iOS 上的活动监视器中的实时字节与实内存 [英] Live Bytes vs Real Memory in Activity Monitor on iOS

问题描述

我正在开发一个 iOS 应用程序，该应用程序将创建许多小对象和浮点数，并试图了解它消耗了多少内存.

I'm working on an iOS app that will create a lot of small objects and floats, and trying to get an idea for how much memory usage it's consuming.

当我运行Allocations"工具时，它说我有大约 2MB 的Live Bytes"，当我在应用程序中移动时，这个数字大致保持不变(当应用程序繁忙时，峰值高达 3MB 左右，但是然后回落到 2MB).

When I run the "Allocations" instrument, it says I have about 2MB of "Live Bytes", and the figure stays roughly constant as I move through the app (spikes up to 3MB or so when the App is busy, but then drops back down to 2MB).

但是当我运行Activity Monitor"工具时，我的应用程序的真实内存"在它完成启动后是 25MB，并且在我的 CALayer 内发生绘图时迅速增长.不到一分钟，它就超过了 100MB.

But when I run the "Activity Monitory" instrument, my app's "Real Memory" is 25MB once it finishes launching, and grows rapidly whenever drawing occurs inside my CALayer. In less than a minute, it goes over 100MB.

为什么Live Bytes"显示为 2MB，而Real Memory"显示为 100MB?

Why would "Live Bytes" show 2MB, but "Real Memory" shows 100MB?

我的 CALayer 正在绘制 吨 的路径，它在几秒钟内将 CPU 固定在 100% 以完成单个绘制操作，并将所有这些点从 NSData 对象加载到CGPoint 值，然后再次释放它们(NSData 对象是所绘制点的压缩版本，存储从一个点到下一个点的增量，所以我将它保存在 RAM 中，但不保存实际的 CGPoints).

My CALayer is drawing tons of paths, it pegs the CPU at 100% for a few seconds just to finish a single draw operation, and it's loading all of these points out of an NSData object into CGPoint values, then deallocing them again (The NSData object is a compressed version of the points being drawn, storing deltas from one point to the next, so I keep it in RAM but don't keep the actual CGPoints).

它还将绘制结果缓存在 UIImage 中，并将这些结果保存在一个先进先出数组中，该数组不会增长到超过 500KB.

It also caches the result of the drawing in a UIImage, and these are kept in a first-in-first-out array that won't grow to more than about 500KB.

推荐答案

原来我的问题是 NSZombieEnabled.

在 Edit Scheme > Run > Arguments > Environment Variables 中禁用它解决了额外的内存使用.

Disabling that in Edit Scheme > Run > Arguments > Environment Variables solved the extra memory use.

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