intermediate Utilities

Generic Singleton

Thread-safe, persistent singleton base class for managers like AudioManager, GameManager, etc.

Unity 2022.3+ · 1.2 KB · Singleton.cs

How to Use

Create your manager class inheriting from Singleton:

public class AudioManager : Singleton { }

Access anywhere with AudioManager.Instance

The singleton persists across scene loads automatically

Features

Generic base class — inherit to make any MonoBehaviour a singleton
Thread-safe access with lock object for multi-threaded scenarios
Auto-creates instance if none exists in the scene
DontDestroyOnLoad persistence across scene changes
Duplicate destruction — extra instances are automatically removed
Application quit guard prevents ghost instances during shutdown

When to Use This

Use whenever you need a single global manager that persists across scenes — GameManager, AudioManager, SaveManager, InputManager, etc. Perfect for any game architecture that requires centralized systems accessible from anywhere via a static Instance property. Especially useful in larger projects with multiple scenes.

Common Mistakes

Placing two GameObjects with the same Singleton subclass in a scene will cause one to be destroyed immediately — this is intended, but can be confusing. If you override Awake() in your subclass, you must call base.Awake() or the singleton setup breaks. Accessing Instance during OnDestroy or OnApplicationQuit may return null due to the isQuitting guard.

Source Code

  
 Singleton.cs
C# 
using UnityEngine;

/// <summary>
/// Generic singleton base class. Inherit from this to create a singleton manager.
/// Usage: public class GameManager : Singleton<GameManager> { }
/// </summary>
public abstract class Singleton<T> : MonoBehaviour where T : MonoBehaviour
{
    private static T instance;
    private static readonly object lockObj = new object();
    private static bool isQuitting;

    public static T Instance
    {
        get
        {
            if (isQuitting)
                return null;

            lock (lockObj)
            {
                if (instance == null)
                {
                    instance = FindAnyObjectByType<T>();

                    if (instance == null)
                    {
                        var go = new GameObject(typeof(T).Name);
                        instance = go.AddComponent<T>();
                    }
                }
                return instance;
            }
        }
    }

    protected virtual void Awake()
    {
        if (instance == null)
        {
            instance = this as T;
            DontDestroyOnLoad(gameObject);
        }
        else if (instance != this)
        {
            Destroy(gameObject);
        }
    }

    private void OnApplicationQuit()
    {
        isQuitting = true;
    }
}
 54 lines

Related Scripts

Audio Intermediate

Audio Manager

Complete audio manager with music crossfade, SFX pooling, volume control, and persistence.

General

public class AudioManager : MonoBehaviour
{
    public static AudioManager Instance { get; private set; }
    public void PlaySFX(AudioClip clip, float volumeScale = 1f)
    public void PlayMusic(AudioClip clip, bool crossfade = true)

2022.3+ · 4.5 KB

Utilities Beginner

Scene Manager

Async scene loading with loading screen, progress bar, and minimum load time. Clean transitions b...

General

public class SceneLoader : MonoBehaviour
{
    public static SceneLoader Instance { get; private set; }
    public void LoadScene(string sceneName)
    private IEnumerator LoadSceneAsync(string sceneName)

2022.3+ · 2.5 KB