GH-103082: Implementation of PEP 669: Low Impact Monitoring for CPython (GH-103083)

* The majority of the monitoring code is in instrumentation.c

* The new instrumentation bytecodes are in bytecodes.c

* legacy_tracing.c adapts the new API to the old sys.setrace and sys.setprofile APIs

1 files changed, 43 insertions, 2 deletions

diff --git a/Include/cpython/code.h b/Include/cpython/code.h
index abcf125..6bead36 100644
--- a/Include/cpython/code.h
+++ b/Include/cpython/code.h
@@ -3,10 +3,22 @@
 #ifndef Py_LIMITED_API
 #ifndef Py_CODE_H
 #define Py_CODE_H
+
 #ifdef __cplusplus
 extern "C" {
 #endif
 
+
+/* Count of all "real" monitoring events (not derived from other events) */
+#define PY_MONITORING_UNGROUPED_EVENTS 14
+/* Count of all  monitoring events */
+#define PY_MONITORING_EVENTS 16
+
+/* Table of which tools are active for each monitored event. */
+typedef struct _Py_Monitors {
+    uint8_t tools[PY_MONITORING_UNGROUPED_EVENTS];
+} _Py_Monitors;
+
 /* Each instruction in a code object is a fixed-width value,
  * currently 2 bytes: 1-byte opcode + 1-byte oparg.  The EXTENDED_ARG
  * opcode allows for larger values but the current limit is 3 uses
@@ -56,6 +68,35 @@ typedef struct {
     PyObject *_co_freevars;
 } _PyCoCached;
 
+/* Ancilliary data structure used for instrumentation.
+   Line instrumentation creates an array of
+   these. One entry per code unit.*/
+typedef struct {
+    uint8_t original_opcode;
+    int8_t line_delta;
+} _PyCoLineInstrumentationData;
+
+/* Main data structure used for instrumentation.
+ * This is allocated when needed for instrumentation
+ */
+typedef struct {
+    /* Monitoring specific to this code object */
+    _Py_Monitors local_monitors;
+    /* Monitoring that is active on this code object */
+    _Py_Monitors active_monitors;
+    /* The tools that are to be notified for events for the matching code unit */
+    uint8_t *tools;
+    /* Information to support line events */
+    _PyCoLineInstrumentationData *lines;
+    /* The tools that are to be notified for line events for the matching code unit */
+    uint8_t *line_tools;
+    /* Information to support instruction events */
+    /* The underlying instructions, which can themselves be instrumented */
+    uint8_t *per_instruction_opcodes;
+    /* The tools that are to be notified for instruction events for the matching code unit */
+    uint8_t *per_instruction_tools;
+} _PyCoMonitoringData;
+
 // To avoid repeating ourselves in deepfreeze.py, all PyCodeObject members are
 // defined in this macro:
 #define _PyCode_DEF(SIZE) {                                                    \
@@ -87,7 +128,6 @@ typedef struct {
     PyObject *co_exceptiontable;   /* Byte string encoding exception handling  \
                                       table */                                 \
     int co_flags;                  /* CO_..., see below */                     \
-    short _co_linearray_entry_size;  /* Size of each entry in _co_linearray */ \
                                                                                \
     /* The rest are not so impactful on performance. */                        \
     int co_argcount;              /* #arguments, except *args */               \
@@ -114,8 +154,9 @@ typedef struct {
     PyObject *co_linetable;       /* bytes object that holds location info */  \
     PyObject *co_weakreflist;     /* to support weakrefs to code objects */    \
     _PyCoCached *_co_cached;      /* cached co_* attributes */                 \
+    uint64_t _co_instrumentation_version; /* current instrumentation version */  \
+    _PyCoMonitoringData *_co_monitoring; /* Monitoring data */                 \
     int _co_firsttraceable;       /* index of first traceable instruction */   \
-    char *_co_linearray;          /* array of line offsets */                  \
     /* Scratch space for extra data relating to the code object.               \
        Type is a void* to keep the format private in codeobject.c to force     \
        people to go through the proper APIs. */                                \