Question

我正在使用-com.apple.CoreData.ConcurrencyDebug 1在我的应用中查找任何CoreData并发问题。我遇到过executeFetchRequest停止的问题：

    __block NSArray *results = nil;
    [context performBlockAndWait:^{

        NSError *error = nil;

        results = [context executeFetchRequest:request error:&error];

        if (results == nil) 
        {
            [MagicalRecord handleErrors:error];
        }

    }];
    return results;

这是来自MagicalRecord library。我正在运行旧版本，但我认为我的问题是我的代码，而不是MagicalRecord。

它提供的错误是：

 Thread 1: EXC_BAD_INSTRUCTION (code=EXC_I386_INVOP, subcode=0x0)

我正在使用MagicalRecord的默认上下文，我在主线程上。我的谓词中的所有对象也来自默认上下文：

NSPredicate *predicate = [NSPredicate predicateWithFormat:@"form == %@ AND id <> 0 AND user == %@", self, user];

我假设在代码中可能会发生其他一些副作用，但我不知道在哪里可以看。要重现我的问题：

打开新视图控制器
点按取消按钮
处理操作的方法会删除一个对象（我已经注释掉了它仍会触发问题），然后它会调用一个委托方法。
该委托方法重新加载表并解除显示的控制器。
重新加载表时，会调用tableView:cellForRowAtIndexPath:，其中包含触发问题的查询。

第一次加载表时，查询没有问题。只有在打开新视图并点击取消后。

还有另一组步骤也遇到了这个问题所以我真的不确定是什么导致它。

如何调试副作用？或者，如果问题出在获取请求中，它有什么问题？

是否有任何工具可帮助诊断问题的原因/位置？

任何帮助将不胜感激。谢谢。

以下是完整的回溯：

    #0  0x0000000110630a14 in +[NSManagedObjectContext __Multithreading_Violation_AllThatIsLeftToUsIsHonor__] ()
    #1  0x0000000110600856 in -[_PFBatchFaultingArray count] ()
    #2  0x000000011097d4fe in +[NSSet setWithArray:] ()
    #3  0x000000011057b680 in -[NSManagedObjectContext executeFetchRequest:error:] ()
    #4  0x000000010b043242 in __67+[NSManagedObject(MagicalRecord) MR_executeFetchRequest:inContext:]_block_invoke at /Users/.../ios/External/MagicalRecord/Categories/NSManagedObject/NSManagedObject+MagicalRecord.m:52
    #5  0x00000001105c2127 in developerSubmittedBlockToNSManagedObjectContextPerform ()
    #6  0x00000001105c1fee in -[NSManagedObjectContext performBlockAndWait:] ()
    #7  0x000000010b04308f in +[NSManagedObject(MagicalRecord) MR_executeFetchRequest:inContext:] at /Users/.../ios/External/MagicalRecord/Categories/NSManagedObject/NSManagedObject+MagicalRecord.m:48
    #8  0x000000010b0434fa in +[NSManagedObject(MagicalRecord) MR_executeFetchRequestAndReturnFirstObject:inContext:] at /Users/.../ios/External/MagicalRecord/Categories/NSManagedObject/NSManagedObject+MagicalRecord.m:75
    #9  0x000000010b128939 in +[NSManagedObject(MagicalFinders) MR_findFirstWithPredicate:sortedBy:ascending:inContext:] at /Users/.../ios/External/MagicalRecord/Categories/NSManagedObject/NSManagedObject+MagicalFinders.m:183
    #10 0x000000010b08c066 in -[FormStructure lastInspectionByUser:] at /Users/.../ios/Sources/Models/Mogenerator/FormStructure.m:29
    #11 0x000000010b08c0fe in -[FormStructure hasDraftByUser:] at /Users/.../ios/Sources/Models/Mogenerator/FormStructure.m:34
    #12 0x000000010b0d56ac in -[FormsViewController configureCell:atIndexPath:] at /Users/.../ios/Sources/ViewControllers/MainApp/Inspections/FormsViewController.m:193
    #13 0x000000010b0d537e in -[FormsViewController tableView:cellForRowAtIndexPath:] at /Users/.../ios/Sources/ViewControllers/MainApp/Inspections/FormsViewController.m:173
    #14 0x000000010e6164f4 in -[UITableView _createPreparedCellForGlobalRow:withIndexPath:willDisplay:] ()
    #15 0x000000010e61662c in -[UITableView _createPreparedCellForGlobalRow:willDisplay:] ()
    #16 0x000000010e5ead4f in -[UITableView _updateVisibleCellsNow:isRecursive:] ()
    #17 0x000000010e61f686 in -[UITableView _performWithCachedTraitCollection:] ()
    #18 0x000000010e606344 in -[UITableView layoutSubviews] ()
    #19 0x000000010e573980 in -[UIView(CALayerDelegate) layoutSublayersOfLayer:] ()
    #20 0x000000010e1f9c00 in -[CALayer layoutSublayers] ()
    #21 0x000000010e1ee08e in CA::Layer::layout_if_needed(CA::Transaction*) ()
    #22 0x000000010e1edf0c in CA::Layer::layout_and_display_if_needed(CA::Transaction*) ()
    #23 0x000000010e1e23c9 in CA::Context::commit_transaction(CA::Transaction*) ()
    #24 0x000000010e210086 in CA::Transaction::commit() ()
    #25 0x000000010e4e519b in _afterCACommitHandler ()
    #26 0x0000000110958c37 in __CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__ ()
    #27 0x0000000110958ba7 in __CFRunLoopDoObservers ()
    #28 0x000000011094e7fb in __CFRunLoopRun ()
    #29 0x000000011094e0f8 in CFRunLoopRunSpecific ()
    #30 0x0000000113885ad2 in GSEventRunModal ()
    #31 0x000000010e4b8f09 in UIApplicationMain ()
    #32 0x000000010b07539f in main at /Users/.../ios/Sources/Application/main.m:14
    #33 0x000000011149b92d in start ()
    #34 0x000000011149b92d in start ()

CoreData并发调试器使用EXC_BAD_INSTRUCTION

0 个答案: