网站优化公司seo案例,兰州易天网站建设公司有哪些?,设计师网站十大网站,做网站的工作要求为了使锁定机制允许锁定多个读取器(而不是一个写入器)访问某个资源#xff0c;可以使用 ReaderWriterLockSlim 类。这个类提供了一个锁定功能#xff0c;如果没有写入器锁定资源#xff0c;就允许多个读取器访问资源#xff0c;但只能有一个写入器锁定该资源。ReaderWriter… 为了使锁定机制允许锁定多个读取器(而不是一个写入器)访问某个资源可以使用 ReaderWriterLockSlim 类。这个类提供了一个锁定功能如果没有写入器锁定资源就允许多个读取器访问资源但只能有一个写入器锁定该资源。ReaderWriterLockSlim 类有阻塞或不阻塞的方法来获取读取锁如阻塞的EnterReadLock() 和不阻塞的 TryEnterReadLock() 方法还可以使用阻塞的EnterWriteLock() 和不阻塞的 TryEnterWriteLock() 方法获得写入锁定。如果任务先读取资源,之后写入资源,它就可以使用 EnterUpgradableReadLock() 或 TryEnterUpgradableReadLock() 方法获得可升级的读取锁定。有了这个锁定就可以获得写入锁定而不需要释放读取锁定。这个类的几个属性提供了当前锁定的相关信息。如CurrentReadCount、WaitingReadCount、WaitingUpgradableReadCount 和 WaitingWriteCount。下面的示例程序创建了一个包含 6 项的集合和一个 ReaderWriterLockSlim() 对象。ReaderMethod() 方法获得一个读取锁定读取列表中的所有项并把它们写到控制台中。WriterMethod(0 方法试图获得一个写入锁定以改变集合的所有值。在Main()方法中启动6个任务以调用 ReaderMethod()或WriterMethod()方法。class Program
{private static Listint _items new Listint() { 012345}; private static ReaderWriterLockSlim _rwl new ReaderWriterLockSlim(LockRecursionPolicy.SupportsRecursion);public static void ReaderMethod(object reader)
{try{_rwl.EnterReadLock();For (int i 0; i _items.Count; i){Console.WriteLine($reader {reader}, loop: {i}, item: {_items[i]}); Task.Delay(40).Wait();}}finally{_rwl.ExitReadLock();}}public static void WriterMethod(object writer)
{try{while (!_rwl.TryEnterWriteLock(50)){Console.WriteLine($Writer {writer} waiting for the write lock); Console.WriteLine($current reader count:(_rwl.CurrentReadCount});}Console.WriteLine($Writer {writer) acquired the lock);for (int i 0; i _items.Count; i){_items[i];Task.Delay(50).Wait();}Console.WriteLine($Writer {writer} finished);}finally{_rwl.ExitWriteLock();}}static void Main()
{var taskFactory new TaskFactory(TaskCreationOptions.LongRunning,TaskContinuationOptions.None); var tasks new Task[6];tasks[0] taskFactory.StartNew(WriterMethod, 1); tasks[1] taskFactory.StartNew(ReaderMethod, 1);tasks[2] taskFactory.StartNew(ReaderMethod, 2);tasks[3] taskFactory.StartNew(WriterMethod, 2);tasks[4] taskFactory.StartNew(ReaderMethod, 3); tasks[5] taskFactory.StartNew(ReaderMethod, 4); Task.WaitAll(tasks);}}运行这个应用程序可以看到第一个写入器先获得锁定。第二个写入器和所有的读取器需要等待。接着读取器可以同时工作而第二个写入器仍在等待资源。 Writer 1 acquired the lock
Writer 2 waiting for the write lock
current reader count: 0
Writer 2 waiting for the write lock
current reader count: 0
Writer 2 waiting for the write lock
current reader count: 0
Writer 2 waiting for the write lock
current reader count: 0
Writer 1 finished
reader 4, loop: 0item: 1
reader 1, loop: 0, item: 1
Writer 2 waiting for the write lock
current reader count: 4
reader 2, loop: 0item: 1
reader 3, loop: 0, item: 1
reader 4loop: 1, item: 2
reader 1, loop: 1, item: 2
reader 3, loop: 1item: 2
reader 2, loop: 1, item: 2
Writer 2 waiting for the write lock
current reader count: 4
reader 4, loop: 2, item: 3
reader l, loop: 2item: 3
reader 2, loop: 2item: 3
reader 3, loop: 2, item: 3
Writer 2 waiting for the write lock
current reader count: 4
reader 4, loop: 3, item: 4
reader 1, loop: 3item: 4
reader 2, loop: 3, item: 4
reader 3, loop: 3, item: 4
reader 4, loop: 4, item: 5
reader 1, loop: 4, item: 5
Writer 2 waiting for the write lock
current reader count: 4
reader 2, loop: 4, item: 5
reader 3, loop: 4, item: 5
reader 4, loop: 5, item: 6
reader 1loop: 5item: 6
reader 2, loop: 5, item: 6
reader 3, loop: 5, item: 6
Writer 2 waiting for the write lock
current reader count: 4
Writer 2 acquired the lock
Writer 2 finished 微信公众号 Dotnet讲堂
