I created a function to add my course events to the calendar app using EventKit.
After learning the swift concurrency, I want to update my code to make the progress much faster, namely using the detached task or TaskGroup to add these events.
Synchronize code without detached task or task group:
func export_test() {
Task.detached {
for i in 0...15 {
print("Task \(i): Start")
let courseEvent = EKEvent(eventStore: eventStore)
courseEvent.title = "TEST"
courseEvent.location = "TEST LOC"
courseEvent.startDate = .now
courseEvent.endDate = .now.addingTimeInterval(3600)
courseEvent.calendar = eventStore.defaultCalendarForNewEvents
courseEvent.addRecurrenceRule(EKRecurrenceRule(recurrenceWith: .daily, interval: 1, end: nil))
do {
try eventStore.save(courseEvent, span: .futureEvents)
} catch { print(error.localizedDescription) }
print("Task \(i): Finished")
}
}
}
Doing the same thing using the TaskGroup :
func export_test() {
Task.detached {
await withTaskGroup(of: Void.self) { group in
for i in 0...15 {
group.addTask {
print("Task \(i): Start")
let courseEvent = EKEvent(eventStore: eventStore)
courseEvent.title = "TEST"
courseEvent.location = "TEST LOC"
courseEvent.startDate = .now
courseEvent.endDate = .now.addingTimeInterval(3600)
courseEvent.calendar = eventStore.defaultCalendarForNewEvents
courseEvent.addRecurrenceRule(EKRecurrenceRule(recurrenceWith: .daily, interval: 1, end: nil))
do {
try eventStore.save(courseEvent, span: .futureEvents)
} catch { print(error.localizedDescription) }
print("Task \(i): Finished")
}
}
}
}
}
The output of the TaskGroup version:
Task 0: Start
Task 1: Start
Task 2: Start
Task 4: Start
Task 3: Start
Task 5: Start
Task 6: Start
Task 7: Start
Task 0: Finished
Task 8: Start
Task 1: Finished
Task 9: Start
Sometimes, only a few tasks will been done, and others will not, or even never been started (I created 16 tasks but only printed 9 in this example). Sometimes, all of these events can be added.
In my point of view, I have created 16 child tasks in the TaskGroup.
Each child task will add one event to the Calendar. I think in this way, I can take the full advantage of the multi-core performance (maybe it's actually not. 🙃)
If I put the for-loop inside the group.addTask closure, it will always have the expected result, but in this way, we only have a single loop so the TaskGroup may no longer needed.
I'm really exhausted🙃🙃.