async_task_sleep_cancel.swift

// RUN: %target-run-simple-swift( -target %target-swift-5.1-abi-triple %import-libdispatch -parse-as-library) | %FileCheck %s --dump-input always
// REQUIRES: executable_test
// REQUIRES: concurrency
// REQUIRES: libdispatch

// rdar://76038845
// REQUIRES: concurrency_runtime
// UNSUPPORTED: back_deployment_runtime

import _Concurrency
// FIXME: should not depend on Dispatch
import Dispatch

@available(SwiftStdlib 5.1,*)
@mainstructMain{
staticletpause=500_000_000 // 500ms

staticfunc main()async{
 // CHECK: Starting!
print("Starting!")
awaittestSleepFinished()
awaittestSleepMomentary()
awaittestSleepCancelledBeforeStarted()
awaittestSleepCancelled()
}

staticfunc testSleepFinished()async{
 // CHECK-NEXT: Testing sleep that completes
print("Testing sleep that completes")
letstart=DispatchTime.now()

 // try! will fail if the task got cancelled (which shouldn't happen).
try!awaitTask.sleep(nanoseconds:UInt64(pause))

letstop=DispatchTime.now()

 // assert that at least the specified time passed since calling `sleep`
assert(stop >=(start +.nanoseconds(pause)))

 // CHECK-NEXT: Wakey wakey!
print("Wakey wakey!")
}

staticfunc testSleepMomentary()async{
 // CHECK-NEXT: Testing sleep that completes instantly
print("Testing sleep that completes instantly")

 // try! will fail if the task got cancelled (which shouldn't happen).
try!awaitTask.sleep(nanoseconds:0)

 // CHECK-NEXT: Wakey wakey!
print("Wakey wakey!")
}

staticfunc testSleepCancelledBeforeStarted()async{
 // CHECK-NEXT: Testing sleep that gets cancelled before it starts
print("Testing sleep that gets cancelled before it starts")
letsleepyTask=Task{
tryawaitTask.sleep(nanoseconds:UInt64(pause))
}

do{
 sleepyTask.cancel()
tryawait sleepyTask.value

print("Bah, weird scheduling")
}catch is CancellationError{
print("Caught the cancellation error")
}catch{
fatalError("sleep(nanoseconds:) threw some other error: \(error)")
}

 // CHECK: Cancelled!
print("Cancelled!")
}

staticfunc testSleepCancelled()async{
 // CHECK-NEXT: Testing sleep that gets cancelled before it completes
print("Testing sleep that gets cancelled before it completes")
letstart=DispatchTime.now()

letsleepyTask=Task{
tryawaitTask.sleep(nanoseconds:UInt64(pause))
}

do{
letwaiterTask=Task{
tryawait sleepyTask.value
}

letcancellerTask=Task{
awaitTask.sleep(UInt64(pause /2))
 sleepyTask.cancel()
}

tryawait waiterTask.value

fatalError("sleep(nanoseconds:) should have thrown CancellationError")
}catch is CancellationError{
 // CHECK-NEXT: Caught the cancellation error
print("Caught the cancellation error")

letstop=DispatchTime.now()

 // assert that we stopped early.
assert(stop <(start +.nanoseconds(pause)))
}catch{
fatalError("sleep(nanoseconds:) threw some other error: \(error)")
}

 // CHECK-NEXT: Cancelled!
print("Cancelled!")
}
}