Monitoring C API¶

Added in version 3.13.

An extension may need to interact with the event monitoring system. Subscribing to events and registering callbacks can be done via the Python API exposed in sys.monitoring.

Generating Execution Events¶

The functions below make it possible for an extension to fire monitoring events as it emulates the execution of Python code. Each of these functions accepts a PyMonitoringState struct which contains concise information about the activation state of events, as well as the event arguments, which include a PyObject* representing the code object, the instruction offset and sometimes additional, event-specific arguments (see sys.monitoring for details about the signatures of the different event callbacks). The codelike argument should be an instance of types.CodeType or of a type that emulates it.

The VM disables tracing when firing an event, so there is no need for user code to do that.

Monitoring functions should not be called with an exception set, except those listed below as working with the current exception.

type PyMonitoringState¶

Representation of the state of an event type. It is allocated by the user while its contents are maintained by the monitoring API functions described below.

All of the functions below return 0 on success and -1 (with an exception set) on error.

See sys.monitoring for descriptions of the events.

int PyMonitoring_FirePyStartEvent(PyMonitoringState *state, PyObject *codelike, int32_t offset)¶

Fire a PY_START event.

int PyMonitoring_FirePyResumeEvent(PyMonitoringState *state, PyObject *codelike, int32_t offset)¶

Fire a PY_RESUME event.

int PyMonitoring_FirePyReturnEvent(PyMonitoringState *state, PyObject *codelike, int32_t offset, PyObject *retval)¶

Fire a PY_RETURN event.

int PyMonitoring_FirePyYieldEvent(PyMonitoringState *state, PyObject *codelike, int32_t offset, PyObject *retval)¶

Fire a PY_YIELD event.

int PyMonitoring_FireCallEvent(PyMonitoringState *state, PyObject *codelike, int32_t offset, PyObject *callable, PyObject *arg0)¶

Fire a CALL event.

int PyMonitoring_FireLineEvent(PyMonitoringState *state, PyObject *codelike, int32_t offset, int lineno)¶

Fire a LINE event.

int PyMonitoring_FireJumpEvent(PyMonitoringState *state, PyObject *codelike, int32_t offset, PyObject *target_offset)¶

Fire a JUMP event.

int PyMonitoring_FireBranchLeftEvent(PyMonitoringState *state, PyObject *codelike, int32_t offset, PyObject *target_offset)¶

Fire a BRANCH_LEFT event.

int PyMonitoring_FireBranchRightEvent(PyMonitoringState *state, PyObject *codelike, int32_t offset, PyObject *target_offset)¶

Fire a BRANCH_RIGHT event.

int PyMonitoring_FireCReturnEvent(PyMonitoringState *state, PyObject *codelike, int32_t offset, PyObject *retval)¶

Fire a C_RETURN event.

int PyMonitoring_FirePyThrowEvent(PyMonitoringState *state, PyObject *codelike, int32_t offset)¶

Fire a PY_THROW event with the current exception (as returned by PyErr_GetRaisedException()).

int PyMonitoring_FireRaiseEvent(PyMonitoringState *state, PyObject *codelike, int32_t offset)¶

Fire a RAISE event with the current exception (as returned by PyErr_GetRaisedException()).

int PyMonitoring_FireCRaiseEvent(PyMonitoringState *state, PyObject *codelike, int32_t offset)¶

Fire a C_RAISE event with the current exception (as returned by PyErr_GetRaisedException()).

int PyMonitoring_FireReraiseEvent(PyMonitoringState *state, PyObject *codelike, int32_t offset)¶

Fire a RERAISE event with the current exception (as returned by PyErr_GetRaisedException()).

int PyMonitoring_FireExceptionHandledEvent(PyMonitoringState *state, PyObject *codelike, int32_t offset)¶

Fire an EXCEPTION_HANDLED event with the current exception (as returned by PyErr_GetRaisedException()).

int PyMonitoring_FirePyUnwindEvent(PyMonitoringState *state, PyObject *codelike, int32_t offset)¶

Fire a PY_UNWIND event with the current exception (as returned by PyErr_GetRaisedException()).

int PyMonitoring_FireStopIterationEvent(PyMonitoringState *state, PyObject *codelike, int32_t offset, PyObject *value)¶

Fire a STOP_ITERATION event. If value is an instance of StopIteration, it is used. Otherwise, a new StopIteration instance is created with value as its argument.