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Code Issues Releases Activity
91f4908798
cpython/Objects/obmalloc.c
Sam Gross 2d9d3a9f53
gh-122697: Fix free-threading memory leaks at shutdown (#122703) 
We were not properly accounting for interpreter memory leaks at
shutdown and had two sources of leaks:

 * Objects that use deferred reference counting and were reachable via
   static types outlive the final GC. We now disable deferred reference
   counting on all objects if we are calling the GC due to interpreter
   shutdown.

 * `_PyMem_FreeDelayed` did not properly check for interpreter shutdown
   so we had some memory blocks that were enqueued to be freed, but
   never actually freed.

 * `_PyType_FinalizeIdPool` wasn't called at interpreter shutdown.
2024-08-08 12:48:17 -04:00

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/* Python's malloc wrappers (see pymem.h) */
#include "Python.h"
#include "pycore_code.h" // stats
#include "pycore_object.h" // _PyDebugAllocatorStats() definition
#include "pycore_obmalloc.h"
#include "pycore_pyerrors.h" // _Py_FatalErrorFormat()
#include "pycore_pymem.h"
#include "pycore_pystate.h" // _PyInterpreterState_GET
#include "pycore_obmalloc_init.h"
#include <stdlib.h> // malloc()
#include <stdbool.h>
#ifdef WITH_MIMALLOC
// Forward declarations of functions used in our mimalloc modifications
static void _PyMem_mi_page_clear_qsbr(mi_page_t *page);
static bool _PyMem_mi_page_is_safe_to_free(mi_page_t *page);
static bool _PyMem_mi_page_maybe_free(mi_page_t *page, mi_page_queue_t *pq, bool force);
static void _PyMem_mi_page_reclaimed(mi_page_t *page);
static void _PyMem_mi_heap_collect_qsbr(mi_heap_t *heap);
# include "pycore_mimalloc.h"
# include "mimalloc/static.c"
# include "mimalloc/internal.h" // for stats
#endif
#if defined(Py_GIL_DISABLED) && !defined(WITH_MIMALLOC)
# error "Py_GIL_DISABLED requires WITH_MIMALLOC"
#endif
#undef uint
#define uint pymem_uint
/* Defined in tracemalloc.c */
extern void _PyMem_DumpTraceback(int fd, const void *ptr);
static void _PyObject_DebugDumpAddress(const void *p);
static void _PyMem_DebugCheckAddress(const char *func, char api_id, const void *p);
static void set_up_debug_hooks_domain_unlocked(PyMemAllocatorDomain domain);
static void set_up_debug_hooks_unlocked(void);
static void get_allocator_unlocked(PyMemAllocatorDomain, PyMemAllocatorEx *);
static void set_allocator_unlocked(PyMemAllocatorDomain, PyMemAllocatorEx *);
/***************************************/
/* low-level allocator implementations */
/***************************************/
/* the default raw allocator (wraps malloc) */
void *
_PyMem_RawMalloc(void *Py_UNUSED(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);
}
void *
_PyMem_RawCalloc(void *Py_UNUSED(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);
}
void *
_PyMem_RawRealloc(void *Py_UNUSED(ctx), void *ptr, size_t size)
{
if (size == 0)
size = 1;
return realloc(ptr, size);
}
void
_PyMem_RawFree(void *Py_UNUSED(ctx), void *ptr)
{
free(ptr);
}
#ifdef WITH_MIMALLOC
static void
_PyMem_mi_page_clear_qsbr(mi_page_t *page)
{
#ifdef Py_GIL_DISABLED
// Clear the QSBR goal and remove the page from the QSBR linked list.
page->qsbr_goal = 0;
if (page->qsbr_node.next != NULL) {
llist_remove(&page->qsbr_node);
}
#endif
}
// Check if an empty, newly reclaimed page is safe to free now.
static bool
_PyMem_mi_page_is_safe_to_free(mi_page_t *page)
{
assert(mi_page_all_free(page));
#ifdef Py_GIL_DISABLED
assert(page->qsbr_node.next == NULL);
if (page->use_qsbr && page->qsbr_goal != 0) {
_PyThreadStateImpl *tstate = (_PyThreadStateImpl *)_PyThreadState_GET();
if (tstate == NULL) {
return false;
}
return _Py_qbsr_goal_reached(tstate->qsbr, page->qsbr_goal);
}
#endif
return true;
}
static bool
_PyMem_mi_page_maybe_free(mi_page_t *page, mi_page_queue_t *pq, bool force)
{
#ifdef Py_GIL_DISABLED
assert(mi_page_all_free(page));
if (page->use_qsbr) {
_PyThreadStateImpl *tstate = (_PyThreadStateImpl *)PyThreadState_GET();
if (page->qsbr_goal != 0 && _Py_qbsr_goal_reached(tstate->qsbr, page->qsbr_goal)) {
_PyMem_mi_page_clear_qsbr(page);
_mi_page_free(page, pq, force);
return true;
}
_PyMem_mi_page_clear_qsbr(page);
page->retire_expire = 0;
page->qsbr_goal = _Py_qsbr_deferred_advance(tstate->qsbr);
llist_insert_tail(&tstate->mimalloc.page_list, &page->qsbr_node);
return false;
}
#endif
_mi_page_free(page, pq, force);
return true;
}
static void
_PyMem_mi_page_reclaimed(mi_page_t *page)
{
#ifdef Py_GIL_DISABLED
assert(page->qsbr_node.next == NULL);
if (page->qsbr_goal != 0) {
if (mi_page_all_free(page)) {
assert(page->qsbr_node.next == NULL);
_PyThreadStateImpl *tstate = (_PyThreadStateImpl *)PyThreadState_GET();
page->retire_expire = 0;
llist_insert_tail(&tstate->mimalloc.page_list, &page->qsbr_node);
}
else {
page->qsbr_goal = 0;
}
}
#endif
}
static void
_PyMem_mi_heap_collect_qsbr(mi_heap_t *heap)
{
#ifdef Py_GIL_DISABLED
if (!heap->page_use_qsbr) {
return;
}
_PyThreadStateImpl *tstate = (_PyThreadStateImpl *)_PyThreadState_GET();
struct llist_node *head = &tstate->mimalloc.page_list;
if (llist_empty(head)) {
return;
}
struct llist_node *node;
llist_for_each_safe(node, head) {
mi_page_t *page = llist_data(node, mi_page_t, qsbr_node);
if (!mi_page_all_free(page)) {
// We allocated from this page some point after the delayed free
_PyMem_mi_page_clear_qsbr(page);
continue;
}
if (!_Py_qsbr_poll(tstate->qsbr, page->qsbr_goal)) {
return;
}
_PyMem_mi_page_clear_qsbr(page);
_mi_page_free(page, mi_page_queue_of(page), false);
}
#endif
}
void *
_PyMem_MiMalloc(void *ctx, size_t size)
{
#ifdef Py_GIL_DISABLED
_PyThreadStateImpl *tstate = (_PyThreadStateImpl *)_PyThreadState_GET();
mi_heap_t *heap = &tstate->mimalloc.heaps[_Py_MIMALLOC_HEAP_MEM];
return mi_heap_malloc(heap, size);
#else
return mi_malloc(size);
#endif
}
void *
_PyMem_MiCalloc(void *ctx, size_t nelem, size_t elsize)
{
#ifdef Py_GIL_DISABLED
_PyThreadStateImpl *tstate = (_PyThreadStateImpl *)_PyThreadState_GET();
mi_heap_t *heap = &tstate->mimalloc.heaps[_Py_MIMALLOC_HEAP_MEM];
return mi_heap_calloc(heap, nelem, elsize);
#else
return mi_calloc(nelem, elsize);
#endif
}
void *
_PyMem_MiRealloc(void *ctx, void *ptr, size_t size)
{
#ifdef Py_GIL_DISABLED
_PyThreadStateImpl *tstate = (_PyThreadStateImpl *)_PyThreadState_GET();
mi_heap_t *heap = &tstate->mimalloc.heaps[_Py_MIMALLOC_HEAP_MEM];
return mi_heap_realloc(heap, ptr, size);
#else
return mi_realloc(ptr, size);
#endif
}
void
_PyMem_MiFree(void *ctx, void *ptr)
{
mi_free(ptr);
}
void *
_PyObject_MiMalloc(void *ctx, size_t nbytes)
{
#ifdef Py_GIL_DISABLED
_PyThreadStateImpl *tstate = (_PyThreadStateImpl *)_PyThreadState_GET();
mi_heap_t *heap = tstate->mimalloc.current_object_heap;
return mi_heap_malloc(heap, nbytes);
#else
return mi_malloc(nbytes);
#endif
}
void *
_PyObject_MiCalloc(void *ctx, size_t nelem, size_t elsize)
{
#ifdef Py_GIL_DISABLED
_PyThreadStateImpl *tstate = (_PyThreadStateImpl *)_PyThreadState_GET();
mi_heap_t *heap = tstate->mimalloc.current_object_heap;
return mi_heap_calloc(heap, nelem, elsize);
#else
return mi_calloc(nelem, elsize);
#endif
}
void *
_PyObject_MiRealloc(void *ctx, void *ptr, size_t nbytes)
{
#ifdef Py_GIL_DISABLED
_PyThreadStateImpl *tstate = (_PyThreadStateImpl *)_PyThreadState_GET();
mi_heap_t *heap = tstate->mimalloc.current_object_heap;
return mi_heap_realloc(heap, ptr, nbytes);
#else
return mi_realloc(ptr, nbytes);
#endif
}
void
_PyObject_MiFree(void *ctx, void *ptr)
{
mi_free(ptr);
}
#endif // WITH_MIMALLOC
#define MALLOC_ALLOC {NULL, _PyMem_RawMalloc, _PyMem_RawCalloc, _PyMem_RawRealloc, _PyMem_RawFree}
#ifdef WITH_MIMALLOC
# define MIMALLOC_ALLOC {NULL, _PyMem_MiMalloc, _PyMem_MiCalloc, _PyMem_MiRealloc, _PyMem_MiFree}
# define MIMALLOC_OBJALLOC {NULL, _PyObject_MiMalloc, _PyObject_MiCalloc, _PyObject_MiRealloc, _PyObject_MiFree}
#endif
/* the pymalloc allocator */
// The actual implementation is further down.
#if defined(WITH_PYMALLOC)
void* _PyObject_Malloc(void *ctx, size_t size);
void* _PyObject_Calloc(void *ctx, size_t nelem, size_t elsize);
void _PyObject_Free(void *ctx, void *p);
void* _PyObject_Realloc(void *ctx, void *ptr, size_t size);
# define PYMALLOC_ALLOC {NULL, _PyObject_Malloc, _PyObject_Calloc, _PyObject_Realloc, _PyObject_Free}
#endif // WITH_PYMALLOC
#if defined(Py_GIL_DISABLED)
// Py_GIL_DISABLED requires using mimalloc for "mem" and "obj" domains.
# define PYRAW_ALLOC MALLOC_ALLOC
# define PYMEM_ALLOC MIMALLOC_ALLOC
# define PYOBJ_ALLOC MIMALLOC_OBJALLOC
#elif defined(WITH_PYMALLOC)
# define PYRAW_ALLOC MALLOC_ALLOC
# define PYMEM_ALLOC PYMALLOC_ALLOC
# define PYOBJ_ALLOC PYMALLOC_ALLOC
#else
# define PYRAW_ALLOC MALLOC_ALLOC
# define PYMEM_ALLOC MALLOC_ALLOC
# define PYOBJ_ALLOC MALLOC_ALLOC
#endif
/* the default debug allocators */
// The actual implementation is further down.
void* _PyMem_DebugRawMalloc(void *ctx, size_t size);
void* _PyMem_DebugRawCalloc(void *ctx, size_t nelem, size_t elsize);
void* _PyMem_DebugRawRealloc(void *ctx, void *ptr, size_t size);
void _PyMem_DebugRawFree(void *ctx, void *ptr);
void* _PyMem_DebugMalloc(void *ctx, size_t size);
void* _PyMem_DebugCalloc(void *ctx, size_t nelem, size_t elsize);
void* _PyMem_DebugRealloc(void *ctx, void *ptr, size_t size);
void _PyMem_DebugFree(void *ctx, void *p);
#define PYDBGRAW_ALLOC \
{&_PyRuntime.allocators.debug.raw, _PyMem_DebugRawMalloc, _PyMem_DebugRawCalloc, _PyMem_DebugRawRealloc, _PyMem_DebugRawFree}
#define PYDBGMEM_ALLOC \
{&_PyRuntime.allocators.debug.mem, _PyMem_DebugMalloc, _PyMem_DebugCalloc, _PyMem_DebugRealloc, _PyMem_DebugFree}
#define PYDBGOBJ_ALLOC \
{&_PyRuntime.allocators.debug.obj, _PyMem_DebugMalloc, _PyMem_DebugCalloc, _PyMem_DebugRealloc, _PyMem_DebugFree}
/* the low-level virtual memory allocator */
#ifdef WITH_PYMALLOC
# ifdef MS_WINDOWS
# include <windows.h>
# elif defined(HAVE_MMAP)
# include <sys/mman.h>
# ifdef MAP_ANONYMOUS
# define ARENAS_USE_MMAP
# endif
# endif
#endif
void *
_PyMem_ArenaAlloc(void *Py_UNUSED(ctx), size_t size)
{
#ifdef MS_WINDOWS
return VirtualAlloc(NULL, size,
MEM_COMMIT | MEM_RESERVE, PAGE_READWRITE);
#elif defined(ARENAS_USE_MMAP)
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;
#else
return malloc(size);
#endif
}
void
_PyMem_ArenaFree(void *Py_UNUSED(ctx), void *ptr,
#if defined(ARENAS_USE_MMAP)
size_t size
#else
size_t Py_UNUSED(size)
#endif
)
{
#ifdef MS_WINDOWS
/* Unlike free(), VirtualFree() does not special-case NULL to noop. */
if (ptr == NULL) {
return;
}
VirtualFree(ptr, 0, MEM_RELEASE);
#elif defined(ARENAS_USE_MMAP)
/* Unlike free(), munmap() does not special-case NULL to noop. */
if (ptr == NULL) {
return;
}
munmap(ptr, size);
#else
free(ptr);
#endif
}
/*******************************************/
/* end low-level allocator implementations */
/*******************************************/
#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
#define ALLOCATORS_MUTEX (_PyRuntime.allocators.mutex)
#define _PyMem_Raw (_PyRuntime.allocators.standard.raw)
#define _PyMem (_PyRuntime.allocators.standard.mem)
#define _PyObject (_PyRuntime.allocators.standard.obj)
#define _PyMem_Debug (_PyRuntime.allocators.debug)
#define _PyObject_Arena (_PyRuntime.allocators.obj_arena)
/***************************/
/* managing the allocators */
/***************************/
static int
set_default_allocator_unlocked(PyMemAllocatorDomain domain, int debug,
PyMemAllocatorEx *old_alloc)
{
if (old_alloc != NULL) {
get_allocator_unlocked(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;
}
set_allocator_unlocked(domain, &new_alloc);
if (debug) {
set_up_debug_hooks_domain_unlocked(domain);
}
return 0;
}
#ifdef Py_DEBUG
static const int pydebug = 1;
#else
static const int pydebug = 0;
#endif
int
_PyMem_SetDefaultAllocator(PyMemAllocatorDomain domain,
PyMemAllocatorEx *old_alloc)
{
PyMutex_Lock(&ALLOCATORS_MUTEX);
int res = set_default_allocator_unlocked(domain, pydebug, old_alloc);
PyMutex_Unlock(&ALLOCATORS_MUTEX);
return res;
}
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;
}
#if defined(WITH_PYMALLOC) && !defined(Py_GIL_DISABLED)
else if (strcmp(name, "pymalloc") == 0) {
*allocator = PYMEM_ALLOCATOR_PYMALLOC;
}
else if (strcmp(name, "pymalloc_debug") == 0) {
*allocator = PYMEM_ALLOCATOR_PYMALLOC_DEBUG;
}
#endif
#ifdef WITH_MIMALLOC
else if (strcmp(name, "mimalloc") == 0) {
*allocator = PYMEM_ALLOCATOR_MIMALLOC;
}
else if (strcmp(name, "mimalloc_debug") == 0) {
*allocator = PYMEM_ALLOCATOR_MIMALLOC_DEBUG;
}
#endif
#ifndef Py_GIL_DISABLED
else if (strcmp(name, "malloc") == 0) {
*allocator = PYMEM_ALLOCATOR_MALLOC;
}
else if (strcmp(name, "malloc_debug") == 0) {
*allocator = PYMEM_ALLOCATOR_MALLOC_DEBUG;
}
#endif
else {
/* unknown allocator */
return -1;
}
return 0;
}
static int
set_up_allocators_unlocked(PyMemAllocatorName allocator)
{
switch (allocator) {
case PYMEM_ALLOCATOR_NOT_SET:
/* do nothing */
break;
case PYMEM_ALLOCATOR_DEFAULT:
(void)set_default_allocator_unlocked(PYMEM_DOMAIN_RAW, pydebug, NULL);
(void)set_default_allocator_unlocked(PYMEM_DOMAIN_MEM, pydebug, NULL);
(void)set_default_allocator_unlocked(PYMEM_DOMAIN_OBJ, pydebug, NULL);
_PyRuntime.allocators.is_debug_enabled = pydebug;
break;
case PYMEM_ALLOCATOR_DEBUG:
(void)set_default_allocator_unlocked(PYMEM_DOMAIN_RAW, 1, NULL);
(void)set_default_allocator_unlocked(PYMEM_DOMAIN_MEM, 1, NULL);
(void)set_default_allocator_unlocked(PYMEM_DOMAIN_OBJ, 1, NULL);
_PyRuntime.allocators.is_debug_enabled = 1;
break;
#ifdef WITH_PYMALLOC
case PYMEM_ALLOCATOR_PYMALLOC:
case PYMEM_ALLOCATOR_PYMALLOC_DEBUG:
{
PyMemAllocatorEx malloc_alloc = MALLOC_ALLOC;
set_allocator_unlocked(PYMEM_DOMAIN_RAW, &malloc_alloc);
PyMemAllocatorEx pymalloc = PYMALLOC_ALLOC;
set_allocator_unlocked(PYMEM_DOMAIN_MEM, &pymalloc);
set_allocator_unlocked(PYMEM_DOMAIN_OBJ, &pymalloc);
int is_debug = (allocator == PYMEM_ALLOCATOR_PYMALLOC_DEBUG);
_PyRuntime.allocators.is_debug_enabled = is_debug;
if (is_debug) {
set_up_debug_hooks_unlocked();
}
break;
}
#endif
#ifdef WITH_MIMALLOC
case PYMEM_ALLOCATOR_MIMALLOC:
case PYMEM_ALLOCATOR_MIMALLOC_DEBUG:
{
PyMemAllocatorEx malloc_alloc = MALLOC_ALLOC;
set_allocator_unlocked(PYMEM_DOMAIN_RAW, &malloc_alloc);
PyMemAllocatorEx pymalloc = MIMALLOC_ALLOC;
set_allocator_unlocked(PYMEM_DOMAIN_MEM, &pymalloc);
PyMemAllocatorEx objmalloc = MIMALLOC_OBJALLOC;
set_allocator_unlocked(PYMEM_DOMAIN_OBJ, &objmalloc);
int is_debug = (allocator == PYMEM_ALLOCATOR_MIMALLOC_DEBUG);
_PyRuntime.allocators.is_debug_enabled = is_debug;
if (is_debug) {
set_up_debug_hooks_unlocked();
}
break;
}
#endif
case PYMEM_ALLOCATOR_MALLOC:
case PYMEM_ALLOCATOR_MALLOC_DEBUG:
{
PyMemAllocatorEx malloc_alloc = MALLOC_ALLOC;
set_allocator_unlocked(PYMEM_DOMAIN_RAW, &malloc_alloc);
set_allocator_unlocked(PYMEM_DOMAIN_MEM, &malloc_alloc);
set_allocator_unlocked(PYMEM_DOMAIN_OBJ, &malloc_alloc);
int is_debug = (allocator == PYMEM_ALLOCATOR_MALLOC_DEBUG);
_PyRuntime.allocators.is_debug_enabled = is_debug;
if (is_debug) {
set_up_debug_hooks_unlocked();
}
break;
}
default:
/* unknown allocator */
return -1;
}
return 0;
}
int
_PyMem_SetupAllocators(PyMemAllocatorName allocator)
{
PyMutex_Lock(&ALLOCATORS_MUTEX);
int res = set_up_allocators_unlocked(allocator);
PyMutex_Unlock(&ALLOCATORS_MUTEX);
return res;
}
static int
pymemallocator_eq(PyMemAllocatorEx *a, PyMemAllocatorEx *b)
{
return (memcmp(a, b, sizeof(PyMemAllocatorEx)) == 0);
}
static const char*
get_current_allocator_name_unlocked(void)
{
PyMemAllocatorEx malloc_alloc = MALLOC_ALLOC;
#ifdef WITH_PYMALLOC
PyMemAllocatorEx pymalloc = PYMALLOC_ALLOC;
#endif
#ifdef WITH_MIMALLOC
PyMemAllocatorEx mimalloc = MIMALLOC_ALLOC;
PyMemAllocatorEx mimalloc_obj = MIMALLOC_OBJALLOC;
#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
#ifdef WITH_MIMALLOC
if (pymemallocator_eq(&_PyMem_Raw, &malloc_alloc) &&
pymemallocator_eq(&_PyMem, &mimalloc) &&
pymemallocator_eq(&_PyObject, &mimalloc_obj))
{
return "mimalloc";
}
#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
#ifdef WITH_MIMALLOC
if (pymemallocator_eq(&_PyMem_Debug.raw.alloc, &malloc_alloc) &&
pymemallocator_eq(&_PyMem_Debug.mem.alloc, &mimalloc) &&
pymemallocator_eq(&_PyMem_Debug.obj.alloc, &mimalloc_obj))
{
return "mimalloc_debug";
}
#endif
}
return NULL;
}
const char*
_PyMem_GetCurrentAllocatorName(void)
{
PyMutex_Lock(&ALLOCATORS_MUTEX);
const char *name = get_current_allocator_name_unlocked();
PyMutex_Unlock(&ALLOCATORS_MUTEX);
return name;
}
int
_PyMem_DebugEnabled(void)
{
return _PyRuntime.allocators.is_debug_enabled;
}
#ifdef WITH_PYMALLOC
static int
_PyMem_PymallocEnabled(void)
{
if (_PyMem_DebugEnabled()) {
return (_PyMem_Debug.obj.alloc.malloc == _PyObject_Malloc);
}
else {
return (_PyObject.malloc == _PyObject_Malloc);
}
}
#ifdef WITH_MIMALLOC
static int
_PyMem_MimallocEnabled(void)
{
#ifdef Py_GIL_DISABLED
return 1;
#else
if (_PyMem_DebugEnabled()) {
return (_PyMem_Debug.obj.alloc.malloc == _PyObject_MiMalloc);
}
else {
return (_PyObject.malloc == _PyObject_MiMalloc);
}
#endif
}
#endif // WITH_MIMALLOC
#endif // WITH_PYMALLOC
static void
set_up_debug_hooks_domain_unlocked(PyMemAllocatorDomain domain)
{
PyMemAllocatorEx alloc;
if (domain == PYMEM_DOMAIN_RAW) {
if (_PyMem_Raw.malloc == _PyMem_DebugRawMalloc) {
return;
}
get_allocator_unlocked(domain, &_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;
set_allocator_unlocked(domain, &alloc);
}
else if (domain == PYMEM_DOMAIN_MEM) {
if (_PyMem.malloc == _PyMem_DebugMalloc) {
return;
}
get_allocator_unlocked(domain, &_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;
set_allocator_unlocked(domain, &alloc);
}
else if (domain == PYMEM_DOMAIN_OBJ) {
if (_PyObject.malloc == _PyMem_DebugMalloc) {
return;
}
get_allocator_unlocked(domain, &_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;
set_allocator_unlocked(domain, &alloc);
}
}
static void
set_up_debug_hooks_unlocked(void)
{
set_up_debug_hooks_domain_unlocked(PYMEM_DOMAIN_RAW);
set_up_debug_hooks_domain_unlocked(PYMEM_DOMAIN_MEM);
set_up_debug_hooks_domain_unlocked(PYMEM_DOMAIN_OBJ);
_PyRuntime.allocators.is_debug_enabled = 1;
}
void
PyMem_SetupDebugHooks(void)
{
PyMutex_Lock(&ALLOCATORS_MUTEX);
set_up_debug_hooks_unlocked();
PyMutex_Unlock(&ALLOCATORS_MUTEX);
}
static void
get_allocator_unlocked(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;
}
}
static void
set_allocator_unlocked(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
PyMem_GetAllocator(PyMemAllocatorDomain domain, PyMemAllocatorEx *allocator)
{
PyMutex_Lock(&ALLOCATORS_MUTEX);
get_allocator_unlocked(domain, allocator);
PyMutex_Unlock(&ALLOCATORS_MUTEX);
}
void
PyMem_SetAllocator(PyMemAllocatorDomain domain, PyMemAllocatorEx *allocator)
{
PyMutex_Lock(&ALLOCATORS_MUTEX);
set_allocator_unlocked(domain, allocator);
PyMutex_Unlock(&ALLOCATORS_MUTEX);
}
void
PyObject_GetArenaAllocator(PyObjectArenaAllocator *allocator)
{
PyMutex_Lock(&ALLOCATORS_MUTEX);
*allocator = _PyObject_Arena;
PyMutex_Unlock(&ALLOCATORS_MUTEX);
}
void
PyObject_SetArenaAllocator(PyObjectArenaAllocator *allocator)
{
PyMutex_Lock(&ALLOCATORS_MUTEX);
_PyObject_Arena = *allocator;
PyMutex_Unlock(&ALLOCATORS_MUTEX);
}
/* Note that there is a possible, but very unlikely, race in any place
* below where we call one of the allocator functions. We access two
* fields in each case: "malloc", etc. and "ctx".
*
* It is unlikely that the allocator will be changed while one of those
* calls is happening, much less in that very narrow window.
* Furthermore, the likelihood of a race is drastically reduced by the
* fact that the allocator may not be changed after runtime init
* (except with a wrapper).
*
* With the above in mind, we currently don't worry about locking
* around these uses of the runtime-global allocators state. */
/*************************/
/* the "arena" allocator */
/*************************/
void *
_PyObject_VirtualAlloc(size_t size)
{
return _PyObject_Arena.alloc(_PyObject_Arena.ctx, size);
}
void
_PyObject_VirtualFree(void *obj, size_t size)
{
_PyObject_Arena.free(_PyObject_Arena.ctx, obj, size);
}
/***********************/
/* the "raw" 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);
}
/***********************/
/* the "mem" allocator */
/***********************/
void *
PyMem_Malloc(size_t size)
{
/* see PyMem_RawMalloc() */
if (size > (size_t)PY_SSIZE_T_MAX)
return NULL;
OBJECT_STAT_INC_COND(allocations512, size < 512);
OBJECT_STAT_INC_COND(allocations4k, size >= 512 && size < 4094);
OBJECT_STAT_INC_COND(allocations_big, size >= 4094);
OBJECT_STAT_INC(allocations);
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;
OBJECT_STAT_INC_COND(allocations512, elsize < 512);
OBJECT_STAT_INC_COND(allocations4k, elsize >= 512 && elsize < 4094);
OBJECT_STAT_INC_COND(allocations_big, elsize >= 4094);
OBJECT_STAT_INC(allocations);
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)
{
OBJECT_STAT_INC(frees);
_PyMem.free(_PyMem.ctx, ptr);
}
/***************************/
/* pymem utility functions */
/***************************/
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;
}
/***********************************************/
/* Delayed freeing support for Py_GIL_DISABLED */
/***********************************************/
// So that sizeof(struct _mem_work_chunk) is 4096 bytes on 64-bit platforms.
#define WORK_ITEMS_PER_CHUNK 254
// A pointer to be freed once the QSBR read sequence reaches qsbr_goal.
struct _mem_work_item {
uintptr_t ptr; // lowest bit tagged 1 for objects freed with PyObject_Free
uint64_t qsbr_goal;
};
// A fixed-size buffer of pointers to be freed
struct _mem_work_chunk {
// Linked list node of chunks in queue
struct llist_node node;
Py_ssize_t rd_idx; // index of next item to read
Py_ssize_t wr_idx; // index of next item to write
struct _mem_work_item array[WORK_ITEMS_PER_CHUNK];
};
static void
free_work_item(uintptr_t ptr)
{
if (ptr & 0x01) {
PyObject_Free((char *)(ptr - 1));
}
else {
PyMem_Free((void *)ptr);
}
}
static void
free_delayed(uintptr_t ptr)
{
#ifndef Py_GIL_DISABLED
free_work_item(ptr);
#else
PyInterpreterState *interp = _PyInterpreterState_GET();
if (_PyInterpreterState_GetFinalizing(interp) != NULL ||
interp->stoptheworld.world_stopped)
{
// Free immediately during interpreter shutdown or if the world is
// stopped.
free_work_item(ptr);
return;
}
_PyThreadStateImpl *tstate = (_PyThreadStateImpl *)_PyThreadState_GET();
struct llist_node *head = &tstate->mem_free_queue;
struct _mem_work_chunk *buf = NULL;
if (!llist_empty(head)) {
// Try to re-use the last buffer
buf = llist_data(head->prev, struct _mem_work_chunk, node);
if (buf->wr_idx == WORK_ITEMS_PER_CHUNK) {
// already full
buf = NULL;
}
}
if (buf == NULL) {
buf = PyMem_Calloc(1, sizeof(*buf));
if (buf != NULL) {
llist_insert_tail(head, &buf->node);
}
}
if (buf == NULL) {
// failed to allocate a buffer, free immediately
_PyEval_StopTheWorld(tstate->base.interp);
free_work_item(ptr);
_PyEval_StartTheWorld(tstate->base.interp);
return;
}
assert(buf != NULL && buf->wr_idx < WORK_ITEMS_PER_CHUNK);
uint64_t seq = _Py_qsbr_deferred_advance(tstate->qsbr);
buf->array[buf->wr_idx].ptr = ptr;
buf->array[buf->wr_idx].qsbr_goal = seq;
buf->wr_idx++;
if (buf->wr_idx == WORK_ITEMS_PER_CHUNK) {
_PyMem_ProcessDelayed((PyThreadState *)tstate);
}
#endif
}
void
_PyMem_FreeDelayed(void *ptr)
{
assert(!((uintptr_t)ptr & 0x01));
free_delayed((uintptr_t)ptr);
}
void
_PyObject_FreeDelayed(void *ptr)
{
assert(!((uintptr_t)ptr & 0x01));
free_delayed(((uintptr_t)ptr)|0x01);
}
static struct _mem_work_chunk *
work_queue_first(struct llist_node *head)
{
return llist_data(head->next, struct _mem_work_chunk, node);
}
static void
process_queue(struct llist_node *head, struct _qsbr_thread_state *qsbr,
bool keep_empty)
{
while (!llist_empty(head)) {
struct _mem_work_chunk *buf = work_queue_first(head);
while (buf->rd_idx < buf->wr_idx) {
struct _mem_work_item *item = &buf->array[buf->rd_idx];
if (!_Py_qsbr_poll(qsbr, item->qsbr_goal)) {
return;
}
free_work_item(item->ptr);
buf->rd_idx++;
}
assert(buf->rd_idx == buf->wr_idx);
if (keep_empty && buf->node.next == head) {
// Keep the last buffer in the queue to reduce re-allocations
buf->rd_idx = buf->wr_idx = 0;
return;
}
llist_remove(&buf->node);
PyMem_Free(buf);
}
}
static void
process_interp_queue(struct _Py_mem_interp_free_queue *queue,
struct _qsbr_thread_state *qsbr)
{
if (!_Py_atomic_load_int_relaxed(&queue->has_work)) {
return;
}
// Try to acquire the lock, but don't block if it's already held.
if (_PyMutex_LockTimed(&queue->mutex, 0, 0) == PY_LOCK_ACQUIRED) {
process_queue(&queue->head, qsbr, false);
int more_work = !llist_empty(&queue->head);
_Py_atomic_store_int_relaxed(&queue->has_work, more_work);
PyMutex_Unlock(&queue->mutex);
}
}
void
_PyMem_ProcessDelayed(PyThreadState *tstate)
{
PyInterpreterState *interp = tstate->interp;
_PyThreadStateImpl *tstate_impl = (_PyThreadStateImpl *)tstate;
// Process thread-local work
process_queue(&tstate_impl->mem_free_queue, tstate_impl->qsbr, true);
// Process shared interpreter work
process_interp_queue(&interp->mem_free_queue, tstate_impl->qsbr);
}
void
_PyMem_AbandonDelayed(PyThreadState *tstate)
{
PyInterpreterState *interp = tstate->interp;
struct llist_node *queue = &((_PyThreadStateImpl *)tstate)->mem_free_queue;
if (llist_empty(queue)) {
return;
}
// Check if the queue contains one empty buffer
struct _mem_work_chunk *buf = work_queue_first(queue);
if (buf->rd_idx == buf->wr_idx) {
llist_remove(&buf->node);
PyMem_Free(buf);
assert(llist_empty(queue));
return;
}
// Merge the thread's work queue into the interpreter's work queue.
PyMutex_Lock(&interp->mem_free_queue.mutex);
llist_concat(&interp->mem_free_queue.head, queue);
_Py_atomic_store_int_relaxed(&interp->mem_free_queue.has_work, 1);
PyMutex_Unlock(&interp->mem_free_queue.mutex);
assert(llist_empty(queue)); // the thread's queue is now empty
}
void
_PyMem_FiniDelayed(PyInterpreterState *interp)
{
struct llist_node *head = &interp->mem_free_queue.head;
while (!llist_empty(head)) {
struct _mem_work_chunk *buf = work_queue_first(head);
while (buf->rd_idx < buf->wr_idx) {
// Free the remaining items immediately. There should be no other
// threads accessing the memory at this point during shutdown.
struct _mem_work_item *item = &buf->array[buf->rd_idx];
free_work_item(item->ptr);
buf->rd_idx++;
}
llist_remove(&buf->node);
PyMem_Free(buf);
}
}
/**************************/
/* the "object" allocator */
/**************************/
void *
PyObject_Malloc(size_t size)
{
/* see PyMem_RawMalloc() */
if (size > (size_t)PY_SSIZE_T_MAX)
return NULL;
OBJECT_STAT_INC_COND(allocations512, size < 512);
OBJECT_STAT_INC_COND(allocations4k, size >= 512 && size < 4094);
OBJECT_STAT_INC_COND(allocations_big, size >= 4094);
OBJECT_STAT_INC(allocations);
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;
OBJECT_STAT_INC_COND(allocations512, elsize < 512);
OBJECT_STAT_INC_COND(allocations4k, elsize >= 512 && elsize < 4094);
OBJECT_STAT_INC_COND(allocations_big, elsize >= 4094);
OBJECT_STAT_INC(allocations);
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)
{
OBJECT_STAT_INC(frees);
_PyObject.free(_PyObject.ctx, ptr);
}
/* 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)
# define LIKELY(value) __builtin_expect((value), 1)
#else
# define UNLIKELY(value) (value)
# define LIKELY(value) (value)
#endif
#ifdef WITH_PYMALLOC
#ifdef WITH_VALGRIND
#include <valgrind/valgrind.h>
/* -1 indicates that we haven't checked that we're running on valgrind yet. */
static int running_on_valgrind = -1;
#endif
typedef struct _obmalloc_state OMState;
/* obmalloc state for main interpreter and shared by all interpreters without
* their own obmalloc state. By not explicitly initializing this structure, it
* will be allocated in the BSS which is a small performance win. The radix
* tree arrays are fairly large but are sparsely used. */
static struct _obmalloc_state obmalloc_state_main;
static bool obmalloc_state_initialized;
static inline int
has_own_state(PyInterpreterState *interp)
{
return (_Py_IsMainInterpreter(interp) ||
!(interp->feature_flags & Py_RTFLAGS_USE_MAIN_OBMALLOC) ||
_Py_IsMainInterpreterFinalizing(interp));
}
static inline OMState *
get_state(void)
{
PyInterpreterState *interp = _PyInterpreterState_GET();
assert(interp->obmalloc != NULL); // otherwise not initialized or freed
return interp->obmalloc;
}
// These macros all rely on a local "state" variable.
#define usedpools (state->pools.used)
#define allarenas (state->mgmt.arenas)
#define maxarenas (state->mgmt.maxarenas)
#define unused_arena_objects (state->mgmt.unused_arena_objects)
#define usable_arenas (state->mgmt.usable_arenas)
#define nfp2lasta (state->mgmt.nfp2lasta)
#define narenas_currently_allocated (state->mgmt.narenas_currently_allocated)
#define ntimes_arena_allocated (state->mgmt.ntimes_arena_allocated)
#define narenas_highwater (state->mgmt.narenas_highwater)
#define raw_allocated_blocks (state->mgmt.raw_allocated_blocks)
#ifdef WITH_MIMALLOC
static bool count_blocks(
const mi_heap_t* heap, const mi_heap_area_t* area,
void* block, size_t block_size, void* allocated_blocks)
{
*(size_t *)allocated_blocks += area->used;
return 1;
}
static Py_ssize_t
get_mimalloc_allocated_blocks(PyInterpreterState *interp)
{
size_t allocated_blocks = 0;
#ifdef Py_GIL_DISABLED
for (PyThreadState *t = interp->threads.head; t != NULL; t = t->next) {
_PyThreadStateImpl *tstate = (_PyThreadStateImpl *)t;
for (int i = 0; i < _Py_MIMALLOC_HEAP_COUNT; i++) {
mi_heap_t *heap = &tstate->mimalloc.heaps[i];
mi_heap_visit_blocks(heap, false, &count_blocks, &allocated_blocks);
}
}
mi_abandoned_pool_t *pool = &interp->mimalloc.abandoned_pool;
for (uint8_t tag = 0; tag < _Py_MIMALLOC_HEAP_COUNT; tag++) {
_mi_abandoned_pool_visit_blocks(pool, tag, false, &count_blocks,
&allocated_blocks);
}
#else
// TODO(sgross): this only counts the current thread's blocks.
mi_heap_t *heap = mi_heap_get_default();
mi_heap_visit_blocks(heap, false, &count_blocks, &allocated_blocks);
#endif
return allocated_blocks;
}
#endif
Py_ssize_t
_PyInterpreterState_GetAllocatedBlocks(PyInterpreterState *interp)
{
#ifdef WITH_MIMALLOC
if (_PyMem_MimallocEnabled()) {
return get_mimalloc_allocated_blocks(interp);
}
#endif
#ifdef Py_DEBUG
assert(has_own_state(interp));
#else
if (!has_own_state(interp)) {
_Py_FatalErrorFunc(__func__,
"the interpreter doesn't have its own allocator");
}
#endif
OMState *state = interp->obmalloc;
if (state == NULL) {
return 0;
}
Py_ssize_t n = raw_allocated_blocks;
/* add up allocated blocks for used pools */
for (uint i = 0; i < maxarenas; ++i) {
/* Skip arenas which are not allocated. */
if (allarenas[i].address == 0) {
continue;
}
uintptr_t base = (uintptr_t)_Py_ALIGN_UP(allarenas[i].address, POOL_SIZE);
/* visit every pool in the arena */
assert(base <= (uintptr_t) allarenas[i].pool_address);
for (; base < (uintptr_t) allarenas[i].pool_address; base += POOL_SIZE) {
poolp p = (poolp)base;
n += p->ref.count;
}
}
return n;
}
static void free_obmalloc_arenas(PyInterpreterState *interp);
void
_PyInterpreterState_FinalizeAllocatedBlocks(PyInterpreterState *interp)
{
#ifdef WITH_MIMALLOC
if (_PyMem_MimallocEnabled()) {
Py_ssize_t leaked = _PyInterpreterState_GetAllocatedBlocks(interp);
interp->runtime->obmalloc.interpreter_leaks += leaked;
return;
}
#endif
if (has_own_state(interp) && interp->obmalloc != NULL) {
Py_ssize_t leaked = _PyInterpreterState_GetAllocatedBlocks(interp);
assert(has_own_state(interp) || leaked == 0);
interp->runtime->obmalloc.interpreter_leaks += leaked;
if (_PyMem_obmalloc_state_on_heap(interp) && leaked == 0) {
// free the obmalloc arenas and radix tree nodes. If leaked > 0
// then some of the memory allocated by obmalloc has not been
// freed. It might be safe to free the arenas in that case but
// it's possible that extension modules are still using that
// memory. So, it is safer to not free and to leak. Perhaps there
// should be warning when this happens. It should be possible to
// use a tool like "-fsanitize=address" to track down these leaks.
free_obmalloc_arenas(interp);
}
}
}
static Py_ssize_t get_num_global_allocated_blocks(_PyRuntimeState *);
/* We preserve the number of blocks leaked during runtime finalization,
so they can be reported if the runtime is initialized again. */
// XXX We don't lose any information by dropping this,
// so we should consider doing so.
static Py_ssize_t last_final_leaks = 0;
void
_Py_FinalizeAllocatedBlocks(_PyRuntimeState *runtime)
{
last_final_leaks = get_num_global_allocated_blocks(runtime);
runtime->obmalloc.interpreter_leaks = 0;
}
static Py_ssize_t
get_num_global_allocated_blocks(_PyRuntimeState *runtime)
{
Py_ssize_t total = 0;
if (_PyRuntimeState_GetFinalizing(runtime) != NULL) {
PyInterpreterState *interp = _PyInterpreterState_Main();
if (interp == NULL) {
/* We are at the very end of runtime finalization.
We can't rely on finalizing->interp since that thread
state is probably already freed, so we don't worry
about it. */
assert(PyInterpreterState_Head() == NULL);
}
else {
assert(interp != NULL);
/* It is probably the last interpreter but not necessarily. */
assert(PyInterpreterState_Next(interp) == NULL);
total += _PyInterpreterState_GetAllocatedBlocks(interp);
}
}
else {
_PyEval_StopTheWorldAll(&_PyRuntime);
HEAD_LOCK(runtime);
PyInterpreterState *interp = PyInterpreterState_Head();
assert(interp != NULL);
#ifdef Py_DEBUG
int got_main = 0;
#endif
for (; interp != NULL; interp = PyInterpreterState_Next(interp)) {
#ifdef Py_DEBUG
if (_Py_IsMainInterpreter(interp)) {
assert(!got_main);
got_main = 1;
assert(has_own_state(interp));
}
#endif
if (has_own_state(interp)) {
total += _PyInterpreterState_GetAllocatedBlocks(interp);
}
}
HEAD_UNLOCK(runtime);
_PyEval_StartTheWorldAll(&_PyRuntime);
#ifdef Py_DEBUG
assert(got_main);
#endif
}
total += runtime->obmalloc.interpreter_leaks;
total += last_final_leaks;
return total;
}
Py_ssize_t
_Py_GetGlobalAllocatedBlocks(void)
{
return get_num_global_allocated_blocks(&_PyRuntime);
}
#if WITH_PYMALLOC_RADIX_TREE
/*==========================================================================*/
/* radix tree for tracking arena usage. */
#define arena_map_root (state->usage.arena_map_root)
#ifdef USE_INTERIOR_NODES
#define arena_map_mid_count (state->usage.arena_map_mid_count)
#define arena_map_bot_count (state->usage.arena_map_bot_count)
#endif
/* Return a pointer to a bottom tree node, return NULL if it doesn't exist or
* it cannot be created */
static inline Py_ALWAYS_INLINE arena_map_bot_t *
arena_map_get(OMState *state, pymem_block *p, int create)
{
#ifdef USE_INTERIOR_NODES
/* sanity check that IGNORE_BITS is correct */
assert(HIGH_BITS(p) == HIGH_BITS(&arena_map_root));
int i1 = MAP_TOP_INDEX(p);
if (arena_map_root.ptrs[i1] == NULL) {
if (!create) {
return NULL;
}
arena_map_mid_t *n = PyMem_RawCalloc(1, sizeof(arena_map_mid_t));
if (n == NULL) {
return NULL;
}
arena_map_root.ptrs[i1] = n;
arena_map_mid_count++;
}
int i2 = MAP_MID_INDEX(p);
if (arena_map_root.ptrs[i1]->ptrs[i2] == NULL) {
if (!create) {
return NULL;
}
arena_map_bot_t *n = PyMem_RawCalloc(1, sizeof(arena_map_bot_t));
if (n == NULL) {
return NULL;
}
arena_map_root.ptrs[i1]->ptrs[i2] = n;
arena_map_bot_count++;
}
return arena_map_root.ptrs[i1]->ptrs[i2];
#else
return &arena_map_root;
#endif
}
/* The radix tree only tracks arenas. So, for 16 MiB arenas, we throw
* away 24 bits of the address. That reduces the space requirement of
* the tree compared to similar radix tree page-map schemes. In
* exchange for slashing the space requirement, it needs more
* computation to check an address.
*
* Tracking coverage is done by "ideal" arena address. It is easier to
* explain in decimal so let's say that the arena size is 100 bytes.
* Then, ideal addresses are 100, 200, 300, etc. For checking if a
* pointer address is inside an actual arena, we have to check two ideal
* arena addresses. E.g. if pointer is 357, we need to check 200 and
* 300. In the rare case that an arena is aligned in the ideal way
* (e.g. base address of arena is 200) then we only have to check one
* ideal address.
*
* The tree nodes for 200 and 300 both store the address of arena.
* There are two cases: the arena starts at a lower ideal arena and
* extends to this one, or the arena starts in this arena and extends to
* the next ideal arena. The tail_lo and tail_hi members correspond to
* these two cases.
*/
/* mark or unmark addresses covered by arena */
static int
arena_map_mark_used(OMState *state, uintptr_t arena_base, int is_used)
{
/* sanity check that IGNORE_BITS is correct */
assert(HIGH_BITS(arena_base) == HIGH_BITS(&arena_map_root));
arena_map_bot_t *n_hi = arena_map_get(
state, (pymem_block *)arena_base, is_used);
if (n_hi == NULL) {
assert(is_used); /* otherwise node should already exist */
return 0; /* failed to allocate space for node */
}
int i3 = MAP_BOT_INDEX((pymem_block *)arena_base);
int32_t tail = (int32_t)(arena_base & ARENA_SIZE_MASK);
if (tail == 0) {
/* is ideal arena address */
n_hi->arenas[i3].tail_hi = is_used ? -1 : 0;
}
else {
/* arena_base address is not ideal (aligned to arena size) and
* so it potentially covers two MAP_BOT nodes. Get the MAP_BOT node
* for the next arena. Note that it might be in different MAP_TOP
* and MAP_MID nodes as well so we need to call arena_map_get()
* again (do the full tree traversal).
*/
n_hi->arenas[i3].tail_hi = is_used ? tail : 0;
uintptr_t arena_base_next = arena_base + ARENA_SIZE;
/* If arena_base is a legit arena address, so is arena_base_next - 1
* (last address in arena). If arena_base_next overflows then it
* must overflow to 0. However, that would mean arena_base was
* "ideal" and we should not be in this case. */
assert(arena_base < arena_base_next);
arena_map_bot_t *n_lo = arena_map_get(
state, (pymem_block *)arena_base_next, is_used);
if (n_lo == NULL) {
assert(is_used); /* otherwise should already exist */
n_hi->arenas[i3].tail_hi = 0;
return 0; /* failed to allocate space for node */
}
int i3_next = MAP_BOT_INDEX(arena_base_next);
n_lo->arenas[i3_next].tail_lo = is_used ? tail : 0;
}
return 1;
}
/* Return true if 'p' is a pointer inside an obmalloc arena.
* _PyObject_Free() calls this so it needs to be very fast. */
static int
arena_map_is_used(OMState *state, pymem_block *p)
{
arena_map_bot_t *n = arena_map_get(state, p, 0);
if (n == NULL) {
return 0;
}
int i3 = MAP_BOT_INDEX(p);
/* ARENA_BITS must be < 32 so that the tail is a non-negative int32_t. */
int32_t hi = n->arenas[i3].tail_hi;
int32_t lo = n->arenas[i3].tail_lo;
int32_t tail = (int32_t)(AS_UINT(p) & ARENA_SIZE_MASK);
return (tail < lo) || (tail >= hi && hi != 0);
}
/* end of radix tree logic */
/*==========================================================================*/
#endif /* WITH_PYMALLOC_RADIX_TREE */
/* Allocate a new arena. If we run out of memory, return NULL. Else
* allocate a new arena, and return the address of an arena_object
* describing the new arena. It's expected that the caller will set
* `usable_arenas` to the return value.
*/
static struct arena_object*
new_arena(OMState *state)
{
struct arena_object* arenaobj;
uint excess; /* number of bytes above pool alignment */
void *address;
int debug_stats = _PyRuntime.obmalloc.dump_debug_stats;
if (debug_stats == -1) {
const char *opt = Py_GETENV("PYTHONMALLOCSTATS");
debug_stats = (opt != NULL && *opt != '\0');
_PyRuntime.obmalloc.dump_debug_stats = debug_stats;
}
if (debug_stats) {
_PyObject_DebugMallocStats(stderr);
}
if (unused_arena_objects == NULL) {
uint i;
uint numarenas;
size_t nbytes;
/* Double the number of arena objects on each allocation.
* Note that it's possible for `numarenas` to overflow.
*/
numarenas = maxarenas ? maxarenas << 1 : INITIAL_ARENA_OBJECTS;
if (numarenas <= maxarenas)
return NULL; /* overflow */
#if SIZEOF_SIZE_T <= SIZEOF_INT
if (numarenas > SIZE_MAX / sizeof(*allarenas))
return NULL; /* overflow */
#endif
nbytes = numarenas * sizeof(*allarenas);
arenaobj = (struct arena_object *)PyMem_RawRealloc(allarenas, nbytes);
if (arenaobj == NULL)
return NULL;
allarenas = arenaobj;
/* We might need to fix pointers that were copied. However,
* new_arena only gets called when all the pages in the
* previous arenas are full. Thus, there are *no* pointers
* into the old array. Thus, we don't have to worry about
* invalid pointers. Just to be sure, some asserts:
*/
assert(usable_arenas == NULL);
assert(unused_arena_objects == NULL);
/* Put the new arenas on the unused_arena_objects list. */
for (i = maxarenas; i < numarenas; ++i) {
allarenas[i].address = 0; /* mark as unassociated */
allarenas[i].nextarena = i < numarenas - 1 ?
&allarenas[i+1] : NULL;
}
/* Update globals. */
unused_arena_objects = &allarenas[maxarenas];
maxarenas = numarenas;
}
/* Take the next available arena object off the head of the list. */
assert(unused_arena_objects != NULL);
arenaobj = unused_arena_objects;
unused_arena_objects = arenaobj->nextarena;
assert(arenaobj->address == 0);
address = _PyObject_Arena.alloc(_PyObject_Arena.ctx, ARENA_SIZE);
#if WITH_PYMALLOC_RADIX_TREE
if (address != NULL) {
if (!arena_map_mark_used(state, (uintptr_t)address, 1)) {
/* marking arena in radix tree failed, abort */
_PyObject_Arena.free(_PyObject_Arena.ctx, address, ARENA_SIZE);
address = NULL;
}
}
#endif
if (address == NULL) {
/* The allocation failed: return NULL after putting the
* arenaobj back.
*/
arenaobj->nextarena = unused_arena_objects;
unused_arena_objects = arenaobj;
return NULL;
}
arenaobj->address = (uintptr_t)address;
++narenas_currently_allocated;
++ntimes_arena_allocated;
if (narenas_currently_allocated > narenas_highwater)
narenas_highwater = narenas_currently_allocated;
arenaobj->freepools = NULL;
/* pool_address <- first pool-aligned address in the arena
nfreepools <- number of whole pools that fit after alignment */
arenaobj->pool_address = (pymem_block*)arenaobj->address;
arenaobj->nfreepools = MAX_POOLS_IN_ARENA;
excess = (uint)(arenaobj->address & POOL_SIZE_MASK);
if (excess != 0) {
--arenaobj->nfreepools;
arenaobj->pool_address += POOL_SIZE - excess;
}
arenaobj->ntotalpools = arenaobj->nfreepools;
return arenaobj;
}
#if WITH_PYMALLOC_RADIX_TREE
/* Return true if and only if P is an address that was allocated by
pymalloc. When the radix tree is used, 'poolp' is unused.
*/
static bool
address_in_range(OMState *state, void *p, poolp Py_UNUSED(pool))
{
return arena_map_is_used(state, p);
}
#else
/*
address_in_range(P, POOL)
Return true if and only if P is an address that was allocated by pymalloc.
POOL must be the pool address associated with P, i.e., POOL = POOL_ADDR(P)
(the caller is asked to compute this because the macro expands POOL more than
once, and for efficiency it's best for the caller to assign POOL_ADDR(P) to a
variable and pass the latter to the macro; because address_in_range is
called on every alloc/realloc/free, micro-efficiency is important here).
Tricky: Let B be the arena base address associated with the pool, B =
arenas[(POOL)->arenaindex].address. Then P belongs to the arena if and only if
B <= P < B + ARENA_SIZE
Subtracting B throughout, this is true iff
0 <= P-B < ARENA_SIZE
By using unsigned arithmetic, the "0 <=" half of the test can be skipped.
Obscure: A PyMem "free memory" function can call the pymalloc free or realloc
before the first arena has been allocated. `arenas` is still NULL in that
case. We're relying on that maxarenas is also 0 in that case, so that
(POOL)->arenaindex < maxarenas must be false, saving us from trying to index
into a NULL arenas.
Details: given P and POOL, the arena_object corresponding to P is AO =
arenas[(POOL)->arenaindex]. Suppose obmalloc controls P. Then (barring wild
stores, etc), POOL is the correct address of P's pool, AO.address is the
correct base address of the pool's arena, and P must be within ARENA_SIZE of
AO.address. In addition, AO.address is not 0 (no arena can start at address 0
(NULL)). Therefore address_in_range correctly reports that obmalloc
controls P.
Now suppose obmalloc does not control P (e.g., P was obtained via a direct
call to the system malloc() or realloc()). (POOL)->arenaindex may be anything
in this case -- it may even be uninitialized trash. If the trash arenaindex
is >= maxarenas, the macro correctly concludes at once that obmalloc doesn't
control P.
Else arenaindex is < maxarena, and AO is read up. If AO corresponds to an
allocated arena, obmalloc controls all the memory in slice AO.address :
AO.address+ARENA_SIZE. By case assumption, P is not controlled by obmalloc,
so P doesn't lie in that slice, so the macro correctly reports that P is not
controlled by obmalloc.
Finally, if P is not controlled by obmalloc and AO corresponds to an unused
arena_object (one not currently associated with an allocated arena),
AO.address is 0, and the second test in the macro reduces to:
P < ARENA_SIZE
If P >= ARENA_SIZE (extremely likely), the macro again correctly concludes
that P is not controlled by obmalloc. However, if P < ARENA_SIZE, this part
of the test still passes, and the third clause (AO.address != 0) is necessary
to get the correct result: AO.address is 0 in this case, so the macro
correctly reports that P is not controlled by obmalloc (despite that P lies in
slice AO.address : AO.address + ARENA_SIZE).
Note: The third (AO.address != 0) clause was added in Python 2.5. Before
2.5, arenas were never free()'ed, and an arenaindex < maxarena always
corresponded to a currently-allocated arena, so the "P is not controlled by
obmalloc, AO corresponds to an unused arena_object, and P < ARENA_SIZE" case
was impossible.
Note that the logic is excruciating, and reading up possibly uninitialized
memory when P is not controlled by obmalloc (to get at (POOL)->arenaindex)
creates problems for some memory debuggers. The overwhelming advantage is
that this test determines whether an arbitrary address is controlled by
obmalloc in a small constant time, independent of the number of arenas
obmalloc controls. Since this test is needed at every entry point, it's
extremely desirable that it be this fast.
*/
static bool _Py_NO_SANITIZE_ADDRESS
_Py_NO_SANITIZE_THREAD
_Py_NO_SANITIZE_MEMORY
address_in_range(OMState *state, void *p, poolp pool)
{
// Since address_in_range may be reading from memory which was not allocated
// by Python, it is important that pool->arenaindex is read only once, as
// another thread may be concurrently modifying the value without holding
// the GIL. The following dance forces the compiler to read pool->arenaindex
// only once.
uint arenaindex = *((volatile uint *)&pool->arenaindex);
return arenaindex < maxarenas &&
(uintptr_t)p - allarenas[arenaindex].address < ARENA_SIZE &&
allarenas[arenaindex].address != 0;
}
#endif /* !WITH_PYMALLOC_RADIX_TREE */
/*==========================================================================*/
// Called when freelist is exhausted. Extend the freelist if there is
// space for a block. Otherwise, remove this pool from usedpools.
static void
pymalloc_pool_extend(poolp pool, uint size)
{
if (UNLIKELY(pool->nextoffset <= pool->maxnextoffset)) {
/* There is room for another block. */
pool->freeblock = (pymem_block*)pool + pool->nextoffset;
pool->nextoffset += INDEX2SIZE(size);
*(pymem_block **)(pool->freeblock) = NULL;
return;
}
/* Pool is full, unlink from used pools. */
poolp next;
next = pool->nextpool;
pool = pool->prevpool;
next->prevpool = pool;
pool->nextpool = next;
}
/* called when pymalloc_alloc can not allocate a block from usedpool.
* This function takes new pool and allocate a block from it.
*/
static void*
allocate_from_new_pool(OMState *state, uint size)
{
/* There isn't a pool of the right size class immediately
* available: use a free pool.
*/
if (UNLIKELY(usable_arenas == NULL)) {
/* No arena has a free pool: allocate a new arena. */
#ifdef WITH_MEMORY_LIMITS
if (narenas_currently_allocated >= MAX_ARENAS) {
return NULL;
}
#endif
usable_arenas = new_arena(state);
if (usable_arenas == NULL) {
return NULL;
}
usable_arenas->nextarena = usable_arenas->prevarena = NULL;
assert(nfp2lasta[usable_arenas->nfreepools] == NULL);
nfp2lasta[usable_arenas->nfreepools] = usable_arenas;
}
assert(usable_arenas->address != 0);
/* This arena already had the smallest nfreepools value, so decreasing
* nfreepools doesn't change that, and we don't need to rearrange the
* usable_arenas list. However, if the arena becomes wholly allocated,
* we need to remove its arena_object from usable_arenas.
*/
assert(usable_arenas->nfreepools > 0);
if (nfp2lasta[usable_arenas->nfreepools] == usable_arenas) {
/* It's the last of this size, so there won't be any. */
nfp2lasta[usable_arenas->nfreepools] = NULL;
}
/* If any free pools will remain, it will be the new smallest. */
if (usable_arenas->nfreepools > 1) {
assert(nfp2lasta[usable_arenas->nfreepools - 1] == NULL);
nfp2lasta[usable_arenas->nfreepools - 1] = usable_arenas;
}
/* Try to get a cached free pool. */
poolp pool = usable_arenas->freepools;
if (LIKELY(pool != NULL)) {
/* Unlink from cached pools. */
usable_arenas->freepools = pool->nextpool;
usable_arenas->nfreepools--;
if (UNLIKELY(usable_arenas->nfreepools == 0)) {
/* Wholly allocated: remove. */
assert(usable_arenas->freepools == NULL);
assert(usable_arenas->nextarena == NULL ||
usable_arenas->nextarena->prevarena ==
usable_arenas);
usable_arenas = usable_arenas->nextarena;
if (usable_arenas != NULL) {
usable_arenas->prevarena = NULL;
assert(usable_arenas->address != 0);
}
}
else {
/* nfreepools > 0: it must be that freepools
* isn't NULL, or that we haven't yet carved
* off all the arena's pools for the first
* time.
*/
assert(usable_arenas->freepools != NULL ||
usable_arenas->pool_address <=
(pymem_block*)usable_arenas->address +
ARENA_SIZE - POOL_SIZE);
}
}
else {
/* Carve off a new pool. */
assert(usable_arenas->nfreepools > 0);
assert(usable_arenas->freepools == NULL);
pool = (poolp)usable_arenas->pool_address;
assert((pymem_block*)pool <= (pymem_block*)usable_arenas->address +
ARENA_SIZE - POOL_SIZE);
pool->arenaindex = (uint)(usable_arenas - allarenas);
assert(&allarenas[pool->arenaindex] == usable_arenas);
pool->szidx = DUMMY_SIZE_IDX;
usable_arenas->pool_address += POOL_SIZE;
--usable_arenas->nfreepools;
if (usable_arenas->nfreepools == 0) {
assert(usable_arenas->nextarena == NULL ||
usable_arenas->nextarena->prevarena ==
usable_arenas);
/* Unlink the arena: it is completely allocated. */
usable_arenas = usable_arenas->nextarena;
if (usable_arenas != NULL) {
usable_arenas->prevarena = NULL;
assert(usable_arenas->address != 0);
}
}
}
/* Frontlink to used pools. */
pymem_block *bp;
poolp next = usedpools[size + size]; /* == prev */
pool->nextpool = next;
pool->prevpool = next;
next->nextpool = pool;
next->prevpool = pool;
pool->ref.count = 1;
if (pool->szidx == size) {
/* Luckily, this pool last contained blocks
* of the same size class, so its header
* and free list are already initialized.
*/
bp = pool->freeblock;
assert(bp != NULL);
pool->freeblock = *(pymem_block **)bp;
return bp;
}
/*
* Initialize the pool header, set up the free list to
* contain just the second block, and return the first
* block.
*/
pool->szidx = size;
size = INDEX2SIZE(size);
bp = (pymem_block *)pool + POOL_OVERHEAD;
pool->nextoffset = POOL_OVERHEAD + (size << 1);
pool->maxnextoffset = POOL_SIZE - size;
pool->freeblock = bp + size;
*(pymem_block **)(pool->freeblock) = NULL;
return bp;
}
/* pymalloc allocator
Return a pointer to newly allocated memory if pymalloc allocated memory.
Return NULL if pymalloc failed to allocate the memory block: on bigger
requests, on error in the code below (as a last chance to serve the request)
or when the max memory limit has been reached.
*/
static inline void*
pymalloc_alloc(OMState *state, void *Py_UNUSED(ctx), size_t nbytes)
{
#ifdef WITH_VALGRIND
if (UNLIKELY(running_on_valgrind == -1)) {
running_on_valgrind = RUNNING_ON_VALGRIND;
}
if (UNLIKELY(running_on_valgrind)) {
return NULL;
}
#endif
if (UNLIKELY(nbytes == 0)) {
return NULL;
}
if (UNLIKELY(nbytes > SMALL_REQUEST_THRESHOLD)) {
return NULL;
}
uint size = (uint)(nbytes - 1) >> ALIGNMENT_SHIFT;
poolp pool = usedpools[size + size];
pymem_block *bp;
if (LIKELY(pool != pool->nextpool)) {
/*
* There is a used pool for this size class.
* Pick up the head block of its free list.
*/
++pool->ref.count;
bp = pool->freeblock;
assert(bp != NULL);
if (UNLIKELY((pool->freeblock = *(pymem_block **)bp) == NULL)) {
// Reached the end of the free list, try to extend it.
pymalloc_pool_extend(pool, size);
}
}
else {
/* There isn't a pool of the right size class immediately
* available: use a free pool.
*/
bp = allocate_from_new_pool(state, size);
}
return (void *)bp;
}
void *
_PyObject_Malloc(void *ctx, size_t nbytes)
{
OMState *state = get_state();
void* ptr = pymalloc_alloc(state, ctx, nbytes);
if (LIKELY(ptr != NULL)) {
return ptr;
}
ptr = PyMem_RawMalloc(nbytes);
if (ptr != NULL) {
raw_allocated_blocks++;
}
return ptr;
}
void *
_PyObject_Calloc(void *ctx, size_t nelem, size_t elsize)
{
assert(elsize == 0 || nelem <= (size_t)PY_SSIZE_T_MAX / elsize);
size_t nbytes = nelem * elsize;
OMState *state = get_state();
void* ptr = pymalloc_alloc(state, ctx, nbytes);
if (LIKELY(ptr != NULL)) {
memset(ptr, 0, nbytes);
return ptr;
}
ptr = PyMem_RawCalloc(nelem, elsize);
if (ptr != NULL) {
raw_allocated_blocks++;
}
return ptr;
}
static void
insert_to_usedpool(OMState *state, poolp pool)
{
assert(pool->ref.count > 0); /* else the pool is empty */
uint size = pool->szidx;
poolp next = usedpools[size + size];
poolp prev = next->prevpool;
/* insert pool before next: prev <-> pool <-> next */
pool->nextpool = next;
pool->prevpool = prev;
next->prevpool = pool;
prev->nextpool = pool;
}
static void
insert_to_freepool(OMState *state, poolp pool)
{
poolp next = pool->nextpool;
poolp prev = pool->prevpool;
next->prevpool = prev;
prev->nextpool = next;
/* Link the pool to freepools. This is a singly-linked
* list, and pool->prevpool isn't used there.
*/
struct arena_object *ao = &allarenas[pool->arenaindex];
pool->nextpool = ao->freepools;
ao->freepools = pool;
uint nf = ao->nfreepools;
/* If this is the rightmost arena with this number of free pools,
* nfp2lasta[nf] needs to change. Caution: if nf is 0, there
* are no arenas in usable_arenas with that value.
*/
struct arena_object* lastnf = nfp2lasta[nf];
assert((nf == 0 && lastnf == NULL) ||
(nf > 0 &&
lastnf != NULL &&
lastnf->nfreepools == nf &&
(lastnf->nextarena == NULL ||
nf < lastnf->nextarena->nfreepools)));
if (lastnf == ao) { /* it is the rightmost */
struct arena_object* p = ao->prevarena;
nfp2lasta[nf] = (p != NULL && p->nfreepools == nf) ? p : NULL;
}
ao->nfreepools = ++nf;
/* All the rest is arena management. We just freed
* a pool, and there are 4 cases for arena mgmt:
* 1. If all the pools are free, return the arena to
* the system free(). Except if this is the last
* arena in the list, keep it to avoid thrashing:
* keeping one wholly free arena in the list avoids
* pathological cases where a simple loop would
* otherwise provoke needing to allocate and free an
* arena on every iteration. See bpo-37257.
* 2. If this is the only free pool in the arena,
* add the arena back to the `usable_arenas` list.
* 3. If the "next" arena has a smaller count of free
* pools, we have to "slide this arena right" to
* restore that usable_arenas is sorted in order of
* nfreepools.
* 4. Else there's nothing more to do.
*/
if (nf == ao->ntotalpools && ao->nextarena != NULL) {
/* Case 1. First unlink ao from usable_arenas.
*/
assert(ao->prevarena == NULL ||
ao->prevarena->address != 0);
assert(ao ->nextarena == NULL ||
ao->nextarena->address != 0);
/* Fix the pointer in the prevarena, or the
* usable_arenas pointer.
*/
if (ao->prevarena == NULL) {
usable_arenas = ao->nextarena;
assert(usable_arenas == NULL ||
usable_arenas->address != 0);
}
else {
assert(ao->prevarena->nextarena == ao);
ao->prevarena->nextarena =
ao->nextarena;
}
/* Fix the pointer in the nextarena. */
if (ao->nextarena != NULL) {
assert(ao->nextarena->prevarena == ao);
ao->nextarena->prevarena =
ao->prevarena;
}
/* Record that this arena_object slot is
* available to be reused.
*/
ao->nextarena = unused_arena_objects;
unused_arena_objects = ao;
#if WITH_PYMALLOC_RADIX_TREE
/* mark arena region as not under control of obmalloc */
arena_map_mark_used(state, ao->address, 0);
#endif
/* Free the entire arena. */
_PyObject_Arena.free(_PyObject_Arena.ctx,
(void *)ao->address, ARENA_SIZE);
ao->address = 0; /* mark unassociated */
--narenas_currently_allocated;
return;
}
if (nf == 1) {
/* Case 2. Put ao at the head of
* usable_arenas. Note that because
* ao->nfreepools was 0 before, ao isn't
* currently on the usable_arenas list.
*/
ao->nextarena = usable_arenas;
ao->prevarena = NULL;
if (usable_arenas)
usable_arenas->prevarena = ao;
usable_arenas = ao;
assert(usable_arenas->address != 0);
if (nfp2lasta[1] == NULL) {
nfp2lasta[1] = ao;
}
return;
}
/* If this arena is now out of order, we need to keep
* the list sorted. The list is kept sorted so that
* the "most full" arenas are used first, which allows
* the nearly empty arenas to be completely freed. In
* a few un-scientific tests, it seems like this
* approach allowed a lot more memory to be freed.
*/
/* If this is the only arena with nf, record that. */
if (nfp2lasta[nf] == NULL) {
nfp2lasta[nf] = ao;
} /* else the rightmost with nf doesn't change */
/* If this was the rightmost of the old size, it remains in place. */
if (ao == lastnf) {
/* Case 4. Nothing to do. */
return;
}
/* If ao were the only arena in the list, the last block would have
* gotten us out.
*/
assert(ao->nextarena != NULL);
/* Case 3: We have to move the arena towards the end of the list,
* because it has more free pools than the arena to its right. It needs
* to move to follow lastnf.
* First unlink ao from usable_arenas.
*/
if (ao->prevarena != NULL) {
/* ao isn't at the head of the list */
assert(ao->prevarena->nextarena == ao);
ao->prevarena->nextarena = ao->nextarena;
}
else {
/* ao is at the head of the list */
assert(usable_arenas == ao);
usable_arenas = ao->nextarena;
}
ao->nextarena->prevarena = ao->prevarena;
/* And insert after lastnf. */
ao->prevarena = lastnf;
ao->nextarena = lastnf->nextarena;
if (ao->nextarena != NULL) {
ao->nextarena->prevarena = ao;
}
lastnf->nextarena = ao;
/* Verify that the swaps worked. */
assert(ao->nextarena == NULL || nf <= ao->nextarena->nfreepools);
assert(ao->prevarena == NULL || nf > ao->prevarena->nfreepools);
assert(ao->nextarena == NULL || ao->nextarena->prevarena == ao);
assert((usable_arenas == ao && ao->prevarena == NULL)
|| ao->prevarena->nextarena == ao);
}
/* Free a memory block allocated by pymalloc_alloc().
Return 1 if it was freed.
Return 0 if the block was not allocated by pymalloc_alloc(). */
static inline int
pymalloc_free(OMState *state, void *Py_UNUSED(ctx), void *p)
{
assert(p != NULL);
#ifdef WITH_VALGRIND
if (UNLIKELY(running_on_valgrind > 0)) {
return 0;
}
#endif
poolp pool = POOL_ADDR(p);
if (UNLIKELY(!address_in_range(state, p, pool))) {
return 0;
}
/* We allocated this address. */
/* Link p to the start of the pool's freeblock list. Since
* the pool had at least the p block outstanding, the pool
* wasn't empty (so it's already in a usedpools[] list, or
* was full and is in no list -- it's not in the freeblocks
* list in any case).
*/
assert(pool->ref.count > 0); /* else it was empty */
pymem_block *lastfree = pool->freeblock;
*(pymem_block **)p = lastfree;
pool->freeblock = (pymem_block *)p;
pool->ref.count--;
if (UNLIKELY(lastfree == NULL)) {
/* Pool was full, so doesn't currently live in any list:
* link it to the front of the appropriate usedpools[] list.
* This mimics LRU pool usage for new allocations and
* targets optimal filling when several pools contain
* blocks of the same size class.
*/
insert_to_usedpool(state, pool);
return 1;
}
/* freeblock wasn't NULL, so the pool wasn't full,
* and the pool is in a usedpools[] list.
*/
if (LIKELY(pool->ref.count != 0)) {
/* pool isn't empty: leave it in usedpools */
return 1;
}
/* Pool is now empty: unlink from usedpools, and
* link to the front of freepools. This ensures that
* previously freed pools will be allocated later
* (being not referenced, they are perhaps paged out).
*/
insert_to_freepool(state, pool);
return 1;
}
void
_PyObject_Free(void *ctx, void *p)
{
/* PyObject_Free(NULL) has no effect */
if (p == NULL) {
return;
}
OMState *state = get_state();
if (UNLIKELY(!pymalloc_free(state, ctx, p))) {
/* pymalloc didn't allocate this address */
PyMem_RawFree(p);
raw_allocated_blocks--;
}
}
/* pymalloc realloc.
If nbytes==0, then as the Python docs promise, we do not treat this like
free(p), and return a non-NULL result.
Return 1 if pymalloc reallocated memory and wrote the new pointer into
newptr_p.
Return 0 if pymalloc didn't allocated p. */
static int
pymalloc_realloc(OMState *state, void *ctx,
void **newptr_p, void *p, size_t nbytes)
{
void *bp;
poolp pool;
size_t size;
assert(p != NULL);
#ifdef WITH_VALGRIND
/* Treat running_on_valgrind == -1 the same as 0 */
if (UNLIKELY(running_on_valgrind > 0)) {
return 0;
}
#endif
pool = POOL_ADDR(p);
if (!address_in_range(state, p, pool)) {
/* pymalloc is not managing this block.
If nbytes <= SMALL_REQUEST_THRESHOLD, it's tempting to try to take
over this block. However, if we do, we need to copy the valid data
from the C-managed block to one of our blocks, and there's no
portable way to know how much of the memory space starting at p is
valid.
As bug 1185883 pointed out the hard way, it's possible that the
C-managed block is "at the end" of allocated VM space, so that a
memory fault can occur if we try to copy nbytes bytes starting at p.
Instead we punt: let C continue to manage this block. */
return 0;
}
/* pymalloc is in charge of this block */
size = INDEX2SIZE(pool->szidx);
if (nbytes <= size) {
/* The block is staying the same or shrinking.
If it's shrinking, there's a tradeoff: it costs cycles to copy the
block to a smaller size class, but it wastes memory not to copy it.
The compromise here is to copy on shrink only if at least 25% of
size can be shaved off. */
if (4 * nbytes > 3 * size) {
/* It's the same, or shrinking and new/old > 3/4. */
*newptr_p = p;
return 1;
}
size = nbytes;
}
bp = _PyObject_Malloc(ctx, nbytes);
if (bp != NULL) {
memcpy(bp, p, size);
_PyObject_Free(ctx, p);
}
*newptr_p = bp;
return 1;
}
void *
_PyObject_Realloc(void *ctx, void *ptr, size_t nbytes)
{
void *ptr2;
if (ptr == NULL) {
return _PyObject_Malloc(ctx, nbytes);
}
OMState *state = get_state();
if (pymalloc_realloc(state, ctx, &ptr2, ptr, nbytes)) {
return ptr2;
}
return PyMem_RawRealloc(ptr, nbytes);
}
#else /* ! WITH_PYMALLOC */
/*==========================================================================*/
/* pymalloc not enabled: Redirect the entry points to malloc. These will
* only be used by extensions that are compiled with pymalloc enabled. */
Py_ssize_t
_PyInterpreterState_GetAllocatedBlocks(PyInterpreterState *Py_UNUSED(interp))
{
return 0;
}
Py_ssize_t
_Py_GetGlobalAllocatedBlocks(void)
{
return 0;
}
void
_PyInterpreterState_FinalizeAllocatedBlocks(PyInterpreterState *Py_UNUSED(interp))
{
return;
}
void
_Py_FinalizeAllocatedBlocks(_PyRuntimeState *Py_UNUSED(runtime))
{
return;
}
#endif /* WITH_PYMALLOC */
/*==========================================================================*/
/* A x-platform debugging allocator. This doesn't manage memory directly,
* it wraps a real allocator, adding extra debugging info to the memory blocks.
*/
/* Uncomment this define to add the "serialno" field */
/* #define PYMEM_DEBUG_SERIALNO */
#ifdef PYMEM_DEBUG_SERIALNO
static size_t serialno = 0; /* incremented on each debug {m,re}alloc */
/* serialno is always incremented via calling this routine. The point is
* to supply a single place to set a breakpoint.
*/
static void
bumpserialno(void)
{
++serialno;
}
#endif
#define SST SIZEOF_SIZE_T
#ifdef PYMEM_DEBUG_SERIALNO
# define PYMEM_DEBUG_EXTRA_BYTES 4 * SST
#else
# define PYMEM_DEBUG_EXTRA_BYTES 3 * SST
#endif
/* Read sizeof(size_t) bytes at p as a big-endian size_t. */
static size_t
read_size_t(const void *p)
{
const uint8_t *q = (const uint8_t *)p;
size_t result = *q++;
int i;
for (i = SST; --i > 0; ++q)
result = (result << 8) | *q;
return result;
}
/* Write n as a big-endian size_t, MSB at address p, LSB at
* p + sizeof(size_t) - 1.
*/
static void
write_size_t(void *p, size_t n)
{
uint8_t *q = (uint8_t *)p + SST - 1;
int i;
for (i = SST; --i >= 0; --q) {
*q = (uint8_t)(n & 0xff);
n >>= 8;
}
}
static void
fill_mem_debug(debug_alloc_api_t *api, void *data, int c, size_t nbytes,
bool is_alloc)
{
#ifdef Py_GIL_DISABLED
if (api->api_id == 'o') {
// Don't overwrite the first few bytes of a PyObject allocation in the
// free-threaded build
_PyThreadStateImpl *tstate = (_PyThreadStateImpl *)_PyThreadState_GET();
size_t debug_offset;
if (is_alloc) {
debug_offset = tstate->mimalloc.current_object_heap->debug_offset;
}
else {
char *alloc = (char *)data - 2*SST; // start of the allocation
debug_offset = _mi_ptr_page(alloc)->debug_offset;
}
debug_offset -= 2*SST; // account for pymalloc extra bytes
if (debug_offset < nbytes) {
memset((char *)data + debug_offset, c, nbytes - debug_offset);
}
return;
}
#endif
memset(data, c, nbytes);
}
/* Let S = sizeof(size_t). The debug malloc asks for 4 * S extra bytes and
fills them with useful stuff, here calling the underlying malloc's result p:
p[0: S]
Number of bytes originally asked for. This is a size_t, big-endian (easier
to read in a memory dump).
p[S]
API ID. See PEP 445. This is a character, but seems undocumented.
p[S+1: 2*S]
Copies of PYMEM_FORBIDDENBYTE. Used to catch under- writes and reads.
p[2*S: 2*S+n]
The requested memory, filled with copies of PYMEM_CLEANBYTE.
Used to catch reference to uninitialized memory.
&p[2*S] is returned. Note that this is 8-byte aligned if pymalloc
handled the request itself.
p[2*S+n: 2*S+n+S]
Copies of PYMEM_FORBIDDENBYTE. Used to catch over- writes and reads.
p[2*S+n+S: 2*S+n+2*S]
A serial number, incremented by 1 on each call to _PyMem_DebugMalloc
and _PyMem_DebugRealloc.
This is a big-endian size_t.
If "bad memory" is detected later, the serial number gives an
excellent way to set a breakpoint on the next run, to capture the
instant at which this block was passed out.
If PYMEM_DEBUG_SERIALNO is not defined (default), the debug malloc only asks
for 3 * S extra bytes, and omits the last serialno field.
*/
static void *
_PyMem_DebugRawAlloc(int use_calloc, void *ctx, size_t nbytes)
{
debug_alloc_api_t *api = (debug_alloc_api_t *)ctx;
uint8_t *p; /* base address of malloc'ed pad block */
uint8_t *data; /* p + 2*SST == pointer to data bytes */
uint8_t *tail; /* data + nbytes == pointer to tail pad bytes */
size_t total; /* nbytes + PYMEM_DEBUG_EXTRA_BYTES */
if (nbytes > (size_t)PY_SSIZE_T_MAX - PYMEM_DEBUG_EXTRA_BYTES) {
/* integer overflow: can't represent total as a Py_ssize_t */
return NULL;
}
total = nbytes + PYMEM_DEBUG_EXTRA_BYTES;
/* Layout: [SSSS IFFF CCCC...CCCC FFFF NNNN]
^--- p ^--- data ^--- tail
S: nbytes stored as size_t
I: API identifier (1 byte)
F: Forbidden bytes (size_t - 1 bytes before, size_t bytes after)
C: Clean bytes used later to store actual data
N: Serial number stored as size_t
If PYMEM_DEBUG_SERIALNO is not defined (default), the last NNNN field
is omitted. */
if (use_calloc) {
p = (uint8_t *)api->alloc.calloc(api->alloc.ctx, 1, total);
}
else {
p = (uint8_t *)api->alloc.malloc(api->alloc.ctx, total);
}
if (p == NULL) {
return NULL;
}
data = p + 2*SST;
#ifdef PYMEM_DEBUG_SERIALNO
bumpserialno();
#endif
/* at p, write size (SST bytes), id (1 byte), pad (SST-1 bytes) */
write_size_t(p, nbytes);
p[SST] = (uint8_t)api->api_id;
memset(p + SST + 1, PYMEM_FORBIDDENBYTE, SST-1);
if (nbytes > 0 && !use_calloc) {
fill_mem_debug(api, data, PYMEM_CLEANBYTE, nbytes, true);
}
/* at tail, write pad (SST bytes) and serialno (SST bytes) */
tail = data + nbytes;
memset(tail, PYMEM_FORBIDDENBYTE, SST);
#ifdef PYMEM_DEBUG_SERIALNO
write_size_t(tail + SST, serialno);
#endif
return data;
}
void *
_PyMem_DebugRawMalloc(void *ctx, size_t nbytes)
{
return _PyMem_DebugRawAlloc(0, ctx, nbytes);
}
void *
_PyMem_DebugRawCalloc(void *ctx, size_t nelem, size_t elsize)
{
size_t nbytes;
assert(elsize == 0 || nelem <= (size_t)PY_SSIZE_T_MAX / elsize);
nbytes = nelem * elsize;
return _PyMem_DebugRawAlloc(1, ctx, nbytes);
}
/* The debug free first checks the 2*SST bytes on each end for sanity (in
particular, that the FORBIDDENBYTEs with the api ID are still intact).
Then fills the original bytes with PYMEM_DEADBYTE.
Then calls the underlying free.
*/
void
_PyMem_DebugRawFree(void *ctx, void *p)
{
/* PyMem_Free(NULL) has no effect */
if (p == NULL) {
return;
}
debug_alloc_api_t *api = (debug_alloc_api_t *)ctx;
uint8_t *q = (uint8_t *)p - 2*SST; /* address returned from malloc */
size_t nbytes;
_PyMem_DebugCheckAddress(__func__, api->api_id, p);
nbytes = read_size_t(q);
nbytes += PYMEM_DEBUG_EXTRA_BYTES - 2*SST;
memset(q, PYMEM_DEADBYTE, 2*SST);
fill_mem_debug(api, p, PYMEM_DEADBYTE, nbytes, false);
api->alloc.free(api->alloc.ctx, q);
}
void *
_PyMem_DebugRawRealloc(void *ctx, void *p, size_t nbytes)
{
if (p == NULL) {
return _PyMem_DebugRawAlloc(0, ctx, nbytes);
}
debug_alloc_api_t *api = (debug_alloc_api_t *)ctx;
uint8_t *head; /* base address of malloc'ed pad block */
uint8_t *data; /* pointer to data bytes */
uint8_t *r;
uint8_t *tail; /* data + nbytes == pointer to tail pad bytes */
size_t total; /* 2 * SST + nbytes + 2 * SST */
size_t original_nbytes;
#define ERASED_SIZE 64
_PyMem_DebugCheckAddress(__func__, api->api_id, p);
data = (uint8_t *)p;
head = data - 2*SST;
original_nbytes = read_size_t(head);
if (nbytes > (size_t)PY_SSIZE_T_MAX - PYMEM_DEBUG_EXTRA_BYTES) {
/* integer overflow: can't represent total as a Py_ssize_t */
return NULL;
}
total = nbytes + PYMEM_DEBUG_EXTRA_BYTES;
tail = data + original_nbytes;
#ifdef PYMEM_DEBUG_SERIALNO
size_t block_serialno = read_size_t(tail + SST);
#endif
#ifndef Py_GIL_DISABLED
/* Mark the header, the trailer, ERASED_SIZE bytes at the begin and
ERASED_SIZE bytes at the end as dead and save the copy of erased bytes.
*/
uint8_t save[2*ERASED_SIZE]; /* A copy of erased bytes. */
if (original_nbytes <= sizeof(save)) {
memcpy(save, data, original_nbytes);
memset(data - 2 * SST, PYMEM_DEADBYTE,
original_nbytes + PYMEM_DEBUG_EXTRA_BYTES);
}
else {
memcpy(save, data, ERASED_SIZE);
memset(head, PYMEM_DEADBYTE, ERASED_SIZE + 2 * SST);
memcpy(&save[ERASED_SIZE], tail - ERASED_SIZE, ERASED_SIZE);
memset(tail - ERASED_SIZE, PYMEM_DEADBYTE,
ERASED_SIZE + PYMEM_DEBUG_EXTRA_BYTES - 2 * SST);
}
#endif
/* Resize and add decorations. */
r = (uint8_t *)api->alloc.realloc(api->alloc.ctx, head, total);
if (r == NULL) {
/* if realloc() failed: rewrite header and footer which have
just been erased */
nbytes = original_nbytes;
}
else {
head = r;
#ifdef PYMEM_DEBUG_SERIALNO
bumpserialno();
block_serialno = serialno;
#endif
}
data = head + 2*SST;
write_size_t(head, nbytes);
head[SST] = (uint8_t)api->api_id;
memset(head + SST + 1, PYMEM_FORBIDDENBYTE, SST-1);
tail = data + nbytes;
memset(tail, PYMEM_FORBIDDENBYTE, SST);
#ifdef PYMEM_DEBUG_SERIALNO
write_size_t(tail + SST, block_serialno);
#endif
#ifndef Py_GIL_DISABLED
/* Restore saved bytes. */
if (original_nbytes <= sizeof(save)) {
memcpy(data, save, Py_MIN(nbytes, original_nbytes));
}
else {
size_t i = original_nbytes - ERASED_SIZE;
memcpy(data, save, Py_MIN(nbytes, ERASED_SIZE));
if (nbytes > i) {
memcpy(data + i, &save[ERASED_SIZE],
Py_MIN(nbytes - i, ERASED_SIZE));
}
}
#endif
if (r == NULL) {
return NULL;
}
if (nbytes > original_nbytes) {
/* growing: mark new extra memory clean */
memset(data + original_nbytes, PYMEM_CLEANBYTE,
nbytes - original_nbytes);
}
return data;
}
static inline void
_PyMem_DebugCheckGIL(const char *func)
{
if (!PyGILState_Check()) {
_Py_FatalErrorFunc(func,
"Python memory allocator called "
"without holding the GIL");
}
}
void *
_PyMem_DebugMalloc(void *ctx, size_t nbytes)
{
_PyMem_DebugCheckGIL(__func__);
return _PyMem_DebugRawMalloc(ctx, nbytes);
}
void *
_PyMem_DebugCalloc(void *ctx, size_t nelem, size_t elsize)
{
_PyMem_DebugCheckGIL(__func__);
return _PyMem_DebugRawCalloc(ctx, nelem, elsize);
}
void
_PyMem_DebugFree(void *ctx, void *ptr)
{
_PyMem_DebugCheckGIL(__func__);
_PyMem_DebugRawFree(ctx, ptr);
}
void *
_PyMem_DebugRealloc(void *ctx, void *ptr, size_t nbytes)
{
_PyMem_DebugCheckGIL(__func__);
return _PyMem_DebugRawRealloc(ctx, ptr, nbytes);
}
/* Check the forbidden bytes on both ends of the memory allocated for p.
* If anything is wrong, print info to stderr via _PyObject_DebugDumpAddress,
* and call Py_FatalError to kill the program.
* The API id, is also checked.
*/
static void
_PyMem_DebugCheckAddress(const char *func, char api, const void *p)
{
assert(p != NULL);
const uint8_t *q = (const uint8_t *)p;
size_t nbytes;
const uint8_t *tail;
int i;
char id;
/* Check the API id */
id = (char)q[-SST];
if (id != api) {
_PyObject_DebugDumpAddress(p);
_Py_FatalErrorFormat(func,
"bad ID: Allocated using API '%c', "
"verified using API '%c'",
id, api);
}
/* Check the stuff at the start of p first: if there's underwrite
* corruption, the number-of-bytes field may be nuts, and checking
* the tail could lead to a segfault then.
*/
for (i = SST-1; i >= 1; --i) {
if (*(q-i) != PYMEM_FORBIDDENBYTE) {
_PyObject_DebugDumpAddress(p);
_Py_FatalErrorFunc(func, "bad leading pad byte");
}
}
nbytes = read_size_t(q - 2*SST);
tail = q + nbytes;
for (i = 0; i < SST; ++i) {
if (tail[i] != PYMEM_FORBIDDENBYTE) {
_PyObject_DebugDumpAddress(p);
_Py_FatalErrorFunc(func, "bad trailing pad byte");
}
}
}
/* 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, " %zu 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 <= SST-1; ++i) {
if (*(q-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 = SST-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 #%zu 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 * %zd bytes each",
num_blocks, block_name, sizeof_block);
PyOS_snprintf(buf2, sizeof(buf2),
"%48s ", buf1);
(void)printone(out, buf2, num_blocks * sizeof_block);
}
// Return true if the obmalloc state structure is heap allocated,
// by PyMem_RawCalloc(). For the main interpreter, this structure
// allocated in the BSS. Allocating that way gives some memory savings
// and a small performance win (at least on a demand paged OS). On
// 64-bit platforms, the obmalloc structure is 256 kB. Most of that
// memory is for the arena_map_top array. Since normally only one entry
// of that array is used, only one page of resident memory is actually
// used, rather than the full 256 kB.
bool _PyMem_obmalloc_state_on_heap(PyInterpreterState *interp)
{
#if WITH_PYMALLOC
return interp->obmalloc && interp->obmalloc != &obmalloc_state_main;
#else
return false;
#endif
}
#ifdef WITH_PYMALLOC
static void
init_obmalloc_pools(PyInterpreterState *interp)
{
// initialize the obmalloc->pools structure. This must be done
// before the obmalloc alloc/free functions can be called.
poolp temp[OBMALLOC_USED_POOLS_SIZE] =
_obmalloc_pools_INIT(interp->obmalloc->pools);
memcpy(&interp->obmalloc->pools.used, temp, sizeof(temp));
}
#endif /* WITH_PYMALLOC */
int _PyMem_init_obmalloc(PyInterpreterState *interp)
{
#ifdef WITH_PYMALLOC
/* Initialize obmalloc, but only for subinterpreters,
since the main interpreter is initialized statically. */
if (_Py_IsMainInterpreter(interp)
|| _PyInterpreterState_HasFeature(interp,
Py_RTFLAGS_USE_MAIN_OBMALLOC)) {
interp->obmalloc = &obmalloc_state_main;
if (!obmalloc_state_initialized) {
init_obmalloc_pools(interp);
obmalloc_state_initialized = true;
}
} else {
interp->obmalloc = PyMem_RawCalloc(1, sizeof(struct _obmalloc_state));
if (interp->obmalloc == NULL) {
return -1;
}
init_obmalloc_pools(interp);
}
#endif /* WITH_PYMALLOC */
return 0; // success
}
#ifdef WITH_PYMALLOC
static void
free_obmalloc_arenas(PyInterpreterState *interp)
{
OMState *state = interp->obmalloc;
for (uint i = 0; i < maxarenas; ++i) {
// free each obmalloc memory arena
struct arena_object *ao = &allarenas[i];
_PyObject_Arena.free(_PyObject_Arena.ctx,
(void *)ao->address, ARENA_SIZE);
}
// free the array containing pointers to all arenas
PyMem_RawFree(allarenas);
#if WITH_PYMALLOC_RADIX_TREE
#ifdef USE_INTERIOR_NODES
// Free the middle and bottom nodes of the radix tree. These are allocated
// by arena_map_mark_used() but not freed when arenas are freed.
for (int i1 = 0; i1 < MAP_TOP_LENGTH; i1++) {
arena_map_mid_t *mid = arena_map_root.ptrs[i1];
if (mid == NULL) {
continue;
}
for (int i2 = 0; i2 < MAP_MID_LENGTH; i2++) {
arena_map_bot_t *bot = arena_map_root.ptrs[i1]->ptrs[i2];
if (bot == NULL) {
continue;
}
PyMem_RawFree(bot);
}
PyMem_RawFree(mid);
}
#endif
#endif
}
#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
#ifdef WITH_MIMALLOC
struct _alloc_stats {
size_t allocated_blocks;
size_t allocated_bytes;
size_t allocated_with_overhead;
size_t bytes_reserved;
size_t bytes_committed;
};
static bool _collect_alloc_stats(
const mi_heap_t* heap, const mi_heap_area_t* area,
void* block, size_t block_size, void* arg)
{
struct _alloc_stats *stats = (struct _alloc_stats *)arg;
stats->allocated_blocks += area->used;
stats->allocated_bytes += area->used * area->block_size;
stats->allocated_with_overhead += area->used * area->full_block_size;
stats->bytes_reserved += area->reserved;
stats->bytes_committed += area->committed;
return 1;
}
static void
py_mimalloc_print_stats(FILE *out)
{
fprintf(out, "Small block threshold = %zd, in %u size classes.\n",
MI_SMALL_OBJ_SIZE_MAX, MI_BIN_HUGE);
fprintf(out, "Medium block threshold = %zd\n",
MI_MEDIUM_OBJ_SIZE_MAX);
fprintf(out, "Large object max size = %zd\n",
MI_LARGE_OBJ_SIZE_MAX);
mi_heap_t *heap = mi_heap_get_default();
struct _alloc_stats stats;
memset(&stats, 0, sizeof(stats));
mi_heap_visit_blocks(heap, false, &_collect_alloc_stats, &stats);
fprintf(out, " Allocated Blocks: %zd\n", stats.allocated_blocks);
fprintf(out, " Allocated Bytes: %zd\n", stats.allocated_bytes);
fprintf(out, " Allocated Bytes w/ Overhead: %zd\n", stats.allocated_with_overhead);
fprintf(out, " Bytes Reserved: %zd\n", stats.bytes_reserved);
fprintf(out, " Bytes Committed: %zd\n", stats.bytes_committed);
}
#endif
static void
pymalloc_print_stats(FILE *out)
{
OMState *state = get_state();
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) {
uintptr_t base = allarenas[i].address;
/* Skip arenas which are not allocated. */
if (allarenas[i].address == (uintptr_t)NULL)
continue;
narenas += 1;
numfreepools += allarenas[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 <= (uintptr_t) allarenas[i].pool_address);
for (; base < (uintptr_t) allarenas[i].pool_address; base += POOL_SIZE) {
poolp p = (poolp)base;
const uint sz = p->szidx;
uint freeblocks;
if (p->ref.count == 0) {
/* currently unused */
#ifdef Py_DEBUG
assert(pool_is_in_list(p, allarenas[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 %11zu %15zu %13zu\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),
"%zu arenas * %d bytes/arena",
narenas, ARENA_SIZE);
(void)printone(out, buf, narenas * ARENA_SIZE);
fputc('\n', out);
/* Account for what all of those arena bytes are being used for. */
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);
assert(narenas * ARENA_SIZE == total);
#if WITH_PYMALLOC_RADIX_TREE
fputs("\narena map counts\n", out);
#ifdef USE_INTERIOR_NODES
(void)printone(out, "# arena map mid nodes", arena_map_mid_count);
(void)printone(out, "# arena map bot nodes", arena_map_bot_count);
fputc('\n', out);
#endif
total = printone(out, "# bytes lost to arena map root", sizeof(arena_map_root));
#ifdef USE_INTERIOR_NODES
total += printone(out, "# bytes lost to arena map mid",
sizeof(arena_map_mid_t) * arena_map_mid_count);
total += printone(out, "# bytes lost to arena map bot",
sizeof(arena_map_bot_t) * arena_map_bot_count);
(void)printone(out, "Total", total);
#endif
#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)
{
#ifdef WITH_MIMALLOC
if (_PyMem_MimallocEnabled()) {
py_mimalloc_print_stats(out);
return 1;
}
else
#endif
if (_PyMem_PymallocEnabled()) {
pymalloc_print_stats(out);
return 1;
}
else {
return 0;
}
}
#endif /* #ifdef WITH_PYMALLOC */
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