AbandonedMutexException.MutexIndex Vlastnost

public:
 property int MutexIndex { int get(); };

public int MutexIndex { get; }

member this.MutexIndex : int

Public ReadOnly Property MutexIndex As Integer

Hodnota vlastnosti

Index v poli obslužných rutin čekání předaných WaitAny metodě objektu Mutex , který představuje opuštěný mutex, nebo -1, pokud index opuštěného mutexu nelze určit.

Příklady

Následující příklad kódu spustí vlákno, které opustí pět mutexů. Opuštěné mutexy se používají k demonstraci účinků na WaitHandle.WaitOnevolání metody , WaitAnya WaitAll . Pro volání se MutexIndex zobrazí WaitAny hodnota vlastnosti.

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.

Poznámky

Pokud je při volání WaitHandle.WaitAny metody vyvolána výjimka, vrátí tato vlastnost index opuštěného mutexu s nejnižším indexem v poli WaitHandle objektů, které byly předány WaitAny, nebo -1, pokud nelze identifikovat opuštěný mutex. Pokud dojde k výjimce při volání WaitOne nebo WaitAll, vrátí tato vlastnost vždy hodnotu -1.

Platí pro

Viz také

• Mutex
• Mutex