Issue #14785: Add sys._debugmallocstats() to help debug low-level memory allocation issues

Author: davidmalcolm

Doc/library/sys.rst

@@ -106,6 +106,22 @@ always available.
  This function should be used for internal and specialized purposes only.
 
 
+.. function:: _debugmallocstats()
+
+ Print low-level information to stderr about the state of CPython's memory
+ allocator.
+
+ If Python is configured --with-pydebug, it also performs some expensive
+ internal consistency checks.
+
+ .. versionadded:: 3.3
+
+ .. impl-detail::
+
+ This function is specific to CPython. The exact output format is not
+ defined here, and may change.
+
+
 .. data:: dllhandle
 
  Integer specifying the handle of the Python DLL. Availability: Windows.

Include/dictobject.h

@@ -111,6 +111,7 @@ PyAPI_FUNC(int) PyDict_DelItemString(PyObject *dp, const char *key);
 #ifndef Py_LIMITED_API
 int _PyObjectDict_SetItem(PyTypeObject *tp, PyObject **dictptr, PyObject *name, PyObject *value);
 PyObject *_PyDict_LoadGlobal(PyDictObject *, PyDictObject *, PyObject *);
+PyAPI_FUNC(void) _PyDict_DebugMallocStats(FILE *out);
 #endif
 
 #ifdef __cplusplus

Include/floatobject.h

@@ -110,6 +110,8 @@ PyAPI_FUNC(double) _PyFloat_Unpack8(const unsigned char *p, int le);
 /* free list api */
 PyAPI_FUNC(int) PyFloat_ClearFreeList(void);
 
+PyAPI_FUNC(void) _PyFloat_DebugMallocStats(FILE* out);
+
 /* Format the object based on the format_spec, as defined in PEP 3101
  (Advanced String Formatting). */
 PyAPI_FUNC(int) _PyFloat_FormatAdvancedWriter(

Include/frameobject.h

@@ -79,6 +79,8 @@ PyAPI_FUNC(void) PyFrame_FastToLocals(PyFrameObject *);
 
 PyAPI_FUNC(int) PyFrame_ClearFreeList(void);
 
+PyAPI_FUNC(void) _PyFrame_DebugMallocStats(FILE *out);
+
 /* Return the line of code the frame is currently executing. */
 PyAPI_FUNC(int) PyFrame_GetLineNumber(PyFrameObject *);
 

Include/listobject.h

@@ -64,6 +64,7 @@ PyAPI_FUNC(PyObject *) PyList_AsTuple(PyObject *);
 PyAPI_FUNC(PyObject *) _PyList_Extend(PyListObject *, PyObject *);
 
 PyAPI_FUNC(int) PyList_ClearFreeList(void);
+PyAPI_FUNC(void) _PyList_DebugMallocStats(FILE *out);
 #endif
 
 /* Macro, trading safety for speed */

Include/methodobject.h

@@ -82,6 +82,11 @@ typedef struct {
 
 PyAPI_FUNC(int) PyCFunction_ClearFreeList(void);
 
+#ifndef Py_LIMITED_API
+PyAPI_FUNC(void) _PyCFunction_DebugMallocStats(FILE *out);
+PyAPI_FUNC(void) _PyMethod_DebugMallocStats(FILE *out);
+#endif
+
 #ifdef __cplusplus
 }
 #endif

Include/object.h

@@ -977,6 +977,14 @@ PyAPI_DATA(PyObject *) _PyTrash_delete_later;
  else \
  _PyTrash_deposit_object((PyObject*)op);
 
+#ifndef Py_LIMITED_API
+PyAPI_FUNC(void)
+_PyDebugAllocatorStats(FILE *out, const char *block_name, int num_blocks,
+ size_t sizeof_block);
+PyAPI_FUNC(void)
+_PyObject_DebugTypeStats(FILE *out);
+#endif /* ifndef Py_LIMITED_API */
+
 #ifdef __cplusplus
 }
 #endif

Include/objimpl.h

@@ -101,13 +101,15 @@ PyAPI_FUNC(void) PyObject_Free(void *);
 
 /* Macros */
 #ifdef WITH_PYMALLOC
+#ifndef Py_LIMITED_API
+PyAPI_FUNC(void) _PyObject_DebugMallocStats(FILE *out);
+#endif /* #ifndef Py_LIMITED_API */
 #ifdef PYMALLOC_DEBUG /* WITH_PYMALLOC && PYMALLOC_DEBUG */
 PyAPI_FUNC(void *) _PyObject_DebugMalloc(size_t nbytes);
 PyAPI_FUNC(void *) _PyObject_DebugRealloc(void *p, size_t nbytes);
 PyAPI_FUNC(void) _PyObject_DebugFree(void *p);
 PyAPI_FUNC(void) _PyObject_DebugDumpAddress(const void *p);
 PyAPI_FUNC(void) _PyObject_DebugCheckAddress(const void *p);
-PyAPI_FUNC(void) _PyObject_DebugMallocStats(void);
 PyAPI_FUNC(void *) _PyObject_DebugMallocApi(char api, size_t nbytes);
 PyAPI_FUNC(void *) _PyObject_DebugReallocApi(char api, void *p, size_t nbytes);
 PyAPI_FUNC(void) _PyObject_DebugFreeApi(char api, void *p);

Include/setobject.h

@@ -101,6 +101,7 @@ PyAPI_FUNC(PyObject *) PySet_Pop(PyObject *set);
 PyAPI_FUNC(int) _PySet_Update(PyObject *set, PyObject *iterable);
 
 PyAPI_FUNC(int) PySet_ClearFreeList(void);
+PyAPI_FUNC(void) _PySet_DebugMallocStats(FILE *out);
 #endif
 
 #ifdef __cplusplus

Include/tupleobject.h

@@ -63,6 +63,9 @@ PyAPI_FUNC(void) _PyTuple_MaybeUntrack(PyObject *);
 #endif
 
 PyAPI_FUNC(int) PyTuple_ClearFreeList(void);
+#ifndef Py_LIMITED_API
+PyAPI_FUNC(void) _PyTuple_DebugMallocStats(FILE *out);
+#endif /* Py_LIMITED_API */
 
 #ifdef __cplusplus
 }