Tim Peters | 8b078f9 | 2002-04-28 04:11:46 +0000 | [diff] [blame] | 1 | /* The PyObject_ memory family: high-level object memory interfaces. |
| 2 | See pymem.h for the low-level PyMem_ family. |
| 3 | */ |
Guido van Rossum | f70e43a | 1991-02-19 12:39:46 +0000 | [diff] [blame] | 4 | |
Fred Drake | 3cf4d2b | 2000-07-09 00:55:06 +0000 | [diff] [blame] | 5 | #ifndef Py_OBJIMPL_H |
| 6 | #define Py_OBJIMPL_H |
Peter Schneider-Kamp | 25f6894 | 2000-07-31 22:19:30 +0000 | [diff] [blame] | 7 | |
| 8 | #include "pymem.h" |
| 9 | |
Fred Drake | 3cf4d2b | 2000-07-09 00:55:06 +0000 | [diff] [blame] | 10 | #ifdef __cplusplus |
| 11 | extern "C" { |
| 12 | #endif |
| 13 | |
Tim Peters | 8b078f9 | 2002-04-28 04:11:46 +0000 | [diff] [blame] | 14 | /* BEWARE: |
| 15 | |
| 16 | Each interface exports both functions and macros. Extension modules should |
| 17 | use the functions, to ensure binary compatibility across Python versions. |
| 18 | Because the Python implementation is free to change internal details, and |
| 19 | the macros may (or may not) expose details for speed, if you do use the |
| 20 | macros you must recompile your extensions with each Python release. |
| 21 | |
| 22 | Never mix calls to PyObject_ memory functions with calls to the platform |
| 23 | malloc/realloc/ calloc/free, or with calls to PyMem_. |
| 24 | */ |
| 25 | |
Guido van Rossum | 85a5fbb | 1990-10-14 12:07:46 +0000 | [diff] [blame] | 26 | /* |
Guido van Rossum | b18618d | 2000-05-03 23:44:39 +0000 | [diff] [blame] | 27 | Functions and macros for modules that implement new object types. |
Guido van Rossum | 85a5fbb | 1990-10-14 12:07:46 +0000 | [diff] [blame] | 28 | |
Tim Peters | 8b078f9 | 2002-04-28 04:11:46 +0000 | [diff] [blame] | 29 | - PyObject_New(type, typeobj) allocates memory for a new object of the given |
| 30 | type, and initializes part of it. 'type' must be the C structure type used |
| 31 | to represent the object, and 'typeobj' the address of the corresponding |
| 32 | type object. Reference count and type pointer are filled in; the rest of |
| 33 | the bytes of the object are *undefined*! The resulting expression type is |
| 34 | 'type *'. The size of the object is determined by the tp_basicsize field |
| 35 | of the type object. |
Guido van Rossum | 85a5fbb | 1990-10-14 12:07:46 +0000 | [diff] [blame] | 36 | |
Tim Peters | 8b078f9 | 2002-04-28 04:11:46 +0000 | [diff] [blame] | 37 | - PyObject_NewVar(type, typeobj, n) is similar but allocates a variable-size |
| 38 | object with room for n items. In addition to the refcount and type pointer |
| 39 | fields, this also fills in the ob_size field. |
Guido van Rossum | 85a5fbb | 1990-10-14 12:07:46 +0000 | [diff] [blame] | 40 | |
Tim Peters | 8b078f9 | 2002-04-28 04:11:46 +0000 | [diff] [blame] | 41 | - PyObject_Del(op) releases the memory allocated for an object. It does not |
| 42 | run a destructor -- it only frees the memory. PyObject_Free is identical. |
Guido van Rossum | b18618d | 2000-05-03 23:44:39 +0000 | [diff] [blame] | 43 | |
Tim Peters | 8b078f9 | 2002-04-28 04:11:46 +0000 | [diff] [blame] | 44 | - PyObject_Init(op, typeobj) and PyObject_InitVar(op, typeobj, n) don't |
| 45 | allocate memory. Instead of a 'type' parameter, they take a pointer to a |
| 46 | new object (allocated by an arbitrary allocator), and initialize its object |
| 47 | header fields. |
Guido van Rossum | b18618d | 2000-05-03 23:44:39 +0000 | [diff] [blame] | 48 | |
Tim Peters | 8b078f9 | 2002-04-28 04:11:46 +0000 | [diff] [blame] | 49 | Note that objects created with PyObject_{New, NewVar} are allocated using the |
| 50 | specialized Python allocator (implemented in obmalloc.c), if WITH_PYMALLOC is |
| 51 | enabled. In addition, a special debugging allocator is used if PYMALLOC_DEBUG |
| 52 | is also #defined. |
Guido van Rossum | b18618d | 2000-05-03 23:44:39 +0000 | [diff] [blame] | 53 | |
Tim Peters | 8b078f9 | 2002-04-28 04:11:46 +0000 | [diff] [blame] | 54 | In case a specific form of memory management is needed (for example, if you |
| 55 | must use the platform malloc heap(s), or shared memory, or C++ local storage or |
| 56 | operator new), you must first allocate the object with your custom allocator, |
| 57 | then pass its pointer to PyObject_{Init, InitVar} for filling in its Python- |
| 58 | specific fields: reference count, type pointer, possibly others. You should |
| 59 | be aware that Python no control over these objects because they don't |
| 60 | cooperate with the Python memory manager. Such objects may not be eligible |
| 61 | for automatic garbage collection and you have to make sure that they are |
| 62 | released accordingly whenever their destructor gets called (cf. the specific |
Guido van Rossum | b18618d | 2000-05-03 23:44:39 +0000 | [diff] [blame] | 63 | form of memory management you're using). |
| 64 | |
Tim Peters | 8b078f9 | 2002-04-28 04:11:46 +0000 | [diff] [blame] | 65 | Unless you have specific memory management requirements, use |
| 66 | PyObject_{New, NewVar, Del}. |
| 67 | */ |
Guido van Rossum | b18618d | 2000-05-03 23:44:39 +0000 | [diff] [blame] | 68 | |
Tim Peters | 6d483d3 | 2001-10-06 21:27:34 +0000 | [diff] [blame] | 69 | /* |
Guido van Rossum | b18618d | 2000-05-03 23:44:39 +0000 | [diff] [blame] | 70 | * Raw object memory interface |
| 71 | * =========================== |
| 72 | */ |
| 73 | |
Tim Peters | e9e7452 | 2002-04-12 05:21:34 +0000 | [diff] [blame] | 74 | /* Functions to call the same malloc/realloc/free as used by Python's |
| 75 | object allocator. If WITH_PYMALLOC is enabled, these may differ from |
| 76 | the platform malloc/realloc/free. The Python object allocator is |
| 77 | designed for fast, cache-conscious allocation of many "small" objects, |
Tim Peters | 8b078f9 | 2002-04-28 04:11:46 +0000 | [diff] [blame] | 78 | and with low hidden memory overhead. |
| 79 | |
| 80 | PyObject_Malloc(0) returns a unique non-NULL pointer if possible. |
| 81 | |
| 82 | PyObject_Realloc(NULL, n) acts like PyObject_Malloc(n). |
| 83 | PyObject_Realloc(p != NULL, 0) does not return NULL, or free the memory |
| 84 | at p. |
| 85 | |
| 86 | Returned pointers must be checked for NULL explicitly; no action is |
| 87 | performed on failure other than to return NULL (no warning it printed, no |
| 88 | exception is set, etc). |
| 89 | |
| 90 | For allocating objects, use PyObject_{New, NewVar} instead whenever |
| 91 | possible. The PyObject_{Malloc, Realloc, Free} family is exposed |
| 92 | so that you can exploit Python's small-block allocator for non-object |
| 93 | uses. If you must use these routines to allocate object memory, make sure |
| 94 | the object gets initialized via PyObject_{Init, InitVar} after obtaining |
| 95 | the raw memory. |
| 96 | */ |
Victor Stinner | 0507bf5 | 2013-07-07 02:05:46 +0200 | [diff] [blame] | 97 | PyAPI_FUNC(void *) PyObject_Malloc(size_t size); |
| 98 | PyAPI_FUNC(void *) PyObject_Realloc(void *ptr, size_t new_size); |
| 99 | PyAPI_FUNC(void) PyObject_Free(void *ptr); |
Guido van Rossum | b18618d | 2000-05-03 23:44:39 +0000 | [diff] [blame] | 100 | |
Antoine Pitrou | f9d0b12 | 2012-12-09 14:28:26 +0100 | [diff] [blame] | 101 | /* This function returns the number of allocated memory blocks, regardless of size */ |
| 102 | PyAPI_FUNC(Py_ssize_t) _Py_GetAllocatedBlocks(void); |
Neil Schemenauer | 3e7b893 | 2002-04-12 02:38:45 +0000 | [diff] [blame] | 103 | |
Guido van Rossum | b18618d | 2000-05-03 23:44:39 +0000 | [diff] [blame] | 104 | /* Macros */ |
Neil Schemenauer | 3e7b893 | 2002-04-12 02:38:45 +0000 | [diff] [blame] | 105 | #ifdef WITH_PYMALLOC |
David Malcolm | 49526f4 | 2012-06-22 14:55:41 -0400 | [diff] [blame] | 106 | #ifndef Py_LIMITED_API |
| 107 | PyAPI_FUNC(void) _PyObject_DebugMallocStats(FILE *out); |
| 108 | #endif /* #ifndef Py_LIMITED_API */ |
Victor Stinner | 0507bf5 | 2013-07-07 02:05:46 +0200 | [diff] [blame] | 109 | #endif |
Neil Schemenauer | 3e7b893 | 2002-04-12 02:38:45 +0000 | [diff] [blame] | 110 | |
Victor Stinner | 0507bf5 | 2013-07-07 02:05:46 +0200 | [diff] [blame] | 111 | /* Macros */ |
Antoine Pitrou | f95a1b3 | 2010-05-09 15:52:27 +0000 | [diff] [blame] | 112 | #define PyObject_MALLOC PyObject_Malloc |
| 113 | #define PyObject_REALLOC PyObject_Realloc |
| 114 | #define PyObject_FREE PyObject_Free |
Antoine Pitrou | f95a1b3 | 2010-05-09 15:52:27 +0000 | [diff] [blame] | 115 | #define PyObject_Del PyObject_Free |
Victor Stinner | 0507bf5 | 2013-07-07 02:05:46 +0200 | [diff] [blame] | 116 | #define PyObject_DEL PyObject_Free |
| 117 | |
Neil Schemenauer | 3e7b893 | 2002-04-12 02:38:45 +0000 | [diff] [blame] | 118 | |
Guido van Rossum | b18618d | 2000-05-03 23:44:39 +0000 | [diff] [blame] | 119 | /* |
| 120 | * Generic object allocator interface |
| 121 | * ================================== |
| 122 | */ |
| 123 | |
| 124 | /* Functions */ |
Mark Hammond | 91a681d | 2002-08-12 07:21:58 +0000 | [diff] [blame] | 125 | PyAPI_FUNC(PyObject *) PyObject_Init(PyObject *, PyTypeObject *); |
| 126 | PyAPI_FUNC(PyVarObject *) PyObject_InitVar(PyVarObject *, |
Martin v. Löwis | 18e1655 | 2006-02-15 17:27:45 +0000 | [diff] [blame] | 127 | PyTypeObject *, Py_ssize_t); |
Mark Hammond | 91a681d | 2002-08-12 07:21:58 +0000 | [diff] [blame] | 128 | PyAPI_FUNC(PyObject *) _PyObject_New(PyTypeObject *); |
Martin v. Löwis | 18e1655 | 2006-02-15 17:27:45 +0000 | [diff] [blame] | 129 | PyAPI_FUNC(PyVarObject *) _PyObject_NewVar(PyTypeObject *, Py_ssize_t); |
Guido van Rossum | 85a5fbb | 1990-10-14 12:07:46 +0000 | [diff] [blame] | 130 | |
Guido van Rossum | b18618d | 2000-05-03 23:44:39 +0000 | [diff] [blame] | 131 | #define PyObject_New(type, typeobj) \ |
Antoine Pitrou | f95a1b3 | 2010-05-09 15:52:27 +0000 | [diff] [blame] | 132 | ( (type *) _PyObject_New(typeobj) ) |
Guido van Rossum | b18618d | 2000-05-03 23:44:39 +0000 | [diff] [blame] | 133 | #define PyObject_NewVar(type, typeobj, n) \ |
Antoine Pitrou | f95a1b3 | 2010-05-09 15:52:27 +0000 | [diff] [blame] | 134 | ( (type *) _PyObject_NewVar((typeobj), (n)) ) |
Guido van Rossum | a330996 | 1993-07-28 09:05:47 +0000 | [diff] [blame] | 135 | |
Andrew M. Kuchling | 1582a3a | 2000-08-16 12:27:23 +0000 | [diff] [blame] | 136 | /* Macros trading binary compatibility for speed. See also pymem.h. |
Guido van Rossum | b18618d | 2000-05-03 23:44:39 +0000 | [diff] [blame] | 137 | Note that these macros expect non-NULL object pointers.*/ |
| 138 | #define PyObject_INIT(op, typeobj) \ |
Antoine Pitrou | f95a1b3 | 2010-05-09 15:52:27 +0000 | [diff] [blame] | 139 | ( Py_TYPE(op) = (typeobj), _Py_NewReference((PyObject *)(op)), (op) ) |
Guido van Rossum | b18618d | 2000-05-03 23:44:39 +0000 | [diff] [blame] | 140 | #define PyObject_INIT_VAR(op, typeobj, size) \ |
Antoine Pitrou | f95a1b3 | 2010-05-09 15:52:27 +0000 | [diff] [blame] | 141 | ( Py_SIZE(op) = (size), PyObject_INIT((op), (typeobj)) ) |
Guido van Rossum | 5a84914 | 1996-07-21 02:23:54 +0000 | [diff] [blame] | 142 | |
Guido van Rossum | b18618d | 2000-05-03 23:44:39 +0000 | [diff] [blame] | 143 | #define _PyObject_SIZE(typeobj) ( (typeobj)->tp_basicsize ) |
Tim Peters | 6d483d3 | 2001-10-06 21:27:34 +0000 | [diff] [blame] | 144 | |
Tim Peters | f2a67da | 2001-10-07 03:54:51 +0000 | [diff] [blame] | 145 | /* _PyObject_VAR_SIZE returns the number of bytes (as size_t) allocated for a |
| 146 | vrbl-size object with nitems items, exclusive of gc overhead (if any). The |
| 147 | value is rounded up to the closest multiple of sizeof(void *), in order to |
| 148 | ensure that pointer fields at the end of the object are correctly aligned |
| 149 | for the platform (this is of special importance for subclasses of, e.g., |
Serhiy Storchaka | 9594942 | 2013-08-27 19:40:23 +0300 | [diff] [blame] | 150 | str or int, so that pointers can be stored after the embedded data). |
Tim Peters | 6d483d3 | 2001-10-06 21:27:34 +0000 | [diff] [blame] | 151 | |
Tim Peters | f2a67da | 2001-10-07 03:54:51 +0000 | [diff] [blame] | 152 | Note that there's no memory wastage in doing this, as malloc has to |
| 153 | return (at worst) pointer-aligned memory anyway. |
Tim Peters | 6d483d3 | 2001-10-06 21:27:34 +0000 | [diff] [blame] | 154 | */ |
Tim Peters | f2a67da | 2001-10-07 03:54:51 +0000 | [diff] [blame] | 155 | #if ((SIZEOF_VOID_P - 1) & SIZEOF_VOID_P) != 0 |
| 156 | # error "_PyObject_VAR_SIZE requires SIZEOF_VOID_P be a power of 2" |
| 157 | #endif |
| 158 | |
Antoine Pitrou | f95a1b3 | 2010-05-09 15:52:27 +0000 | [diff] [blame] | 159 | #define _PyObject_VAR_SIZE(typeobj, nitems) \ |
Antoine Pitrou | ca8aa4a | 2012-09-20 20:56:47 +0200 | [diff] [blame] | 160 | _Py_SIZE_ROUND_UP((typeobj)->tp_basicsize + \ |
| 161 | (nitems)*(typeobj)->tp_itemsize, \ |
| 162 | SIZEOF_VOID_P) |
Guido van Rossum | 5a84914 | 1996-07-21 02:23:54 +0000 | [diff] [blame] | 163 | |
Guido van Rossum | b18618d | 2000-05-03 23:44:39 +0000 | [diff] [blame] | 164 | #define PyObject_NEW(type, typeobj) \ |
| 165 | ( (type *) PyObject_Init( \ |
Antoine Pitrou | f95a1b3 | 2010-05-09 15:52:27 +0000 | [diff] [blame] | 166 | (PyObject *) PyObject_MALLOC( _PyObject_SIZE(typeobj) ), (typeobj)) ) |
Tim Peters | 6d483d3 | 2001-10-06 21:27:34 +0000 | [diff] [blame] | 167 | |
Tim Peters | f2a67da | 2001-10-07 03:54:51 +0000 | [diff] [blame] | 168 | #define PyObject_NEW_VAR(type, typeobj, n) \ |
| 169 | ( (type *) PyObject_InitVar( \ |
| 170 | (PyVarObject *) PyObject_MALLOC(_PyObject_VAR_SIZE((typeobj),(n)) ),\ |
| 171 | (typeobj), (n)) ) |
Guido van Rossum | b18618d | 2000-05-03 23:44:39 +0000 | [diff] [blame] | 172 | |
| 173 | /* This example code implements an object constructor with a custom |
| 174 | allocator, where PyObject_New is inlined, and shows the important |
| 175 | distinction between two steps (at least): |
| 176 | 1) the actual allocation of the object storage; |
| 177 | 2) the initialization of the Python specific fields |
Antoine Pitrou | f95a1b3 | 2010-05-09 15:52:27 +0000 | [diff] [blame] | 178 | in this storage with PyObject_{Init, InitVar}. |
Guido van Rossum | b18618d | 2000-05-03 23:44:39 +0000 | [diff] [blame] | 179 | |
| 180 | PyObject * |
| 181 | YourObject_New(...) |
| 182 | { |
| 183 | PyObject *op; |
| 184 | |
| 185 | op = (PyObject *) Your_Allocator(_PyObject_SIZE(YourTypeStruct)); |
| 186 | if (op == NULL) |
Antoine Pitrou | f95a1b3 | 2010-05-09 15:52:27 +0000 | [diff] [blame] | 187 | return PyErr_NoMemory(); |
Guido van Rossum | b18618d | 2000-05-03 23:44:39 +0000 | [diff] [blame] | 188 | |
Tim Peters | 8b078f9 | 2002-04-28 04:11:46 +0000 | [diff] [blame] | 189 | PyObject_Init(op, &YourTypeStruct); |
Guido van Rossum | b18618d | 2000-05-03 23:44:39 +0000 | [diff] [blame] | 190 | |
| 191 | op->ob_field = value; |
| 192 | ... |
| 193 | return op; |
| 194 | } |
| 195 | |
| 196 | Note that in C++, the use of the new operator usually implies that |
| 197 | the 1st step is performed automatically for you, so in a C++ class |
Tim Peters | 8b078f9 | 2002-04-28 04:11:46 +0000 | [diff] [blame] | 198 | constructor you would start directly with PyObject_Init/InitVar |
| 199 | */ |
Guido van Rossum | 5a84914 | 1996-07-21 02:23:54 +0000 | [diff] [blame] | 200 | |
Victor Stinner | 0507bf5 | 2013-07-07 02:05:46 +0200 | [diff] [blame] | 201 | #ifndef Py_LIMITED_API |
| 202 | typedef struct { |
| 203 | /* user context passed as the first argument to the 2 functions */ |
| 204 | void *ctx; |
| 205 | |
| 206 | /* allocate an arena of size bytes */ |
| 207 | void* (*alloc) (void *ctx, size_t size); |
| 208 | |
| 209 | /* free an arena */ |
| 210 | void (*free) (void *ctx, void *ptr, size_t size); |
| 211 | } PyObjectArenaAllocator; |
| 212 | |
| 213 | /* Get the arena allocator. */ |
| 214 | PyAPI_FUNC(void) PyObject_GetArenaAllocator(PyObjectArenaAllocator *allocator); |
| 215 | |
| 216 | /* Set the arena allocator. */ |
| 217 | PyAPI_FUNC(void) PyObject_SetArenaAllocator(PyObjectArenaAllocator *allocator); |
| 218 | #endif |
| 219 | |
| 220 | |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 221 | /* |
| 222 | * Garbage Collection Support |
| 223 | * ========================== |
| 224 | */ |
Jeremy Hylton | d08b4c4 | 2000-06-23 19:37:02 +0000 | [diff] [blame] | 225 | |
Guido van Rossum | e13ddc9 | 2003-04-17 17:29:22 +0000 | [diff] [blame] | 226 | /* C equivalent of gc.collect(). */ |
Neal Norwitz | 7b216c5 | 2006-03-04 20:01:53 +0000 | [diff] [blame] | 227 | PyAPI_FUNC(Py_ssize_t) PyGC_Collect(void); |
Guido van Rossum | e13ddc9 | 2003-04-17 17:29:22 +0000 | [diff] [blame] | 228 | |
Antoine Pitrou | fef34e3 | 2013-05-19 01:11:58 +0200 | [diff] [blame] | 229 | #ifndef Py_LIMITED_API |
| 230 | PyAPI_FUNC(Py_ssize_t) _PyGC_CollectNoFail(void); |
| 231 | #endif |
| 232 | |
Neil Schemenauer | 74b5ade | 2001-08-29 23:49:28 +0000 | [diff] [blame] | 233 | /* Test if a type has a GC head */ |
| 234 | #define PyType_IS_GC(t) PyType_HasFeature((t), Py_TPFLAGS_HAVE_GC) |
Jeremy Hylton | d08b4c4 | 2000-06-23 19:37:02 +0000 | [diff] [blame] | 235 | |
Neil Schemenauer | 74b5ade | 2001-08-29 23:49:28 +0000 | [diff] [blame] | 236 | /* Test if an object has a GC head */ |
Christian Heimes | 90aa764 | 2007-12-19 02:45:37 +0000 | [diff] [blame] | 237 | #define PyObject_IS_GC(o) (PyType_IS_GC(Py_TYPE(o)) && \ |
Antoine Pitrou | f95a1b3 | 2010-05-09 15:52:27 +0000 | [diff] [blame] | 238 | (Py_TYPE(o)->tp_is_gc == NULL || Py_TYPE(o)->tp_is_gc(o))) |
Jeremy Hylton | c5007aa | 2000-06-30 05:02:53 +0000 | [diff] [blame] | 239 | |
Martin v. Löwis | 4129068 | 2006-02-16 14:56:14 +0000 | [diff] [blame] | 240 | PyAPI_FUNC(PyVarObject *) _PyObject_GC_Resize(PyVarObject *, Py_ssize_t); |
Neil Schemenauer | 74b5ade | 2001-08-29 23:49:28 +0000 | [diff] [blame] | 241 | #define PyObject_GC_Resize(type, op, n) \ |
Antoine Pitrou | f95a1b3 | 2010-05-09 15:52:27 +0000 | [diff] [blame] | 242 | ( (type *) _PyObject_GC_Resize((PyVarObject *)(op), (n)) ) |
Neil Schemenauer | 74b5ade | 2001-08-29 23:49:28 +0000 | [diff] [blame] | 243 | |
Tim Peters | 8b078f9 | 2002-04-28 04:11:46 +0000 | [diff] [blame] | 244 | /* GC information is stored BEFORE the object structure. */ |
Martin v. Löwis | 4d0d471 | 2010-12-03 20:14:31 +0000 | [diff] [blame] | 245 | #ifndef Py_LIMITED_API |
Tim Peters | 9e4ca10 | 2001-10-11 18:31:31 +0000 | [diff] [blame] | 246 | typedef union _gc_head { |
Antoine Pitrou | f95a1b3 | 2010-05-09 15:52:27 +0000 | [diff] [blame] | 247 | struct { |
| 248 | union _gc_head *gc_next; |
| 249 | union _gc_head *gc_prev; |
| 250 | Py_ssize_t gc_refs; |
| 251 | } gc; |
Gregory P. Smith | e348c8d | 2012-12-10 18:05:05 -0800 | [diff] [blame] | 252 | double dummy; /* force worst-case alignment */ |
Neil Schemenauer | 74b5ade | 2001-08-29 23:49:28 +0000 | [diff] [blame] | 253 | } PyGC_Head; |
| 254 | |
Neil Schemenauer | b1094f0 | 2002-05-04 05:36:06 +0000 | [diff] [blame] | 255 | extern PyGC_Head *_PyGC_generation0; |
Neil Schemenauer | 74b5ade | 2001-08-29 23:49:28 +0000 | [diff] [blame] | 256 | |
Neil Schemenauer | ef99723 | 2002-03-28 21:06:16 +0000 | [diff] [blame] | 257 | #define _Py_AS_GC(o) ((PyGC_Head *)(o)-1) |
| 258 | |
Antoine Pitrou | 796564c | 2013-07-30 19:59:21 +0200 | [diff] [blame] | 259 | /* Bit 0 is set when tp_finalize is called */ |
| 260 | #define _PyGC_REFS_MASK_FINALIZED (1 << 0) |
| 261 | /* The (N-1) most significant bits contain the gc state / refcount */ |
| 262 | #define _PyGC_REFS_SHIFT (1) |
| 263 | #define _PyGC_REFS_MASK (((size_t) -1) << _PyGC_REFS_SHIFT) |
| 264 | |
| 265 | #define _PyGCHead_REFS(g) ((g)->gc.gc_refs >> _PyGC_REFS_SHIFT) |
| 266 | #define _PyGCHead_SET_REFS(g, v) do { \ |
| 267 | (g)->gc.gc_refs = ((g)->gc.gc_refs & ~_PyGC_REFS_MASK) \ |
| 268 | | (v << _PyGC_REFS_SHIFT); \ |
| 269 | } while (0) |
| 270 | #define _PyGCHead_DECREF(g) ((g)->gc.gc_refs -= 1 << _PyGC_REFS_SHIFT) |
| 271 | |
| 272 | #define _PyGCHead_FINALIZED(g) (((g)->gc.gc_refs & _PyGC_REFS_MASK_FINALIZED) != 0) |
| 273 | #define _PyGCHead_SET_FINALIZED(g, v) do { \ |
| 274 | (g)->gc.gc_refs = ((g)->gc.gc_refs & ~_PyGC_REFS_MASK_FINALIZED) \ |
| 275 | | (v != 0); \ |
| 276 | } while (0) |
| 277 | |
| 278 | #define _PyGC_FINALIZED(o) _PyGCHead_FINALIZED(_Py_AS_GC(o)) |
| 279 | #define _PyGC_SET_FINALIZED(o, v) _PyGCHead_SET_FINALIZED(_Py_AS_GC(o), v) |
| 280 | |
| 281 | #define _PyGC_REFS(o) _PyGCHead_REFS(_Py_AS_GC(o)) |
| 282 | |
Antoine Pitrou | f95a1b3 | 2010-05-09 15:52:27 +0000 | [diff] [blame] | 283 | #define _PyGC_REFS_UNTRACKED (-2) |
| 284 | #define _PyGC_REFS_REACHABLE (-3) |
| 285 | #define _PyGC_REFS_TENTATIVELY_UNREACHABLE (-4) |
Tim Peters | ea40563 | 2002-07-02 00:52:30 +0000 | [diff] [blame] | 286 | |
Neil Schemenauer | 74b5ade | 2001-08-29 23:49:28 +0000 | [diff] [blame] | 287 | /* Tell the GC to track this object. NB: While the object is tracked the |
| 288 | * collector it must be safe to call the ob_traverse method. */ |
| 289 | #define _PyObject_GC_TRACK(o) do { \ |
Antoine Pitrou | f95a1b3 | 2010-05-09 15:52:27 +0000 | [diff] [blame] | 290 | PyGC_Head *g = _Py_AS_GC(o); \ |
Antoine Pitrou | 796564c | 2013-07-30 19:59:21 +0200 | [diff] [blame] | 291 | if (_PyGCHead_REFS(g) != _PyGC_REFS_UNTRACKED) \ |
Antoine Pitrou | f95a1b3 | 2010-05-09 15:52:27 +0000 | [diff] [blame] | 292 | Py_FatalError("GC object already tracked"); \ |
Antoine Pitrou | 796564c | 2013-07-30 19:59:21 +0200 | [diff] [blame] | 293 | _PyGCHead_SET_REFS(g, _PyGC_REFS_REACHABLE); \ |
Antoine Pitrou | f95a1b3 | 2010-05-09 15:52:27 +0000 | [diff] [blame] | 294 | g->gc.gc_next = _PyGC_generation0; \ |
| 295 | g->gc.gc_prev = _PyGC_generation0->gc.gc_prev; \ |
| 296 | g->gc.gc_prev->gc.gc_next = g; \ |
| 297 | _PyGC_generation0->gc.gc_prev = g; \ |
Neil Schemenauer | 74b5ade | 2001-08-29 23:49:28 +0000 | [diff] [blame] | 298 | } while (0); |
| 299 | |
Tim Peters | 6fc13d9 | 2002-07-02 18:12:35 +0000 | [diff] [blame] | 300 | /* Tell the GC to stop tracking this object. |
| 301 | * gc_next doesn't need to be set to NULL, but doing so is a good |
| 302 | * way to provoke memory errors if calling code is confused. |
| 303 | */ |
Neil Schemenauer | 74b5ade | 2001-08-29 23:49:28 +0000 | [diff] [blame] | 304 | #define _PyObject_GC_UNTRACK(o) do { \ |
Antoine Pitrou | f95a1b3 | 2010-05-09 15:52:27 +0000 | [diff] [blame] | 305 | PyGC_Head *g = _Py_AS_GC(o); \ |
Antoine Pitrou | 796564c | 2013-07-30 19:59:21 +0200 | [diff] [blame] | 306 | assert(_PyGCHead_REFS(g) != _PyGC_REFS_UNTRACKED); \ |
| 307 | _PyGCHead_SET_REFS(g, _PyGC_REFS_UNTRACKED); \ |
Antoine Pitrou | f95a1b3 | 2010-05-09 15:52:27 +0000 | [diff] [blame] | 308 | g->gc.gc_prev->gc.gc_next = g->gc.gc_next; \ |
| 309 | g->gc.gc_next->gc.gc_prev = g->gc.gc_prev; \ |
| 310 | g->gc.gc_next = NULL; \ |
Neil Schemenauer | 74b5ade | 2001-08-29 23:49:28 +0000 | [diff] [blame] | 311 | } while (0); |
| 312 | |
Antoine Pitrou | 3a652b1 | 2009-03-23 18:52:06 +0000 | [diff] [blame] | 313 | /* True if the object is currently tracked by the GC. */ |
| 314 | #define _PyObject_GC_IS_TRACKED(o) \ |
Antoine Pitrou | 796564c | 2013-07-30 19:59:21 +0200 | [diff] [blame] | 315 | (_PyGC_REFS(o) != _PyGC_REFS_UNTRACKED) |
Antoine Pitrou | f95a1b3 | 2010-05-09 15:52:27 +0000 | [diff] [blame] | 316 | |
Antoine Pitrou | 3a652b1 | 2009-03-23 18:52:06 +0000 | [diff] [blame] | 317 | /* True if the object may be tracked by the GC in the future, or already is. |
| 318 | This can be useful to implement some optimizations. */ |
| 319 | #define _PyObject_GC_MAY_BE_TRACKED(obj) \ |
Antoine Pitrou | f95a1b3 | 2010-05-09 15:52:27 +0000 | [diff] [blame] | 320 | (PyObject_IS_GC(obj) && \ |
| 321 | (!PyTuple_CheckExact(obj) || _PyObject_GC_IS_TRACKED(obj))) |
Martin v. Löwis | 4d0d471 | 2010-12-03 20:14:31 +0000 | [diff] [blame] | 322 | #endif /* Py_LIMITED_API */ |
Antoine Pitrou | 3a652b1 | 2009-03-23 18:52:06 +0000 | [diff] [blame] | 323 | |
Mark Hammond | 91a681d | 2002-08-12 07:21:58 +0000 | [diff] [blame] | 324 | PyAPI_FUNC(PyObject *) _PyObject_GC_Malloc(size_t); |
| 325 | PyAPI_FUNC(PyObject *) _PyObject_GC_New(PyTypeObject *); |
Martin v. Löwis | 18e1655 | 2006-02-15 17:27:45 +0000 | [diff] [blame] | 326 | PyAPI_FUNC(PyVarObject *) _PyObject_GC_NewVar(PyTypeObject *, Py_ssize_t); |
Mark Hammond | 91a681d | 2002-08-12 07:21:58 +0000 | [diff] [blame] | 327 | PyAPI_FUNC(void) PyObject_GC_Track(void *); |
| 328 | PyAPI_FUNC(void) PyObject_GC_UnTrack(void *); |
| 329 | PyAPI_FUNC(void) PyObject_GC_Del(void *); |
Neil Schemenauer | 74b5ade | 2001-08-29 23:49:28 +0000 | [diff] [blame] | 330 | |
| 331 | #define PyObject_GC_New(type, typeobj) \ |
Antoine Pitrou | f95a1b3 | 2010-05-09 15:52:27 +0000 | [diff] [blame] | 332 | ( (type *) _PyObject_GC_New(typeobj) ) |
Neil Schemenauer | 74b5ade | 2001-08-29 23:49:28 +0000 | [diff] [blame] | 333 | #define PyObject_GC_NewVar(type, typeobj, n) \ |
Antoine Pitrou | f95a1b3 | 2010-05-09 15:52:27 +0000 | [diff] [blame] | 334 | ( (type *) _PyObject_GC_NewVar((typeobj), (n)) ) |
Neil Schemenauer | 3e7b893 | 2002-04-12 02:38:45 +0000 | [diff] [blame] | 335 | |
Neil Schemenauer | 74b5ade | 2001-08-29 23:49:28 +0000 | [diff] [blame] | 336 | |
Tim Peters | eda2930 | 2004-07-15 04:05:59 +0000 | [diff] [blame] | 337 | /* Utility macro to help write tp_traverse functions. |
| 338 | * To use this macro, the tp_traverse function must name its arguments |
| 339 | * "visit" and "arg". This is intended to keep tp_traverse functions |
| 340 | * looking as much alike as possible. |
| 341 | */ |
Antoine Pitrou | f95a1b3 | 2010-05-09 15:52:27 +0000 | [diff] [blame] | 342 | #define Py_VISIT(op) \ |
| 343 | do { \ |
| 344 | if (op) { \ |
| 345 | int vret = visit((PyObject *)(op), arg); \ |
| 346 | if (vret) \ |
| 347 | return vret; \ |
| 348 | } \ |
| 349 | } while (0) |
Jim Fulton | aa6389e | 2004-07-14 19:08:17 +0000 | [diff] [blame] | 350 | |
Jeremy Hylton | d08b4c4 | 2000-06-23 19:37:02 +0000 | [diff] [blame] | 351 | |
Fred Drake | 41deb1e | 2001-02-01 05:27:45 +0000 | [diff] [blame] | 352 | /* Test if a type supports weak references */ |
Guido van Rossum | 3cf5b1e | 2006-07-27 21:53:35 +0000 | [diff] [blame] | 353 | #define PyType_SUPPORTS_WEAKREFS(t) ((t)->tp_weaklistoffset > 0) |
Fred Drake | 41deb1e | 2001-02-01 05:27:45 +0000 | [diff] [blame] | 354 | |
| 355 | #define PyObject_GET_WEAKREFS_LISTPTR(o) \ |
Antoine Pitrou | f95a1b3 | 2010-05-09 15:52:27 +0000 | [diff] [blame] | 356 | ((PyObject **) (((char *) (o)) + Py_TYPE(o)->tp_weaklistoffset)) |
Fred Drake | 41deb1e | 2001-02-01 05:27:45 +0000 | [diff] [blame] | 357 | |
Guido van Rossum | a330996 | 1993-07-28 09:05:47 +0000 | [diff] [blame] | 358 | #ifdef __cplusplus |
| 359 | } |
| 360 | #endif |
| 361 | #endif /* !Py_OBJIMPL_H */ |