Xcode 4.2.1:NSThread 导致内存泄漏,使用 ARC
我在 Xcode 中进行的一个学校项目即将结束,但现在我遇到了一个小但非常烦人的问题:内存泄漏。泄漏已追溯到以下代码行:
@autoreleasepool {
[NSThread detachNewThreadSelector:@selector(updateThread) toTarget:self withObject:nil];
}
当我将其注释掉时,泄漏就消失了。显然,自动释放池中出了问题:我对这些仍然有点陌生(尤其是在使用 ARC 时),但是像 这个让我清楚地知道使用@autoreleasepool应该足够了。
由于某种原因,我的代码并非如此。我想我在这里遗漏了一些东西:如果有人可以就问题可能是什么提出一些想法,那么我们将不胜感激。只要告诉我是否必须发布更多代码,这不会成为问题:只是为了问题的可读性,我尝试将其限制为主要问题。
提前致谢!
编辑:
感谢您的第一反应!然而,问题仍然存在......我将发布更多代码来澄清一些事情。线程在 viewDidLoad 中启动:
/*
Everything mentioned here will be done after loading.
*/
- (void)viewDidLoad
{
// Do standard setup
[super viewDidLoad];
// Do any additional setup before loading the view from its nib.
self.title = @"Blog Manager";
// Activate edit mode
[tbvBlogList setEditing:YES animated:YES];
tbvBlogList.allowsSelectionDuringEditing = YES;
[NSThread detachNewThreadSelector:@selector(updateThread) toTarget:self withObject:nil];
UIImage *btnImage = [UIImage imageNamed:@"iPhone_General_Button_Add_Blog.png"];
UIButton *viewBtnAddBlog = [UIButton buttonWithType:UIButtonTypeCustom];
[viewBtnAddBlog setImage:btnImage forState:UIControlStateNormal];
viewBtnAddBlog.frame = CGRectMake(0, 0, 80, 36);
[viewBtnAddBlog addTarget:self action:@selector(addBlogByButton:) forControlEvents:UIControlEventTouchUpInside];
UIBarButtonItem *btnAddBlog = [[UIBarButtonItem alloc] initWithCustomView:viewBtnAddBlog];
btnAddBlog.tintColor = [UIColor clearColor];
self.navigationItem.rightBarButtonItem = btnAddBlog;
}
然后,用于线程的其他函数:
/*
Thread to update the progress bar with.
*/
- (void)updateThread
{
@autoreleasepool {
while(YES){
[self performSelectorOnMainThread:@selector(updateProgressBar) withObject:nil waitUntilDone:false];
[NSThread sleepForTimeInterval:0.1f];
}
}
}
/*
Updates the progress bar.
*/
- (void)updateProgressBar
{
pvProgress.progress = dProgress;
}
如果有什么值得一提的:我正在使用 Xcode 4.2.1。再次感谢您的支持!
I'm nearing the end of a school project with programming in Xcode, but right now I'm having a small yet extremely annoying issue: a memory leak. The leak has been traced down to the following line of code:
@autoreleasepool {
[NSThread detachNewThreadSelector:@selector(updateThread) toTarget:self withObject:nil];
}
When I comment this out, the leak is gone. Apparently something goes wrong in the autoreleasepool: I'm still a bit new on these (especially when using ARC), but threads like this one made it clear to me that using @autoreleasepool should be sufficient.
For some reason, this is not the case for my code. I guess I'm missing something here: if someone could give some ideas on what the issue could be, then that would be highly appreciated. Just tell me if I have to post more code, that won't be a problem: it's just for the readability of the question that I try to limit it to the main issue.
Thanks in advance!
EDIT:
Thank you for the first responses! The issue still persists however... I will post a bit more code to clear things up a bit. The thread is started in viewDidLoad:
/*
Everything mentioned here will be done after loading.
*/
- (void)viewDidLoad
{
// Do standard setup
[super viewDidLoad];
// Do any additional setup before loading the view from its nib.
self.title = @"Blog Manager";
// Activate edit mode
[tbvBlogList setEditing:YES animated:YES];
tbvBlogList.allowsSelectionDuringEditing = YES;
[NSThread detachNewThreadSelector:@selector(updateThread) toTarget:self withObject:nil];
UIImage *btnImage = [UIImage imageNamed:@"iPhone_General_Button_Add_Blog.png"];
UIButton *viewBtnAddBlog = [UIButton buttonWithType:UIButtonTypeCustom];
[viewBtnAddBlog setImage:btnImage forState:UIControlStateNormal];
viewBtnAddBlog.frame = CGRectMake(0, 0, 80, 36);
[viewBtnAddBlog addTarget:self action:@selector(addBlogByButton:) forControlEvents:UIControlEventTouchUpInside];
UIBarButtonItem *btnAddBlog = [[UIBarButtonItem alloc] initWithCustomView:viewBtnAddBlog];
btnAddBlog.tintColor = [UIColor clearColor];
self.navigationItem.rightBarButtonItem = btnAddBlog;
}
Then, the other functions that are used for the threading:
/*
Thread to update the progress bar with.
*/
- (void)updateThread
{
@autoreleasepool {
while(YES){
[self performSelectorOnMainThread:@selector(updateProgressBar) withObject:nil waitUntilDone:false];
[NSThread sleepForTimeInterval:0.1f];
}
}
}
/*
Updates the progress bar.
*/
- (void)updateProgressBar
{
pvProgress.progress = dProgress;
}
If it is anything worth mentioning: I'm using Xcode 4.2.1. Thanks again for the support!
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现在我只想拿石头砸自己。
我刚刚意识到“while”循环永远不会停止。当然,这意味着线程将继续运行,因此在应用程序完成之前内存不会被释放。
通过简单地添加一个在线程应该退出时设置为“NO”的布尔值,问题就得到了解决。各位:非常感谢你们帮我看这个问题。有时最大的问题有最小的解决方案......
Right now I just want to hit myself with a rock.
I just realized the "while"-loop never stops. Of course this means the thread will keep running, therefore the memory won't ever be released until the app finishes.
By simply adding a boolean that is set to "NO" when the thread should quit, the issue was solved. Everyone: thanks you very much for looking at this problem for me. Sometimes the biggest problems have the smallest solutions...
@autoreleasepool
块位于线程代码中(在本例中为updateThread
),而不是围绕线程的创建。The
@autoreleasepool
block goes in your thread code (updateThread
in this case), not around the creation of the thread.您没有在分离选择器的方法内创建自动释放池。每个线程选择器都需要自己的池。这样做:
You're not creating an autorelease pool inside the detached selector's method. Every thread selector needs its own pool. Do like this: