Chapter 1 Analyze performance issues

Use Unity Profiler get data

• Connection on device profile, The data are not entirely accurate
  • because Development Mode and connection Unity profile Lead to CPU The load increases and the memory increases greatly . If you run in some large projects , It will cause memory overflow , The script does not run , Physical effects stop update , etc.
  • To avoid some of the above , We're going to use benchmarking( Benchmarking analysis ): At some switching points , Pay attention to a period of time when the performance becomes significantly worse .
  • Editor Medium Profile The data is not reliable , It needs to be used in the real machine .

Profile Remote connection iOS

Be careful ： Connect iOS Equipment time ,Unity Must be in Mac Machine running

1. When the packaging Development Build and Autoconnect Profiler tick
2. The computer and mobile phone are connected to the same local network WiFi
3. use usb Connect your phone to mac The computer
4. pack
5. stay Unity Open in Profiler, And then choose iOS equipment

If there is still a problem with the connection , Check here ：https:/​/​docs.​unity3d.com/​Manual/TroubleShootingIPhone.​html

Profile Remote connection Android

and iOS be similar .
If there's a problem with the connection , Check here ：[https:/​/​docs.​unity3d.com/​Manual/TroubleShootingAndroid. ​html](https:/​/​docs.​unity3d.com/​Manual/TroubleShootingAndroid. ​html)

Deep Profile

You can see almost all the calling methods . But it costs a lot .

Allocation Callstack （2019 above ）

Activate Call Stacks After button , In an open DeepProfile Under the circumstances .Profiler It will also collect more memory allocation problems .
And then through Show Related Objects Button , We can see the call stack .

Performance analysis Check List

1. Verify that the target script appears in the scene
2. Verify that the target script appears correctly
3. Verify the correct sequence of events
4. Minimize ongoing code changes
5. Minimize internal interference
6. Minimize external interference

Custom script analysis

Use stopwatch Class to create a timing tool ：

using System.Diagnostics;
public class CustomTimer : IDisposable {
    
private string _timerName;
private int _numTests;
private Stopwatch _watch;
// give the timer a name, and a count of the
// number of tests we're running
public CustomTimer(string timerName, int numTests) {
    
	_timerName = timerName;
	_numTests = numTests;
	
	if (_numTests <= 0) {
    
		_numTests = 1;
	}
	_watch = Stopwatch.StartNew();
}
	// automatically called when the 'using()' block ends
	public void Dispose() {
    
		_watch.Stop();
		float ms = _watch.ElapsedMilliseconds;
		UnityEngine.Debug.Log(string.Format("{0} finished: {1:0.00} " +
		"milliseconds total, {2:0.000000} milliseconds per-test " +
		"for {3} tests", _timerName, ms, ms / _numTests, _numTests));
	}
}

Examples of use ：

const int numTests = 1000;
using (new CustomTimer("My Test", numTests)) {
    
	for(int i = 0; i < numTests; ++i) {
    
		TestFunction();
	}
} //  After execution timer's Dispose()  Will be called