AbandonedMutexException.MutexIndex Proprietà
Definizione
Importante
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Ottiene l'indice del mutex abbandonato che ha causato l'eccezione, se noto.
public:
property int MutexIndex { int get(); };public int MutexIndex { get; }member this.MutexIndex : intPublic ReadOnly Property MutexIndex As IntegerValore della proprietà
Indice, nella matrice di handle di attesa passati al WaitAny metodo, dell'oggetto Mutex che rappresenta il mutex abbandonato o -1 se non è stato possibile determinare l'indice del mutex abbandonato.
Esempio
Nell'esempio di codice seguente viene eseguito un thread che abbandona cinque mutex. I mutex abbandonati vengono usati per illustrare gli effetti sulle WaitHandle.WaitOnechiamate di metodo , WaitAnye WaitAll . Il valore della MutexIndex proprietà viene visualizzato per la WaitAny chiamata.
Nota
La chiamata a WaitAny viene interrotta da uno dei mutex abbandonati. L'altro mutex abbandonato potrebbe comunque causare un'origine AbandonedMutexException da parte dei metodi di attesa successivi.
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.
Commenti
Se l'eccezione viene generata su una chiamata al WaitHandle.WaitAny metodo, questa proprietà restituisce l'indice del mutex abbandonato con l'indice più basso nella matrice di WaitHandle oggetti passati a WaitAnyo -1 se non è stato possibile identificare il mutex abbandonato. Se l'eccezione viene generata in una chiamata a WaitOne o WaitAll, questa proprietà restituisce sempre -1.
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