applicationDidEnterBackground: and time to write on a database

When the application terminates, I write data on a database.

As from iOS 4 applicationWillTerminate: isn't called, I've put the same saving code both in applicationDidEnterBackground:开发者_开发百科 and applicationWillTerminate:

I read that the task performed in applicationDidEnterBackground: has to take a few time.

So, if the writing on the db takes more, how could I manage this?

You get 5 seconds to perform any saving etc in the applicationDidEnterBackground: method.

If you need more than 5 seconds there is this UIApplication method to request a background thread which will allow for more time to do whatever you need:

- (UIBackgroundTaskIdentifier)beginBackgroundTaskWithExpirationHandler:(void(^)(void))handler

Here is Apple's example code for this:

http://developer.apple.com/library/ios/documentation/iPhone/Conceptual/iPhoneOSProgrammingGuide/BackgroundExecution/BackgroundExecution.html#//apple_ref/doc/uid/TP40007072-CH5-SW12