diff --git a/releases/next/docs/native-modules-ios.html b/releases/next/docs/native-modules-ios.html index 4b7fe13155b..62b3e76e159 100644 --- a/releases/next/docs/native-modules-ios.html +++ b/releases/next/docs/native-modules-ios.html @@ -77,7 +77,7 @@ CalendarManager.updateEvents();

Threading #

The native module should not have any assumptions about what thread it is being called on. React Native invokes native modules methods on a separate serial GCD queue, but this is an implementation detail and might change. The - (dispatch_queue_t)methodQueue method allows the native module to specify which queue its methods should be run on. For example, if it needs to use a main-thread-only iOS API, it should specify this via:

- (dispatch_queue_t)methodQueue { return dispatch_get_main_queue(); -}

Similarly, if an operation may take a long time to complete, the native module should not block and can specify it's own queue to run operations on. For example, the RCTAsyncLocalStorage module creates it's own queue so the React queue isn't blocked waiting on potentially slow disk access:

- (dispatch_queue_t)methodQueue +}

Similarly, if an operation may take a long time to complete, the native module should not block and can specify it's own queue to run operations on. For example, the RCTAsyncLocalStorage module creates its own queue so the React queue isn't blocked waiting on potentially slow disk access:

- (dispatch_queue_t)methodQueue { return dispatch_queue_create("com.facebook.React.AsyncLocalStorageQueue", DISPATCH_QUEUE_SERIAL); }

The specified methodQueue will be shared by all of the methods in your module. If just one of your methods is long-running (or needs to be run on a different queue than the others for some reason), you can use dispatch_async inside the method to perform that particular method's code on another queue, without affecting the others:

RCT_EXPORT_METHOD(doSomethingExpensive:(NSString *)param callback:(RCTResponseSenderBlock)callback)