Make all PEP-669 events local

We make all the events of the low-impact monitoring API local,
shifting the distinction to whether they are instrumented or
non-instrumented.

Author: P403n1x87

Doc/library/sys.monitoring.rst

@@ -179,9 +179,14 @@ events, use the expression ``PY_RETURN | PY_START``.
 Local events
 ''''''''''''
 
-Local events are associated with normal execution of the program and happen
-at clearly defined locations. All local events can be disabled.
-The local events are:
+Local events are associated with execution of a particular code object and
+can all be disabled via :data:`DISABLE`. There are two kinds, which differ
+in how :data:`DISABLE` takes effect.
+
+**Instrumented local events** require bytecode instrumentation and fire at
+clearly defined instruction locations within a function. Returning
+:data:`DISABLE` from a callback disables the event at that specific
+code location only, leaving all other locations unaffected:
 
 * :monitoring-event:`PY_START`
 * :monitoring-event:`PY_RESUME`
@@ -195,6 +200,24 @@ The local events are:
 * :monitoring-event:`BRANCH_RIGHT`
 * :monitoring-event:`STOP_ITERATION`
 
+**Non-instrumented local events** do not require bytecode instrumentation and
+are not tied to a specific instruction. They can fire at any point within
+a function where the triggering condition occurs. Returning :data:`DISABLE`
+from a callback disables the event for the entire code object (for the
+current tool):
+
+* :monitoring-event:`PY_UNWIND`
+* :monitoring-event:`EXCEPTION_HANDLED`
+* :monitoring-event:`RAISE`
+* :monitoring-event:`PY_THROW`
+* :monitoring-event:`RERAISE`
+
+.. versionchanged:: 3.15
+   :monitoring-event:`PY_UNWIND`, :monitoring-event:`EXCEPTION_HANDLED`,
+   :monitoring-event:`RAISE`, :monitoring-event:`PY_THROW`, and
+   :monitoring-event:`RERAISE` are now local events and can be disabled
+   via :data:`DISABLE`.
+
 Deprecated event
 ''''''''''''''''
 
@@ -205,6 +228,8 @@ Using :monitoring-event:`BRANCH_LEFT` and :monitoring-event:`BRANCH_RIGHT`
 events will give much better performance as they can be disabled
 independently.
 
+.. _monitoring-ancillary-events:
+
 Ancillary events
 ''''''''''''''''
 
@@ -220,22 +245,6 @@ are controlled by the :monitoring-event:`CALL` event.
 seen if the corresponding :monitoring-event:`CALL` event is being monitored.
 
 
-.. _monitoring-event-global:
-
-Other events
-''''''''''''
-
-Other events are not necessarily tied to a specific location in the
-program and cannot be individually disabled via :data:`DISABLE`.
-
-The other events that can be monitored are:
-
-* :monitoring-event:`PY_THROW`
-* :monitoring-event:`PY_UNWIND`
-* :monitoring-event:`RAISE`
-* :monitoring-event:`EXCEPTION_HANDLED`
-
-
 The STOP_ITERATION event
 ''''''''''''''''''''''''
 
@@ -247,8 +256,7 @@ 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 :monitoring-event:`STOP_ITERATION` event is provided.
-:monitoring-event:`STOP_ITERATION` can be locally disabled, unlike
-:monitoring-event:`RAISE`.
+:monitoring-event:`STOP_ITERATION` can be locally disabled.
 
 Note that the :monitoring-event:`STOP_ITERATION` event and the
 :monitoring-event:`RAISE` event for a :exc:`StopIteration` exception are
@@ -307,22 +315,23 @@ Disabling events
 .. data:: DISABLE
 
    A special value that can be returned from a callback function to disable
-   events for the current code location.
-
-:ref:`Local events <monitoring-event-local>` can be disabled for a specific code
-location by returning :data:`sys.monitoring.DISABLE` from a callback function.
-This does not change which events are set, or any other code locations for the
-same event.
-
-Disabling events for specific locations is very important for high
-performance monitoring. For example, a program can be run under a
-debugger with no overhead if the debugger disables all monitoring
-except for a few breakpoints.
-
-If :data:`DISABLE` is returned by a callback for a
-:ref:`global event <monitoring-event-global>`, :exc:`ValueError` will be raised
-by the interpreter in a non-specific location (that is, no traceback will be
-provided).
+   the event.
+
+All :ref:`local events <monitoring-event-local>` can be disabled by returning
+:data:`sys.monitoring.DISABLE` from a callback function. This does not change
+which events are set globally.
+
+For :ref:`instrumented local events <monitoring-event-local>`, :data:`DISABLE`
+disables the event at the specific code location where it fired only, leaving
+all other locations for the same event unaffected.
+
+For :ref:`non-instrumented local events <monitoring-event-local>`,
+:data:`DISABLE` disables the event for the entire code object (for the current
+tool).
+
+Disabling events is very important for high performance monitoring. For
+example, a program can be run under a debugger with no overhead if the
+debugger disables all monitoring except for a few breakpoints.
 
 .. function:: restart_events() -> None
 

Include/cpython/monitoring.h

@@ -8,8 +8,8 @@ extern "C" {
 // There is currently no limited API for monitoring
 
 
-/* Local events.
- * Some of these require bytecode instrumentation */
+/* Local events (tracked per code object).
+ * Events 0-10 require bytecode instrumentation; 11-15 do not. */
 
 #define PY_MONITORING_EVENT_PY_START 0
 #define PY_MONITORING_EVENT_PY_RESUME 1
@@ -27,18 +27,14 @@ extern "C" {
 ((ev) <= PY_MONITORING_EVENT_STOP_ITERATION)
 
 #define PY_MONITORING_EVENT_PY_UNWIND 11
-
-#define PY_MONITORING_IS_LOCAL_EVENT(ev) \
-((ev) < _PY_MONITORING_LOCAL_EVENTS)
-
-
-/* Other events, mainly exceptions */
-
 #define PY_MONITORING_EVENT_EXCEPTION_HANDLED 12
 #define PY_MONITORING_EVENT_RAISE 13
 #define PY_MONITORING_EVENT_PY_THROW 14
 #define PY_MONITORING_EVENT_RERAISE 15
 
+#define PY_MONITORING_IS_LOCAL_EVENT(ev) \
+((ev) < _PY_MONITORING_UNGROUPED_EVENTS)
+
 
 /* Ancillary events */
 

Include/internal/pycore_ceval.h

@@ -329,7 +329,7 @@ PyObject * _PyEval_ImportNameWithImport(
 PyAPI_FUNC(PyObject *)_PyEval_MatchClass(PyThreadState *tstate, PyObject *subject, PyObject *type, Py_ssize_t nargs, PyObject *kwargs);
 PyAPI_FUNC(PyObject *)_PyEval_MatchKeys(PyThreadState *tstate, PyObject *map, PyObject *keys);
 PyAPI_FUNC(void) _PyEval_MonitorRaise(PyThreadState *tstate, _PyInterpreterFrame *frame, _Py_CODEUNIT *instr);
-PyAPI_FUNC(bool) _PyEval_NoToolsForUnwind(PyThreadState *tstate);
+PyAPI_FUNC(bool) _PyEval_NoToolsForUnwind(PyThreadState *tstate, _PyInterpreterFrame *frame);
 PyAPI_FUNC(int) _PyEval_UnpackIterableStackRef(PyThreadState *tstate, PyObject *v, int argcnt, int argcntafter, _PyStackRef *sp);
 PyAPI_FUNC(void) _PyEval_FrameClearAndPop(PyThreadState *tstate, _PyInterpreterFrame *frame);
 PyAPI_FUNC(PyObject **) _PyObjectArray_FromStackRefArray(_PyStackRef *input, Py_ssize_t nargs, PyObject **scratch);

Include/internal/pycore_instruments.h

@@ -73,16 +73,15 @@ PyAPI_DATA(PyObject) _PyInstrumentation_DISABLE;
 
 /* Total tool ids available */
 #define  PY_MONITORING_TOOL_IDS 8
-/* Count of all local monitoring events */
-#define  _PY_MONITORING_LOCAL_EVENTS 12
-/* Count of all "real" monitoring events (not derived from other events) */
+/* Count of all "real" monitoring events (not derived from other events).
+ * All ungrouped events are now local events. */
 #define _PY_MONITORING_UNGROUPED_EVENTS 16
 /* Count of all  monitoring events */
 #define _PY_MONITORING_EVENTS 19
 
 /* Tables of which tools are active for each monitored event. */
 typedef struct _Py_LocalMonitors {
-    uint8_t tools[_PY_MONITORING_LOCAL_EVENTS];
+    uint8_t tools[_PY_MONITORING_UNGROUPED_EVENTS];
 } _Py_LocalMonitors;
 
 typedef struct _Py_GlobalMonitors {