Mes: noviembre 2009

Escribiendo código concurrente de alto rendimiento con monitores

Las aplicaciones multi hilo o concurrentes van a ser el siguiente gran problema para los desarrolladores, y tenemos que estar listos para este cambio tan grade. En el .NET Framework 4, Microsoft incluye una serie de nuevas APIs que ayudan al desarrollador en la creación de aplicaciones concurrentes. Eso no significa que tengamos que despreocuparnos del código concurrente sino que a partir de ahora va a ser más fácil hacerlo.

Actualmente estoy trabajando en una aplicación que hace un uso intensivo de la API de TPL. Básicamente la aplicación genera una serie de Task que administran la ejecución de una serie de reglas aplicadas a una Uri. Además de eso mantengo una lista con la colección de Task creadas por mi aplicación, para contabilizar cuantas están ejecutándose y una serie de estadísticas de velocidad de la aplicación.

Esto significa que tenemos una UI donde vamos mostrando los datos, creada en WPF 4 que necesita comunicarse con este código para obtener todas las tareas que se están ejecutando en ese momento. Teniendo en cuenta que estoy usando una simple List<Tast> para guardar la referencia de todas las tareas, necesito una manera de bloquear la lsita para añadir elementos a la lista, enumerar la lista y eliminar elementos. Pero queiro que este bloqueo dure lo menos posible para hacer que mi aplicación se ejecute lo más rápido posible y además quiero solo bloquear para las operaciones importantes añadir y eliminar tareas

Así que tengo dos operaciones importantes, crear una nueva tarea y añadirla a la lista, y cuando la tarea termina eliminar esa tarea del servidor, pero tengo que tener en cuenta que múltiples tareas pueden estar ejecutándose a la misma vez.

La creación de tareas es responsabilidad de un temporizador que está configurado para ejecutarse para Segundo y si el número de tareas es menor que el número de tareas mínimas genera más tareas y cada tarea creada la añade al sistema. Teniendo en cuenta que este temporizador es ejecutado cada segundo, necesito bloquear mi lista, hacer mi trabajo y después desbloquear. Teniendo en cuenta que el bloqueo para acceder a la lista puede ser mayor que el tiempo del temporizador porque otros threads pueden estar usando la lista necesito establecer un tiempo máximo de bloqueo porque si no lo que conseguiré será una clásico convoy de bloqueos en mi aplicación.

Teniendo en cuenta esto dentro del método de mi temporizador utilizo la nueva API de Monitor.TryEnter de .NET 4 que intenta, para un número de milisegundos, adquirir el bloqueo exclusivo y atómicamente establecer un valor que indica si el bloqueo se ha obtenido o no. En mi caso he establecido el temporizador en 400ms, porque en mi método hago más cosas que trabajar con esa lista.

bool taken = false;
try
{
    Monitor.TryEnter(task, 400, ref taken);
    if (taken)
    {
        if (!cancelationTokenSource.IsCancellationRequested)
        {
            var count = (from p in task
                         where p.Status == TaskStatus.Running || p.Status == TaskStatus.WaitingToRun
                         select p).Count();

        }
    }
}
finally
{
    if (taken)
    {
        Monitor.Exit(task);
    }
}

Como se puede observar en el código estoy llamando a la función de Monitor.TryEnter dentro de un bloque de try/catch, y en el bloque de finllay si el bloqueo se ha adquirido lo libero llamando a la función Monitor.Exit. Lo hago de esta manera para asegurarme que si durante la ejecución de mi código se lanza una excepción el código de finally siempre será ejecutado y el bloqueo liberado. Si no lo hiciese de esta manera podría causar que se nunca se liberase el bloqueo y tener un deadlock.

El otro escenario donde trabajo con la lista es para obtener el número de tareas ejecutándose, y hago lo mismo dentro de accesor get de una propiedad, pero esta vez lo tengo configurado a 250ms. Si el bloqueo se adquiere satisfactoriamente, lo que hago es copiar la lista en una lista nueva par después de manera segura trabajar sobre esa nueva lista.

public List<Task> Tasks
{
    get
    {
        bool taken = false;
        List<Task> list = null;
        try
        {
            Monitor.TryEnter(task, 250, ref taken);
            if (taken)
            {
                list = new List<Task>(task.ToArray());
            }
        }
        finally
        {
            if (taken)
            {
                Monitor.Exit(task);                         
            }
        }
        return list;
    }
}

Esta solución es simple y mantiene tu código con la tasa de contención más baja posible, pues no esperas infinitamente en todos los casos, solo en los más importantes.

A parte de esto podría haber hecho un wrapper de List<T> con ReaderWriterLockSlim para controlar las operaciones de lectura y escritura durante el bloqueo, pero ReaderWriterLockSlim está pensado para trabajar con varios lectores y solo un escritor y en mi aplicación tengo múltiples escritores y solo un lector.

Saludos.

Luis.

Writing high performance parallel code with monitors [EN]

Multithread application is going to be next issue for developer, and we need to be ready for this big change. In .NET Framework 4, Microsoft introduced Task Parallel Library, a set of API that helps developer creating concurrent applications. That’s means that you don’t have to take care about all those concurrent issues anymore, its mean now is easier to create concurrent code.

Currently I’m working in an application that makes a hard use of all TLP code. What I do is creating a lot of Task objects to manage the executing of a set of rules that have to be executed for each Uri. I maintain a list with all the Task object to observer during time, how much Task are now running, and make some statistics about software speed.

This means I have UI, created in WPF that need to communicate with this code to get all running Task and display this information in the UI. Since I’m using a simple List<Task> to get a reference to all task created during my application execution, I need a way to lock and add Tasks to this list, enumerate this list and remove Tasks. But I want this lock to be shortest one and only lock to important operations like add and remove items when Task are finished.

So I have two important operations, create new Task and add to this list, and when the Task is finish removes this Task from the list, and for that I need to wait if the lock is acquired by other thread, because multiple Tasks can finish at the same time.

Creating task is done by a timer inside my application and this timer is set to run each second to check if the running Task in the system are lower that minimum Task running. If this is true is the moment create more Task and add to the list. Since this timer is executed every second I’ll need to lock my list of Task, do my work and then release the lock. I’m using the list as lock object. But this timer can wait more than one second until the lock is released, because other Task are now executing and finish work and remove items from my list, so It’s mean I’m creating a classic convoy in my application. Every time my timer method is executed and wait until the lock to release, this time is bigger that timer elapsed time, so I need a way to wait only a certain period of time.

What I do in this method is using the new API for Monitor in .NET 4 that attempts, for a number of milliseconds, to acquire an exclusive lock and atomically set a value that indicates whether the lock was taken or not. In my case I set these milliseconds in 400, because in this method I do more stuff than work with my list of Task. If the lock is bigger than 400ms the lock will not be acquired.

bool taken = false;
try
{
    Monitor.TryEnter(task, 400, ref taken);
    if (taken)
    {
        if (!cancelationTokenSource.IsCancellationRequested)
        {
            var count = (from p in task
                         where p.Status == TaskStatus.Running || p.Status == TaskStatus.WaitingToRun
                         select p).Count();
        }
    }
}
finally
{
    if (taken)
    {
        Monitor.Exit(task);
    }
}

As you can see in this code I’m calling Monitor.TryEnter inside a try/catch block, and then in the finally block if the lock was acquired I release the lock by calling Monitor.Exit. I do in that way because if during the execution of my code an exception is throw, the call to Monitor.Exit at the end of the code will not be executed anymore, causing that I have a lock that will never be released.

My other scenario is when I want to get all Task to count how much task are now running, I do the same inside get accessor of the property Task, but in this case I only wait for 250ms instead of 400ms. If the lock is acquired I copy the collection into a new list and there I can safety count how much Task are running.

public List<Task> Tasks
{
    get
    {
        bool taken = false;
        List<Task> list = null;
        try
        {
            Monitor.TryEnter(task, 250, ref taken);
            if (taken)
            {
                list = new List<Task>(task.ToArray());
            }
        }
        finally
        {
            if (taken)
            {
                Monitor.Exit(task);                         
            }
        }
        return list;
    }
}

 

This solution is simple and keeps your code with the lowest contention rate giving boots to those important operations that need to wait until the lock is released.

I could also create a wrap over List<T> list using ReaderWriterLockSlim to control read and write operation during lock, but ReaderWriterLockSlim is focus on multiple readers and only one writer, and I my application I have multiple writers and only one reader.

All the best.

Luis.

Trabajando con Heap Corruptions in .NET

Una de las mejores características de .NET Framework es la administración automática de la memoria, eso significa que no tenemos que estar pendientes de memory leaks, corrupciones y demás problemas. Pero en este artículo encontraremos que esto no es así todas las veces. Os quiero mostrar un bug que he encontrado en una aplicación .NET 4.

Como ya sabreis el clr tiene una heap administrado que contiene todos los objetos que se han ido creando en todo el código ejecutado, y es precisamente en ese managed heap donde el recolector de basura trabaja para ordenarlo y limpiarlo. Vamos a utilizar algunos comandos de WinDBG para ver el estado del heap

Durante la ejecución de mi aplicación aleatoriamente la aplicación me lanza un System.ExecutionEngineException. Como se puede imaginar esta excepción es fatal y no hay oportunidad para cachearla así que mi aplicación se cierra cuando se encuentra con una excepción como esta.

 

0:281> !threads
ThreadCount:      325
UnstartedThread:  0
BackgroundThread: 268
PendingThread:    0
DeadThread:       56
Hosted Runtime:   no
                                           PreEmptive                                                   Lock
       ID  OSID        ThreadOBJ     State GC       GC Alloc Context                  Domain           Count APT Exception
   0    1   f74 00000000001b47b0      6020 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 STA
   2    2  3ddc 00000000001baaf0      b220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Finalizer)
   5    3  3f44 0000000000fb8ee0   100a220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
   7    4  2acc 000000001c75c120   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
   8    5   f2c 000000001c75c830   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
   9    6  1bf4 000000001c75cf40   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  10    7  1e10 000000001c75ea80   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
XXXX    9       000000001c7f8dd0   1019820 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  12    b  1a9c 000000001c814830   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  13    d  1f50 000000001df31e80   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  14    a  21b4 000000001c7fdd10   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  15    f  2d54 000000001df31160   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  18   10  3edc 000000001df4ef50      b220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     1 MTA
  19   12  3ffc 000000001df60bd0   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  20    e   958 000000001df612e0   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  21    c  2be0 000000001df62100   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  22   14  1920 000000001df62f20   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  23   11  39f0 000000001df619f0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  24   15  2e00 000000001df63630   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
XXXX   16       000000001df63d40   1019820 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  25   17   734 000000001df64450   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  26   18  2c78 000000001df64b60   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
XXXX   19       000000001df65270   1019820 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 Ukn (Threadpool Worker)
  27   1a  2330 000000001df62810   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  28   1c  20f4 000000001df667a0   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
XXXX   13       000000001df66090   1019820 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
XXXX   1e       000000001df675c0   1019820 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  29   1b  360c 000000001df66eb0   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  30   1d  1f04 000000001df67cd0   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  31    8   ce0 000000001df65980   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  32   20  3a94 000000001df34070   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  33   21  2ce8 000000001df34780   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  34   22  3dd4 000000001df355a0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  35   24  31c8 000000001df363c0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  36   26  15d0 000000001df371e0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  37   23  3aec 000000001df35cb0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  38   27  33b8 000000001df378f0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  39   1f   afc 000000001df34e90   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  40   28   9b8 000000001df683e0   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  41   29  1ba8 000000001c81e7c0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
XXXX   2a       000000001c81f5e0   1019820 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  42   25  3cbc 000000001c81eed0   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  43   2c  20fc 000000001df36ad0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  44   2d  290c 000000001c8573d0   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (GC) (Threadpool Worker) System.ExecutionEngineException (0000000002871228)
  45   2b  2f58 000000001c81fcf0   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  46   2f  33b4 000000001c8581f0   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
XXXX   2e       000000001c858900   1019820 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 Ukn (Threadpool Worker)
  47   31  1020 000000001c859010   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
XXXX   32       000000001c859720   1019820 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 Ukn (Threadpool Worker)
  48   33   ad8 000000001c859e30   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  49   34  3230 000000001c85a540   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  50   35  1a74 000000001c85ac50   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  51   36  3650 000000001c8064f0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  52   37  2890 000000001c806c00   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
XXXX   38       000000001c807310   1019820 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  53   39  1c20 000000001c807a20   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
XXXX   3a       000000001dfe2860   1019820 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  54   3b  1694 000000001dfe2f70   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  55   3d  37b8 000000001dfe3d90   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
XXXX   30       000000001dfe44a0   1019820 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
XXXX   3e       000000001dfe4bb0   1019820 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  56   3f  18b8 000000001dfe52c0   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  57   40  11b0 000000001dfe59d0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  58   41  1ee0 000000001dfe60e0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
XXXX   42       000000001c857ae0   1019820 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  59   43  27e8 000000001e0c80b0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  60   44   a84 000000001e0c87c0   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  61   46  1ba4 000000001e0c95e0   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  62   48  2160 000000001e0ca400   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  63   4a  2bdc 000000001e0cb220   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  64   47  12d0 000000001e0c9cf0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  65   49   be4 000000001e0cab10   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  66   3c  186c 000000001e0cb930   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
XXXX   4b       000000001dfe3680   1019820 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  67   45  3498 000000001e0c8ed0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
XXXX   4d       000000001e19b9a0   1019820 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  68   4e  1550 000000001e19c0b0   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  69   50  313c 000000001e19ced0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
XXXX   51       000000001e19d5e0   1019820 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
XXXX   4f       000000001e19c7c0   1019820 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  70   52  20bc 000000001e19dcf0   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  71   4c  33fc 000000001e19b290   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  72   54  2380 000000001e19eb10   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  73   53   a04 000000001e19e400   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  74   56  2028 000000001e22f050   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  75   58  3df0 000000001e22fe70   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
XXXX   57       000000001e230580   1019820 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  76   55  1d08 000000001e22f760   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
XXXX   5a       000000001e230c90   1019820 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  77   5c  373c 000000001e231ab0   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
XXXX   59       000000001e22e940   1019820 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 Ukn (Threadpool Worker)
  78   5d   e90 000000001e2321c0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
XXXX   5e       000000001e2ba200   1019820 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  79   5f  1358 000000001e2ba910   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
XXXX   5b       000000001e2bb020   1019820 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  80   60  1a98 000000001e2bb730   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  81   61  26f4 000000001e2bbe40   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  82   62   abc 000000001e2bc550   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  83   63  19d4 000000001e2bcc60   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  84   64  1220 000000001e2bd370   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  85   65  1e6c 000000001e2bda80   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  86   66  162c 000000001e2313a0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
XXXX   67       000000001e2de370   1019820 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  87   68  3040 000000001e2dea80   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  88   6a  139c 000000001e2df8a0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  89   6b  39f4 000000001e2dffb0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  90   6c  375c 000000001e2e06c0   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  91   6d  1548 000000001e2e0dd0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  92   6e  2920 000000001e2e14e0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
XXXX   6f       000000001e2e1bf0   1019820 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  93   70  376c 000000001e2e6370   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
XXXX   71       000000001e2e6a80   1019820 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  94   72  14ec 000000001e2e7190   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
XXXX   75       000000001e2e78a0   1019820 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  95   73  1930 000000001e2e86c0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  96   76  17dc 000000001e2e8dd0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  97   74   c88 000000001e2e7fb0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  98   77   d0c 000000001e2e94e0   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
XXXX   78       000000001e2e9bf0   1019820 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
XXXX   7a       0000000024ddd4c0   1019820 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
  99   7b  2878 0000000024dddbd0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 100   79  1278 0000000024dde2e0   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 101   7c  2358 0000000024ddcdb0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
XXXX   7d       0000000024dde9f0   1019820 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 102   7e  28a8 0000000024ddf100   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 103   7f  1778 0000000024ddf810   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 104   80  2990 0000000024ddff20   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 105   81  1864 0000000024de0630   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 106   82  3dc4 0000000024de4db0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 107   83  371c 0000000024de54c0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 108   84  3e80 0000000024de5bd0   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 109   85  3634 0000000024de62e0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 110   86  3908 0000000024de69f0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 111   87  2998 0000000024de7100   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 112   88  200c 0000000024de7810   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 113   89  3370 0000000024de7f20   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 114   8a  33dc 0000000024de8630   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 115   8b  1b98 0000000024df2a90   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 116   8c  1378 0000000024df31a0   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 117   8d  3e0c 0000000024df38b0   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
XXXX   8e       0000000024df3fc0   1019820 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 118   8f  3444 0000000024df46d0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 119   90  3044 0000000024df4de0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
XXXX   91       0000000024df54f0   1019820 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 120   92  389c 0000000024df5c00   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 121   93  3938 0000000024df6310   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
XXXX   95       0000000024e8d5b0   1019820 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 122   96  18e0 0000000024e8dcc0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 123   97  3954 0000000024e8cea0   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 124   98  329c 0000000024e8e3d0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 125   94  2cf0 0000000024e8eae0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 126   9a  3d18 0000000024e8f900   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 127   9b   a80 0000000024e8f1f0   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 128   9c  13ac 0000000024e90720   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 129   99  2f84 0000000024e90010   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
XXXX   9e       000000001e0f9180   1019820 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
XXXX   9f       000000001e0f8a70   1019820 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 130   a0  2a20 000000001e0f9fa0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
XXXX   9d       000000001e0f9890   1019820 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 131   a3  2544 000000001e0fb4d0   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 132   a1  2910 000000001e0fa6b0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 133   a4   a9c 000000001e0fadc0   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 134   a5  1880 000000001e0fbbe0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 135   a6  2d28 0000000024f038f0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 136   a7  12d4 0000000024f04710   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
XXXX   a8       0000000024f04e20   1019820 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 137   a9  11c8 0000000024f05530   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 138   ab  2d4c 0000000024f06350   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 139   aa  1bf8 0000000024f05c40   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 140   a2   244 0000000024f04000   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 141   ac  2688 0000000024f06a60   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 142   ad  27e0 0000000024f07170   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 143   ae  315c 000000001e0fc2f0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
XXXX   af       000000002501d670   1019820 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 144   b0   7bc 000000002501dd80   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 145   b3  1294 000000002501f2b0   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 146   b4  3e94 000000002501f9c0   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 147   b5   fc8 00000000250200d0   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 148   b6   d48 00000000250207e0   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 149   b7  1f84 0000000025020ef0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 150   b8  3138 0000000025021600   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 151   b9  3214 0000000025021d10   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 152   ba  175c 0000000025022420   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 153   bb  3a24 0000000025022b30   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 154   bc  340c 0000000025023240   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
XXXX   bd       0000000025023950   1019820 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 155   be  27b4 0000000025024060   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 156   bf  2c54 0000000025024770   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 157   c0  3698 0000000025024e80   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 158   c1  20f0 0000000025064a30   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 159   c2   1dc 0000000025065140   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 160   c3  2378 0000000025065850   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 161   c4  1444 0000000025065f60   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
XXXX   c5       0000000025066670   1019820 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
XXXX   c6       0000000025066d80   1019820 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 162   c7   b0c 0000000025067490   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 163   c8  30f4 0000000025067ba0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 164   c9  3d60 00000000250682b0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 165   ca  108c 00000000250689c0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 166   cb  37b0 00000000250690d0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
XXXX   cc       00000000250697e0   1019820 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 167   b1   dc0 0000000025069ef0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 168   b2  3ed4 000000002506a600   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
XXXX   cd       000000002506ad10   1019820 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 169   ce   c38 000000002506b420   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 170   cf  24cc 000000002506bb30   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
XXXX   d0       000000002506c240   1019820 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 171   d1  1d80 000000002501e490   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 172   d2  1edc 000000002501eba0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 173   d3  304c 000000002513cbf0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 174   d4  3b08 000000002513d300   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 175   d7  3adc 000000002513e830   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
XXXX   d8       000000002513ef40   1019820 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 177   69  2178 000000002513da10   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 178   d6  3b40 000000002513e120   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 179   d9   f28 000000002513fd60   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 180   da  382c 0000000025140470   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
XXXX   db       0000000025140b80   1019820 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 181   dc   b88 0000000025141290   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 182   dd  22ac 00000000251419a0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 183   df  1aac 00000000251427c0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 184   e0  353c 0000000025142ed0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
XXXX   d5       000000002513f650   1019820 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 185   de  319c 00000000251420b0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
XXXX   e1       00000000251435e0   1019820 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 186   e2  3678 0000000025143cf0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 187   e3  13fc 0000000025144400   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 188   e4  3038 000000001e2df190   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 189   e5  3cc0 0000000024e5ae20   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 190   e6  3384 0000000024e5b530   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 191   e7  301c 0000000024e5bc40   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 192   e8  3448 0000000024e5c350   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 193   e9  2bcc 0000000024e5ca60   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
XXXX   ea       0000000024e5d170   1019820 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
XXXX   eb       0000000024e5d880   1019820 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
XXXX   ec       0000000024e5df90   1019820 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 194   ed  1d04 0000000024e5e6a0   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 195   ee   c54 000000002523fed0   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 196   ef  2220 00000000252405e0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 197   f0  2b60 0000000025240cf0   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 198   f1  2d88 0000000025241400   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 199   f2  3ee8 0000000025241b10   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 200   f3  3f2c 0000000025242220   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 201   f4  1240 0000000025242930   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 202   f6  23dc 0000000025243750   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 203   f7   a74 0000000025243040   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 204   f8  3f40 0000000025243e60   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 205   f9  2f94 0000000025244c80   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 206   fa   fa4 0000000025245390   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 207   fb  2c7c 0000000025245aa0   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 208   f5  2a30 0000000025244570   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 209   fe  102c 0000000025246fd0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
XXXX  100       0000000025384550   1019820 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 210   fd   c28 00000000252461b0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 211   ff  233c 0000000025384c60   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 212  101  3c34 00000000252476e0   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
XXXX  102       0000000025385a80   1019820 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 213  104  1ad4 00000000253868a0   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 214   fc  2ef0 0000000025385370   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 215  103  16bc 0000000025386190   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 216  105   990 0000000025386fb0   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 218  107  3b38 0000000025387dd0   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 219  108   974 00000000253884e0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 220  109  10e4 0000000025388bf0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 221  10a  1280 0000000025389300   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 222  10b  1494 00000000253876c0   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 223  106  25ac 0000000025389a10   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 224  10e  2b94 000000002538af40   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 225  10c  3218 000000002538a830   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 226  110  2a5c 000000002538bd60   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 227  10d  2d90 000000002538b650   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 228  10f   e10 00000000252468c0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 229  112  21bc 0000000025464400   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 230  113  13e4 0000000025464b10   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 231  114  2d84 0000000025465220   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 232  115  3e98 0000000025465930   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 233  116  115c 0000000025466040   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 234  117  1228 0000000025466750   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
XXXX  118       0000000025466e60   1019820 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 235  119  3054 0000000025467570   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 236  11a  10f4 0000000025467c80   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 237  11b  18b4 0000000025468390   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 238  11c  3a1c 0000000025468aa0   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 239  11d  187c 00000000254691b0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 240  11e  342c 00000000254698c0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 241  11f  12f4 0000000025469fd0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 242  120  2a04 000000002546a6e0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 243  121  36dc 000000002546adf0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 244  122   ffc 000000002546b500   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 245  123   c70 000000002546bc10   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 246  124  39f8 000000002546c400   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 247  125  34c4 000000002546cb10   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
XXXX  126       000000002546d220   1019820 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 248  127   ae0 000000002546d930   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 249  129  17fc 000000002546ee60   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 250  12b  2288 000000002546f570   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 251  111  2fa0 000000002546e750   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
XXXX  12a       000000002546fc80   1019820 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 252  128  3160 0000000025470aa0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 253  12c  1fd8 000000002546e040   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 256  12d  13bc 0000000025472df0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 258  12e   fc0 00000000254718c0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 259  12f  2d34 0000000025471fd0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 260  130  366c 00000000254726e0   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 261  131   af0 00000000254711b0   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 262  132  2bbc 0000000025470390   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 263  133   ae8 0000000025473500   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 264  134  37b4 0000000025473c10   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 265  135  1e54 000000002538a120   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 266  136  3fa0 0000000033dbb290   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 267  137  2698 0000000033dbb9a0   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 268  138   ec0 0000000033dbc0b0   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 269  139   d30 0000000033dbc7c0   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 270  13a   cc8 0000000033dbced0   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 271  13b  29f4 0000000033dbd5e0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 272  13c  2c74 0000000033dbdcf0   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 273  13d  3150 0000000033dbe400   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 274  13e  27c4 0000000033dbeb10   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 275  13f  1ee8 0000000033dbf220   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 276  140  1dec 0000000033dbf930   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 277  141  3398 0000000033dc0040   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 278  14a  274c 0000000033e073f0   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 279  14b  1d50 0000000033e08210   3009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
 280  149  1258 0000000033e07b00   1009220 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 MTA (Threadpool Worker)
XXXX  148       0000000033e06ce0     19820 Enabled  0000000000000000:0000000000000000 00000000001a85b0     0 Ukn

Como vemos en esta salida de WinDBG tenemos varios thread y en el thread 44 hay una excepción (GC) (Threadpool Worker) System.ExecutionEngineException (0000000002871228) y esta dirección es la dirección de memoria donde es el System.ExecutionEngineException. Empecemos la investigación desde ahí.

0:281> !pe 0000000002871228
Exception object: 0000000002871228
Exception type:   System.ExecutionEngineException
Message:          <none>
InnerException:   <none>
StackTrace (generated):
<none>
StackTraceString: <none>
HResult: 80131506
The current thread is unmanaged

 

 

Ahora como siempre examinemos las pilas nativas y administrada.

0:044> !clrstack
OS Thread Id: 0x290c (44)
Child SP         IP               Call Site
000000002191d9b8 000007fef3fecca3 [HelperMethodFrame: 000000002191d9b8] 
000000002191dc30 000007fef2f394b7 System.Text.StringBuilder.ToString()
000000002191dc80 000007feed584193 System.Data.Query.PlanCompiler.CTreeGenerator.ResolveVar(System.Data.Query.InternalTrees.Var)
000000002191dd40 000007feed5845fe System.Data.Query.PlanCompiler.CTreeGenerator.CreateProject(RelOpInfo, System.Collections.Generic.IEnumerable`1<System.Data.Query.InternalTrees.Var>)
000000002191de10 000007feed587e49 System.Data.Query.PlanCompiler.CTreeGenerator.Visit(System.Data.Query.InternalTrees.PhysicalProjectOp, System.Data.Query.InternalTrees.Node)
000000002191deb0 000007feed58582c System.Data.Query.PlanCompiler.CTreeGenerator..ctor(System.Data.Query.InternalTrees.Command, System.Data.Query.InternalTrees.Node)
000000002191df10 000007feed5725f1 System.Data.Query.PlanCompiler.ProviderCommandInfoUtils.Create(System.Data.Query.InternalTrees.Command, System.Data.Query.InternalTrees.Node, System.Collections.Generic.List`1<System.Data.Query.PlanCompiler.ProviderCommandInfo>)
000000002191df60 000007feed536485 System.Data.Query.PlanCompiler.CodeGen.Process(System.Collections.Generic.List`1<System.Data.Query.PlanCompiler.ProviderCommandInfo> ByRef, System.Data.Query.InternalTrees.ColumnMap ByRef, Int32 ByRef)
000000002191dfe0 000007feed4b4d90 System.Data.Query.PlanCompiler.PlanCompiler.Compile(System.Collections.Generic.List`1<System.Data.Query.PlanCompiler.ProviderCommandInfo> ByRef, System.Data.Query.InternalTrees.ColumnMap ByRef, Int32 ByRef, System.Data.Common.Utils.Set`1<System.Data.Metadata.Edm.EntitySet> ByRef)
000000002191e0d0 000007feed54418e System.Data.EntityClient.EntityCommandDefinition..ctor(System.Data.Common.DbProviderFactory, System.Data.Common.CommandTrees.DbCommandTree)
000000002191e270 000007feed62aae4 System.Data.EntityClient.EntityProviderServices.CreateDbCommandDefinition(System.Data.Common.DbProviderManifest, System.Data.Common.CommandTrees.DbCommandTree)
000000002191e2b0 000007feed5cf34d System.Data.Objects.Internal.ObjectQueryExecutionPlan.Prepare(System.Data.Objects.ObjectContext, System.Data.Common.CommandTrees.DbQueryCommandTree, System.Type, System.Data.Objects.MergeOption, System.Data.Objects.Span, System.Collections.ObjectModel.ReadOnlyCollection`1<System.Collections.Generic.KeyValuePair`2<System.Data.Objects.ObjectParameter,System.Data.Objects.ELinq.QueryParameterExpression>>)
000000002191e3b0 000007feed5fec9a System.Data.Objects.ELinq.ELinqQueryState.GetExecutionPlan(System.Nullable`1<System.Data.Objects.MergeOption>)
000000002191e4b0 000007feed610a65 System.Data.Objects.ObjectQuery`1[[System.__Canon, mscorlib]].GetResults(System.Nullable`1<System.Data.Objects.MergeOption>)
000000002191e530 000007feed6117cf System.Data.Objects.ObjectQuery`1[[System.__Canon, mscorlib]].System.Collections.Generic.IEnumerable<T>.GetEnumerator()
000000002191e580 000007feef066e79 System.Linq.Enumerable.First[[System.__Canon, mscorlib]](System.Collections.Generic.IEnumerable`1<System.__Canon>)
000000002191e5e0 000007feef081daf System.Linq.Queryable.First[[System.__Canon, mscorlib]](System.Linq.IQueryable`1<System.__Canon>)
000000002191e640 000007ff00416efa ServerDetection.Data.DataAccess.UpdateSever(ServerDetection.Server)
000000002191e940 000007ff004133b6 ServerDetection.StreamRulesEngine.ExploreServer(ServerDetection.Server)
000000002191eb50 000007ff00412f2c ServerDetection.StreamRulesEngine.<CreateTask>b__15(System.Object)
000000002191eb90 000007fef36796bb System.Threading.Tasks.Task.Execute()
000000002191ebf0 000007fef2f60d3c System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object, Boolean)
000000002191ec50 000007fef3679455 System.Threading.Tasks.Task.ExecuteWithThreadLocal(System.Threading.Tasks.Task ByRef)
000000002191ecd0 000007fef367d9d0 System.Threading.Tasks.Task.ExecuteEntry(Boolean)
000000002191ed10 000007fef2f96be8 System.Threading.ThreadPoolWorkQueue.Dispatch()
000000002191eda0 000007fef2f96a85 System.Threading._ThreadPoolWaitCallback.PerformWaitCallback()
000000002191f3f0 000007fef3e621b4 [DebuggerU2MCatchHandlerFrame: 000000002191f3f0] 
0:044> kb 2000
RetAddr           : Args to Child                                                           : Call Site
000007fe`f3feaf0a : 00000000`00000001 00000000`00000000 000007fe`00000002 000007fe`00000001 : clr!WKS::gc_heap::plan_phase+0x454
000007fe`f3feb6a5 : 000000d4`19ef3257 00000000`2191d629 00000000`00000001 00000000`00000001 : clr!WKS::gc_heap::gc1+0xbb
000007fe`f3feb35e : 00000000`00193900 000007fe`00000000 00000000`00000000 00000000`00000000 : clr!WKS::gc_heap::garbage_collect+0x276
000007fe`f3fe9c18 : 00000000`1c857440 00000000`00000088 000007fe`f3e30000 00000000`09350d00 : clr!WKS::GCHeap::GarbageCollectGeneration+0x14e
000007fe`f3fe929e : 00000000`000000a8 000007fe`f46c3700 00000000`2191d800 00000000`1c857440 : clr!WKS::gc_heap::try_allocate_more_space+0x25f
000007fe`f3ee4a95 : 00000000`00000088 00000000`00193900 00000000`1c857440 00000000`2191dca0 : clr!WKS::GCHeap::Alloc+0x7e
000007fe`f2f394b7 : 00000000`08000001 00000000`09351c00 00000000`030d39f0 00000000`0934f478 : clr!FramedAllocateString+0xb19
000007fe`ed584193 : 00000000`09350e88 00000000`09350d00 00000000`0300b1a8 00000000`09350e88 : mscorlib_ni+0x3694b7
000007fe`ed5845fe : 00000000`09350e08 00000000`093405d0 00000000`000000fa 00000000`00000000 : System_Data_Entity_ni+0x854193
000007fe`ed587e49 : 00000000`0934f478 00000000`09350ce8 00000000`00000000 000007fe`f3e98733 : System_Data_Entity_ni+0x8545fe
000007fe`ed58582c : 00000000`0934f478 00000000`0934bff0 00000000`093382d8 000007fe`ed5734c8 : System_Data_Entity_ni+0x857e49
000007fe`ed5725f1 : 00000000`2191def0 000007fe`f3e701ff 00000000`00000000 00000000`2191e1c8 : System_Data_Entity_ni+0x85582c
000007fe`ed536485 : 00000000`09334420 000007fe`ed3ed8b9 00000000`0934f450 00000000`2191e050 : System_Data_Entity_ni+0x8425f1
000007fe`ed4b4d90 : 00000000`00000000 00000000`00000000 00000000`02de9628 00000000`1288f490 : System_Data_Entity_ni+0x806485
000007fe`ed54418e : 00000000`00000000 00000000`00000000 00000000`00000000 00000000`00000000 : System_Data_Entity_ni+0x784d90
000007fe`ed62aae4 : 00000000`093341a0 00000000`062e3608 00000000`09333ef8 00000000`09333ef8 : System_Data_Entity_ni+0x81418e
000007fe`ed5cf34d : 00000000`09333f28 000007fe`ed3f0a59 00000000`04f1db88 000007fe`f2f46f83 : System_Data_Entity_ni+0x8faae4
000007fe`ed5fec9a : 00000000`062e3608 000007ff`003d27e8 00000000`02db2aa0 0000635b`00000000 : System_Data_Entity_ni+0x89f34d
000007fe`ed610a65 : 00000000`04f1db88 00000000`00000000 000007ff`002ae568 00000000`2191e0b8 : System_Data_Entity_ni+0x8cec9a
000007fe`ed6117cf : 00000000`04f1dbe8 000007ff`00489730 000007fe`eeefa86f 00000000`00000000 : System_Data_Entity_ni+0x8e0a65
000007fe`ef066e79 : 00000000`062e7bc8 00000000`090f7a68 00000000`090f7a68 000007fe`ed5ff21f : System_Data_Entity_ni+0x8e17cf
000007fe`ef081daf : 000007ff`00489730 000007ff`00489430 00000000`09124478 00000000`08ee3668 : System_Core_ni+0x456e79
000007ff`00416efa : 000007ff`00488e40 00000000`00000000 00000000`08ed3048 00000000`12871030 : System_Core_ni+0x471daf
000007ff`004133b6 : 00000000`02dc41e8 00000000`0603a228 00000000`033d1008 000007fe`f383ea3c : 0x7ff`00416efa
000007ff`00412f2c : 00000000`02db1118 00000000`0603a228 00000000`2191ec88 000007fe`f3e7063c : 0x7ff`004133b6
000007fe`f36796bb : 00000000`02db1118 00000000`0603a228 00000000`0603a3a8 000007fe`f2f61545 : 0x7ff`00412f2c
000007fe`f2f60d3c : 00000000`0603a3a8 00000000`1c8573d8 00000000`2191ec40 000007fe`f3e6ed1e : mscorlib_ni+0xaa96bb
000007fe`f3679455 : 00000000`12871030 00000000`0603a3a8 00000000`2191ec88 00000000`00000001 : mscorlib_ni+0x390d3c
000007fe`f367d9d0 : 00000000`0603a3a8 00000000`033d1018 00000000`0603a3a8 000007fe`f2fe71a9 : mscorlib_ni+0xaa9455
000007fe`f2f96be8 : 000007fe`f2c4e7f8 00000000`2191f140 000007ff`00022020 00000000`0316bf48 : mscorlib_ni+0xaad9d0
000007fe`f2f96a85 : 48cc31a4`460aef00 00000000`09103290 00000000`00000000 00000004`00000005 : mscorlib_ni+0x3c6be8
000007fe`f3e621b4 : 48cc31a4`460aef03 000007fe`f2f66e32 00000000`09103200 00000001`000001bb : mscorlib_ni+0x3c6a85
000007fe`f3e67129 : 00000000`2191f208 00000000`02db11e0 00000000`21910000 00000000`00000000 : clr!CallDescrWorker+0x84
000007fe`f3e671a3 : 00000000`2191ef48 00000000`00000000 00000000`2191ef50 00000000`00000000 : clr!CallDescrWorkerWithHandler+0xa9
000007fe`f3e6c5b5 : 00000000`2191f6a8 00000000`2191f4c8 00000000`1c8573d0 00000000`00000001 : clr!MethodDesc::CallDescr+0x2f4
000007fe`f403c42f : 00000000`2191f6a8 00000000`2191f658 00000000`2191f4c8 00000000`00000000 : clr!MethodDescCallSite::CallWithValueTypes_RetArgSlot+0x35
000007fe`f3ef6c5a : ffffffff`fffffffe 000007fe`f3e33489 ffffffff`fffffffe 00000000`1c8573d0 : clr!QueueUserWorkItemManagedCallback+0x44
000007fe`f3ef6bef : 00000000`00000000 00000000`00000000 00000000`00000000 00000000`00000000 : clr!SystemDomain::LoadBaseSystemClasses+0x43e
000007fe`f3ef6b5c : 00000000`00159770 00000000`2191f380 00000000`00000000 00000000`2191f3c8 : clr!SString::Equals+0x190
000007fe`f403c2f9 : ffffffff`ffffffff 00000000`1c8573d0 00000000`00000000 000007fe`f3e333eb : clr!CParseUtils::TrimWhiteSpace+0x119
000007fe`f3f04bf5 : 00000000`00000c0a 00000000`00000000 00000000`1c8573d0 000007fe`f3ecd2d0 : clr!ManagedPerAppDomainTPCount::DispatchWorkItem+0xe6
000007fe`f4004377 : 00000000`00000000 00000000`1dfa6501 000000f2`00f200f2 00000000`00000c0a : clr!ThreadpoolMgr::NewWorkerThreadStart+0x49f
000007fe`f4002c22 : 00000000`00000000 00000000`00000000 00000000`2191f7a0 00000000`00000000 : clr!ThreadpoolMgr::WorkerThreadStart+0x3b
00000000`76e9f56d : 00000000`00000000 00000000`00000000 00000000`00000000 00000000`00000000 : clr!Thread::intermediateThreadProc+0x7d
00000000`770d3281 : 00000000`00000000 00000000`00000000 00000000`00000000 00000000`00000000 : kernel32!BaseThreadInitThunk+0xd
00000000`00000000 : 00000000`00000000 00000000`00000000 00000000`00000000 00000000`00000000 : ntdll!RtlUserThreadStart+0x1d

En mi pila administrada mi último frame es System.Text.StringBuilder.ToString(), así que asumimos que estamos creando memoria para ese string. Si miramos a la pila nativa observamos que justo en ese punto se estaba haciendo una recolección de basura.

La secuencia es: FramedAllocateString -> GCHeap::Alloc -> gc_heap::try_allocate_more_space -> GCHeap::GarbageCollectGeneration -> gc_heap::garbage_collect -> :gc_heap::gc1

Este punto estamos seguros de que realmente se estaba reservando memoria para ese string, pero como no habría más memoria disponible se había lanzado una recolección de basura y ahí es donde el runtime encontró la corrupción del heap.

Hay un commando muy util en WinDBG !verifyheap que nos permite comprobar que hay signos de corrupción en el heap adminsitrado.

 

0:044> !verifyheap
-verify will only produce output if there are errors in the heap
The garbage collector data structures are not in a valid state for traversal.
It is either in the "plan phase," where objects are being moved around, or
we are at the initialization or shutdown of the gc heap. Commands related to 
displaying, finding or traversing objects as well as gc heap segments may not 
work properly. !dumpheap and !verifyheap may incorrectly complain of heap 
consistency errors.
object 0000000006fb6ec8: bad member 0000000008f1b750 at 0000000006fb6ef8
curr_object:      0000000006fb6ec8
Last good object: 0000000006fb6e50
----------------

El commando !verifyheap nos está diciendo que en ese preciso momento se estaba realizando una recolección de basura que las estructuras del gc puede que no estén en un estado válido para que este comando extraiga toda la información, pero al final del reporte encontramos que hay un objeto que tiene un miembro inválido, este objeto es un System.IO.StreamReader y el miembro invalido es System.Char[] 0000000008f1b750 charBuffer.

0:044> !do 0000000006fb6ec8
<Note: this object has an invalid CLASS field>
Name:        System.IO.StreamReader
MethodTable: 000007fef30951a0
EEClass:     000007fef2cce0d0
Size:        96(0x60) bytes
File:        C:WindowsMicrosoft.NetassemblyGAC_64mscorlibv4.0_4.0.0.0__b77a5c561934e089mscorlib.dll
Fields:
              MT    Field   Offset                 Type VT     Attr            Value Name
000007fef30d9518  40001cd        8        System.Object  0 instance 0000000000000000 __identity
000007fef3091d08  4001fda      c80 System.IO.TextReader  0   shared           static Null
                                 >> Domain:Value  00000000001a85b0:NotInit  <<
000007fef30dd718  4001fde       54       System.Boolean  1 instance                1 _closable
000007fef30e3658  4001fdf       10     System.IO.Stream  0 instance 0000000006fb6e50 stream
000007fef30e3968  4001fe0       18 System.Text.Encoding  0 instance 00000000032d6848 encoding
000007fef30ac110  4001fe1       20  System.Text.Decoder  0 instance 0000000006fb6f28 decoder
000007fef30e0d00  4001fe2       28        System.Byte[]  0 instance 0000000008f1a738 byteBuffer
000007fef30db4a8  4001fe3       30        System.Char[]  0 instance 0000000008f1b750 charBuffer
000007fef30e0d00  4001fe4       38        System.Byte[]  0 instance 000000000287ff88 _preamble
000007fef30dc918  4001fe5       40         System.Int32  1 instance                0 charPos
000007fef30dc918  4001fe6       44         System.Int32  1 instance                0 charLen
000007fef30dc918  4001fe7       48         System.Int32  1 instance                0 byteLen
000007fef30dc918  4001fe8       4c         System.Int32  1 instance                0 bytePos
000007fef30dc918  4001fe9       50         System.Int32  1 instance             4096 _maxCharsPerBuffer
000007fef30dd718  4001fea       55       System.Boolean  1 instance                1 _detectEncoding
000007fef30dd718  4001feb       56       System.Boolean  1 instance                0 _checkPreamble
000007fef30dd718  4001fec       57       System.Boolean  1 instance                0 _isBlocked
000007fef30951a0  4001fdd      c88 ...m.IO.StreamReader  0   shared           static Null
                                 >> Domain:Value  00000000001a85b0:NotInit  <<

¿Qué podemos hacer con este problema?

Teniendo en cuenta que es un problema de corrupción en la pila lo que tenemos que hacer es simplemente llamar al servicio de soporte de Microsoft y notificarle lo que hemos encontrado.

Happy debugging. Luis.

Silverlight, un mejor manejo de los servicios

Como todos es sabido Silverlight trae soporte para invocar servicios web, tanto servicios web tradicionales de .net como servicios de WCF. En esto últimos solo con soporte para httpBasicBinding.

Cada vez que generamos un proxy en Visual Studio para un proyecto de Silverlight, el proxy generado solo soporta invocaciones asíncronas. No podemos de ninguna manera hacer una invocación síncrona a un servicio web y esperar a la respuesta. Puede haber muchas maneras por las cuales Microsoft implemento este comportamiento predeterminado, pero creo que el más importante de todos es hacer que la UI de las aplicaciones de Silverlight *nunca* dejen de responder.

Así que puestos en antecedentes, podemos ahora estudiar nuestro problema e intentar mitigarlo. Cuando generamos un proxy en Visual Studio, lo que obtenemos es una función con el mismo nombre que la operación del servicio + “Async” y un evento que es el nombre de la operación + “Completed” en la que en los argumentos de respuesta tenemos el resultado de la invocación del servicio.

Algo como esto:

public partial class TraditionalServices : UserControl
{
    private ServiceClient service;
    public TraditionalServices()
    {
        InitializeComponent();

        service = new ServiceClient();
        service.GetDateCompleted += new EventHandler<GetDateCompletedEventArgs>(OnGetDateCompleted);
        service.GetEmployeeCompleted += new EventHandler<GetEmployeeCompletedEventArgs>(OnGetEmployeeCompleted);


        Loaded += new RoutedEventHandler(OnLoaded);
    }

    void OnLoaded(object sender, RoutedEventArgs e)
    {
        service.GetDateAsync();
    }

    void OnGetEmployeeCompleted(object sender, GetEmployeeCompletedEventArgs e)
    {
        
    }

    void OnGetDateCompleted(object sender, GetDateCompletedEventArgs e)
    {
        
    }
}

Conforme uno empieza a trabajar con los servicios de Silverlight encuentra que el código se puede volver un poco complicado puesto que no podemos invocar al servicio y después trabajar directamente con el resultado sino que lo tenemos que hacer en el método que se llamará cuando se termine la invocación del servicio.

Lo que os propongo en este artículo es que construyáis una clase Helper que os ayude a lidiar con estos problemas y hacer así el código un poco más claro.

Del código anterior para realizar la invocación a un servicio pasamos a esta:

service.GetDateTime(value =>
{
    string currentDateTime = value.ToString();
});

Como se puede apreciar el resultado es mucho mejor que la manera tradicional de trabajar con los proxies además de que el código queda mucho más claro.

¿Cómo está este helper implementado?

La idea es usar expresiones Lambda para hacer el código más legible, lo único que necesitamos es un delegado de tipo Action<T> en el que T será del mismo tipo del resultado de nuestra invocación al servicio web. 

public void GetDateTime(Action<DateTime> value)
{
    service.GetDateAsync(value);
}

Con este simple patrón podemos simplificar las llamadas al servicio web y esconder su complejidad. 

public partial class MainPage : UserControl
{
Helpers.ServiceHelper service;
public MainPage()
{
   InitializeComponent();

   service = Helpers.ServiceHelper.Instance;


   service.GetDateTime(value =>
   {
       string currentDateTime = value.ToString();
   });


   service.GetEmployee(value =>
   {
       ListBox listbox = new ListBox();
       listbox.ItemsSource = value;
       LayoutRoot.Children.Add(listbox);
   });

   service.DoStuff(() =>
   {
       // do stuff done
   });
}
}

Lo que hace la clase Helper es, cada vez que se realiza una invocación del servicio web se pasa por parámetro una referencia del delegado de tipo Action<T> que contiene la función que se llamará cuando termine la invocación. Una vez que termina la invocación del servicio lo que hacemos es obtener ese valor de vuelta y invocar al delegado con el resultado que es del mismo tipo que la signatura del delegado Action<T>.

public class ServiceHelper
{
private static ServiceHelper instance = new ServiceHelper();
public static ServiceHelper Instance { get { return instance; } }

private ServiceClient service;

private ServiceHelper()
{
   service = new ServiceClient();
   service.GetDateCompleted += new EventHandler<GetDateCompletedEventArgs>(OnGetDateCompleted);
   service.GetEmployeeCompleted += new EventHandler<GetEmployeeCompletedEventArgs>(OnGetEmployeeCompleted);
   service.AddCompleted += new EventHandler<AddCompletedEventArgs>(OnAddCompleted);
   service.DoStuffCompleted += new EventHandler<System.ComponentModel.AsyncCompletedEventArgs>(OnDoStuffCompleted);
}

void OnDoStuffCompleted(object sender, System.ComponentModel.AsyncCompletedEventArgs e)
{
   if (e.Error == null)
   {
       Action action = (Action)e.UserState;
       action();
   }
}

void OnAddCompleted(object sender, AddCompletedEventArgs e)
{
   if (e.Error == null)
   {
       Action<int> action = (Action<int>)e.UserState;
       action(e.Result);
   }
}

void OnGetEmployeeCompleted(object sender, GetEmployeeCompletedEventArgs e)
{
   if (e.Error == null)
   {
       Action<ObservableCollection<Employee>> action = (Action<ObservableCollection<Employee>>)e.UserState;
       action(e.Result);
   }
}

void OnGetDateCompleted(object sender, GetDateCompletedEventArgs e)
{
   if (e.Error == null)
   {
       Action<DateTime> action = (Action<DateTime>)e.UserState;
       action(e.Result);
   }
}

public void GetDateTime(Action<DateTime> value)
{
   service.GetDateAsync(value);
}

public void GetEmployee(Action<ObservableCollection<Employee>> value)
{
   service.GetEmployeeAsync(value);
}

public void Add(AddArguments args, Action<int> value)
{
   service.AddAsync(args.Operand1, args.Operand2, value);
}

public void DoStuff(Action value)
{
   service.DoStuffAsync(value);
}

public class AddArguments
{
   public int Operand1 { get; set; }
   public int Operand2 { get; set; }
}
}

Os podeis descargar de aquí el ejemplo completo. http://www.luisguerrero.net/downloads/servicehelper.zip

Saludos. Luis.