概述
ReaderWriterLockSlim 表示用于管理资源访问的锁定状态,可实现多线程读取或进行独占式写入访问;
常用的方法:
cacheLock.EnterReadLock();//加上读取锁 cacheLock.ExitReadLock();//退出读取锁
cacheLock.EnterWriteLock()//加上写入锁;
cacheLock.ExitWriteLock();//退出写入锁
cacheLock.TryEnterWriteLock(timeout);//加上超时锁
cacheLock.EnterUpgradeableReadLock();尝试进入可升级模式锁定状态。
cacheLock.ExitUpgradeableReadLock();尝试进入可升级模式锁定状态。
MSDN的DEMO如下:
using System; using System.Threading; using System.Collections.Generic; public class SynchronizedCache { private ReaderWriterLockSlim cacheLock = new ReaderWriterLockSlim(); private Dictionary<int, string> innerCache = new Dictionary<int, string>(); public string Read(int key) { cacheLock.EnterReadLock(); try { return innerCache[key]; } finally { cacheLock.ExitReadLock(); } } public void Add(int key, string value) { cacheLock.EnterWriteLock(); try { innerCache.Add(key, value); } finally { cacheLock.ExitWriteLock(); } } public bool AddWithTimeout(int key, string value, int timeout) { if (cacheLock.TryEnterWriteLock(timeout)) { try { innerCache.Add(key, value); } finally { cacheLock.ExitWriteLock(); } return true; } else { return false; } } public AddOrUpdateStatus AddOrUpdate(int key, string value) { cacheLock.EnterUpgradeableReadLock(); try { string result = null; if (innerCache.TryGetValue(key, out result)) { if (result == value) { return AddOrUpdateStatus.Unchanged; } else { cacheLock.EnterWriteLock(); try { innerCache[key] = value; } finally { cacheLock.ExitWriteLock(); } return AddOrUpdateStatus.Updated; } } else { cacheLock.EnterWriteLock(); try { innerCache.Add(key, value); } finally { cacheLock.ExitWriteLock(); } return AddOrUpdateStatus.Added; } } finally { cacheLock.ExitUpgradeableReadLock(); } } public void Delete(int key) { cacheLock.EnterWriteLock(); try { innerCache.Remove(key); } finally { cacheLock.ExitWriteLock(); } } public enum AddOrUpdateStatus { Added, Updated, Unchanged }; }
时间: 2024-10-09 03:37:11