xcode - 如何在 macOS 下模拟内存不足的情况？

Question

在开发和调试 macOS 应用时，有没有办法模拟系统范围的“内存不足”事件或通知？

iOS 模拟器有这样的功能，但我似乎无法找到 macOS 下的等效功能。

我有兴趣模拟低内存情况，以了解像 NSPurgeableData 和 IOSurface 这样的类如何处理被清除。

(除了编​​写一个不断分配内存的简单应用程序...)

Answer 1

macOS 上的工具用于模拟内存不足的情况，为 memory_Pressure(示例):

sudo memory_pressure -S -l critical

上面的命令模拟 (-S) 临界级别 (-l 临界) 的内存压力。

NAME
memory_pressure -- Tool to apply real or simulate memory pressure on the system.

SYNOPSIS
memory_pressure [-l level] | [-p percent_free] | [-S -l level]

OPTIONS
-l Apply real or simulate memory pressure (if specified alongside simulate argument) on the system till low memory notifications corresponding to are generated. Supported values are "warn" and "critical".

 -p <percent_free> Allocate memory till the available memory in the system
 is <percent_free> of total memory. If the percentage of available memory
 to total memory on the system drops, the tool will free memory till
 either the desired percentage is achieved or it runs out of memory to
 free.

 -S Simulate memory pressure on the system by placing it artificially for
 <sleep_seconds> duration at the "warn" or "critical" level.

 -s <sleep_seconds> Duration to wait before allocating or freeing memory
 if applying real pressure. In case of simulating memory pressure, this is
 the duration the system will be maintained at an artifical memory level.

DESCRIPTION
A tool to apply real or simulate memory pressure on the system

SEE ALSO
vm_stat(1)