1、对象什么时候dealloc？
当对象的引用计数减为0时候。
2、dealloc发生在哪个线程？
#import "ViewController.h"
@interface classTest : NSObject
@end
@implementation classTest
- (void)dealloc{
NSThread *currentThread = [NSThread currentThread];
NSLog(@"object dealloc at thread: %@",currentThread);
}
@end
@interface ViewController ()
@property(nonatomic,strong) NSMutableArray *tArr;
@end
@implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
[self dealloc_test];
}
-(void)dealloc_test{
_tArr = [NSMutableArray array];
NSThread *currentThread = [NSThread currentThread];
NSLog(@"viewDidLoad at thread: %@",currentThread);
classTest *t = [[classTest alloc]init];
[_tArr addObject:t];
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
[[NSThread currentThread] setName:@"DISPATCH_QUEUE_XXX"];
[self.tArr removeAllObjects];
});
}
复制代码执行结果：
2019-07-11 xxtest[29479:1344125] viewDidLoad at thread: <NSThread: 0x6000014f5300>{number = 1, name = main}
2019-07-11 xxtest[29479:1344218] object dealloc at thread: <NSThread: 0x6000014fe700>{number = 3, name = DISPATCH_QUEUE_XXX}
复制代码dealloc并不总是在主线程中被调用，，其调用线程为最后一个调用release方法的线程。 也就是说,dealloc方法有可能在任何线程被调用。