1 files changed, 49 insertions, 0 deletions
diff --git a/exercises/087_async3.zig b/exercises/087_async3.zig
new file mode 100644
index 0000000..d10052c
--- /dev/null
+++ b/exercises/087_async3.zig
@@ -0,0 +1,49 @@
+//
+// The real power of async shows when you launch MULTIPLE tasks!
+//
+// With io.async(), you can start several operations, then await
+// them all. The Io backend may run them concurrently:
+//
+//     var f1 = io.async(taskA, .{});
+//     defer _ = f1.cancel(io);
+//     var f2 = io.async(taskB, .{});
+//     defer _ = f2.cancel(io);
+//     const a = f1.await(io);
+//     const b = f2.await(io);
+//
+// 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.
+//
+const std = @import("std");
+const print = std.debug.print;
+
+pub fn main(init: std.process.Init) !void {
+    const io = init.io;
+
+    // Launch both tasks asynchronously.
+    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.await(io);
+
+    print("{} + {} = {}\n", .{ 1, 2, sum });
+    print("{} * {} = {}\n", .{ 6, 7, product });
+    print("Total: {}\n", .{sum + product});
+}
+
+fn slowAdd(a: u32, b: u32) u32 {
+    return a + b;
+}
+
+fn slowMul(a: u32, b: u32) u32 {
+    return a * b;
+}