If you have mutable stated, shared over isolation domains that can't live on the MainActor and you can await to access it. Actors might be a good option. Then they also have cool tricks, like using DispatchQueue which makes it easy to use queue based APIs
March 17, 2026 at 9:30 AM
If you have mutable stated, shared over isolation domains that can't live on the MainActor and you can await to access it. Actors might be a good option. Then they also have cool tricks, like using DispatchQueue which makes it easy to use queue based APIs
💡 From an execution model perspective, Actor is similar to a compile-time safe serial DispatchQueue.
Want to integrate Actor with legacy APIs like Combine or Core Data? You can use a custom SerialExecutor to make them share the same queue. 🧵👇
Want to integrate Actor with legacy APIs like Combine or Core Data? You can use a custom SerialExecutor to make them share the same queue. 🧵👇
December 11, 2025 at 1:32 PM
💡 From an execution model perspective, Actor is similar to a compile-time safe serial DispatchQueue.
Want to integrate Actor with legacy APIs like Combine or Core Data? You can use a custom SerialExecutor to make them share the same queue. 🧵👇
Want to integrate Actor with legacy APIs like Combine or Core Data? You can use a custom SerialExecutor to make them share the same queue. 🧵👇
Apparently I had to use DispatchQueue with a DispatchWorkItem instead of the newer asynchronous SwiftUI syntax. The newer form wasn't working properly in macOS when I tested. So here is the code with the older (and it seems more reliable) way of doing this:
November 27, 2025 at 5:29 PM
Apparently I had to use DispatchQueue with a DispatchWorkItem instead of the newer asynchronous SwiftUI syntax. The newer form wasn't working properly in macOS when I tested. So here is the code with the older (and it seems more reliable) way of doing this:
It shows how to simulate a hang in SwiftUI, detect it using App Hangs Detection and Instruments, and fix it by moving computations to a background thread using DispatchQueue.
#ios #iosdevelopment #swift #swiftui #swiftlang #UIHangs #AppHangsDetection #Instruments
#ios #iosdevelopment #swift #swiftui #swiftlang #UIHangs #AppHangsDetection #Instruments
April 18, 2025 at 7:30 AM
It shows how to simulate a hang in SwiftUI, detect it using App Hangs Detection and Instruments, and fix it by moving computations to a background thread using DispatchQueue.
#ios #iosdevelopment #swift #swiftui #swiftlang #UIHangs #AppHangsDetection #Instruments
#ios #iosdevelopment #swift #swiftui #swiftlang #UIHangs #AppHangsDetection #Instruments
I’ve known a few of these guys. One was really bad. He once gave a talk to the team that we should never use DispatchQueue. Then said we should use RxSwift.
It runs sequences which are scheduled on DispatchQueues. He also put everything on main with blocking code all the time.
It runs sequences which are scheduled on DispatchQueues. He also put everything on main with blocking code all the time.
February 26, 2025 at 1:15 AM
I’ve known a few of these guys. One was really bad. He once gave a talk to the team that we should never use DispatchQueue. Then said we should use RxSwift.
It runs sequences which are scheduled on DispatchQueues. He also put everything on main with blocking code all the time.
It runs sequences which are scheduled on DispatchQueues. He also put everything on main with blocking code all the time.
Parts 1-2/2 — EFTA02367480.jpg
#epsteinweb #efta02367480
https://epsteinweb.org
Available in the iOS app store now!
https://apps.apple.com/us/app/epstein-web/id6758880661
#epsteinweb #efta02367480
https://epsteinweb.org
Available in the iOS app store now!
https://apps.apple.com/us/app/epstein-web/id6758880661
![EFTA02367479 | EFTA02367480
18 _psynch_cvwait + 10 =libsystemkernel.dylib + 90422) [0x7fff8f3b1136] 1-18
=nbsp; *18 psynch_cvcontinue + 0 (pthread + 26908) =Oxffffff7f8Ode291c] 1-18
Thread =x50875d DispatchQueue 2 18 samples (1-18) =nbsp; priority 47
<frontmost, thread QoS user =nteractive, boosted, received importance donation from WindowServer =1051, 10 policy
important>
18 =nbsp;_dispatch_mgr_thread + 52 (libdispatch.dylib + 19050) =0x7f1f94352a6a] 1-18
18 kevent64 + 10 =libsystem_kernel.dylib + 94770)10x7fff8f3b2232] 1-18
=nbsp; *18 ??? (kernel + 5988368)10xffffff80007b60101=-18
Thread 0x508760 18 =amples (1-18) priority 31
<frontmost, thread =oS legacy, boosted, received importance donation from WindowServer =1051, 10 policy
important>
18 thread_start + =3 (libsystem_pthread.dylib + 5149) (0x7fff92fe541d1 =-18
18 _pthread_start + 176 =libsystem_pthread.dylib + 12773) [0x7fff92fe71e51 1-18
=nbsp; 18 ??? (<390A2BB0-CAA4-3FFD-B19B-ED15A8313953> = 31518289)10x10360ee511 1-18
18 =nbsp;mach_msg_trap + 10 (libsystem_kernel.dylib + 70878) =0x7fff8f3ac4de] 1-18
*18 =nbsp;ipc_mqueue_receive_continue + 0 (kernel + 1165472) =Oxffffff800031c8a0) 1-18
Thread =x508766 18 samples (1-18) priority =1
<frontmost, thread O05 legacy, boosted, received =mportance donation from WindowServer 11051, 10 policy
=mportant>
18 kevent + 10 =libsystem_kernel.dylib + 94746)[0x7fff8f3b221a] 1-18
=nbsp;*18 ??? (kernel + 5988368) [Oxffffff80007b6010] =-18
Thread 0x50876a 18 =amples (1-18) priority 31
cpu time =.001s
<frontmost, thread QoS legacy, boosted, =eceived importance donation from WindowServer 11051, 10 policy
=mportant>
18 _select + 10 =libsystem_kernel.dylib + 91130)10x7fff8f3b13fa1 1-18
=nbsp;'18 ??? (kernel + 6142240) [Oxffffff80007db9201=-18
Thread 0x50876b 18 =amples (1-18) priority 31
<frontmost, thread =oS legacy, boosted, received importance donation from WindowServer =1051, 10 policy
important>
18 ??? =<65089470-2121-3976-A28C-971F1EE096A0> + 2103527) (0x1007018e7J =-18
18](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:ndjyym3ihrqu3g25gdztefrv/bafkreierzaihqu32gvlhztm5zn67icotocwypq7bski47uykrd2aj26gfi)
April 6, 2026 at 8:36 PM
Parts 1-2/2 — EFTA02367480.jpg
#epsteinweb #efta02367480
https://epsteinweb.org
Available in the iOS app store now!
https://apps.apple.com/us/app/epstein-web/id6758880661
#epsteinweb #efta02367480
https://epsteinweb.org
Available in the iOS app store now!
https://apps.apple.com/us/app/epstein-web/id6758880661
Simplified:
public class Log {
private let queue = DispatchQueue(label:"log")
public func log( _ msg: String ) {
queue.async {
writeStringToFile(msg)
}
}
Log entries get written in their entirety and in order† without locking up the current thread.
†For each calling thread
public class Log {
private let queue = DispatchQueue(label:"log")
public func log( _ msg: String ) {
queue.async {
writeStringToFile(msg)
}
}
Log entries get written in their entirety and in order† without locking up the current thread.
†For each calling thread
January 12, 2025 at 8:20 PM
Simplified:
public class Log {
private let queue = DispatchQueue(label:"log")
public func log( _ msg: String ) {
queue.async {
writeStringToFile(msg)
}
}
Log entries get written in their entirety and in order† without locking up the current thread.
†For each calling thread
public class Log {
private let queue = DispatchQueue(label:"log")
public func log( _ msg: String ) {
queue.async {
writeStringToFile(msg)
}
}
Log entries get written in their entirety and in order† without locking up the current thread.
†For each calling thread
I've been using the Sonnet integration in Xcode so that I can tell it to build the boring to construct bits of the UI and also tell it to port my older code base to swift 6.x idioms (Task instead of DispatchQueue, await async instead of callbacks, etc) and it mostly just works.
December 30, 2025 at 12:39 AM
I've been using the Sonnet integration in Xcode so that I can tell it to build the boring to construct bits of the UI and also tell it to port my older code base to swift 6.x idioms (Task instead of DispatchQueue, await async instead of callbacks, etc) and it mostly just works.
On Windows, there's still a delay of up to 15ms between "typesetting completed" and page drawing. I had hoped the issue with DispatchQueue/MainRunLoop integration had been solved by this commit, but it doesn't look like it: github.com/ktraunmuelle...
I need to try something else.
I need to try something else.
February 1, 2026 at 9:32 AM
On Windows, there's still a delay of up to 15ms between "typesetting completed" and page drawing. I had hoped the issue with DispatchQueue/MainRunLoop integration had been solved by this commit, but it doesn't look like it: github.com/ktraunmuelle...
I need to try something else.
I need to try something else.
Project: facebook/react
File: packages/react-dom-bindings/src/events/plugins/SelectEventPlugin.js:150
function extractEvents( dispatchQueue: DispatchQueue, domEventName: DOMEvent...
SVG: dark, light
File: packages/react-dom-bindings/src/events/plugins/SelectEventPlugin.js:150
function extractEvents( dispatchQueue: DispatchQueue, domEventName: DOMEvent...
SVG: dark, light
December 22, 2025 at 3:38 AM
Project: facebook/react
File: packages/react-dom-bindings/src/events/plugins/SelectEventPlugin.js:150
function extractEvents( dispatchQueue: DispatchQueue, domEventName: DOMEvent...
SVG: dark, light
File: packages/react-dom-bindings/src/events/plugins/SelectEventPlugin.js:150
function extractEvents( dispatchQueue: DispatchQueue, domEventName: DOMEvent...
SVG: dark, light
Project: facebook/react
File: packages/react-dom-bindings/src/events/plugins/ScrollEndEventPlugin.js:123
function extractEvents( dispatchQueue: DispatchQueue, domEventName: DOMEv...
SVG: dark, light
File: packages/react-dom-bindings/src/events/plugins/ScrollEndEventPlugin.js:123
function extractEvents( dispatchQueue: DispatchQueue, domEventName: DOMEv...
SVG: dark, light
October 22, 2025 at 6:44 PM
Project: facebook/react
File: packages/react-dom-bindings/src/events/plugins/ScrollEndEventPlugin.js:123
function extractEvents( dispatchQueue: DispatchQueue, domEventName: DOMEv...
SVG: dark, light
File: packages/react-dom-bindings/src/events/plugins/ScrollEndEventPlugin.js:123
function extractEvents( dispatchQueue: DispatchQueue, domEventName: DOMEv...
SVG: dark, light
Project: facebook/react
File: packages/react-dom-bindings/src/events/plugins/ChangeEventPlugin.js:287
function extractEvents( dispatchQueue: DispatchQueue, domEventName: DOMEvent...
SVG: dark, light
File: packages/react-dom-bindings/src/events/plugins/ChangeEventPlugin.js:287
function extractEvents( dispatchQueue: DispatchQueue, domEventName: DOMEvent...
SVG: dark, light
September 30, 2025 at 3:42 AM
Project: facebook/react
File: packages/react-dom-bindings/src/events/plugins/ChangeEventPlugin.js:287
function extractEvents( dispatchQueue: DispatchQueue, domEventName: DOMEvent...
SVG: dark, light
File: packages/react-dom-bindings/src/events/plugins/ChangeEventPlugin.js:287
function extractEvents( dispatchQueue: DispatchQueue, domEventName: DOMEvent...
SVG: dark, light
Project: facebook/react
File: packages/react-dom-bindings/src/events/plugins/SelectEventPlugin.js:150
function extractEvents( dispatchQueue: DispatchQueue, domEventName: DOMEvent...
SVG: dark, light
File: packages/react-dom-bindings/src/events/plugins/SelectEventPlugin.js:150
function extractEvents( dispatchQueue: DispatchQueue, domEventName: DOMEvent...
SVG: dark, light
August 17, 2025 at 10:39 AM
Project: facebook/react
File: packages/react-dom-bindings/src/events/plugins/SelectEventPlugin.js:150
function extractEvents( dispatchQueue: DispatchQueue, domEventName: DOMEvent...
SVG: dark, light
File: packages/react-dom-bindings/src/events/plugins/SelectEventPlugin.js:150
function extractEvents( dispatchQueue: DispatchQueue, domEventName: DOMEvent...
SVG: dark, light
Super interesting, without Parallelism I got a time of 10.6 seconds. After using DispatchQueue in Swift and running each potential path in parallel, I got it down to 1.6 seconds.
December 7, 2024 at 9:26 AM
Super interesting, without Parallelism I got a time of 10.6 seconds. After using DispatchQueue in Swift and running each potential path in parallel, I got it down to 1.6 seconds.
이야 나 objc 다 까먹었네? DispatchQueue 생각이 안나서 얼타고 있음.
September 5, 2025 at 2:07 AM
이야 나 objc 다 까먹었네? DispatchQueue 생각이 안나서 얼타고 있음.
Is there a way to get something like a sequential DispatchQueue in Swift on Android (Kotlin)?
It seems a bit odd to have to block on a mutex *inside* a coroutine to ensure they run in order, instead of somehow restricting the coroutine to wait for the previous one to complete its run […]
It seems a bit odd to have to block on a mutex *inside* a coroutine to ensure they run in order, instead of somehow restricting the coroutine to wait for the previous one to complete its run […]
Original post on chaos.social
chaos.social
February 17, 2025 at 11:58 AM
Is there a way to get something like a sequential DispatchQueue in Swift on Android (Kotlin)?
It seems a bit odd to have to block on a mutex *inside* a coroutine to ensure they run in order, instead of somehow restricting the coroutine to wait for the previous one to complete its run […]
It seems a bit odd to have to block on a mutex *inside* a coroutine to ensure they run in order, instead of somehow restricting the coroutine to wait for the previous one to complete its run […]
As smart and bulky our IDE's become and after so many years of working in Xcode, it still doesn't recognise this is my "go to" DispatchQueue 😂
`DispatchQueue.main.asyncAfter(wallDeadline: .now() + 0.3)` {
// Do something funky!
}`
#SwiftUI, #buildinpublic
`DispatchQueue.main.asyncAfter(wallDeadline: .now() + 0.3)` {
// Do something funky!
}`
#SwiftUI, #buildinpublic
March 25, 2025 at 10:17 AM
As smart and bulky our IDE's become and after so many years of working in Xcode, it still doesn't recognise this is my "go to" DispatchQueue 😂
`DispatchQueue.main.asyncAfter(wallDeadline: .now() + 0.3)` {
// Do something funky!
}`
#SwiftUI, #buildinpublic
`DispatchQueue.main.asyncAfter(wallDeadline: .now() + 0.3)` {
// Do something funky!
}`
#SwiftUI, #buildinpublic
Discover how dispatchQueue.sync can cause deadlocks and learn techniques to avoid them if you're not ready to use Swift Concurrency yet. Read more: https://www.donnywals.com/understanding-how-dispatchqueue-sync-can-cause-deadlocks/
May 8, 2025 at 11:19 AM
Discover how dispatchQueue.sync can cause deadlocks and learn techniques to avoid them if you're not ready to use Swift Concurrency yet. Read more: https://www.donnywals.com/understanding-how-dispatchqueue-sync-can-cause-deadlocks/
Infelizmente std::async cria um thread novo a cada chamada 🫠 Então eu criei uma implementação de #DispatchQueue / #ThreadPool que é bem simples, mas muito bacana de usar, pra evitar criação de threads todo frame na minha #gameengine de #ECS + #SQL 🚀
github.com/gilzoide/cpp...
#gamedev #C++
github.com/gilzoide/cpp...
#gamedev #C++
GitHub - gilzoide/cpp-dispatch-queue: Dispatch Queue / Thread Pool implementation for C++11
Dispatch Queue / Thread Pool implementation for C++11 - gilzoide/cpp-dispatch-queue
github.com
February 14, 2025 at 11:08 AM
Infelizmente std::async cria um thread novo a cada chamada 🫠 Então eu criei uma implementação de #DispatchQueue / #ThreadPool que é bem simples, mas muito bacana de usar, pra evitar criação de threads todo frame na minha #gameengine de #ECS + #SQL 🚀
github.com/gilzoide/cpp...
#gamedev #C++
github.com/gilzoide/cpp...
#gamedev #C++
Turns out std::async creates a new thread in every call on most platforms. So I've created a standalone, simple and very nice to use #DispatchQueue / #ThreadPool implementation to avoid thread creation every frame in my #ECS + #SQL #gameengine 🚀
github.com/gilzoide/cpp...
#C++ #gamedev
github.com/gilzoide/cpp...
#C++ #gamedev
GitHub - gilzoide/cpp-dispatch-queue: Dispatch Queue / Thread Pool implementation for C++11
Dispatch Queue / Thread Pool implementation for C++11 - gilzoide/cpp-dispatch-queue
github.com
February 14, 2025 at 11:05 AM
Turns out std::async creates a new thread in every call on most platforms. So I've created a standalone, simple and very nice to use #DispatchQueue / #ThreadPool implementation to avoid thread creation every frame in my #ECS + #SQL #gameengine 🚀
github.com/gilzoide/cpp...
#C++ #gamedev
github.com/gilzoide/cpp...
#C++ #gamedev
When you use DispatchQueue in Swift Concurrency it’s most likely wrong or unnecessary. DispatchQueue is the old way of doing async work. It works but you should avoid it. Not sure how to explain it better 😅
June 17, 2025 at 12:20 AM
When you use DispatchQueue in Swift Concurrency it’s most likely wrong or unnecessary. DispatchQueue is the old way of doing async work. It works but you should avoid it. Not sure how to explain it better 😅
i was learning swift at the time and loved the DispatchQueue system, how amazingly easy to use the API is, how it handles serial/multithreaded queues, how it has native language support so it's integrated nicely into the xcode debugger
and i thought... why not build that... but in a much worse way!
and i thought... why not build that... but in a much worse way!
January 11, 2025 at 8:41 AM
i was learning swift at the time and loved the DispatchQueue system, how amazingly easy to use the API is, how it handles serial/multithreaded queues, how it has native language support so it's integrated nicely into the xcode debugger
and i thought... why not build that... but in a much worse way!
and i thought... why not build that... but in a much worse way!
I just published GCD, OperationQueue, Swift Concurrency. medium.com/p/gcd-operat...
#iOS #Swift #GCD #iOSDev #SwiftConcurrency #DispatchQueue #OperationQueue #iOSInterview #Actor #AsyncAwait #MainActor #Sendable #TechInterview #MobileDevelopment #SoftwareEngineering
#iOS #Swift #GCD #iOSDev #SwiftConcurrency #DispatchQueue #OperationQueue #iOSInterview #Actor #AsyncAwait #MainActor #Sendable #TechInterview #MobileDevelopment #SoftwareEngineering
GCD, OperationQueue, Swift Concurrency.
iOS concurrency interviews span 15 years of APIs — from raw threads to GCD queues, OperationQueue dependencies, and Swift’s structured…
medium.com
March 24, 2026 at 2:19 AM
I just published GCD, OperationQueue, Swift Concurrency. medium.com/p/gcd-operat...
#iOS #Swift #GCD #iOSDev #SwiftConcurrency #DispatchQueue #OperationQueue #iOSInterview #Actor #AsyncAwait #MainActor #Sendable #TechInterview #MobileDevelopment #SoftwareEngineering
#iOS #Swift #GCD #iOSDev #SwiftConcurrency #DispatchQueue #OperationQueue #iOSInterview #Actor #AsyncAwait #MainActor #Sendable #TechInterview #MobileDevelopment #SoftwareEngineering
2/2
Na ja, immerhin bin ich jetzt weiter und kenne nun so manche Kuriosität.
Bspw. gibt der Initializer der DispatchQueue Class ein Object zurück, das abhängig von den Werten (!) der übergebenen Parametern (also nicht mal Overloading) true für den Ausdruck "newQueue is DispatchSerialQueue" …
2/3
Na ja, immerhin bin ich jetzt weiter und kenne nun so manche Kuriosität.
Bspw. gibt der Initializer der DispatchQueue Class ein Object zurück, das abhängig von den Werten (!) der übergebenen Parametern (also nicht mal Overloading) true für den Ausdruck "newQueue is DispatchSerialQueue" …
2/3
October 10, 2024 at 8:20 PM
2/2
Na ja, immerhin bin ich jetzt weiter und kenne nun so manche Kuriosität.
Bspw. gibt der Initializer der DispatchQueue Class ein Object zurück, das abhängig von den Werten (!) der übergebenen Parametern (also nicht mal Overloading) true für den Ausdruck "newQueue is DispatchSerialQueue" …
2/3
Na ja, immerhin bin ich jetzt weiter und kenne nun so manche Kuriosität.
Bspw. gibt der Initializer der DispatchQueue Class ein Object zurück, das abhängig von den Werten (!) der übergebenen Parametern (also nicht mal Overloading) true für den Ausdruck "newQueue is DispatchSerialQueue" …
2/3
13 rules to make AI write safe, modern Swift.
async/await over callbacks. Actors over DispatchQueue. @MainActor for UI. No force unwraps. Privacy strings that ship.
https://gist.github.com/oliviacraft/09dc3cb60c975a35cfb68196ca6b379d
#Swift #iOS #ClaudeAI
async/await over callbacks. Actors over DispatchQueue. @MainActor for UI. No force unwraps. Privacy strings that ship.
https://gist.github.com/oliviacraft/09dc3cb60c975a35cfb68196ca6b379d
#Swift #iOS #ClaudeAI
May 4, 2026 at 10:18 PM
13 rules to make AI write safe, modern Swift.
async/await over callbacks. Actors over DispatchQueue. @MainActor for UI. No force unwraps. Privacy strings that ship.
https://gist.github.com/oliviacraft/09dc3cb60c975a35cfb68196ca6b379d
#Swift #iOS #ClaudeAI
async/await over callbacks. Actors over DispatchQueue. @MainActor for UI. No force unwraps. Privacy strings that ship.
https://gist.github.com/oliviacraft/09dc3cb60c975a35cfb68196ca6b379d
#Swift #iOS #ClaudeAI