https://github.com/clintjang/sample-swift-dispatchgroup
It is a repository showing a simple example using "DispatchGroup".
https://github.com/clintjang/sample-swift-dispatchgroup
dispatchgroup dispatchqueue enter gcd leave notify wait
Last synced: about 2 months ago
JSON representation
It is a repository showing a simple example using "DispatchGroup".
- Host: GitHub
- URL: https://github.com/clintjang/sample-swift-dispatchgroup
- Owner: ClintJang
- License: mit
- Created: 2019-01-31T23:50:15.000Z (about 6 years ago)
- Default Branch: master
- Last Pushed: 2019-02-01T08:54:01.000Z (about 6 years ago)
- Last Synced: 2025-01-16T19:41:40.572Z (3 months ago)
- Topics: dispatchgroup, dispatchqueue, enter, gcd, leave, notify, wait
- Language: Swift
- Size: 3.13 MB
- Stars: 4
- Watchers: 2
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
# Swift Dispatchgroup Sample
It is a repository showing a simple example using "DispatchGroup".
Jobs already in group via DispatchGroup
Wait for it to finish and use it when you expect it to be called when it's all done.
- "notify" works asynchronously.
- "wait" works synchronously.
- "queue, notify" works synchronously
## Result Image (GIF)
## Case 01 (notify)
> asynchronous
```swift
func dispatchGroupTestCase1Notify() {
writeLog("=====================\n== asynchronous")
writeLog("\(#function), start")
let dispatchGroup = DispatchGroup()
dispatchGroup.enter()
DispatchQueue.global().async { [weak self] in
guard let self = self else { return }
if self.roof20_000_000() { dispatchGroup.leave() }
}
dispatchGroup.enter()
DispatchQueue.global().async { [weak self] in
guard let self = self else { return }
if self.roof10_000_000() { dispatchGroup.leave() }
}
dispatchGroup.enter()
DispatchQueue.global().async { [weak self] in
guard let self = self else { return }
if self.roof15_000_000() { dispatchGroup.leave() }
}
dispatchGroup.notify(queue: .main) { [weak self] in
guard let self = self else { return }
self.writeLog("dispatchGroup.notify OK")
self.writeLog("\(#function), end")
}
}
```
## Case 02 (wait)
> synchronous
```swift
func dispatchGroupTestCase2Wait() {
writeLog("=====================\n== synchronous")
writeLog("\(#function), start")
let dispatchGroup = DispatchGroup()
dispatchGroup.enter()
DispatchQueue.global().async { [weak self] in
guard let self = self else { return }
if self.roof20_000_000() { dispatchGroup.leave() }
}
dispatchGroup.enter()
DispatchQueue.global().async { [weak self] in
guard let self = self else { return }
if self.roof10_000_000() { dispatchGroup.leave() }
}
dispatchGroup.enter()
DispatchQueue.global().async { [weak self] in
guard let self = self else { return }
if self.roof15_000_000() { dispatchGroup.leave() }
}
let result = dispatchGroup.wait(timeout: .distantFuture)
self.writeLog("dispatchGroup.wait OK(result::\(result))")
self.writeLog("\(#function), end")
}
```
## Case 03 (queue, notify)
> asynchronous, Do not use enter and leave.
```swift
func dispatchGroupTestCase3QueueNotify() {
writeLog("=====================\n== asynchronous")
writeLog("=====================\n== Do not use enter and leave.")
writeLog("\(#function), start")
let dispatchGroup = DispatchGroup()
let dispatchQueueGlobal = DispatchQueue.global()
dispatchQueueGlobal.async(group: dispatchGroup, execute: { [weak self] in
guard let self = self else { return }
let _ = self.roof20_000_000()
})
dispatchQueueGlobal.async(group: dispatchGroup, execute: { [weak self] in
guard let self = self else { return }
let _ = self.roof10_000_000()
})
dispatchQueueGlobal.async(group: dispatchGroup, execute: { [weak self] in
guard let self = self else { return }
let _ = self.roof15_000_000()
})
dispatchGroup.notify(queue: dispatchQueueGlobal) { [weak self] in
guard let self = self else { return }
self.writeLog("dispatchGroup.notify OK")
self.writeLog("\(#function), end")
}
}
```
## Result Log
### case 1 (notify, asynchronous)
```
2019-02-01 08:15:42 +0000::=====================
== asynchronous
2019-02-01 08:15:42 +0000::dispatchGroupTestCase1Notify(), start
2019-02-01 08:15:42 +0000::roof20_000_000(), start
2019-02-01 08:15:42 +0000::roof15_000_000(), start
2019-02-01 08:15:42 +0000::roof10_000_000(), start
2019-02-01 08:15:45 +0000::roof10_000_000(), end
2019-02-01 08:15:47 +0000::roof15_000_000(), end
2019-02-01 08:15:48 +0000::roof20_000_000(), end
2019-02-01 08:15:48 +0000::dispatchGroup.notify OK
2019-02-01 08:15:48 +0000::dispatchGroupTestCase1Notify(), end
```
### case 2 (wait, synchronous)
```
2019-02-01 08:15:49 +0000::=====================
== synchronous
2019-02-01 08:15:49 +0000::dispatchGroupTestCase2Wait(), start
2019-02-01 08:15:49 +0000::roof20_000_000(), start
2019-02-01 08:15:49 +0000::roof10_000_000(), start
2019-02-01 08:15:49 +0000::roof15_000_000(), start
2019-02-01 08:15:52 +0000::roof10_000_000(), end
2019-02-01 08:15:54 +0000::roof15_000_000(), end
2019-02-01 08:15:55 +0000::roof20_000_000(), end
2019-02-01 08:15:55 +0000::dispatchGroup.wait OK(result::success)
2019-02-01 08:15:55 +0000::dispatchGroupTestCase2Wait(), end
```
### case 3 (queue, notify, asynchronous)
```
2019-02-01 08:15:57 +0000::=====================
== asynchronous
2019-02-01 08:15:57 +0000::=====================
== Do not use enter and leave.
2019-02-01 08:15:57 +0000::dispatchGroupTestCase3QueueNotify(), start
2019-02-01 08:15:57 +0000::roof20_000_000(), start
2019-02-01 08:15:57 +0000::roof15_000_000(), start
2019-02-01 08:15:57 +0000::roof10_000_000(), start
2019-02-01 08:16:00 +0000::roof10_000_000(), end
2019-02-01 08:16:01 +0000::roof15_000_000(), end
2019-02-01 08:16:03 +0000::roof20_000_000(), end
2019-02-01 08:16:03 +0000::dispatchGroup.notify OK
2019-02-01 08:16:03 +0000::dispatchGroupTestCase3QueueNotify(), end
```