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// RUN: %target-run-simple-swift( -Xfrontend -disable-availability-checking %import-libdispatch -parse-as-library) | %FileCheck %s --dump-input=always
// REQUIRES: executable_test
// REQUIRES: concurrency
// REQUIRES: libdispatch
// rdar://113915243 - flaky test on watchos
// UNSUPPORTED: OS=watchos
// REQUIRES: concurrency_runtime
import Dispatch
func completeSlowly(n: Int) async -> Int {
try? await Task.sleep(for: .milliseconds(n * 300))
return n
}
/// Tasks complete AFTER they are next() polled.
func test_sum_nextOnPending() async {
let numbers = [1, 2, 3]
let expected = 6
let sum = try! await withTaskGroup(of: Int.self) { (group) async -> Int in
for n in numbers {
group.addTask {
await completeSlowly(n: n)
}
}
var sum = 0
print("before group.next(), sum: \(sum)")
while let n = try! await group.next() {
assert(numbers.contains(n), "Unexpected value: \(n)! Expected any of \(numbers)")
print("next: \(n)")
sum += n
print("before group.next(), sum: \(sum)")
}
print("task group returning: \(sum)")
return sum
}
// The completions are set apart by n seconds, so we expect them to arrive
// in the order as the numbers (and delays) would suggest:
// CHECK: task group returning: 6
// CHECK: result: 6
print("result: \(sum)")
assert(sum == expected, "Expected: \(expected), got: \(sum)")
}
@main struct Main {
static func main() async {
await test_sum_nextOnPending()
}
}
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