Tracing problem. Lock()

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

    Tracing problem. Lock()

    My application runs for a while then just stops completely. No stack
    overflows or any other errors, visual studio doesn't report any problems. I
    can close the application down ok from the studio toolbar. If I check Task
    Manager, CPU is 0%, memory changes a little over time.
    I constantly log application flow to the output pane. Logging stops, usually
    only a portion of the "current" debug string is displayed ie the thread
    that's writing to the output pane is just stopping too.
    There's several threads, originating from system.thread.t imer objects.
    Variables that are shared across threads are protected by Lock().

    I wondered if this is a problem caused by locks, so to test I added
    "entering lock", "locked", "unlocked" around every Lock(){} call.
    I'm having trouble debugging this. Are there any tools out there that can
    tell the state of locked threads?

    thanks


    Tags: None
    • Helge Jensen
      #2
      Re: Tracing problem. Lock()



      Claire wrote:[color=blue]
      > My application runs for a while then just stops completely. No stack
      > overflows or any other errors, visual studio doesn't report any problems. I[/color]

      You do know you can break it in the debugger (or attach to it) and
      inspect each threads state, callstack, ...

      --
      Helge Jensen
      mailto:helge.je nsen@slog.dk
      sip:helge.jense n@slog.dk
      -=> Sebastian cover-music: http://ungdomshus.nu <=-

        Comment

        • Claire
          #3
          Re: Tracing problem. Lock()

          If I break in, it stops on the "Application.Ru n(form1);" line
          In a multithreaded application (3 main threads plus other threads entering
          at the end of timer timeout period) why would every thread stop concurrently
          like that?
          I could understand 2 threads competing for a lock but the remainder should
          continue shouldn't they?



            Comment

            • Helge Jensen
              #4
              Re: Tracing problem. Lock()



              Claire wrote:[color=blue]
              > If I break in, it stops on the "Application.Ru n(form1);" line
              > In a multithreaded application (3 main threads plus other threads entering
              > at the end of timer timeout period) why would every thread stop concurrently
              > like that?[/color]

              Inspect the call-stack of *all* the threads.

              If all your other threads are waiting for timers, then nothing is going
              to happen untill a timer fires, or some windows message is sent to your
              form.

              The main thread is probably stuck in Application.Run since no windows
              messages are being passed to your form at the moment you break.
              [color=blue]
              > I could understand 2 threads competing for a lock but the remainder should
              > continue shouldn't they?[/color]

              If they are waiting for a timer to elapse, they *are* running.

              If the threads we awaiting a "lock" I would expect to see that at some
              point in their call-stacks.

              Event-driven programs doesn't "run" untill there is an event to react
              to. If nobody generates any events -- nothing happens.

              BTW: It's hard to generate GUI-event while running in the debugger. You
              can make a button that does something and set a breakpoint in the
              handler for it.

              --
              Helge Jensen
              mailto:helge.je nsen@slog.dk
              sip:helge.jense n@slog.dk
              -=> Sebastian cover-music: http://ungdomshus.nu <=-

                Comment

                • The Crow
                  #5
                  Re: Tracing problem. Lock()

                  u can view running threads state. Press ctrl+alt+H or ctrl+shift+H. i dont
                  remeber which one.


                    Comment

                    Previous template Next
                    Working...