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Process.WaitForExit hangs even without using RedirectStandardError/RedirectStandardOutput

We have a service which starts a process and waits for process to exit when service is stopped/ user of service calls stop (to stop/kill process started by service).
Sporadically, process.waitForExit(TimeSpan) hangs.
Please note that process started by Service is native process (C++/CLI) process and service is in C#.
Following is the code snippet we are using
public class ApplicationProcessControl : IProcessControl
{
private Process _proc;
private const int ProcessIdleTimeout = 5000;
public bool Start(string arguments)
{
if (IsAlive)
{
Log.TraceInfo("Application process already running. Killing it now...");
_proc.Kill();
}
var eProcStarted = new Mutex(false, "Mutex111");
_proc = new Process { EnableRaisingEvents = true, StartInfo = new ProcessStartInfo(_exePath, arguments) { RedirectStandardOutput = false,RedirectStandardError = false};
_proc.Exited += OnProcessExited;
_proc.Start();
bool started;
if(_proc == null)
{
Log.TraceInfo("Unable to start application process");
started = false;
}
else
{
started = eProcStarted.WaitOne(ProcessIdleTimeout);
if(started)
{
Log.TraceInfo($"Application process with id {_proc.Id} started successfully");
}
}
eProcStarted.Dispose();
return started;
}
public void Kill()
{
_proc.Kill();
}
public bool WaitForProcessToExit(TimeSpan timeout)
{
return _proc.WaitForExit((int) timeout.TotalMilliseconds);
}
public event Action ProcessExited;
private void OnProcessExited(object sender, EventArgs e)
{
var proc = sender as Process;
if(proc != null)
{
proc.Exited -= OnProcessExited;
if(proc.ExitCode == 0)
{
Log.TraceInfo("Application process exited gracefully");
}
else
{
Log.DeveloperWarning("Application process exited unexpectedly with code {0}", proc.ExitCode);
OnProcessExited();
}
}
}
private void OnProcessExited()
{
Action handler = ProcessExited;
handler?.Invoke();
}
}
public interface IProcessControl
{
bool IsAlive { get; }
bool Start(string arguments);
bool WaitForProcessToExit(TimeSpan timeout);
void Kill();
event Action ProcessExited;
}
public class ApplicationClientService: DisposableObject, IComponentService, ITaskControl, IUIControl,
IDataProvider<AngleFlavors>, IApplicationCloseNotifier
{
//...
private readonly IProcessControl _procCtrl;
public ApplicationClientService(IObjectProvider objPro)
{
//...
_procCtrl.ProcessExited += OnApplicationProcessExited;
}
public void Stop()
{
//...
CleanUpAppProcess();
//...
}
private void CleanUpAppProcess()
{
//...
if(!_procCtrl.WaitForProcessToExit(TimeSpan.FromSeconds(5)))
{
_procCtrl.Kill();
}
}
private void OnApplicationProcessExited()
{
if(!_isAppRunning)
{
return;
}
_isAppRunning = false;
_autoLaunchRequested = false;
RaiseApplicationClosed();
Log.DeveloperWarning("Application process closed unexpectedly");
Log.UserMessageApplicationClosedUnexpectedly();
...
}
protected virtual void RaiseApplicationClosed()
{
//AuditApplicationStop();
//ApplicationClosed?.Invoke();
}
}

Don't know if this can answer your question (I have myself more questions than answers on this), but this code:
private void CleanUpAppProcess()
{
//...
if(!_procCtrl.WaitForProcessToExit(TimeSpan.FromSeconds(5)))
{
_procCtrl.Kill();
}
}
calls WaitForExit before the Kill command. Are you expecting the process to terminate by itself / to be terminated by a user in between 5 seconds? As Bennie Zhitomirsky pointed out in his comment, the mutex is not owned when it should be (if I understood correctly what you want to achieve, if not, sorry). What about the implementation of IsAlive?
Anyway, I put down some lines for the ApplicationProcessControl class. I just tested it a bit with some native process and seems to work (but still, I'm not sure this is what you're trying to achive):
public class ApplicationProcessControl : IProcessControl
{
/// <summary>
/// Process instance variable.
/// </summary>
private Process _proc;
/// <summary>
/// The thread will try to acquire the mutex for a maximum of _mutexAcquireTimeout ms.
/// </summary>
private const int _mutexAcquireTimeout = 5000;
/// <summary>
/// Global static named mutex, seen by all threads.
/// </summary>
private static Mutex SpawnProcessMutex = new Mutex(false, "Mutex111");
/// <summary>
/// The state of the process.
/// </summary>
public bool IsAlive
{
get { return !(_proc is null) && !_proc.HasExited; }
}
/// <summary>
/// Spawns a new process.
/// </summary>
public bool Start(string arguments)
{
// Try to acquire the mutex for _mutexAcquireTimeout ms.
if (!SpawnProcessMutex.WaitOne(_mutexAcquireTimeout) || IsAlive)
{
// Mutex is still owned (another thread got it and is trying to run the process)
// OR the process is already running.
// DO NOT start a new process.
return false;
}
try
{
// Mutex is acquired by this thread.
// Create a new instance of the Process class.
_proc = new Process
{
EnableRaisingEvents = true,
StartInfo = new ProcessStartInfo("the_process_to_be_run", arguments)
{
RedirectStandardOutput = false,
RedirectStandardError = false
}
};
// Subscription to the ProcessExited event.
_proc.Exited += OnProcessExited;
// Run the process.
var haveAnHandle = _proc.Start();
// *******
// TODO: The process started but we may not have an handle to it. What to do?
// *******
//Log.TraceInfo($"Application process with id {_proc.Id} started successfully");
return true;
}
catch (Exception) // TODO: [Catch the specific exceptions here]
{
// The process failed to start, still we have an instance of Process with no use.
if (!(_proc is null))
{
_proc.Dispose();
_proc = null;
}
//Log.TraceInfo("Unable to start application process");
return false;
}
finally
{
// Release the mutex, another thread may be waiting to acquire it.
SpawnProcessMutex.ReleaseMutex();
}
}
/// <summary>
/// Kills the process started by the Start method.
/// </summary>
public void Kill()
{
if (IsAlive) _proc.Kill();
}
/// <summary>
/// Can't see a real reason to block the thread waiting synchronously for the process to
/// exit, we are already subscribed to the Exited event.
/// Kept here to avoid breaking the interface contract.
/// </summary>
public bool WaitForProcessToExit(TimeSpan timeout)
{
return _proc.WaitForExit((int)timeout.TotalMilliseconds);
}
/// <summary>
/// Client class consumable event to know the the process actually terminated.
/// </summary>
public event Action ProcessExited;
/// <summary>
/// Process Exited event handler.
/// </summary>
private void OnProcessExited(object sender, EventArgs e)
{
// Get a reference to the actual Process object.
var proc = sender as Process;
if (proc is null) return;
proc.Exited -= OnProcessExited;
if (proc.ExitCode == 0)
{
// Log.TraceInfo("Application process exited gracefully");
}
else
{
// Log.DeveloperWarning("Application process exited unexpectedly with code {0}", proc.ExitCode);
ProcessExited?.Invoke();
}
}
}

Is System.Diagnostics.EventLog leaking memory?

When I run the following code :
static void Main(string[] args)
{
if (!System.Diagnostics.EventLog.SourceExists("eventSource"))
{
System.Diagnostics.EventLog.CreateEventSource("eventSource", "");
}
System.Diagnostics.EventLog eventLog = new System.Diagnostics.EventLog();
eventLog.Source = "eventSource";
eventLog.Log = "";
for (int i = 0; i < 10000; i++)
{
Thread.Sleep(100);
eventLog.WriteEntry("test", EventLogEntryType.Information);
//I also tried the static method, the program still leaks
//System.Diagnostics.EventLog.WriteEntry("eventSource", "test", EventLogEntryType.Information);
}
Console.ReadKey();
}
The memory usage starts around 1MB, but rise up very quickly and doesn't stop. Why ?

The code I'm using to install windows service with a designated event log:
[RunInstaller(true)]
public partial class SampleServiceInstaller : System.Configuration.Install.Installer
{
private string SampleServiceName = string.Empty;
private string SampleLogName = string.Empty;
public SampleServiceInstaller()
{
this.SampleServiceName = "SampleService";
this.SampleLogName = this.SampleServiceName + "Log";
ServiceProcessInstaller serviceProcessInstaller = new ServiceProcessInstaller();
serviceProcessInstaller.Password = null;
serviceProcessInstaller.Username = null;
serviceProcessInstaller.Account = ServiceAccount.LocalSystem;
ServiceInstaller serviceInstaller = new ServiceInstaller();
//This must be identical to the WindowsService.ServiceBase name
// set in the constructor of WindowsService.cs
serviceInstaller.ServiceName = this.SampleServiceName;
serviceInstaller.DisplayName = this.SampleServiceName;
serviceInstaller.StartType = ServiceStartMode.Automatic;
serviceInstaller.Description = "Sample Windows Service";
// kill the default event log installer
serviceInstaller.Installers.Clear();
// Create Event Source and Event Log    
// This recreates the log every time the service is reinstaled (old messages are lost)
if (EventLog.SourceExists(this.SampleServiceName)) EventLog.DeleteEventSource(this.SampleServiceName);
System.Diagnostics.EventLogInstaller logInstaller = new System.Diagnostics.EventLogInstaller();
logInstaller.Source = this.SampleServiceName; // use same as ServiceName
logInstaller.Log = this.SampleLogName; //can't be the same as service name
// Add all installers
this.Installers.AddRange(new Installer[] {
   serviceProcessInstaller, serviceInstaller, logInstaller
});
}
public override void Install(System.Collections.IDictionary savedState)
{
base.Install(savedState);
}
protected override void OnBeforeUninstall(System.Collections.IDictionary savedState)
{
base.OnBeforeUninstall(savedState);
}
service code:
public partial class SampleService : ServiceBase
{
/// <summary>
/// Designer variable.
/// </summary>
private System.ComponentModel.IContainer components = null;
/// <summary>
/// Event log for the service
/// </summary>
EventLog serviceLog;
/// <summary>
/// Public Constructor for WindowsService.
/// - Initialization code here.
/// </summary>
public SampleService()
{
InitializeComponent();
}
/// <summary>
/// The Main Thread: list of services to run.
/// </summary>
static void Main()
{
ServiceBase[] ServicesToRun;
ServicesToRun = new ServiceBase[] { new SampleService() };
ServiceBase.Run(ServicesToRun);
}
/// <summary>
/// Startup code
/// </summary>
/// <param name="args"></param>
protected override void OnStart(string[] args)
{
base.OnStart(args);
//
// run your own start code here
//
serviceLog.WriteEntry("My service started", EventLogEntryType.Information, 0);
}
/// <summary>
/// Stop code
/// </summary>
protected override void OnStop()
{
//
// run your own stop code here
//
serviceLog.WriteEntry("My service stopped", EventLogEntryType.Information, 0);
base.OnStop();
}
/// <summary>
/// Cleanup code
/// </summary>
/// <param name="disposing"></param>
protected override void Dispose(bool disposing)
{
//
// do disposing here
//
if (disposing && (components != null))
{
components.Dispose();
}
base.Dispose(disposing);
}
/// <summary>
/// Pause code
/// </summary>
protected override void OnPause()
{
base.OnPause();
//
// code to run if service pauses
//
}
/// <summary>
/// Continue code
/// </summary>
protected override void OnContinue()
{
base.OnContinue();
//
// code tu run when service continues after being paused
//
}
/// <summary>
/// Called when the System is shutting down
/// - when special handling
/// of code that deals with a system shutdown, such
/// as saving special data before shutdown is needed.
/// </summary>
protected override void OnShutdown()
{
//
// code tu run when system is shut down
//
base.OnShutdown();
}
/// <summary>
/// If sending a command to the service is needed
/// without the need for Remoting or Sockets,
/// this method is used to do custom methods.
/// int command = 128; //Some Arbitrary number between 128 & 256
/// ServiceController sc = new ServiceController("NameOfService");
/// sc.ExecuteCommand(command);
/// </summary>
/// <param name="command">Arbitrary Integer between 128 & 256</param>
protected override void OnCustomCommand(int command)
{
base.OnCustomCommand(command);
//
// handle custom code here
//
}
/// <summary>
/// Useful for detecting power status changes,
/// such as going into Suspend mode or Low Battery for laptops.
/// </summary>
/// <param name="powerStatus">The Power Broadcast Status
/// (BatteryLow, Suspend, etc.)</param>
protected override bool OnPowerEvent(PowerBroadcastStatus powerStatus)
{
//
// handle power events here
//
return base.OnPowerEvent(powerStatus);
}
/// <summary>
/// To handle a change event
/// from a Terminal Server session.
/// Useful if determining
/// when a user logs in remotely or logs off,
/// or when someone logs into the console is needed.
/// </summary>
/// <param name="changeDescription">The Session Change
/// Event that occured.</param>
protected override void OnSessionChange(SessionChangeDescription changeDescription)
{
//
// handle session change here
//
base.OnSessionChange(changeDescription);
}
private void InitializeComponent()
{
components = new System.ComponentModel.Container();
// first 8 letters should be unique
this.ServiceName = "SampleService";
// if you want to log service event to log registered while installing the service
string newLogName = this.ServiceName + "Log";
string newSourceName = this.ServiceName;
if (!EventLog.SourceExists(newSourceName))
{
EventLog.CreateEventSource(newSourceName, newLogName);
}
serviceLog = new EventLog();
serviceLog.Source = newSourceName;
serviceLog.Log = newLogName;
// Causes log to be disposed when the service is disposed
components.Add(serviceLog);
// Flags set whether or not to handle that specific type of event.
this.CanHandlePowerEvent = true;
this.CanHandleSessionChangeEvent = true;
this.CanPauseAndContinue = true;
this.CanShutdown = true;
this.CanStop = true;
}
}

C# only one instance of program - open few files

I did everything from Example: What is the correct way to create a single-instance application? by Matt Davis.
However, I have an application to open files. I have this code:
static Mutex mutex = new Mutex(true, "{MyApplicationTest}");
[STAThread]
static void Main(string[] args)
{
if (mutex.WaitOne(TimeSpan.Zero, true))
{
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
Application.Run(args.Length == 0 ? new Form1(string.Empty) : new Form1(args[0]));
mutex.ReleaseMutex();
}
else
{
NativeMethods.PostMessage(
(IntPtr)NativeMethods.HWND_BROADCAST,
NativeMethods.WM_SHOWME,
IntPtr.Zero,
IntPtr.Zero);
}
How does open the next file in the case when the program is already running. The first file automatically opens. In contrast, the next click will only appearance of the application window on top of the screen.

Problem solved, thanks xxbbcc http://www.hanselman.com/blog/TheWeeklySourceCode31SingleInstanceWinFormsAndMicrosoftVisualBasicdll.aspx
using System;
using System.Windows.Forms;
using Microsoft.VisualBasic.ApplicationServices;
namespace SuperSingleInstance
{
static class Program
{
[STAThread]
static void Main()
{
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
string[] args = Environment.GetCommandLineArgs();
SingleInstanceController controller = new SingleInstanceController();
controller.Run(args);
}
}
public class SingleInstanceController : WindowsFormsApplicationBase
{
public SingleInstanceController()
{
IsSingleInstance = true;
StartupNextInstance += this_StartupNextInstance;
}
void this_StartupNextInstance(object sender, StartupNextInstanceEventArgs e)
{
Form1 form = MainForm as Form1; //My derived form type
form.LoadFile(e.CommandLine[1]);
}
protected override void OnCreateMainForm()
{
MainForm = new Form1();
}
}
}

Here is a Utility Class That I wrote a while back for a similar purpose.
(I guess the name GlobalMutexHelper is kind of redundant in this case, the name kind of stuck :)..anyways)
Since it implements IDisposable you can use it like so
using(var Mutexhelper=new GlobalMutexHelper("reasonably unique Name"))
{
//Code goes here
}
Its not necessary that this be implemented as an IDisposable but in my case I need it to be handy
as sometimes the "Single Instanceness" had to be dependent on other factors.
internal class GlobalMutexHelper : IDisposable
{
#region Constants and Fields
/// <summary>
/// The access rule.
/// </summary>
private readonly MutexAccessRule accessRule =
new MutexAccessRule(
new SecurityIdentifier(WellKnownSidType.WorldSid, null),
MutexRights.FullControl,
AccessControlType.Allow);
/// <summary>
/// The obj.
/// </summary>
private readonly Mutex obj;
/// <summary>
/// The sec settings.
/// </summary>
private readonly MutexSecurity secSettings = new MutexSecurity();
#endregion
#region Constructors and Destructors
/// <summary>
/// Initializes a new instance of the <see cref="GlobalMutexHelper"/> class.
/// </summary>
/// <param name="mutexname">
/// The mutexname.
/// </param>
/// <exception cref="TimeoutException">
/// </exception>
/// <exception cref="Exception">
/// </exception>
public GlobalMutexHelper(string mutexname)
{
if (mutexname.Trim() != string.Empty)
{
this.secSettings.AddAccessRule(this.accessRule);
bool isNew;
this.obj = new Mutex(true, "Global\\SomeUniqueName_" + mutexname, out isNew);
this.obj.SetAccessControl(this.secSettings);
if (!isNew)
{
if (this.obj.WaitOne())
{
Console.WriteLine("Signalled");
}
else
{
throw new TimeoutException("Timedout while waiting for Mutex");
}
}
}
else
{
throw new Exception("The mutex name cannot be empty");
}
}
#endregion
#region Public Methods and Operators
/// <summary>
/// The dispose.
/// </summary>
public void Dispose()
{
this.obj.ReleaseMutex();
this.obj.Dispose();
}
#endregion
}

Application.Restart() + Single Instance conflict in windows application

Hi Friends,
I have a windows application where i controls single instance.
When this application updates using clickonce, application will restart after applying updates.
The application restarts but fails to continue as, IsFirstInstance = false condition.
But Application.Restart() documentation says it shutdowns running app and creates new instance.
Single instance class is given below:
using System;
using System.Diagnostics;
using System.Runtime.Remoting;
using System.Runtime.Remoting.Channels;
using System.Runtime.Remoting.Channels.Ipc;
using System.Threading;
using agent_common_plugin_sdk;
/// <summary>
/// Application Instance Manager
/// </summary>
public static class ApplicationInstanceManager
{
/// <summary>
/// Creates the single instance.
/// </summary>
/// <param name="name">The name.</param>
/// <param name="callback">The callback.</param>
/// <returns></returns>
public static bool CreateSingleInstance(string name, EventHandler<InstanceCallbackEventArgs> callback)
{
EventWaitHandle eventWaitHandle = null;
string eventName = string.Format("{0}-{1}", Environment.MachineName, name);
InstanceProxy.IsFirstInstance = false;
InstanceProxy.CommandLineArgs = Environment.GetCommandLineArgs();
try
{
// Try opening existing wait handle
eventWaitHandle = EventWaitHandle.OpenExisting(eventName);
}
catch(Exception ex)
{
// Got exception = handle wasn't created yet
InstanceProxy.IsFirstInstance = true;
}
if (InstanceProxy.IsFirstInstance)
{
// init handle
eventWaitHandle = new EventWaitHandle(false, EventResetMode.AutoReset, eventName);
// register wait handle for this instance (process)
ThreadPool.RegisterWaitForSingleObject(eventWaitHandle, WaitOrTimerCallback, callback, Timeout.Infinite, false);
eventWaitHandle.Close();
// register shared type (used to pass data between processes)
RegisterRemoteType(name);
}
else
{
// pass console arguments to shared object
UpdateRemoteObject(name);
// invoke (signal) wait handle on other process
if (eventWaitHandle != null) eventWaitHandle.Set();
// kill current process
Environment.Exit(0);
}
return InstanceProxy.IsFirstInstance;
}
/// <summary>
/// Updates the remote object.
/// </summary>
/// <param name="uri">The remote URI.</param>
private static void UpdateRemoteObject(string uri)
{
// register net-pipe channel
IpcClientChannel clientChannel = new IpcClientChannel();
ChannelServices.RegisterChannel(clientChannel, true);
// get shared object from other process
InstanceProxy proxy =
Activator.GetObject(typeof(InstanceProxy),
string.Format("ipc://{0}{1}/{1}", Environment.MachineName, uri)) as InstanceProxy;
// pass current command line args to proxy
if (proxy != null)
proxy.SetCommandLineArgs(InstanceProxy.IsFirstInstance, InstanceProxy.CommandLineArgs);
// close current client channel
ChannelServices.UnregisterChannel(clientChannel);
}
/// <summary>
/// Registers the remote type.
/// </summary>
/// <param name="uri">The URI.</param>
private static void RegisterRemoteType(string uri)
{
// register remote channel (net-pipes)
IpcServerChannel serverChannel = new IpcServerChannel(Environment.MachineName + uri);
ChannelServices.RegisterChannel(serverChannel, true);
// register shared type
RemotingConfiguration.RegisterWellKnownServiceType(
typeof(InstanceProxy), uri, WellKnownObjectMode.Singleton);
// close channel, on process exit
Process process = Process.GetCurrentProcess();
process.Exited += delegate { ChannelServices.UnregisterChannel(serverChannel); };
}
/// <summary>
/// Wait Or Timer Callback Handler
/// </summary>
/// <param name="state">The state.</param>
/// <param name="timedOut">if set to <c>true</c> [timed out].</param>
private static void WaitOrTimerCallback(object state, bool timedOut)
{
// cast to event handler
EventHandler<InstanceCallbackEventArgs> callback = state as EventHandler<InstanceCallbackEventArgs>;
if (callback == null) return;
// invoke event handler on other process
callback(state,
new InstanceCallbackEventArgs(InstanceProxy.IsFirstInstance,
InstanceProxy.CommandLineArgs));
}
}
}
here:
try
{
// Try opening existing wait handle
eventWaitHandle = EventWaitHandle.OpenExisting(eventName);
}
catch(Exception ex)
{
// Got exception = handle wasn't created yet
InstanceProxy.IsFirstInstance = true;
}
no exception is being thrown. Hence as you can see in the code, it will exit from Environment.Exit(0).

WatiN unreliable for repeated downloads?

WatiN seems to not handle repeated download dialogs consistently:
foreach (string file in lstFiles)
{
// continue if no download link
if (!ie.Element([search criteria]).Exists) continue;
var btnDownload = ie.Element([search criteria]);
string fullFilename = workingDir + "\\" + file;
FileDownloadHandler download = new FileDownloadHandler(fullFilename);
using (new UseDialogOnce(ie.DialogWatcher, download))
{
btnDownload.ClickNoWait();
download.WaitUntilFileDownloadDialogIsHandled(30);
download.WaitUntilDownloadCompleted(150);
ie.RemoveDialogHandler(download);
}
}
Basically, I loop through a list of filenames that I expect to be available and click the download button. This usually works, but after so many downloads (it varies, sometimes everything that's available downloads, sometimes nothing) it will hang while waiting to handle the dialog. The button's identified correctly, the download dialog appears, it just isn't detected and handled. It isn't site-specific as similar methods on other sites are also met with variable success. Anyone encounter this before and know of a resolution?
edit: Repeated downloads do not work whatsoever in Server 2008. In Win7, this happens randomly after one or more successful repeated downloads.

The problem appears because IE File Download Dialog consist of 2 windows. WatiN DialogWatcher gets all the system windows and tries to handle them in foreach loop. After handling first correct dialog window DialogWatcher gets the next window wich has the same properties and is a valid Download Dialog. DialogWatcher starts waiting until this window is visible but it closes immediately after previos window is handled.
My solution is to return from foreach loop after any dialog is handled:
#region WatiN Copyright (C) 2006-2011 Jeroen van Menen
//Copyright 2006-2011 Jeroen van Menen
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#endregion Copyright
using System;
using System.Collections.Generic;
using System.Threading;
using WatiN.Core.Exceptions;
using WatiN.Core.Interfaces;
using WatiN.Core.Logging;
using WatiN.Core.Native.InternetExplorer;
using WatiN.Core.Native.Windows;
using WatiN.Core.UtilityClasses;
namespace WatiN.Core.DialogHandlers
{
/// <summary>
/// This class handles alert/popup dialogs. Every second it checks if a dialog
/// is shown. If so, it stores it's message in the alertQueue and closses the dialog
/// by clicking the close button in the title bar.
/// </summary>
public class DialogWatcher : IDisposable
{
private static IList<DialogWatcher> dialogWatchers = new List<DialogWatcher>();
private bool _keepRunning = true;
private readonly IList<IDialogHandler> _handlers;
private readonly Thread _watcherThread;
private bool _closeUnhandledDialogs = Settings.AutoCloseDialogs;
public Window MainWindow { get; private set; }
/// <summary>
/// Gets the dialog watcher for the specified (main) internet explorer window.
/// It creates new instance if no dialog watcher for the specified window exists.
/// </summary>
/// <param name="mainWindowHwnd">The (main) internet explorer window.</param>
/// <returns></returns>
public static DialogWatcher GetDialogWatcher(IntPtr mainWindowHwnd)
{
var window = new Window(mainWindowHwnd);
Logger.LogDebug("GetDialogWatcher mainhwnd: " + window.Hwnd + ", " + window.Title);
var toplevelWindow = window.ToplevelWindow;
Logger.LogDebug("GetDialogWatcher mainhwnd: " + toplevelWindow.Hwnd + ", " + toplevelWindow.Title);
CleanupDialogWatcherCache();
var dialogWatcher = GetDialogWatcherFromCache(toplevelWindow);
// If no dialogwatcher exists for the ieprocessid then
// create a new one, store it and return it.
if (dialogWatcher == null)
{
dialogWatcher = new DialogWatcher(toplevelWindow);
dialogWatchers.Add(dialogWatcher);
}
return dialogWatcher;
}
public static DialogWatcher GetDialogWatcherFromCache(Window mainWindow)
{
// Loop through already created dialogwatchers and
// return a dialogWatcher if one exists for the given processid
foreach (var dialogWatcher in dialogWatchers)
{
if (dialogWatcher.MainWindow.Equals(mainWindow))
{
return dialogWatcher;
}
}
return null;
}
public static void CleanupDialogWatcherCache()
{
var cleanedupDialogWatcherCache = new List<DialogWatcher>();
foreach (var dialogWatcher in dialogWatchers)
{
if (!dialogWatcher.IsRunning)
{
dialogWatcher.Dispose();
}
else
{
cleanedupDialogWatcherCache.Add(dialogWatcher);
}
}
dialogWatchers = cleanedupDialogWatcherCache;
}
/// <summary>
/// Initializes a new instance of the <see cref="DialogWatcher"/> class.
/// You are encouraged to use the Factory method <see cref="DialogWatcher.GetDialogWatcherFromCache"/>
/// instead.
/// </summary>
/// <param name="mainWindow">The main window handle of internet explorer.</param>
public DialogWatcher(Window mainWindow)
{
MainWindow = mainWindow;
_handlers = new List<IDialogHandler>();
// Create thread to watch windows
_watcherThread = new Thread(Start);
// Start the thread.
_watcherThread.Start();
}
/// <summary>
/// Increases the reference count of this DialogWatcher instance with 1.
/// </summary>
public void IncreaseReferenceCount()
{
ReferenceCount++;
}
/// <summary>
/// Decreases the reference count of this DialogWatcher instance with 1.
/// When reference count becomes zero, the Dispose method will be
/// automatically called. This method will throw an <see cref="ReferenceCountException"/>
/// if the reference count is zero.
/// </summary>
public void DecreaseReferenceCount()
{
if (ReferenceCount > 0)
{
ReferenceCount--;
}
else
{
throw new ReferenceCountException();
}
if (ReferenceCount == 0)
{
Dispose();
}
}
/// <summary>
/// Adds the specified handler.
/// </summary>
/// <param name="handler">The handler.</param>
public void Add(IDialogHandler handler)
{
lock (this)
{
_handlers.Add(handler);
}
}
/// <summary>
/// Removes the specified handler.
/// </summary>
/// <param name="handler">The handler.</param>
public void Remove(IDialogHandler handler)
{
lock (this)
{
_handlers.Remove(handler);
}
}
/// <summary>
/// Removes all instances that match <paramref name="handler"/>.
/// This method determines equality by calling Object.Equals.
/// </summary>
/// <param name="handler">The object implementing IDialogHandler.</param>
/// <example>
/// If you want to use RemoveAll with your custom dialog handler to
/// remove all instances of your dialog handler from a DialogWatcher instance,
/// you should override the Equals method in your custom dialog handler class
/// like this:
/// <code>
/// public override bool Equals(object obj)
/// {
/// if (obj == null) return false;
///
/// return (obj is YourDialogHandlerClassNameGoesHere);
/// }
/// </code>
/// You could also inherit from <see cref="BaseDialogHandler"/> instead of implementing
/// <see cref="IDialogHandler"/> in your custom dialog handler. <see cref="BaseDialogHandler"/> provides
/// overrides for Equals and GetHashCode that work with RemoveAll.
/// </example>
public void RemoveAll(IDialogHandler handler)
{
while (Contains(handler))
{
Remove(handler);
}
}
/// <summary>
/// Removes all registered dialog handlers.
/// </summary>
public void Clear()
{
lock (this)
{
_handlers.Clear();
}
}
/// <summary>
/// Determines whether this <see cref="DialogWatcher"/> contains the specified dialog handler.
/// </summary>
/// <param name="handler">The dialog handler.</param>
/// <returns>
/// <c>true</c> if [contains] [the specified handler]; otherwise, <c>false</c>.
/// </returns>
public bool Contains(IDialogHandler handler)
{
lock (this)
{
return _handlers.Contains(handler);
}
}
/// <summary>
/// Gets the count of registered dialog handlers.
/// </summary>
/// <value>The count.</value>
public int Count
{
get
{
lock (this)
{
return _handlers.Count;
}
}
}
/// <summary>
/// Gets or sets a value indicating whether unhandled dialogs should be closed automaticaly.
/// The initial value is set to the value of <cref name="Settings.AutoCloseDialogs" />.
/// </summary>
/// <value>
/// <c>true</c> if unhandled dialogs should be closed automaticaly; otherwise, <c>false</c>.
/// </value>
public bool CloseUnhandledDialogs
{
get
{
lock (this)
{
return _closeUnhandledDialogs;
}
}
set
{
lock (this)
{
_closeUnhandledDialogs = value;
}
}
}
/// <summary>
/// Gets the (main) internet explorer window handle this dialog watcher watches.
/// </summary>
/// <value>The process id.</value>
public IntPtr MainWindowHwnd
{
get { return MainWindow.Hwnd; }
}
/// <summary>
/// Called by the constructor to start watching popups
/// on a separate thread.
/// </summary>
private void Start()
{
while (_keepRunning)
{
if (MainWindow.Exists())
{
var winEnumerator = new WindowsEnumerator();
var windows = winEnumerator.GetWindows(win => true);
foreach (var window in windows)
{
if (!_keepRunning) return;
if(HandleWindow(window))
break;
}
// Keep DialogWatcher responsive during 1 second sleep period
var count = 0;
while (_keepRunning && count < 5)
{
Thread.Sleep(200);
count++;
}
}
else
{
_keepRunning = false;
}
}
}
public bool IsRunning
{
get { return _watcherThread.IsAlive; }
}
public int ReferenceCount { get; private set; }
/// <summary>
/// Get the last stored exception thrown by a dialog handler while
/// calling the <see cref="IDialogHandler.HandleDialog"/> method of the
/// dialog handler.
/// </summary>
/// <value>The last exception.</value>
public Exception LastException { get; private set; }
/// <summary>
/// If the window is a dialog and visible, it will be passed to
/// the registered dialog handlers. I none if these can handle
/// it, it will be closed if <see cref="CloseUnhandledDialogs"/>
/// is <c>true</c>.
/// </summary>
/// <param name="window">The window.</param>
/// <returns>
/// <c>true</c> if dialog is handled by one of handlers; otherwise, <c>false</c>.
/// </returns>
public bool HandleWindow(Window window)
{
if (!window.IsDialog()) return false;
if (!HasDialogSameProcessNameAsBrowserWindow(window)) return false;
// This is needed otherwise the window Style will return a "wrong" result.
WaitUntilVisibleOrTimeOut(window);
// Lock the thread and see if a handler will handle
// this dialog window
lock (this)
{
foreach (var dialogHandler in _handlers)
{
try
{
if (dialogHandler.CanHandleDialog(window, MainWindow.Hwnd))
{
if (dialogHandler.HandleDialog(window)) return true;
}
}
catch (Exception e)
{
LastException = e;
Logger.LogAction((LogFunction log) => { log("Exception was thrown while DialogWatcher called HandleDialog: {0}",e.ToString()); });
}
}
// If no handler handled the dialog, see if the dialog
// should be closed automatically.
if (!CloseUnhandledDialogs || !MainWindow.Equals(window.ToplevelWindow)) return false;
Logger.LogAction((LogFunction log) => { log("Auto closing dialog with title: '{0}', text: {1}, style: ", window.Title, window.Message, window.StyleInHex); });
window.ForceClose();
}
return false;
}
private bool HasDialogSameProcessNameAsBrowserWindow(Window window)
{
var comparer = new Comparers.StringComparer(window.ProcessName, true);
return comparer.Compare(MainWindow.ProcessName);
}
private static void WaitUntilVisibleOrTimeOut(Window window)
{
// Wait untill window is visible so all properties
// of the window class (like Style and StyleInHex)
// will return valid values.
var tryActionUntilTimeOut = new TryFuncUntilTimeOut(TimeSpan.FromSeconds(Settings.WaitForCompleteTimeOut));
var success = tryActionUntilTimeOut.Try(() => window.Visible);
if (!success)
{
Logger.LogAction((LogFunction log) => { log("Dialog with title '{0}' not visible after {1} seconds.", window.Title, Settings.WaitForCompleteTimeOut); });
}
}
#region IDisposable Members
/// <summary>
/// Performs application-defined tasks associated with freeing, releasing, or
/// resetting unmanaged resources.
/// </summary>
public void Dispose()
{
lock (this)
{
_keepRunning = false;
}
if (IsRunning)
{
_watcherThread.Join();
}
Clear();
}
#endregion
}
}

My team ran into this as well while automating IE8 with WatiN. The problem seems to be with IE, possibly doing some time consuming house-cleaning. The work-around we ultimately used was to invoke a new instance of IE within the outer loop, disposing of it each iteration and then waiting for 5 seconds for whatever was going on in the background to resolve. It was a hack but got the job done.
foreach (var file in lstFiles)
{
string fullFilename = workingDir + "\\" + file;
using (var browser = new IE(fullFilename))
{
//page manipulations...
FileDownloadHandler download = new FileDownloadHandler(fullFilename);
using (new UseDialogOnce(browser.DialogWatcher, download))
{ //lnkFile.ClickNoWait();
download.WaitUntilFileDownloadDialogIsHandled(15);
download.WaitUntilDownloadCompleted(150);
}
}
Thread.Sleep(5000);
}