| #include "Python.h" |
| #include "pycore_pymem.h" // _PyTraceMalloc_Config |
| |
| #include <stdbool.h> |
| |
| |
| /* Defined in tracemalloc.c */ |
| extern void _PyMem_DumpTraceback(int fd, const void *ptr); |
| |
| |
| /* Python's malloc wrappers (see pymem.h) */ |
| |
| #undef uint |
| #define uint unsigned int /* assuming >= 16 bits */ |
| |
| /* Forward declaration */ |
| static void* _PyMem_DebugRawMalloc(void *ctx, size_t size); |
| static void* _PyMem_DebugRawCalloc(void *ctx, size_t nelem, size_t elsize); |
| static void* _PyMem_DebugRawRealloc(void *ctx, void *ptr, size_t size); |
| static void _PyMem_DebugRawFree(void *ctx, void *ptr); |
| |
| static void* _PyMem_DebugMalloc(void *ctx, size_t size); |
| static void* _PyMem_DebugCalloc(void *ctx, size_t nelem, size_t elsize); |
| static void* _PyMem_DebugRealloc(void *ctx, void *ptr, size_t size); |
| static void _PyMem_DebugFree(void *ctx, void *p); |
| |
| static void _PyObject_DebugDumpAddress(const void *p); |
| static void _PyMem_DebugCheckAddress(const char *func, char api_id, const void *p); |
| |
| static void _PyMem_SetupDebugHooksDomain(PyMemAllocatorDomain domain); |
| |
| #if defined(__has_feature) /* Clang */ |
| # if __has_feature(address_sanitizer) /* is ASAN enabled? */ |
| # define _Py_NO_SANITIZE_ADDRESS \ |
| __attribute__((no_sanitize("address"))) |
| # endif |
| # if __has_feature(thread_sanitizer) /* is TSAN enabled? */ |
| # define _Py_NO_SANITIZE_THREAD __attribute__((no_sanitize_thread)) |
| # endif |
| # if __has_feature(memory_sanitizer) /* is MSAN enabled? */ |
| # define _Py_NO_SANITIZE_MEMORY __attribute__((no_sanitize_memory)) |
| # endif |
| #elif defined(__GNUC__) |
| # if defined(__SANITIZE_ADDRESS__) /* GCC 4.8+, is ASAN enabled? */ |
| # define _Py_NO_SANITIZE_ADDRESS \ |
| __attribute__((no_sanitize_address)) |
| # endif |
| // TSAN is supported since GCC 5.1, but __SANITIZE_THREAD__ macro |
| // is provided only since GCC 7. |
| # if __GNUC__ > 5 || (__GNUC__ == 5 && __GNUC_MINOR__ >= 1) |
| # define _Py_NO_SANITIZE_THREAD __attribute__((no_sanitize_thread)) |
| # endif |
| #endif |
| |
| #ifndef _Py_NO_SANITIZE_ADDRESS |
| # define _Py_NO_SANITIZE_ADDRESS |
| #endif |
| #ifndef _Py_NO_SANITIZE_THREAD |
| # define _Py_NO_SANITIZE_THREAD |
| #endif |
| #ifndef _Py_NO_SANITIZE_MEMORY |
| # define _Py_NO_SANITIZE_MEMORY |
| #endif |
| |
| #ifdef WITH_PYMALLOC |
| |
| #ifdef MS_WINDOWS |
| # include <windows.h> |
| #elif defined(HAVE_MMAP) |
| # include <sys/mman.h> |
| # ifdef MAP_ANONYMOUS |
| # define ARENAS_USE_MMAP |
| # endif |
| #endif |
| |
| /* Forward declaration */ |
| static void* _PyObject_Malloc(void *ctx, size_t size); |
| static void* _PyObject_Calloc(void *ctx, size_t nelem, size_t elsize); |
| static void _PyObject_Free(void *ctx, void *p); |
| static void* _PyObject_Realloc(void *ctx, void *ptr, size_t size); |
| #endif |
| |
| |
| /* bpo-35053: Declare tracemalloc configuration here rather than |
| Modules/_tracemalloc.c because _tracemalloc can be compiled as dynamic |
| library, whereas _Py_NewReference() requires it. */ |
| struct _PyTraceMalloc_Config _Py_tracemalloc_config = _PyTraceMalloc_Config_INIT; |
| |
| |
| static void * |
| _PyMem_RawMalloc(void *ctx, size_t size) |
| { |
| /* PyMem_RawMalloc(0) means malloc(1). Some systems would return NULL |
| for malloc(0), which would be treated as an error. Some platforms would |
| return a pointer with no memory behind it, which would break pymalloc. |
| To solve these problems, allocate an extra byte. */ |
| if (size == 0) |
| size = 1; |
| return malloc(size); |
| } |
| |
| static void * |
| _PyMem_RawCalloc(void *ctx, size_t nelem, size_t elsize) |
| { |
| /* PyMem_RawCalloc(0, 0) means calloc(1, 1). Some systems would return NULL |
| for calloc(0, 0), which would be treated as an error. Some platforms |
| would return a pointer with no memory behind it, which would break |
| pymalloc. To solve these problems, allocate an extra byte. */ |
| if (nelem == 0 || elsize == 0) { |
| nelem = 1; |
| elsize = 1; |
| } |
| return calloc(nelem, elsize); |
| } |
| |
| static void * |
| _PyMem_RawRealloc(void *ctx, void *ptr, size_t size) |
| { |
| if (size == 0) |
| size = 1; |
| return realloc(ptr, size); |
| } |
| |
| static void |
| _PyMem_RawFree(void *ctx, void *ptr) |
| { |
| free(ptr); |
| } |
| |
| |
| #ifdef MS_WINDOWS |
| static void * |
| _PyObject_ArenaVirtualAlloc(void *ctx, size_t size) |
| { |
| return VirtualAlloc(NULL, size, |
| MEM_COMMIT | MEM_RESERVE, PAGE_READWRITE); |
| } |
| |
| static void |
| _PyObject_ArenaVirtualFree(void *ctx, void *ptr, size_t size) |
| { |
| VirtualFree(ptr, 0, MEM_RELEASE); |
| } |
| |
| #elif defined(ARENAS_USE_MMAP) |
| static void * |
| _PyObject_ArenaMmap(void *ctx, size_t size) |
| { |
| void *ptr; |
| ptr = mmap(NULL, size, PROT_READ|PROT_WRITE, |
| MAP_PRIVATE|MAP_ANONYMOUS, -1, 0); |
| if (ptr == MAP_FAILED) |
| return NULL; |
| assert(ptr != NULL); |
| return ptr; |
| } |
| |
| static void |
| _PyObject_ArenaMunmap(void *ctx, void *ptr, size_t size) |
| { |
| munmap(ptr, size); |
| } |
| |
| #else |
| static void * |
| _PyObject_ArenaMalloc(void *ctx, size_t size) |
| { |
| return malloc(size); |
| } |
| |
| static void |
| _PyObject_ArenaFree(void *ctx, void *ptr, size_t size) |
| { |
| free(ptr); |
| } |
| #endif |
| |
| #define MALLOC_ALLOC {NULL, _PyMem_RawMalloc, _PyMem_RawCalloc, _PyMem_RawRealloc, _PyMem_RawFree} |
| #ifdef WITH_PYMALLOC |
| # define PYMALLOC_ALLOC {NULL, _PyObject_Malloc, _PyObject_Calloc, _PyObject_Realloc, _PyObject_Free} |
| #endif |
| |
| #define PYRAW_ALLOC MALLOC_ALLOC |
| #ifdef WITH_PYMALLOC |
| # define PYOBJ_ALLOC PYMALLOC_ALLOC |
| #else |
| # define PYOBJ_ALLOC MALLOC_ALLOC |
| #endif |
| #define PYMEM_ALLOC PYOBJ_ALLOC |
| |
| typedef struct { |
| /* We tag each block with an API ID in order to tag API violations */ |
| char api_id; |
| PyMemAllocatorEx alloc; |
| } debug_alloc_api_t; |
| static struct { |
| debug_alloc_api_t raw; |
| debug_alloc_api_t mem; |
| debug_alloc_api_t obj; |
| } _PyMem_Debug = { |
| {'r', PYRAW_ALLOC}, |
| {'m', PYMEM_ALLOC}, |
| {'o', PYOBJ_ALLOC} |
| }; |
| |
| #define PYDBGRAW_ALLOC \ |
| {&_PyMem_Debug.raw, _PyMem_DebugRawMalloc, _PyMem_DebugRawCalloc, _PyMem_DebugRawRealloc, _PyMem_DebugRawFree} |
| #define PYDBGMEM_ALLOC \ |
| {&_PyMem_Debug.mem, _PyMem_DebugMalloc, _PyMem_DebugCalloc, _PyMem_DebugRealloc, _PyMem_DebugFree} |
| #define PYDBGOBJ_ALLOC \ |
| {&_PyMem_Debug.obj, _PyMem_DebugMalloc, _PyMem_DebugCalloc, _PyMem_DebugRealloc, _PyMem_DebugFree} |
| |
| #ifdef Py_DEBUG |
| static PyMemAllocatorEx _PyMem_Raw = PYDBGRAW_ALLOC; |
| static PyMemAllocatorEx _PyMem = PYDBGMEM_ALLOC; |
| static PyMemAllocatorEx _PyObject = PYDBGOBJ_ALLOC; |
| #else |
| static PyMemAllocatorEx _PyMem_Raw = PYRAW_ALLOC; |
| static PyMemAllocatorEx _PyMem = PYMEM_ALLOC; |
| static PyMemAllocatorEx _PyObject = PYOBJ_ALLOC; |
| #endif |
| |
| |
| static int |
| pymem_set_default_allocator(PyMemAllocatorDomain domain, int debug, |
| PyMemAllocatorEx *old_alloc) |
| { |
| if (old_alloc != NULL) { |
| PyMem_GetAllocator(domain, old_alloc); |
| } |
| |
| |
| PyMemAllocatorEx new_alloc; |
| switch(domain) |
| { |
| case PYMEM_DOMAIN_RAW: |
| new_alloc = (PyMemAllocatorEx)PYRAW_ALLOC; |
| break; |
| case PYMEM_DOMAIN_MEM: |
| new_alloc = (PyMemAllocatorEx)PYMEM_ALLOC; |
| break; |
| case PYMEM_DOMAIN_OBJ: |
| new_alloc = (PyMemAllocatorEx)PYOBJ_ALLOC; |
| break; |
| default: |
| /* unknown domain */ |
| return -1; |
| } |
| PyMem_SetAllocator(domain, &new_alloc); |
| if (debug) { |
| _PyMem_SetupDebugHooksDomain(domain); |
| } |
| return 0; |
| } |
| |
| |
| int |
| _PyMem_SetDefaultAllocator(PyMemAllocatorDomain domain, |
| PyMemAllocatorEx *old_alloc) |
| { |
| #ifdef Py_DEBUG |
| const int debug = 1; |
| #else |
| const int debug = 0; |
| #endif |
| return pymem_set_default_allocator(domain, debug, old_alloc); |
| } |
| |
| |
| int |
| _PyMem_GetAllocatorName(const char *name, PyMemAllocatorName *allocator) |
| { |
| if (name == NULL || *name == '\0') { |
| /* PYTHONMALLOC is empty or is not set or ignored (-E/-I command line |
| nameions): use default memory allocators */ |
| *allocator = PYMEM_ALLOCATOR_DEFAULT; |
| } |
| else if (strcmp(name, "default") == 0) { |
| *allocator = PYMEM_ALLOCATOR_DEFAULT; |
| } |
| else if (strcmp(name, "debug") == 0) { |
| *allocator = PYMEM_ALLOCATOR_DEBUG; |
| } |
| #ifdef WITH_PYMALLOC |
| else if (strcmp(name, "pymalloc") == 0) { |
| *allocator = PYMEM_ALLOCATOR_PYMALLOC; |
| } |
| else if (strcmp(name, "pymalloc_debug") == 0) { |
| *allocator = PYMEM_ALLOCATOR_PYMALLOC_DEBUG; |
| } |
| #endif |
| else if (strcmp(name, "malloc") == 0) { |
| *allocator = PYMEM_ALLOCATOR_MALLOC; |
| } |
| else if (strcmp(name, "malloc_debug") == 0) { |
| *allocator = PYMEM_ALLOCATOR_MALLOC_DEBUG; |
| } |
| else { |
| /* unknown allocator */ |
| return -1; |
| } |
| return 0; |
| } |
| |
| |
| int |
| _PyMem_SetupAllocators(PyMemAllocatorName allocator) |
| { |
| switch (allocator) { |
| case PYMEM_ALLOCATOR_NOT_SET: |
| /* do nothing */ |
| break; |
| |
| case PYMEM_ALLOCATOR_DEFAULT: |
| (void)_PyMem_SetDefaultAllocator(PYMEM_DOMAIN_RAW, NULL); |
| (void)_PyMem_SetDefaultAllocator(PYMEM_DOMAIN_MEM, NULL); |
| (void)_PyMem_SetDefaultAllocator(PYMEM_DOMAIN_OBJ, NULL); |
| break; |
| |
| case PYMEM_ALLOCATOR_DEBUG: |
| (void)pymem_set_default_allocator(PYMEM_DOMAIN_RAW, 1, NULL); |
| (void)pymem_set_default_allocator(PYMEM_DOMAIN_MEM, 1, NULL); |
| (void)pymem_set_default_allocator(PYMEM_DOMAIN_OBJ, 1, NULL); |
| break; |
| |
| #ifdef WITH_PYMALLOC |
| case PYMEM_ALLOCATOR_PYMALLOC: |
| case PYMEM_ALLOCATOR_PYMALLOC_DEBUG: |
| { |
| PyMemAllocatorEx malloc_alloc = MALLOC_ALLOC; |
| PyMem_SetAllocator(PYMEM_DOMAIN_RAW, &malloc_alloc); |
| |
| PyMemAllocatorEx pymalloc = PYMALLOC_ALLOC; |
| PyMem_SetAllocator(PYMEM_DOMAIN_MEM, &pymalloc); |
| PyMem_SetAllocator(PYMEM_DOMAIN_OBJ, &pymalloc); |
| |
| if (allocator == PYMEM_ALLOCATOR_PYMALLOC_DEBUG) { |
| PyMem_SetupDebugHooks(); |
| } |
| break; |
| } |
| #endif |
| |
| case PYMEM_ALLOCATOR_MALLOC: |
| case PYMEM_ALLOCATOR_MALLOC_DEBUG: |
| { |
| PyMemAllocatorEx malloc_alloc = MALLOC_ALLOC; |
| PyMem_SetAllocator(PYMEM_DOMAIN_RAW, &malloc_alloc); |
| PyMem_SetAllocator(PYMEM_DOMAIN_MEM, &malloc_alloc); |
| PyMem_SetAllocator(PYMEM_DOMAIN_OBJ, &malloc_alloc); |
| |
| if (allocator == PYMEM_ALLOCATOR_MALLOC_DEBUG) { |
| PyMem_SetupDebugHooks(); |
| } |
| break; |
| } |
| |
| default: |
| /* unknown allocator */ |
| return -1; |
| } |
| return 0; |
| } |
| |
| |
| static int |
| pymemallocator_eq(PyMemAllocatorEx *a, PyMemAllocatorEx *b) |
| { |
| return (memcmp(a, b, sizeof(PyMemAllocatorEx)) == 0); |
| } |
| |
| |
| const char* |
| _PyMem_GetCurrentAllocatorName(void) |
| { |
| PyMemAllocatorEx malloc_alloc = MALLOC_ALLOC; |
| #ifdef WITH_PYMALLOC |
| PyMemAllocatorEx pymalloc = PYMALLOC_ALLOC; |
| #endif |
| |
| if (pymemallocator_eq(&_PyMem_Raw, &malloc_alloc) && |
| pymemallocator_eq(&_PyMem, &malloc_alloc) && |
| pymemallocator_eq(&_PyObject, &malloc_alloc)) |
| { |
| return "malloc"; |
| } |
| #ifdef WITH_PYMALLOC |
| if (pymemallocator_eq(&_PyMem_Raw, &malloc_alloc) && |
| pymemallocator_eq(&_PyMem, &pymalloc) && |
| pymemallocator_eq(&_PyObject, &pymalloc)) |
| { |
| return "pymalloc"; |
| } |
| #endif |
| |
| PyMemAllocatorEx dbg_raw = PYDBGRAW_ALLOC; |
| PyMemAllocatorEx dbg_mem = PYDBGMEM_ALLOC; |
| PyMemAllocatorEx dbg_obj = PYDBGOBJ_ALLOC; |
| |
| if (pymemallocator_eq(&_PyMem_Raw, &dbg_raw) && |
| pymemallocator_eq(&_PyMem, &dbg_mem) && |
| pymemallocator_eq(&_PyObject, &dbg_obj)) |
| { |
| /* Debug hooks installed */ |
| if (pymemallocator_eq(&_PyMem_Debug.raw.alloc, &malloc_alloc) && |
| pymemallocator_eq(&_PyMem_Debug.mem.alloc, &malloc_alloc) && |
| pymemallocator_eq(&_PyMem_Debug.obj.alloc, &malloc_alloc)) |
| { |
| return "malloc_debug"; |
| } |
| #ifdef WITH_PYMALLOC |
| if (pymemallocator_eq(&_PyMem_Debug.raw.alloc, &malloc_alloc) && |
| pymemallocator_eq(&_PyMem_Debug.mem.alloc, &pymalloc) && |
| pymemallocator_eq(&_PyMem_Debug.obj.alloc, &pymalloc)) |
| { |
| return "pymalloc_debug"; |
| } |
| #endif |
| } |
| return NULL; |
| } |
| |
| |
| #undef MALLOC_ALLOC |
| #undef PYMALLOC_ALLOC |
| #undef PYRAW_ALLOC |
| #undef PYMEM_ALLOC |
| #undef PYOBJ_ALLOC |
| #undef PYDBGRAW_ALLOC |
| #undef PYDBGMEM_ALLOC |
| #undef PYDBGOBJ_ALLOC |
| |
| |
| static PyObjectArenaAllocator _PyObject_Arena = {NULL, |
| #ifdef MS_WINDOWS |
| _PyObject_ArenaVirtualAlloc, _PyObject_ArenaVirtualFree |
| #elif defined(ARENAS_USE_MMAP) |
| _PyObject_ArenaMmap, _PyObject_ArenaMunmap |
| #else |
| _PyObject_ArenaMalloc, _PyObject_ArenaFree |
| #endif |
| }; |
| |
| #ifdef WITH_PYMALLOC |
| static int |
| _PyMem_DebugEnabled(void) |
| { |
| return (_PyObject.malloc == _PyMem_DebugMalloc); |
| } |
| |
| static int |
| _PyMem_PymallocEnabled(void) |
| { |
| if (_PyMem_DebugEnabled()) { |
| return (_PyMem_Debug.obj.alloc.malloc == _PyObject_Malloc); |
| } |
| else { |
| return (_PyObject.malloc == _PyObject_Malloc); |
| } |
| } |
| #endif |
| |
| |
| static void |
| _PyMem_SetupDebugHooksDomain(PyMemAllocatorDomain domain) |
| { |
| PyMemAllocatorEx alloc; |
| |
| if (domain == PYMEM_DOMAIN_RAW) { |
| if (_PyMem_Raw.malloc == _PyMem_DebugRawMalloc) { |
| return; |
| } |
| |
| PyMem_GetAllocator(PYMEM_DOMAIN_RAW, &_PyMem_Debug.raw.alloc); |
| alloc.ctx = &_PyMem_Debug.raw; |
| alloc.malloc = _PyMem_DebugRawMalloc; |
| alloc.calloc = _PyMem_DebugRawCalloc; |
| alloc.realloc = _PyMem_DebugRawRealloc; |
| alloc.free = _PyMem_DebugRawFree; |
| PyMem_SetAllocator(PYMEM_DOMAIN_RAW, &alloc); |
| } |
| else if (domain == PYMEM_DOMAIN_MEM) { |
| if (_PyMem.malloc == _PyMem_DebugMalloc) { |
| return; |
| } |
| |
| PyMem_GetAllocator(PYMEM_DOMAIN_MEM, &_PyMem_Debug.mem.alloc); |
| alloc.ctx = &_PyMem_Debug.mem; |
| alloc.malloc = _PyMem_DebugMalloc; |
| alloc.calloc = _PyMem_DebugCalloc; |
| alloc.realloc = _PyMem_DebugRealloc; |
| alloc.free = _PyMem_DebugFree; |
| PyMem_SetAllocator(PYMEM_DOMAIN_MEM, &alloc); |
| } |
| else if (domain == PYMEM_DOMAIN_OBJ) { |
| if (_PyObject.malloc == _PyMem_DebugMalloc) { |
| return; |
| } |
| |
| PyMem_GetAllocator(PYMEM_DOMAIN_OBJ, &_PyMem_Debug.obj.alloc); |
| alloc.ctx = &_PyMem_Debug.obj; |
| alloc.malloc = _PyMem_DebugMalloc; |
| alloc.calloc = _PyMem_DebugCalloc; |
| alloc.realloc = _PyMem_DebugRealloc; |
| alloc.free = _PyMem_DebugFree; |
| PyMem_SetAllocator(PYMEM_DOMAIN_OBJ, &alloc); |
| } |
| } |
| |
| |
| void |
| PyMem_SetupDebugHooks(void) |
| { |
| _PyMem_SetupDebugHooksDomain(PYMEM_DOMAIN_RAW); |
| _PyMem_SetupDebugHooksDomain(PYMEM_DOMAIN_MEM); |
| _PyMem_SetupDebugHooksDomain(PYMEM_DOMAIN_OBJ); |
| } |
| |
| void |
| PyMem_GetAllocator(PyMemAllocatorDomain domain, PyMemAllocatorEx *allocator) |
| { |
| switch(domain) |
| { |
| case PYMEM_DOMAIN_RAW: *allocator = _PyMem_Raw; break; |
| case PYMEM_DOMAIN_MEM: *allocator = _PyMem; break; |
| case PYMEM_DOMAIN_OBJ: *allocator = _PyObject; break; |
| default: |
| /* unknown domain: set all attributes to NULL */ |
| allocator->ctx = NULL; |
| allocator->malloc = NULL; |
| allocator->calloc = NULL; |
| allocator->realloc = NULL; |
| allocator->free = NULL; |
| } |
| } |
| |
| void |
| PyMem_SetAllocator(PyMemAllocatorDomain domain, PyMemAllocatorEx *allocator) |
| { |
| switch(domain) |
| { |
| case PYMEM_DOMAIN_RAW: _PyMem_Raw = *allocator; break; |
| case PYMEM_DOMAIN_MEM: _PyMem = *allocator; break; |
| case PYMEM_DOMAIN_OBJ: _PyObject = *allocator; break; |
| /* ignore unknown domain */ |
| } |
| } |
| |
| void |
| PyObject_GetArenaAllocator(PyObjectArenaAllocator *allocator) |
| { |
| *allocator = _PyObject_Arena; |
| } |
| |
| void |
| PyObject_SetArenaAllocator(PyObjectArenaAllocator *allocator) |
| { |
| _PyObject_Arena = *allocator; |
| } |
| |
| void * |
| PyMem_RawMalloc(size_t size) |
| { |
| /* |
| * Limit ourselves to PY_SSIZE_T_MAX bytes to prevent security holes. |
| * Most python internals blindly use a signed Py_ssize_t to track |
| * things without checking for overflows or negatives. |
| * As size_t is unsigned, checking for size < 0 is not required. |
| */ |
| if (size > (size_t)PY_SSIZE_T_MAX) |
| return NULL; |
| return _PyMem_Raw.malloc(_PyMem_Raw.ctx, size); |
| } |
| |
| void * |
| PyMem_RawCalloc(size_t nelem, size_t elsize) |
| { |
| /* see PyMem_RawMalloc() */ |
| if (elsize != 0 && nelem > (size_t)PY_SSIZE_T_MAX / elsize) |
| return NULL; |
| return _PyMem_Raw.calloc(_PyMem_Raw.ctx, nelem, elsize); |
| } |
| |
| void* |
| PyMem_RawRealloc(void *ptr, size_t new_size) |
| { |
| /* see PyMem_RawMalloc() */ |
| if (new_size > (size_t)PY_SSIZE_T_MAX) |
| return NULL; |
| return _PyMem_Raw.realloc(_PyMem_Raw.ctx, ptr, new_size); |
| } |
| |
| void PyMem_RawFree(void *ptr) |
| { |
| _PyMem_Raw.free(_PyMem_Raw.ctx, ptr); |
| } |
| |
| |
| void * |
| PyMem_Malloc(size_t size) |
| { |
| /* see PyMem_RawMalloc() */ |
| if (size > (size_t)PY_SSIZE_T_MAX) |
| return NULL; |
| return _PyMem.malloc(_PyMem.ctx, size); |
| } |
| |
| void * |
| PyMem_Calloc(size_t nelem, size_t elsize) |
| { |
| /* see PyMem_RawMalloc() */ |
| if (elsize != 0 && nelem > (size_t)PY_SSIZE_T_MAX / elsize) |
| return NULL; |
| return _PyMem.calloc(_PyMem.ctx, nelem, elsize); |
| } |
| |
| void * |
| PyMem_Realloc(void *ptr, size_t new_size) |
| { |
| /* see PyMem_RawMalloc() */ |
| if (new_size > (size_t)PY_SSIZE_T_MAX) |
| return NULL; |
| return _PyMem.realloc(_PyMem.ctx, ptr, new_size); |
| } |
| |
| void |
| PyMem_Free(void *ptr) |
| { |
| _PyMem.free(_PyMem.ctx, ptr); |
| } |
| |
| |
| wchar_t* |
| _PyMem_RawWcsdup(const wchar_t *str) |
| { |
| assert(str != NULL); |
| |
| size_t len = wcslen(str); |
| if (len > (size_t)PY_SSIZE_T_MAX / sizeof(wchar_t) - 1) { |
| return NULL; |
| } |
| |
| size_t size = (len + 1) * sizeof(wchar_t); |
| wchar_t *str2 = PyMem_RawMalloc(size); |
| if (str2 == NULL) { |
| return NULL; |
| } |
| |
| memcpy(str2, str, size); |
| return str2; |
| } |
| |
| char * |
| _PyMem_RawStrdup(const char *str) |
| { |
| assert(str != NULL); |
| size_t size = strlen(str) + 1; |
| char *copy = PyMem_RawMalloc(size); |
| if (copy == NULL) { |
| return NULL; |
| } |
| memcpy(copy, str, size); |
| return copy; |
| } |
| |
| char * |
| _PyMem_Strdup(const char *str) |
| { |
| assert(str != NULL); |
| size_t size = strlen(str) + 1; |
| char *copy = PyMem_Malloc(size); |
| if (copy == NULL) { |
| return NULL; |
| } |
| memcpy(copy, str, size); |
| return copy; |
| } |
| |
| void * |
| PyObject_Malloc(size_t size) |
| { |
| /* see PyMem_RawMalloc() */ |
| if (size > (size_t)PY_SSIZE_T_MAX) |
| return NULL; |
| return _PyObject.malloc(_PyObject.ctx, size); |
| } |
| |
| void * |
| PyObject_Calloc(size_t nelem, size_t elsize) |
| { |
| /* see PyMem_RawMalloc() */ |
| if (elsize != 0 && nelem > (size_t)PY_SSIZE_T_MAX / elsize) |
| return NULL; |
| return _PyObject.calloc(_PyObject.ctx, nelem, elsize); |
| } |
| |
| void * |
| PyObject_Realloc(void *ptr, size_t new_size) |
| { |
| /* see PyMem_RawMalloc() */ |
| if (new_size > (size_t)PY_SSIZE_T_MAX) |
| return NULL; |
| return _PyObject.realloc(_PyObject.ctx, ptr, new_size); |
| } |
| |
| void |
| PyObject_Free(void *ptr) |
| { |
| _PyObject.free(_PyObject.ctx, ptr); |
| } |
| |
| |
| /* 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 |
| |
| |
| /* An object allocator for Python. |
| |
| Here is an introduction to the layers of the Python memory architecture, |
| showing where the object allocator is actually used (layer +2), It is |
| called for every object allocation and deallocation (PyObject_New/Del), |
| unless the object-specific allocators implement a proprietary allocation |
| scheme (ex.: ints use a simple free list). This is also the place where |
| the cyclic garbage collector operates selectively on container objects. |
| |
| |
| Object-specific allocators |
| _____ ______ ______ ________ |
| [ int ] [ dict ] [ list ] ... [ string ] Python core | |
| +3 | <----- Object-specific memory -----> | <-- Non-object memory --> | |
| _______________________________ | | |
| [ Python's object allocator ] | | |
| +2 | ####### Object memory ####### | <------ Internal buffers ------> | |
| ______________________________________________________________ | |
| [ Python's raw memory allocator (PyMem_ API) ] | |
| +1 | <----- Python memory (under PyMem manager's control) ------> | | |
| __________________________________________________________________ |
| [ Underlying general-purpose allocator (ex: C library malloc) ] |
| 0 | <------ Virtual memory allocated for the python process -------> | |
| |
| ========================================================================= |
| _______________________________________________________________________ |
| [ OS-specific Virtual Memory Manager (VMM) ] |
| -1 | <--- Kernel dynamic storage allocation & management (page-based) ---> | |
| __________________________________ __________________________________ |
| [ ] [ ] |
| -2 | <-- Physical memory: ROM/RAM --> | | <-- Secondary storage (swap) --> | |
| |
| */ |
| /*==========================================================================*/ |
| |
| /* A fast, special-purpose memory allocator for small blocks, to be used |
| on top of a general-purpose malloc -- heavily based on previous art. */ |
| |
| /* Vladimir Marangozov -- August 2000 */ |
| |
| /* |
| * "Memory management is where the rubber meets the road -- if we do the wrong |
| * thing at any level, the results will not be good. And if we don't make the |
| * levels work well together, we are in serious trouble." (1) |
| * |
| * (1) Paul R. Wilson, Mark S. Johnstone, Michael Neely, and David Boles, |
| * "Dynamic Storage Allocation: A Survey and Critical Review", |
| * in Proc. 1995 Int'l. Workshop on Memory Management, September 1995. |
| */ |
| |
| /* #undef WITH_MEMORY_LIMITS */ /* disable mem limit checks */ |
| |
| /*==========================================================================*/ |
| |
| /* |
| * Allocation strategy abstract: |
| * |
| * For small requests, the allocator sub-allocates <Big> blocks of memory. |
| * Requests greater than SMALL_REQUEST_THRESHOLD bytes are routed to the |
| * system's allocator. |
| * |
| * Small requests are grouped in size classes spaced 8 bytes apart, due |
| * to the required valid alignment of the returned address. Requests of |
| * a particular size are serviced from memory pools of 4K (one VMM page). |
| * Pools are fragmented on demand and contain free lists of blocks of one |
| * particular size class. In other words, there is a fixed-size allocator |
| * for each size class. Free pools are shared by the different allocators |
| * thus minimizing the space reserved for a particular size class. |
| * |
| * This allocation strategy is a variant of what is known as "simple |
| * segregated storage based on array of free lists". The main drawback of |
| * simple segregated storage is that we might end up with lot of reserved |
| * memory for the different free lists, which degenerate in time. To avoid |
| * this, we partition each free list in pools and we share dynamically the |
| * reserved space between all free lists. This technique is quite efficient |
| * for memory intensive programs which allocate mainly small-sized blocks. |
| * |
| * For small requests we have the following table: |
| * |
| * Request in bytes Size of allocated block Size class idx |
| * ---------------------------------------------------------------- |
| * 1-8 8 0 |
| * 9-16 16 1 |
| * 17-24 24 2 |
| * 25-32 32 3 |
| * 33-40 40 4 |
| * 41-48 48 5 |
| * 49-56 56 6 |
| * 57-64 64 7 |
| * 65-72 72 8 |
| * ... ... ... |
| * 497-504 504 62 |
| * 505-512 512 63 |
| * |
| * 0, SMALL_REQUEST_THRESHOLD + 1 and up: routed to the underlying |
| * allocator. |
| */ |
| |
| /*==========================================================================*/ |
| |
| /* |
| * -- Main tunable settings section -- |
| */ |
| |
| /* |
| * Alignment of addresses returned to the user. 8-bytes alignment works |
| * on most current architectures (with 32-bit or 64-bit address busses). |
| * The alignment value is also used for grouping small requests in size |
| * classes spaced ALIGNMENT bytes apart. |
| * |
| * You shouldn't change this unless you know what you are doing. |
| */ |
| |
| #if SIZEOF_VOID_P > 4 |
| #define ALIGNMENT 16 /* must be 2^N */ |
| #define ALIGNMENT_SHIFT 4 |
| #else |
| #define ALIGNMENT 8 /* must be 2^N */ |
| #define ALIGNMENT_SHIFT 3 |
| #endif |
| |
| /* Return the number of bytes in size class I, as a uint. */ |
| #define INDEX2SIZE(I) (((uint)(I) + 1) << ALIGNMENT_SHIFT) |
| |
| /* |
| * Max size threshold below which malloc requests are considered to be |
| * small enough in order to use preallocated memory pools. You can tune |
| * this value according to your application behaviour and memory needs. |
| * |
| * Note: a size threshold of 512 guarantees that newly created dictionaries |
| * will be allocated from preallocated memory pools on 64-bit. |
| * |
| * The following invariants must hold: |
| * 1) ALIGNMENT <= SMALL_REQUEST_THRESHOLD <= 512 |
| * 2) SMALL_REQUEST_THRESHOLD is evenly divisible by ALIGNMENT |
| * |
| * Although not required, for better performance and space efficiency, |
| * it is recommended that SMALL_REQUEST_THRESHOLD is set to a power of 2. |
| */ |
| #define SMALL_REQUEST_THRESHOLD 512 |
| #define NB_SMALL_SIZE_CLASSES (SMALL_REQUEST_THRESHOLD / ALIGNMENT) |
| |
| /* |
| * The system's VMM page size can be obtained on most unices with a |
| * getpagesize() call or deduced from various header files. To make |
| * things simpler, we assume that it is 4K, which is OK for most systems. |
| * It is probably better if this is the native page size, but it doesn't |
| * have to be. In theory, if SYSTEM_PAGE_SIZE is larger than the native page |
| * size, then `POOL_ADDR(p)->arenaindex' could rarely cause a segmentation |
| * violation fault. 4K is apparently OK for all the platforms that python |
| * currently targets. |
| */ |
| #define SYSTEM_PAGE_SIZE (4 * 1024) |
| #define SYSTEM_PAGE_SIZE_MASK (SYSTEM_PAGE_SIZE - 1) |
| |
| /* |
| * Maximum amount of memory managed by the allocator for small requests. |
| */ |
| #ifdef WITH_MEMORY_LIMITS |
| #ifndef SMALL_MEMORY_LIMIT |
| #define SMALL_MEMORY_LIMIT (64 * 1024 * 1024) /* 64 MB -- more? */ |
| #endif |
| #endif |
| |
| /* |
| * The allocator sub-allocates <Big> blocks of memory (called arenas) aligned |
| * on a page boundary. This is a reserved virtual address space for the |
| * current process (obtained through a malloc()/mmap() call). In no way this |
| * means that the memory arenas will be used entirely. A malloc(<Big>) is |
| * usually an address range reservation for <Big> bytes, unless all pages within |
| * this space are referenced subsequently. So malloc'ing big blocks and not |
| * using them does not mean "wasting memory". It's an addressable range |
| * wastage... |
| * |
| * Arenas are allocated with mmap() on systems supporting anonymous memory |
| * mappings to reduce heap fragmentation. |
| */ |
| #define ARENA_SIZE (256 << 10) /* 256KB */ |
| |
| #ifdef WITH_MEMORY_LIMITS |
| #define MAX_ARENAS (SMALL_MEMORY_LIMIT / ARENA_SIZE) |
| #endif |
| |
| /* |
| * Size of the pools used for small blocks. Should be a power of 2, |
| * between 1K and SYSTEM_PAGE_SIZE, that is: 1k, 2k, 4k. |
| */ |
| #define POOL_SIZE SYSTEM_PAGE_SIZE /* must be 2^N */ |
| #define POOL_SIZE_MASK SYSTEM_PAGE_SIZE_MASK |
| |
| #define MAX_POOLS_IN_ARENA (ARENA_SIZE / POOL_SIZE) |
| #if MAX_POOLS_IN_ARENA * POOL_SIZE != ARENA_SIZE |
| # error "arena size not an exact multiple of pool size" |
| #endif |
| |
| /* |
| * -- End of tunable settings section -- |
| */ |
| |
| /*==========================================================================*/ |
| |
| /* When you say memory, my mind reasons in terms of (pointers to) blocks */ |
| typedef uint8_t block; |
| |
| /* Pool for small blocks. */ |
| struct pool_header { |
| union { block *_padding; |
| uint count; } ref; /* number of allocated blocks */ |
| block *freeblock; /* pool's free list head */ |
| struct pool_header *nextpool; /* next pool of this size class */ |
| struct pool_header *prevpool; /* previous pool "" */ |
| uint arenaindex; /* index into arenas of base adr */ |
| uint szidx; /* block size class index */ |
| uint nextoffset; /* bytes to virgin block */ |
| uint maxnextoffset; /* largest valid nextoffset */ |
| }; |
| |
| typedef struct pool_header *poolp; |
| |
| /* Record keeping for arenas. */ |
| struct arena_object { |
| /* The address of the arena, as returned by malloc. Note that 0 |
| * will never be returned by a successful malloc, and is used |
| * here to mark an arena_object that doesn't correspond to an |
| * allocated arena. |
| */ |
| uintptr_t address; |
| |
| /* Pool-aligned pointer to the next pool to be carved off. */ |
| block* pool_address; |
| |
| /* The number of available pools in the arena: free pools + never- |
| * allocated pools. |
| */ |
| uint nfreepools; |
| |
| /* The total number of pools in the arena, whether or not available. */ |
| uint ntotalpools; |
| |
| /* Singly-linked list of available pools. */ |
| struct pool_header* freepools; |
| |
| /* Whenever this arena_object is not associated with an allocated |
| * arena, the nextarena member is used to link all unassociated |
| * arena_objects in the singly-linked `unused_arena_objects` list. |
| * The prevarena member is unused in this case. |
| * |
| * When this arena_object is associated with an allocated arena |
| * with at least one available pool, both members are used in the |
| * doubly-linked `usable_arenas` list, which is maintained in |
| * increasing order of `nfreepools` values. |
| * |
| * Else this arena_object is associated with an allocated arena |
| * all of whose pools are in use. `nextarena` and `prevarena` |
| * are both meaningless in this case. |
| */ |
| struct arena_object* nextarena; |
| struct arena_object* prevarena; |
| }; |
| |
| #define POOL_OVERHEAD _Py_SIZE_ROUND_UP(sizeof(struct pool_header), ALIGNMENT) |
| |
| #define DUMMY_SIZE_IDX 0xffff /* size class of newly cached pools */ |
| |
| /* Round pointer P down to the closest pool-aligned address <= P, as a poolp */ |
| #define POOL_ADDR(P) ((poolp)_Py_ALIGN_DOWN((P), POOL_SIZE)) |
| |
| /* Return total number of blocks in pool of size index I, as a uint. */ |
| #define NUMBLOCKS(I) ((uint)(POOL_SIZE - POOL_OVERHEAD) / INDEX2SIZE(I)) |
| |
| /*==========================================================================*/ |
| |
| /* |
| * Pool table -- headed, circular, doubly-linked lists of partially used pools. |
| |
| This is involved. For an index i, usedpools[i+i] is the header for a list of |
| all partially used pools holding small blocks with "size class idx" i. So |
| usedpools[0] corresponds to blocks of size 8, usedpools[2] to blocks of size |
| 16, and so on: index 2*i <-> blocks of size (i+1)<<ALIGNMENT_SHIFT. |
| |
| Pools are carved off an arena's highwater mark (an arena_object's pool_address |
| member) as needed. Once carved off, a pool is in one of three states forever |
| after: |
| |
| used == partially used, neither empty nor full |
| At least one block in the pool is currently allocated, and at least one |
| block in the pool is not currently allocated (note this implies a pool |
| has room for at least two blocks). |
| This is a pool's initial state, as a pool is created only when malloc |
| needs space. |
| The pool holds blocks of a fixed size, and is in the circular list headed |
| at usedpools[i] (see above). It's linked to the other used pools of the |
| same size class via the pool_header's nextpool and prevpool members. |
| If all but one block is currently allocated, a malloc can cause a |
| transition to the full state. If all but one block is not currently |
| allocated, a free can cause a transition to the empty state. |
| |
| full == all the pool's blocks are currently allocated |
| On transition to full, a pool is unlinked from its usedpools[] list. |
| It's not linked to from anything then anymore, and its nextpool and |
| prevpool members are meaningless until it transitions back to used. |
| A free of a block in a full pool puts the pool back in the used state. |
| Then it's linked in at the front of the appropriate usedpools[] list, so |
| that the next allocation for its size class will reuse the freed block. |
| |
| empty == all the pool's blocks are currently available for allocation |
| On transition to empty, a pool is unlinked from its usedpools[] list, |
| and linked to the front of its arena_object's singly-linked freepools list, |
| via its nextpool member. The prevpool member has no meaning in this case. |
| Empty pools have no inherent size class: the next time a malloc finds |
| an empty list in usedpools[], it takes the first pool off of freepools. |
| If the size class needed happens to be the same as the size class the pool |
| last had, some pool initialization can be skipped. |
| |
| |
| Block Management |
| |
| Blocks within pools are again carved out as needed. pool->freeblock points to |
| the start of a singly-linked list of free blocks within the pool. When a |
| block is freed, it's inserted at the front of its pool's freeblock list. Note |
| that the available blocks in a pool are *not* linked all together when a pool |
| is initialized. Instead only "the first two" (lowest addresses) blocks are |
| set up, returning the first such block, and setting pool->freeblock to a |
| one-block list holding the second such block. This is consistent with that |
| pymalloc strives at all levels (arena, pool, and block) never to touch a piece |
| of memory until it's actually needed. |
| |
| So long as a pool is in the used state, we're certain there *is* a block |
| available for allocating, and pool->freeblock is not NULL. If pool->freeblock |
| points to the end of the free list before we've carved the entire pool into |
| blocks, that means we simply haven't yet gotten to one of the higher-address |
| blocks. The offset from the pool_header to the start of "the next" virgin |
| block is stored in the pool_header nextoffset member, and the largest value |
| of nextoffset that makes sense is stored in the maxnextoffset member when a |
| pool is initialized. All the blocks in a pool have been passed out at least |
| once when and only when nextoffset > maxnextoffset. |
| |
| |
| Major obscurity: While the usedpools vector is declared to have poolp |
| entries, it doesn't really. It really contains two pointers per (conceptual) |
| poolp entry, the nextpool and prevpool members of a pool_header. The |
| excruciating initialization code below fools C so that |
| |
| usedpool[i+i] |
| |
| "acts like" a genuine poolp, but only so long as you only reference its |
| nextpool and prevpool members. The "- 2*sizeof(block *)" gibberish is |
| compensating for that a pool_header's nextpool and prevpool members |
| immediately follow a pool_header's first two members: |
| |
| union { block *_padding; |
| uint count; } ref; |
| block *freeblock; |
| |
| each of which consume sizeof(block *) bytes. So what usedpools[i+i] really |
| contains is a fudged-up pointer p such that *if* C believes it's a poolp |
| pointer, then p->nextpool and p->prevpool are both p (meaning that the headed |
| circular list is empty). |
| |
| It's unclear why the usedpools setup is so convoluted. It could be to |
| minimize the amount of cache required to hold this heavily-referenced table |
| (which only *needs* the two interpool pointer members of a pool_header). OTOH, |
| referencing code has to remember to "double the index" and doing so isn't |
| free, usedpools[0] isn't a strictly legal pointer, and we're crucially relying |
| on that C doesn't insert any padding anywhere in a pool_header at or before |
| the prevpool member. |
| **************************************************************************** */ |
| |
| #define PTA(x) ((poolp )((uint8_t *)&(usedpools[2*(x)]) - 2*sizeof(block *))) |
| #define PT(x) PTA(x), PTA(x) |
| |
| static poolp usedpools[2 * ((NB_SMALL_SIZE_CLASSES + 7) / 8) * 8] = { |
| PT(0), PT(1), PT(2), PT(3), PT(4), PT(5), PT(6), PT(7) |
| #if NB_SMALL_SIZE_CLASSES > 8 |
| , PT(8), PT(9), PT(10), PT(11), PT(12), PT(13), PT(14), PT(15) |
| #if NB_SMALL_SIZE_CLASSES > 16 |
| , PT(16), PT(17), PT(18), PT(19), PT(20), PT(21), PT(22), PT(23) |
| #if NB_SMALL_SIZE_CLASSES > 24 |
| , PT(24), PT(25), PT(26), PT(27), PT(28), PT(29), PT(30), PT(31) |
| #if NB_SMALL_SIZE_CLASSES > 32 |
| , PT(32), PT(33), PT(34), PT(35), PT(36), PT(37), PT(38), PT(39) |
| #if NB_SMALL_SIZE_CLASSES > 40 |
| , PT(40), PT(41), PT(42), PT(43), PT(44), PT(45), PT(46), PT(47) |
| #if NB_SMALL_SIZE_CLASSES > 48 |
| , PT(48), PT(49), PT(50), PT(51), PT(52), PT(53), PT(54), PT(55) |
| #if NB_SMALL_SIZE_CLASSES > 56 |
| , PT(56), PT(57), PT(58), PT(59), PT(60), PT(61), PT(62), PT(63) |
| #if NB_SMALL_SIZE_CLASSES > 64 |
| #error "NB_SMALL_SIZE_CLASSES should be less than 64" |
| #endif /* NB_SMALL_SIZE_CLASSES > 64 */ |
| #endif /* NB_SMALL_SIZE_CLASSES > 56 */ |
| #endif /* NB_SMALL_SIZE_CLASSES > 48 */ |
| #endif /* NB_SMALL_SIZE_CLASSES > 40 */ |
| #endif /* NB_SMALL_SIZE_CLASSES > 32 */ |
| #endif /* NB_SMALL_SIZE_CLASSES > 24 */ |
| #endif /* NB_SMALL_SIZE_CLASSES > 16 */ |
| #endif /* NB_SMALL_SIZE_CLASSES > 8 */ |
| }; |
| |
| /*========================================================================== |
| Arena management. |
| |
| `arenas` is a vector of arena_objects. It contains maxarenas entries, some of |
| which may not be currently used (== they're arena_objects that aren't |
| currently associated with an allocated arena). Note that arenas proper are |
| separately malloc'ed. |
| |
| Prior to Python 2.5, arenas were never free()'ed. Starting with Python 2.5, |
| we do try to free() arenas, and use some mild heuristic strategies to increase |
| the likelihood that arenas eventually can be freed. |
| |
| unused_arena_objects |
| |
| This is a singly-linked list of the arena_objects that are currently not |
| being used (no arena is associated with them). Objects are taken off the |
| head of the list in new_arena(), and are pushed on the head of the list in |
| PyObject_Free() when the arena is empty. Key invariant: an arena_object |
| is on this list if and only if its .address member is 0. |
| |
| usable_arenas |
| |
| This is a doubly-linked list of the arena_objects associated with arenas |
| that have pools available. These pools are either waiting to be reused, |
| or have not been used before. The list is sorted to have the most- |
| allocated arenas first (ascending order based on the nfreepools member). |
| This means that the next allocation will come from a heavily used arena, |
| which gives the nearly empty arenas a chance to be returned to the system. |
| In my unscientific tests this dramatically improved the number of arenas |
| that could be freed. |
| |
| Note that an arena_object associated with an arena all of whose pools are |
| currently in use isn't on either list. |
| |
| Changed in Python 3.8: keeping usable_arenas sorted by number of free pools |
| used to be done by one-at-a-time linear search when an arena's number of |
| free pools changed. That could, overall, consume time quadratic in the |
| number of arenas. That didn't really matter when there were only a few |
| hundred arenas (typical!), but could be a timing disaster when there were |
| hundreds of thousands. See bpo-37029. |
| |
| Now we have a vector of "search fingers" to eliminate the need to search: |
| nfp2lasta[nfp] returns the last ("rightmost") arena in usable_arenas |
| with nfp free pools. This is NULL if and only if there is no arena with |
| nfp free pools in usable_arenas. |
| */ |
| |
| /* Array of objects used to track chunks of memory (arenas). */ |
| static struct arena_object* arenas = NULL; |
| /* Number of slots currently allocated in the `arenas` vector. */ |
| static uint maxarenas = 0; |
| |
| /* The head of the singly-linked, NULL-terminated list of available |
| * arena_objects. |
| */ |
| static struct arena_object* unused_arena_objects = NULL; |
| |
| /* The head of the doubly-linked, NULL-terminated at each end, list of |
| * arena_objects associated with arenas that have pools available. |
| */ |
| static struct arena_object* usable_arenas = NULL; |
| |
| /* nfp2lasta[nfp] is the last arena in usable_arenas with nfp free pools */ |
| static struct arena_object* nfp2lasta[MAX_POOLS_IN_ARENA + 1] = { NULL }; |
| |
| /* How many arena_objects do we initially allocate? |
| * 16 = can allocate 16 arenas = 16 * ARENA_SIZE = 4MB before growing the |
| * `arenas` vector. |
| */ |
| #define INITIAL_ARENA_OBJECTS 16 |
| |
| /* Number of arenas allocated that haven't been free()'d. */ |
| static size_t narenas_currently_allocated = 0; |
| |
| /* Total number of times malloc() called to allocate an arena. */ |
| static size_t ntimes_arena_allocated = 0; |
| /* High water mark (max value ever seen) for narenas_currently_allocated. */ |
| static size_t narenas_highwater = 0; |
| |
| static Py_ssize_t raw_allocated_blocks; |
| |
| Py_ssize_t |
| _Py_GetAllocatedBlocks(void) |
| { |
| 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 (arenas[i].address == 0) { |
| continue; |
| } |
| |
| uintptr_t base = (uintptr_t)_Py_ALIGN_UP(arenas[i].address, POOL_SIZE); |
| |
| /* visit every pool in the arena */ |
| assert(base <= (uintptr_t) arenas[i].pool_address); |
| for (; base < (uintptr_t) arenas[i].pool_address; base += POOL_SIZE) { |
| poolp p = (poolp)base; |
| n += p->ref.count; |
| } |
| } |
| return n; |
| } |
| |
| |
| /* 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(void) |
| { |
| struct arena_object* arenaobj; |
| uint excess; /* number of bytes above pool alignment */ |
| void *address; |
| static int debug_stats = -1; |
| |
| if (debug_stats == -1) { |
| const char *opt = Py_GETENV("PYTHONMALLOCSTATS"); |
| debug_stats = (opt != NULL && *opt != '\0'); |
| } |
| 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(*arenas)) |
| return NULL; /* overflow */ |
| #endif |
| nbytes = numarenas * sizeof(*arenas); |
| arenaobj = (struct arena_object *)PyMem_RawRealloc(arenas, nbytes); |
| if (arenaobj == NULL) |
| return NULL; |
| arenas = 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) { |
| arenas[i].address = 0; /* mark as unassociated */ |
| arenas[i].nextarena = i < numarenas - 1 ? |
| &arenas[i+1] : NULL; |
| } |
| |
| /* Update globals. */ |
| unused_arena_objects = &arenas[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 (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 = (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; |
| } |
| |
| |
| /* |
| 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(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 - arenas[arenaindex].address < ARENA_SIZE && |
| arenas[arenaindex].address != 0; |
| } |
| |
| |
| /*==========================================================================*/ |
| |
| // 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 = (block*)pool + pool->nextoffset; |
| pool->nextoffset += INDEX2SIZE(size); |
| *(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(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(); |
| 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 <= |
| (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((block*)pool <= (block*)usable_arenas->address + |
| ARENA_SIZE - POOL_SIZE); |
| pool->arenaindex = (uint)(usable_arenas - arenas); |
| assert(&arenas[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. */ |
| 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 = *(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 = (block *)pool + POOL_OVERHEAD; |
| pool->nextoffset = POOL_OVERHEAD + (size << 1); |
| pool->maxnextoffset = POOL_SIZE - size; |
| pool->freeblock = bp + size; |
| *(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(void *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]; |
| 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 = *(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(size); |
| } |
| |
| return (void *)bp; |
| } |
| |
| |
| static void * |
| _PyObject_Malloc(void *ctx, size_t nbytes) |
| { |
| void* ptr = pymalloc_alloc(ctx, nbytes); |
| if (LIKELY(ptr != NULL)) { |
| return ptr; |
| } |
| |
| ptr = PyMem_RawMalloc(nbytes); |
| if (ptr != NULL) { |
| raw_allocated_blocks++; |
| } |
| return ptr; |
| } |
| |
| |
| static 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; |
| |
| void* ptr = pymalloc_alloc(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(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(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 = &arenas[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; |
| |
| /* 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(void *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(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 */ |
| block *lastfree = pool->freeblock; |
| *(block **)p = lastfree; |
| pool->freeblock = (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(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(pool); |
| return 1; |
| } |
| |
| |
| static void |
| _PyObject_Free(void *ctx, void *p) |
| { |
| /* PyObject_Free(NULL) has no effect */ |
| if (p == NULL) { |
| return; |
| } |
| |
| if (UNLIKELY(!pymalloc_free(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(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(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; |
| } |
| |
| |
| static void * |
| _PyObject_Realloc(void *ctx, void *ptr, size_t nbytes) |
| { |
| void *ptr2; |
| |
| if (ptr == NULL) { |
| return _PyObject_Malloc(ctx, nbytes); |
| } |
| |
| if (pymalloc_realloc(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 |
| _Py_GetAllocatedBlocks(void) |
| { |
| return 0; |
| } |
| |
| #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; |
| } |
| } |
| |
| /* 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) { |
| memset(data, PYMEM_CLEANBYTE, nbytes); |
| } |
| |
| /* 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; |
| } |
| |
| static void * |
| _PyMem_DebugRawMalloc(void *ctx, size_t nbytes) |
| { |
| return _PyMem_DebugRawAlloc(0, ctx, nbytes); |
| } |
| |
| static 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. |
| */ |
| static 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; |
| memset(q, PYMEM_DEADBYTE, nbytes); |
| api->alloc.free(api->alloc.ctx, q); |
| } |
| |
| |
| static 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 |
| uint8_t save[2*ERASED_SIZE]; /* A copy of erased bytes. */ |
| |
| _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 |
| /* 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. |
| */ |
| 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); |
| } |
| |
| /* 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 |
| |
| /* 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)); |
| } |
| } |
| |
| 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"); |
| } |
| } |
| |
| static void * |
| _PyMem_DebugMalloc(void *ctx, size_t nbytes) |
| { |
| _PyMem_DebugCheckGIL(__func__); |
| return _PyMem_DebugRawMalloc(ctx, nbytes); |
| } |
| |
| static void * |
| _PyMem_DebugCalloc(void *ctx, size_t nelem, size_t elsize) |
| { |
| _PyMem_DebugCheckGIL(__func__); |
| return _PyMem_DebugRawCalloc(ctx, nelem, elsize); |
| } |
| |
| |
| static void |
| _PyMem_DebugFree(void *ctx, void *ptr) |
| { |
| _PyMem_DebugCheckGIL(__func__); |
| _PyMem_DebugRawFree(ctx, ptr); |
| } |
| |
| |
| static 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); |
| } |
| |
| |
| #ifdef WITH_PYMALLOC |
| |
| #ifdef Py_DEBUG |
| /* Is target in the list? The list is traversed via the nextpool pointers. |
| * The list may be NULL-terminated, or circular. Return 1 if target is in |
| * list, else 0. |
| */ |
| static int |
| pool_is_in_list(const poolp target, poolp list) |
| { |
| poolp origlist = list; |
| assert(target != NULL); |
| if (list == NULL) |
| return 0; |
| do { |
| if (target == list) |
| return 1; |
| list = list->nextpool; |
| } while (list != NULL && list != origlist); |
| return 0; |
| } |
| #endif |
| |
| /* Print summary info to "out" about the state of pymalloc's structures. |
| * In Py_DEBUG mode, also perform some expensive internal consistency |
| * checks. |
| * |
| * Return 0 if the memory debug hooks are not installed or no statistics was |
| * written into out, return 1 otherwise. |
| */ |
| int |
| _PyObject_DebugMallocStats(FILE *out) |
| { |
| if (!_PyMem_PymallocEnabled()) { |
| return 0; |
| } |
| |
| uint i; |
| const uint numclasses = SMALL_REQUEST_THRESHOLD >> ALIGNMENT_SHIFT; |
| /* # of pools, allocated blocks, and free blocks per class index */ |
| size_t numpools[SMALL_REQUEST_THRESHOLD >> ALIGNMENT_SHIFT]; |
| size_t numblocks[SMALL_REQUEST_THRESHOLD >> ALIGNMENT_SHIFT]; |
| size_t numfreeblocks[SMALL_REQUEST_THRESHOLD >> ALIGNMENT_SHIFT]; |
| /* total # of allocated bytes in used and full pools */ |
| size_t allocated_bytes = 0; |
| /* total # of available bytes in used pools */ |
| size_t available_bytes = 0; |
| /* # of free pools + pools not yet carved out of current arena */ |
| uint numfreepools = 0; |
| /* # of bytes for arena alignment padding */ |
| size_t arena_alignment = 0; |
| /* # of bytes in used and full pools used for pool_headers */ |
| size_t pool_header_bytes = 0; |
| /* # of bytes in used and full pools wasted due to quantization, |
| * i.e. the necessarily leftover space at the ends of used and |
| * full pools. |
| */ |
| size_t quantization = 0; |
| /* # of arenas actually allocated. */ |
| size_t narenas = 0; |
| /* running total -- should equal narenas * ARENA_SIZE */ |
| size_t total; |
| char buf[128]; |
| |
| fprintf(out, "Small block threshold = %d, in %u size classes.\n", |
| SMALL_REQUEST_THRESHOLD, numclasses); |
| |
| for (i = 0; i < numclasses; ++i) |
| numpools[i] = numblocks[i] = numfreeblocks[i] = 0; |
| |
| /* Because full pools aren't linked to from anything, it's easiest |
| * to march over all the arenas. If we're lucky, most of the memory |
| * will be living in full pools -- would be a shame to miss them. |
| */ |
| for (i = 0; i < maxarenas; ++i) { |
| uint j; |
| uintptr_t base = arenas[i].address; |
| |
| /* Skip arenas which are not allocated. */ |
| if (arenas[i].address == (uintptr_t)NULL) |
| continue; |
| narenas += 1; |
| |
| numfreepools += arenas[i].nfreepools; |
| |
| /* round up to pool alignment */ |
| if (base & (uintptr_t)POOL_SIZE_MASK) { |
| arena_alignment += POOL_SIZE; |
| base &= ~(uintptr_t)POOL_SIZE_MASK; |
| base += POOL_SIZE; |
| } |
| |
| /* visit every pool in the arena */ |
| assert(base <= (uintptr_t) arenas[i].pool_address); |
| for (j = 0; base < (uintptr_t) arenas[i].pool_address; |
| ++j, 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, arenas[i].freepools)); |
| #endif |
| continue; |
| } |
| ++numpools[sz]; |
| numblocks[sz] += p->ref.count; |
| freeblocks = NUMBLOCKS(sz) - p->ref.count; |
| numfreeblocks[sz] += freeblocks; |
| #ifdef Py_DEBUG |
| if (freeblocks > 0) |
| assert(pool_is_in_list(p, usedpools[sz + sz])); |
| #endif |
| } |
| } |
| assert(narenas == narenas_currently_allocated); |
| |
| fputc('\n', out); |
| fputs("class size num pools blocks in use avail blocks\n" |
| "----- ---- --------- ------------- ------------\n", |
| out); |
| |
| for (i = 0; i < numclasses; ++i) { |
| size_t p = numpools[i]; |
| size_t b = numblocks[i]; |
| size_t f = numfreeblocks[i]; |
| uint size = INDEX2SIZE(i); |
| if (p == 0) { |
| assert(b == 0 && f == 0); |
| continue; |
| } |
| fprintf(out, "%5u %6u %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); |
| |
| total = printone(out, "# bytes in allocated blocks", allocated_bytes); |
| total += printone(out, "# bytes in available blocks", available_bytes); |
| |
| PyOS_snprintf(buf, sizeof(buf), |
| "%u unused pools * %d bytes", numfreepools, POOL_SIZE); |
| total += printone(out, buf, (size_t)numfreepools * POOL_SIZE); |
| |
| total += printone(out, "# bytes lost to pool headers", pool_header_bytes); |
| total += printone(out, "# bytes lost to quantization", quantization); |
| total += printone(out, "# bytes lost to arena alignment", arena_alignment); |
| (void)printone(out, "Total", total); |
| return 1; |
| } |
| |
| #endif /* #ifdef WITH_PYMALLOC */ |