Unity & C# ~ Object Pool

using System.Collections.Generic;
using UnityEngine;

public class ObjectPool : MonoBehaviour
{
    private static ObjectPool instance = null;
    private static object _syncObj = new object();
    
    public static ObjectPool Instance
    {
        get
        {
            lock (_syncObj)
            {
                if (instance == null)
                {
                    ObjectPool objs = FindObjectOfType<ObjectPool>();

                    if (instance == null)
                    {
                        GameObject go = new GameObject(name);
                        instance = go.AddComponent<ObjectPool>();
                    }
                    else
                    {
                        instance = objs;
                    }
                }
                return instance;
            }
        }
    }
    
    private Dictionary<string, Queue<GameObject>> objectPoolDic = new Dictionary<string, Queue<GameObject>>();

    // 신규 오브젝트 생성
    public GameObject CreateNewObject(GameObject _obj)
    {
        var newObj = Instantiate(_obj);
        newObj.SetActive(false);
        newObj.transform.SetParent(transform);

        return newObj;
    }
    
    // pool 초기화
    public void InitializeDic(string strKey, GameObject _obj, int addValue)
    {
        if (objectPoolDic.ContainsKey(strKey) == false)
        {
            objectPoolDic.Add(strKey, new Queue<GameObject>());
        }

        for (int i = 0; i < addValue; i++)
        {
            objectPoolDic[strKey].Enqueue(CreateNewObject(_obj));
        }
    }

    // pool 꺼내기
    public static GameObject GetObject(string strKey, GameObject pObj)
    {
        GameObject _obj = null;

        Instance.objectPoolDic.TryGetValue(strKey, out var getQue);

        if (getQue != null)
        {
            if(getQue.Count > 0)
            {
                _obj = getQue.Dequeue();
            }
            else
            {
                _obj = Instance.CreateNewObject(pObj);
            }

            _obj.transform.SetParent(null);
            _obj.SetActive(true);
        }

        return _obj;
    }

    // pool 넣기
    public static void ReturnObject(string strKey, GameObject pObj)
    {
        pObj.SetActive(false);
        pObj.transform.SetParent(Instance.transform);

        Instance.objectPoolDic.TryGetValue(strKey, out var getQue);

        if (getQue == null)
        {
            Instance.objectPoolDic.Add(strKey, new Queue<GameObject>());
            Instance.objectPoolDic[strKey].Enqueue(pObj);
        }
        else
        {
            getQue.Enqueue(pObj);
        }
    }
}