我目前正在努力與我的應用程序,藐視(我的)邏輯核心數據問題。我確信我做錯了什麼,但看不到。iPhone核心數據 - 獲取的管理對象不在設備上發佈(罰款在模擬器上)
我在我的核心數據實體上做了一個基本的executeFetchRequest,但是返回的管理對象數組似乎從未在iPhone上運行時發佈,在模擬器下它的工作方式與預期完全一樣。
儘管使用NSAutoreleasePool來確保內存佔用最小化。我也檢查過儀器,沒有泄漏,只是不斷增加內存分配('[NSManagedObject(_PFDynamicAccessorsAndPropertySupport)allocWithEntity:]')。在我的實際應用程序中,這最終導致了didReceiveMemoryWarning調用。
我已經制作了一個最小化的程序,它重現了下面的問題。我曾嘗試過各種各樣的事情,比如在排出泳池之前斷開所有物體,但沒有任何快樂。如果我提供了一個NSError指針,則返回錯誤。沒有後臺線程正在運行。
#import <mach/mach.h>
#import <mach/mach_host.h>
+(natural_t) get_free_memory {
mach_port_t host_port;
mach_msg_type_number_t host_size;
vm_size_t pagesize;
host_port = mach_host_self();
host_size = sizeof(vm_statistics_data_t)/sizeof(integer_t);
host_page_size(host_port, &pagesize);
vm_statistics_data_t vm_stat;
if (host_statistics(host_port, HOST_VM_INFO, (host_info_t)&vm_stat, &host_size) != KERN_SUCCESS) {
NSLog(@"Failed to fetch vm statistics");
return 0;
}
/* Stats in bytes */
natural_t mem_free = vm_stat.free_count * pagesize;
return mem_free;
}
- (void)viewDidLoad
{
[super viewDidLoad];
// Set up the edit and add buttons.
self.navigationItem.leftBarButtonItem = self.editButtonItem;
UIBarButtonItem *addButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:self action:@selector(insertNewObject)];
self.navigationItem.rightBarButtonItem = addButton;
[addButton release];
// Obtain the Managed Object Context
NSManagedObjectContext *context = [(id)[[UIApplication sharedApplication] delegate] managedObjectContext];
// Check the free memory before we start
NSLog(@"INITIAL FREEMEM: %d", [RootViewController get_free_memory]);
// Loop around a few times
for(int i=0; i<20; i++) {
// Create an autorelease pool just for this loop
NSAutoreleasePool *looppool = [[NSAutoreleasePool alloc] init];
// Check the free memory each time around the loop
NSLog(@"FREEMEM: %d", [RootViewController get_free_memory]);
// Create a minimal request
NSEntityDescription *entityDescription = [NSEntityDescription
entityForName:@"TestEntity" inManagedObjectContext:context];
NSFetchRequest *request = [[NSFetchRequest alloc] init];
[request setEntity:entityDescription];
// Perform the fetch
NSArray *array = [context executeFetchRequest:request error:nil];
[request release];
// Drain the pool - should release the fetched managed objects?
[looppool drain];
}
// Check the free menory at the end
NSLog(@"FINAL FREEMEM: %d", [RootViewController get_free_memory]);
}
當我運行在模擬器上我得到下面的輸出(這看起來合理的,我):
2011-06-06 09:50:28.123 renniksoft[937:207] INITIAL FREEMEM: 14782464
2011-06-06 09:50:28.128 renniksoft[937:207] FREEMEM: 14807040
2011-06-06 09:50:28.135 renniksoft[937:207] FREEMEM: 14831616
2011-06-06 09:50:28.139 renniksoft[937:207] FREEMEM: 14852096
2011-06-06 09:50:28.142 renniksoft[937:207] FREEMEM: 14872576
2011-06-06 09:50:28.146 renniksoft[937:207] FREEMEM: 14897152
2011-06-06 09:50:28.149 renniksoft[937:207] FREEMEM: 14917632
2011-06-06 09:50:28.153 renniksoft[937:207] FREEMEM: 14938112
2011-06-06 09:50:28.158 renniksoft[937:207] FREEMEM: 14962688
2011-06-06 09:50:28.161 renniksoft[937:207] FREEMEM: 14983168
2011-06-06 09:50:28.165 renniksoft[937:207] FREEMEM: 14741504
2011-06-06 09:50:28.168 renniksoft[937:207] FREEMEM: 14770176
2011-06-06 09:50:28.174 renniksoft[937:207] FREEMEM: 14790656
2011-06-06 09:50:28.177 renniksoft[937:207] FREEMEM: 14811136
2011-06-06 09:50:28.182 renniksoft[937:207] FREEMEM: 14831616
2011-06-06 09:50:28.186 renniksoft[937:207] FREEMEM: 14589952
2011-06-06 09:50:28.189 renniksoft[937:207] FREEMEM: 14610432
2011-06-06 09:50:28.192 renniksoft[937:207] FREEMEM: 14630912
2011-06-06 09:50:28.194 renniksoft[937:207] FREEMEM: 14651392
2011-06-06 09:50:28.197 renniksoft[937:207] FREEMEM: 14671872
2011-06-06 09:50:28.200 renniksoft[937:207] FREEMEM: 14692352
2011-06-06 09:50:28.203 renniksoft[937:207] FINAL FREEMEM: 14716928
然而,當我在實際的iPhone 4運行(4.3.3 )我得到以下結果:
2011-06-06 09:55:54.341 renniksoft[4727:707] INITIAL FREEMEM: 267927552
2011-06-06 09:55:54.348 renniksoft[4727:707] FREEMEM: 267952128
2011-06-06 09:55:54.702 renniksoft[4727:707] FREEMEM: 265818112
2011-06-06 09:55:55.214 renniksoft[4727:707] FREEMEM: 265355264
2011-06-06 09:55:55.714 renniksoft[4727:707] FREEMEM: 264892416
2011-06-06 09:55:56.215 renniksoft[4727:707] FREEMEM: 264441856
2011-06-06 09:55:56.713 renniksoft[4727:707] FREEMEM: 263979008
2011-06-06 09:55:57.226 renniksoft[4727:707] FREEMEM: 264089600
2011-06-06 09:55:57.721 renniksoft[4727:707] FREEMEM: 263630848
2011-06-06 09:55:58.226 renniksoft[4727:707] FREEMEM: 263168000
2011-06-06 09:55:58.726 renniksoft[4727:707] FREEMEM: 262705152
2011-06-06 09:55:59.242 renniksoft[4727:707] FREEMEM: 262852608
2011-06-06 09:55:59.737 renniksoft[4727:707] FREEMEM: 262389760
2011-06-06 09:56:00.243 renniksoft[4727:707] FREEMEM: 261931008
2011-06-06 09:56:00.751 renniksoft[4727:707] FREEMEM: 261992448
2011-06-06 09:56:01.280 renniksoft[4727:707] FREEMEM: 261574656
2011-06-06 09:56:01.774 renniksoft[4727:707] FREEMEM: 261148672
2011-06-06 09:56:02.290 renniksoft[4727:707] FREEMEM: 260755456
2011-06-06 09:56:02.820 renniksoft[4727:707] FREEMEM: 260837376
2011-06-06 09:56:03.334 renniksoft[4727:707] FREEMEM: 260395008
2011-06-06 09:56:03.825 renniksoft[4727:707] FREEMEM: 259932160
2011-06-06 09:56:04.346 renniksoft[4727:707] FINAL FREEMEM: 259555328
可用內存的數量每次循環都會減少,與獲取的託管對象成比例如果我獲取的對象數量是對象的兩倍,那麼可用內存會減少一倍 - 所以我相當確信它是未被釋放的託管對象。
請注意,正在提取的實體是非常基本的,只有兩個屬性,一個字符串和一個16位整數。在上面的例子中有1000個被抓取。我用來生成它們的代碼如下:
// Create test entities
for(int i=0; i<1000; i++) {
id entity = [NSEntityDescription insertNewObjectForEntityForName:@"TestEntity" inManagedObjectContext:context];
[entity setValue:[NSString stringWithFormat:@"%d",i] forKey:@"name"];
[entity setValue:[NSNumber numberWithInt:i] forKey:@"value"];
}
if (![context save:nil]) {
NSLog(@"Couldn't save");
}
如果任何人都可以向我解釋發生了什麼,我會非常感激!這個問題是唯一一個阻止我的應用程序發佈。它在模擬器上運行非常漂亮!
請讓我知道,如果有任何更多的信息,我可以提供。
只是好奇,是否有人設法使用上述代碼重現此問題,還是隻是我? – cliveski 2011-06-07 13:28:15