问题描述

它是什么以及如何使用?

What is it and how to use?

我需要它，因为我有一个每秒插入数据库的计时器，并且我在计时器处理程序和主线程之间有一个共享资源.我想保证如果计时器处理程序在插入中花费的时间超过一秒，则应按顺序执行等待的线程.这是我的计时器处理程序的示例代码:

I need that as I have a timer that inserts into DB every second, and I have a shared resource between timer handler and the main thread. I want to gurantee that if the timer handler takes more than one second in the insertion the waited threads should be executed in order. This is a sample code for my timer handler:

private void InsertBasicVaraibles(object param)
{
    try
    {
        DataTablesMutex.WaitOne();//mutex for my shared resources
         //insert into DB
    }
    catch (Exception ex)
    {
        //Handle
    }
    finally
    {
        DataTablesMutex.ReleaseMutex();
    }
}

但目前互斥体不保证任何顺序.

But currently the mutex does not guarantee any order.

推荐答案

您需要编写自己的类来执行此操作，我找到了这个示例(粘贴，因为它看起来好像站点的域已失效):

You'll need to write your own class to do this, I found this example (pasted because it looks as though the site's domain has lapsed):

using System.Threading;

public sealed class QueuedLock
{
    private object innerLock;
    private volatile int ticketsCount = 0;
    private volatile int ticketToRide = 1;

    public QueuedLock()
    {
        innerLock = new Object();
    }

    public void Enter()
    {
        int myTicket = Interlocked.Increment(ref ticketsCount);
        Monitor.Enter(innerLock);
        while (true)
        {

            if (myTicket == ticketToRide)
            {
                return;
            }
            else
            {
                Monitor.Wait(innerLock);
            }
        }
    }

    public void Exit()
    {
        Interlocked.Increment(ref ticketToRide);
        Monitor.PulseAll(innerLock);
        Monitor.Exit(innerLock);
    }
}

使用示例:

QueuedLock queuedLock = new QueuedLock();

try
{
   queuedLock.Enter();
   // here code which needs to be synchronized
   // in correct order
}
finally
{
    queuedLock.Exit();
}

Source via archive.org

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