iOS低内存崩溃，但内存使用率非常低

This has been annoying me for a long time. My app runs taking up about 2.74MB of memory. That's fine. But then when it creates a UIWebView it goes up to around 5.87MB and proceeds to crash. Those are the values given under Live Bytes in Instruments while running on my 1st gen iPad.

很长一段时间这让我烦恼。我的应用程序运行占用大约2.74MB的内存。没关系。但是当它创建一个UIWebView时，它会上升到大约5.87MB并继续崩溃。这些是在我的第一代iPad上运行时在仪器中的Live Bytes下给出的值。

There is no crash log that I can find. The following is from the console:

我找不到崩溃日志。以下内容来自控制台：

MyApp[1205] <Warning>: Received memory warning. Level=1
MyApp[1205] <Warning>: applicationDidReceiveMemoryWarning
SpringBoard[30] <Warning>: Received memory warning. Level=1
MobileMail[1199] <Warning>: Received memory warning. Level=1
configd[26] <Notice>: jetsam: kernel memory event (95), free: 428, active: 1853, inactive: 1011, purgeable: 338, wired: 15122
configd[26] <Notice>: jetsam: kernel termination snapshot being created
com.apple.launchd[1] <Notice>: (UIKitApplication:com.apple.mobilemail[0x8966]) Exited: Killed: 9
com.apple.launchd[1] <Notice>: (UIKitApplication:com.MyApp.MyApp[0xdd4f]) Exited: Killed: 9
SpringBoard[30] <Warning>: Application 'Mail' exited abnormally with signal 9: Killed: 9
kernel[0] <Debug>: launchd[1207] Builtin profile: MobileMail (sandbox)
SpringBoard[30] <Warning>: Application 'MyApp' exited abnormally with signal 9: Killed: 9
configd[26] <Debug>: CaptiveNetworkSupport:UIAllowedNotifyCallback:70 uiallowed: false
ReportCrash[1206] <Error>: libMobileGestalt loadBasebandMobileEquipmentInfo: CommCenter error: 1:45
ReportCrash[1206] <Error>: libMobileGestalt copyInternationalMobileEquipmentIdentity: Could not get mobile equipment info dictionary
ReportCrash[1206] <Error>: Saved crashreport to /Library/Logs/CrashReporter/LowMemory-2011-05-12-160645.plist using uid: 0 gid: 0, synthetic_euid: 0 egid: 0

I have removed all calls to imageNamed, changed autoreleased stuff to alloc/release. But I cannot work out why this is happening and it's driving me insane.

我已经删除了对imageNamed的所有调用，将自动释放的内容更改为alloc / release。但我无法弄清楚为什么会发生这种情况，这让我感到疯狂。

Thanks for any help!

谢谢你的帮助！

3 个解决方案

#1

You are almost certainly using a lot more memory than you think.

你几乎肯定会使用比你想象的更多的内存。

It's not obvious what you have to do to see what your app is really using, but once you do it a couple times, you'll remember.

你必须要做什么才能看到你的应用程序真正使用的是什么，但是一旦你做了几次，你就会记得。

1. Run with the Allocations performance tool.
2. 使用Allocations性能工具运行。
3. Click the VM Tracker "row" under "Allocations" (in the screenshot)
4. 单击“Allocations”下的VM Tracker“行”（在屏幕截图中）
5. Click "Snapshot Automatically"
6. 点击“自动快照”

Then you will see your Dirty memory (currently 20.34MB in my screenshot).

然后你会看到你的脏内存（我的截图中目前为20.34MB）。

This should give you a much better picture of why your app is getting quit. You probably hav some large leaking happening.

这可以让您更好地了解您的应用程序退出的原因。你可能发生了一些大的泄漏事件。

good luck!

祝你好运！

#2

I have two things to add that may help:

我有两件事要补充：

1. As mentioned in a previous answer , the bitmat of a UIImage is not considered in amount of memory Leaks tells you your app is using! so you may have a lot of UIImages that are using a lot of memory buy not showing in the total. My recommendation is to use Allocations to check out the number of UIImage objects created and destroyed while your app runs.
2. 正如之前的回答中所提到的，UIImage的bitmat不考虑内存量泄漏告诉你的应用程序正在使用！所以你可能有很多UIImages使用大量的内存购买没有显示在总数中。我的建议是使用Allocations来检查应用程序运行时创建和销毁的UIImage对象的数量。

3. As mentioned in this answer use the following code

   如本答案中所述，请使用以下代码

   -(void) report_memory {
       struct task_basic_info info;
       mach_msg_type_number_t size = sizeof(info);
       kern_return_t kerr = task_info(mach_task_self(),
                                      TASK_BASIC_INFO,
                                      (task_info_t)&info,
                                      &size);
       if( kerr == KERN_SUCCESS ) {
           NSLog(@"Memory in use (in bytes): %u", info.resident_size);
       } else {
           NSLog(@"Error with task_info(): %s", mach_error_string(kerr));
       }
   }
   

to see the amount of memory the operating system has assigned your app. That is more accurate number on the memory you app is using. (You will need to #import "mach/mach.h")

查看操作系统为您的应用分配的内存量。这是您应用正在使用的内存上更准确的数字。 （你需要#import“mach / mach.h”）

cheers!

干杯！

#3

You press that menu button 2 times fast you will see the app click the x for all the apps then open the ones you need.

您快速按下该菜单按钮2次，您将看到应用程序单击所有应用程序的x，然后打开您需要的应​​用程序。