得到答案后编辑:
- 实际上没有内存泄漏。添加到NSInvocationOperation的对象将保留并按预期释放。
为什么在我向NSInvocationOperation添加一个对象后,它会被保留, 后该操作完成后再次保留?
我如何防止内存泄漏?
下来是我的示例代码。 如果那么多代码让你烦恼,我道歉,但我只是想确保我没有错过任何东西。 此外,NSLogs旁边的注释显示其输出。
我的整个AppDelegate.m:
//
// AppDelegate.m
// BRISI
//
// Created by Aleksa Topic on 2/22/12.
// Copyright (c) 2012 __MyCompanyName__. All rights reserved.
//
#import "AppDelegate.h"
@implementation AppDelegate
@synthesize window = _window;
- (void)dealloc
{
[_window release];
[super dealloc];
}
- (BOOL)application:(UIApplication *)application
didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
NSObject *a = [[NSObject alloc] init];
NSLog(@"a1: %d", a.retainCount); // a1: 1
NSOperationQueue *operationQueue = [[NSOperationQueue alloc] init];
NSInvocationOperation *operation = [[NSInvocationOperation alloc]
initWithTarget:self
selector:@selector(s:)
object:a];
NSLog(@"a2: %d", a.retainCount); // a2: 2
[a release];
NSLog(@"a3: %d", a.retainCount); // a3: 1
[operationQueue addOperation:operation];
[operation release];
NSLog(@"a4: %d", a.retainCount); // a4: 1
NSLog(@"oper1: %@", operation); // oper1: <NSInvocationOperation: 0x6a3f7d0>
NSLog(@"a5: %d", a.retainCount); // a5: 1
NSLog(@"a5: %d", a.retainCount); // a5: 1
NSLog(@"a5: %d", a.retainCount); // a5: 1
NSLog(@"a5: %d", a.retainCount); // a5: 2
NSLog(@"a5: %d", a.retainCount); // a5: 2
NSLog(@"a5: %d", a.retainCount); // a5: 2
NSLog(@"a5: %d", a.retainCount); // a5: 2
NSLog(@"a5: %d", a.retainCount); // a5: 2
// And here I get: "Thread 1: Program received signal: "EXC_BADACCESS"."
NSLog(@"oper2: %@", operation);
self.window = [[[UIWindow alloc]
initWithFrame:[[UIScreen mainScreen] bounds]] autorelease];
// Override point for customization after application launch.
self.window.backgroundColor = [UIColor whiteColor];
[self.window makeKeyAndVisible];
return YES;
}
- (void)s:(NSArray *)a
{
NSLog(@"a (s:): %d", a.retainCount); // a (s:): 1
NSLog(@"a (s:): %d", a.retainCount); // a (s:): 1
NSLog(@"a (s:): %d", a.retainCount); // a (s:): 1
}
@end
如果你想比较,这里是输出:
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This GDB was configured as "x86_64-apple-darwin".sharedlibrary apply-load-rules all
Attaching to process 7927.
2012-03-06 16:19:20.712 BRISI[7927:207] a1: 1
2012-03-06 16:19:20.715 BRISI[7927:207] a2: 2
2012-03-06 16:19:20.715 BRISI[7927:207] a3: 1
2012-03-06 16:19:20.716 BRISI[7927:207] a4: 1
2012-03-06 16:19:20.717 BRISI[7927:207] oper1: <NSInvocationOperation: 0x6858da0>
2012-03-06 16:19:20.717 BRISI[7927:1e03] a (s:): 1
2012-03-06 16:19:20.717 BRISI[7927:207] a5: 1
2012-03-06 16:19:20.718 BRISI[7927:1e03] a (s:): 1
2012-03-06 16:19:20.718 BRISI[7927:207] a5: 1
2012-03-06 16:19:20.718 BRISI[7927:1e03] a (s:): 1
2012-03-06 16:19:20.719 BRISI[7927:207] a5: 1
2012-03-06 16:19:20.719 BRISI[7927:207] a5: 2
2012-03-06 16:19:20.720 BRISI[7927:207] a5: 2
2012-03-06 16:19:20.720 BRISI[7927:207] a5: 2
2012-03-06 16:19:20.721 BRISI[7927:207] a5: 2
2012-03-06 16:19:20.721 BRISI[7927:207] a5: 2
Current language: auto; currently objective-c
(gdb)
答案 0 :(得分:0)
每当我处理棘手的保留/释放操作集时,我都要确保覆盖适当的方法:
@interface RetainCountChecker : NSObject
@end
@implementation RetainCountChecker
-(oneway void)release{
[super release];
NSLog(@"release - retainCount = %d", [self retainCount]);
}
-(id)retain{
id result = [super retain];
NSLog(@"retain - retainCount = %d", [self retainCount]);
return result;
}
-(void)dealloc{
[super dealloc];
}
@end
在retain,release和dealloc方法中放置断点可以让您查看每个方法的调用时间和方式。 在您的情况下,NSInvocationOperation是自动释放内部NSInvocation对象。在
中包装有问题的代码@autorelease{
}
block将在-application:didFinishLaunchingWithOptions:方法返回之前释放“a”。