目标c中的sqlite3多线程

Question

我在我的应用程序中使用dispatch_async运行后台线程，有时我的主线程和后台线程都同时访问数据库，这给了我一个数据库错误，我试图通过使用sqlite3_threadsafe（）来解决它，它始终返回2即，我不能在两个线程中使用相同的数据库连接，我希望它返回1可以任何人在这方面帮助我

Answer 1

I think you're pursuing the wrong approach. SQLite isn't reliably threadsafe no matter how you compile it — see the FAQ . Even if SQLite is compiled for thread safety, the same database may not be used from multiple threads if any transactions are pending or any statements remain unfinalised.

The recommendations above to use Grand Central Dispatch to funnel all SQLite accesses into a serial dispatch queue are the right way to proceed in my opinion, though I'd be more likely to recommend that you create your own queue rather than use the main queue for the simple reason that you can reliably dispatch_sync when you want to wait on a result.

Answer 2

You can add all of your access statements to, therefore you are always on the main thread when access the sqlite store.

dispatch_async(dispatch_get_main_queue(), ^ {
    //code goes here
});