Ios 多线程环境中的PersistentStore协调器原因“；“未找到店铺”；崩溃
ManagedobjectcontextIos 多线程环境中的PersistentStore协调器原因“；“未找到店铺”；崩溃,ios,multithreading,core-data,Ios,Multithreading,Core Data,Managedobjectcontextsave:对NSOperation子类的查询导致此异常。我不确定这里出了什么问题，但似乎是线程锁定问题。有人能帮我解决这个问题吗 多个子类使用一个PSC，每个子类都有自己的MOC。也许我需要把@synchronized放在某个地方以保证线程安全 Fatal Exception: NSInternalInconsistencyException This NSPersistentStoreCoordinator has no persistent stor
save:NSOperation@synchronizedFatal Exception: NSInternalInconsistencyException
This NSPersistentStoreCoordinator has no persistent stores. It cannot perform a save operation.
Thread : Fatal Exception: NSInternalInconsistencyException
0 CoreFoundation 0x3018af0b __exceptionPreprocess + 130
1 libobjc.A.dylib 0x3a921ce7 objc_exception_throw + 38
2 CoreData 0x2fedd689 -[NSPersistentStoreCoordinator executeRequest:withContext:error:] + 3228
3 CoreData 0x2fefef49 -[NSManagedObjectContext save:] + 824
4 ChevronRetail 0x0006aae5 -[MyParseOperation myMethod:] (MyParseOperation.m:159)
5 ChevronRetail 0x0006adbf -[MyParseOperation main] (StationFinderParseOperation.m:192)
6 Foundation 0x30abe875 -[__NSOperationInternal _start:] + 772
7 Foundation 0x30b62745 __NSOQSchedule_f + 60
- (NSPersistentStoreCoordinator *)persistentStoreCoordinator {
if (_persistentStoreCoordinator != nil) {
return _persistentStoreCoordinator;
}
NSString *documentsDirectoryPath = [self applicationDocumentsDirectory];
NSString *storePath = [documentsDirectoryPath stringByAppendingPathComponent:@"MyDatabase.sqlite"];
NSURL *storeUrl = [NSURL fileURLWithPath:storePath];
NSDictionary *options = [NSDictionary dictionaryWithObjectsAndKeys:
[NSNumber numberWithBool:YES], NSMigratePersistentStoresAutomaticallyOption,
[NSNumber numberWithBool:YES], NSInferMappingModelAutomaticallyOption, nil];
NSError *error;
_persistentStoreCoordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel: [self managedObjectModel]];
if (![_persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:storeUrl options:options error:&error])
{
NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
//abort();
}
return _persistentStoreCoordinator;
}
- (NSManagedObjectContext *)managedObjectContext {
if (_managedObjectContext != nil) {
return _managedObjectContext;
}
NSPersistentStoreCoordinator *coordinator = [self persistentStoreCoordinator];
if (coordinator != nil) {
_managedObjectContext = [NSManagedObjectContext new];
[_managedObjectContext setPersistentStoreCoordinator:coordinator];
}
[_managedObjectContext setMergePolicy:NSOverwriteMergePolicy];
return _managedObjectContext;
}
苹果样板PSC初始化代码不是线程安全的（MOC初始化代码也不是线程安全的）。
您可以找到类似的问题 在多线程环境中，2个（或更多）线程可以调用PSC初始化代码。
解决方法是在“应用程序确实完成了启动…”中添加以下行：
发出使用CoreData堆栈的任何操作/流之前。
这可以确保只有一个线程（主线程）初始化堆栈，但是这否定了当前实现试图实现的“延迟加载”原则。
错误的原因是这种执行流：
线程1测试是否存在一个
\u persistentstorecordinator线程2测试是否存在一个
\u persistentstorecordinator线程1和线程2继续进入初始化代码部分。
线程1到达该行（但尚未返回）：
线程2执行该行：
_persistentStoreCoordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:[self managedObjectModel]];
为了保持“延迟加载”梦想的活力，您可以通过以下方式实现初始化代码：
//UNTESTED
- (NSPersistentStoreCoordinator *)persistentStoreCoordinator
{
if (_persistentStoreCoordinator != nil) {//someone already initilized this part of the stack
return _persistentStoreCoordinator;//no need to lock
}
@synchronized(self) {
if (_persistentStoreCoordinator == nil) {//check under lock
_persistentStoreCoordinator = [self __persistentStoreCoordinator];//only one thread could set the ivar
}
}
return _persistentStoreCoordinator;
}
- (NSPersistentStoreCoordinator*) __persistentStoreCoordinator
{
NSDictionary *options = [NSDictionary dictionaryWithObjectsAndKeys:
[NSNumber numberWithBool:YES], NSMigratePersistentStoresAutomaticallyOption,
[NSNumber numberWithBool:YES], NSInferMappingModelAutomaticallyOption, nil];
NSURL *storeURL = [[self applicationDocumentsDirectory] URLByAppendingPathComponent:@"MyDatabase.sqlite"];
NSError *error = nil;
NSPersistentStoreCoordinator* coordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:[self managedObjectModel]];
if (![coordinator addPersistentStoreWithType:NSSQLiteStoreType
configuration:nil
URL:storeURL
options:options
error:&error]) {
NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
abort();
}
return coordinator;//always return a full fledged coordinator
}
此竞争条件也适用于
managedObjectModelmanagedObjectContext解决方案类似。
添加MOC和PSC初始化代码目前没有时间形成答案，但在PSCThanks的初始化中有一个竞赛条件，这很有帮助-目前每个控制器都有自己的MOC，因此我认为不应该有竞赛条件。在将更新推送到存储区之前，是否有办法测试此代码？--问题是我在个人测试期间从未见过崩溃，但在商店中我看到了很多崩溃。在访问协调器期间暂停线程，并尝试重现您认为导致错误的竞争条件。
_persistentStoreCoordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:[self managedObjectModel]];
//UNTESTED
- (NSPersistentStoreCoordinator *)persistentStoreCoordinator
{
if (_persistentStoreCoordinator != nil) {//someone already initilized this part of the stack
return _persistentStoreCoordinator;//no need to lock
}
@synchronized(self) {
if (_persistentStoreCoordinator == nil) {//check under lock
_persistentStoreCoordinator = [self __persistentStoreCoordinator];//only one thread could set the ivar
}
}
return _persistentStoreCoordinator;
}
- (NSPersistentStoreCoordinator*) __persistentStoreCoordinator
{
NSDictionary *options = [NSDictionary dictionaryWithObjectsAndKeys:
[NSNumber numberWithBool:YES], NSMigratePersistentStoresAutomaticallyOption,
[NSNumber numberWithBool:YES], NSInferMappingModelAutomaticallyOption, nil];
NSURL *storeURL = [[self applicationDocumentsDirectory] URLByAppendingPathComponent:@"MyDatabase.sqlite"];
NSError *error = nil;
NSPersistentStoreCoordinator* coordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:[self managedObjectModel]];
if (![coordinator addPersistentStoreWithType:NSSQLiteStoreType
configuration:nil
URL:storeURL
options:options
error:&error]) {
NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
abort();
}
return coordinator;//always return a full fledged coordinator
}