Sporadic Crash Reset Permanent Stores between Unit Test Cases (RestKit)

I apologize in advance that this probably will not ultimately make a big contribution to the general knowledge base, but I am looking for help in diagnosing what is probably related to the supervision of the configuration, due to which single instances are repeated tests.

I configured using RestKit with an object storage in memory during unit testing, so after each test case I can reset to store my persistent stores, and each test can work with a fresh database. In most cases, my test suite works without problems, but often enough to be a transaction breaker. There was a failure due to which [I think] overfulfilled the context of the managed entity. All relevant accident codes and data are below:

Unit Test Setting the base class

@implementation MyTestCase

- (void)setUp
{
    [super setUp];

    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        [[MyObjectManager sharedManager] start];
    });
}

- (void)tearDown
{
    [super tearDown];

    [[MyObjectManager sharedManager] reset];
}

Relevant MyObjectManager Setting

@interface MyObjectManager : RKObjectManager

- (void)start
{
    RKManagedObjectStore *managedObjectStore = [[RKManagedObjectStore alloc] initWithPersistentStoreCoordinator:[self persistentStoreCoordinator]];
    self.managedObjectStore = managedObjectStore;
    [managedObjectStore createManagedObjectContexts];

    [RKManagedObjectStore setDefaultStore:managedObjectStore];
}

- (NSPersistentStoreCoordinator *)persistentStoreCoordinator
{
    if (_persistentStoreCoordinator != nil)
    {
        return _persistentStoreCoordinator;
    }

    NSURL *storeURL = [[self applicationDocumentsDirectory] URLByAppendingPathComponent:kRDPersistentStore];

    _persistentStoreCoordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:[self managedObjectModel]];

    NSDictionary *options = @{
                              NSSQLitePragmasOption : @{
                                      @"synchronous" : @"FULL",
                                      @"fullfsync" : @(1)
                                      },
                              NSMigratePersistentStoresAutomaticallyOption : @YES,
                              NSInferMappingModelAutomaticallyOption : @YES
                              };

    NSError *error = nil;
    if (![self persistentStoreAtPath:storeURL options:options error:error])
    {
        NSLog(@"Error adding store %@: %@, %@", storeURL, error, [error userInfo]);
        // Additional handling
    }

    return _persistentStoreCoordinator;
}

- (NSPersistentStore *)persistentStoreAtPath:(NSURL *)storeURL options:(NSDictionary *)options error:(NSError *)error
{
    // (NSSQLiteStoreType and storeUrl are used if we're not unit testing)
    return [_persistentStoreCoordinator addPersistentStoreWithType:NSInMemoryStoreType
                                                     configuration:nil
                                                               URL:nil
                                                           options:options
                                                             error:&error];
}

MyObjectManager :: reset Implementation

- (void)reset
{
    [[RKObjectManager sharedManager].operationQueue cancelAllOperations];

    NSError *error = nil;
    [[RKManagedObjectStore defaultStore] resetPersistentStores:&error];

    if (error)
    {
        NSLog(@"Error! : %@", error);
    }

    [[NSURLCache sharedURLCache] removeAllCachedResponses];
}

Typical Failure Report

Crashed Thread:  0  Dispatch queue: com.apple.main-thread

Exception Type:  EXC_CRASH (SIGSEGV)
Exception Codes: 0x0000000000000000, 0x0000000000000000

Application Specific Information:
iPhone Simulator 463.9.41, iPhone OS 7.1 (iPhone Retina (4-inch)/11D167)

The main thread rotates the execution loop, waiting for an asynchronous test case: (Not always, but most of our tests use this method)

Thread : com.apple.main-thread
0  libsystem_kernel.dylib         0x047f6f92 semaphore_signal_trap + 10
1  libdispatch.dylib              0x0447f41f _dispatch_barrier_sync_f_slow_invoke + 54
2  libdispatch.dylib              0x044904d0 _dispatch_client_callout + 14
3  libdispatch.dylib              0x0447e726 _dispatch_main_queue_callback_4CF + 340
4  CoreFoundation                 0x040fb43e __CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__ + 14
5  CoreFoundation                 0x0403c5cb __CFRunLoopRun + 1963
6  CoreFoundation                 0x0403b9d3 CFRunLoopRunSpecific + 467
7  CoreFoundation                 0x0403b7eb CFRunLoopRunInMode + 123
8  Foundation                     0x03a71e35 -[NSRunLoop(NSRunLoop) runMode:beforeDate:] + 284
9  Foundation                     0x03a71cd5 -[NSRunLoop(NSRunLoop) runUntilDate:] + 88
10 Remind101-Tests                0x0cbb2c02 -[UTTestCase waitForBlockWithTimeout:] + 233
11 Remind101-Tests                0x0cbb2b14 -[UTTestCase waitForBlock] + 49
12 Remind101-Tests                0x0cbba55e -[UTAPITestCase sendRequestExpectingSuccess:] + 142
13 Remind101-Tests                0x0cb92832 -[UTMessageRequestTests testRequestCreatesFileEntities] + 166
14 CoreFoundation                 0x0408a91d __invoking___ + 29
15 CoreFoundation                 0x0408a82a -[NSInvocation invoke] + 362
16 XCTest                         0x20103c6c -[XCTestCase invokeTest] + 221
17 XCTest                         0x20103d7b -[XCTestCase performTest:] + 111
18 otest-shim-ios.dylib           0x0098fcc7 XCPerformTestWithSuppressedExpectedAssertionFailures + 172
19 otest-shim-ios.dylib           0x0098fc15 XCTestCase_performTest + 31
20 XCTest                         0x20104c48 -[XCTest run] + 82
21 XCTest                         0x201033e8 -[XCTestSuite performTest:] + 139
22 XCTest                         0x20104c48 -[XCTest run] + 82
23 XCTest                         0x201033e8 -[XCTestSuite performTest:] + 139
24 XCTest                         0x20104c48 -[XCTest run] + 82
25 XCTest                         0x201033e8 -[XCTestSuite performTest:] + 139
26 XCTest                         0x20104c48 -[XCTest run] + 82
27 XCTest                         0x201066ba +[XCTestProbe runTests:] + 183
28 Foundation                     0x03a4b5ec __NSFireDelayedPerform + 372
29 CoreFoundation                 0x04054ac6 __CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__ + 22
30 CoreFoundation                 0x040544ad __CFRunLoopDoTimer + 1181
31 CoreFoundation                 0x0403c538 __CFRunLoopRun + 1816
32 CoreFoundation                 0x0403b9d3 CFRunLoopRunSpecific + 467
33 CoreFoundation                 0x0403b7eb CFRunLoopRunInMode + 123
34 GraphicsServices               0x057495ee GSEventRunModal + 192
35 GraphicsServices               0x0574942b GSEventRun + 104
36 UIKit                          0x01e7ff9b UIApplicationMain + 1225
37 Remind101                      0x0008d184 main (main.m:16)
38 libdyld.dylib                  0x046c5701 start + 1

NSManagedObjectContext stream failed:

Thread : Crashed: NSManagedObjectContext Queue
0  libobjc.A.dylib                0x03e250be objc_msgSend + 26
1  CoreData                       0x0108ffe3 developerSubmittedBlockToNSManagedObjectContextPerform_privateasync + 83
2  libdispatch.dylib              0x044904d0 _dispatch_client_callout + 14
3  libdispatch.dylib              0x0447e047 _dispatch_queue_drain + 452
4  libdispatch.dylib              0x0447de42 _dispatch_queue_invoke + 128
5  libdispatch.dylib              0x0447ede2 _dispatch_root_queue_drain + 78
6  libdispatch.dylib              0x0447f127 _dispatch_worker_thread2 + 39
7  libsystem_pthread.dylib        0x047bfdab _pthread_wqthread + 336
8  libsystem_pthread.dylib        0x047c3cce start_wqthread + 30

, developerSubmittedBlockToNSManagedObjectContextPerform_privateasync objc_msgSend.

, - MyObjectManager.managedObjectContext , , , . , , , , .

NSManagedObjectContext::performBlock RestKit, , , , . , , . performBlockAndWait, , .

, . , , - , , .

+4
1

developerSubmittedBlockToNSManagedObjectContextPerform_privateasync:

  • .
  • _processRecentChanges:
  • .
  • ( )

NULL, , . , objc_msgSend, _processRecentChanges:.

-[NSManagedObjectContext _processRecentChanges:] , - . , RestKit , . , , - . . (, EXC_BAD_ACCESS ..), .

_processRecentChanges: , . - , , . , , .

0

Source: https://habr.com/ru/post/1546922/


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