How to handle SIGTERM from different OS(Linux/Windows) - c#

I created an ConsoleEventHandler based on the following link described: https://www.meziantou.net/detecting-console-closing-in-dotnet.htm
It works perfectly for me. Currently I wish it can handle SIGTERM from both Windows and Linux. Does anybody has some clue about how to optimize it in C#? The following code needs to be optimized in two parts:
can load Kernel32 in docker. Currently it fails in "System.DllNotFoundException: Unable to load shared library 'Kernel32' or one of its dependencies. "
Support linux system;
The source code:
class Program
{
// https://msdn.microsoft.com/fr-fr/library/windows/desktop/ms686016.aspx
[DllImport("Kernel32")]
private static extern bool SetConsoleCtrlHandler(SetConsoleCtrlEventHandler handler, bool add);
// https://msdn.microsoft.com/fr-fr/library/windows/desktop/ms683242.aspx
private delegate bool SetConsoleCtrlEventHandler(CtrlType sig);
private enum CtrlType
{
CTRL_C_EVENT = 0,
CTRL_BREAK_EVENT = 1,
CTRL_CLOSE_EVENT = 2,
CTRL_LOGOFF_EVENT = 5,
CTRL_SHUTDOWN_EVENT = 6
}
static void Main(string[] args)
{
// Register the handler
SetConsoleCtrlHandler(Handler, true);
// Wait for the event
while (true)
{
Thread.Sleep(50);
}
}
private static bool Handler(CtrlType signal)
{
switch (signal)
{
case CtrlType.CTRL_BREAK_EVENT:
case CtrlType.CTRL_C_EVENT:
case CtrlType.CTRL_LOGOFF_EVENT:
case CtrlType.CTRL_SHUTDOWN_EVENT:
case CtrlType.CTRL_CLOSE_EVENT:
Console.WriteLine("Closing");
// TODO Cleanup resources
Environment.Exit(0);
return false;
default:
return false;
}
}
}

Not sure if you still need an answer for it, but you could either go for any solution mentioned here:
Detect when console application is closing/killed?
Or you could use the Console.CancelKeyPress and AppDomain.CurrentDomain.ProcessExit Events. Both are working on Linux. Cheers!

Related

How to do gracefully shutdown on dotnet with docker?

Is there a way to gracefully shut-down a DOTNET CORE application which is running in DOCKER? If yes, which event I should listen?
All I want is upon cancellation request I would like to pass my cancellation token/s to current methods and postpone the shut-down while they are working.
Looking for a sample code, reference link etc. which are relevant to dotnet core and not generic info
UPDATE
This question is not a duplicate of docker container exits immediately even with Console.ReadLine() in a .net core console application because I'm not having an immediate exit issue. I need to tap into event something like Windows.SystemsEvents.SessionEnding and relying on Console.CancelKeyPress and/or implementing WebHostBuilder() doesn't fit the bill.
In .NET Core 2.0, you can use the AppDomain.CurrentDomain.ProcessExit event, which works fine on Linux in Docker. AssemblyLoadContext.Default.Unloading probably works as well, even before .NET Core 2.0.
System.Console has an event called CancelKeyPress. I believe this is fired when a sigint event is passed into dotnet.
System.Console.CancelKeyPress += (s,e) => { /* do something here */};
Using 2.0.0-preview2-006497 I did some testing, and now the AssemblyLoadContext.Default.Unloading is fired when Docker sends a SIGTERM/SIGINT to the container.
Example code looks like:
System.Runtime.Loader.AssemblyLoadContext.Default.Unloading += ctx =>
{
// code here...
};
See also this issue for some details: https://github.com/aspnet/Hosting/issues/870
If your container is running in Linux then Loader.AssemblyLoadContext.Default.Unloading works since it can trap the SIGTERM signal, however Windows do not have the equivalent mechanism for this(dotnet issue). Here's an answer to handle shutdown notification in Windows by using SetConsoleCtrlHandler originally from gist
namespace Routeguide
{
using System;
using System.Threading;
...
class Program
{
[DllImport("Kernel32")]
internal static extern bool SetConsoleCtrlHandler(HandlerRoutine handler, bool Add);
internal delegate bool HandlerRoutine(CtrlTypes ctrlType);
internal enum CtrlTypes
{
CTRL_C_EVENT = 0,
CTRL_BREAK_EVENT,
CTRL_CLOSE_EVENT,
CTRL_LOGOFF_EVENT = 5,
CTRL_SHUTDOWN_EVENT
}
static void Main(string[] args)
{
// do the server starting code
Start();
....
var shutdown = new ManualResetEvent(false);
var complete = new ManualResetEventSlim();
var hr = new HandlerRoutine(type =>
{
Log.Logger.Information($"ConsoleCtrlHandler got signal: {type}");
shutdown.Set();
complete.Wait();
return false;
});
SetConsoleCtrlHandler(hr, true);
Console.WriteLine("Waiting on handler to trigger...");
shutdown.WaitOne();
Console.WriteLine("Stopping server...");
// do the server stopping code
Stop();
complete.Set();
GC.KeepAlive(hr);
}
}
}

How can a .NET process determine whether it is being run as a windows service? [duplicate]

I am currently writing a little bootstrap code for a service that can be run in the console. It essentially boils down to calling the OnStart() method instead of using the ServiceBase to start and stop the service (because it doesn't run the application if it isn't installed as a service and makes debugging a nightmare).
Right now I am using Debugger.IsAttached to determine if I should use ServiceBase.Run or [service].OnStart, but I know that isn't the best idea because some times end users want to run the service in a console (to see the output etc. realtime).
Any ideas on how I could determine if the Windows service controller started 'me', or if the user started 'me' in the console? Apparantly Environment.IsUserInteractive is not the answer. I thought about using commandline args, but that seems 'dirty'.
I could always see about a try-catch statement around ServiceBase.Run, but that seems dirty. Edit: Try catch doesn't work.
I have a solution: putting it up here for all the other interested stackers:
public void Run()
{
if (Debugger.IsAttached || Environment.GetCommandLineArgs().Contains<string>("-console"))
{
RunAllServices();
}
else
{
try
{
string temp = Console.Title;
ServiceBase.Run((ServiceBase[])ComponentsToRun);
}
catch
{
RunAllServices();
}
}
} // void Run
private void RunAllServices()
{
foreach (ConsoleService component in ComponentsToRun)
{
component.Start();
}
WaitForCTRLC();
foreach (ConsoleService component in ComponentsToRun)
{
component.Stop();
}
}
EDIT: There was another question on StackOverflow where the guy had problems with the Environment.CurrentDirectory being "C:\Windows\System32" looks like that may be the answer. I will test today.
Another workaround.. so can run as WinForm or as windows service
var backend = new Backend();
if (Environment.UserInteractive)
{
backend.OnStart();
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
Application.Run(new Fronend(backend));
backend.OnStop();
}
else
{
var ServicesToRun = new ServiceBase[] {backend};
ServiceBase.Run(ServicesToRun);
}
I usually flag my Windows service as a console application which takes a command line parameter of "-console" to run using a console, otherwise it runs as a service. To debug you just set the command line parameters in the project options to "-console" and you're off!
This makes debugging nice and easy and means that the app functions as a service by default, which is what you'll want.
What works for me:
The class doing the actual service work is running in a separate thread.
This thread is started from within the OnStart() method, and stopped from OnStop().
The decision between service and console mode depends on Environment.UserInteractive
Sample code:
class MyService : ServiceBase
{
private static void Main()
{
if (Environment.UserInteractive)
{
startWorkerThread();
Console.WriteLine ("====== Press ENTER to stop threads ======");
Console.ReadLine();
stopWorkerThread() ;
Console.WriteLine ("====== Press ENTER to quit ======");
Console.ReadLine();
}
else
{
Run (this) ;
}
}
protected override void OnStart(string[] args)
{
startWorkerThread();
}
protected override void OnStop()
{
stopWorkerThread() ;
}
}
Like Ash, I write all actual processing code in a separate class library assembly, which was then referenced by the windows service executable, as well as a console app.
However, there are occasions when it is useful to know if the class library is running in the context of the service executable or the console app. The way I do this is to reflect on the base class of the hosting app. (Sorry for the VB, but I imagine that the following could be c#-ified fairly easily):
Public Class ExecutionContext
''' <summary>
''' Gets a value indicating whether the application is a windows service.
''' </summary>
''' <value>
''' <c>true</c> if this instance is service; otherwise, <c>false</c>.
''' </value>
Public Shared ReadOnly Property IsService() As Boolean
Get
' Determining whether or not the host application is a service is
' an expensive operation (it uses reflection), so we cache the
' result of the first call to this method so that we don't have to
' recalculate it every call.
' If we have not already determined whether or not the application
' is running as a service...
If IsNothing(_isService) Then
' Get details of the host assembly.
Dim entryAssembly As Reflection.Assembly = Reflection.Assembly.GetEntryAssembly
' Get the method that was called to enter the host assembly.
Dim entryPoint As System.Reflection.MethodInfo = entryAssembly.EntryPoint
' If the base type of the host assembly inherits from the
' "ServiceBase" class, it must be a windows service. We store
' the result ready for the next caller of this method.
_isService = (entryPoint.ReflectedType.BaseType.FullName = "System.ServiceProcess.ServiceBase")
End If
' Return the cached result.
Return CBool(_isService)
End Get
End Property
Private Shared _isService As Nullable(Of Boolean) = Nothing
#End Region
End Class
Jonathan, not exactly an answer to your question, but I've just finished writing a windows service and also noted the difficulty with debugging and testing.
Solved it by simply writing all actual processing code in a separate class library assembly, which was then referenced by the windows service executable, as well as a console app and a test harness.
Apart from basic timer logic, all more complex processing happened in the common assembly and could be tested/run on demand incredibly easily.
I have modified the ProjectInstaller to append the command-line argument parameter /service, when it is being installed as service:
static class Program
{
static void Main(string[] args)
{
if (Array.Exists(args, delegate(string arg) { return arg == "/install"; }))
{
System.Configuration.Install.TransactedInstaller ti = null;
ti = new System.Configuration.Install.TransactedInstaller();
ti.Installers.Add(new ProjectInstaller());
ti.Context = new System.Configuration.Install.InstallContext("", null);
string path = System.Reflection.Assembly.GetExecutingAssembly().Location;
ti.Context.Parameters["assemblypath"] = path;
ti.Install(new System.Collections.Hashtable());
return;
}
if (Array.Exists(args, delegate(string arg) { return arg == "/uninstall"; }))
{
System.Configuration.Install.TransactedInstaller ti = null;
ti = new System.Configuration.Install.TransactedInstaller();
ti.Installers.Add(new ProjectInstaller());
ti.Context = new System.Configuration.Install.InstallContext("", null);
string path = System.Reflection.Assembly.GetExecutingAssembly().Location;
ti.Context.Parameters["assemblypath"] = path;
ti.Uninstall(null);
return;
}
if (Array.Exists(args, delegate(string arg) { return arg == "/service"; }))
{
ServiceBase[] ServicesToRun;
ServicesToRun = new ServiceBase[] { new MyService() };
ServiceBase.Run(ServicesToRun);
}
else
{
Console.ReadKey();
}
}
}
The ProjectInstaller.cs is then modified to override a OnBeforeInstall() and OnBeforeUninstall()
[RunInstaller(true)]
public partial class ProjectInstaller : Installer
{
public ProjectInstaller()
{
InitializeComponent();
}
protected virtual string AppendPathParameter(string path, string parameter)
{
if (path.Length > 0 && path[0] != '"')
{
path = "\"" + path + "\"";
}
path += " " + parameter;
return path;
}
protected override void OnBeforeInstall(System.Collections.IDictionary savedState)
{
Context.Parameters["assemblypath"] = AppendPathParameter(Context.Parameters["assemblypath"], "/service");
base.OnBeforeInstall(savedState);
}
protected override void OnBeforeUninstall(System.Collections.IDictionary savedState)
{
Context.Parameters["assemblypath"] = AppendPathParameter(Context.Parameters["assemblypath"], "/service");
base.OnBeforeUninstall(savedState);
}
}
This thread is really old, but I thought I would throw my solution out there. Quite simply, to handle this type of situation, I built a "service harness" that is used in both the console and Windows service cases. As above, most of the logic is contained in a separate library, but this is more for testing and "linkability".
The attached code by no means represents the "best possible" way to solve this, just my own approach. Here, the service harness is called by the console app when in "console mode" and by the same application's "start service" logic when it is running as a service. By doing it this way, you can now call
ServiceHost.Instance.RunningAsAService (Boolean)
from anywhere in your code to check if the application is running as a service or simply as a console.
Here is the code:
public class ServiceHost
{
private static Logger log = LogManager.GetLogger(typeof(ServiceHost).Name);
private static ServiceHost mInstance = null;
private static object mSyncRoot = new object();
#region Singleton and Static Properties
public static ServiceHost Instance
{
get
{
if (mInstance == null)
{
lock (mSyncRoot)
{
if (mInstance == null)
{
mInstance = new ServiceHost();
}
}
}
return (mInstance);
}
}
public static Logger Log
{
get { return log; }
}
public static void Close()
{
lock (mSyncRoot)
{
if (mInstance.mEngine != null)
mInstance.mEngine.Dispose();
}
}
#endregion
private ReconciliationEngine mEngine;
private ServiceBase windowsServiceHost;
private UnhandledExceptionEventHandler threadExceptionHanlder = new UnhandledExceptionEventHandler(ThreadExceptionHandler);
public bool HostHealthy { get; private set; }
public bool RunningAsService {get; private set;}
private ServiceHost()
{
HostHealthy = false;
RunningAsService = false;
AppDomain.CurrentDomain.UnhandledException += threadExceptionHandler;
try
{
mEngine = new ReconciliationEngine();
HostHealthy = true;
}
catch (Exception ex)
{
log.FatalException("Could not initialize components.", ex);
}
}
public void StartService()
{
if (!HostHealthy)
throw new ApplicationException("Did not initialize components.");
try
{
mEngine.Start();
}
catch (Exception ex)
{
log.FatalException("Could not start service components.", ex);
HostHealthy = false;
}
}
public void StartService(ServiceBase serviceHost)
{
if (!HostHealthy)
throw new ApplicationException("Did not initialize components.");
if (serviceHost == null)
throw new ArgumentNullException("serviceHost");
windowsServiceHost = serviceHost;
RunningAsService = true;
try
{
mEngine.Start();
}
catch (Exception ex)
{
log.FatalException("Could not start service components.", ex);
HostHealthy = false;
}
}
public void RestartService()
{
if (!HostHealthy)
throw new ApplicationException("Did not initialize components.");
try
{
log.Info("Stopping service components...");
mEngine.Stop();
mEngine.Dispose();
log.Info("Starting service components...");
mEngine = new ReconciliationEngine();
mEngine.Start();
}
catch (Exception ex)
{
log.FatalException("Could not restart components.", ex);
HostHealthy = false;
}
}
public void StopService()
{
try
{
if (mEngine != null)
mEngine.Stop();
}
catch (Exception ex)
{
log.FatalException("Error stopping components.", ex);
HostHealthy = false;
}
finally
{
if (windowsServiceHost != null)
windowsServiceHost.Stop();
if (RunningAsService)
{
AppDomain.CurrentDomain.UnhandledException -= threadExceptionHanlder;
}
}
}
private void HandleExceptionBasedOnExecution(object ex)
{
if (RunningAsService)
{
windowsServiceHost.Stop();
}
else
{
throw (Exception)ex;
}
}
protected static void ThreadExceptionHandler(object sender, UnhandledExceptionEventArgs e)
{
log.FatalException("Unexpected error occurred. System is shutting down.", (Exception)e.ExceptionObject);
ServiceHost.Instance.HandleExceptionBasedOnExecution((Exception)e.ExceptionObject);
}
}
All you need to do here is replace that ominous looking ReconcilationEngine reference with whatever method is boostrapping your logic. Then in your application, use the ServiceHost.Instance.Start() and ServiceHost.Instance.Stop() methods whether you are running in console mode or as a service.
Maybe checking if the process parent is C:\Windows\system32\services.exe.
The only way I've found to achieve this, is to check if a console is attached to the process in the first place, by accessing any Console object property (e.g. Title) inside a try/catch block.
If the service is started by the SCM, there is no console, and accessing the property will throw a System.IO.IOError.
However, since this feels a bit too much like relying on an implementation-specific detail (what if the SCM on some platforms or someday decides to provide a console to the processes it starts?), I always use a command line switch (-console) in production apps...
Here is a translation of chksr's answer to .NET, and avoiding the bug that fails to recognize interactive services:
using System.Security.Principal;
var wi = WindowsIdentity.GetCurrent();
var wp = new WindowsPrincipal(wi);
var serviceSid = new SecurityIdentifier(WellKnownSidType.ServiceSid, null);
var localSystemSid = new SecurityIdentifier(WellKnownSidType.LocalSystemSid, null);
var interactiveSid = new SecurityIdentifier(WellKnownSidType.InteractiveSid, null);
// maybe check LocalServiceSid, and NetworkServiceSid also
bool isServiceRunningAsUser = wp.IsInRole(serviceSid);
bool isSystem = wp.IsInRole(localSystemSid);
bool isInteractive = wp.IsInRole(interactiveSid);
bool isAnyService = isServiceRunningAsUser || isSystem || !isInteractive;
This is a bit of a self-plug, but I've got a little app that will load up your service types in your app via reflection and execute them that way. I include the source code, so you could change it slightly to display standard output.
No code changes needed to use this solution. I have a Debugger.IsAttached type of solution as well that is generic enough to be used with any service. Link is in this article:
.NET Windows Service Runner
Well there's some very old code (about 20 years or so, not from me but found in the wild, wild web, and in C not C#) that should give you an idea how to do the job:
enum enEnvironmentType
{
ENVTYPE_UNKNOWN,
ENVTYPE_STANDARD,
ENVTYPE_SERVICE_WITH_INTERACTION,
ENVTYPE_SERVICE_WITHOUT_INTERACTION,
ENVTYPE_IIS_ASP,
};
enEnvironmentType GetEnvironmentType(void)
{
HANDLE hProcessToken = NULL;
DWORD groupLength = 300;
PTOKEN_GROUPS groupInfo = NULL;
SID_IDENTIFIER_AUTHORITY siaNt = SECURITY_NT_AUTHORITY;
PSID pInteractiveSid = NULL;
PSID pServiceSid = NULL;
DWORD dwRet = NO_ERROR;
DWORD ndx;
BOOL m_isInteractive = FALSE;
BOOL m_isService = FALSE;
// open the token
if (!::OpenProcessToken(::GetCurrentProcess(),TOKEN_QUERY,&hProcessToken))
{
dwRet = ::GetLastError();
goto closedown;
}
// allocate a buffer of default size
groupInfo = (PTOKEN_GROUPS)::LocalAlloc(0, groupLength);
if (groupInfo == NULL)
{
dwRet = ::GetLastError();
goto closedown;
}
// try to get the info
if (!::GetTokenInformation(hProcessToken, TokenGroups,
groupInfo, groupLength, &groupLength))
{
// if buffer was too small, allocate to proper size, otherwise error
if (::GetLastError() != ERROR_INSUFFICIENT_BUFFER)
{
dwRet = ::GetLastError();
goto closedown;
}
::LocalFree(groupInfo);
groupInfo = (PTOKEN_GROUPS)::LocalAlloc(0, groupLength);
if (groupInfo == NULL)
{
dwRet = ::GetLastError();
goto closedown;
}
if (!GetTokenInformation(hProcessToken, TokenGroups,
groupInfo, groupLength, &groupLength))
{
dwRet = ::GetLastError();
goto closedown;
}
}
//
// We now know the groups associated with this token. We want
// to look to see if the interactive group is active in the
// token, and if so, we know that this is an interactive process.
//
// We also look for the "service" SID, and if it's present,
// we know we're a service.
//
// The service SID will be present iff the service is running in a
// user account (and was invoked by the service controller).
//
// create comparison sids
if (!AllocateAndInitializeSid(&siaNt,
1,
SECURITY_INTERACTIVE_RID,
0, 0, 0, 0, 0, 0, 0,
&pInteractiveSid))
{
dwRet = ::GetLastError();
goto closedown;
}
if (!AllocateAndInitializeSid(&siaNt,
1,
SECURITY_SERVICE_RID,
0, 0, 0, 0, 0, 0, 0,
&pServiceSid))
{
dwRet = ::GetLastError();
goto closedown;
}
// try to match sids
for (ndx = 0; ndx < groupInfo->GroupCount ; ndx += 1)
{
SID_AND_ATTRIBUTES sanda = groupInfo->Groups[ndx];
PSID pSid = sanda.Sid;
//
// Check to see if the group we're looking at is one of
// the two groups we're interested in.
//
if (::EqualSid(pSid, pInteractiveSid))
{
//
// This process has the Interactive SID in its
// token. This means that the process is running as
// a console process
//
m_isInteractive = TRUE;
m_isService = FALSE;
break;
}
else if (::EqualSid(pSid, pServiceSid))
{
//
// This process has the Service SID in its
// token. This means that the process is running as
// a service running in a user account ( not local system ).
//
m_isService = TRUE;
m_isInteractive = FALSE;
break;
}
}
if ( !( m_isService || m_isInteractive ) )
{
//
// Neither Interactive or Service was present in the current
// users token, This implies that the process is running as
// a service, most likely running as LocalSystem.
//
m_isService = TRUE;
}
closedown:
if ( pServiceSid )
::FreeSid( pServiceSid );
if ( pInteractiveSid )
::FreeSid( pInteractiveSid );
if ( groupInfo )
::LocalFree( groupInfo );
if ( hProcessToken )
::CloseHandle( hProcessToken );
if (dwRet == NO_ERROR)
{
if (m_isService)
return(m_isInteractive ? ENVTYPE_SERVICE_WITH_INTERACTION : ENVTYPE_SERVICE_WITHOUT_INTERACTION);
return(ENVTYPE_STANDARD);
}
else
return(ENVTYPE_UNKNOWN);
}
Seems I am bit late to the party, but interesting difference when run as a service is that at start current folder points to system directory (C:\windows\system32 by default). Its hardly unlikely user app will start from the system folder in any real life situation.
So, I use following trick (c#):
protected static bool IsRunAsService()
{
string CurDir = Directory.GetCurrentDirectory();
if (CurDir.Equals(Environment.SystemDirectory, StringComparison.CurrentCultureIgnoreCase))
{
return true;
}
return (false);
}
For future extension, additional check make be done for System.Environment.UserInteractive == false (but I do not know how it correlates with 'Allow service to interact with desktop' service settings).
You may also check window session by System.Diagnostics.Process.GetCurrentProcess().SessionId == 0 (I do not know how it correlates with 'Allow service to interact with desktop' service settings as well).
If you write portable code (say, with .NetCore) you may also check Environment.OSVersion.Platform to ensure that you are on windows first.

Output message to Console window if command line parameters incorrect

Can anyone help me output a message to a console box when my .exe is called with the wrong parameters?
Yesterday, some very kind people helped me work out how to call my app without a UI
Here is the thread
command line to make winforms run without UI
So, I have told my app to respond to "/silent archive=true transcode=true" and runs without a UI. Great!
Is it possible to output a message to the command window if they get the command incorrect?
as in "Parameters must be specified like this: /silent archive=true transcode=true"
I have tried this but nothing displays in the dos window..
static void Main(string[] args)
{
if (args.Length > 0)
{
if (args[0] == "/silent")
{
bool archive = false;
bool transcode = false;
try
{
if (args[1] == "transcode=true") { transcode = true; };
if (args[2] == "archive=true") { archive = true; };
Citrix_API_Tool.Engine.DownloadFiles(transcode, archive);
}
catch
{
Console.Write ("Hello");
Console.ReadLine();
return;
}
}
}
else
internal sealed class Program
{
[DllImport("kernel32.dll")]
private static extern bool AttachConsole(int dwProcessId);
private const int ATTACH_PARENT_PROCESS = -1;
[STAThread]
private static void Main(string[] args)
{
if(false)//This would be the run-silent check.
{
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
Application.Run(new MainForm());
}
try
{
throw new Exception("Always throw, as this tests exception handling.");
}
catch(Exception e)
{
if(AttachConsole(ATTACH_PARENT_PROCESS))
{
//Note, we write to Console.Error, not Console.Out
//Partly because that's what error is for.
//Mainly so if our output were being redirected into a file,
//We'd write to console instead of there.
//Likewise, if error is redirected to some logger or something
//That's where we should write.
Console.Error.WriteLine();//Write blank line because of issue described below
Console.Error.WriteLine(e.Message);
Console.Error.WriteLine();//Write blank line because of issue described below
}
else
{
//Failed to attach - not opened from console, or console closed.
//do something else.
}
}
}
}
A problem is that the console would have already returned to taking input from the user. Hence you really want to try to have your exception as fast as you can if you're going to have it, so a fast validation check rather than an exception that might happen down the line, is preferable.

Windows Service - Crashes At Startup

I have built a windows Service to monitor a few settings on our servers, I have developed quite a few WinForm and WPF apps but I am an absolute newbie when it comes to Windows Services, which is why I resorted to msdn and followed the tutorial on how to create a simple service. Now I can install the service just fine and make it run, but only if I cut some bits and pieces out of the microsoft tutorial.. but I am curious why, when I follow the tutorial, my service gets an unexpected error at startup.
After some testing it seems that the service seems to crash in the onstart method at SetServiceStatus()
public partial class MyService: ServiceBase
{
private static ManualResetEvent pause = new ManualResetEvent(false);
[DllImport("ADVAPI32.DLL", EntryPoint = "SetServiceStatus")]
public static extern bool SetServiceStatus(IntPtr hServiceStatus, SERVICE_STATUS lpServiceStatus);
private SERVICE_STATUS myServiceStatus;
private Thread workerThread = null;
public MyService()
{
InitializeComponent();
CanPauseAndContinue = true;
CanHandleSessionChangeEvent = true;
ServiceName = "MyService";
}
static void Main()
{
// Load the service into memory.
System.ServiceProcess.ServiceBase.Run(MyService());
}
protected override void OnStart(string[] args)
{
IntPtr handle = this.ServiceHandle;
myServiceStatus.currentState = (int)State.SERVICE_START_PENDING;
**SetServiceStatus(handle, myServiceStatus);**
// Start a separate thread that does the actual work.
if ((workerThread == null) || ((workerThread.ThreadState & (System.Threading.ThreadState.Unstarted | System.Threading.ThreadState.Stopped)) != 0))
{
workerThread = new Thread(new ThreadStart(ServiceWorkerMethod));
workerThread.Start();
}
myServiceStatus.currentState = (int)State.SERVICE_RUNNING;
SetServiceStatus(handle, myServiceStatus);
}
}
Now my service seems to run just fine when I comment out the SetServiceStatus() lines. Why does this fail? Is this a rights-issue or am I completely missing the point here?
In general, you shouldn't have to call SetServiceStatus when implementing a managed service using the framework.
That being said, if you do call it, you need to fully initialize the SERVICE_STATUS before using it. You're currently only setting the state, but none of the other variables.
This is suggested in the best practices for SetServiceStatus: "Initialize all fields in the SERVICE_STATUS structure, ensuring that there are valid check-point and wait hint values for pending states. Use reasonable wait hints."

How Might I Convert This C# Code In To Batch File Code?

I have read that Win32 will not allow remote invocation of a process that is interactive and I suspect a Console Application is considered to be interactive by Windows and so instead, if I could convert the following code in to a batch file then I am hoping I can remotely run the batch file on the server computer from a client. Feel free to correct this logic if I'm wrong.
The code is:
namespace PRIMEWebFlyControl
{
class Program
{
// name of the process we will retrieve a handle to
private const string PROCESS_NAME = "PRIMEPipeLine";
private static Process ProgramHandle;
private static string command;
static void Main(string[] args)
{
//Console.WriteLine("This program has been launched remotely!");
TextReader tr = new StreamReader("C:\\inetpub\\wwwroot\\PRIMEWeb\\Executables\\FlyCommand.txt");
command = tr.ReadLine();
tr.Close();
ExecuteCommand();
}
[DllImport("user32.dll")]
static extern bool SetForegroundWindow(IntPtr handle);
private static void ExecuteCommand() {
if (AssignProcessHandle()) {
IntPtr p = ProgramHandle.MainWindowHandle;
SetForegroundWindow(p);
SendKeys.SendWait(command + "~"); // "~" is equivalent to pressing Enter
}
}
private static bool AssignProcessHandle()
{
// ask the system for all processes that match the name we are looking for
Process[] matchingProcesses = Process.GetProcessesByName(PROCESS_NAME);
// if none are returned then we haven't found the program so return false;
if (matchingProcesses.Length == 0) return false;
// else, set our reference to the running program
ProgramHandle = matchingProcesses[0];
// return true to indicate we have assigned the ref sucessfully
return true;
}
}
}
As you will notice the code contains method calls of Windows library methods like SetForegroundWindow() and as I am unfamiliar with batch files, I wondered how the same thing might be achieved.
Many thanks
If I understand well, you are looking for a command line that will execute a bunch of commands that exist inside a text file named (C:\inetpub\wwwroot\PRIMEWeb\Executables\FlyCommand.txt)
Here is what you need to do:
cmd < C:\inetpub\wwwroot\PRIMEWeb\Executables\FlyCommand.txt
In case the path contains spaces, use the following command:
cmd < "C:\inetpub\wwwroot\PRIMEWeb\Executables\FlyCommand.txt"

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