my ziglings
improvements for async-io
Chris Boesch
(Apr 6, 2026, 7:38 PM +0200)
55a4841b
09bae6a7
+10
-9
+6
-5
exercises/094_async10.zig
+6
-5
exercises/094_async10.zig
···
1
1
//
2
-
// In exercise 088, we learned that cancellation happens at
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+
// In exercise 089, we learned that cancellation happens at
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3
// "cancellation points" — any Io function that can return
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// error.Canceled.
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5
//
···
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//
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// const old = io.swapCancelProtection(.blocked);
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// defer _ = io.swapCancelProtection(old);
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-
//
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+
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// // In this block, NO Io function will return error.Canceled.
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// // The cancel request is held until protection is restored.
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//
···
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const io = init.io;
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var future = io.async(importantTask, .{io});
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+
defer _ = future.cancel(io);
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// Give the task time to start and enter its critical section.
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-
io.sleep(std.Io.Duration.fromMilliseconds(300), .awake) catch {};
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+
io.sleep(std.Io.Duration.fromMilliseconds(200), .awake) catch {};
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// Cancel while the task is in its protected section.
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const result = future.cancel(io);
···
50
51
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// Protect this section from cancellation.
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// What method swaps the cancel protection state?
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-
const old = io.???(. blocked);
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+
const old = io.???(.blocked);
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defer _ = io.???(old);
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// This sleep will NOT return error.Canceled even though
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// we get canceled during it — protection is active!
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-
io.sleep(std.Io.Duration.fromMilliseconds(600), .awake) catch |err| switch (err) {
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+
io.sleep(std.Io.Duration.fromMilliseconds(300), .awake) catch |err| switch (err) {
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error.Canceled => {
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// This should never happen while protected!
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return "ERROR: canceled during critical section!";
+4
-4
patches/patches/094_async10.patch
+4
-4
patches/patches/094_async10.patch
···
1
-
--- exercises/094_async10.zig 2026-04-03 14:25:16.600025924 +0200
2
-
+++ answers/094_async10.zig 2026-04-03 14:24:56.192615893 +0200
3
-
@@ -50,8 +50,8 @@
1
+
--- exercises/094_async10.zig 2026-04-06 19:36:59.873966580 +0200
2
+
+++ answers/094_async10.zig 2026-04-06 19:37:12.416216872 +0200
3
+
@@ -51,8 +51,8 @@
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4
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5
// Protect this section from cancellation.
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6
// What method swaps the cancel protection state?
7
-
- const old = io.???(. blocked);
7
+
- const old = io.???(.blocked);
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8
- defer _ = io.???(old);
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9
+ const old = io.swapCancelProtection(.blocked);
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10
+ defer _ = io.swapCancelProtection(old);