在ARC下，是否仍建议为循环创建@autoreleasepool? [英] Under ARC, is it still advisable to create an @autoreleasepool for loops?

问题描述

假设我有一个循环，该循环返回一堆自动释放的NSData对象...

Let's say that I have a loop that returns a bunch of autoreleased NSData objects...

NSData* bigData = ...
while(some condition) {
    NSData* smallData = [bigData subdataWithRange:...];
    //process smallData
}

在ARC下，我是否还应该在while条件周围包裹一个@autoreleasepool?

Under ARC, should I still wrap an @autoreleasepool around the while condition?

NSData* bigData = ...
@autoreleasepool {
    while(some condition) {
        NSData* smallData = [bigData subdataWithRange:...];
        //process smallData
    }
}

我问的原因是我看到了我的NSData对象通过屋顶的仪器中的动态分配计数，这些对象调用dataWith...方法而不是initWith...方法.当我使用initWith...时，生活分配的数量要少得多.

The reason why I'm asking is I see the living allocation count in instruments going through the roof for my NSData objects that invoke a dataWith... method as opposed to an initWith... method. When I use initWith..., the living allocation count is much, much less.

是否最好尽可能使用initWith...方法?

Is it better to prefer the initWith... methods whenever possible?

推荐答案

是的，在紧密循环中使用便捷方法时，仍应使用自动释放池.所有旧的内存管理规则仍然适用于ARC，编译器只是为您注入RR.查看真棒Mike Ash的精彩文章！

Yes you should still use autorelease pools when using convenience methods in a tight loop. All the old memory management rules still apply under ARC, the compiler is merely injecting RRs for you. Checkout the great post by the awesome Mike Ash!

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