"sys.monitoring" --- Execution event monitoring
***********************************************

Added in version 3.12.

======================================================================

Nota:

  "sys.monitoring" is a namespace within the "sys" module, not an
  independent module, so there is no need to "import sys.monitoring",
  simply "import sys" and then use "sys.monitoring".

Este espacio de nombres proporciona acceso a las funciones y
constantes necesarias para activar y controlar el monitoreo de
eventos.

As programs execute, events occur that might be of interest to tools
that monitor execution. The "sys.monitoring" namespace provides means
to receive callbacks when events of interest occur.

La API de monitoreo consta de tres componentes:

* Tool identifiers

* Events

* Callbacks


Identificadores de herramientas
===============================

A tool identifier is an integer and the associated name. Tool
identifiers are used to discourage tools from interfering with each
other and to allow multiple tools to operate at the same time.
Currently tools are completely independent and cannot be used to
monitor each other. This restriction may be lifted in the future.

Before registering or activating events, a tool should choose an
identifier. Identifiers are integers in the range 0 to 5 inclusive.


Registro y uso de herramientas
------------------------------

sys.monitoring.use_tool_id(tool_id: int, name: str, /) -> None

   Must be called before *tool_id* can be used. *tool_id* must be in
   the range 0 to 5 inclusive. Raises a "ValueError" if *tool_id* is
   in use.

sys.monitoring.clear_tool_id(tool_id: int, /) -> None

   Unregister all events and callback functions associated with
   *tool_id*.

sys.monitoring.free_tool_id(tool_id: int, /) -> None

   Should be called once a tool no longer requires *tool_id*. Will
   call "clear_tool_id()" before releasing *tool_id*.

sys.monitoring.get_tool(tool_id: int, /) -> str | None

   Returns the name of the tool if *tool_id* is in use, otherwise it
   returns "None". *tool_id* must be in the range 0 to 5 inclusive.

La máquina virtual trata todos los ID de la misma manera con respecto
a los eventos, pero los siguientes ID están predefinidos para
facilitar la cooperación de las herramientas:

   sys.monitoring.DEBUGGER_ID = 0
   sys.monitoring.COVERAGE_ID = 1
   sys.monitoring.PROFILER_ID = 2
   sys.monitoring.OPTIMIZER_ID = 5


Eventos
=======

Son aceptados los siguientes eventos:

sys.monitoring.events.BRANCH

   Una rama condicional es aceptada (o no).

sys.monitoring.events.CALL

   Una llamada en código Python (el evento ocurre antes de la
   llamada).

sys.monitoring.events.C_RAISE

   An exception raised from any callable, except for Python functions
   (event occurs after the exit).

sys.monitoring.events.C_RETURN

   Return from any callable, except for Python functions (event occurs
   after the return).

sys.monitoring.events.EXCEPTION_HANDLED

   Se maneja una excepción.

sys.monitoring.events.INSTRUCTION

   Está a punto de ejecutarse una instrucción de VM.

sys.monitoring.events.JUMP

   Se realiza un salto incondicional en el gráfico de flujo de
   control.

sys.monitoring.events.LINE

   Está a punto de ejecutarse una instrucción que tiene un número de
   línea diferente al de la instrucción anterior.

sys.monitoring.events.PY_RESUME

   Resumption of a Python function (for generator and coroutine
   functions), except for "throw()" calls.

sys.monitoring.events.PY_RETURN

   Retorna de una función Python (ocurre inmediatamente antes del
   retorno, el marco del destinatario estará en la pila).

sys.monitoring.events.PY_START

   Inicio de una función Python (ocurre inmediatamente después de la
   llamada, el marco del destinatario estará en la pila)

sys.monitoring.events.PY_THROW

   A Python function is resumed by a "throw()" call.

sys.monitoring.events.PY_UNWIND

   Salida de una función Python durante la resolución de excepciones.

sys.monitoring.events.PY_YIELD

   Rinde (*yield*) desde una función Python (ocurre inmediatamente
   antes del rendimiento, el marco del destinatario estará en la
   pila).

sys.monitoring.events.RAISE

   An exception is raised, except those that cause a "STOP_ITERATION"
   event.

sys.monitoring.events.RERAISE

   An exception is re-raised, for example at the end of a "finally"
   block.

sys.monitoring.events.STOP_ITERATION

   An artificial "StopIteration" is raised; see the STOP_ITERATION
   event.

Es posible que se agreguen más eventos en el futuro.

These events are attributes of the "sys.monitoring.events" namespace.
Each event is represented as a power-of-2 integer constant. To define
a set of events, simply bitwise or the individual events together. For
example, to specify both "PY_RETURN" and "PY_START" events, use the
expression "PY_RETURN | PY_START".

sys.monitoring.events.NO_EVENTS

   An alias for "0" so users can do explicit comparisons like:

      if get_events(DEBUGGER_ID) == NO_EVENTS:
          ...

Los eventos se dividen en tres grupos:


Eventos locales
---------------

Los eventos locales están asociados con la ejecución normal del
programa y ocurren en lugares claramente definidos. Todos los eventos
locales se pueden desactivar. Los eventos locales son:

* "PY_START"

* "PY_RESUME"

* "PY_RETURN"

* "PY_YIELD"

* "CALL"

* "LINE"

* "INSTRUCTION"

* "JUMP"

* "BRANCH"

* "STOP_ITERATION"


Eventos auxiliares
------------------

Los eventos auxiliares se pueden monitorear como otros eventos, pero
están controlados por otros eventos:

* "C_RAISE"

* "C_RETURN"

The "C_RETURN" and "C_RAISE" events are controlled by the "CALL"
event. "C_RETURN" and "C_RAISE" events will only be seen if the
corresponding "CALL" event is being monitored.


Otros eventos
-------------

Otros eventos no están necesariamente vinculados a una ubicación
específica del programa y no se pueden desactivar individualmente.

Los otros eventos que se pueden monitorear son:

* "PY_THROW"

* "PY_UNWIND"

* "RAISE"

* "EXCEPTION_HANDLED"


El evento STOP_ITERATION
------------------------

**PEP 380** specifies that a "StopIteration" exception is raised when
returning a value from a generator or coroutine. However, this is a
very inefficient way to return a value, so some Python
implementations, notably CPython 3.12+, do not raise an exception
unless it would be visible to other code.

To allow tools to monitor for real exceptions without slowing down
generators and coroutines, the "STOP_ITERATION" event is provided.
"STOP_ITERATION" can be locally disabled, unlike "RAISE".

Note that the "STOP_ITERATION" event and the "RAISE" event for a
"StopIteration" exception are equivalent, and are treated as
interchangeable when generating events. Implementations will favor
"STOP_ITERATION" for performance reasons, but may generate a "RAISE"
event with a "StopIteration".


Activar y desactivar eventos
============================

In order to monitor an event, it must be turned on and a corresponding
callback must be registered. Events can be turned on or off by setting
the events either globally or for a particular code object.


Configuración de eventos globalmente
------------------------------------

Los eventos se pueden controlar globalmente modificando el conjunto de
eventos que están siendo monitoreados.

sys.monitoring.get_events(tool_id: int, /) -> int

   Retorna el "int" que representa todos los eventos activos.

sys.monitoring.set_events(tool_id: int, event_set: int, /) -> None

   Activates all events which are set in *event_set*. Raises a
   "ValueError" if *tool_id* is not in use.

No hay eventos activos de forma predeterminada.


Eventos por objeto de código
----------------------------

Events can also be controlled on a per code object basis. The
functions defined below which accept a "types.CodeType" should be
prepared to accept a look-alike object from functions which are not
defined in Python (see Monitoring C API).

sys.monitoring.get_local_events(tool_id: int, code: CodeType, /) -> int

   Returns all the local events for *code*

sys.monitoring.set_local_events(tool_id: int, code: CodeType, event_set: int, /) -> None

   Activates all the local events for *code* which are set in
   *event_set*. Raises a "ValueError" if *tool_id* is not in use.

Los eventos locales se suman a los eventos globales, pero no los
enmascaran. En otras palabras, todos los eventos globales se activarán
para un objeto de código, independientemente de los eventos locales.


Deshabilitando eventos
----------------------

sys.monitoring.DISABLE

   A special value that can be returned from a callback function to
   disable events for the current code location.

Local events can be disabled for a specific code location by returning
"sys.monitoring.DISABLE" from a callback function. This does not
change which events are set, or any other code locations for the same
event.

Deshabilitar eventos para ubicaciones específicas es muy importante
para el monitoreo de alto rendimiento. Por ejemplo, un programa se
puede ejecutar con un depurador sin gastos adicionales si el depurador
desactiva toda la supervisión excepto algunos puntos de interrupción.

sys.monitoring.restart_events() -> None

   Enable all the events that were disabled by
   "sys.monitoring.DISABLE" for all tools.


Registrando funciones de retrollamada
=====================================

Para registrar un invocable para eventos llame

sys.monitoring.register_callback(tool_id: int, event: int, func: Callable | None, /) -> Callable | None

   Registers the callable *func* for the *event* with the given
   *tool_id*

   If another callback was registered for the given *tool_id* and
   *event*, it is unregistered and returned. Otherwise
   "register_callback()" returns "None".

Funciones pueden ser canceladas llamando
"sys.monitoring.register_callback(tool_id, event, None)".

Las funciones de retrollamada se pueden registrar y cancelar en
cualquier momento.

Registering or unregistering a callback function will generate a
"sys.audit()" event.


Argumentos de la función de retrollamada
----------------------------------------

sys.monitoring.MISSING

   A special value that is passed to a callback function to indicate
   that there are no arguments to the call.

Cuando ocurre un evento activo, se llama a la función de retrollamada
registrada. Diferentes eventos proporcionarán a la función de
retrollamada con diferentes argumentos, de la siguiente manera:

* "PY_START" and "PY_RESUME":

     func(code: CodeType, instruction_offset: int) -> DISABLE | Any

* "PY_RETURN" and "PY_YIELD":

     func(code: CodeType, instruction_offset: int, retval: object) -> DISABLE | Any

* "CALL", "C_RAISE" and "C_RETURN":

     func(code: CodeType, instruction_offset: int, callable: object, arg0: object | MISSING) -> DISABLE | Any

  If there are no arguments, *arg0* is set to
  "sys.monitoring.MISSING".

* "RAISE", "RERAISE", "EXCEPTION_HANDLED", "PY_UNWIND", "PY_THROW" and
  "STOP_ITERATION":

     func(code: CodeType, instruction_offset: int, exception: BaseException) -> DISABLE | Any

* "LINE":

     func(code: CodeType, line_number: int) -> DISABLE | Any

* "BRANCH" and "JUMP":

     func(code: CodeType, instruction_offset: int, destination_offset: int) -> DISABLE | Any

  Note that the *destination_offset* is where the code will next
  execute. For an untaken branch this will be the offset of the
  instruction following the branch.

* "INSTRUCTION":

     func(code: CodeType, instruction_offset: int) -> DISABLE | Any
