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comparison CSP2/CSP2_env/env-d9b9114564458d9d-741b3de822f2aaca6c6caa4325c4afce/include/python3.8/pymem.h @ 69:33d812a61356

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planemo upload commit 2e9511a184a1ca667c7be0c6321a36dc4e3d116d
author jpayne
date Tue, 18 Mar 2025 17:55:14 -0400
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67:0e9998148a16 69:33d812a61356
1 /* The PyMem_ family: low-level memory allocation interfaces.
2 See objimpl.h for the PyObject_ memory family.
3 */
4
5 #ifndef Py_PYMEM_H
6 #define Py_PYMEM_H
7
8 #include "pyport.h"
9
10 #ifdef __cplusplus
11 extern "C" {
12 #endif
13
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 PyMem_ with calls to the platform malloc/realloc/
23 calloc/free. For example, on Windows different DLLs may end up using
24 different heaps, and if you use PyMem_Malloc you'll get the memory from the
25 heap used by the Python DLL; it could be a disaster if you free()'ed that
26 directly in your own extension. Using PyMem_Free instead ensures Python
27 can return the memory to the proper heap. As another example, in
28 PYMALLOC_DEBUG mode, Python wraps all calls to all PyMem_ and PyObject_
29 memory functions in special debugging wrappers that add additional
30 debugging info to dynamic memory blocks. The system routines have no idea
31 what to do with that stuff, and the Python wrappers have no idea what to do
32 with raw blocks obtained directly by the system routines then.
33
34 The GIL must be held when using these APIs.
35 */
36
37 /*
38 * Raw memory interface
39 * ====================
40 */
41
42 /* Functions
43
44 Functions supplying platform-independent semantics for malloc/realloc/
45 free. These functions make sure that allocating 0 bytes returns a distinct
46 non-NULL pointer (whenever possible -- if we're flat out of memory, NULL
47 may be returned), even if the platform malloc and realloc don't.
48 Returned pointers must be checked for NULL explicitly. No action is
49 performed on failure (no exception is set, no warning is printed, etc).
50 */
51
52 PyAPI_FUNC(void *) PyMem_Malloc(size_t size);
53 PyAPI_FUNC(void *) PyMem_Realloc(void *ptr, size_t new_size);
54 PyAPI_FUNC(void) PyMem_Free(void *ptr);
55
56 /* Macros. */
57
58 /* PyMem_MALLOC(0) means malloc(1). Some systems would return NULL
59 for malloc(0), which would be treated as an error. Some platforms
60 would return a pointer with no memory behind it, which would break
61 pymalloc. To solve these problems, allocate an extra byte. */
62 /* Returns NULL to indicate error if a negative size or size larger than
63 Py_ssize_t can represent is supplied. Helps prevents security holes. */
64 #define PyMem_MALLOC(n) PyMem_Malloc(n)
65 #define PyMem_REALLOC(p, n) PyMem_Realloc(p, n)
66 #define PyMem_FREE(p) PyMem_Free(p)
67
68 /*
69 * Type-oriented memory interface
70 * ==============================
71 *
72 * Allocate memory for n objects of the given type. Returns a new pointer
73 * or NULL if the request was too large or memory allocation failed. Use
74 * these macros rather than doing the multiplication yourself so that proper
75 * overflow checking is always done.
76 */
77
78 #define PyMem_New(type, n) \
79 ( ((size_t)(n) > PY_SSIZE_T_MAX / sizeof(type)) ? NULL : \
80 ( (type *) PyMem_Malloc((n) * sizeof(type)) ) )
81 #define PyMem_NEW(type, n) \
82 ( ((size_t)(n) > PY_SSIZE_T_MAX / sizeof(type)) ? NULL : \
83 ( (type *) PyMem_MALLOC((n) * sizeof(type)) ) )
84
85 /*
86 * The value of (p) is always clobbered by this macro regardless of success.
87 * The caller MUST check if (p) is NULL afterwards and deal with the memory
88 * error if so. This means the original value of (p) MUST be saved for the
89 * caller's memory error handler to not lose track of it.
90 */
91 #define PyMem_Resize(p, type, n) \
92 ( (p) = ((size_t)(n) > PY_SSIZE_T_MAX / sizeof(type)) ? NULL : \
93 (type *) PyMem_Realloc((p), (n) * sizeof(type)) )
94 #define PyMem_RESIZE(p, type, n) \
95 ( (p) = ((size_t)(n) > PY_SSIZE_T_MAX / sizeof(type)) ? NULL : \
96 (type *) PyMem_REALLOC((p), (n) * sizeof(type)) )
97
98 /* PyMem{Del,DEL} are left over from ancient days, and shouldn't be used
99 * anymore. They're just confusing aliases for PyMem_{Free,FREE} now.
100 */
101 #define PyMem_Del PyMem_Free
102 #define PyMem_DEL PyMem_FREE
103
104 /* bpo-35053: expose _Py_tracemalloc_config for performance:
105 _Py_NewReference() needs an efficient check to test if tracemalloc is
106 tracing.
107
108 It has to be defined in pymem.h, before object.h is included. */
109 struct _PyTraceMalloc_Config {
110 /* Module initialized?
111 Variable protected by the GIL */
112 enum {
113 TRACEMALLOC_NOT_INITIALIZED,
114 TRACEMALLOC_INITIALIZED,
115 TRACEMALLOC_FINALIZED
116 } initialized;
117
118 /* Is tracemalloc tracing memory allocations?
119 Variable protected by the GIL */
120 int tracing;
121
122 /* limit of the number of frames in a traceback, 1 by default.
123 Variable protected by the GIL. */
124 int max_nframe;
125
126 /* use domain in trace key?
127 Variable protected by the GIL. */
128 int use_domain;
129 };
130
131 PyAPI_DATA(struct _PyTraceMalloc_Config) _Py_tracemalloc_config;
132
133 #define _PyTraceMalloc_Config_INIT \
134 {.initialized = TRACEMALLOC_NOT_INITIALIZED, \
135 .tracing = 0, \
136 .max_nframe = 1, \
137 .use_domain = 0}
138
139
140 #ifndef Py_LIMITED_API
141 # define Py_CPYTHON_PYMEM_H
142 # include "cpython/pymem.h"
143 # undef Py_CPYTHON_PYMEM_H
144 #endif
145
146 #ifdef __cplusplus
147 }
148 #endif
149
150 #endif /* !Py_PYMEM_H */