The C and C++ Include Header Files

/usr/include/malloc.h


$ cat -n /usr/include/malloc.h

     1	/* Prototypes and definition for malloc implementation.
     2	   Copyright (C) 1996-2024 Free Software Foundation, Inc.
     3	   Copyright The GNU Toolchain Authors.
     4	   This file is part of the GNU C Library.
     5	
     6	   The GNU C Library is free software; you can redistribute it and/or
     7	   modify it under the terms of the GNU Lesser General Public
     8	   License as published by the Free Software Foundation; either
     9	   version 2.1 of the License, or (at your option) any later version.
    10	
    11	   The GNU C Library is distributed in the hope that it will be useful,
    12	   but WITHOUT ANY WARRANTY; without even the implied warranty of
    13	   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    14	   Lesser General Public License for more details.
    15	
    16	   You should have received a copy of the GNU Lesser General Public
    17	   License along with the GNU C Library; if not, see
    18	   <https://www.gnu.org/licenses/>.  */
    19	
    20	#ifndef _MALLOC_H
    21	#define _MALLOC_H 1
    22	
    23	#include <features.h>
    24	#include <stddef.h>
    25	#include <stdio.h>
    26	
    27	#ifdef _LIBC
    28	# define __MALLOC_HOOK_VOLATILE
    29	# define __MALLOC_DEPRECATED
    30	#else
    31	# define __MALLOC_HOOK_VOLATILE volatile
    32	# define __MALLOC_DEPRECATED __attribute_deprecated__
    33	#endif
    34	
    35	
    36	__BEGIN_DECLS
    37	
    38	/* Allocate SIZE bytes of memory.  */
    39	extern void *malloc (size_t __size) __THROW __attribute_malloc__
    40	     __attribute_alloc_size__ ((1)) __wur;
    41	
    42	/* Allocate NMEMB elements of SIZE bytes each, all initialized to 0.  */
    43	extern void *calloc (size_t __nmemb, size_t __size)
    44	__THROW __attribute_malloc__ __attribute_alloc_size__ ((1, 2)) __wur;
    45	
    46	/* Re-allocate the previously allocated block in __ptr, making the new
    47	   block SIZE bytes long.  */
    48	/* __attribute_malloc__ is not used, because if realloc returns
    49	   the same pointer that was passed to it, aliasing needs to be allowed
    50	   between objects pointed by the old and new pointers.  */
    51	extern void *realloc (void *__ptr, size_t __size)
    52	__THROW __attribute_warn_unused_result__ __attribute_alloc_size__ ((2));
    53	
    54	/* Re-allocate the previously allocated block in PTR, making the new
    55	   block large enough for NMEMB elements of SIZE bytes each.  */
    56	/* __attribute_malloc__ is not used, because if reallocarray returns
    57	   the same pointer that was passed to it, aliasing needs to be allowed
    58	   between objects pointed by the old and new pointers.  */
    59	extern void *reallocarray (void *__ptr, size_t __nmemb, size_t __size)
    60	  __THROW __attribute_warn_unused_result__ __attribute_alloc_size__ ((2, 3))
    61	  __attr_dealloc_free;
    62	
    63	/* Free a block allocated by `malloc', `realloc' or `calloc'.  */
    64	extern void free (void *__ptr) __THROW;
    65	
    66	/* Allocate SIZE bytes allocated to ALIGNMENT bytes.  */
    67	extern void *memalign (size_t __alignment, size_t __size)
    68	  __THROW __attribute_malloc__ __attribute_alloc_align__ ((1))
    69	  __attribute_alloc_size__ ((2)) __wur __attr_dealloc_free;
    70	
    71	/* Allocate SIZE bytes on a page boundary.  */
    72	extern void *valloc (size_t __size) __THROW __attribute_malloc__
    73	     __attribute_alloc_size__ ((1)) __wur __attr_dealloc_free;
    74	
    75	/* Equivalent to valloc(minimum-page-that-holds(n)), that is, round up
    76	   __size to nearest pagesize. */
    77	extern void *pvalloc (size_t __size) __THROW __attribute_malloc__
    78	  __wur __attr_dealloc_free;
    79	
    80	/* SVID2/XPG mallinfo structure */
    81	
    82	struct mallinfo
    83	{
    84	  int arena;    /* non-mmapped space allocated from system */
    85	  int ordblks;  /* number of free chunks */
    86	  int smblks;   /* number of fastbin blocks */
    87	  int hblks;    /* number of mmapped regions */
    88	  int hblkhd;   /* space in mmapped regions */
    89	  int usmblks;  /* always 0, preserved for backwards compatibility */
    90	  int fsmblks;  /* space available in freed fastbin blocks */
    91	  int uordblks; /* total allocated space */
    92	  int fordblks; /* total free space */
    93	  int keepcost; /* top-most, releasable (via malloc_trim) space */
    94	};
    95	
    96	/* SVID2/XPG mallinfo2 structure which can handle allocations
    97	   bigger than 4GB.  */
    98	
    99	struct mallinfo2
   100	{
   101	  size_t arena;    /* non-mmapped space allocated from system */
   102	  size_t ordblks;  /* number of free chunks */
   103	  size_t smblks;   /* number of fastbin blocks */
   104	  size_t hblks;    /* number of mmapped regions */
   105	  size_t hblkhd;   /* space in mmapped regions */
   106	  size_t usmblks;  /* always 0, preserved for backwards compatibility */
   107	  size_t fsmblks;  /* space available in freed fastbin blocks */
   108	  size_t uordblks; /* total allocated space */
   109	  size_t fordblks; /* total free space */
   110	  size_t keepcost; /* top-most, releasable (via malloc_trim) space */
   111	};
   112	
   113	/* Returns a copy of the updated current mallinfo. */
   114	extern struct mallinfo mallinfo (void) __THROW __MALLOC_DEPRECATED;
   115	
   116	/* Returns a copy of the updated current mallinfo. */
   117	extern struct mallinfo2 mallinfo2 (void) __THROW;
   118	
   119	/* SVID2/XPG mallopt options */
   120	#ifndef M_MXFAST
   121	# define M_MXFAST  1    /* maximum request size for "fastbins" */
   122	#endif
   123	#ifndef M_NLBLKS
   124	# define M_NLBLKS  2    /* UNUSED in this malloc */
   125	#endif
   126	#ifndef M_GRAIN
   127	# define M_GRAIN   3    /* UNUSED in this malloc */
   128	#endif
   129	#ifndef M_KEEP
   130	# define M_KEEP    4    /* UNUSED in this malloc */
   131	#endif
   132	
   133	/* mallopt options that actually do something */
   134	#define M_TRIM_THRESHOLD    -1
   135	#define M_TOP_PAD           -2
   136	#define M_MMAP_THRESHOLD    -3
   137	#define M_MMAP_MAX          -4
   138	#define M_CHECK_ACTION      -5
   139	#define M_PERTURB           -6
   140	#define M_ARENA_TEST        -7
   141	#define M_ARENA_MAX         -8
   142	
   143	/* General SVID/XPG interface to tunable parameters. */
   144	extern int mallopt (int __param, int __val) __THROW;
   145	
   146	/* Release all but __pad bytes of freed top-most memory back to the
   147	   system. Return 1 if successful, else 0. */
   148	extern int malloc_trim (size_t __pad) __THROW;
   149	
   150	/* Report the number of usable allocated bytes associated with allocated
   151	   chunk __ptr. */
   152	extern size_t malloc_usable_size (void *__ptr) __THROW;
   153	
   154	/* Prints brief summary statistics on stderr. */
   155	extern void malloc_stats (void) __THROW;
   156	
   157	/* Output information about state of allocator to stream FP.  */
   158	extern int malloc_info (int __options, FILE *__fp) __THROW;
   159	
   160	__END_DECLS
   161	#endif /* malloc.h */