gistfile1.txt

/// Gets current CPU usage percentage for the current app's threads
/// Returns a value between 0.0 and 100.0 representing CPU utilization
/// Uses thread-specific CPU usage tracking for accurate app performance metrics
func getCPUUsage() -> Double {
    var totalUsageOfCPU = 0.0
    var threadsList = UnsafeMutablePointer(mutating: [thread_act_t]())
    var threadsCount = mach_msg_type_number_t(0)
    let threadsResult = withUnsafeMutablePointer(to: &threadsList) {
        $0.withMemoryRebound(to: thread_act_array_t?.self, capacity: 1) {
            task_threads(mach_task_self_, $0, &threadsCount)
        }
    }

    if threadsResult == KERN_SUCCESS {
        for index in 0 ..< threadsCount {
            var threadInfo = thread_basic_info()
            var threadInfoCount = mach_msg_type_number_t(THREAD_INFO_MAX)
            let infoResult = withUnsafeMutablePointer(to: &threadInfo) {
                $0.withMemoryRebound(to: integer_t.self, capacity: 1) {
                    thread_info(threadsList[Int(index)], thread_flavor_t(THREAD_BASIC_INFO), $0, &threadInfoCount)
                }
            }

            guard infoResult == KERN_SUCCESS else {
                break
            }

            let threadBasicInfo = threadInfo as thread_basic_info
            if threadBasicInfo.flags & TH_FLAGS_IDLE == 0 {
                totalUsageOfCPU = (totalUsageOfCPU + (Double(threadBasicInfo.cpu_usage) / Double(TH_USAGE_SCALE)))
            }
        }
    }

    vm_deallocate(mach_task_self_, vm_address_t(UInt(bitPattern: threadsList)), vm_size_t(Int(threadsCount) * MemoryLayout<thread_t>.stride))
    let cpuPercentage = totalUsageOfCPU * 100.0
    return cpuPercentage
}