern: each async call is immediately
+// followed by a defer cancel. This ensures cleanup even if
+// we return early or hit an error before reaching await.
+// Since await/cancel are idempotent, the defer is harmless
+// if we've already awaited.
//
// Fix this program to launch both tasks and collect their results.
//
@@ -29,12 +26,14 @@ pub fn main(init: std.process.Init) !void {
const io = init.io;
// Launch both tasks asynchronously.
- var future_a = io.async(slowAdd, .{ 10, 20 });
+ var future_a = io.async(slowAdd, .{ 1, 2 });
+ defer _ = future_a.cancel(io);
var future_b = ???(slowMul, .{ 6, 7 });
+ defer _ = future_b.cancel(io);
// Await both results.
const sum = future_a.await(io);
- const product = future_b.???(io);
+ const product = future_b.await(io);
print("{} + {} = {}\n", .{ 1, 2, sum });
print("{} * {} = {}\n", .{ 6, 7, product });
diff --git a/exercises/088_async4.zig b/exercises/088_async4.zig
index 50829fc..8298ca1 100644
--- a/exercises/088_async4.zig
+++ b/exercises/088_async4.zig
@@ -14,7 +14,7 @@
// * Once you call group.async(), you MUST eventually call
// group.await() or group.cancel() to release resources.
// * group.cancel() requests cancellation on ALL members,
-// then waits for them to finish.
+// then blocks until they all finish.
//
// Unlike Future, Group tasks don't return values to the caller.
// They're ideal for parallel work that communicates through
@@ -38,7 +38,7 @@ pub fn main(init: std.process.Init) !void {
// Wait for all tasks to finish.
// What Group method blocks until all tasks complete?
- try group.???
+ try group.???(io);
print("All tasks finished!\n", .{});
}
diff --git a/exercises/089_async5.zig b/exercises/089_async5.zig
index 4fb8d76..0c00c1f 100644
--- a/exercises/089_async5.zig
+++ b/exercises/089_async5.zig
@@ -5,7 +5,7 @@
// Every Future has a .cancel() method that:
// 1. Requests the task to stop (via error.Canceled at the
// next "cancellation point")
-// 2. Waits for the task to actually finish
+// 2. BLOCKS until the task actually finishes
// 3. Returns whatever result the task produced
//
// A "cancellation point" is any Io function that can return
@@ -13,7 +13,7 @@
//
// fn myTask(io: std.Io) u32 {
// io.sleep(...) catch |err| switch (err) {
-// error.Canceled => return 0, // handle gracefully
+// error.Canceled => return 0, // error handle
// };
// return 42;
// }
@@ -21,6 +21,11 @@
// This is fundamentally different from killing a thread -
// the task gets a chance to clean up and return a value!
//
+// Remember: both .await() and .cancel() block and return the
+// result. The only difference is that .cancel() also sends
+// the cancellation request. And both are idempotent — calling
+// either one again just returns the same result.
+//
// Fix this program: the slow task would take 10 seconds,
// but we cancel it after 1 second. The task should detect
// the cancellation and return early.
@@ -32,6 +37,7 @@ pub fn main(init: std.process.Init) !void {
const io = init.io;
var future = io.async(slowTask, .{io});
+ defer _ = future.cancel(io); // safety net
// Wait 1 second, then cancel instead of waiting the full 10.
io.sleep(std.Io.Duration.fromSeconds(1), .awake) catch {};
@@ -40,7 +46,7 @@ pub fn main(init: std.process.Init) !void {
// We don't want to wait 10 seconds!
// Which Future method requests cancellation AND returns the result?
- const result = ???;
+ const result = future.???(io);
print("Task returned: {}\n", .{result});
}
diff --git a/exercises/090_async6.zig b/exercises/090_async6.zig
index eab03c9..16fb75f 100644
--- a/exercises/090_async6.zig
+++ b/exercises/090_async6.zig
@@ -23,6 +23,11 @@
// }
// sel.cancelDiscard(); // cancel remaining, discard results
//
+// As with all async primitives: tasks spawned in a Select MUST
+// be cleaned up. Use sel.cancel() to get remaining results one
+// by one (for resource cleanup), or sel.cancelDiscard() if you
+// don't need them.
+//
// The buffer must be large enough for all tasks that might
// complete before you call cancelDiscard().
//
@@ -47,7 +52,7 @@ pub fn main(init: std.process.Init) !void {
// Wait for the first finisher.
// What Select method returns the first completed result?
- const winner = ???;
+ const winner = try sel.???();
switch (winner) {
.hare => |msg| print("Hare: {s}\n", .{msg}),
diff --git a/exercises/093_async9.zig b/exercises/093_async9.zig
index ad30dcf..4a41544 100644
--- a/exercises/093_async9.zig
+++ b/exercises/093_async9.zig
@@ -5,22 +5,29 @@
// The difference:
//
// io.async():
-// * The function MAY run on another thread, or it may run
-// immediately on the current thread (synchronously).
-// * Never fails — if no thread is available, it just runs
-// the function right away.
+// * The function MAY run on a separate unit of concurrency,
+// or it may run immediately on the caller (synchronously).
+// * Never fails — if no concurrency is available, it just
+// runs the function right away.
// * More portable, works with all Io backends.
//
// io.concurrent():
-// * GUARANTEES a separate unit of concurrency (a real thread
-// in the Threaded backend).
+// * GUARANTEES a separate unit of concurrency.
// * Can fail with error.ConcurrencyUnavailable if resources
// are exhausted or the backend doesn't support it.
-// * Use when you NEED true parallelism.
+// * Use when you NEED the task to run independently of the
+// caller.
+//
+// What is a "unit of concurrency"? That depends on the backend!
+// The Threaded backend uses OS threads. But the Evented backends
+// (Uring, Kqueue, Dispatch) use M:N green threads / fibers,
+// which can provide concurrency even on a SINGLE OS thread.
+// Your code doesn't need to know the difference.
//
// Because concurrent() can fail, you must handle the error:
//
// var future = try io.concurrent(myFn, .{args});
+// defer _ = future.cancel(io);
// const result = future.await(io);
//
// Notice the 'try' — that's the key difference in usage!
@@ -33,25 +40,30 @@ const print = std.debug.print;
pub fn main(init: std.process.Init) !void {
const io = init.io;
- // Launch with a guaranteed separate thread.
- // Which Io method guarantees true concurrency?
+ // Launch with a guaranteed separate unit of concurrency.
+ // Which Io method guarantees this?
// (Hint: unlike io.async, this one can fail!)
var future = try io.???(compute, .{io});
+ defer _ = future.cancel(io);
- print("Main thread continues...\n", .{});
-
- // Wait 100 millisecond so the output order is deterministic.
+ // Note: All breaks in this excercise (using sleep)
+ // are only necessary for a deterministic result.
io.sleep(std.Io.Duration.fromMilliseconds(100), .awake) catch {};
- print("Main thread done waiting.\n", .{});
+ print("Main continues...\n", .{});
+
+ // Wait 1 second for the output order.
+ io.sleep(std.Io.Duration.fromMilliseconds(200), .awake) catch {};
+
+ print("Main done waiting.\n", .{});
const result = future.await(io);
print("Result: {}\n", .{result});
}
fn compute(io: std.Io) u32 {
- print("Computing on a separate thread!\n", .{});
+ print("Computing concurrently!\n", .{});
// Simulate some work.
- io.sleep(std.Io.Duration.fromMilliseconds(200), .awake) catch return 0;
+ io.sleep(std.Io.Duration.fromMilliseconds(400), .awake) catch return 0;
return 123;
}
diff --git a/exercises/094_async10.zig b/exercises/094_async10.zig
index 6ed229d..c561d37 100644
--- a/exercises/094_async10.zig
+++ b/exercises/094_async10.zig
@@ -1,5 +1,5 @@
//
-// In exercise 088, we learned that cancellation happens at
+// In exercise 089, we learned that cancellation happens at
// "cancellation points" — any Io function that can return
// error.Canceled.
//
@@ -11,7 +11,7 @@
//
// const old = io.swapCancelProtection(.blocked);
// defer _ = io.swapCancelProtection(old);
-//
+
// // In this block, NO Io function will return error.Canceled.
// // The cancel request is held until protection is restored.
//
@@ -36,9 +36,10 @@ pub fn main(init: std.process.Init) !void {
const io = init.io;
var future = io.async(importantTask, .{io});
+ defer _ = future.cancel(io);
// Give the task time to start and enter its critical section.
- io.sleep(std.Io.Duration.fromMilliseconds(300), .awake) catch {};
+ io.sleep(std.Io.Duration.fromMilliseconds(200), .awake) catch {};
// Cancel while the task is in its protected section.
const result = future.cancel(io);
@@ -50,12 +51,12 @@ fn importantTask(io: std.Io) []const u8 {
// Protect this section from cancellation.
// What method swaps the cancel protection state?
- const old = io.???(. blocked);
+ const old = io.???(.blocked);
defer _ = io.???(old);
// This sleep will NOT return error.Canceled even though
// we get canceled during it — protection is active!
- io.sleep(std.Io.Duration.fromMilliseconds(600), .awake) catch |err| switch (err) {
+ io.sleep(std.Io.Duration.fromMilliseconds(300), .awake) catch |err| switch (err) {
error.Canceled => {
// This should never happen while protected!
return "ERROR: canceled during critical section!";
diff --git a/exercises/095_quiz_async.zig b/exercises/095_quiz_async.zig
index fb78e7b..b116fc9 100644
--- a/exercises/095_quiz_async.zig
+++ b/exercises/095_quiz_async.zig
@@ -16,16 +16,17 @@
// by a grasshopper) and left several bugs. Can you fix them?
//
// Here's what the program should do:
-// 1. Three sensor tasks run concurrently, each sending
-// exactly 3 readings through a Queue
-// 2. A collector task receives readings, protected by a Mutex
+// 1. Three sensor tasks send exactly 3 readings each through
+// a Queue
+// 2. A collector task receives readings concurrently,
+// protected by a Mutex
// 3. After all sensors finish, the queue is closed
// 4. The final report is written in a cancel-protected section
//
// *************************************************************
// * A NOTE ABOUT THIS EXERCISE *
// * *
-// * This quiz uses concepts from exercises 084-093. *
+// * This quiz uses concepts from exercises 085-094. *
// * There are 6 bugs to fix — look for the ???s! *
// * *
// *************************************************************
@@ -50,8 +51,8 @@ const GardenWeather = struct {
fn addReading(self: *GardenWeather, io: std.Io, reading: Reading) void {
// Bug 1: The collector needs to lock before modifying
// shared state. What Mutex method acquires the lock?
- self.mutex.lock(io) catch return;
self.mutex.???(io) catch return;
+ defer self.mutex.unlock(io);
switch (reading.sensor_type) {
.thermometer => self.temperature = reading.value,
@@ -70,39 +71,40 @@ pub fn main(init: std.process.Init) !void {
var reading_buf: [8]Reading = undefined;
var queue: std.Io.Queue(Reading) = .init(&reading_buf);
- // Sensor group: runs all three sensors to completion.
- var sensors: std.Io.Group = .init;
-
- // Start three sensor tasks. They need GUARANTEED concurrency
- // since they each simulate real-time measurement.
+ // The collector must run concurrently so it can process
+ // readings while the sensors are still sending.
+ // Start it FIRST to ensure its concurrency unit is reserved.
//
- // Bug 2: io.async doesn't guarantee a separate thread.
- // Which Io method guarantees true concurrency?
- // (Don't forget: it can fail, so you need 'try'!)
- try sensors.???(io, sensor, .{ io, &queue, .thermometer, 20 });
- try sensors.???(io, sensor, .{ io, &queue, .hygrometer, 60 });
- try sensors.???(io, sensor, .{ io, &queue, .anemometer, 10 });
+ // Bug 2: The collector needs guaranteed concurrency.
+ // What method ensures a separate unit of concurrency?
+ // (Don't forget: it can fail!)
+ var collector_future = try io.???(collector, .{ io, &queue, &weather });
+ defer _ = collector_future.cancel(io);
+
+ // Sensor group: the sensors can use async — they just need
+ // to run, and async is more portable.
+ var sensors: std.Io.Group = .init;
- // Collector group: processes readings from the queue.
- var collectors: std.Io.Group = .init;
- collectors.async(io, collector, .{ io, &queue, &weather });
+ sensors.async(io, sensor, .{ io, &queue, .thermometer, 20 });
+ sensors.async(io, sensor, .{ io, &queue, .hygrometer, 60 });
+ sensors.async(io, sensor, .{ io, &queue, .anemometer, 10 });
// Bug 3: Wait for ALL sensors to finish sending their readings.
// What Group method blocks until all tasks complete?
- try sensors.await(io);
- // try sensors.???(io);
+ try sensors.???(io);
// All sensors done — close the queue so the collector knows
// there's no more data coming.
queue.close(io);
- // Wait for the collector to drain the queue.
- try collectors.await(io);
+ // Wait for the collector to drain the remaining queue.
+ _ = collector_future.await(io);
+ // _ = collector_future.???(io);
// Now write the garden report. This is critical — it must
// NOT be interrupted, even if something tries to cancel us!
//
- // Bug 4: Protect this section from cancellation.
+ // Bug 5: Protect this section from cancellation.
// What Io method swaps the cancel protection state?
const old_protection = io.???(.blocked);
defer _ = io.???(old_protection);
@@ -125,7 +127,7 @@ fn sensor(
.value = base_value + @as(i32, @intCast(i)),
};
- // Bug 5: Send the reading into the queue.
+ // Bug 6: Send the reading into the queue.
// What Queue method sends a single element?
queue.???(io, reading) catch return;
}
@@ -163,8 +165,7 @@ fn printGardenReport(weather: *GardenWeather) void {
//
// This quiz covered the main async I/O primitives:
// io.async() - launch a task (may run inline)
-// io.concurrent() - launch with guaranteed parallelism
-// Group.concurrent() - concurrent tasks in a group
+// io.concurrent() - guaranteed unit of concurrency
// Future.await/cancel - collect or cancel a single task
// Group.async/await/cancel - manage fire-and-forget tasks
// Select.async/await - race tasks, act on first completion
@@ -180,7 +181,8 @@ fn printGardenReport(weather: *GardenWeather) void {
// Batch - submit multiple I/O operations at once
//
// The key insight: all of these work through the Io VTable,
-// so your code is portable across backends (Threaded, Uring,
-// Kqueue, Dispatch) without any changes!
+// so your code is portable across backends — whether Threaded
+// (OS thread pool), or Evented (M:N green threads / fibers
+// that can provide concurrency even on a single OS thread).
//
// Doctor Zoraptera approves.
diff --git a/patches/patches/085_async.patch b/patches/patches/085_async.patch
index ca8b102..108eae1 100644
--- a/patches/patches/085_async.patch
+++ b/patches/patches/085_async.patch
@@ -1,6 +1,6 @@
---- exercises/085_async.zig 2026-04-01 20:40:08.904999609 +0200
-+++ answers/085_async.zig 2026-04-01 20:40:05.641933231 +0200
-@@ -37,7 +37,7 @@
+--- exercises/085_async.zig 2026-04-04 16:01:01.509555724 +0200
++++ answers/085_async.zig 2026-04-04 16:00:58.541495688 +0200
+@@ -38,7 +38,7 @@
const std = @import("std");
pub fn main(init: std.process.Init) !void {
diff --git a/patches/patches/086_async2.patch b/patches/patches/086_async2.patch
index 9a672a6..1738089 100644
--- a/patches/patches/086_async2.patch
+++ b/patches/patches/086_async2.patch
@@ -1,11 +1,11 @@
---- exercises/086_async2.zig 2026-04-03 19:42:15.274532915 +0200
-+++ answers/086_async2.zig 2026-04-03 21:30:18.180019206 +0200
-@@ -38,7 +38,7 @@
+--- exercises/086_async2.zig 2026-04-05 12:41:11.350626443 +0200
++++ answers/086_async2.zig 2026-04-05 12:42:00.879791167 +0200
+@@ -44,7 +44,7 @@
// Now collect the result. What method on Future gives us
- // the value, blocking if it isn't ready yet?
+ // the value, blocking until it's ready?
- const answer = future.???(io);
+ const answer = future.await(io);
- std.debug.print("The answer is: {}\n", .{answer});
+ print("The answer is: {}\n", .{answer});
}
diff --git a/patches/patches/087_async3.patch b/patches/patches/087_async3.patch
index 8365e7a..91ba9af 100644
--- a/patches/patches/087_async3.patch
+++ b/patches/patches/087_async3.patch
@@ -1,18 +1,11 @@
---- exercises/087_async3.zig 2026-04-01 22:51:05.540094851 +0200
-+++ answers/087_async3.zig 2026-04-01 22:50:44.579669189 +0200
-@@ -29,12 +29,12 @@
- const io = init.io;
-
+--- exercises/087_async3.zig 2026-04-05 16:12:48.317265515 +0200
++++ answers/087_async3.zig 2026-04-05 16:12:52.269343030 +0200
+@@ -28,7 +28,7 @@
// Launch both tasks asynchronously.
-- var future_a = io.async(slowAdd, .{ 10, 20 });
+ var future_a = io.async(slowAdd, .{ 1, 2 });
+ defer _ = future_a.cancel(io);
- var future_b = ???(slowMul, .{ 6, 7 });
-+ var future_a = io.async(slowAdd, .{ 1, 2 });
+ var future_b = io.async(slowMul, .{ 6, 7 });
+ defer _ = future_b.cancel(io);
// Await both results.
- const sum = future_a.await(io);
-- const product = future_b.???(io);
-+ const product = future_b.await(io);
-
- print("{} + {} = {}\n", .{ 1, 2, sum });
- print("{} * {} = {}\n", .{ 6, 7, product });
diff --git a/patches/patches/088_async4.patch b/patches/patches/088_async4.patch
index 1faf30e..6cf549f 100644
--- a/patches/patches/088_async4.patch
+++ b/patches/patches/088_async4.patch
@@ -1,10 +1,10 @@
---- exercises/088_async4.zig 2026-04-01 23:17:31.066443941 +0200
-+++ answers/088_async4.zig 2026-04-01 23:17:39.251612131 +0200
+--- exercises/088_async4.zig 2026-04-06 12:22:06.643385622 +0200
++++ answers/088_async4.zig 2026-04-06 12:22:11.820491035 +0200
@@ -38,7 +38,7 @@
// Wait for all tasks to finish.
// What Group method blocks until all tasks complete?
-- try group.???
+- try group.???(io);
+ try group.await(io);
print("All tasks finished!\n", .{});
diff --git a/patches/patches/089_async5.patch b/patches/patches/089_async5.patch
index d2baa96..3cea4e9 100644
--- a/patches/patches/089_async5.patch
+++ b/patches/patches/089_async5.patch
@@ -1,10 +1,10 @@
---- exercises/089_async5.zig 2026-04-01 23:40:40.505855238 +0200
-+++ answers/089_async5.zig 2026-04-01 23:40:10.176236971 +0200
-@@ -40,7 +40,7 @@
+--- exercises/089_async5.zig 2026-04-06 14:38:54.443726849 +0200
++++ answers/089_async5.zig 2026-04-06 14:38:39.945438309 +0200
+@@ -46,7 +46,7 @@
// We don't want to wait 10 seconds!
// Which Future method requests cancellation AND returns the result?
-- const result = ???;
+- const result = future.???(io);
+ const result = future.cancel(io);
print("Task returned: {}\n", .{result});
diff --git a/patches/patches/090_async6.patch b/patches/patches/090_async6.patch
index 5ac777b..6289708 100644
--- a/patches/patches/090_async6.patch
+++ b/patches/patches/090_async6.patch
@@ -1,10 +1,10 @@
---- exercises/090_async6.zig 2026-04-02 10:25:34.016616118 +0200
-+++ answers/090_async6.zig 2026-04-02 10:27:48.827144051 +0200
-@@ -47,7 +47,7 @@
+--- exercises/090_async6.zig 2026-04-06 18:49:37.232023422 +0200
++++ answers/090_async6.zig 2026-04-06 18:49:22.189720687 +0200
+@@ -52,7 +52,7 @@
// Wait for the first finisher.
// What Select method returns the first completed result?
-- const winner = ???;
+- const winner = try sel.???();
+ const winner = try sel.await();
switch (winner) {
diff --git a/patches/patches/093_async9.patch b/patches/patches/093_async9.patch
index f759921..ebdfce2 100644
--- a/patches/patches/093_async9.patch
+++ b/patches/patches/093_async9.patch
@@ -1,11 +1,11 @@
---- exercises/093_async9.zig 2026-04-03 13:44:50.526780809 +0200
-+++ answers/093_async9.zig 2026-04-03 13:44:54.957870294 +0200
-@@ -36,7 +36,7 @@
- // Launch with a guaranteed separate thread.
- // Which Io method guarantees true concurrency?
+--- exercises/093_async9.zig 2026-04-06 19:26:11.388025362 +0200
++++ answers/093_async9.zig 2026-04-06 19:18:36.242931688 +0200
+@@ -43,7 +43,7 @@
+ // Launch with a guaranteed separate unit of concurrency.
+ // Which Io method guarantees this?
// (Hint: unlike io.async, this one can fail!)
- var future = try io.???(compute, .{io});
+ var future = try io.concurrent(compute, .{io});
+ defer _ = future.cancel(io);
- print("Main thread continues...\n", .{});
-
+ // Note: All breaks in this excercise (using sleep)
diff --git a/patches/patches/094_async10.patch b/patches/patches/094_async10.patch
index ae0d26d..e721485 100644
--- a/patches/patches/094_async10.patch
+++ b/patches/patches/094_async10.patch
@@ -1,10 +1,10 @@
---- exercises/094_async10.zig 2026-04-03 14:25:16.600025924 +0200
-+++ answers/094_async10.zig 2026-04-03 14:24:56.192615893 +0200
-@@ -50,8 +50,8 @@
+--- exercises/094_async10.zig 2026-04-06 19:36:59.873966580 +0200
++++ answers/094_async10.zig 2026-04-06 19:37:12.416216872 +0200
+@@ -51,8 +51,8 @@
// Protect this section from cancellation.
// What method swaps the cancel protection state?
-- const old = io.???(. blocked);
+- const old = io.???(.blocked);
- defer _ = io.???(old);
+ const old = io.swapCancelProtection(.blocked);
+ defer _ = io.swapCancelProtection(old);
diff --git a/patches/patches/095_quiz_async.patch b/patches/patches/095_quiz_async.patch
index dbaae07..e3d2a79 100644
--- a/patches/patches/095_quiz_async.patch
+++ b/patches/patches/095_quiz_async.patch
@@ -1,38 +1,42 @@
---- exercises/095_quiz_async.zig 2026-04-03 18:04:53.577391455 +0200
-+++ answers/095_quiz_async.zig 2026-04-03 18:05:42.570392172 +0200
+--- exercises/095_quiz_async.zig 2026-04-06 19:55:17.111817364 +0200
++++ answers/095_quiz_async.zig 2026-04-06 19:56:16.063974543 +0200
@@ -51,7 +51,7 @@
+ fn addReading(self: *GardenWeather, io: std.Io, reading: Reading) void {
// Bug 1: The collector needs to lock before modifying
// shared state. What Mutex method acquires the lock?
- self.mutex.lock(io) catch return;
- self.mutex.???(io) catch return;
-+ defer self.mutex.unlock(io);
++ self.mutex.lock(io) catch return;
+ defer self.mutex.unlock(io);
switch (reading.sensor_type) {
- .thermometer => self.temperature = reading.value,
-@@ -79,9 +79,9 @@
- // Bug 2: io.async doesn't guarantee a separate thread.
- // Which Io method guarantees true concurrency?
- // (Don't forget: it can fail, so you need 'try'!)
-- try sensors.???(io, sensor, .{ io, &queue, .thermometer, 20 });
-- try sensors.???(io, sensor, .{ io, &queue, .hygrometer, 60 });
-- try sensors.???(io, sensor, .{ io, &queue, .anemometer, 10 });
-+ try sensors.concurrent(io, sensor, .{ io, &queue, .thermometer, 20 });
-+ try sensors.concurrent(io, sensor, .{ io, &queue, .hygrometer, 60 });
-+ try sensors.concurrent(io, sensor, .{ io, &queue, .anemometer, 10 });
+@@ -78,7 +78,7 @@
+ // Bug 2: The collector needs guaranteed concurrency.
+ // What method ensures a separate unit of concurrency?
+ // (Don't forget: it can fail!)
+- var collector_future = try io.???(collector, .{ io, &queue, &weather });
++ var collector_future = try io.concurrent(collector, .{ io, &queue, &weather });
+ defer _ = collector_future.cancel(io);
+
+ // Sensor group: the sensors can use async — they just need
+@@ -91,7 +91,7 @@
- // Collector group: processes readings from the queue.
- var collectors: std.Io.Group = .init;
-@@ -90,7 +90,6 @@
// Bug 3: Wait for ALL sensors to finish sending their readings.
// What Group method blocks until all tasks complete?
- try sensors.await(io);
-- // try sensors.???(io);
+- try sensors.???(io);
++ try sensors.await(io);
// All sensors done — close the queue so the collector knows
// there's no more data coming.
-@@ -104,8 +103,8 @@
+@@ -99,15 +99,14 @@
+
+ // Wait for the collector to drain the remaining queue.
+ _ = collector_future.await(io);
+- // _ = collector_future.???(io);
+
+ // Now write the garden report. This is critical — it must
+ // NOT be interrupted, even if something tries to cancel us!
//
- // Bug 4: Protect this section from cancellation.
+ // Bug 5: Protect this section from cancellation.
// What Io method swaps the cancel protection state?
- const old_protection = io.???(.blocked);
- defer _ = io.???(old_protection);
@@ -41,9 +45,9 @@
printGardenReport(&weather);
}
-@@ -127,7 +126,7 @@
+@@ -129,7 +128,7 @@
- // Bug 5: Send the reading into the queue.
+ // Bug 6: Send the reading into the queue.
// What Queue method sends a single element?
- queue.???(io, reading) catch return;
+ queue.putOne(io, reading) catch return;
generated by cgit v1.2.3 (git 2.51.0) at 2026-06-30 08:32:59 +0000