ServiceBase.OnPause Method (System.ServiceProcess)

OnPause Method

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Microsoft Visual Studio 2005/.NET Framework 2.0

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.NET Framework Class Library

ServiceBase.OnPause Method

When implemented in a derived class, executes when a Pause command is sent to the service by the Service Control Manager (SCM). Specifies actions to take when a service pauses.

Namespace: System.ServiceProcess
Assembly: System.ServiceProcess (in system.serviceprocess.dll)

Syntax

Visual Basic (Declaration)

Protected Overridable Sub OnPause

Visual Basic (Usage)

Me.OnPause

protected virtual void OnPause ()

C++

protected:
virtual void OnPause ()

protected void OnPause ()

JScript

protected function OnPause ()

Remarks

Use OnPause to specify the processing that occurs when the service receives a Pause command. OnPause is expected to be overridden when the CanPauseAndContinue property is true.

When you continue a paused service (either through the Services add-in or programmatically), the OnContinue processing is run, and the service becomes active again.

The Pause command only allows your application to react to a specific event. OnPause does nothing to the service that you do not define it to do.

Sending a Pause request to the service can conserve system resources because Pause need not release all system resources. For example, if threads have been opened by the process, pausing a service rather than stopping it can allow the threads to remain open, obviating the need to reallocate them when the service continues. If you define Pause to release all system resources, it behaves like a Stop command.

Set CanPauseAndContinue to true, and override OnPause and OnContinue to specify the processing that should occur when the SCM passes a Pause or Continue request to your service. OnContinue should be implemented to undo the processing in OnPause.

If CanPauseAndContinue is false, the SCM will not pass Pause or Continue requests to the service, so the OnPause and OnContinue methods will not be called even if implemented. In the SCM, the Pause and Continue controls are disabled when CanPauseAndContinue is false.

Example

The following example shows an implementation of the OnPause method for a service class derived from ServiceBase. This code example is part of a larger example provided for the ServiceBase class.

Visual Basic

    ' Pause the service.
    Protected Overrides Sub OnPause()
        ' Pause the worker thread.
        If Not (workerThread Is Nothing) AndAlso workerThread.IsAlive AndAlso (workerThread.ThreadState And System.Threading.ThreadState.Suspended Or System.Threading.ThreadState.SuspendRequested) = 0 Then
#If LOGEVENTS Then
            System.Diagnostics.EventLog.WriteEntry("SimpleService.OnPause", DateTime.Now.ToLongTimeString() + _
                " - Pausing the service worker thread.")
#End If

            pause.Reset()
            Thread.Sleep(5000)
        End If

        If Not (workerThread Is Nothing) Then
#If LOGEVENTS Then
            System.Diagnostics.EventLog.WriteEntry("SimpleService.OnPause", DateTime.Now.ToLongTimeString() + _
                " OnPause - Worker thread state = " + workerThread.ThreadState.ToString())
#End If
        End If

    End Sub 'OnPause

        // Pause the service.
        protected override void OnPause()
        {
            // Pause the worker thread.
            if ((workerThread != null) &&
                (workerThread.IsAlive) &&
                ((workerThread.ThreadState &
                 (System.Threading.ThreadState.Suspended | System.Threading.ThreadState.SuspendRequested)) == 0))
            {
#if LOGEVENTS
                EventLog.WriteEntry("SimpleService.OnPause", DateTime.Now.ToLongTimeString() +
                    " - Pausing the service worker thread.");
#endif

                pause.Reset();
                Thread.Sleep(5000);
            }

            if (workerThread != null)
            {
#if LOGEVENTS
                EventLog.WriteEntry("SimpleService.OnPause", DateTime.Now.ToLongTimeString() +
                    " OnPause - Worker thread state = " +
                    workerThread.ThreadState.ToString());
#endif
            }
        }

C++

    // Pause the service.
protected:
    virtual void OnPause() override
    {
        // Pause the worker thread.
        if ( (workerThread != nullptr) && (workerThread->IsAlive) && ((workerThread->ThreadState & (System::Threading::ThreadState::Suspended | System::Threading::ThreadState::SuspendRequested)) == (System::Threading::ThreadState)0) )
        {
            Trace::WriteLine( DateTime::Now.ToLongTimeString() + " - Suspending the service worker thread.", "OnPause" );
            workerThread->Suspend();
        }

        if ( workerThread != nullptr )
        {
            Trace::WriteLine( DateTime::Now.ToLongTimeString() + " - Worker thread state = " + workerThread->ThreadState.ToString(), "OnPause" );
        }
    }

.NET Framework Security

Full trust for the immediate caller. This member cannot be used by partially trusted code. For more information, see .

Platforms

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

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.

Version Information

.NET Framework

Supported in: 2.0, 1.1, 1.0

Reference

ServiceBase Class
ServiceBase Members
System.ServiceProcess Namespace
CanPauseAndContinue
OnContinue
OnPowerEvent
OnShutdown
OnStart
OnStop
OnCustomCommand