AbandonedMutexException.MutexIndex AbandonedMutexException.MutexIndex AbandonedMutexException.MutexIndex AbandonedMutexException.MutexIndex Property

定义

获取导致异常的被放弃的互斥体的索引(如果已知的话)。Gets the index of the abandoned mutex that caused the exception, if known.

public:
 property int MutexIndex { int get(); };
public int MutexIndex { get; }
member this.MutexIndex : int
Public ReadOnly Property MutexIndex As Integer

属性值

传递给WaitAny方法Mutex的等待句柄数组中的索引 (表示被放弃的互斥体的对象); 如果无法确定被放弃的互斥体的索引, 则为-1。The index, in the array of wait handles passed to the WaitAny method, of the Mutex object that represents the abandoned mutex, or -1 if the index of the abandoned mutex could not be determined.

示例

下面的代码示例执行一个放弃五个互斥体的线程。The following code example executes a thread that abandons five mutexes. 放弃的 mutex 用于演示对WaitHandle.WaitOneWaitAnyWaitAll方法调用的影响。The abandoned mutexes are used to demonstrate the effects on the WaitHandle.WaitOne, WaitAny, and WaitAll method calls. 为该MutexIndex WaitAny调用显示属性的值。The value of the MutexIndex property is displayed for the WaitAny call.

备注

WaitAny的调用将被一个被放弃的 mutex 中断。The call to WaitAny is interrupted by one of the abandoned mutexes. 另一个AbandonedMutexException被放弃的互斥体仍可能会导致后续等待方法引发。The other abandoned mutex could still cause an AbandonedMutexException to be thrown by subsequent wait methods.

using namespace System;
using namespace System::Threading;

namespace SystemThreadingExample
{
    public ref class Example
    {
    private:
        static ManualResetEvent^ dummyEvent = 
            gcnew ManualResetEvent(false);
            
        static Mutex^ orphanMutex1 = gcnew Mutex;
        static Mutex^ orphanMutex2 = gcnew Mutex;
        static Mutex^ orphanMutex3 = gcnew Mutex;
        static Mutex^ orphanMutex4 = gcnew Mutex;
        static Mutex^ orphanMutex5 = gcnew Mutex;
        
    public:
        static void ProduceAbandonMutexException(void)
        {
            
            // Start a thread that grabs all five mutexes, and then
            // abandons them.
            Thread^ abandonThread = 
                gcnew Thread(gcnew ThreadStart(AbandonMutex));

            abandonThread->Start();
            
            // Make sure the thread is finished.
            abandonThread->Join();
            
            // Wait on one of the abandoned mutexes. The WaitOne
            // throws an AbandonedMutexException.
            try
            {
                orphanMutex1->WaitOne();
                Console::WriteLine("WaitOne succeeded.");
            }
            catch (AbandonedMutexException^ ex) 
            {
                Console::WriteLine("Exception in WaitOne: {0}", 
                    ex->Message);
            }
            finally
            {
                
                // Whether or not the exception was thrown, 
                // the current thread owns the mutex, and 
                // must release it.
                orphanMutex1->ReleaseMutex();
            }

            
            // Create an array of wait handles, consisting of one
            // ManualResetEvent and two mutexes, using two more of
            // the abandoned mutexes.
            array <WaitHandle^>^ waitFor = {dummyEvent, 
                orphanMutex2, orphanMutex3};
            
            // WaitAny returns when any of the wait handles in the 
            // array is signaled. Either of the two abandoned mutexes
            // satisfy the wait, but lower of the two index values is
            // returned by MutexIndex. Note that the Try block and
            // the Catch block obtain the index in different ways.
            try
            {
                int index = WaitHandle::WaitAny(waitFor);
                Console::WriteLine("WaitAny succeeded.");
                (safe_cast<Mutex^>(waitFor[index]))->ReleaseMutex();
            }
            catch (AbandonedMutexException^ ex) 
            {
                Console::WriteLine("Exception in WaitAny at index {0}"
                    "\r\n\tMessage: {1}", ex->MutexIndex, 
                    ex->Message);
                (safe_cast<Mutex^>(waitFor[ex->MutexIndex]))->
                    ReleaseMutex();
            }

            orphanMutex3->ReleaseMutex();
            
            // Use two more of the abandoned mutexes for the WaitAll 
            // call. WaitAll doesn't return until all wait handles 
            // are signaled, so the ManualResetEvent must be signaled 
            // by calling Set().
            dummyEvent->Set();
            waitFor[1] = orphanMutex4;
            waitFor[2] = orphanMutex5;
            
            // Because WaitAll requires all the wait handles to be
            // signaled, both mutexes must be released even if the
            // exception is thrown. Thus, the ReleaseMutex calls are 
            // placed in the Finally block. Again, MutexIndex returns
            // the lower of the two index values for the abandoned
            // mutexes.
            //  
            try
            {
                WaitHandle::WaitAll(waitFor);
                Console::WriteLine("WaitAll succeeded.");
            }
            catch (AbandonedMutexException^ ex) 
            {
                Console::WriteLine("Exception in WaitAny at index {0}"
                    "\r\n\tMessage: {1}", ex->MutexIndex, 
                    ex->Message);
            }
            finally
            {
                orphanMutex4->ReleaseMutex();
                orphanMutex5->ReleaseMutex();
            }

        }


    private:
        [MTAThread]
        static void AbandonMutex()
        {
            orphanMutex1->WaitOne();
            orphanMutex2->WaitOne();
            orphanMutex3->WaitOne();
            orphanMutex4->WaitOne();
            orphanMutex5->WaitOne();
            Console::WriteLine(
                "Thread exits without releasing the mutexes.");
        }
    };   
}

//Entry point of example application
[MTAThread]
int main(void)
{
    SystemThreadingExample::Example::ProduceAbandonMutexException();
}

// This code example produces the following output:
// Thread exits without releasing the mutexes.
// Exception in WaitOne: The wait completed due to an abandoned mutex.
// Exception in WaitAny at index 1
//         Message: The wait completed due to an abandoned mutex.
// Exception in WaitAll at index -1
//         Message: The wait completed due to an abandoned mutex.


using System;
using System.Threading;

public class Example
{
    private static ManualResetEvent _dummy = new ManualResetEvent(false);

    private static Mutex _orphan1 = new Mutex();
    private static Mutex _orphan2 = new Mutex();
    private static Mutex _orphan3 = new Mutex();
    private static Mutex _orphan4 = new Mutex();
    private static Mutex _orphan5 = new Mutex();

    [MTAThread]
    public static void Main()
    {
        // Start a thread that takes all five mutexes, and then
        // ends without releasing them.
        //
        Thread t = new Thread(new ThreadStart(AbandonMutex));
        t.Start();
        // Make sure the thread is finished.
        t.Join();

        // Wait on one of the abandoned mutexes. The WaitOne returns
        // immediately, because its wait condition is satisfied by
        // the abandoned mutex, but on return it throws
        // AbandonedMutexException.
        try
        {
            _orphan1.WaitOne();
            Console.WriteLine("WaitOne succeeded.");
        }
        catch(AbandonedMutexException ex)
        {
            Console.WriteLine("Exception on return from WaitOne." +
                "\r\n\tMessage: {0}", ex.Message);
        }
        finally
        {
            // Whether or not the exception was thrown, the current
            // thread owns the mutex, and must release it.
            //
            _orphan1.ReleaseMutex();
        }

        // Create an array of wait handles, consisting of one
        // ManualResetEvent and two mutexes, using two more of the
        // abandoned mutexes.
        WaitHandle[] waitFor = {_dummy, _orphan2, _orphan3};

        // WaitAny returns when any of the wait handles in the 
        // array is signaled, so either of the two abandoned mutexes
        // satisfy its wait condition. On returning from the wait,
        // WaitAny throws AbandonedMutexException. The MutexIndex
        // property returns the lower of the two index values for 
        // the abandoned mutexes. Note that the Try block and the
        // Catch block obtain the index in different ways.
        //  
        try
        {
            int index = WaitHandle.WaitAny(waitFor);
            Console.WriteLine("WaitAny succeeded.");

            // The current thread owns the mutex, and must release
            // it.
            Mutex m = waitFor[index] as Mutex;
            if (m != null) m.ReleaseMutex();
        }
        catch(AbandonedMutexException ex)
        {
            Console.WriteLine("Exception on return from WaitAny at index {0}." +
                "\r\n\tMessage: {1}", ex.MutexIndex, ex.Message);

            // Whether or not the exception was thrown, the current
            // thread owns the mutex, and must release it.
            //
            if (ex.Mutex != null) ex.Mutex.ReleaseMutex();
        }

        // Use two more of the abandoned mutexes for the WaitAll call.
        // WaitAll doesn't return until all wait handles are signaled,
        // so the ManualResetEvent must be signaled by calling Set().
        _dummy.Set();
        waitFor[1] = _orphan4;
        waitFor[2] = _orphan5;

        // The signaled event and the two abandoned mutexes satisfy
        // the wait condition for WaitAll, but on return it throws
        // AbandonedMutexException. For WaitAll, the MutexIndex
        // property is always -1 and the Mutex property is always
        // null.
        //  
        try
        {
            WaitHandle.WaitAll(waitFor);
            Console.WriteLine("WaitAll succeeded.");
        }
        catch(AbandonedMutexException ex)
        {
            Console.WriteLine("Exception on return from WaitAll. MutexIndex = {0}." +
                "\r\n\tMessage: {1}", ex.MutexIndex, ex.Message);
        }
        finally
        {
            // Whether or not the exception was thrown, the current
            // thread owns the mutexes, and must release them.
            //
            _orphan4.ReleaseMutex();
            _orphan5.ReleaseMutex();
        }
    }

    [MTAThread]
    public static void AbandonMutex()
    {
        _orphan1.WaitOne();
        _orphan2.WaitOne();
        _orphan3.WaitOne();
        _orphan4.WaitOne();
        _orphan5.WaitOne();
        // Abandon the mutexes by exiting without releasing them.
        Console.WriteLine("Thread exits without releasing the mutexes.");
    }
}

/* This code example produces the following output:

Thread exits without releasing the mutexes.
Exception on return from WaitOne.
        Message: The wait completed due to an abandoned mutex.
Exception on return from WaitAny at index 1.
        Message: The wait completed due to an abandoned mutex.
Exception on return from WaitAll. MutexIndex = -1.
        Message: The wait completed due to an abandoned mutex.
 */
Option Explicit
Imports System.Threading

Public Class Example
    Private Shared _dummy As New ManualResetEvent(False)

    Private Shared _orphan1 As New Mutex()
    Private Shared _orphan2 As New Mutex()
    Private Shared _orphan3 As New Mutex()
    Private Shared _orphan4 As New Mutex()
    Private Shared _orphan5 As New Mutex()

    <MTAThread> _
    Public Shared Sub Main()
        ' Start a thread that takes all five mutexes, and then
        ' ends without releasing them.
        '
        Dim t As New Thread(AddressOf AbandonMutex)
        t.Start()
        ' Make sure the thread is finished.
        t.Join()

        ' Wait on one of the abandoned mutexes. The WaitOne returns
        ' immediately, because its wait condition is satisfied by
        ' the abandoned mutex, but on return it throws
        ' AbandonedMutexException.
        Try
            _orphan1.WaitOne()
            Console.WriteLine("WaitOne succeeded.")
        Catch ex As AbandonedMutexException
            Console.WriteLine("Exception on return from WaitOne." _
                & vbCrLf & vbTab & "Message: " _
                & ex.Message) 
        Finally
            ' Whether or not the exception was thrown, the current
            ' thread owns the mutex, and must release it.
            '
            _orphan1.ReleaseMutex()
        End Try

        ' Create an array of wait handles, consisting of one
        ' ManualResetEvent and two mutexes, using two more of the
        ' abandoned mutexes.
        Dim waitFor(2) As WaitHandle
        waitFor(0) = _dummy
        waitFor(1) = _orphan2
        waitFor(2) = _orphan3

        ' WaitAny returns when any of the wait handles in the 
        ' array is signaled, so either of the two abandoned mutexes
        ' satisfy its wait condition. On returning from the wait,
        ' WaitAny throws AbandonedMutexException. The MutexIndex
        ' property returns the lower of the two index values for 
        ' the abandoned mutexes. Note that the Try block and the
        ' Catch block obtain the index in different ways.
        '  
        Try
            Dim index As Integer = WaitHandle.WaitAny(waitFor)
            Console.WriteLine("WaitAny succeeded.")

            Dim m As Mutex = TryCast(waitFor(index), Mutex)

            ' The current thread owns the mutex, and must release
            ' it.
            If m IsNot Nothing Then m.ReleaseMutex()
        Catch ex As AbandonedMutexException
            Console.WriteLine("Exception on return from WaitAny at index " _
                & ex.MutexIndex & "." _
                & vbCrLf & vbTab & "Message: " _
                & ex.Message) 

            ' Whether or not the exception was thrown, the current
            ' thread owns the mutex, and must release it.
            '
            If ex.Mutex IsNot Nothing Then ex.Mutex.ReleaseMutex()            
        End Try

        ' Use two more of the abandoned mutexes for the WaitAll call.
        ' WaitAll doesn't return until all wait handles are signaled,
        ' so the ManualResetEvent must be signaled by calling Set(). 
        _dummy.Set()
        waitFor(1) = _orphan4
        waitFor(2) = _orphan5

        ' The signaled event and the two abandoned mutexes satisfy
        ' the wait condition for WaitAll, but on return it throws
        ' AbandonedMutexException. For WaitAll, the MutexIndex
        ' property is always -1 and the Mutex property is always
        ' Nothing.
        '  
        Try
            WaitHandle.WaitAll(waitFor)
            Console.WriteLine("WaitAll succeeded.")
        Catch ex As AbandonedMutexException
            Console.WriteLine("Exception on return from WaitAll. MutexIndex = " _
                & ex.MutexIndex & "." _
                & vbCrLf & vbTab & "Message: " _
                & ex.Message) 
        Finally
            ' Whether or not the exception was thrown, the current
            ' thread owns the mutexes, and must release them.
            '
            CType(waitFor(1), Mutex).ReleaseMutex()
            CType(waitFor(2), Mutex).ReleaseMutex()
        End Try
    End Sub

    <MTAThread> _
    Public Shared Sub AbandonMutex()
        _orphan1.WaitOne()
        _orphan2.WaitOne()
        _orphan3.WaitOne()
        _orphan4.WaitOne()
        _orphan5.WaitOne()
        ' Abandon the mutexes by exiting without releasing them.
        Console.WriteLine("Thread exits without releasing the mutexes.")
    End Sub
End Class

' This code example produces the following output:
'
'Thread exits without releasing the mutexes.
'Exception on return from WaitOne.
'        Message: The wait completed due to an abandoned mutex.
'Exception on return from WaitAny at index 1.
'        Message: The wait completed due to an abandoned mutex.
'Exception on return from WaitAll. MutexIndex = -1.
'        Message: The wait completed due to an abandoned mutex.

注解

如果对WaitHandle.WaitAny方法的调用引发了异常, 则此属性将返回被传递到WaitAnyWaitHandle对象数组中具有最低索引的被放弃的互斥体的索引; 如果无法识别被放弃的互斥体, 则返回-1。If the exception is thrown on a call to the WaitHandle.WaitAny method, this property returns the index of the abandoned mutex with the lowest index in the array of WaitHandle objects that was passed to WaitAny, or -1 if the abandoned mutex could not be identified. 如果对WaitOneWaitAll的调用引发了异常, 则此属性始终返回-1。If the exception is thrown on a call to WaitOne or WaitAll, this property always returns -1.

适用于

另请参阅