AbandonedMutexException クラス

.NET Framework クラス ライブラリ リファレンス

AbandonedMutexException クラス

メモ : このクラスは、.NET Framework version 2.0 で新しく追加されたものです。

スレッドが、別のスレッドが解放せずに終了することによって放棄した Mutex オブジェクトを取得したときにスローされる例外。

名前空間: System.Threading
アセンブリ: mscorlib (mscorlib.dll 内)
構文

Visual Basic (宣言)

<SerializableAttribute> _
<ComVisibleAttribute(False)> _
Public Class AbandonedMutexException
    Inherits SystemException

Visual Basic (使用法)

Dim instance As AbandonedMutexException

C#

[SerializableAttribute] 
[ComVisibleAttribute(false)] 
public class AbandonedMutexException : SystemException

C++

[SerializableAttribute] 
[ComVisibleAttribute(false)] 
public ref class AbandonedMutexException :
 public SystemException

J#

/** @attribute SerializableAttribute() */ 
/** @attribute ComVisibleAttribute(false) */ 
public class AbandonedMutexException extends
 SystemException

JScript

SerializableAttribute 
ComVisibleAttribute(false) 
public class AbandonedMutexException extends
 SystemException

解説

スレッドがミューテックスを放棄すると、そのミューテックスを取得した次のスレッドで例外がスローされます。スレッドがミューテックスを取得するのは、スレッドが既にミューテックスを待機していた場合、または、放棄された後のミューテックスに入った場合です。

放棄されたミューテックスは、深刻なプログラミング エラーの存在を意味します。スレッドがミューテックスを解放せずに終了すると、ミューテックスによって保護されるデータ構造の状態に不整合が生じることがあります。.NET Framework Version 2.0 より前のバージョンでは、ミューテックスの放棄によって待機が完了した場合に例外がスローされないため、このような問題を発見することは困難でした。詳細については、Mutex クラスのトピックを参照してください。

データ構造の整合性を検証できる場合、ミューテックスの所有権を要求する次のスレッドがこの例外を処理して続行できます。

使用例

5 つのミューテックスを放棄するスレッドを実行し、それによって WaitOne、WaitAny、および WaitAll の各メソッドがどのような影響を受けるかを示すコード例を次に示します。MutexIndex プロパティの値は、WaitAny の呼び出しに対して表示されています。

メモ
WaitAny メソッドの呼び出しは、放棄されたミューテックスの 1 つによって中断されます。また、放棄された他のミューテックスにより、後続の待機メソッドで AbandonedMutexException がスローされる可能性もあります。

Visual Basic

Option Explicit
Imports System
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.

C#

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.
 */

C++

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.

J#

import System.*;
import 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();

    /** @attribute MTAThread()
     */
    public static void main(String[]
 args)
    {
        // Start a thread that takes all five mutexes, and then
        // ends without releasing them.
        //
        System.Threading.Thread t = new System.Threading.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.get_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
        // ManualReset_Event 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.");
            if (waitFor.get_Item(index) instanceof Mutex) {
                ((Mutex)(waitFor.get_Item(index))).ReleaseMutex();
            }
        }
        catch (AbandonedMutexException ex) {
            Console.WriteLine("Exception on return from WaitAny
 at index {0}" 
                + "\r\n\tMessage: {1}", (Int32)ex.get_MutexIndex(),
                ex.get_Message());

            // Whether or not the exception was thrown, the current
            // thread owns the mutex, and must release it.
            //
            if (ex.get_Mutex() != null) ex.get_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 ManualReset_Event must be signaled by calling set_().
        dummy.Set();
        waitFor.set_Item(1, orphan4);
        waitFor.set_Item(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 WaitAny
 at index {0}" 
                + "\r\n\tMessage: {1}", (Int32)ex.get_MutexIndex(),
                ex.get_Message());
        }
        finally {
            // Whether or not the exception was thrown, the current
            // thread owns the mutexes, and must release them.
            //
            orphan4.ReleaseMutex();
            orphan5.ReleaseMutex();
        }
    } //main

    /** @attribute 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.");
    } //AbandonMutex
} //Example

/* 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.
 */

継承階層

System.Object
   System.Exception
     System.SystemException
      System.Threading.AbandonedMutexException

スレッド セーフ

この型の public static (Visual Basic では Shared) メンバはすべて、スレッド セーフです。インスタンス メンバの場合は、スレッド セーフであるとは限りません。

プラットフォーム

Windows 98, Windows 2000 SP4, Windows Millennium Edition, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

開発プラットフォームの中には、.NET Framework によってサポートされていないバージョンがあります。サポートされているバージョンについては、「システム要件」を参照してください。

バージョン情報

.NET Framework
サポート対象 : 2.0

参照

関連項目
AbandonedMutexException メンバ
System.Threading 名前空間
Mutex
その他の技術情報
ミューテックス