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// RUN: %target-run-simple-swift( %import-libdispatch -parse-as-library -sanitize=thread)
// REQUIRES: executable_test
// REQUIRES: concurrency
// REQUIRES: libdispatch
// REQUIRES: tsan_runtime
// UNSUPPORTED: use_os_stdlib
var scratchBuffer: UnsafeMutableBufferPointer<Int> = .allocate(capacity: 1000)
@available(SwiftStdlib 5.1, *)
func completeFastOrSlow(n: Int) async -> Int {
if n % 2 == 0 {
await Task.sleep(2_000_000_000)
}
assert(scratchBuffer[n] == 6)
scratchBuffer[n] = 7
return n
}
@available(SwiftStdlib 5.1, *)
func test_sum_nextOnCompletedOrPending() async {
scratchBuffer.initialize(repeating: 0)
let numbers = 0..<1000
let expected = 499_500
let sum = await withTaskGroup(of: Int.self) { (group) async -> Int in
for n in numbers {
scratchBuffer[n] = 6
await group.spawn {
let res = await completeFastOrSlow(n: n)
return res
}
}
// We want to await on completed and pending child tasks. This gives the
// fast tasks some time to complete before we call group.next().
await Task.sleep(1_000_000_000)
var sum = 0
while let r = try! await group.next() {
assert(scratchBuffer[r] == 7)
sum += r
}
assert(group.isEmpty, "Group must be empty after we consumed all tasks")
print("task group returning: \(sum)")
return sum
}
print("result: \(sum)")
assert(sum == expected, "Expected: \(expected), got: \(sum)")
}
@available(SwiftStdlib 5.1, *)
@main struct Main {
static func main() async {
await test_sum_nextOnCompletedOrPending()
}
}
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