c# - 使用互斥锁来锁定对象

Question

我有一个应用程序创建了一个需要锁定的对象，因为该对象创建了一个外部硬件设备对象(通过第三方 DLL)，并且该硬件设备对象只能创建一次。当启动此应用程序的多个实例时，只有第一个实例应该能够创建此 C# 对象。子序列实例应该看到该对象已被锁定并且无法创建对象。我使用了互斥体，因为此对象创建发生在多个应用程序实例(多个进程)中。但是，代码不会使用互斥体锁定。我是否正在运行多个实例，其中每个实例都创建自己的锁？

public sealed class MyObject
{
    private static MyObject _myObject;
    static ExtDeviceDriver devDrv;
    private readonly static Mutex mut = new Mutex();

    private MyObject()
    {
        mut.WaitOne();
        //Thread safe code here.
        devDrv = new ExtDeviceDriver();
    }

    ~MyObject()
    {
        mut.ReleaseMutex();
    }

    // object accessor
    public static MyObject GetMyObject
    {
        get
        {
            if (_myObject == null)
                _myObject = new MyObject();
            return _myObject;   
        }
    }
}

Answer 1

我想你应该使用命名互斥体(See this article on MSDN)。

Mutexes are of two types: local mutexes and named system mutexes. If you create a Mutex object using a constructor that accepts a name, it is associated with an operating-system object of that name. Named system mutexes are visible throughout the operating system and can be used to synchronize the activities of processes. You can create multiple Mutex objects that represent the same named system mutex, and you can use the OpenExisting method to open an existing named system mutex.

所以，尝试使用这个constructor创建一个命名的互斥体。此外，您应该检查它是否已经存在 Mutex.OpenExisting Method (考虑这篇文章中给出的示例；它告诉我们如何检查、创建、利用命名互斥体)。

编辑

参见Mutex Class :

You can use the WaitHandle.WaitOne method to request ownership of a mutex. The thread that owns a mutex can request the same mutex in repeated calls to WaitOne without blocking its execution. However, the thread must call the ReleaseMutex method the same number of times to release ownership of the mutex. The Mutex class enforces thread identity, so a mutex can be released only by the thread that acquired it.

和Mutex Constructor (Boolean, String) ，也就是说，必须将 bool 参数设置为:

true to give the calling thread initial ownership of the named system mutex if the named system mutex is created as a result of this call; otherwise, false.