--- /dev/null
+/*
+ A version of malloc/free/realloc written by Doug Lea and released to the
+ public domain. Send questions/comments/complaints/performance data
+ to dl@cs.oswego.edu
+
+* VERSION 2.6.6 Sun Mar 5 19:10:03 2000 Doug Lea (dl at gee)
+
+ Note: There may be an updated version of this malloc obtainable at
+ ftp://g.oswego.edu/pub/misc/malloc.c
+ Check before installing!
+
+* Why use this malloc?
+
+ This is not the fastest, most space-conserving, most portable, or
+ most tunable malloc ever written. However it is among the fastest
+ while also being among the most space-conserving, portable and tunable.
+ Consistent balance across these factors results in a good general-purpose
+ allocator. For a high-level description, see
+ http://g.oswego.edu/dl/html/malloc.html
+
+* Synopsis of public routines
+
+ (Much fuller descriptions are contained in the program documentation below.)
+
+ malloc(size_t n);
+ Return a pointer to a newly allocated chunk of at least n bytes, or null
+ if no space is available.
+ free(Void_t* p);
+ Release the chunk of memory pointed to by p, or no effect if p is null.
+ realloc(Void_t* p, size_t n);
+ Return a pointer to a chunk of size n that contains the same data
+ as does chunk p up to the minimum of (n, p's size) bytes, or null
+ if no space is available. The returned pointer may or may not be
+ the same as p. If p is null, equivalent to malloc. Unless the
+ #define REALLOC_ZERO_BYTES_FREES below is set, realloc with a
+ size argument of zero (re)allocates a minimum-sized chunk.
+ memalign(size_t alignment, size_t n);
+ Return a pointer to a newly allocated chunk of n bytes, aligned
+ in accord with the alignment argument, which must be a power of
+ two.
+ valloc(size_t n);
+ Equivalent to memalign(pagesize, n), where pagesize is the page
+ size of the system (or as near to this as can be figured out from
+ all the includes/defines below.)
+ pvalloc(size_t n);
+ Equivalent to valloc(minimum-page-that-holds(n)), that is,
+ round up n to nearest pagesize.
+ calloc(size_t unit, size_t quantity);
+ Returns a pointer to quantity * unit bytes, with all locations
+ set to zero.
+ cfree(Void_t* p);
+ Equivalent to free(p).
+ malloc_trim(size_t pad);
+ Release all but pad bytes of freed top-most memory back
+ to the system. Return 1 if successful, else 0.
+ malloc_usable_size(Void_t* p);
+ Report the number usable allocated bytes associated with allocated
+ chunk p. This may or may not report more bytes than were requested,
+ due to alignment and minimum size constraints.
+ malloc_stats();
+ Prints brief summary statistics on stderr.
+ mallinfo()
+ Returns (by copy) a struct containing various summary statistics.
+ mallopt(int parameter_number, int parameter_value)
+ Changes one of the tunable parameters described below. Returns
+ 1 if successful in changing the parameter, else 0.
+
+* Vital statistics:
+
+ Alignment: 8-byte
+ 8 byte alignment is currently hardwired into the design. This
+ seems to suffice for all current machines and C compilers.
+
+ Assumed pointer representation: 4 or 8 bytes
+ Code for 8-byte pointers is untested by me but has worked
+ reliably by Wolfram Gloger, who contributed most of the
+ changes supporting this.
+
+ Assumed size_t representation: 4 or 8 bytes
+ Note that size_t is allowed to be 4 bytes even if pointers are 8.
+
+ Minimum overhead per allocated chunk: 4 or 8 bytes
+ Each malloced chunk has a hidden overhead of 4 bytes holding size
+ and status information.
+
+ Minimum allocated size: 4-byte ptrs: 16 bytes (including 4 overhead)
+ 8-byte ptrs: 24/32 bytes (including, 4/8 overhead)
+
+ When a chunk is freed, 12 (for 4byte ptrs) or 20 (for 8 byte
+ ptrs but 4 byte size) or 24 (for 8/8) additional bytes are
+ needed; 4 (8) for a trailing size field
+ and 8 (16) bytes for free list pointers. Thus, the minimum
+ allocatable size is 16/24/32 bytes.
+
+ Even a request for zero bytes (i.e., malloc(0)) returns a
+ pointer to something of the minimum allocatable size.
+
+ Maximum allocated size: 4-byte size_t: 2^31 - 8 bytes
+ 8-byte size_t: 2^63 - 16 bytes
+
+ It is assumed that (possibly signed) size_t bit values suffice to
+ represent chunk sizes. `Possibly signed' is due to the fact
+ that `size_t' may be defined on a system as either a signed or
+ an unsigned type. To be conservative, values that would appear
+ as negative numbers are avoided.
+ Requests for sizes with a negative sign bit when the request
+ size is treaded as a long will return null.
+
+ Maximum overhead wastage per allocated chunk: normally 15 bytes
+
+ Alignnment demands, plus the minimum allocatable size restriction
+ make the normal worst-case wastage 15 bytes (i.e., up to 15
+ more bytes will be allocated than were requested in malloc), with
+ two exceptions:
+ 1. Because requests for zero bytes allocate non-zero space,
+ the worst case wastage for a request of zero bytes is 24 bytes.
+ 2. For requests >= mmap_threshold that are serviced via
+ mmap(), the worst case wastage is 8 bytes plus the remainder
+ from a system page (the minimal mmap unit); typically 4096 bytes.
+
+* Limitations
+
+ Here are some features that are NOT currently supported
+
+ * No user-definable hooks for callbacks and the like.
+ * No automated mechanism for fully checking that all accesses
+ to malloced memory stay within their bounds.
+ * No support for compaction.
+
+* Synopsis of compile-time options:
+
+ People have reported using previous versions of this malloc on all
+ versions of Unix, sometimes by tweaking some of the defines
+ below. It has been tested most extensively on Solaris and
+ Linux. It is also reported to work on WIN32 platforms.
+ People have also reported adapting this malloc for use in
+ stand-alone embedded systems.
+
+ The implementation is in straight, hand-tuned ANSI C. Among other
+ consequences, it uses a lot of macros. Because of this, to be at
+ all usable, this code should be compiled using an optimizing compiler
+ (for example gcc -O2) that can simplify expressions and control
+ paths.
+
+ __STD_C (default: derived from C compiler defines)
+ Nonzero if using ANSI-standard C compiler, a C++ compiler, or
+ a C compiler sufficiently close to ANSI to get away with it.
+ DEBUG (default: NOT defined)
+ Define to enable debugging. Adds fairly extensive assertion-based
+ checking to help track down memory errors, but noticeably slows down
+ execution.
+ REALLOC_ZERO_BYTES_FREES (default: NOT defined)
+ Define this if you think that realloc(p, 0) should be equivalent
+ to free(p). Otherwise, since malloc returns a unique pointer for
+ malloc(0), so does realloc(p, 0).
+ HAVE_MEMCPY (default: defined)
+ Define if you are not otherwise using ANSI STD C, but still
+ have memcpy and memset in your C library and want to use them.
+ Otherwise, simple internal versions are supplied.
+ USE_MEMCPY (default: 1 if HAVE_MEMCPY is defined, 0 otherwise)
+ Define as 1 if you want the C library versions of memset and
+ memcpy called in realloc and calloc (otherwise macro versions are used).
+ At least on some platforms, the simple macro versions usually
+ outperform libc versions.
+ HAVE_MMAP (default: defined as 1)
+ Define to non-zero to optionally make malloc() use mmap() to
+ allocate very large blocks.
+ HAVE_MREMAP (default: defined as 0 unless Linux libc set)
+ Define to non-zero to optionally make realloc() use mremap() to
+ reallocate very large blocks.
+ malloc_getpagesize (default: derived from system #includes)
+ Either a constant or routine call returning the system page size.
+ HAVE_USR_INCLUDE_MALLOC_H (default: NOT defined)
+ Optionally define if you are on a system with a /usr/include/malloc.h
+ that declares struct mallinfo. It is not at all necessary to
+ define this even if you do, but will ensure consistency.
+ INTERNAL_SIZE_T (default: size_t)
+ Define to a 32-bit type (probably `unsigned int') if you are on a
+ 64-bit machine, yet do not want or need to allow malloc requests of
+ greater than 2^31 to be handled. This saves space, especially for
+ very small chunks.
+ INTERNAL_LINUX_C_LIB (default: NOT defined)
+ Defined only when compiled as part of Linux libc.
+ Also note that there is some odd internal name-mangling via defines
+ (for example, internally, `malloc' is named `mALLOc') needed
+ when compiling in this case. These look funny but don't otherwise
+ affect anything.
+ WIN32 (default: undefined)
+ Define this on MS win (95, nt) platforms to compile in sbrk emulation.
+ LACKS_UNISTD_H (default: undefined if not WIN32)
+ Define this if your system does not have a <unistd.h>.
+ LACKS_SYS_PARAM_H (default: undefined if not WIN32)
+ Define this if your system does not have a <sys/param.h>.
+ MORECORE (default: sbrk)
+ The name of the routine to call to obtain more memory from the system.
+ MORECORE_FAILURE (default: -1)
+ The value returned upon failure of MORECORE.
+ MORECORE_CLEARS (default 1)
+ true (1) if the routine mapped to MORECORE zeroes out memory (which
+ holds for sbrk).
+ DEFAULT_TRIM_THRESHOLD
+ DEFAULT_TOP_PAD
+ DEFAULT_MMAP_THRESHOLD
+ DEFAULT_MMAP_MAX
+ Default values of tunable parameters (described in detail below)
+ controlling interaction with host system routines (sbrk, mmap, etc).
+ These values may also be changed dynamically via mallopt(). The
+ preset defaults are those that give best performance for typical
+ programs/systems.
+ USE_DL_PREFIX (default: undefined)
+ Prefix all public routines with the string 'dl'. Useful to
+ quickly avoid procedure declaration conflicts and linker symbol
+ conflicts with existing memory allocation routines.
+
+
+*/
+
+\f
+#ifndef __MALLOC_H__
+#define __MALLOC_H__
+
+/* Preliminaries */
+
+#ifndef __STD_C
+#ifdef __STDC__
+#define __STD_C 1
+#else
+#if __cplusplus
+#define __STD_C 1
+#else
+#define __STD_C 0
+#endif /*__cplusplus*/
+#endif /*__STDC__*/
+#endif /*__STD_C*/
+
+#ifndef Void_t
+#if (__STD_C || defined(WIN32))
+#define Void_t void
+#else
+#define Void_t char
+#endif
+#endif /*Void_t*/
+
+#if __STD_C
+#include <linux/stddef.h> /* for size_t */
+#else
+#include <sys/types.h>
+#endif /* __STD_C */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#if 0 /* not for U-Boot */
+#include <stdio.h> /* needed for malloc_stats */
+#endif
+
+
+/*
+ Compile-time options
+*/
+
+
+/*
+ Debugging:
+
+ Because freed chunks may be overwritten with link fields, this
+ malloc will often die when freed memory is overwritten by user
+ programs. This can be very effective (albeit in an annoying way)
+ in helping track down dangling pointers.
+
+ If you compile with -DDEBUG, a number of assertion checks are
+ enabled that will catch more memory errors. You probably won't be
+ able to make much sense of the actual assertion errors, but they
+ should help you locate incorrectly overwritten memory. The
+ checking is fairly extensive, and will slow down execution
+ noticeably. Calling malloc_stats or mallinfo with DEBUG set will
+ attempt to check every non-mmapped allocated and free chunk in the
+ course of computing the summmaries. (By nature, mmapped regions
+ cannot be checked very much automatically.)
+
+ Setting DEBUG may also be helpful if you are trying to modify
+ this code. The assertions in the check routines spell out in more
+ detail the assumptions and invariants underlying the algorithms.
+
+*/
+
+/*
+ INTERNAL_SIZE_T is the word-size used for internal bookkeeping
+ of chunk sizes. On a 64-bit machine, you can reduce malloc
+ overhead by defining INTERNAL_SIZE_T to be a 32 bit `unsigned int'
+ at the expense of not being able to handle requests greater than
+ 2^31. This limitation is hardly ever a concern; you are encouraged
+ to set this. However, the default version is the same as size_t.
+*/
+
+#ifndef INTERNAL_SIZE_T
+#define INTERNAL_SIZE_T size_t
+#endif
+
+/*
+ REALLOC_ZERO_BYTES_FREES should be set if a call to
+ realloc with zero bytes should be the same as a call to free.
+ Some people think it should. Otherwise, since this malloc
+ returns a unique pointer for malloc(0), so does realloc(p, 0).
+*/
+
+
+/* #define REALLOC_ZERO_BYTES_FREES */
+
+
+/*
+ WIN32 causes an emulation of sbrk to be compiled in
+ mmap-based options are not currently supported in WIN32.
+*/
+
+/* #define WIN32 */
+#ifdef WIN32
+#define MORECORE wsbrk
+#define HAVE_MMAP 0
+
+#define LACKS_UNISTD_H
+#define LACKS_SYS_PARAM_H
+
+/*
+ Include 'windows.h' to get the necessary declarations for the
+ Microsoft Visual C++ data structures and routines used in the 'sbrk'
+ emulation.
+
+ Define WIN32_LEAN_AND_MEAN so that only the essential Microsoft
+ Visual C++ header files are included.
+*/
+#define WIN32_LEAN_AND_MEAN
+#include <windows.h>
+#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 here.
+
+ USE_MEMCPY should be defined as 1 if you actually want to
+ have memset and memcpy called. People report that the macro
+ versions are often enough faster than libc versions on many
+ systems that it is better to use them.
+
+*/
+
+#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))
+
+#if __STD_C
+void* memset(void*, int, size_t);
+void* memcpy(void*, const void*, size_t);
+#else
+#ifdef WIN32
+/* On Win32 platforms, 'memset()' and 'memcpy()' are already declared in */
+/* 'windows.h' */
+#else
+Void_t* memset();
+Void_t* memcpy();
+#endif
+#endif
+#endif
+
+#if USE_MEMCPY
+
+/* The following macros are only invoked with (2n+1)-multiples of
+ INTERNAL_SIZE_T units, with a positive integer n. This is exploited
+ for fast inline execution when n is small. */
+
+#define MALLOC_ZERO(charp, nbytes) \
+do { \
+ INTERNAL_SIZE_T mzsz = (nbytes); \
+ if(mzsz <= 9*sizeof(mzsz)) { \
+ INTERNAL_SIZE_T* mz = (INTERNAL_SIZE_T*) (charp); \
+ if(mzsz >= 5*sizeof(mzsz)) { *mz++ = 0; \
+ *mz++ = 0; \
+ if(mzsz >= 7*sizeof(mzsz)) { *mz++ = 0; \
+ *mz++ = 0; \
+ if(mzsz >= 9*sizeof(mzsz)) { *mz++ = 0; \
+ *mz++ = 0; }}} \
+ *mz++ = 0; \
+ *mz++ = 0; \
+ *mz = 0; \
+ } else memset((charp), 0, mzsz); \
+} while(0)
+
+#define MALLOC_COPY(dest,src,nbytes) \
+do { \
+ INTERNAL_SIZE_T mcsz = (nbytes); \
+ if(mcsz <= 9*sizeof(mcsz)) { \
+ INTERNAL_SIZE_T* mcsrc = (INTERNAL_SIZE_T*) (src); \
+ INTERNAL_SIZE_T* mcdst = (INTERNAL_SIZE_T*) (dest); \
+ if(mcsz >= 5*sizeof(mcsz)) { *mcdst++ = *mcsrc++; \
+ *mcdst++ = *mcsrc++; \
+ if(mcsz >= 7*sizeof(mcsz)) { *mcdst++ = *mcsrc++; \
+ *mcdst++ = *mcsrc++; \
+ if(mcsz >= 9*sizeof(mcsz)) { *mcdst++ = *mcsrc++; \
+ *mcdst++ = *mcsrc++; }}} \
+ *mcdst++ = *mcsrc++; \
+ *mcdst++ = *mcsrc++; \
+ *mcdst = *mcsrc ; \
+ } else memcpy(dest, src, mcsz); \
+} while(0)
+
+#else /* !USE_MEMCPY */
+
+/* Use Duff's device for good zeroing/copying performance. */
+
+#define MALLOC_ZERO(charp, nbytes) \
+do { \
+ INTERNAL_SIZE_T* mzp = (INTERNAL_SIZE_T*)(charp); \
+ long mctmp = (nbytes)/sizeof(INTERNAL_SIZE_T), mcn; \
+ if (mctmp < 8) mcn = 0; else { mcn = (mctmp-1)/8; mctmp %= 8; } \
+ switch (mctmp) { \
+ case 0: for(;;) { *mzp++ = 0; \
+ case 7: *mzp++ = 0; \
+ case 6: *mzp++ = 0; \
+ case 5: *mzp++ = 0; \
+ case 4: *mzp++ = 0; \
+ case 3: *mzp++ = 0; \
+ case 2: *mzp++ = 0; \
+ case 1: *mzp++ = 0; if(mcn <= 0) break; mcn--; } \
+ } \
+} while(0)
+
+#define MALLOC_COPY(dest,src,nbytes) \
+do { \
+ INTERNAL_SIZE_T* mcsrc = (INTERNAL_SIZE_T*) src; \
+ INTERNAL_SIZE_T* mcdst = (INTERNAL_SIZE_T*) dest; \
+ long mctmp = (nbytes)/sizeof(INTERNAL_SIZE_T), mcn; \
+ if (mctmp < 8) mcn = 0; else { mcn = (mctmp-1)/8; mctmp %= 8; } \
+ switch (mctmp) { \
+ case 0: for(;;) { *mcdst++ = *mcsrc++; \
+ case 7: *mcdst++ = *mcsrc++; \
+ case 6: *mcdst++ = *mcsrc++; \
+ case 5: *mcdst++ = *mcsrc++; \
+ case 4: *mcdst++ = *mcsrc++; \
+ case 3: *mcdst++ = *mcsrc++; \
+ case 2: *mcdst++ = *mcsrc++; \
+ case 1: *mcdst++ = *mcsrc++; if(mcn <= 0) break; mcn--; } \
+ } \
+} while(0)
+
+#endif
+
+
+/*
+ Define HAVE_MMAP to optionally make malloc() use mmap() to
+ allocate very large blocks. These will be returned to the
+ operating system immediately after a free().
+*/
+
+/***
+#ifndef HAVE_MMAP
+#define HAVE_MMAP 1
+#endif
+***/
+#undef HAVE_MMAP /* Not available for U-Boot */
+
+/*
+ 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 INTERNAL_LINUX_C_LIB
+#define HAVE_MREMAP 1
+#else
+#define HAVE_MREMAP 0
+#endif
+#endif
+***/
+#undef HAVE_MREMAP /* Not available for U-Boot */
+
+#ifdef HAVE_MMAP
+
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/mman.h>
+
+#if !defined(MAP_ANONYMOUS) && defined(MAP_ANON)
+#define MAP_ANONYMOUS MAP_ANON
+#endif
+
+#endif /* HAVE_MMAP */
+
+/*
+ Access to system page size. To the extent possible, this malloc
+ manages memory from the system in page-size units.
+
+ The following mechanics for getpagesize were adapted from
+ bsd/gnu getpagesize.h
+*/
+
+#define LACKS_UNISTD_H /* Shortcut for U-Boot */
+#define malloc_getpagesize 4096
+
+#ifndef LACKS_UNISTD_H
+# include <unistd.h>
+#endif
+
+#ifndef malloc_getpagesize
+# ifdef _SC_PAGESIZE /* some SVR4 systems omit an underscore */
+# ifndef _SC_PAGE_SIZE
+# define _SC_PAGE_SIZE _SC_PAGESIZE
+# endif
+# endif
+# ifdef _SC_PAGE_SIZE
+# define malloc_getpagesize sysconf(_SC_PAGE_SIZE)
+# else
+# if defined(BSD) || defined(DGUX) || defined(HAVE_GETPAGESIZE)
+ extern size_t getpagesize();
+# define malloc_getpagesize getpagesize()
+# else
+# ifdef WIN32
+# define malloc_getpagesize (4096) /* TBD: Use 'GetSystemInfo' instead */
+# else
+# ifndef LACKS_SYS_PARAM_H
+# include <sys/param.h>
+# endif
+# ifdef EXEC_PAGESIZE
+# define malloc_getpagesize EXEC_PAGESIZE
+# else
+# ifdef NBPG
+# ifndef CLSIZE
+# define malloc_getpagesize NBPG
+# else
+# define malloc_getpagesize (NBPG * CLSIZE)
+# endif
+# else
+# ifdef NBPC
+# define malloc_getpagesize NBPC
+# else
+# ifdef PAGESIZE
+# define malloc_getpagesize PAGESIZE
+# else
+# define malloc_getpagesize (4096) /* just guess */
+# endif
+# endif
+# endif
+# endif
+# endif
+# endif
+# endif
+#endif
+
+
+/*
+
+ This version of malloc supports the standard SVID/XPG mallinfo
+ routine that returns a struct containing the same kind of
+ information you can get from malloc_stats. It should work on
+ any SVID/XPG compliant system that has a /usr/include/malloc.h
+ defining struct mallinfo. (If you'd like to install such a thing
+ yourself, cut out the preliminary declarations as described above
+ and below and save them in a malloc.h file. But there's no
+ compelling reason to bother to do this.)
+
+ The main declaration needed is the mallinfo struct that is returned
+ (by-copy) by mallinfo(). The SVID/XPG malloinfo struct contains a
+ bunch of fields, most of which are not even meaningful in this
+ version of malloc. Some of these fields are are instead filled by
+ mallinfo() with other numbers that might possibly be of interest.
+
+ HAVE_USR_INCLUDE_MALLOC_H should be set if you have a
+ /usr/include/malloc.h file that includes a declaration of struct
+ mallinfo. If so, it is included; else an SVID2/XPG2 compliant
+ version is declared below. These must be precisely the same for
+ mallinfo() to work.
+
+*/
+
+/* #define HAVE_USR_INCLUDE_MALLOC_H */
+
+#ifdef HAVE_USR_INCLUDE_MALLOC_H
+#include "/usr/include/malloc.h"
+#else
+
+/* SVID2/XPG mallinfo structure */
+
+struct mallinfo {
+ int arena; /* total space allocated from system */
+ int ordblks; /* number of non-inuse chunks */
+ int smblks; /* unused -- always zero */
+ int hblks; /* number of mmapped regions */
+ int hblkhd; /* total space in mmapped regions */
+ int usmblks; /* unused -- always zero */
+ int fsmblks; /* unused -- always zero */
+ int uordblks; /* total allocated space */
+ int fordblks; /* total non-inuse space */
+ int keepcost; /* top-most, releasable (via malloc_trim) space */
+};
+
+/* SVID2/XPG mallopt options */
+
+#define M_MXFAST 1 /* UNUSED in this malloc */
+#define M_NLBLKS 2 /* UNUSED in this malloc */
+#define M_GRAIN 3 /* UNUSED in this malloc */
+#define M_KEEP 4 /* UNUSED in this malloc */
+
+#endif
+
+/* mallopt options that actually do something */
+
+#define M_TRIM_THRESHOLD -1
+#define M_TOP_PAD -2
+#define M_MMAP_THRESHOLD -3
+#define M_MMAP_MAX -4
+
+
+#ifndef DEFAULT_TRIM_THRESHOLD
+#define DEFAULT_TRIM_THRESHOLD (128 * 1024)
+#endif
+
+/*
+ M_TRIM_THRESHOLD is the maximum amount of unused top-most memory
+ to keep before releasing via malloc_trim in free().
+
+ Automatic trimming is mainly useful in long-lived programs.
+ Because trimming via sbrk can be slow on some systems, and can
+ sometimes be wasteful (in cases where programs immediately
+ afterward allocate more large chunks) the value should be high
+ enough so that your overall system performance would improve by
+ releasing.
+
+ The trim threshold and the mmap control parameters (see below)
+ can be traded off with one another. Trimming and mmapping are
+ two different ways of releasing unused memory back to the
+ system. Between these two, it is often possible to keep
+ system-level demands of a long-lived program down to a bare
+ minimum. For example, in one test suite of sessions measuring
+ the XF86 X server on Linux, using a trim threshold of 128K and a
+ mmap threshold of 192K led to near-minimal long term resource
+ consumption.
+
+ If you are using this malloc in a long-lived program, it should
+ pay to experiment with these values. As a rough guide, you
+ might set to a value close to the average size of a process
+ (program) running on your system. Releasing this much memory
+ would allow such a process to run in memory. Generally, it's
+ worth it to tune for trimming rather tham memory mapping when a
+ program undergoes phases where several large chunks are
+ allocated and released in ways that can reuse each other's
+ storage, perhaps mixed with phases where there are no such
+ chunks at all. And in well-behaved long-lived programs,
+ controlling release of large blocks via trimming versus mapping
+ is usually faster.
+
+ However, in most programs, these parameters serve mainly as
+ protection against the system-level effects of carrying around
+ massive amounts of unneeded memory. Since frequent calls to
+ sbrk, mmap, and munmap otherwise degrade performance, the default
+ parameters are set to relatively high values that serve only as
+ safeguards.
+
+ The default trim value is high enough to cause trimming only in
+ fairly extreme (by current memory consumption standards) cases.
+ It must be greater than page size to have any useful effect. To
+ disable trimming completely, you can set to (unsigned long)(-1);
+
+
+*/
+
+
+#ifndef DEFAULT_TOP_PAD
+#define DEFAULT_TOP_PAD (0)
+#endif
+
+/*
+ M_TOP_PAD is the amount of extra `padding' space to allocate or
+ retain whenever sbrk is called. It is used in two ways internally:
+
+ * When sbrk is called to extend the top of the arena to satisfy
+ a new malloc request, this much padding is added to the sbrk
+ request.
+
+ * When malloc_trim is called automatically from free(),
+ it is used as the `pad' argument.
+
+ In both cases, the actual amount of padding is rounded
+ so that the end of the arena is always a system page boundary.
+
+ The main reason for using padding is to avoid calling sbrk so
+ often. Having even a small pad greatly reduces the likelihood
+ that nearly every malloc request during program start-up (or
+ after trimming) will invoke sbrk, which needlessly wastes
+ time.
+
+ Automatic rounding-up to page-size units is normally sufficient
+ to avoid measurable overhead, so the default is 0. However, in
+ systems where sbrk is relatively slow, it can pay to increase
+ this value, at the expense of carrying around more memory than
+ the program needs.
+
+*/
+
+
+#ifndef DEFAULT_MMAP_THRESHOLD
+#define DEFAULT_MMAP_THRESHOLD (128 * 1024)
+#endif
+
+/*
+
+ M_MMAP_THRESHOLD is the request size threshold for using mmap()
+ to service a request. Requests of at least this size that cannot
+ be allocated using already-existing space will be serviced via mmap.
+ (If enough normal freed space already exists it is used instead.)
+
+ Using mmap segregates relatively large chunks of memory so that
+ they can be individually obtained and released from the host
+ system. A request serviced through mmap is never reused by any
+ other request (at least not directly; the system may just so
+ happen to remap successive requests to the same locations).
+
+ Segregating space in this way has the benefit that mmapped space
+ can ALWAYS be individually released back to the system, which
+ helps keep the system level memory demands of a long-lived
+ program low. Mapped memory can never become `locked' between
+ other chunks, as can happen with normally allocated chunks, which
+ menas that even trimming via malloc_trim would not release them.
+
+ However, it has the disadvantages that:
+
+ 1. The space cannot be reclaimed, consolidated, and then
+ used to service later requests, as happens with normal chunks.
+ 2. It can lead to more wastage because of mmap page alignment
+ requirements
+ 3. It causes malloc performance to be more dependent on host
+ system memory management support routines which may vary in
+ implementation quality and may impose arbitrary
+ limitations. Generally, servicing a request via normal
+ malloc steps is faster than going through a system's mmap.
+
+ All together, these considerations should lead you to use mmap
+ only for relatively large requests.
+
+
+*/
+
+
+#ifndef DEFAULT_MMAP_MAX
+#ifdef HAVE_MMAP
+#define DEFAULT_MMAP_MAX (64)
+#else
+#define DEFAULT_MMAP_MAX (0)
+#endif
+#endif
+
+/*
+ M_MMAP_MAX is the maximum number of requests to simultaneously
+ service using mmap. This parameter exists because:
+
+ 1. Some systems have a limited number of internal tables for
+ use by mmap.
+ 2. In most systems, overreliance on mmap can degrade overall
+ performance.
+ 3. If a program allocates many large regions, it is probably
+ better off using normal sbrk-based allocation routines that
+ can reclaim and reallocate normal heap memory. Using a
+ small value allows transition into this mode after the
+ first few allocations.
+
+ Setting to 0 disables all use of mmap. If HAVE_MMAP is not set,
+ the default value is 0, and attempts to set it to non-zero values
+ in mallopt will fail.
+*/
+
+
+/*
+ USE_DL_PREFIX will prefix all public routines with the string 'dl'.
+ Useful to quickly avoid procedure declaration conflicts and linker
+ symbol conflicts with existing memory allocation routines.
+
+*/
+
+/* #define USE_DL_PREFIX */
+
+
+/*
+
+ Special defines for linux libc
+
+ Except when compiled using these special defines for Linux libc
+ using weak aliases, this malloc is NOT designed to work in
+ multithreaded applications. No semaphores or other concurrency
+ control are provided to ensure that multiple malloc or free calls
+ don't run at the same time, which could be disasterous. A single
+ semaphore could be used across malloc, realloc, and free (which is
+ essentially the effect of the linux weak alias approach). It would
+ be hard to obtain finer granularity.
+
+*/
+
+
+#ifdef INTERNAL_LINUX_C_LIB
+
+#if __STD_C
+
+Void_t * __default_morecore_init (ptrdiff_t);
+Void_t *(*__morecore)(ptrdiff_t) = __default_morecore_init;
+
+#else
+
+Void_t * __default_morecore_init ();
+Void_t *(*__morecore)() = __default_morecore_init;
+
+#endif
+
+#define MORECORE (*__morecore)
+#define MORECORE_FAILURE 0
+#define MORECORE_CLEARS 1
+
+#else /* INTERNAL_LINUX_C_LIB */
+
+#if __STD_C
+extern Void_t* sbrk(ptrdiff_t);
+#else
+extern Void_t* sbrk();
+#endif
+
+#ifndef MORECORE
+#define MORECORE sbrk
+#endif
+
+#ifndef MORECORE_FAILURE
+#define MORECORE_FAILURE -1
+#endif
+
+#ifndef MORECORE_CLEARS
+#define MORECORE_CLEARS 1
+#endif
+
+#endif /* INTERNAL_LINUX_C_LIB */
+
+#if defined(INTERNAL_LINUX_C_LIB) && defined(__ELF__)
+
+#define cALLOc __libc_calloc
+#define fREe __libc_free
+#define mALLOc __libc_malloc
+#define mEMALIGn __libc_memalign
+#define rEALLOc __libc_realloc
+#define vALLOc __libc_valloc
+#define pvALLOc __libc_pvalloc
+#define mALLINFo __libc_mallinfo
+#define mALLOPt __libc_mallopt
+
+#pragma weak calloc = __libc_calloc
+#pragma weak free = __libc_free
+#pragma weak cfree = __libc_free
+#pragma weak malloc = __libc_malloc
+#pragma weak memalign = __libc_memalign
+#pragma weak realloc = __libc_realloc
+#pragma weak valloc = __libc_valloc
+#pragma weak pvalloc = __libc_pvalloc
+#pragma weak mallinfo = __libc_mallinfo
+#pragma weak mallopt = __libc_mallopt
+
+#else
+
+#ifdef USE_DL_PREFIX
+#define cALLOc dlcalloc
+#define fREe dlfree
+#define mALLOc dlmalloc
+#define mEMALIGn dlmemalign
+#define rEALLOc dlrealloc
+#define vALLOc dlvalloc
+#define pvALLOc dlpvalloc
+#define mALLINFo dlmallinfo
+#define mALLOPt dlmallopt
+#else /* USE_DL_PREFIX */
+#define cALLOc calloc
+#define fREe free
+#define mALLOc malloc
+#define mEMALIGn memalign
+#define rEALLOc realloc
+#define vALLOc valloc
+#define pvALLOc pvalloc
+#define mALLINFo mallinfo
+#define mALLOPt mallopt
+#endif /* USE_DL_PREFIX */
+
+#endif
+
+/* Public routines */
+
+#if __STD_C
+
+Void_t* mALLOc(size_t);
+void fREe(Void_t*);
+Void_t* rEALLOc(Void_t*, size_t);
+Void_t* mEMALIGn(size_t, size_t);
+Void_t* vALLOc(size_t);
+Void_t* pvALLOc(size_t);
+Void_t* cALLOc(size_t, size_t);
+void cfree(Void_t*);
+int malloc_trim(size_t);
+size_t malloc_usable_size(Void_t*);
+void malloc_stats(void);
+int mALLOPt(int, int);
+struct mallinfo mALLINFo(void);
+#else
+Void_t* mALLOc();
+void fREe();
+Void_t* rEALLOc();
+Void_t* mEMALIGn();
+Void_t* vALLOc();
+Void_t* pvALLOc();
+Void_t* cALLOc();
+void cfree();
+int malloc_trim();
+size_t malloc_usable_size();
+void malloc_stats();
+int mALLOPt();
+struct mallinfo mALLINFo();
+#endif
+
+/*
+ * Begin and End of memory area for malloc(), and current "brk"
+ */
+extern ulong mem_malloc_start;
+extern ulong mem_malloc_end;
+extern ulong mem_malloc_brk;
+
+void mem_malloc_init(ulong start, ulong size);
+
+#ifdef __cplusplus
+}; /* end of extern "C" */
+#endif
+
+#endif /* __MALLOC_H__ */
Code Review / kvmfornfv.git / blobdiff