Once you start migrating to the Swift 6 language mode, you'll most likely turn on strict concurrency first. Once you've done this there will be several warings and errors that you'll encounter and these errors can be confusing at times. I'll start by saying that having a solid understanding of actors, sendable, and data races is a huge advantage when you want to adopt the Swift 6 language mode. Pretty much all of the warnings you'll get in strict concurrency mode will tell you about potential issues related to running code concurrently. For an in-depth understanding of actors, sendability and...

Once you start migrating to the Swift 6 language mode, you'll most likely turn on strict concurrency first. Once you've done this there will be several warings and errors that you'll encounter and these errors can be confusing at times. I'll start by saying that having a solid understanding of actors, sendable, and data races is a huge advantage when you want to adopt the Swift 6 language mode. Pretty much all of the warnings you'll get in strict concurrency mode will tell you about potential issues related to running code concurrently. For an in-depth understanding of actors, sendability and...

Once you start migrating to the Swift 6 language mode, you'll most likely turn on strict concurrency first. Once you've done this there will be several warings and errors that you'll encounter and these errors can be confusing at times. I'll start by saying that having a solid understanding of actors, sendable, and data races is a huge advantage when you want to adopt the Swift 6 language mode. Pretty much all of the warnings you'll get in strict concurrency mode will tell you about potential issues related to running code concurrently. For an in-depth understanding of actors, sendability and...

Once you start migrating to the Swift 6 language mode, you'll most likely turn on strict concurrency first. Once you've done this there will be several warings and errors that you'll encounter and these errors can be confusing at times. I'll start by saying that having a solid understanding of actors, sendable, and data races is a huge advantage when you want to adopt the Swift 6 language mode. Pretty much all of the warnings you'll get in strict concurrency mode will tell you about potential issues related to running code concurrently. For an in-depth understanding of actors, sendability and...

Once you start migrating to the Swift 6 language mode, you'll most likely turn on strict concurrency first. Once you've done this there will be several warings and errors that you'll encounter and these errors can be confusing at times. I'll start by saying that having a solid understanding of actors, sendable, and data races is a huge advantage when you want to adopt the Swift 6 language mode. Pretty much all of the warnings you'll get in strict concurrency mode will tell you about potential issues related to running code concurrently. For an in-depth understanding of actors, sendability and...

In Xcode 16, this error actually is sometimes presented as "Passing closure as a 'sending' parameter risks causing data races between code in the current task and concurrent execution of the closure". The cause is the exact same as what's covered in this post. Once you start migrating to the Swift 6 language mode, you'll most likely turn on strict concurrency first. Once you've done this there will be several warnings and errors that you'll encounter and these errors can be confusing at times. I'll start by saying that having a solid understanding of actors, sendable, and data races is...

If you want to make sure that your code adopts Swift concurrency as correctly as possible in Swift 5.x, it's a good idea to enable the Strict Concurrency Checking (SWIFT_STRICT_CONCURRENCY) flag in your project. To do this, select your project's target and navigate to the Build Settings tab. Make sure you select All from the list of settings that is shown (Basic is the default) and type Strict Concurrency in the searchbar to find the Strict Concurrency Checking build setting. The screenshot below shows all the relevant parts for you to see: The default value for this setting is Minimal...

One of the goals of the Swift team with Swift’s concurrency features is to provide a model that allows developer to write safe code by default. This means that there’s a lot of time and energy invested into making sure that the Swift compiler helps developers detect, and prevent whole classes of bugs and concurrency issues altogether. One of the features that helps you prevent data races (a common concurrency issue) comes in the form of actors which I’ve written about before. While actors are great when you want to synchronize access to some mutable state, they don’t solve every...

We all know that async / await was one of this year’s big announcements WWDC. It completely changes the way we interact with concurrent code. Instead of using completion handlers, we can await results in a non-blocking way. More importantly, with the new Swift Concurrency features, our Swift code is much safer and consistent than ever before. For example, the Swift team built an all-new threading model that ensures your program doesn’t spawn more threads than there are CPU cores to avoid thread explosion. This is a huge difference from GCD where every call to async would spawn a new...