如何避免iPhone应用中的泄漏？

Question

我正在获取事件崩溃日志：

2011-07-21 23:18:51.233 iFeel[87679:910b] *** __NSAutoreleaseNoPool(): Object 0x5fbdef0 of class NSURL autoreleased with no pool in place - just leaking
2011-07-21 23:18:51.233 iFeel[87679:910b] *** __NSAutoreleaseNoPool(): Object 0x1462e38 of class NSCFString autoreleased with no pool in place - just leaking
2011-07-21 23:18:51.233 iFeel[87679:910b] *** __NSAutoreleaseNoPool(): Object 0x1462e38 of class NSCFString autoreleased with no pool in place - just leaking
2011-07-21 23:18:51.233 iFeel[87679:910b] *** __NSAutoreleaseNoPool(): Object 0x5fb32b0 of class NSCFString autoreleased with no pool in place - just leaking
2011-07-21 23:18:51.235 iFeel[87679:910b] *** __NSAutoreleaseNoPool(): Object 0x5fc04e0 of class NSCFString autoreleased with no pool in place - just leaking
2011-07-21 23:18:51.235 iFeel[87679:910b] *** __NSAutoreleaseNoPool(): Object 0x5f98960 of class NSCFString autoreleased with no pool in place - just leaking
2011-07-21 23:18:51.235 iFeel[87679:910b] *** __NSAutoreleaseNoPool(): Object 0x5fa9c70 of class NSCFString autoreleased with no pool in place - just leaking
2011-07-21 23:18:51.550 iFeel[87679:910b] *** __NSAutoreleaseNoPool(): Object 0x5fbfbb0 of class NSHTTPURLResponse autoreleased with no pool in place - just leaking
2011-07-21 23:18:51.550 iFeel[87679:910b] *** __NSAutoreleaseNoPool(): Object 0x5fb5840 of class __NSCFData autoreleased with no pool in place - just leaking
2011-07-21 23:18:51.550 iFeel[87679:910b] *** __NSAutoreleaseNoPool(): Object 0x5fb1400 of class __NSArrayM autoreleased with no pool in place - just leaking
2011-07-21 23:18:51.551 iFeel[87679:910b] *** __NSAutoreleaseNoPool(): Object 0x5f83e70 of class NSCFString autoreleased with no pool in place - just leaking
2011-07-21 23:18:51.551 iFeel[87679:910b] *** __NSAutoreleaseNoPool(): Object 0x5fbd480 of class NSCFString autoreleased with no pool in place - just leaking
2011-07-21 23:18:51.551 iFeel[87679:910b] *** __NSAutoreleaseNoPool(): Object 0x5fb31b0 of class NSPathStore2 autoreleased with no pool in place - just leaking
2011-07-21 23:18:51.551 iFeel[87679:910b] *** __NSAutoreleaseNoPool(): Object 0x5fa9aa0 of class NSPathStore2 autoreleased with no pool in place - just leaking
2011-07-21 23:18:51.551 iFeel[87679:910b] *** __NSAutoreleaseNoPool(): Object 0x5fa6110 of class __NSArrayI autoreleased with no pool in place - just leaking
2011-07-21 23:18:51.552 iFeel[87679:910b] *** __NSAutoreleaseNoPool(): Object 0x5fb9700 of class NSCFString autoreleased with no pool in place - just leaking

有没有人能帮我避免崩溃？

Answer 1

很可能是因为您在没有自动释放池的线程上执行代码，所以才会看到这种情况。所有Apple的API都会大量使用自动释放池，所以在整个线程中使用一个自动释放池是很重要的。下面是一个这样的例子：

- (void)myThreadMethod:(id)anObject {
    NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
    NSLog(@"This is some objective-c code...");
    [pool drain];
}

水池排水口部分非常重要。如果没有这段代码，在线程生命周期内自动释放的所有对象都将被泄漏。

Answer 2

设置NSAutoreleasePool的实例。有关详细信息和示例，请查看NSAutoreleasePool Class Reference。

您可能还想浏览一下Memory Management Programming Guide，看看为什么设置它很重要，以及autorelease实际做了什么。

我还发现这篇文章的讨论很有帮助：How does the NSAutoreleasePool autorelease pool work?

Answer 3

来自苹果文档link

NSAutoreleasePool类用于支持Cocoa的引用计数内存管理系统。自动释放池存储在池本身耗尽时发送释放消息的对象。

重要提示:如果使用自动引用计数(ARC)，则不能直接使用自动释放池。相反，您可以使用@autoreleasepool块。例如，代替：

 NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init]; 
// Code benefitting from a local autorelease pool. 
[pool release];

你可以这样写：

 @autoreleasepool {
     // Code benefitting from a local autorelease pool. 
}

@autoreleasepool池块比直接使用NSAutoreleasePool的实例效率更高；即使不使用ARC，您也可以使用它们。