/********************************************************************************
** 类名称： SemaphorePool
** 描述  ： 用于线程信号量的处理类
** 作者  ： 丁书杰
** 创建时间：2019/03/26
** 版权所有 (C) :中科视语（北京）科技有限公司
*********************************************************************************/
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading;

namespace OS.Spin.Common.MultiThread
{
    public class SemaphorePool
    {
        private Dictionary<string, Semaphore> _sPool = new Dictionary<string, Semaphore>();

        private static SemaphorePool _cDk;
        private static readonly object ObjLock = new object();

        public static SemaphorePool GetInstance()
        {
            lock (ObjLock)
            {
                return _cDk ?? (_cDk = new SemaphorePool());
            }
        }

        /// <summary>
        /// 创建一个信号量
        /// </summary>
        /// <param name="key">信号量的名称</param>
        /// <param name="multiThread">并发信号量的个数</param>
        public void MakeSemaphore(string key, int multiThread = 1)
        {
            _sPool[key] = new Semaphore(0, multiThread);
        }

        /// <summary>
        /// 移出一个信号量
        /// </summary>
        /// <param name="key">需要移出信号量的名称</param>
        public void CleanSemaphore(string key)
        {
            if (!_sPool.Keys.Contains(key))
            {
                return;
            }

            _sPool.Remove(key);
        }

        public bool Release(string key, int n = 1)
        {
            if(!_sPool.Keys.Contains(key))
            {
                return true;
            }
            try
            {
                _sPool[key].Release(n);
                return true;
            }
            catch (Exception)
            {
                return false;
            }            
        }

        public void Wait(string key)
        {
            if (!_sPool.Keys.Contains(key))
            {
                return;
            }

            _sPool[key].WaitOne();
        }
    }
}