malloc.c

一个很好的内存泄露的监测代码

#ifndef MALLOC_ALIGNMENT
#define MALLOC_ALIGNMENT       (2 * SIZE_SZ)
#endif

/* The corresponding bit mask value */
#define MALLOC_ALIGN_MASK      (MALLOC_ALIGNMENT - 1)



/*
  REALLOC_ZERO_BYTES_FREES should be set if a call to
  realloc with zero bytes should be the same as a call to free.
  This is required by the C standard. Otherwise, since this malloc
  returns a unique pointer for malloc(0), so does realloc(p, 0).
*/

#ifndef REALLOC_ZERO_BYTES_FREES
#define REALLOC_ZERO_BYTES_FREES 1
#endif

/*
  TRIM_FASTBINS controls whether free() of a very small chunk can
  immediately lead to trimming. Setting to true (1) can reduce memory
  footprint, but will almost always slow down programs that use a lot
  of small chunks.

  Define this only if you are willing to give up some speed to more
  aggressively reduce system-level memory footprint when releasing
  memory in programs that use many small chunks.  You can get
  essentially the same effect by setting MXFAST to 0, but this can
  lead to even greater slowdowns in programs using many small chunks.
  TRIM_FASTBINS is an in-between compile-time option, that disables
  only those chunks bordering topmost memory from being placed in
  fastbins.
*/

#ifndef TRIM_FASTBINS
#define TRIM_FASTBINS  0
#endif


/*
  USE_DL_PREFIX will prefix all public routines with the string 'dl'.
  This is necessary when you only want to use this malloc in one part
  of a program, using your regular system malloc elsewhere.
*/

/* #define USE_DL_PREFIX */


/*
   Two-phase name translation.
   All of the actual routines are given mangled names.
   When wrappers are used, they become the public callable versions.
   When DL_PREFIX is used, the callable names are prefixed.
*/

#ifdef USE_DL_PREFIX
#define public_cALLOc    dlcalloc
#define public_fREe      dlfree
#define public_cFREe     dlcfree
#define public_mALLOc    dlmalloc
#define public_mEMALIGn  dlmemalign
#define public_rEALLOc   dlrealloc
#define public_vALLOc    dlvalloc
#define public_pVALLOc   dlpvalloc
#define public_mALLINFo  dlmallinfo
#define public_mALLOPt   dlmallopt
#define public_mTRIm     dlmalloc_trim
#define public_mSTATs    dlmalloc_stats
#define public_mUSABLe   dlmalloc_usable_size
#define public_iCALLOc   dlindependent_calloc
#define public_iCOMALLOc dlindependent_comalloc
#define public_gET_STATe dlget_state
#define public_sET_STATe dlset_state
#else /* USE_DL_PREFIX */
#ifdef _LIBC

/* Special defines for the GNU C library.  */
#define public_cALLOc    __libc_calloc
#define public_fREe      __libc_free
#define public_cFREe     __libc_cfree
#define public_mALLOc    __libc_malloc
#define public_mEMALIGn  __libc_memalign
#define public_rEALLOc   __libc_realloc
#define public_vALLOc    __libc_valloc
#define public_pVALLOc   __libc_pvalloc
#define public_mALLINFo  __libc_mallinfo
#define public_mALLOPt   __libc_mallopt
#define public_mTRIm     __malloc_trim
#define public_mSTATs    __malloc_stats
#define public_mUSABLe   __malloc_usable_size
#define public_iCALLOc   __libc_independent_calloc
#define public_iCOMALLOc __libc_independent_comalloc
#define public_gET_STATe __malloc_get_state
#define public_sET_STATe __malloc_set_state
#define malloc_getpagesize __getpagesize()
#define open             __open
#define mmap             __mmap
#define munmap           __munmap
#define mremap           __mremap
#define mprotect         __mprotect
#define MORECORE         (*__morecore)
#define MORECORE_FAILURE 0

Void_t * __default_morecore (ptrdiff_t);
Void_t *(*__morecore)(ptrdiff_t) = __default_morecore;

#else /* !_LIBC */
#define public_cALLOc    calloc
#define public_fREe      free
#define public_cFREe     cfree
#define public_mALLOc    malloc
#define public_mEMALIGn  memalign
#define public_rEALLOc   realloc
#define public_vALLOc    valloc
#define public_pVALLOc   pvalloc
#define public_mALLINFo  mallinfo
#define public_mALLOPt   mallopt
#define public_mTRIm     malloc_trim
#define public_mSTATs    malloc_stats
#define public_mUSABLe   malloc_usable_size
#define public_iCALLOc   independent_calloc
#define public_iCOMALLOc independent_comalloc
#define public_gET_STATe malloc_get_state
#define public_sET_STATe malloc_set_state
#endif /* _LIBC */
#endif /* USE_DL_PREFIX */


#if !defined _LIBC && (!defined __GNUC__ || __GNUC__<3)
#define __builtin_expect(expr, val) (expr)
#endif

/*
  HAVE_MEMCPY should be defined if you are not otherwise using
  ANSI STD C, but still have memcpy and memset in your C library
  and want to use them in calloc and realloc. Otherwise simple
  macro versions are defined below.

  USE_MEMCPY should be defined as 1 if you actually want to
  have memset and memcpy called. People report that the macro
  versions are faster than libc versions on some systems.

  Even if USE_MEMCPY is set to 1, loops to copy/clear small chunks
  (of <= 36 bytes) are manually unrolled in realloc and calloc.
*/

#define HAVE_MEMCPY

#ifndef USE_MEMCPY
#ifdef HAVE_MEMCPY
#define USE_MEMCPY 1
#else
#define USE_MEMCPY 0
#endif
#endif


#if (__STD_C || defined(HAVE_MEMCPY))

#ifdef _LIBC
# include <string.h>
#else
#ifdef WIN32
/* On Win32 memset and memcpy are already declared in windows.h */
#else
#if __STD_C
void* memset(void*, int, size_t);
void* memcpy(void*, const void*, size_t);
#else
Void_t* memset();
Void_t* memcpy();
#endif
#endif
#endif
#endif

/*
  MALLOC_FAILURE_ACTION is the action to take before "return 0" when
  malloc fails to be able to return memory, either because memory is
  exhausted or because of illegal arguments.

  By default, sets errno if running on STD_C platform, else does nothing.
*/

#ifndef MALLOC_FAILURE_ACTION
#if __STD_C
#define MALLOC_FAILURE_ACTION \
   errno = ENOMEM;

#else
#define MALLOC_FAILURE_ACTION
#endif
#endif

/*
  MORECORE-related declarations. By default, rely on sbrk
*/


#ifdef LACKS_UNISTD_H
#if !defined(__FreeBSD__) && !defined(__OpenBSD__) && !defined(__NetBSD__)
#if __STD_C
extern Void_t*     sbrk(ptrdiff_t);
#else
extern Void_t*     sbrk();
#endif
#endif
#endif

/*
  MORECORE is the name of the routine to call to obtain more memory
  from the system.  See below for general guidance on writing
  alternative MORECORE functions, as well as a version for WIN32 and a
  sample version for pre-OSX macos.
*/

#ifndef MORECORE
#define MORECORE sbrk
#endif

/*
  MORECORE_FAILURE is the value returned upon failure of MORECORE
  as well as mmap. Since it cannot be an otherwise valid memory address,
  and must reflect values of standard sys calls, you probably ought not
  try to redefine it.
*/

#ifndef MORECORE_FAILURE
#define MORECORE_FAILURE (-1)
#endif

/*
  If MORECORE_CONTIGUOUS is true, take advantage of fact that
  consecutive calls to MORECORE with positive arguments always return
  contiguous increasing addresses.  This is true of unix sbrk.  Even
  if not defined, when regions happen to be contiguous, malloc will
  permit allocations spanning regions obtained from different
  calls. But defining this when applicable enables some stronger
  consistency checks and space efficiencies.
*/

#ifndef MORECORE_CONTIGUOUS
#define MORECORE_CONTIGUOUS 1
#endif

/*
  Define MORECORE_CANNOT_TRIM if your version of MORECORE
  cannot release space back to the system when given negative
  arguments. This is generally necessary only if you are using
  a hand-crafted MORECORE function that cannot handle negative arguments.
*/

/* #define MORECORE_CANNOT_TRIM */

/*  MORECORE_CLEARS           (default 1)
     The degree to which the routine mapped to MORECORE zeroes out
     memory: never (0), only for newly allocated space (1) or always
     (2).  The distinction between (1) and (2) is necessary because on
     some systems, if the application first decrements and then
     increments the break value, the contents of the reallocated space
     are unspecified.
*/

#ifndef MORECORE_CLEARS
#define MORECORE_CLEARS 1
#endif


/*
  Define HAVE_MMAP as true to optionally make malloc() use mmap() to
  allocate very large blocks.  These will be returned to the
  operating system immediately after a free(). Also, if mmap
  is available, it is used as a backup strategy in cases where
  MORECORE fails to provide space from system.

  This malloc is best tuned to work with mmap for large requests.
  If you do not have mmap, operations involving very large chunks (1MB
  or so) may be slower than you'd like.
*/

#ifndef HAVE_MMAP
#define HAVE_MMAP 1

/*
   Standard unix mmap using /dev/zero clears memory so calloc doesn't
   need to.
*/

#ifndef MMAP_CLEARS
#define MMAP_CLEARS 1
#endif

#else /* no mmap */
#ifndef MMAP_CLEARS
#define MMAP_CLEARS 0
#endif
#endif


/*
   MMAP_AS_MORECORE_SIZE is the minimum mmap size argument to use if
   sbrk fails, and mmap is used as a backup (which is done only if
   HAVE_MMAP).  The value must be a multiple of page size.  This
   backup strategy generally applies only when systems have "holes" in
   address space, so sbrk cannot perform contiguous expansion, but
   there is still space available on system.  On systems for which
   this is known to be useful (i.e. most linux kernels), this occurs
   only when programs allocate huge amounts of memory.  Between this,
   and the fact that mmap regions tend to be limited, the size should
   be large, to avoid too many mmap calls and thus avoid running out
   of kernel resources.
*/

#ifndef MMAP_AS_MORECORE_SIZE
#define MMAP_AS_MORECORE_SIZE (1024 * 1024)
#endif

/*
  Define HAVE_MREMAP to make realloc() use mremap() to re-allocate
  large blocks.  This is currently only possible on Linux with
  kernel versions newer than 1.3.77.
*/

#ifndef HAVE_MREMAP
#ifdef linux
#define HAVE_MREMAP 1
#else
#define HAVE_MREMAP 0
#endif

#endif /* HAVE_MMAP */

/* Define USE_ARENAS to enable support for multiple `arenas'.  These
   are allocated using mmap(), are necessary for threads and
   occasionally useful to overcome address space limitations affecting
   sbrk(). */

#ifndef USE_ARENAS
#define USE_ARENAS HAVE_MMAP
#endif

/* USE_STARTER determines if and when the special "starter" hook
   functions are used: not at all (0), during ptmalloc_init (first bit
   set), or from the beginning until an explicit call to ptmalloc_init
   (second bit set).  This is necessary if thread-related
   initialization functions (e.g.  pthread_key_create) require
   malloc() calls (set USE_STARTER=1), or if those functions initially
   cannot be used at all (set USE_STARTER=2 and perform an explicit
   ptmalloc_init() when the thread library is ready, typically at the
   start of main()). */

#ifndef USE_STARTER
# ifndef _LIBC
#  define USE_STARTER 1
# else
#  if USE___THREAD || (defined USE_TLS && !defined SHARED)
    /* These routines are never needed in this configuration.  */
#   define USE_STARTER 0
#  else
#   define USE_STARTER (USE_TLS ? 4 : 1)
#  endif
# endif
#endif