Swift：macのCPU使用率を取得する

#ソースと使用例

ソース

import Darwin

public class CPU {
    
    private let loadInfoCount: mach_msg_type_number_t!
    private let machHost = mach_host_self()
    private var loadPrevious = host_cpu_load_info()
    
    init() {
        loadInfoCount = UInt32(MemoryLayout<host_cpu_load_info_data_t>.size / MemoryLayout<integer_t>.size)
    }
    
    private func hostCPULoadInfo() -> host_cpu_load_info {
        var size: mach_msg_type_number_t = loadInfoCount
        let hostInfo = host_cpu_load_info_t.allocate(capacity: 1)
        
        let _ = hostInfo.withMemoryRebound(to: integer_t.self, capacity: Int(size)) { (pointer) -> kern_return_t in
            return host_statistics(machHost, HOST_CPU_LOAD_INFO, pointer, &size)
        }
        let data = hostInfo.move()
        hostInfo.deallocate()
        
        return data
    }
    
    public func usageCPU() -> (system: Double, user: Double, idle: Double) {
        let load = hostCPULoadInfo()
        let userDiff = Double(load.cpu_ticks.0 - loadPrevious.cpu_ticks.0)
        let sysDiff  = Double(load.cpu_ticks.1 - loadPrevious.cpu_ticks.1)
        let idleDiff = Double(load.cpu_ticks.2 - loadPrevious.cpu_ticks.2)
        let niceDiff = Double(load.cpu_ticks.3 - loadPrevious.cpu_ticks.3)
        loadPrevious = load
        let totalTicks = sysDiff + userDiff + idleDiff + niceDiff
        let sys  = 100.0 * sysDiff / totalTicks
        let user = 100.0 * userDiff / totalTicks
        let idle = 100.0 * idleDiff / totalTicks
        return (sys, user, idle)
    }
    
}

使用例

let cpu = CPU()
var timer = Timer.scheduledTimer(withTimeInterval: 3.0, repeats: true) { (t) in
    let res = cpu.usageCPU()
    Swift.print("システム: \(res.system)")
    Swift.print("ユーザ: \(res.user)")
    Swift.print("アイドル: \(res.idle)")
    Swift.print("CPU使用率: \(round(10.0 * (res.system + res.user)) / 10.0)\n")
}

#参考
beltex/SystemKit
SwiftでアプリのCPU使用率とメモリ使用量を取得する