Develop Reference

Problem with installing chocolatey files with task.run on windows 8.1

I'm tasked with creating a tool to help set up customers systems easily. I've created a function that calls a chocolatey script through powershell in c# and I use Task.run to create a new thread so it doesn't affect the UI thread, The system works fine, but I'm having problems with some computers. It's not helped that I have no access to these computers and do not know much about their system, and due to time constraints do not have access to these computers. I do know they have windows 8.1. I was given a windows 10 virtual machine to test on (which I still don't understand as it was known that this was a windows 8 problem)
Here is the code.
I know for a fact(due to the one time I was given access to these computers) that it stops on Task.Run(() => task)
Does anyone know if there are any problems with either chocolatey or Tasks on windows 8.1?
Task callTask = Task.Run(() => ExecuteAsynchronouslyAsync("chocolatey string", CheckBox box, string logName));
public async Task<PowerShellAction> ExecuteAsynchronouslyAsync(String commandStr, CheckBox box, string logName)
{
powerShellAction = new PowerShellAction();
powerShellAction.isFinished = false;
using (PowerShell ps = PowerShell.Create())
{
ps.AddScript(commandStr); // adding the script to the powershell script.
outputCollection = new PSDataCollection<PSObject>();
outputCollection.DataAdded += OutputData;
IAsyncResult result = ps.BeginInvoke<PSObject, PSObject>(null, outputCollection);
PSDataCollection<PSObject> execRes = await Task.Factory.FromAsync(result, ps.EndInvoke);
}
return powerShellAction;
}
Working right now on trying to get a virtual machine of 8.1 to continue trying to debug myself. Any other suggestions would be welcome.

Unfortunately I cannot ensure that my suggestions are correct. The main reason is, that i can't figure out what PowerShellAction is supposed to be. I'm assuming here that PowerShell is System.Management.Automation.PowerShell.
I'm suggesting several things:
Your code does not compile for several reasons: you have no var or type-declaration on the first line of your method and the method-call would not work because of the addition string keyword. Try to avoid pasting in code like yours in the future please because it's pretty hard to rebuild your sample.
Don't bypass a UI control to an async method but use the needed value (e.g. box.IsChecked as a bool) instead.
Add ConfigureAwait(false) to your await to prevent .NET from trying to sync back to the context.
Take more care about exception handling insude of your method.
Dont' return anything if you don't need it in your method.
The code (untestet) could be something like this:
var task = Task.Run(() => ExecutePowerShellAsync("chocolatey string", box.IsChecked, "NameOfTheLog"));
public async Task<PowerShellAction> ExecutePowerShellAsync(String commandStr, bool checkBoxValue, string logName)
{
var powerShellAction = new PowerShellAction();
powerShellAction.isFinished = false;
using (PowerShell ps = PowerShell.Create())
{
ps.AddScript(commandStr); // adding the script to the powershell script.
var outputCollection = new PSDataCollection<PSObject>();
outputCollection.DataAdded += OutputData;
IAsyncResult result = ps.BeginInvoke<PSObject, PSObject>(null, outputCollection);
PSDataCollection<PSObject> execRes = await Task.Factory.FromAsync(result, ps.EndInvoke).ContinueWith(t => {
if (t.IsFaulted)
{
System.Diagnostics.Trace.TraceError("Task faulted with exception: " + t.Exception?.Message);
}
return t.Result;
}).ConfigureAwait(false);
}
return powerShellAction;
}
I use ContinueWith in order to be able to react to any exception that might occur inside the original task.
I'm suggesting this because your description smells like you have a typical thread-lock which means the code simple does not come back due to an exception or context-syncing-problems.

Universal Windows App Background Task "has exited with code 1 (0x1)"

Scratching my head on this one.
I've got a background task in my UWP application which is registered to run every 15 minutes (using TimeTrigger) and whenever the internet becomes available (using a SystemTrigger). I know for a fact that these are registered correctly as both appear in the "Lifecycle Events" when debugging using visual studio. Nevertheless, my code for registering them is below:
bool registered1 = false;
bool registered2 = false;
foreach (var task in BackgroundTaskRegistration.AllTasks)
{
if (task.Value.Name == "BackgroundGPS")
{
registered1 = true;
}
if (task.Value.Name == "InternetAvailGPS")
{
registered2 = true;
}
}
await BackgroundExecutionManager.RequestAccessAsync();
if (!registered1)
{
var builder1 = new BackgroundTaskBuilder();
builder1.Name = "BackgroundGPS";
builder1.TaskEntryPoint = "BackgroundTasks.BackgroundGPSTask";
var triggerTime = new TimeTrigger(15, false);
builder1.SetTrigger(triggerTime);
BackgroundTaskRegistration task1 = builder1.Register();
}
if (!registered2)
{
var builder2 = new BackgroundTaskBuilder();
builder2.Name = "InternetAvailGPS";
builder2.TaskEntryPoint = "BackgroundTasks.BackgroundGPSTask";
var triggerIA = new SystemTrigger(SystemTriggerType.InternetAvailable, false);
builder2.SetTrigger(triggerIA);
BackgroundTaskRegistration task2 = builder2.Register();
}
I have ensured that the tasks are declared correctly in my manifest. If they weren't, my app would be throwing an exception when trying to register them.
If I run in debug mode I can see that both BackgroundGPS and InternetAvailGPS are shown in the Lifecycle Events. However, when I click on either of them to force them to execute, I get the following in the output window:
The program '[4728] backgroundTaskHost.exe' has exited with code 1 (0x1).
I have a breakpoint set at the first line of code in my 'Run' method of the background task but this is never hit. The background task is never loaded nor run, and I've no idea why. This probably isn't an issue with my Run method, but it looks like this (I've omitted much of the meat of it, and just included the beginning and end)
public async void Run(IBackgroundTaskInstance taskInstance)
{
Debug.WriteLine("GPS Started");
int errCode = 0;
try
{
_deferral = taskInstance.GetDeferral();
saveGPSStatus(DateTime.Now.ToString(), "", " ");
var access = await Geolocator.RequestAccessAsync();
if (access != GeolocationAccessStatus.Allowed)
{
Debug.WriteLine("No access");
saveGPSStatus("", "", "No GPS Access");
return;
}
Geolocator locator = new Geolocator();
locator.DesiredAccuracyInMeters = 100;
Geoposition position = await locator.GetGeopositionAsync();
//Stuff goes on in here
_deferral.Complete();
}
catch (Exception e)
{
Debug.WriteLine(e.Message);
saveGPSStatus("", "", "Unexpected error. Err code "+errCode+". " + e.Message);
_deferral.Complete();
}
}
I have tried this both on a Windows Phone and a Windows Tablet both running build 10.0.10586.164, and they both do not execute my background task.
As I said above, these were working perfectly a few weeks ago and have only realised something was wrong as some of the app's users have been complaining!
Any help is greatly appreciated.

Got it working in the end, I was simply missing a reference to my background task project within my main project. I must have deleted it by accident at some point before that.

Just to expand on not having it referenced, not having the correct TaskEntryPoint namespace and class name will also cause this error. For me, I misspelt the class name.

How do I make my application responsive during Entity Framework operations?

I have a fairly simple WPF application that uses Entity Framework. The main page of the application has a list of records that I am getting from a database on startup.
Each record has a picture, so the operation can be a little slow when the wireless signal is poor. I'd like this (and many of my SQL operations) to perform in the background if possible. I have async/await setup and at first it seemed to be working exactly as I wanted but now I'm seeing that my application is becoming unresponsive when accessing the DB.
Eventually I'm thinking I'm going to load up the text in one query and the images in another background operation and load them as they come in. This way I get the important stuff right away and the pictures can come in in the background, but the way things are going it's still looking like it will lock up if I do this.
On top of that, I'm trying to implement something to handle connectivity issues (in case the wifi cuts out momentarily) so that the application notifies the user of a connection issue, automatically retries a few times, etc. I put a try catch for SQL exception which seems to be working for me, but the whole application locks up for about a minute while it is trying to connect to the DB.
I tried testing my async/await using await Task.Delay() and everything is very responsive as expected while awaiting the delay, but everything locks up when awaiting the .ToListAsync(). Is this normal and expected? My understanding of async/await is pretty limited.
My code is kind of messy (I'm new) but it does what I need it to do for the most part. I understand there's probably plenty of improvements I can make and better ways to do things, but one step at a time here. My main goal right now is to keep the application from crashing during database accessing exceptions and to keep the user notified of what the application is doing (searching, trying to access db, unable to reach DB and retrying, etc) as opposed to being frozen, which is what they're going to think when they see it being unresponsive for over a minute.
Some of my code:
In my main view model
DataHelper data = new DataHelper();
private async void GetQualityRegisterQueueAsync()
{
try
{
var task = data.GetQualityRegisterAsync();
IsSearching = true;
await task;
IsSearching = false;
QualityRegisterItems = new ObservableCollection<QualityRegisterQueue>(task.Result);
OrderQualityRegisterItems();
}
catch (M1Exception ex)
{
Debug.WriteLine(ex.Message);
Debug.WriteLine("QualityRegisterLogViewModel.GetQualityRegisterQueue() Operation Failed");
}
}
My Data Helper Class
public class DataHelper
{
private bool debugging = false;
private const int MAX_RETRY = 2;
private const double LONG_WAIT_SECONDS = 5;
private const double SHORT_WAIT_SECONDS = 0.5;
private static readonly TimeSpan longWait = TimeSpan.FromSeconds(LONG_WAIT_SECONDS);
private static readonly TimeSpan shortWait = TimeSpan.FromSeconds(SHORT_WAIT_SECONDS);
private enum RetryableSqlErrors
{
ServerNotFound = -1,
Timeout = -2,
NoLock = 1204,
Deadlock = 1205,
}
public async Task<List<QualityRegisterQueue>> GetQualityRegisterAsync()
{
if(debugging) await Task.Delay(5000);
var retryCount = 0;
using (M1Context m1 = new M1Context())
{
for (; ; )
{
try
{
return await (from a in m1.QualityRegisters
where (a.qanClosed == 0)
//orderby a.qanAssignedDate descending, a.qanOpenedDate
orderby a.qanAssignedDate.HasValue descending, a.qanAssignedDate, a.qanOpenedDate
select new QualityRegisterQueue
{
QualityRegisterID = a.qanQualityRegisterID,
JobID = a.qanJobID.Trim(),
JobAssemblyID = a.qanJobAssemblyID,
JobOperationID = a.qanJobOperationID,
PartID = a.qanPartID.Trim(),
PartRevisionID = a.qanPartRevisionID.Trim(),
PartShortDescription = a.qanPartShortDescription.Trim(),
OpenedByEmployeeID = a.qanOpenedByEmployeeID.Trim(),
OpenedByEmployeeName = a.OpenedEmployee.lmeEmployeeName.Trim(),
OpenedDate = a.qanOpenedDate,
PartImage = a.JobAssembly.ujmaPartImage,
AssignedDate = a.qanAssignedDate,
AssignedToEmployeeID = a.qanAssignedToEmployeeID.Trim(),
AssignedToEmployeeName = a.AssignedEmployee.lmeEmployeeName.Trim()
}).ToListAsync();
}
catch (SqlException ex)
{
Debug.WriteLine("SQL Exception number = " + ex.Number);
if (!Enum.IsDefined(typeof(RetryableSqlErrors), ex.Number))
throw new M1Exception(ex.Message, ex);
retryCount++;
if (retryCount > MAX_RETRY) throw new M1Exception(ex.Message, ex); ;
Debug.WriteLine("Retrying. Count = " + retryCount);
Thread.Sleep(ex.Number == (int)RetryableSqlErrors.Timeout ?
longWait : shortWait);
}
}
}
}
}
Edit: Mostly looking for general guidance here, though a specific example of what to do would be great. For these types of operations where I am downloading data, is it just a given that if I need the application to be responsive I need to be making multiple threads? Is that a common solution to this type of problem? Is this not something I should be expecting async/await to solve?

If you call this method from your UI thread, you will overload the capture of UI thread context and back on itself. Also, your service will not be necessarily "Performant" because it must wait until the UI thread is free before it can continue.
The solution is simple: just call the method passing the ConfigureAwait "false" parameter when you made the call.
.ToListAsync().ConfigureAwaiter(false);
I hope it helps

Powershell endinvoke function gets stuck under heavy load

My application is written in c# and uses Powershell class of .net library. It is multi-threaded and can execute a bunch of powershell scripts simultaneously on a runspacepool.
I use a runspacepool size of 100. Before the execution of each script I create a session to the target computer, by using the code below.
I use BeginInvoke to start execution in a pipeline and end-invoke to get the results, which include the session.
ps = PowerShell.Create()
var sessionScript = new PSCommand();
sessionScript.AddCommand(New-PSSession);
sessionScript.AddParameter("ConnectionUri", "http://192.xxx.x.xxx:5985";);
sessionScript.AddParameter("AllowRedirection");
var sessOpt = new System.Management.Automation.Remoting.PSSessionOption();
sessOpt.OpenTimeout = new TimeSpan(0,0,0,0, 120000);
sessOpt.CancelTimeout = new TimeSpan(0, 0, 0, 0,120000);
sessionScript.AddParameter("SessionOption", sessOpt);
var cred = new PSCredential(uName, password);
sessionScript.AddParameter("Credential", cred);
ps.Commands = sessionScript
ps.RunSpacePool = mypool ## size 100 created earlier
asyncResult = ps.BeginInvoke();
resultsOut = ps.EndInvoke(asyncResult);
All is fine when I keep my number of parallel executing sessions below 100. Once in a while when I hit 100 and above, I notice one or two threads (.net tasks) just getting stuck. I did some debugging and realized that the thread was getting stuck for EndInvoke. Even after a week the call just didn't return and the thread was still alive.
So, I replaced execution code by adding a Timer to this operation
Timer taskTimer = new Timer(TaskHitTimeout, null , 120000, System.Threading.Timeout.Infinite);
asyncResult = ps.BeginInvoke();
while (true)
{
if (asyncResult.IsCompleted || this.isCancelled)
break;
Thread.Sleep(200);
}
if (!this.isCancelled)
resultsOut = ps.EndInvoke(asyncResult);
and in the TimerHandler I set isCancelled to True
private void TaskHitTimeout(Object statusCode)
{ this.isCancelled = True;}
This did fix my problem. But I would like to understand why the call to EndInvoke just doesn't return. Is there anything else I can do to improve this. And If anyone else has seen a similar issue.

Calling SSIS package Asynchronously

I'm calling a SSIS package using LoadPackage(...).
Is it possible to make this call an Asynchronous call?

Yes, use an asynchronous delegate, as demostrated here:
http://msdn.microsoft.com/en-us/library/h80ttd5f.aspx

If you just want it to run in the background then yes, you can either spool up a thread or call some T-SQL to dynamically create a job (and remove it again afterwards). If you want to run it asynchronously and want a callback when it's done, then I think you're out of luck unfortunately.

Are you asking if it's 1) legal to call LoadPackage on a background thread or 2) is it possible. For #1 I can't give a definitive answer because I don't use the SSIS framework.
However #2 (as long as #1 is true) is definately doable. IMHO, you're better off using an existing framework which has API's designed to calling API's async and waiting for the results. For instance with Parellel Extensions June 08 CTP, the following code will do.
using System.Threading.Tasks;
...
var future = Future.Create(()=>LoadPackage); // Starts loading the package
// Do other stuff
var package = future.Value; // Wait for package load to complete and get the value

I'm calling an SSIS package from my UI (WPF) via an async WCF service call. Service code is:
public string ImportMarriageXML(bool isWakeUp, bool clearExistingMarriage)
{
try
{
var dts = new Microsoft.SqlServer.Dts.Runtime.Application();
using (var package = dts.LoadFromSqlServer(
ServiceSettings.Settings.SSIS.ImportMarriages,
ServiceSettings.Settings.SSIS.ServerIP,
ServiceSettings.Settings.SSIS.UserID,
ServiceSettings.Settings.SSIS.Password,
null))
{
package.InteractiveMode = false;
package.Connections["DB.STAGING"].ConnectionString = String.Format("{0};Provider={1};", DBSettings.ConnectionString(Core.Database.Staging), ServiceSettings.Settings.SSIS.Provider);
var variables = package.Variables;
variables["IsWakeUp"].Value = isWakeUp;
variables["ClearExistingMarriage"].Value = clearExistingMarriage;
variables["XmlDirectory"].Value = ServiceSettings.Settings.SSIS.Properties.XmlDirectory;
if (package.Execute() == DTSExecResult.Failure)
{
// HACK: Need to refactor this at some point. Will do for now.
var errors = new System.Text.StringBuilder();
foreach (var error in package.Errors)
errors.AppendFormat("SubComponent: {0}; Description: {1}{2}", error.SubComponent, error.Description, Environment.NewLine);
throw new ApplicationException(errors.ToString());
}
return package.Connections["Text Logging"].ConnectionString;
}
}
}
And (part of) the client-side code is as follows:
private void InvokeLoadMarriages()
{
integrationServicesServiceClient.BeginImportMarriageXML(false, OnEndImportMarriageXML, null);
}
private void OnEndImportMarriageXML(IAsyncResult asyncResult)
{
view.InvokeDisplayResults(integrationServicesServiceClient.EndImportMarriageXML(asyncResult));
}
Where BeginImportMarriageXML & EndImportMarriageXML are the generated async operations in the proxy class.