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The C and C++ Include Header Files

/usr/include/python3.12/internal/pycore_pymem.h


$ cat -n /usr/include/python3.12/internal/pycore_pymem.h

     1	#ifndef Py_INTERNAL_PYMEM_H
     2	#define Py_INTERNAL_PYMEM_H
     3	#ifdef __cplusplus
     4	extern "C" {
     5	#endif
     6	
     7	#ifndef Py_BUILD_CORE
     8	#  error "this header requires Py_BUILD_CORE define"
     9	#endif
    10	
    11	#include "pymem.h"      // PyMemAllocatorName
    12	
    13	
    14	typedef struct {
    15	    /* We tag each block with an API ID in order to tag API violations */
    16	    char api_id;
    17	    PyMemAllocatorEx alloc;
    18	} debug_alloc_api_t;
    19	
    20	struct _pymem_allocators {
    21	    PyThread_type_lock mutex;
    22	    struct {
    23	        PyMemAllocatorEx raw;
    24	        PyMemAllocatorEx mem;
    25	        PyMemAllocatorEx obj;
    26	    } standard;
    27	    struct {
    28	        debug_alloc_api_t raw;
    29	        debug_alloc_api_t mem;
    30	        debug_alloc_api_t obj;
    31	    } debug;
    32	    PyObjectArenaAllocator obj_arena;
    33	};
    34	
    35	
    36	/* Set the memory allocator of the specified domain to the default.
    37	   Save the old allocator into *old_alloc if it's non-NULL.
    38	   Return on success, or return -1 if the domain is unknown. */
    39	PyAPI_FUNC(int) _PyMem_SetDefaultAllocator(
    40	    PyMemAllocatorDomain domain,
    41	    PyMemAllocatorEx *old_alloc);
    42	
    43	/* Special bytes broadcast into debug memory blocks at appropriate times.
    44	   Strings of these are unlikely to be valid addresses, floats, ints or
    45	   7-bit ASCII.
    46	
    47	   - PYMEM_CLEANBYTE: clean (newly allocated) memory
    48	   - PYMEM_DEADBYTE dead (newly freed) memory
    49	   - PYMEM_FORBIDDENBYTE: untouchable bytes at each end of a block
    50	
    51	   Byte patterns 0xCB, 0xDB and 0xFB have been replaced with 0xCD, 0xDD and
    52	   0xFD to use the same values than Windows CRT debug malloc() and free().
    53	   If modified, _PyMem_IsPtrFreed() should be updated as well. */
    54	#define PYMEM_CLEANBYTE      0xCD
    55	#define PYMEM_DEADBYTE       0xDD
    56	#define PYMEM_FORBIDDENBYTE  0xFD
    57	
    58	/* Heuristic checking if a pointer value is newly allocated
    59	   (uninitialized), newly freed or NULL (is equal to zero).
    60	
    61	   The pointer is not dereferenced, only the pointer value is checked.
    62	
    63	   The heuristic relies on the debug hooks on Python memory allocators which
    64	   fills newly allocated memory with CLEANBYTE (0xCD) and newly freed memory
    65	   with DEADBYTE (0xDD). Detect also "untouchable bytes" marked
    66	   with FORBIDDENBYTE (0xFD). */
    67	static inline int _PyMem_IsPtrFreed(const void *ptr)
    68	{
    69	    uintptr_t value = (uintptr_t)ptr;
    70	#if SIZEOF_VOID_P == 8
    71	    return (value == 0
    72	            || value == (uintptr_t)0xCDCDCDCDCDCDCDCD
    73	            || value == (uintptr_t)0xDDDDDDDDDDDDDDDD
    74	            || value == (uintptr_t)0xFDFDFDFDFDFDFDFD);
    75	#elif SIZEOF_VOID_P == 4
    76	    return (value == 0
    77	            || value == (uintptr_t)0xCDCDCDCD
    78	            || value == (uintptr_t)0xDDDDDDDD
    79	            || value == (uintptr_t)0xFDFDFDFD);
    80	#else
    81	#  error "unknown pointer size"
    82	#endif
    83	}
    84	
    85	PyAPI_FUNC(int) _PyMem_GetAllocatorName(
    86	    const char *name,
    87	    PyMemAllocatorName *allocator);
    88	
    89	/* Configure the Python memory allocators.
    90	   Pass PYMEM_ALLOCATOR_DEFAULT to use default allocators.
    91	   PYMEM_ALLOCATOR_NOT_SET does nothing. */
    92	PyAPI_FUNC(int) _PyMem_SetupAllocators(PyMemAllocatorName allocator);
    93	
    94	
    95	#ifdef __cplusplus
    96	}
    97	#endif
    98	#endif /* !Py_INTERNAL_PYMEM_H */