Mutex 构造函数

定义

命名空间:

System.Threading

程序集:

System.Threading.dll

初始化 Mutex 类的新实例。

重载

Mutex()	使用默认属性初始化 Mutex 类的新实例。
Mutex(Boolean)	使用 Boolean 值（指示调用线程是否应具有互斥体的初始所有权）初始化 Mutex 类的新实例。
Mutex(Boolean, String)	使用 Boolean 值（指示调用线程是否应具有互斥体的初始所有权以及字符串是否为互斥体的名称）初始化 Mutex 类的新实例。
Mutex(Boolean, String, Boolean)	使用可指示调用线程是否应具有互斥体的初始所有权以及字符串是否为互斥体的名称的 Boolean 值和当线程返回时可指示调用线程是否已赋予互斥体的初始所有权的 Boolean 值初始化 Mutex 类的新实例。

Mutex()

Source:

Mutex.cs

使用默认属性初始化 Mutex 类的新实例。

public:
 Mutex();

public Mutex ();

Public Sub New ()

示例

下面的代码示例演示如何使用本地 Mutex 对象来同步对受保护资源的访问。 创建互斥体的线程最初并不拥有它。

// This example shows how a Mutex is used to synchronize access
// to a protected resource. Unlike Monitor, Mutex can be used with
// WaitHandle.WaitAll and WaitAny, and can be passed across
// AppDomain boundaries.
using namespace System;
using namespace System::Threading;
const int numIterations = 1;
const int numThreads = 3;
ref class Test
{
public:

   // Create a new Mutex. The creating thread does not own the
   // Mutex.
   static Mutex^ mut = gcnew Mutex;
   static void MyThreadProc()
   {
      for ( int i = 0; i < numIterations; i++ )
      {
         UseResource();

      }
   }


private:

   // This method represents a resource that must be synchronized
   // so that only one thread at a time can enter.
   static void UseResource()
   {
      
      //Wait until it is OK to enter.
      mut->WaitOne();
      Console::WriteLine( "{0} has entered protected the area", Thread::CurrentThread->Name );
      
      // Place code to access non-reentrant resources here.
      // Simulate some work.
      Thread::Sleep( 500 );
      Console::WriteLine( "{0} is leaving protected the area\r\n", Thread::CurrentThread->Name );
      
      // Release the Mutex.
      mut->ReleaseMutex();
   }

};

int main()
{
   
   // Create the threads that will use the protected resource.
   for ( int i = 0; i < numThreads; i++ )
   {
      Thread^ myThread = gcnew Thread( gcnew ThreadStart( Test::MyThreadProc ) );
      myThread->Name = String::Format( "Thread {0}", i + 1 );
      myThread->Start();

   }
   
   // The main thread exits, but the application continues to 
   // run until all foreground threads have exited.
}

// This example shows how a Mutex is used to synchronize access
// to a protected resource. Unlike Monitor, Mutex can be used with
// WaitHandle.WaitAll and WaitAny, and can be passed across
// AppDomain boundaries.
 
using System;
using System.Threading;

class Test13
{
    // Create a new Mutex. The creating thread does not own the
    // Mutex.
    private static Mutex mut = new Mutex();
    private const int numIterations = 1;
    private const int numThreads = 3;

    static void Main()
    {
        // Create the threads that will use the protected resource.
        for(int i = 0; i < numThreads; i++)
        {
            Thread myThread = new Thread(new ThreadStart(MyThreadProc));
            myThread.Name = String.Format("Thread{0}", i + 1);
            myThread.Start();
        }

        // The main thread exits, but the application continues to
        // run until all foreground threads have exited.
    }

    private static void MyThreadProc()
    {
        for(int i = 0; i < numIterations; i++)
        {
            UseResource();
        }
    }

    // This method represents a resource that must be synchronized
    // so that only one thread at a time can enter.
    private static void UseResource()
    {
        // Wait until it is safe to enter.
        mut.WaitOne();

        Console.WriteLine("{0} has entered the protected area", 
            Thread.CurrentThread.Name);

        // Place code to access non-reentrant resources here.

        // Simulate some work.
        Thread.Sleep(500);

        Console.WriteLine("{0} is leaving the protected area\r\n", 
            Thread.CurrentThread.Name);
         
        // Release the Mutex.
        mut.ReleaseMutex();
    }
}

' This example shows how a Mutex is used to synchronize access
' to a protected resource. Unlike Monitor, Mutex can be used with
' WaitHandle.WaitAll and WaitAny, and can be passed across
' AppDomain boundaries.
 
Imports System.Threading

Class Test
    ' Create a new Mutex. The creating thread does not own the
    ' Mutex.
    Private Shared mut As New Mutex()
    Private Const numIterations As Integer = 1
    Private Const numThreads As Integer = 3

    <MTAThread> _
    Shared Sub Main()
        ' Create the threads that will use the protected resource.
        Dim i As Integer
        For i = 1 To numThreads
            Dim myThread As New Thread(AddressOf MyThreadProc)
            myThread.Name = [String].Format("Thread{0}", i)
            myThread.Start()
        Next i

        ' The main thread exits, but the application continues to
        ' run until all foreground threads have exited.

    End Sub

    Private Shared Sub MyThreadProc()
        Dim i As Integer
        For i = 1 To numIterations
            UseResource()
        Next i
    End Sub

    ' This method represents a resource that must be synchronized
    ' so that only one thread at a time can enter.
    Private Shared Sub UseResource()
        ' Wait until it is safe to enter.
        mut.WaitOne()

        Console.WriteLine("{0} has entered protected area", _
            Thread.CurrentThread.Name)

        ' Place code to access non-reentrant resources here.

        ' Simulate some work
        Thread.Sleep(500)

        Console.WriteLine("{0} is leaving protected area" & vbCrLf, _
            Thread.CurrentThread.Name)

        ' Release Mutex.
        mut.ReleaseMutex()
    End Sub
End Class

注解

调用此构造函数重载与调用 Mutex(Boolean) 构造函数重载并指定 false 互斥体的初始所有权相同。 也就是说，调用线程不拥有互斥体。

另请参阅

• 托管线程
• Mutex

Mutex(Boolean)

Source:

Mutex.cs

使用 Boolean 值（指示调用线程是否应具有互斥体的初始所有权）初始化 Mutex 类的新实例。

public:
 Mutex(bool initiallyOwned);

public Mutex (bool initiallyOwned);

new System.Threading.Mutex : bool -> System.Threading.Mutex

Public Sub New (initiallyOwned As Boolean)

参数

initiallyOwned

Boolean

如果给调用线程赋予互斥体的初始所属权，则为 true；否则为 false。

示例

下面的代码示例演示如何使用本地 Mutex 对象来同步对受保护资源的访问。 创建 的 Mutex 线程最初拥有它。

using namespace System;
using namespace System::Threading;

const int numIterations = 1;
const int numThreads = 3;

ref class Test
{
public:

   // Create a new Mutex. The creating thread owns the
   // Mutex.
   static Mutex^ mut = gcnew Mutex( true );
   static void MyThreadProc()
   {
      for ( int i = 0; i < numIterations; i++ )
      {
         UseResource();

      }
   }


private:

   // This method represents a resource that must be synchronized
   // so that only one thread at a time can enter.
   static void UseResource()
   {
      
      //Wait until it is OK to enter.
      mut->WaitOne();
      Console::WriteLine( "{0} has entered protected the area", Thread::CurrentThread->Name );
      
      // Place code to access non-reentrant resources here.
      // Simulate some work.
      Thread::Sleep( 500 );
      Console::WriteLine( "{0} is leaving protected the area\r\n", Thread::CurrentThread->Name );
      
      // Release the Mutex.
      mut->ReleaseMutex();
   }

};

int main()
{
   
   // Initialize the Mutex.
   Mutex^ mut = Test::mut;
   
   // Create the threads that will use the protected resource.
   for ( int i = 0; i < numThreads; i++ )
   {
      Thread^ myThread = gcnew Thread( gcnew ThreadStart( Test::MyThreadProc ) );
      myThread->Name = String::Format( "Thread {0}", i + 1 );
      myThread->Start();

   }
   
   // Wait one second before allowing other threads to
   // acquire the Mutex.
   Console::WriteLine( "Creating thread owns the Mutex." );
   Thread::Sleep( 1000 );
   Console::WriteLine( "Creating thread releases the Mutex.\r\n" );
   mut->ReleaseMutex();
}
// The example displays output like the following:
//       Creating thread owns the Mutex.
//       Creating thread releases the Mutex.
//       
//       Thread1 has entered the protected area
//       Thread1 is leaving the protected area
//       
//       Thread2 has entered the protected area
//       Thread2 is leaving the protected area
//       
//       Thread3 has entered the protected area
//       Thread3 is leaving the protected area

using System;
using System.Threading;

class Test
{
    private static Mutex mut;
    private const int numIterations = 1;
    private const int numThreads = 3;

    static void Main()
    {
        // Create a new Mutex. The creating thread owns the Mutex.
        mut = new Mutex(true);
        // Create the threads that will use the protected resource.
        for(int i = 0; i < numThreads; i++)
        {
            Thread myThread = new Thread(new ThreadStart(MyThreadProc));
            myThread.Name = String.Format("Thread{0}", i + 1);
            myThread.Start();
        }

        // Wait one second before allowing other threads to
        // acquire the Mutex.
        Console.WriteLine("Creating thread owns the Mutex.");
        Thread.Sleep(1000);

        Console.WriteLine("Creating thread releases the Mutex.\r\n");
        mut.ReleaseMutex();
    }

    private static void MyThreadProc()
    {
        for(int i = 0; i < numIterations; i++)
        {
            UseResource();
        }
    }

    // This method represents a resource that must be synchronized
    // so that only one thread at a time can enter.
    private static void UseResource()
    {
        // Wait until it is safe to enter.
        mut.WaitOne();

        Console.WriteLine("{0} has entered the protected area", 
            Thread.CurrentThread.Name);

        // Place code to access non-reentrant resources here.

        // Simulate some work.
        Thread.Sleep(500);

        Console.WriteLine("{0} is leaving the protected area\r\n", 
            Thread.CurrentThread.Name);
         
        // Release the Mutex.
        mut.ReleaseMutex();
    }
}
// The example displays output like the following:
//       Creating thread owns the Mutex.
//       Creating thread releases the Mutex.
//       
//       Thread1 has entered the protected area
//       Thread1 is leaving the protected area
//       
//       Thread2 has entered the protected area
//       Thread2 is leaving the protected area
//       
//       Thread3 has entered the protected area
//       Thread3 is leaving the protected area

Imports System.Threading

Class Test
    ' Create a new Mutex. The creating thread owns the
    ' Mutex.
    Private Shared mut As New Mutex(True)
    Private Const numIterations As Integer = 1
    Private Const numThreads As Integer = 3

    <MTAThread> _
    Shared Sub Main()
        ' Create the threads that will use the protected resource.
        Dim i As Integer
        For i = 1 To numThreads
            Dim myThread As New Thread(AddressOf MyThreadProc)
            myThread.Name = [String].Format("Thread{0}", i)
            myThread.Start()
        Next i

        ' Wait one second before allowing other threads to
        ' acquire the Mutex.
        Console.WriteLine("Creating thread owns the Mutex.")
        Thread.Sleep(1000)

        Console.WriteLine("Creating thread releases the Mutex." & vbCrLf)
        mut.ReleaseMutex()
    End Sub

    Private Shared Sub MyThreadProc()
        Dim i As Integer
        For i = 1 To numIterations
            UseResource()
        Next i
    End Sub

    ' This method represents a resource that must be synchronized
    ' so that only one thread at a time can enter.
    Private Shared Sub UseResource()
        ' Wait until it is safe to enter.
        mut.WaitOne()

        Console.WriteLine("{0} has entered protected area", _
            Thread.CurrentThread.Name)

        ' Place code to access non-reentrant resources here.

        ' Simulate some work
        Thread.Sleep(500)

        Console.WriteLine("{0} is leaving protected area" & vbCrLf, _
            Thread.CurrentThread.Name)

        ' Release Mutex.
        mut.ReleaseMutex()
    End Sub
End Class
' The example displays output like the following:
'       Creating thread owns the Mutex.
'       Creating thread releases the Mutex.
'       
'       Thread1 has entered the protected area
'       Thread1 is leaving the protected area
'       
'       Thread2 has entered the protected area
'       Thread2 is leaving the protected area
'       
'       Thread3 has entered the protected area
'       Thread3 is leaving the protected area

另请参阅

• 托管线程
• Mutex

Mutex(Boolean, String)

Source:

Mutex.cs

使用 Boolean 值（指示调用线程是否应具有互斥体的初始所有权以及字符串是否为互斥体的名称）初始化 Mutex 类的新实例。

public:
 Mutex(bool initiallyOwned, System::String ^ name);

public Mutex (bool initiallyOwned, string? name);

new System.Threading.Mutex : bool * string -> System.Threading.Mutex

Public Sub New (initiallyOwned As Boolean, name As String)

参数

initiallyOwned

Boolean

如果为 true，则给予调用线程已命名的系统互斥体的初始所属权（如果已命名的系统互斥体是通过此调用创建的）；否则为 false。

name

String

如果要与其他进程共享同步对象，则为名称；否则为 null 或空字符串。 该名称区分大小写。 反斜杠字符 (\) 是保留的，只能用于指定命名空间。 有关命名空间的详细信息，请参阅备注部分。 根据操作系统，名称可能会有进一步的限制。 例如，在基于 Unix 的操作系统上，排除命名空间后的名称必须是有效的文件名。

例外

UnauthorizedAccessException

命名互斥体存在且具有访问控制安全性，但用户不具备 FullControl。

IOException

name 无效。 导致这种情况的原因有很多，包括操作系统可能会施加的一些限制，例如未知前缀或无效字符。 请注意，名称和常见前缀“Global\”和“Local\”区分大小写。

或

还有其他一些错误。 HResult 属性可能提供更多信息。

DirectoryNotFoundException

仅限 Windows：name 指定了未知命名空间。 有关详细信息，请参阅对象名称。

PathTooLongException

name 太长。 长度限制可能取决于操作系统或配置。

WaitHandleCannotBeOpenedException

无法创建具有提供的 name 的同步对象。 不同类型的同步对象可能具有相同的名称。

ArgumentException

仅限 .NET Framework：name 的长度超过 MAX_PATH（260 个字符）。

示例

以下示例演示如何使用命名互斥体在两个单独的进程中运行的线程之间发出信号。

从两个或多个命令窗口运行此程序。 每个进程都会创建一个 Mutex 对象，该对象表示命名的互斥体 MyMutex。 命名 mutex 是一个系统对象，其生存期由表示它的 对象的生存期 Mutex 限制。 命名 mutex 是在第一个进程创建其 Mutex 对象时创建的;在此示例中，命名 mutex 由运行程序的第一个进程拥有。 当已释放所有表示它的对象时， Mutex 将销毁命名的 mutex。

此示例中使用的构造函数重载无法告诉调用线程是否已授予命名 mutex 的初始所有权。 除非可以确定线程将创建命名互斥体，否则不应使用此构造函数请求初始所有权。

using namespace System;
using namespace System::Threading;

int main()
{
   // Create the named mutex. Only one system object named 
   // "MyMutex" can exist; the local Mutex object represents 
   // this system object, regardless of which process or thread
   // caused "MyMutex" to be created.
   Mutex^ m = gcnew Mutex( false,"MyMutex" );
   
   // Try to gain control of the named mutex. If the mutex is 
   // controlled by another thread, wait for it to be released.        
   Console::WriteLine(  "Waiting for the Mutex." );
   m->WaitOne();
   
   // Keep control of the mutex until the user presses
   // ENTER.
   Console::WriteLine( "This application owns the mutex. "
   "Press ENTER to release the mutex and exit." );
   Console::ReadLine();
   m->ReleaseMutex();
}

using System;
using System.Threading;

public class Test1
{
    public static void Main()
    {
        // Create the named mutex. Only one system object named 
        // "MyMutex" can exist; the local Mutex object represents 
        // this system object, regardless of which process or thread
        // caused "MyMutex" to be created.
        Mutex m = new Mutex(false, "MyMutex");
        
        // Try to gain control of the named mutex. If the mutex is 
        // controlled by another thread, wait for it to be released.        
        Console.WriteLine("Waiting for the Mutex.");
        m.WaitOne();

        // Keep control of the mutex until the user presses
        // ENTER.
        Console.WriteLine("This application owns the mutex. " +
            "Press ENTER to release the mutex and exit.");
        Console.ReadLine();

        m.ReleaseMutex();
    }
}

Imports System.Threading

Public Class Test
   Public Shared Sub Main()
      ' Create the named mutex. Only one system object named 
      ' "MyMutex" can exist; the local Mutex object represents 
      ' this system object, regardless of which process or thread
      ' caused "MyMutex" to be created.
      Dim m As New Mutex(False, "MyMutex")
      
      ' Try to gain control of the named mutex. If the mutex is 
      ' controlled by another thread, wait for it to be released.        
      Console.WriteLine("Waiting for the Mutex.")
      m.WaitOne()
      
      ' Keep control of the mutex until the user presses
      ' ENTER.
      Console.WriteLine("This application owns the mutex. " _
          & "Press ENTER to release the mutex and exit.")
      Console.ReadLine()
      
      m.ReleaseMutex()
   End Sub 
End Class

注解

name可以使用 或 Local\ 作为前缀Global\来指定命名空间。 Global指定命名空间后，可以与系统上的任何进程共享同步对象。 如果指定了 Local 命名空间（如果未指定命名空间，这也是默认命名空间），则同步对象可以与同一会话中的进程共享。 在 Windows 上，会话是登录会话，服务通常在不同的非交互式会话中运行。 在类似 Unix 的操作系统上，每个 shell 都有自己的会话。 会话本地同步对象可能适合在具有父/子关系的进程之间进行同步，这些进程都在同一会话中运行。 有关 Windows 上的同步对象名称的详细信息，请参阅 对象名称。

如果提供了 ， name 并且命名空间中已存在请求类型的同步对象，则使用现有同步对象。 如果命名空间中已存在不同类型的同步对象， WaitHandleCannotBeOpenedException 则会引发 。 否则，将创建新的同步对象。

如果 name 不是 null 且 initiallyOwned 为 true，则仅当命名系统互斥体是由此调用的结果创建的时，调用线程才拥有互斥体。 由于没有用于确定是否创建了命名系统互斥体的机制，因此在调用此构造函数重载时，最好为 initiallyOwned 指定 false 。 如果需要确定初始所有权， Mutex(Boolean, String, Boolean) 可以使用 构造函数。

此构造函数初始化表示 Mutex 命名系统互斥体的 对象。 可以创建表示同一命名系统互斥体的多个 Mutex 对象。

如果已创建具有访问控制安全性的命名互斥体，并且调用方没有 MutexRights.FullControl，则会引发异常。 若要打开仅具有同步线程活动所需的权限的现有命名互斥体，请参阅 OpenExisting 方法。

如果为 指定或为 name指定null空字符串，则会创建本地互斥体，就像调用构造函数一Mutex(Boolean)样。 在这种情况下， createdNew 始终 true为 。

由于它们是系统范围的，因此命名互斥体可用于协调跨进程边界的资源使用。

注意

在运行终端服务的服务器上，命名系统互斥体可以具有两个级别的可见性。 如果其名称以前缀 Global\开头，则互斥体在所有终端服务器会话中可见。 如果互斥体的名称以前缀 Local\开头，则互斥体仅在创建它的终端服务器会话中可见。 在这种情况下，服务器上的每个其他终端服务器会话中可以存在具有相同名称的单独互斥体。 如果在创建命名互斥体时未指定前缀，则它采用前缀 Local\。 在终端服务器会话中，名称仅因前缀而不同的两个互斥体是单独的互斥体，并且两者对终端服务器会话中的所有进程都可见。 也就是说，前缀名称和Global\Local\描述互斥体名称的范围相对于终端服务器会话，而不是相对于进程。

注意

默认情况下，命名互斥体不限于创建它的用户。 其他用户可能能够打开和使用互斥体，包括通过输入互斥体而不退出互斥来干扰互斥体。 在类似 Unix 的操作系统上，文件系统用于实现命名互斥体，其他用户可能能够以更重要的方式干扰命名互斥体。 在 Windows 上，若要限制对特定用户的访问，可以使用构造函数重载或在 MutexAcl 创建命名互斥体时传入 MutexSecurity 。 在类似于 Unix 的操作系统上，目前无法限制对命名互斥体的访问。 避免在可能有不受信任的用户运行代码的系统上使用没有访问限制的命名互斥体。

反斜杠 (\) 是互斥体名称中的保留字符。 请勿在互斥名称中使用反斜杠 (\) ，除非在终端服务器会话中使用互斥体的说明中所述。 否则，即使互斥体的名称表示现有文件，也可能引发 DirectoryNotFoundException。

另请参阅

• 托管线程
• Mutex

Mutex(Boolean, String, Boolean)

Source:

Mutex.cs

使用可指示调用线程是否应具有互斥体的初始所有权以及字符串是否为互斥体的名称的 Boolean 值和当线程返回时可指示调用线程是否已赋予互斥体的初始所有权的 Boolean 值初始化 Mutex 类的新实例。

public:
 Mutex(bool initiallyOwned, System::String ^ name, [Runtime::InteropServices::Out] bool % createdNew);

public Mutex (bool initiallyOwned, string? name, out bool createdNew);

new System.Threading.Mutex : bool * string * bool -> System.Threading.Mutex

Public Sub New (initiallyOwned As Boolean, name As String, ByRef createdNew As Boolean)

参数

initiallyOwned

Boolean

如果为 true，则给予调用线程已命名的系统互斥体的初始所属权（如果已命名的系统互斥体是通过此调用创建的）；否则为 false。

name

String

如果要与其他进程共享同步对象，则为名称；否则为 null 或空字符串。 该名称区分大小写。 反斜杠字符 (\) 是保留的，只能用于指定命名空间。 有关命名空间的详细信息，请参阅备注部分。 根据操作系统，名称可能会有进一步的限制。 例如，在基于 Unix 的操作系统上，排除命名空间后的名称必须是有效的文件名。

createdNew

Boolean

在此方法返回时，如果创建了局部互斥体（即，如果 name 为 null 或空字符串）或指定的命名系统互斥体，则包含布尔值 true；如果指定的命名系统互斥体已存在，则为 false。 此参数未经初始化即被传递。

例外

UnauthorizedAccessException

命名互斥体存在且具有访问控制安全性，但用户不具备 FullControl。

IOException

name 无效。 导致这种情况的原因有很多，包括操作系统可能会施加的一些限制，例如未知前缀或无效字符。 请注意，名称和常见前缀“Global\”和“Local\”区分大小写。

或

还有其他一些错误。 HResult 属性可能提供更多信息。

DirectoryNotFoundException

仅限 Windows：name 指定了未知命名空间。 有关详细信息，请参阅对象名称。

PathTooLongException

name 太长。 长度限制可能取决于操作系统或配置。

WaitHandleCannotBeOpenedException

无法创建具有提供的 name 的同步对象。 不同类型的同步对象可能具有相同的名称。

ArgumentException

仅限 .NET Framework：name 的长度超过 MAX_PATH（260 个字符）。

示例

下面的代码示例演示如何使用命名互斥体在进程或线程之间发出信号。 从两个或多个命令窗口运行此程序。 每个进程创建一个 Mutex 对象，该对象表示命名的互斥体“MyMutex”。 命名的 mutex 是一个系统对象。 在此示例中，它的生存期由表示它的对象的生存期 Mutex 限制。 命名互斥体在第一个进程创建其本地 Mutex 对象时创建，并在释放表示它的所有 Mutex 对象时销毁。 命名的 mutex 最初由第一个进程拥有。 第二个进程和任何后续进程等待早期进程释放命名的互斥体。

// This example shows how a named mutex is used to signal between
// processes or threads.
// Run this program from two (or more) command windows. Each process
// creates a Mutex object that represents the named mutex "MyMutex".
// The named mutex is a system object whose lifetime is bounded by the
// lifetimes of the Mutex objects that represent it. The named mutex
// is created when the first process creates its local Mutex; in this
// example, the named mutex is owned by the first process. The named 
// mutex is destroyed when all the Mutex objects that represent it
// have been released. 
// The second process (and any subsequent process) waits for earlier
// processes to release the named mutex.
using namespace System;
using namespace System::Threading;
int main()
{
   
   // Set this variable to false if you do not want to request 
   // initial ownership of the named mutex.
   bool requestInitialOwnership = true;
   bool mutexWasCreated;
   
   // Request initial ownership of the named mutex by passing
   // true for the first parameter. Only one system object named 
   // "MyMutex" can exist; the local Mutex object represents 
   // this system object. If "MyMutex" is created by this call,
   // then mutexWasCreated contains true; otherwise, it contains
   // false.
   Mutex^ m = gcnew Mutex( requestInitialOwnership, "MyMutex", mutexWasCreated );
   
   // This thread owns the mutex only if it both requested 
   // initial ownership and created the named mutex. Otherwise,
   // it can request the named mutex by calling WaitOne.
   if (  !(requestInitialOwnership && mutexWasCreated) )
   {
      Console::WriteLine(  "Waiting for the named mutex." );
      m->WaitOne();
   }

   
   // Once the process has gained control of the named mutex,
   // hold onto it until the user presses ENTER.
   Console::WriteLine(  "This process owns the named mutex. "
    "Press ENTER to release the mutex and exit." );
   Console::ReadLine();
   
   // Call ReleaseMutex to allow other threads to gain control
   // of the named mutex. If you keep a reference to the local
   // Mutex, you can call WaitOne to request control of the 
   // named mutex.
   m->ReleaseMutex();
}

// This example shows how a named mutex is used to signal between
// processes or threads.
// Run this program from two (or more) command windows. Each process
// creates a Mutex object that represents the named mutex "MyMutex".
// The named mutex is a system object whose lifetime is bounded by the
// lifetimes of the Mutex objects that represent it. The named mutex
// is created when the first process creates its local Mutex; in this
// example, the named mutex is owned by the first process. The named 
// mutex is destroyed when all the Mutex objects that represent it
// have been released. 
// The second process (and any subsequent process) waits for earlier
// processes to release the named mutex.

using System;
using System.Threading;

public class Test12
{
    public static void Main()
    {
        // Set this variable to false if you do not want to request 
        // initial ownership of the named mutex.
        bool requestInitialOwnership = true;
        bool mutexWasCreated;

        // Request initial ownership of the named mutex by passing
        // true for the first parameter. Only one system object named 
        // "MyMutex" can exist; the local Mutex object represents 
        // this system object. If "MyMutex" is created by this call,
        // then mutexWasCreated contains true; otherwise, it contains
        // false.
        Mutex m = new Mutex(requestInitialOwnership, 
                            "MyMutex", 
                            out mutexWasCreated);
        
        // This thread owns the mutex only if it both requested 
        // initial ownership and created the named mutex. Otherwise,
        // it can request the named mutex by calling WaitOne.
        if (!(requestInitialOwnership && mutexWasCreated))
        {
            Console.WriteLine("Waiting for the named mutex.");
            m.WaitOne();
        }

        // Once the process has gained control of the named mutex,
        // hold onto it until the user presses ENTER.
        Console.WriteLine("This process owns the named mutex. " +
            "Press ENTER to release the mutex and exit.");
        Console.ReadLine();

        // Call ReleaseMutex to allow other threads to gain control
        // of the named mutex. If you keep a reference to the local
        // Mutex, you can call WaitOne to request control of the 
        // named mutex.
        m.ReleaseMutex();
    }
}

' This example shows how a named mutex is used to signal between
' processes or threads.
' Run this program from two (or more) command windows. Each process
' creates a Mutex object that represents the named mutex "MyMutex".
' The named mutex is a system object whose lifetime is bounded by the
' lifetimes of the Mutex objects that represent it. The named mutex
' is created when the first process creates its local Mutex; in this
' example, the named mutex is owned by the first process. The named 
' mutex is destroyed when all the Mutex objects that represent it
' have been released. 
' The second process (and any subsequent process) waits for earlier
' processes to release the named mutex.

Imports System.Threading

Public Class Test
   
   <MTAThread> _
   Public Shared Sub Main()
      ' Set this variable to false if you do not want to request 
      ' initial ownership of the named mutex.
      Dim requestInitialOwnership As Boolean = True
      Dim mutexWasCreated As Boolean
      
      ' Request initial ownership of the named mutex by passing
      ' true for the first parameter. Only one system object named 
      ' "MyMutex" can exist; the local Mutex object represents 
      ' this system object. If "MyMutex" is created by this call,
      ' then mutexWasCreated contains true; otherwise, it contains
      ' false.
      Dim m As New Mutex(requestInitialOwnership, "MyMutex", _
          mutexWasCreated)
      
      ' This thread owns the mutex only if it both requested 
      ' initial ownership and created the named mutex. Otherwise,
      ' it can request the named mutex by calling WaitOne.
      If Not (requestInitialOwnership And mutexWasCreated) Then
         Console.WriteLine("Waiting for the named mutex.")
         m.WaitOne()
      End If
      
      ' Once the process has gained control of the named mutex,
      ' hold onto it until the user presses ENTER.
      Console.WriteLine("This process owns the named mutex. " _
          & "Press ENTER to release the mutex and exit.")
      Console.ReadLine()
      
      ' Call ReleaseMutex to allow other threads to gain control
      ' of the named mutex. If you keep a reference to the local
      ' Mutex, you can call WaitOne to request control of the 
      ' named mutex.
      m.ReleaseMutex()
   End Sub
End Class

注解

name可以使用 或 Local\ 作为前缀Global\来指定命名空间。 Global指定命名空间后，可以与系统上的任何进程共享同步对象。 如果指定了 Local 命名空间（如果未指定命名空间，这也是默认命名空间），则同步对象可以与同一会话中的进程共享。 在 Windows 上，会话是登录会话，服务通常在不同的非交互式会话中运行。 在类似 Unix 的操作系统上，每个 shell 都有自己的会话。 会话本地同步对象可能适合在具有父/子关系的进程之间进行同步，这些进程都在同一会话中运行。 有关 Windows 上的同步对象名称的详细信息，请参阅 对象名称。

如果提供了 ， name 并且命名空间中已存在请求类型的同步对象，则使用现有同步对象。 如果命名空间中已存在不同类型的同步对象， WaitHandleCannotBeOpenedException 则会引发 。 否则，将创建新的同步对象。

如果 name 不是 null 且 initiallyOwned 为 true，则仅当 在 调用后为 true 时createdNew，调用线程才拥有命名的互斥体。 否则，线程可以通过调用 WaitOne 方法请求互斥体。

此构造函数初始化表示 Mutex 命名系统互斥体的 对象。 可以创建表示同一命名系统互斥体的多个 Mutex 对象。

如果已使用访问控制安全性创建了命名互斥体，并且调用方没有 MutexRights.FullControl 权限，则会引发异常。 若要打开仅具有同步线程活动所需的权限的现有命名互斥体，请参阅 OpenExisting 方法。

如果为 指定或为 name指定null空字符串，则会创建本地互斥体，就像调用构造函数一Mutex(Boolean)样。 在这种情况下， createdNew 始终 true为 。

由于它们是系统范围的，因此命名互斥体可用于协调跨进程边界的资源使用。

注意

在运行终端服务的服务器上，命名系统互斥体可以具有两个级别的可见性。 如果其名称以前缀 Global\开头，则互斥体在所有终端服务器会话中可见。 如果互斥体的名称以前缀 Local\开头，则互斥体仅在创建它的终端服务器会话中可见。 在这种情况下，服务器上的每个其他终端服务器会话中可以存在具有相同名称的单独互斥体。 如果在创建命名互斥体时未指定前缀，则它采用前缀 Local\。 在终端服务器会话中，名称仅因前缀而不同的两个互斥体是单独的互斥体，并且两者对终端服务器会话中的所有进程都可见。 也就是说，前缀名称和Global\Local\描述互斥体名称的范围相对于终端服务器会话，而不是相对于进程。

注意

默认情况下，命名互斥体不限于创建它的用户。 其他用户可能能够打开和使用互斥体，包括通过输入互斥体而不退出互斥来干扰互斥体。 在类似 Unix 的操作系统上，文件系统用于实现命名互斥体，其他用户可能能够以更重要的方式干扰命名互斥体。 在 Windows 上，若要限制对特定用户的访问，可以使用构造函数重载或在 MutexAcl 创建命名互斥体时传入 MutexSecurity 。 在类似于 Unix 的操作系统上，目前无法限制对命名互斥体的访问。 避免在可能有不受信任的用户运行代码的系统上使用没有访问限制的命名互斥体。

反斜杠 (\) 是互斥体名称中的保留字符。 请勿在互斥名称中使用反斜杠 (\) ，除非在终端服务器会话中使用互斥体的说明中所述。 否则，即使互斥体的名称表示现有文件，也可能引发 DirectoryNotFoundException。

另请参阅

• 托管线程
• Mutex