Form created on BackGroundThread

Collapse
This topic is closed.
X
X
Collapse
 
  • Page of 1
  • Time
  • Show
Clear All
new posts
Previous template Next
  • Pieter
    #1

    Form created on BackGroundThread

    Hi,

    I have some generic module that handles exceptions. simply you call it like
    this: "LogManager.Err orMessage(ex)".

    Worked great, until we now discovered that it isn't Thread-safe. What
    actially happens is this: A Form is made, labels and buttons are made etc
    with the exception-details, but when trying to show the Form
    (MyExceptionFor m.ShowDialog) we get an System.Security .SecurityExcept ion
    (see udnerneath for more info).

    Seems completely normal to me, because we are accessing the UI from another
    Thread. But how to find a solution?


    Thanks a lot in advance,


    Pieter


    PS 1 : I see 2 possiblities:
    1. Call InvokeRequired with Invoke like we usally do when accessing controls
    from another thread
    (http://msdn.microsoft.com/en-us/libr...8(VS.80).aspx). BUT:
    MyExceptionForm .InvokeRequired returns false... I guess this is because it
    has been constructed in a background Thread?
    2. To get around this problem: Figure out when we are on a background thread
    (via Threading.Threa d.CurrentThread .IsBackground: is this true??) and than
    get via an event an an Invoke or something like that on the Main-htread and
    call the form from there?
    3. ...


    PS 2: The exception when doing a MyExceptionForm .ShowDialog:
    System.Security .SecurityExcept ion was caught
    Message="Reques t for the permission of type
    'System.Securit y.Permissions.U IPermission, mscorlib, Version=2.0.0.0 ,
    Culture=neutral , PublicKeyToken= b77a5c561934e08 9' failed."
    Source="mscorli b"
    StackTrace:
    at System.Security .CodeAccessSecu rityEngine.Chec k(Object demand,
    StackCrawlMark& stackMark, Boolean isPermSet)
    at System.Security .CodeAccessPerm ission.Demand()
    at System.Windows. Forms.NativeWin dow.CreateHandl e(CreateParams cp)
    at System.Windows. Forms.Control.C reateHandle()
    at System.Windows. Forms.Form.Crea teHandle()
    at System.Windows. Forms.Control.g et_Handle()
    at
    System.Windows. Forms.Applicati on.ThreadContex t.RunMessageLoo pInner(Int32
    reason, ApplicationCont ext context)
    at
    System.Windows. Forms.Applicati on.ThreadContex t.RunMessageLoo p(Int32 reason,
    ApplicationCont ext context)
    at System.Windows. Forms.Form.Show Dialog(IWin32Wi ndow owner)
    at System.Windows. Forms.Form.Show Dialog()
    at LoggingManager. LogManager.Exce ptionToUI(LogEx ception MyException)




    Tags: None
    • Patrice
      #2
      Re: Form created on BackGroundThrea d

      And you call it using ? Do you want your application to continue in case of
      an unexpected exception ?

      You have also an event that is part of the application framework
      (Application_Un handledExceptio n from the top of my head) and that could
      well work even for background thread.

      --
      Patrice

      "Pieter" <pieterNOSPAMco ucke@hotmail.co ma écrit dans le message de groupe
      de discussion : uyi3LUvyIHA.489 6@TK2MSFTNGP03. phx.gbl...
      Hi,
      >
      I have some generic module that handles exceptions. simply you call it
      like this: "LogManager.Err orMessage(ex)".
      >
      Worked great, until we now discovered that it isn't Thread-safe. What
      actially happens is this: A Form is made, labels and buttons are made etc
      with the exception-details, but when trying to show the Form
      (MyExceptionFor m.ShowDialog) we get an System.Security .SecurityExcept ion
      (see udnerneath for more info).
      >
      Seems completely normal to me, because we are accessing the UI from
      another Thread. But how to find a solution?
      >
      >
      Thanks a lot in advance,
      >
      >
      Pieter
      >
      >
      PS 1 : I see 2 possiblities:
      1. Call InvokeRequired with Invoke like we usally do when accessing
      controls from another thread
      (http://msdn.microsoft.com/en-us/libr...8(VS.80).aspx). BUT:
      MyExceptionForm .InvokeRequired returns false... I guess this is because it
      has been constructed in a background Thread?
      2. To get around this problem: Figure out when we are on a background
      thread (via Threading.Threa d.CurrentThread .IsBackground: is this true??)
      and than get via an event an an Invoke or something like that on the
      Main-htread and call the form from there?
      3. ...
      >
      >
      PS 2: The exception when doing a MyExceptionForm .ShowDialog:
      System.Security .SecurityExcept ion was caught
      Message="Reques t for the permission of type
      'System.Securit y.Permissions.U IPermission, mscorlib, Version=2.0.0.0 ,
      Culture=neutral , PublicKeyToken= b77a5c561934e08 9' failed."
      Source="mscorli b"
      StackTrace:
      at System.Security .CodeAccessSecu rityEngine.Chec k(Object demand,
      StackCrawlMark& stackMark, Boolean isPermSet)
      at System.Security .CodeAccessPerm ission.Demand()
      at System.Windows. Forms.NativeWin dow.CreateHandl e(CreateParams cp)
      at System.Windows. Forms.Control.C reateHandle()
      at System.Windows. Forms.Form.Crea teHandle()
      at System.Windows. Forms.Control.g et_Handle()
      at
      System.Windows. Forms.Applicati on.ThreadContex t.RunMessageLoo pInner(Int32
      reason, ApplicationCont ext context)
      at
      System.Windows. Forms.Applicati on.ThreadContex t.RunMessageLoo p(Int32
      reason, ApplicationCont ext context)
      at System.Windows. Forms.Form.Show Dialog(IWin32Wi ndow owner)
      at System.Windows. Forms.Form.Show Dialog()
      at LoggingManager. LogManager.Exce ptionToUI(LogEx ception MyException)
      >
      >
      >
      >

        Comment

        • Pieter
          #3
          Re: Form created on BackGroundThrea d

          I put this line "LogManager.Err orMessage(ex)" in every Try-Catch-block (in
          the catch offcourse :-) ).
          So what it actually does is: it writes the error in a database, sends it via
          an email, and shows it on the screen. But showing on the screen only works
          when the exception handled on the GUI-thread. so I want it be shown always,
          whiwhever thread was used...

          "Patrice" <http://www.chez.com/scribe/wrote in message
          news:87343D0D-E79C-4276-8254-F9D82CBDDFE8@mi crosoft.com...
          And you call it using ? Do you want your application to continue in case
          of an unexpected exception ?
          >
          You have also an event that is part of the application framework
          (Application_Un handledExceptio n from the top of my head) and that could
          well work even for background thread.
          >
          --
          Patrice

            Comment

            • Patrice
              #4
              Re: Form created on BackGroundThrea d

              And do you still continue ?

              My personal preference instead of catching unexpected errors would be to use
              this (global) event that could well handle nicely threading. You can keep a
              try block without a catch clause if you want to clean up resources before
              your handler runs...

              This way you shouldn"t have to care about threading issues and you don't
              have to explicitely try/catch everywhere unless you really need...

              If you keep this design, it seems a bit weird as the message usually clearly
              state this is a threading issue. Here it would make me think rather to a
              click once application that doesn't have some UI permissions (don't remember
              the details but by default you have some security restrictions applied to
              clickonce applications). Is this a clickonce deployed application ?

              What if you try to create fresh a small repro. Do you have the same behavior
              ?

              --
              Patrice

              "Pieter" <pieterNOSPAMco ucke@hotmail.co ma écrit dans le message de groupe
              de discussion : #Xvhc8vyIHA.206 8@TK2MSFTNGP05. phx.gbl...
              I put this line "LogManager.Err orMessage(ex)" in every Try-Catch-block (in
              the catch offcourse :-) ).
              So what it actually does is: it writes the error in a database, sends it
              via an email, and shows it on the screen. But showing on the screen only
              works when the exception handled on the GUI-thread. so I want it be shown
              always, whiwhever thread was used...
              >
              "Patrice" <http://www.chez.com/scribe/wrote in message
              news:87343D0D-E79C-4276-8254-F9D82CBDDFE8@mi crosoft.com...
              >And you call it using ? Do you want your application to continue in case
              >of an unexpected exception ?
              >>
              >You have also an event that is part of the application framework
              >(Application_U nhandledExcepti on from the top of my head) and that could
              >well work even for background thread.
              >>
              >--
              >Patrice
              >
              >

                Comment

                • Patrice
                  #5
                  Re: Form created on BackGroundThrea d

                  The strange thing is that the message looks like a UI restricted ClickOnce
                  operation
                  (http://msdn.microsoft.com/en-us/libr...rmission.aspx).
                  Is this a ClickOnce applciation ? Does it have fulltrust ?

                  When this is a cross thread operation the exception is an
                  InvalidOperatio nException and is much more explicit (translated from french
                  "Invalid Cross Thread operation : the control "Blah" is being access by
                  another thread than the one who created it"). You are using .NET 2.0 ?

                  My first move would be likely to create a new application as simple as
                  possible that throwns in a background thread to see if I have the same
                  behavior.

                  --
                  Patrice


                  "Pieter" <pieterNOSPAMco ucke@hotmail.co ma écrit dans le message de groupe
                  de discussion : #Xvhc8vyIHA.206 8@TK2MSFTNGP05. phx.gbl...
                  I put this line "LogManager.Err orMessage(ex)" in every Try-Catch-block (in
                  the catch offcourse :-) ).
                  So what it actually does is: it writes the error in a database, sends it
                  via an email, and shows it on the screen. But showing on the screen only
                  works when the exception handled on the GUI-thread. so I want it be shown
                  always, whiwhever thread was used...
                  >
                  "Patrice" <http://www.chez.com/scribe/wrote in message
                  news:87343D0D-E79C-4276-8254-F9D82CBDDFE8@mi crosoft.com...
                  >And you call it using ? Do you want your application to continue in case
                  >of an unexpected exception ?
                  >>
                  >You have also an event that is part of the application framework
                  >(Application_U nhandledExcepti on from the top of my head) and that could
                  >well work even for background thread.
                  >>
                  >--
                  >Patrice
                  >
                  >

                    Comment

                    • Pieter
                      #6
                      Re: Form created on BackGroundThrea d

                      Hi Patrice,

                      Thansk a lot for your efforts!

                      It's a VB.NET 2.0 Windows Forms application.
                      We have this problem whenever we want to show the form, when the exception
                      happened on a Thread other than the one of the GUI.
                      I'm quit sure it doesn't has any to do with permissions, because of these 2
                      reasons:
                      - If we run the same code on the GUI thread and generate an exception there,
                      it shows it nicely.
                      - If even happens when trying to do a Cursor.Current =
                      System.Windows. Forms.Cursors.W aitCursor
                      Although, I didn't test it yet with some sampel application if it really has
                      only something to do with a different Thread. We noticed it because of an
                      error generated by the ReportViewer (which uses another Thread). And because
                      the exception-handlign screw up whenever it accessed the GUI, I presumed it
                      was because of this... I'll try to isolate the problem...

                      Handlign the exceptions in another way won't be possible unfortunately.


                      Pieter


                      "Patrice" <http://www.chez.com/scribe/wrote in message
                      news:4E157960-BA02-4957-AAB8-929CEE8A979B@mi crosoft.com...
                      The strange thing is that the message looks like a UI restricted ClickOnce
                      operation
                      (http://msdn.microsoft.com/en-us/libr...rmission.aspx).
                      Is this a ClickOnce applciation ? Does it have fulltrust ?
                      >
                      When this is a cross thread operation the exception is an
                      InvalidOperatio nException and is much more explicit (translated from
                      french "Invalid Cross Thread operation : the control "Blah" is being
                      access by another thread than the one who created it"). You are using .NET
                      2.0 ?
                      >
                      My first move would be likely to create a new application as simple as
                      possible that throwns in a background thread to see if I have the same
                      behavior.
                      >
                      --
                      Patrice
                      >
                      >
                      "Pieter" <pieterNOSPAMco ucke@hotmail.co ma écrit dans le message de
                      groupe de discussion : #Xvhc8vyIHA.206 8@TK2MSFTNGP05. phx.gbl...
                      >I put this line "LogManager.Err orMessage(ex)" in every Try-Catch-block
                      >(in the catch offcourse :-) ).
                      >So what it actually does is: it writes the error in a database, sends it
                      >via an email, and shows it on the screen. But showing on the screen only
                      >works when the exception handled on the GUI-thread. so I want it be shown
                      >always, whiwhever thread was used...
                      >>
                      >"Patrice" <http://www.chez.com/scribe/wrote in message
                      >news:87343D0 D-E79C-4276-8254-F9D82CBDDFE8@mi crosoft.com...
                      >>And you call it using ? Do you want your application to continue in case
                      >>of an unexpected exception ?
                      >>>
                      >>You have also an event that is part of the application framework
                      >>(Application_ UnhandledExcept ion from the top of my head) and that could
                      >>well work even for background thread.
                      >>>
                      >>--
                      >>Patrice
                      >>
                      >>
                      >

                        Comment

                        • Pieter
                          #7
                          Re: Form created on BackGroundThrea d

                          Hi,

                          Apparently it isn't because of a different Threa,d but specific to the
                          Reportviewer. We found the needed information o nthis site:
                          Mohamed Sharaf's Blog
                          http://blogs.msdn.com/mosharaf/archive/2005/12/20/LocalReportCustomCode.aspx

                          and solved the problem by addign simply this line of code before rendering
                          the Report:
                          Me.rpvwReport.L ocalReport.Exec uteReportInCurr entAppDomain(Ap pDomain.Current Domain.Evidence )



                          Thanks for the help! :-)


                          "Patrice" <http://www.chez.com/scribe/wrote in message
                          news:4E157960-BA02-4957-AAB8-929CEE8A979B@mi crosoft.com...
                          The strange thing is that the message looks like a UI restricted ClickOnce
                          operation
                          (http://msdn.microsoft.com/en-us/libr...rmission.aspx).
                          Is this a ClickOnce applciation ? Does it have fulltrust ?
                          >
                          When this is a cross thread operation the exception is an
                          InvalidOperatio nException and is much more explicit (translated from
                          french "Invalid Cross Thread operation : the control "Blah" is being
                          access by another thread than the one who created it"). You are using .NET
                          2.0 ?
                          >
                          My first move would be likely to create a new application as simple as
                          possible that throwns in a background thread to see if I have the same
                          behavior.
                          >
                          --
                          Patrice
                          >
                          >
                          "Pieter" <pieterNOSPAMco ucke@hotmail.co ma écrit dans le message de
                          groupe de discussion : #Xvhc8vyIHA.206 8@TK2MSFTNGP05. phx.gbl...
                          >I put this line "LogManager.Err orMessage(ex)" in every Try-Catch-block
                          >(in the catch offcourse :-) ).
                          >So what it actually does is: it writes the error in a database, sends it
                          >via an email, and shows it on the screen. But showing on the screen only
                          >works when the exception handled on the GUI-thread. so I want it be shown
                          >always, whiwhever thread was used...
                          >>
                          >"Patrice" <http://www.chez.com/scribe/wrote in message
                          >news:87343D0 D-E79C-4276-8254-F9D82CBDDFE8@mi crosoft.com...
                          >>And you call it using ? Do you want your application to continue in case
                          >>of an unexpected exception ?
                          >>>
                          >>You have also an event that is part of the application framework
                          >>(Application_ UnhandledExcept ion from the top of my head) and that could
                          >>well work even for background thread.
                          >>>
                          >>--
                          >>Patrice
                          >>
                          >>
                          >

                            Comment

                            • Patrice
                              #8
                              Re: Form created on BackGroundThrea d

                              Great you solved it and thanks for letting us know what caused the
                              problem...

                              --
                              Patrice

                              "Pieter" <pieterNOSPAMco ucke@hotmail.co ma écrit dans le message de groupe
                              de discussion : e7bf8g6yIHA.238 4@TK2MSFTNGP02. phx.gbl...
                              Hi,
                              >
                              Apparently it isn't because of a different Threa,d but specific to the
                              Reportviewer. We found the needed information o nthis site:
                              Mohamed Sharaf's Blog
                              http://blogs.msdn.com/mosharaf/archive/2005/12/20/LocalReportCustomCode.aspx

                              and solved the problem by addign simply this line of code before rendering
                              the Report:
                              Me.rpvwReport.L ocalReport.Exec uteReportInCurr entAppDomain(Ap pDomain.Current Domain.Evidence )
                              >
                              >
                              >
                              Thanks for the help! :-)
                              >
                              >
                              "Patrice" <http://www.chez.com/scribe/wrote in message
                              news:4E157960-BA02-4957-AAB8-929CEE8A979B@mi crosoft.com...
                              >The strange thing is that the message looks like a UI restricted
                              >ClickOnce operation
                              >(http://msdn.microsoft.com/en-us/libr...rmission.aspx).
                              >Is this a ClickOnce applciation ? Does it have fulltrust ?
                              >>
                              >When this is a cross thread operation the exception is an
                              >InvalidOperati onException and is much more explicit (translated from
                              >french "Invalid Cross Thread operation : the control "Blah" is being
                              >access by another thread than the one who created it"). You are using
                              >.NET 2.0 ?
                              >>
                              >My first move would be likely to create a new application as simple as
                              >possible that throwns in a background thread to see if I have the same
                              >behavior.
                              >>
                              >--
                              >Patrice
                              >>
                              >>
                              >"Pieter" <pieterNOSPAMco ucke@hotmail.co ma écrit dans le message de
                              >groupe de discussion : #Xvhc8vyIHA.206 8@TK2MSFTNGP05. phx.gbl...
                              >>I put this line "LogManager.Err orMessage(ex)" in every Try-Catch-block
                              >>(in the catch offcourse :-) ).
                              >>So what it actually does is: it writes the error in a database, sends it
                              >>via an email, and shows it on the screen. But showing on the screen only
                              >>works when the exception handled on the GUI-thread. so I want it be
                              >>shown always, whiwhever thread was used...
                              >>>
                              >>"Patrice" <http://www.chez.com/scribe/wrote in message
                              >>news:87343D 0D-E79C-4276-8254-F9D82CBDDFE8@mi crosoft.com...
                              >>>And you call it using ? Do you want your application to continue in
                              >>>case of an unexpected exception ?
                              >>>>
                              >>>You have also an event that is part of the application framework
                              >>>(Application _UnhandledExcep tion from the top of my head) and that
                              >>>could well work even for background thread.
                              >>>>
                              >>>--
                              >>>Patrice
                              >>>
                              >>>
                              >>
                              >
                              >

                                Comment

                                Previous template Next
                                Working...