Swift implementation of function for measuring application launch time. Call it from start or end didFinishLaunchingWithOptions.

LaunchTimeMeasurer.swift

import UIKit

class LaunchTimeMeasurer {
    private let pid = ProcessInfo().processIdentifier
    private var currentTime = timeval(tv_sec: 0, tv_usec: 0)
    private var bootTime = timeval()
    private var size = MemoryLayout<kinfo_proc>.stride
    private var mib: [Int32]
    
    init() {
        mib = [CTL_KERN, KERN_PROC, KERN_PROC_PID, pid]
    }
    
    func processLaunchTime() -> Double {
        sysctl(&mib, u_int(mib.count), &bootTime, &size, nil, 0)
        gettimeofday(&currentTime, nil)
        
        return toSeconds(time: currentTime) - toSeconds(time: bootTime)
    }
    
    private func toSeconds(time: timeval) -> Double {
        let microsecondsInSecond = 1000000.0
        return Double(time.tv_sec) + Double(time.tv_usec) / microsecondsInSecond
    }
}

malloc: Heap corruption detected, free list is damaged at 0x60000138d090
*** Incorrect guard value: 5643587033499
(6555,0x10eb575c0) malloc: *** set a breakpoint in malloc_error_break to debug

I am getting the above error while executing the code.Can you please help to resolve this?

I'm having an issue implementing this code. After the sysctl call on line 15 it corrupts the stack and upon returning it gives me the following error: "error: memory read failed for 0x0". I stepped through the code and that line is where it happens. Up until that point I can see the stacktrace just fine, but as soon as that line executes it's gone. Even though I get valid values back from calling toSeconds: it just crashes the app. Any help you might be able to give me would be greatly appreciated!

I was able to figure out what was wrong, and it might help @RagulChandra too. sysctl takes a kinfo_proc, not a timeval. Using a timeval will still return the correct value, but causes memory corruption later on in your app's life cycle.

Here are the modifications that should be made to avoid memory corruption:

...
private var kp = kinfo_proc()  // kp instead of bootTime
...

func processLaunchTime() -> Double {
  sysctl(&mib, u_int(mib.count), &kp, &size, nil, 0)
  gettimeofday(&currentTime, nil)

  let bootTime = kp.kp_proc.p_un.__p_starttime  // this is a timeval struct

  return toSeconds(time: currentTime) - toSeconds(time: bootTime)
}