Last active
December 6, 2021 09:22
-
-
Save laicasaane/126b6e3104f29e6828e16611c27e1e0f to your computer and use it in GitHub Desktop.
Test GC Alloc for struct to interface casting
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
using System; | |
using UnityEngine; | |
namespace Examples | |
{ | |
public partial class ExampleBehaviour : MonoBehaviour | |
{ | |
private static readonly UnityEngine.Profiling.Recorder s_recorder; | |
static ExampleBehaviour() | |
{ | |
s_recorder = UnityEngine.Profiling.Recorder.Get("GC.Alloc"); | |
} | |
private static int CountGCAllocs(Action action) | |
{ | |
s_recorder.FilterToCurrentThread(); | |
s_recorder.enabled = false; | |
s_recorder.enabled = true; | |
action(); | |
s_recorder.enabled = false; | |
return s_recorder.sampleBlockCount; | |
} | |
private void Start() | |
{ | |
EGIDSetter<ComponentA>.Warmup(); | |
CountGCAllocs(SetIDWithoutCasting); | |
var count = CountGCAllocs(SetIDWithoutCasting); | |
Debug.Log($"Set Without Casting: {count}"); | |
count = CountGCAllocs(SetIDWithCasting); | |
Debug.Log($"Set With Casting: {count}"); | |
} | |
private void SetIDWithoutCasting() | |
{ | |
var comp = new ComponentA(); | |
for (var i = 1; i <= 1_000_000; i++) | |
{ | |
var id = new EGID(i); | |
EGIDSetter<ComponentA>.SetIDWithoutCasting(ref comp, id); | |
} | |
} | |
private void SetIDWithCasting() | |
{ | |
var comp = new ComponentA(); | |
for (var i = 1; i <= 1_000_000; i++) | |
{ | |
var id = new EGID(i); | |
EGIDSetter<ComponentA>.SetIDWithCasting(ref comp, id); | |
} | |
} | |
private struct ComponentA : IEntityComponent, INeedEGID | |
{ | |
public EGID ID { get; set; } | |
public override string ToString() | |
=> ID.ToString(); | |
} | |
} | |
public struct EGID | |
{ | |
private readonly int _value; | |
public EGID(int value) | |
=> _value = value; | |
public override string ToString() | |
=> _value.ToString(); | |
} | |
public interface IEntityComponent { } | |
public interface INeedEGID | |
{ | |
EGID ID { get; set; } | |
} | |
delegate void SetEGIDAction<T>(ref T target, EGID egid) where T : struct, IEntityComponent; | |
static class EGIDSetter<T> where T : struct, IEntityComponent | |
{ | |
public static readonly SetEGIDAction<T> SetIDWithoutCasting = MakeSetter(); | |
public static void Warmup() { } | |
static SetEGIDAction<T> MakeSetter() | |
{ | |
var method = typeof(Trick).GetMethod(nameof(Trick.SetIDWihoutCasting)).MakeGenericMethod(typeof(T)); | |
return (SetEGIDAction<T>)System.Delegate.CreateDelegate(typeof(SetEGIDAction<T>), method); | |
} | |
public static void SetIDWithCasting(ref T target, EGID egid) | |
{ | |
if (target is INeedEGID needEGID) | |
{ | |
needEGID.ID = egid; | |
target = (T)needEGID; | |
} | |
} | |
static class Trick | |
{ | |
public static void SetIDWihoutCasting<U>(ref U target, EGID egid) where U : struct, INeedEGID | |
{ | |
target.ID = egid; | |
} | |
} | |
} | |
} |
Change the method of GC Alloc inspection
https://docs.microsoft.com/en-us/dotnet/api/system.gc.gettotalmemory?view=net-6.0
using System;
using System.Collections.Generic;
using UnityEngine;
namespace Examples
{
///vvvvvvvvvvvvvvvvvvvvvvvvvvv
/// Components
///vvvvvvvvvvvvvvvvvvvvvvvvvvv
public struct ComponentA : IEntityComponent, INeedEGID
{
public EGID ID { get; set; }
public override string ToString()
=> ID.ToString();
}
public struct EGID
{
private readonly int _value;
public EGID(int value)
=> _value = value;
public override string ToString()
=> _value.ToString();
}
public interface IEntityComponent { }
public interface INeedEGID
{
EGID ID { get; set; }
}
///vvvvvvvvvvvvvvvvvvvvvvvvvvv
/// EGIDSetter
///vvvvvvvvvvvvvvvvvvvvvvvvvvv
delegate void SetEGIDAction<T>(ref T target, EGID egid) where T : struct, IEntityComponent;
static class EGIDSetter<T> where T : struct, IEntityComponent
{
public static readonly SetEGIDAction<T> SetIDWithoutCasting = MakeSetter();
public static void Warmup() { }
static SetEGIDAction<T> MakeSetter()
{
var method = typeof(Trick).GetMethod(nameof(Trick.SetIDWihoutCasting)).MakeGenericMethod(typeof(T));
return (SetEGIDAction<T>)System.Delegate.CreateDelegate(typeof(SetEGIDAction<T>), method);
}
public static void SetIDWithCasting(ref T target, EGID egid)
{
if (target is INeedEGID needEGID)
{
needEGID.ID = egid;
target = (T)needEGID;
}
}
static class Trick
{
public static void SetIDWihoutCasting<U>(ref U target, EGID egid) where U : struct, INeedEGID
{
target.ID = egid;
}
}
}
///vvvvvvvvvvvvvvvvvvvvvvvvvvv
/// The Test starts here
///vvvvvvvvvvvvvvvvvvvvvvvvvvv
public partial class ExampleBehaviour : MonoBehaviour
{
private void Start()
{
EGIDSetter<ComponentA>.Warmup();
}
private void Update()
{
if (Input.GetKeyDown(KeyCode.Alpha1)
|| Input.GetKeyDown(KeyCode.Keypad1))
{
RunTest(false, false);
}
if (Input.GetKeyDown(KeyCode.Alpha2)
|| Input.GetKeyDown(KeyCode.Keypad2))
{
RunTest(true, false);
}
if (Input.GetKeyDown(KeyCode.Alpha3)
|| Input.GetKeyDown(KeyCode.Keypad3))
{
RunTest(true, true);
}
}
private void RunTest(bool runT2, bool runT3)
{
RunTest(1024, runT2, runT3);
Debug.Log("");
GC.Collect(0);
RunTest(1_048_576, runT2, runT3);
GC.Collect(0);
RunTestMultipleTimes(10, 1024, runT2, runT3);
RunTestMultipleTimes(10, 1_048_576, runT2, runT3);
}
private void RunTestMultipleTimes(int count, int max, bool runT2, bool runT3)
{
Debug.LogError($"Run test {count} times");
GC.Collect(0);
var t1 = 0L;
var t2 = 0L;
var t3 = 0L;
for (var i = 0; i < count; i++)
{
GC.Collect(0);
var (x1, x2, x3) = RunTest(max, runT2, runT3, false);
t1 += x1;
t2 += x2;
t3 += x3;
}
var avg1 = t1 / count;
var avg2 = t2 / count;
var avg3 = t3 / count;
Debug.LogWarning($"SetID_NoBoxing: x{max}");
Debug.Log($"Average increase: {avg1}");
Debug.LogWarning($"SetID_Boxing: x{max}");
Debug.Log($"Average increase: {avg2}");
Debug.LogWarning($"MakeSomeGarbage: {max} objects of System.Version");
Debug.Log($"Average increase: {avg3}");
}
private (long t1, long t2, long t3) RunTest(int max, bool runT2, bool runT3, bool canLog = true)
{
var gcTest = new GCTest {
Max = max
};
var gen0 = GC.GetGeneration(gcTest);
var gc0 = GC.GetTotalMemory(false);
gcTest.SetIDWithoutCasting();
var gen1 = GC.GetGeneration(gcTest);
var gc1 = GC.GetTotalMemory(false);
var diff1 = gc1 - gc0;
//GC.Collect(gen1);
long gen2 = 0;
long diff2 = 0;
long gc2 = gc0;
if (runT2)
{
gcTest.SetIDWithCasting();
gen2 = GC.GetGeneration(gcTest);
gc2 = GC.GetTotalMemory(false);
diff2 = gc2 - gc1;
}
long gen3 = 0;
long gc3 = 0;
long diff3 = 0;
if (runT3)
{
var versions = gcTest.MakeSomeGarbage();
gen3 = GC.GetGeneration(gcTest);
gc3 = GC.GetTotalMemory(false);
diff3 = gc3 - gc2;
}
if (canLog)
{
Debug.LogWarning("Initial");
Debug.Log($"Gen: {gen0} | Total Memory #0: {gc0}");
Debug.LogWarning($"SetID_NoBoxing: x{max}");
Debug.Log($"Gen: {gen1} | Total Memory #1: {gc1} | Increase: {diff1}");
if (runT2)
{
Debug.LogWarning($"SetID_Boxing: x{max}");
Debug.Log($"Gen: {gen2} | Total Memory #2: {gc2} | Increase: {diff2}");
}
if (runT3)
{
Debug.LogWarning($"MakeSomeGarbage: {max} objects of System.Version");
Debug.Log($"Gen: {gen3} | Total Memory #3: {gc3} | Increase: {diff3}");
}
}
return (diff1, diff2, diff3);
}
private class GCTest
{
public int Max { get; set; }
public void SetIDWithoutCasting()
{
var comp = new ComponentA();
for (var i = 1; i <= Max; i++)
{
var id = new EGID(i);
EGIDSetter<ComponentA>.SetIDWithoutCasting(ref comp, id);
}
}
public void SetIDWithCasting()
{
var comp = new ComponentA();
for (var i = 1; i <= Max; i++)
{
var id = new EGID(i);
EGIDSetter<ComponentA>.SetIDWithCasting(ref comp, id);
}
}
public List<Version> MakeSomeGarbage()
{
var versions = new List<Version>(Max);
for (var i = 1; i <= Max; i++)
{
versions.Add(new Version());
}
return versions;
}
}
}
}
The result of this method clearly show that casting a struct to interface will incur boxing at runtime.
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
IL2CPP generated code for
EGIDSetter<T>.Trick.SetIDWithoutCasting
method