已在07/01/2019在Mojave 10.4.6的Xcode 11上进行了测试。
先前的所有答案均返回错误的结果。
这是如何获得苹果公司的奎因（Quinn）“爱斯基摩人”（The Eskimo！）所写的期望值的方法。
它使用phys_footprintvar中的var Darwin > Mach > task_info并与Xcode的Debug导航器中的内存量表中的值紧密匹配。
返回的值以字节为单位。
https://forums.developer.apple.com/thread/105088#357415
原始代码如下。
func memoryFootprint() -> mach_vm_size_t? {
// The `TASK_VM_INFO_COUNT` and `TASK_VM_INFO_REV1_COUNT` macros are too
// complex for the Swift C importer, so we have to define them ourselves.
let TASK_VM_INFO_COUNT = mach_msg_type_number_t(MemoryLayout<task_vm_info_data_t>.size / MemoryLayout<integer_t>.size)
let TASK_VM_INFO_REV1_COUNT = mach_msg_type_number_t(MemoryLayout.offset(of: \task_vm_info_data_t.min_address)! / MemoryLayout<integer_t>.size)
var info = task_vm_info_data_t()
var count = TASK_VM_INFO_COUNT
let kr = withUnsafeMutablePointer(to: &info) { infoPtr in
infoPtr.withMemoryRebound(to: integer_t.self, capacity: Int(count)) { intPtr in
task_info(mach_task_self_, task_flavor_t(TASK_VM_INFO), intPtr, &count)
}
}
guard
kr == KERN_SUCCESS,
count >= TASK_VM_INFO_REV1_COUNT
else { return nil }
return info.phys_footprint
}
稍加修改即可创建一个类级别的Swift方法集，从而可以轻松返回实际字节并以MB为单位显示格式化输出。我将其用作自动化UITest套件的一部分，以记录在同一测试的多次迭代之前和之后使用的内存，以查看是否有任何潜在的泄漏或需要我们研究的分配。
// Created by Alex Zavatone on 8/1/19.
//
class Memory: NSObject {
// From Quinn the Eskimo at Apple.
// https://forums.developer.apple.com/thread/105088#357415
class func memoryFootprint() -> Float? {
// The `TASK_VM_INFO_COUNT` and `TASK_VM_INFO_REV1_COUNT` macros are too
// complex for the Swift C importer, so we have to define them ourselves.
let TASK_VM_INFO_COUNT = mach_msg_type_number_t(MemoryLayout<task_vm_info_data_t>.size / MemoryLayout<integer_t>.size)
let TASK_VM_INFO_REV1_COUNT = mach_msg_type_number_t(MemoryLayout.offset(of: \task_vm_info_data_t.min_address)! / MemoryLayout<integer_t>.size)
var info = task_vm_info_data_t()
var count = TASK_VM_INFO_COUNT
let kr = withUnsafeMutablePointer(to: &info) { infoPtr in
infoPtr.withMemoryRebound(to: integer_t.self, capacity: Int(count)) { intPtr in
task_info(mach_task_self_, task_flavor_t(TASK_VM_INFO), intPtr, &count)
}
}
guard
kr == KERN_SUCCESS,
count >= TASK_VM_INFO_REV1_COUNT
else { return nil }
let usedBytes = Float(info.phys_footprint)
return usedBytes
}
class func formattedMemoryFootprint() -> String
{
let usedBytes: UInt64? = UInt64(self.memoryFootprint() ?? 0)
let usedMB = Double(usedBytes ?? 0) / 1024 / 1024
let usedMBAsString: String = "\(usedMB)MB"
return usedMBAsString
}
}
请享用！
注意：进取的编码人员可能想要向该类添加静态格式化程序，以便usedMBAsString仅返回2个有效的小数位。