#include "Python.h"
#include "pycore_pymem.h"
#include
/* Defined in tracemalloc.c */
extern void _PyMem_DumpTraceback(int fd, const void *ptr);
/* Python's malloc wrappers (see pymem.h) */
#undef uint
#define uint unsigned int /* assuming >= 16 bits */
/* Forward declaration */
static void* _PyMem_DebugRawMalloc(void *ctx, size_t size);
static void* _PyMem_DebugRawCalloc(void *ctx, size_t nelem, size_t elsize);
static void* _PyMem_DebugRawRealloc(void *ctx, void *ptr, size_t size);
static void _PyMem_DebugRawFree(void *ctx, void *ptr);
static void* _PyMem_DebugMalloc(void *ctx, size_t size);
static void* _PyMem_DebugCalloc(void *ctx, size_t nelem, size_t elsize);
static void* _PyMem_DebugRealloc(void *ctx, void *ptr, size_t size);
static void _PyMem_DebugFree(void *ctx, void *p);
static void _PyObject_DebugDumpAddress(const void *p);
static void _PyMem_DebugCheckAddress(char api_id, const void *p);
static void _PyMem_SetupDebugHooksDomain(PyMemAllocatorDomain domain);
#if defined(__has_feature) /* Clang */
# if __has_feature(address_sanitizer) /* is ASAN enabled? */
# define _Py_NO_SANITIZE_ADDRESS \
__attribute__((no_sanitize("address")))
# endif
# if __has_feature(thread_sanitizer) /* is TSAN enabled? */
# define _Py_NO_SANITIZE_THREAD __attribute__((no_sanitize_thread))
# endif
# if __has_feature(memory_sanitizer) /* is MSAN enabled? */
# define _Py_NO_SANITIZE_MEMORY __attribute__((no_sanitize_memory))
# endif
#elif defined(__GNUC__)
# if defined(__SANITIZE_ADDRESS__) /* GCC 4.8+, is ASAN enabled? */
# define _Py_NO_SANITIZE_ADDRESS \
__attribute__((no_sanitize_address))
# endif
// TSAN is supported since GCC 5.1, but __SANITIZE_THREAD__ macro
// is provided only since GCC 7.
# if __GNUC__ > 5 || (__GNUC__ == 5 && __GNUC_MINOR__ >= 1)
# define _Py_NO_SANITIZE_THREAD __attribute__((no_sanitize_thread))
# endif
#endif
#ifndef _Py_NO_SANITIZE_ADDRESS
# define _Py_NO_SANITIZE_ADDRESS
#endif
#ifndef _Py_NO_SANITIZE_THREAD
# define _Py_NO_SANITIZE_THREAD
#endif
#ifndef _Py_NO_SANITIZE_MEMORY
# define _Py_NO_SANITIZE_MEMORY
#endif
#ifdef WITH_PYMALLOC
#ifdef MS_WINDOWS
# include
#elif defined(HAVE_MMAP)
# include
# ifdef MAP_ANONYMOUS
# define ARENAS_USE_MMAP
# endif
#endif
/* Forward declaration */
static void* _PyObject_Malloc(void *ctx, size_t size);
static void* _PyObject_Calloc(void *ctx, size_t nelem, size_t elsize);
static void _PyObject_Free(void *ctx, void *p);
static void* _PyObject_Realloc(void *ctx, void *ptr, size_t size);
#endif
/* bpo-35053: Declare tracemalloc configuration here rather than
Modules/_tracemalloc.c because _tracemalloc can be compiled as dynamic
library, whereas _Py_NewReference() requires it. */
struct _PyTraceMalloc_Config _Py_tracemalloc_config = _PyTraceMalloc_Config_INIT;
static void *
_PyMem_RawMalloc(void *ctx, size_t size)
{
/* PyMem_RawMalloc(0) means malloc(1). Some systems would return NULL
for malloc(0), which would be treated as an error. Some platforms would
return a pointer with no memory behind it, which would break pymalloc.
To solve these problems, allocate an extra byte. */
if (size == 0)
size = 1;
return malloc(size);
}
static void *
_PyMem_RawCalloc(void *ctx, size_t nelem, size_t elsize)
{
/* PyMem_RawCalloc(0, 0) means calloc(1, 1). Some systems would return NULL
for calloc(0, 0), which would be treated as an error. Some platforms
would return a pointer with no memory behind it, which would break
pymalloc. To solve these problems, allocate an extra byte. */
if (nelem == 0 || elsize == 0) {
nelem = 1;
elsize = 1;
}
return calloc(nelem, elsize);
}
static void *
_PyMem_RawRealloc(void *ctx, void *ptr, size_t size)
{
if (size == 0)
size = 1;
return realloc(ptr, size);
}
static void
_PyMem_RawFree(void *ctx, void *ptr)
{
free(ptr);
}
#ifdef MS_WINDOWS
static void *
_PyObject_ArenaVirtualAlloc(void *ctx, size_t size)
{
return VirtualAlloc(NULL, size,
MEM_COMMIT | MEM_RESERVE, PAGE_READWRITE);
}
static void
_PyObject_ArenaVirtualFree(void *ctx, void *ptr, size_t size)
{
VirtualFree(ptr, 0, MEM_RELEASE);
}
#elif defined(ARENAS_USE_MMAP)
static void *
_PyObject_ArenaMmap(void *ctx, size_t size)
{
void *ptr;
ptr = mmap(NULL, size, PROT_READ|PROT_WRITE,
MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
if (ptr == MAP_FAILED)
return NULL;
assert(ptr != NULL);
return ptr;
}
static void
_PyObject_ArenaMunmap(void *ctx, void *ptr, size_t size)
{
munmap(ptr, size);
}
#else
static void *
_PyObject_ArenaMalloc(void *ctx, size_t size)
{
return malloc(size);
}
static void
_PyObject_ArenaFree(void *ctx, void *ptr, size_t size)
{
free(ptr);
}
#endif
#define MALLOC_ALLOC {NULL, _PyMem_RawMalloc, _PyMem_RawCalloc, _PyMem_RawRealloc, _PyMem_RawFree}
#ifdef WITH_PYMALLOC
# define PYMALLOC_ALLOC {NULL, _PyObject_Malloc, _PyObject_Calloc, _PyObject_Realloc, _PyObject_Free}
#endif
#define PYRAW_ALLOC MALLOC_ALLOC
#ifdef WITH_PYMALLOC
# define PYOBJ_ALLOC PYMALLOC_ALLOC
#else
# define PYOBJ_ALLOC MALLOC_ALLOC
#endif
#define PYMEM_ALLOC PYOBJ_ALLOC
typedef struct {
/* We tag each block with an API ID in order to tag API violations */
char api_id;
PyMemAllocatorEx alloc;
} debug_alloc_api_t;
static struct {
debug_alloc_api_t raw;
debug_alloc_api_t mem;
debug_alloc_api_t obj;
} _PyMem_Debug = {
{'r', PYRAW_ALLOC},
{'m', PYMEM_ALLOC},
{'o', PYOBJ_ALLOC}
};
#define PYDBGRAW_ALLOC \
{&_PyMem_Debug.raw, _PyMem_DebugRawMalloc, _PyMem_DebugRawCalloc, _PyMem_DebugRawRealloc, _PyMem_DebugRawFree}
#define PYDBGMEM_ALLOC \
{&_PyMem_Debug.mem, _PyMem_DebugMalloc, _PyMem_DebugCalloc, _PyMem_DebugRealloc, _PyMem_DebugFree}
#define PYDBGOBJ_ALLOC \
{&_PyMem_Debug.obj, _PyMem_DebugMalloc, _PyMem_DebugCalloc, _PyMem_DebugRealloc, _PyMem_DebugFree}
#ifdef Py_DEBUG
static PyMemAllocatorEx _PyMem_Raw = PYDBGRAW_ALLOC;
static PyMemAllocatorEx _PyMem = PYDBGMEM_ALLOC;
static PyMemAllocatorEx _PyObject = PYDBGOBJ_ALLOC;
#else
static PyMemAllocatorEx _PyMem_Raw = PYRAW_ALLOC;
static PyMemAllocatorEx _PyMem = PYMEM_ALLOC;
static PyMemAllocatorEx _PyObject = PYOBJ_ALLOC;
#endif
static int
pymem_set_default_allocator(PyMemAllocatorDomain domain, int debug,
PyMemAllocatorEx *old_alloc)
{
if (old_alloc != NULL) {
PyMem_GetAllocator(domain, old_alloc);
}
PyMemAllocatorEx new_alloc;
switch(domain)
{
case PYMEM_DOMAIN_RAW:
new_alloc = (PyMemAllocatorEx)PYRAW_ALLOC;
break;
case PYMEM_DOMAIN_MEM:
new_alloc = (PyMemAllocatorEx)PYMEM_ALLOC;
break;
case PYMEM_DOMAIN_OBJ:
new_alloc = (PyMemAllocatorEx)PYOBJ_ALLOC;
break;
default:
/* unknown domain */
return -1;
}
PyMem_SetAllocator(domain, &new_alloc);
if (debug) {
_PyMem_SetupDebugHooksDomain(domain);
}
return 0;
}
int
_PyMem_SetDefaultAllocator(PyMemAllocatorDomain domain,
PyMemAllocatorEx *old_alloc)
{
#ifdef Py_DEBUG
const int debug = 1;
#else
const int debug = 0;
#endif
return pymem_set_default_allocator(domain, debug, old_alloc);
}
int
_PyMem_GetAllocatorName(const char *name, PyMemAllocatorName *allocator)
{
if (name == NULL || *name == '\0') {
/* PYTHONMALLOC is empty or is not set or ignored (-E/-I command line
nameions): use default memory allocators */
*allocator = PYMEM_ALLOCATOR_DEFAULT;
}
else if (strcmp(name, "default") == 0) {
*allocator = PYMEM_ALLOCATOR_DEFAULT;
}
else if (strcmp(name, "debug") == 0) {
*allocator = PYMEM_ALLOCATOR_DEBUG;
}
#ifdef WITH_PYMALLOC
else if (strcmp(name, "pymalloc") == 0) {
*allocator = PYMEM_ALLOCATOR_PYMALLOC;
}
else if (strcmp(name, "pymalloc_debug") == 0) {
*allocator = PYMEM_ALLOCATOR_PYMALLOC_DEBUG;
}
#endif
else if (strcmp(name, "malloc") == 0) {
*allocator = PYMEM_ALLOCATOR_MALLOC;
}
else if (strcmp(name, "malloc_debug") == 0) {
*allocator = PYMEM_ALLOCATOR_MALLOC_DEBUG;
}
else {
/* unknown allocator */
return -1;
}
return 0;
}
int
_PyMem_SetupAllocators(PyMemAllocatorName allocator)
{
switch (allocator) {
case PYMEM_ALLOCATOR_NOT_SET:
/* do nothing */
break;
case PYMEM_ALLOCATOR_DEFAULT:
(void)_PyMem_SetDefaultAllocator(PYMEM_DOMAIN_RAW, NULL);
(void)_PyMem_SetDefaultAllocator(PYMEM_DOMAIN_MEM, NULL);
(void)_PyMem_SetDefaultAllocator(PYMEM_DOMAIN_OBJ, NULL);
break;
case PYMEM_ALLOCATOR_DEBUG:
(void)pymem_set_default_allocator(PYMEM_DOMAIN_RAW, 1, NULL);
(void)pymem_set_default_allocator(PYMEM_DOMAIN_MEM, 1, NULL);
(void)pymem_set_default_allocator(PYMEM_DOMAIN_OBJ, 1, NULL);
break;
#ifdef WITH_PYMALLOC
case PYMEM_ALLOCATOR_PYMALLOC:
case PYMEM_ALLOCATOR_PYMALLOC_DEBUG:
{
PyMemAllocatorEx malloc_alloc = MALLOC_ALLOC;
PyMem_SetAllocator(PYMEM_DOMAIN_RAW, &malloc_alloc);
PyMemAllocatorEx pymalloc = PYMALLOC_ALLOC;
PyMem_SetAllocator(PYMEM_DOMAIN_MEM, &pymalloc);
PyMem_SetAllocator(PYMEM_DOMAIN_OBJ, &pymalloc);
if (allocator == PYMEM_ALLOCATOR_PYMALLOC_DEBUG) {
PyMem_SetupDebugHooks();
}
break;
}
#endif
case PYMEM_ALLOCATOR_MALLOC:
case PYMEM_ALLOCATOR_MALLOC_DEBUG:
{
PyMemAllocatorEx malloc_alloc = MALLOC_ALLOC;
PyMem_SetAllocator(PYMEM_DOMAIN_RAW, &malloc_alloc);
PyMem_SetAllocator(PYMEM_DOMAIN_MEM, &malloc_alloc);
PyMem_SetAllocator(PYMEM_DOMAIN_OBJ, &malloc_alloc);
if (allocator == PYMEM_ALLOCATOR_MALLOC_DEBUG) {
PyMem_SetupDebugHooks();
}
break;
}
default:
/* unknown allocator */
return -1;
}
return 0;
}
static int
pymemallocator_eq(PyMemAllocatorEx *a, PyMemAllocatorEx *b)
{
return (memcmp(a, b, sizeof(PyMemAllocatorEx)) == 0);
}
const char*
_PyMem_GetCurrentAllocatorName(void)
{
PyMemAllocatorEx malloc_alloc = MALLOC_ALLOC;
#ifdef WITH_PYMALLOC
PyMemAllocatorEx pymalloc = PYMALLOC_ALLOC;
#endif
if (pymemallocator_eq(&_PyMem_Raw, &malloc_alloc) &&
pymemallocator_eq(&_PyMem, &malloc_alloc) &&
pymemallocator_eq(&_PyObject, &malloc_alloc))
{
return "malloc";
}
#ifdef WITH_PYMALLOC
if (pymemallocator_eq(&_PyMem_Raw, &malloc_alloc) &&
pymemallocator_eq(&_PyMem, &pymalloc) &&
pymemallocator_eq(&_PyObject, &pymalloc))
{
return "pymalloc";
}
#endif
PyMemAllocatorEx dbg_raw = PYDBGRAW_ALLOC;
PyMemAllocatorEx dbg_mem = PYDBGMEM_ALLOC;
PyMemAllocatorEx dbg_obj = PYDBGOBJ_ALLOC;
if (pymemallocator_eq(&_PyMem_Raw, &dbg_raw) &&
pymemallocator_eq(&_PyMem, &dbg_mem) &&
pymemallocator_eq(&_PyObject, &dbg_obj))
{
/* Debug hooks installed */
if (pymemallocator_eq(&_PyMem_Debug.raw.alloc, &malloc_alloc) &&
pymemallocator_eq(&_PyMem_Debug.mem.alloc, &malloc_alloc) &&
pymemallocator_eq(&_PyMem_Debug.obj.alloc, &malloc_alloc))
{
return "malloc_debug";
}
#ifdef WITH_PYMALLOC
if (pymemallocator_eq(&_PyMem_Debug.raw.alloc, &malloc_alloc) &&
pymemallocator_eq(&_PyMem_Debug.mem.alloc, &pymalloc) &&
pymemallocator_eq(&_PyMem_Debug.obj.alloc, &pymalloc))
{
return "pymalloc_debug";
}
#endif
}
return NULL;
}
#undef MALLOC_ALLOC
#undef PYMALLOC_ALLOC
#undef PYRAW_ALLOC
#undef PYMEM_ALLOC
#undef PYOBJ_ALLOC
#undef PYDBGRAW_ALLOC
#undef PYDBGMEM_ALLOC
#undef PYDBGOBJ_ALLOC
static PyObjectArenaAllocator _PyObject_Arena = {NULL,
#ifdef MS_WINDOWS
_PyObject_ArenaVirtualAlloc, _PyObject_ArenaVirtualFree
#elif defined(ARENAS_USE_MMAP)
_PyObject_ArenaMmap, _PyObject_ArenaMunmap
#else
_PyObject_ArenaMalloc, _PyObject_ArenaFree
#endif
};
#ifdef WITH_PYMALLOC
static int
_PyMem_DebugEnabled(void)
{
return (_PyObject.malloc == _PyMem_DebugMalloc);
}
static int
_PyMem_PymallocEnabled(void)
{
if (_PyMem_DebugEnabled()) {
return (_PyMem_Debug.obj.alloc.malloc == _PyObject_Malloc);
}
else {
return (_PyObject.malloc == _PyObject_Malloc);
}
}
#endif
static void
_PyMem_SetupDebugHooksDomain(PyMemAllocatorDomain domain)
{
PyMemAllocatorEx alloc;
if (domain == PYMEM_DOMAIN_RAW) {
if (_PyMem_Raw.malloc == _PyMem_DebugRawMalloc) {
return;
}
PyMem_GetAllocator(PYMEM_DOMAIN_RAW, &_PyMem_Debug.raw.alloc);
alloc.ctx = &_PyMem_Debug.raw;
alloc.malloc = _PyMem_DebugRawMalloc;
alloc.calloc = _PyMem_DebugRawCalloc;
alloc.realloc = _PyMem_DebugRawRealloc;
alloc.free = _PyMem_DebugRawFree;
PyMem_SetAllocator(PYMEM_DOMAIN_RAW, &alloc);
}
else if (domain == PYMEM_DOMAIN_MEM) {
if (_PyMem.malloc == _PyMem_DebugMalloc) {
return;
}
PyMem_GetAllocator(PYMEM_DOMAIN_MEM, &_PyMem_Debug.mem.alloc);
alloc.ctx = &_PyMem_Debug.mem;
alloc.malloc = _PyMem_DebugMalloc;
alloc.calloc = _PyMem_DebugCalloc;
alloc.realloc = _PyMem_DebugRealloc;
alloc.free = _PyMem_DebugFree;
PyMem_SetAllocator(PYMEM_DOMAIN_MEM, &alloc);
}
else if (domain == PYMEM_DOMAIN_OBJ) {
if (_PyObject.malloc == _PyMem_DebugMalloc) {
return;
}
PyMem_GetAllocator(PYMEM_DOMAIN_OBJ, &_PyMem_Debug.obj.alloc);
alloc.ctx = &_PyMem_Debug.obj;
alloc.malloc = _PyMem_DebugMalloc;
alloc.calloc = _PyMem_DebugCalloc;
alloc.realloc = _PyMem_DebugRealloc;
alloc.free = _PyMem_DebugFree;
PyMem_SetAllocator(PYMEM_DOMAIN_OBJ, &alloc);
}
}
void
PyMem_SetupDebugHooks(void)
{
_PyMem_SetupDebugHooksDomain(PYMEM_DOMAIN_RAW);
_PyMem_SetupDebugHooksDomain(PYMEM_DOMAIN_MEM);
_PyMem_SetupDebugHooksDomain(PYMEM_DOMAIN_OBJ);
}
void
PyMem_GetAllocator(PyMemAllocatorDomain domain, PyMemAllocatorEx *allocator)
{
switch(domain)
{
case PYMEM_DOMAIN_RAW: *allocator = _PyMem_Raw; break;
case PYMEM_DOMAIN_MEM: *allocator = _PyMem; break;
case PYMEM_DOMAIN_OBJ: *allocator = _PyObject; break;
default:
/* unknown domain: set all attributes to NULL */
allocator->ctx = NULL;
allocator->malloc = NULL;
allocator->calloc = NULL;
allocator->realloc = NULL;
allocator->free = NULL;
}
}
void
PyMem_SetAllocator(PyMemAllocatorDomain domain, PyMemAllocatorEx *allocator)
{
switch(domain)
{
case PYMEM_DOMAIN_RAW: _PyMem_Raw = *allocator; break;
case PYMEM_DOMAIN_MEM: _PyMem = *allocator; break;
case PYMEM_DOMAIN_OBJ: _PyObject = *allocator; break;
/* ignore unknown domain */
}
}
void
PyObject_GetArenaAllocator(PyObjectArenaAllocator *allocator)
{
*allocator = _PyObject_Arena;
}
void
PyObject_SetArenaAllocator(PyObjectArenaAllocator *allocator)
{
_PyObject_Arena = *allocator;
}
void *
PyMem_RawMalloc(size_t size)
{
/*
* Limit ourselves to PY_SSIZE_T_MAX bytes to prevent security holes.
* Most python internals blindly use a signed Py_ssize_t to track
* things without checking for overflows or negatives.
* As size_t is unsigned, checking for size < 0 is not required.
*/
if (size > (size_t)PY_SSIZE_T_MAX)
return NULL;
return _PyMem_Raw.malloc(_PyMem_Raw.ctx, size);
}
void *
PyMem_RawCalloc(size_t nelem, size_t elsize)
{
/* see PyMem_RawMalloc() */
if (elsize != 0 && nelem > (size_t)PY_SSIZE_T_MAX / elsize)
return NULL;
return _PyMem_Raw.calloc(_PyMem_Raw.ctx, nelem, elsize);
}
void*
PyMem_RawRealloc(void *ptr, size_t new_size)
{
/* see PyMem_RawMalloc() */
if (new_size > (size_t)PY_SSIZE_T_MAX)
return NULL;
return _PyMem_Raw.realloc(_PyMem_Raw.ctx, ptr, new_size);
}
void PyMem_RawFree(void *ptr)
{
_PyMem_Raw.free(_PyMem_Raw.ctx, ptr);
}
void *
PyMem_Malloc(size_t size)
{
/* see PyMem_RawMalloc() */
if (size > (size_t)PY_SSIZE_T_MAX)
return NULL;
return _PyMem.malloc(_PyMem.ctx, size);
}
void *
PyMem_Calloc(size_t nelem, size_t elsize)
{
/* see PyMem_RawMalloc() */
if (elsize != 0 && nelem > (size_t)PY_SSIZE_T_MAX / elsize)
return NULL;
return _PyMem.calloc(_PyMem.ctx, nelem, elsize);
}
void *
PyMem_Realloc(void *ptr, size_t new_size)
{
/* see PyMem_RawMalloc() */
if (new_size > (size_t)PY_SSIZE_T_MAX)
return NULL;
return _PyMem.realloc(_PyMem.ctx, ptr, new_size);
}
void
PyMem_Free(void *ptr)
{
_PyMem.free(_PyMem.ctx, ptr);
}
wchar_t*
_PyMem_RawWcsdup(const wchar_t *str)
{
assert(str != NULL);
size_t len = wcslen(str);
if (len > (size_t)PY_SSIZE_T_MAX / sizeof(wchar_t) - 1) {
return NULL;
}
size_t size = (len + 1) * sizeof(wchar_t);
wchar_t *str2 = PyMem_RawMalloc(size);
if (str2 == NULL) {
return NULL;
}
memcpy(str2, str, size);
return str2;
}
char *
_PyMem_RawStrdup(const char *str)
{
assert(str != NULL);
size_t size = strlen(str) + 1;
char *copy = PyMem_RawMalloc(size);
if (copy == NULL) {
return NULL;
}
memcpy(copy, str, size);
return copy;
}
char *
_PyMem_Strdup(const char *str)
{
assert(str != NULL);
size_t size = strlen(str) + 1;
char *copy = PyMem_Malloc(size);
if (copy == NULL) {
return NULL;
}
memcpy(copy, str, size);
return copy;
}
void *
PyObject_Malloc(size_t size)
{
/* see PyMem_RawMalloc() */
if (size > (size_t)PY_SSIZE_T_MAX)
return NULL;
return _PyObject.malloc(_PyObject.ctx, size);
}
void *
PyObject_Calloc(size_t nelem, size_t elsize)
{
/* see PyMem_RawMalloc() */
if (elsize != 0 && nelem > (size_t)PY_SSIZE_T_MAX / elsize)
return NULL;
return _PyObject.calloc(_PyObject.ctx, nelem, elsize);
}
void *
PyObject_Realloc(void *ptr, size_t new_size)
{
/* see PyMem_RawMalloc() */
if (new_size > (size_t)PY_SSIZE_T_MAX)
return NULL;
return _PyObject.realloc(_PyObject.ctx, ptr, new_size);
}
void
PyObject_Free(void *ptr)
{
_PyObject.free(_PyObject.ctx, ptr);
}
#ifdef WITH_PYMALLOC
#ifdef WITH_VALGRIND
#include
/* If we're using GCC, use __builtin_expect() to reduce overhead of
the valgrind checks */
#if defined(__GNUC__) && (__GNUC__ > 2) && defined(__OPTIMIZE__)
# define UNLIKELY(value) __builtin_expect((value), 0)
#else
# define UNLIKELY(value) (value)
#endif
/* -1 indicates that we haven't checked that we're running on valgrind yet. */
static int running_on_valgrind = -1;
#endif
/* An object allocator for Python.
Here is an introduction to the layers of the Python memory architecture,
showing where the object allocator is actually used (layer +2), It is
called for every object allocation and deallocation (PyObject_New/Del),
unless the object-specific allocators implement a proprietary allocation
scheme (ex.: ints use a simple free list). This is also the place where
the cyclic garbage collector operates selectively on container objects.
Object-specific allocators
_____ ______ ______ ________
[ int ] [ dict ] [ list ] ... [ string ] Python core |
+3 | | |
_______________________________ | |
[ Python's object allocator ] | |
+2 | ####### Object memory ####### | |
______________________________________________________________ |
[ Python's raw memory allocator (PyMem_ API) ] |
+1 | = 1; --i) {
if (*(q-i) != PYMEM_FORBIDDENBYTE) {
msg = "bad leading pad byte";
goto error;
}
}
nbytes = read_size_t(q - 2*SST);
tail = q + nbytes;
for (i = 0; i < SST; ++i) {
if (tail[i] != PYMEM_FORBIDDENBYTE) {
msg = "bad trailing pad byte";
goto error;
}
}
return;
error:
_PyObject_DebugDumpAddress(p);
Py_FatalError(msg);
}
/* Display info to stderr about the memory block at p. */
static void
_PyObject_DebugDumpAddress(const void *p)
{
const uint8_t *q = (const uint8_t *)p;
const uint8_t *tail;
size_t nbytes;
int i;
int ok;
char id;
fprintf(stderr, "Debug memory block at address p=%p:", p);
if (p == NULL) {
fprintf(stderr, "\n");
return;
}
id = (char)q[-SST];
fprintf(stderr, " API '%c'\n", id);
nbytes = read_size_t(q - 2*SST);
fprintf(stderr, " %" PY_FORMAT_SIZE_T "u bytes originally "
"requested\n", nbytes);
/* In case this is nuts, check the leading pad bytes first. */
fprintf(stderr, " The %d pad bytes at p-%d are ", SST-1, SST-1);
ok = 1;
for (i = 1; i = 1; --i) {
const uint8_t byte = *(q-i);
fprintf(stderr, " at p-%d: 0x%02x", i, byte);
if (byte != PYMEM_FORBIDDENBYTE)
fputs(" *** OUCH", stderr);
fputc('\n', stderr);
}
fputs(" Because memory is corrupted at the start, the "
"count of bytes requested\n"
" may be bogus, and checking the trailing pad "
"bytes may segfault.\n", stderr);
}
tail = q + nbytes;
fprintf(stderr, " The %d pad bytes at tail=%p are ", SST, (void *)tail);
ok = 1;
for (i = 0; i < SST; ++i) {
if (tail[i] != PYMEM_FORBIDDENBYTE) {
ok = 0;
break;
}
}
if (ok)
fputs("FORBIDDENBYTE, as expected.\n", stderr);
else {
fprintf(stderr, "not all FORBIDDENBYTE (0x%02x):\n",
PYMEM_FORBIDDENBYTE);
for (i = 0; i < SST; ++i) {
const uint8_t byte = tail[i];
fprintf(stderr, " at tail+%d: 0x%02x",
i, byte);
if (byte != PYMEM_FORBIDDENBYTE)
fputs(" *** OUCH", stderr);
fputc('\n', stderr);
}
}
#ifdef PYMEM_DEBUG_SERIALNO
size_t serial = read_size_t(tail + SST);
fprintf(stderr, " The block was made by call #%" PY_FORMAT_SIZE_T
"u to debug malloc/realloc.\n", serial);
#endif
if (nbytes > 0) {
i = 0;
fputs(" Data at p:", stderr);
/* print up to 8 bytes at the start */
while (q < tail && i < 8) {
fprintf(stderr, " %02x", *q);
++i;
++q;
}
/* and up to 8 at the end */
if (q < tail) {
if (tail - q > 8) {
fputs(" ...", stderr);
q = tail - 8;
}
while (q < tail) {
fprintf(stderr, " %02x", *q);
++q;
}
}
fputc('\n', stderr);
}
fputc('\n', stderr);
fflush(stderr);
_PyMem_DumpTraceback(fileno(stderr), p);
}
static size_t
printone(FILE *out, const char* msg, size_t value)
{
int i, k;
char buf[100];
size_t origvalue = value;
fputs(msg, out);
for (i = (int)strlen(msg); i < 35; ++i)
fputc(' ', out);
fputc('=', out);
/* Write the value with commas. */
i = 22;
buf[i--] = '\0';
buf[i--] = '\n';
k = 3;
do {
size_t nextvalue = value / 10;
unsigned int digit = (unsigned int)(value - nextvalue * 10);
value = nextvalue;
buf[i--] = (char)(digit + '0');
--k;
if (k == 0 && value && i >= 0) {
k = 3;
buf[i--] = ',';
}
} while (value && i >= 0);
while (i >= 0)
buf[i--] = ' ';
fputs(buf, out);
return origvalue;
}
void
_PyDebugAllocatorStats(FILE *out,
const char *block_name, int num_blocks, size_t sizeof_block)
{
char buf1[128];
char buf2[128];
PyOS_snprintf(buf1, sizeof(buf1),
"%d %ss * %" PY_FORMAT_SIZE_T "d bytes each",
num_blocks, block_name, sizeof_block);
PyOS_snprintf(buf2, sizeof(buf2),
"%48s ", buf1);
(void)printone(out, buf2, num_blocks * sizeof_block);
}
#ifdef WITH_PYMALLOC
#ifdef Py_DEBUG
/* Is target in the list? The list is traversed via the nextpool pointers.
* The list may be NULL-terminated, or circular. Return 1 if target is in
* list, else 0.
*/
static int
pool_is_in_list(const poolp target, poolp list)
{
poolp origlist = list;
assert(target != NULL);
if (list == NULL)
return 0;
do {
if (target == list)
return 1;
list = list->nextpool;
} while (list != NULL && list != origlist);
return 0;
}
#endif
/* Print summary info to "out" about the state of pymalloc's structures.
* In Py_DEBUG mode, also perform some expensive internal consistency
* checks.
*
* Return 0 if the memory debug hooks are not installed or no statistics was
* written into out, return 1 otherwise.
*/
int
_PyObject_DebugMallocStats(FILE *out)
{
if (!_PyMem_PymallocEnabled()) {
return 0;
}
uint i;
const uint numclasses = SMALL_REQUEST_THRESHOLD >> ALIGNMENT_SHIFT;
/* # of pools, allocated blocks, and free blocks per class index */
size_t numpools[SMALL_REQUEST_THRESHOLD >> ALIGNMENT_SHIFT];
size_t numblocks[SMALL_REQUEST_THRESHOLD >> ALIGNMENT_SHIFT];
size_t numfreeblocks[SMALL_REQUEST_THRESHOLD >> ALIGNMENT_SHIFT];
/* total # of allocated bytes in used and full pools */
size_t allocated_bytes = 0;
/* total # of available bytes in used pools */
size_t available_bytes = 0;
/* # of free pools + pools not yet carved out of current arena */
uint numfreepools = 0;
/* # of bytes for arena alignment padding */
size_t arena_alignment = 0;
/* # of bytes in used and full pools used for pool_headers */
size_t pool_header_bytes = 0;
/* # of bytes in used and full pools wasted due to quantization,
* i.e. the necessarily leftover space at the ends of used and
* full pools.
*/
size_t quantization = 0;
/* # of arenas actually allocated. */
size_t narenas = 0;
/* running total -- should equal narenas * ARENA_SIZE */
size_t total;
char buf[128];
fprintf(out, "Small block threshold = %d, in %u size classes.\n",
SMALL_REQUEST_THRESHOLD, numclasses);
for (i = 0; i < numclasses; ++i)
numpools[i] = numblocks[i] = numfreeblocks[i] = 0;
/* Because full pools aren't linked to from anything, it's easiest
* to march over all the arenas. If we're lucky, most of the memory
* will be living in full pools -- would be a shame to miss them.
*/
for (i = 0; i < maxarenas; ++i) {
uint j;
uintptr_t base = arenas[i].address;
/* Skip arenas which are not allocated. */
if (arenas[i].address == (uintptr_t)NULL)
continue;
narenas += 1;
numfreepools += arenas[i].nfreepools;
/* round up to pool alignment */
if (base & (uintptr_t)POOL_SIZE_MASK) {
arena_alignment += POOL_SIZE;
base &= ~(uintptr_t)POOL_SIZE_MASK;
base += POOL_SIZE;
}
/* visit every pool in the arena */
assert(base szidx;
uint freeblocks;
if (p->ref.count == 0) {
/* currently unused */
#ifdef Py_DEBUG
assert(pool_is_in_list(p, arenas[i].freepools));
#endif
continue;
}
++numpools[sz];
numblocks[sz] += p->ref.count;
freeblocks = NUMBLOCKS(sz) - p->ref.count;
numfreeblocks[sz] += freeblocks;
#ifdef Py_DEBUG
if (freeblocks > 0)
assert(pool_is_in_list(p, usedpools[sz + sz]));
#endif
}
}
assert(narenas == narenas_currently_allocated);
fputc('\n', out);
fputs("class size num pools blocks in use avail blocks\n"
"----- ---- --------- ------------- ------------\n",
out);
for (i = 0; i < numclasses; ++i) {
size_t p = numpools[i];
size_t b = numblocks[i];
size_t f = numfreeblocks[i];
uint size = INDEX2SIZE(i);
if (p == 0) {
assert(b == 0 && f == 0);
continue;
}
fprintf(out, "%5u %6u "
"%11" PY_FORMAT_SIZE_T "u "
"%15" PY_FORMAT_SIZE_T "u "
"%13" PY_FORMAT_SIZE_T "u\n",
i, size, p, b, f);
allocated_bytes += b * size;
available_bytes += f * size;
pool_header_bytes += p * POOL_OVERHEAD;
quantization += p * ((POOL_SIZE - POOL_OVERHEAD) % size);
}
fputc('\n', out);
#ifdef PYMEM_DEBUG_SERIALNO
if (_PyMem_DebugEnabled()) {
(void)printone(out, "# times object malloc called", serialno);
}
#endif
(void)printone(out, "# arenas allocated total", ntimes_arena_allocated);
(void)printone(out, "# arenas reclaimed", ntimes_arena_allocated - narenas);
(void)printone(out, "# arenas highwater mark", narenas_highwater);
(void)printone(out, "# arenas allocated current", narenas);
PyOS_snprintf(buf, sizeof(buf),
"%" PY_FORMAT_SIZE_T "u arenas * %d bytes/arena",
narenas, ARENA_SIZE);
(void)printone(out, buf, narenas * ARENA_SIZE);
fputc('\n', out);
total = printone(out, "# bytes in allocated blocks", allocated_bytes);
total += printone(out, "# bytes in available blocks", available_bytes);
PyOS_snprintf(buf, sizeof(buf),
"%u unused pools * %d bytes", numfreepools, POOL_SIZE);
total += printone(out, buf, (size_t)numfreepools * POOL_SIZE);
total += printone(out, "# bytes lost to pool headers", pool_header_bytes);
total += printone(out, "# bytes lost to quantization", quantization);
total += printone(out, "# bytes lost to arena alignment", arena_alignment);
(void)printone(out, "Total", total);
return 1;
}
#endif /* #ifdef WITH_PYMALLOC */