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| author | Sascha Hauer <s.hauer@pengutronix.de> | 2011-12-22 23:19:19 +0100 |
|---|---|---|
| committer | Sascha Hauer <s.hauer@pengutronix.de> | 2012-04-30 13:28:36 +0200 |
| commit | 47f8cf2d0875c6dc1107a7559c458eeac08a16dd (patch) | |
| tree | 3246cc92f03dbf25ac04c0c1352dbc46ee52fd8f /common | |
| parent | b2c48771cbb3f017c2972aa6a4c5e1a12cf6d836 (diff) | |
| download | barebox-47f8cf2d0875c6dc1107a7559c458eeac08a16dd.tar.gz barebox-47f8cf2d0875c6dc1107a7559c458eeac08a16dd.tar.xz | |
remove dlmalloc.src
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Diffstat (limited to 'common')
| -rw-r--r-- | common/dlmalloc.src | 3265 |
1 files changed, 0 insertions, 3265 deletions
diff --git a/common/dlmalloc.src b/common/dlmalloc.src deleted file mode 100644 index 32a38bc70c..0000000000 --- a/common/dlmalloc.src +++ /dev/null @@ -1,3265 +0,0 @@ -/* ---------- To make a malloc.h, start cutting here ------------ */ - -/* - 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. - - -*/ - - - - -/* 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 <stddef.h> /* for size_t */ -#else -#include <sys/types.h> -#endif - -#ifdef __cplusplus -extern "C" { -#endif - -#include <stdio.h> /* needed for malloc_stats */ - - -/* - 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. - -*/ - -#if DEBUG -#include <assert.h> -#else -#define assert(x) ((void)0) -#endif - - -/* - 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 - -/* - 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 - -#if 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 -*/ - -#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 */ - -#if 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 -#if 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(); -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 - - -#ifdef __cplusplus -}; /* end of extern "C" */ -#endif - -/* ---------- To make a malloc.h, end cutting here ------------ */ - - -/* - Emulation of sbrk for WIN32 - All code within the ifdef WIN32 is untested by me. - - Thanks to Martin Fong and others for supplying this. -*/ - - -#ifdef WIN32 - -#define AlignPage(add) (((add) + (malloc_getpagesize-1)) & \ -~(malloc_getpagesize-1)) -#define AlignPage64K(add) (((add) + (0x10000 - 1)) & ~(0x10000 - 1)) - -/* resrve 64MB to insure large contiguous space */ -#define RESERVED_SIZE (1024*1024*64) -#define NEXT_SIZE (2048*1024) -#define TOP_MEMORY ((unsigned long)2*1024*1024*1024) - -struct GmListElement; -typedef struct GmListElement GmListElement; - -struct GmListElement -{ - GmListElement* next; - void* base; -}; - -static GmListElement* head = 0; -static unsigned int gNextAddress = 0; -static unsigned int gAddressBase = 0; -static unsigned int gAllocatedSize = 0; - -static -GmListElement* makeGmListElement (void* bas) -{ - GmListElement* this; - this = (GmListElement*)(void*)LocalAlloc (0, sizeof (GmListElement)); - assert (this); - if (this) - { - this->base = bas; - this->next = head; - head = this; - } - return this; -} - -void gcleanup () -{ - BOOL rval; - assert ( (head == NULL) || (head->base == (void*)gAddressBase)); - if (gAddressBase && (gNextAddress - gAddressBase)) - { - rval = VirtualFree ((void*)gAddressBase, - gNextAddress - gAddressBase, - MEM_DECOMMIT); - assert (rval); - } - while (head) - { - GmListElement* next = head->next; - rval = VirtualFree (head->base, 0, MEM_RELEASE); - assert (rval); - LocalFree (head); - head = next; - } -} - -static -void* findRegion (void* start_address, unsigned long size) -{ - MEMORY_BASIC_INFORMATION info; - if (size >= TOP_MEMORY) return NULL; - - while ((unsigned long)start_address + size < TOP_MEMORY) - { - VirtualQuery (start_address, &info, sizeof (info)); - if ((info.State == MEM_FREE) && (info.RegionSize >= size)) - return start_address; - else - { - /* Requested region is not available so see if the */ - /* next region is available. Set 'start_address' */ - /* to the next region and call 'VirtualQuery()' */ - /* again. */ - - start_address = (char*)info.BaseAddress + info.RegionSize; - - /* Make sure we start looking for the next region */ - /* on the *next* 64K boundary. Otherwise, even if */ - /* the new region is free according to */ - /* 'VirtualQuery()', the subsequent call to */ - /* 'VirtualAlloc()' (which follows the call to */ - /* this routine in 'wsbrk()') will round *down* */ - /* the requested address to a 64K boundary which */ - /* we already know is an address in the */ - /* unavailable region. Thus, the subsequent call */ - /* to 'VirtualAlloc()' will fail and bring us back */ - /* here, causing us to go into an infinite loop. */ - - start_address = - (void *) AlignPage64K((unsigned long) start_address); - } - } - return NULL; - -} - - -void* wsbrk (long size) -{ - void* tmp; - if (size > 0) - { - if (gAddressBase == 0) - { - gAllocatedSize = max (RESERVED_SIZE, AlignPage (size)); - gNextAddress = gAddressBase = - (unsigned int)VirtualAlloc (NULL, gAllocatedSize, - MEM_RESERVE, PAGE_NOACCESS); - } else if (AlignPage (gNextAddress + size) > (gAddressBase + -gAllocatedSize)) - { - long new_size = max (NEXT_SIZE, AlignPage (size)); - void* new_address = (void*)(gAddressBase+gAllocatedSize); - do - { - new_address = findRegion (new_address, new_size); - - if (new_address == 0) - return (void*)-1; - - gAddressBase = gNextAddress = - (unsigned int)VirtualAlloc (new_address, new_size, - MEM_RESERVE, PAGE_NOACCESS); - /* repeat in case of race condition */ - /* The region that we found has been snagged */ - /* by another thread */ - } - while (gAddressBase == 0); - - assert (new_address == (void*)gAddressBase); - - gAllocatedSize = new_size; - - if (!makeGmListElement ((void*)gAddressBase)) - return (void*)-1; - } - if ((size + gNextAddress) > AlignPage (gNextAddress)) - { - void* res; - res = VirtualAlloc ((void*)AlignPage (gNextAddress), - (size + gNextAddress - - AlignPage (gNextAddress)), - MEM_COMMIT, PAGE_READWRITE); - if (res == 0) - return (void*)-1; - } - tmp = (void*)gNextAddress; - gNextAddress = (unsigned int)tmp + size; - return tmp; - } - else if (size < 0) - { - unsigned int alignedGoal = AlignPage (gNextAddress + size); - /* Trim by releasing the virtual memory */ - if (alignedGoal >= gAddressBase) - { - VirtualFree ((void*)alignedGoal, gNextAddress - alignedGoal, - MEM_DECOMMIT); - gNextAddress = gNextAddress + size; - return (void*)gNextAddress; - } - else - { - VirtualFree ((void*)gAddressBase, gNextAddress - gAddressBase, - MEM_DECOMMIT); - gNextAddress = gAddressBase; - return (void*)-1; - } - } - else - { - return (void*)gNextAddress; - } -} - -#endif - - - -/* - Type declarations -*/ - - -struct malloc_chunk -{ - INTERNAL_SIZE_T prev_size; /* Size of previous chunk (if free). */ - INTERNAL_SIZE_T size; /* Size in bytes, including overhead. */ - struct malloc_chunk* fd; /* double links -- used only if free. */ - struct malloc_chunk* bk; -}; - -typedef struct malloc_chunk* mchunkptr; - -/* - - malloc_chunk details: - - (The following includes lightly edited explanations by Colin Plumb.) - - Chunks of memory are maintained using a `boundary tag' method as - described in e.g., Knuth or Standish. (See the paper by Paul - Wilson ftp://ftp.cs.utexas.edu/pub/garbage/allocsrv.ps for a - survey of such techniques.) Sizes of free chunks are stored both - in the front of each chunk and at the end. This makes - consolidating fragmented chunks into bigger chunks very fast. The - size fields also hold bits representing whether chunks are free or - in use. - - An allocated chunk looks like this: - - - chunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | Size of previous chunk, if allocated | | - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | Size of chunk, in bytes |P| - mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | User data starts here... . - . . - . (malloc_usable_space() bytes) . - . | -nextchunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | Size of chunk | - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - - - Where "chunk" is the front of the chunk for the purpose of most of - the malloc code, but "mem" is the pointer that is returned to the - user. "Nextchunk" is the beginning of the next contiguous chunk. - - Chunks always begin on even word boundries, so the mem portion - (which is returned to the user) is also on an even word boundary, and - thus double-word aligned. - - Free chunks are stored in circular doubly-linked lists, and look like this: - - chunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | Size of previous chunk | - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - `head:' | Size of chunk, in bytes |P| - mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | Forward pointer to next chunk in list | - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | Back pointer to previous chunk in list | - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | Unused space (may be 0 bytes long) . - . . - . | -nextchunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - `foot:' | Size of chunk, in bytes | - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - - The P (PREV_INUSE) bit, stored in the unused low-order bit of the - chunk size (which is always a multiple of two words), is an in-use - bit for the *previous* chunk. If that bit is *clear*, then the - word before the current chunk size contains the previous chunk - size, and can be used to find the front of the previous chunk. - (The very first chunk allocated always has this bit set, - preventing access to non-existent (or non-owned) memory.) - - Note that the `foot' of the current chunk is actually represented - as the prev_size of the NEXT chunk. (This makes it easier to - deal with alignments etc). - - The two exceptions to all this are - - 1. The special chunk `top', which doesn't bother using the - trailing size field since there is no - next contiguous chunk that would have to index off it. (After - initialization, `top' is forced to always exist. If it would - become less than MINSIZE bytes long, it is replenished via - malloc_extend_top.) - - 2. Chunks allocated via mmap, which have the second-lowest-order - bit (IS_MMAPPED) set in their size fields. Because they are - never merged or traversed from any other chunk, they have no - foot size or inuse information. - - Available chunks are kept in any of several places (all declared below): - - * `av': An array of chunks serving as bin headers for consolidated - chunks. Each bin is doubly linked. The bins are approximately - proportionally (log) spaced. There are a lot of these bins - (128). This may look excessive, but works very well in - practice. All procedures maintain the invariant that no - consolidated chunk physically borders another one. Chunks in - bins are kept in size order, with ties going to the - approximately least recently used chunk. - - The chunks in each bin are maintained in decreasing sorted order by - size. This is irrelevant for the small bins, which all contain - the same-sized chunks, but facilitates best-fit allocation for - larger chunks. (These lists are just sequential. Keeping them in - order almost never requires enough traversal to warrant using - fancier ordered data structures.) Chunks of the same size are - linked with the most recently freed at the front, and allocations - are taken from the back. This results in LRU or FIFO allocation - order, which tends to give each chunk an equal opportunity to be - consolidated with adjacent freed chunks, resulting in larger free - chunks and less fragmentation. - - * `top': The top-most available chunk (i.e., the one bordering the - end of available memory) is treated specially. It is never - included in any bin, is used only if no other chunk is - available, and is released back to the system if it is very - large (see M_TRIM_THRESHOLD). - - * `last_remainder': A bin holding only the remainder of the - most recently split (non-top) chunk. This bin is checked - before other non-fitting chunks, so as to provide better - locality for runs of sequentially allocated chunks. - - * Implicitly, through the host system's memory mapping tables. - If supported, requests greater than a threshold are usually - serviced via calls to mmap, and then later released via munmap. - -*/ - - - - - -/* sizes, alignments */ - -#define SIZE_SZ (sizeof(INTERNAL_SIZE_T)) -#define MALLOC_ALIGNMENT (SIZE_SZ + SIZE_SZ) -#define MALLOC_ALIGN_MASK (MALLOC_ALIGNMENT - 1) -#define MINSIZE (sizeof(struct malloc_chunk)) - -/* conversion from malloc headers to user pointers, and back */ - -#define chunk2mem(p) ((Void_t*)((char*)(p) + 2*SIZE_SZ)) -#define mem2chunk(mem) ((mchunkptr)((char*)(mem) - 2*SIZE_SZ)) - -/* pad request bytes into a usable size */ - -#define request2size(req) \ - (((long)((req) + (SIZE_SZ + MALLOC_ALIGN_MASK)) < \ - (long)(MINSIZE + MALLOC_ALIGN_MASK)) ? MINSIZE : \ - (((req) + (SIZE_SZ + MALLOC_ALIGN_MASK)) & ~(MALLOC_ALIGN_MASK))) - -/* Check if m has acceptable alignment */ - -#define aligned_OK(m) (((unsigned long)((m)) & (MALLOC_ALIGN_MASK)) == 0) - - - - -/* - Physical chunk operations -*/ - - -/* size field is or'ed with PREV_INUSE when previous adjacent chunk in use */ - -#define PREV_INUSE 0x1 - -/* size field is or'ed with IS_MMAPPED if the chunk was obtained with mmap() */ - -#define IS_MMAPPED 0x2 - -/* Bits to mask off when extracting size */ - -#define SIZE_BITS (PREV_INUSE|IS_MMAPPED) - - -/* Ptr to next physical malloc_chunk. */ - -#define next_chunk(p) ((mchunkptr)( ((char*)(p)) + ((p)->size & ~PREV_INUSE) )) - -/* Ptr to previous physical malloc_chunk */ - -#define prev_chunk(p)\ - ((mchunkptr)( ((char*)(p)) - ((p)->prev_size) )) - - -/* Treat space at ptr + offset as a chunk */ - -#define chunk_at_offset(p, s) ((mchunkptr)(((char*)(p)) + (s))) - - - - -/* - Dealing with use bits -*/ - -/* extract p's inuse bit */ - -#define inuse(p)\ -((((mchunkptr)(((char*)(p))+((p)->size & ~PREV_INUSE)))->size) & PREV_INUSE) - -/* extract inuse bit of previous chunk */ - -#define prev_inuse(p) ((p)->size & PREV_INUSE) - -/* check for mmap()'ed chunk */ - -#define chunk_is_mmapped(p) ((p)->size & IS_MMAPPED) - -/* set/clear chunk as in use without otherwise disturbing */ - -#define set_inuse(p)\ -((mchunkptr)(((char*)(p)) + ((p)->size & ~PREV_INUSE)))->size |= PREV_INUSE - -#define clear_inuse(p)\ -((mchunkptr)(((char*)(p)) + ((p)->size & ~PREV_INUSE)))->size &= ~(PREV_INUSE) - -/* check/set/clear inuse bits in known places */ - -#define inuse_bit_at_offset(p, s)\ - (((mchunkptr)(((char*)(p)) + (s)))->size & PREV_INUSE) - -#define set_inuse_bit_at_offset(p, s)\ - (((mchunkptr)(((char*)(p)) + (s)))->size |= PREV_INUSE) - -#define clear_inuse_bit_at_offset(p, s)\ - (((mchunkptr)(((char*)(p)) + (s)))->size &= ~(PREV_INUSE)) - - - - -/* - Dealing with size fields -*/ - -/* Get size, ignoring use bits */ - -#define chunksize(p) ((p)->size & ~(SIZE_BITS)) - -/* Set size at head, without disturbing its use bit */ - -#define set_head_size(p, s) ((p)->size = (((p)->size & PREV_INUSE) | (s))) - -/* Set size/use ignoring previous bits in header */ - -#define set_head(p, s) ((p)->size = (s)) - -/* Set size at footer (only when chunk is not in use) */ - -#define set_foot(p, s) (((mchunkptr)((char*)(p) + (s)))->prev_size = (s)) - - - - - -/* - Bins - - The bins, `av_' are an array of pairs of pointers serving as the - heads of (initially empty) doubly-linked lists of chunks, laid out - in a way so that each pair can be treated as if it were in a - malloc_chunk. (This way, the fd/bk offsets for linking bin heads - and chunks are the same). - - Bins for sizes < 512 bytes contain chunks of all the same size, spaced - 8 bytes apart. Larger bins are approximately logarithmically - spaced. (See the table below.) The `av_' array is never mentioned - directly in the code, but instead via bin access macros. - - Bin layout: - - 64 bins of size 8 - 32 bins of size 64 - 16 bins of size 512 - 8 bins of size 4096 - 4 bins of size 32768 - 2 bins of size 262144 - 1 bin of size what's left - - There is actually a little bit of slop in the numbers in bin_index - for the sake of speed. This makes no difference elsewhere. - - The special chunks `top' and `last_remainder' get their own bins, - (this is implemented via yet more trickery with the av_ array), - although `top' is never properly linked to its bin since it is - always handled specially. - -*/ - -#define NAV 128 /* number of bins */ - -typedef struct malloc_chunk* mbinptr; - -/* access macros */ - -#define bin_at(i) ((mbinptr)((char*)&(av_[2*(i) + 2]) - 2*SIZE_SZ)) -#define next_bin(b) ((mbinptr)((char*)(b) + 2 * sizeof(mbinptr))) -#define prev_bin(b) ((mbinptr)((char*)(b) - 2 * sizeof(mbinptr))) - -/* - The first 2 bins are never indexed. The corresponding av_ cells are instead - used for bookkeeping. This is not to save space, but to simplify - indexing, maintain locality, and avoid some initialization tests. -*/ - -#define top (bin_at(0)->fd) /* The topmost chunk */ -#define last_remainder (bin_at(1)) /* remainder from last split */ - - -/* - Because top initially points to its own bin with initial - zero size, thus forcing extension on the first malloc request, - we avoid having any special code in malloc to check whether - it even exists yet. But we still need to in malloc_extend_top. -*/ - -#define initial_top ((mchunkptr)(bin_at(0))) - -/* Helper macro to initialize bins */ - -#define IAV(i) bin_at(i), bin_at(i) - -static mbinptr av_[NAV * 2 + 2] = { - 0, 0, - IAV(0), IAV(1), IAV(2), IAV(3), IAV(4), IAV(5), IAV(6), IAV(7), - IAV(8), IAV(9), IAV(10), IAV(11), IAV(12), IAV(13), IAV(14), IAV(15), - IAV(16), IAV(17), IAV(18), IAV(19), IAV(20), IAV(21), IAV(22), IAV(23), - IAV(24), IAV(25), IAV(26), IAV(27), IAV(28), IAV(29), IAV(30), IAV(31), - IAV(32), IAV(33), IAV(34), IAV(35), IAV(36), IAV(37), IAV(38), IAV(39), - IAV(40), IAV(41), IAV(42), IAV(43), IAV(44), IAV(45), IAV(46), IAV(47), - IAV(48), IAV(49), IAV(50), IAV(51), IAV(52), IAV(53), IAV(54), IAV(55), - IAV(56), IAV(57), IAV(58), IAV(59), IAV(60), IAV(61), IAV(62), IAV(63), - IAV(64), IAV(65), IAV(66), IAV(67), IAV(68), IAV(69), IAV(70), IAV(71), - IAV(72), IAV(73), IAV(74), IAV(75), IAV(76), IAV(77), IAV(78), IAV(79), - IAV(80), IAV(81), IAV(82), IAV(83), IAV(84), IAV(85), IAV(86), IAV(87), - IAV(88), IAV(89), IAV(90), IAV(91), IAV(92), IAV(93), IAV(94), IAV(95), - IAV(96), IAV(97), IAV(98), IAV(99), IAV(100), IAV(101), IAV(102), IAV(103), - IAV(104), IAV(105), IAV(106), IAV(107), IAV(108), IAV(109), IAV(110), IAV(111), - IAV(112), IAV(113), IAV(114), IAV(115), IAV(116), IAV(117), IAV(118), IAV(119), - IAV(120), IAV(121), IAV(122), IAV(123), IAV(124), IAV(125), IAV(126), IAV(127) -}; - - - -/* field-extraction macros */ - -#define first(b) ((b)->fd) -#define last(b) ((b)->bk) - -/* - Indexing into bins -*/ - -#define bin_index(sz) \ -(((((unsigned long)(sz)) >> 9) == 0) ? (((unsigned long)(sz)) >> 3): \ - ((((unsigned long)(sz)) >> 9) <= 4) ? 56 + (((unsigned long)(sz)) >> 6): \ - ((((unsigned long)(sz)) >> 9) <= 20) ? 91 + (((unsigned long)(sz)) >> 9): \ - ((((unsigned long)(sz)) >> 9) <= 84) ? 110 + (((unsigned long)(sz)) >> 12): \ - ((((unsigned long)(sz)) >> 9) <= 340) ? 119 + (((unsigned long)(sz)) >> 15): \ - ((((unsigned long)(sz)) >> 9) <= 1364) ? 124 + (((unsigned long)(sz)) >> 18): \ - 126) -/* - bins for chunks < 512 are all spaced 8 bytes apart, and hold - identically sized chunks. This is exploited in malloc. -*/ - -#define MAX_SMALLBIN 63 -#define MAX_SMALLBIN_SIZE 512 -#define SMALLBIN_WIDTH 8 - -#define smallbin_index(sz) (((unsigned long)(sz)) >> 3) - -/* - Requests are `small' if both the corresponding and the next bin are small -*/ - -#define is_small_request(nb) (nb < MAX_SMALLBIN_SIZE - SMALLBIN_WIDTH) - - - -/* - To help compensate for the large number of bins, a one-level index - structure is used for bin-by-bin searching. `binblocks' is a - one-word bitvector recording whether groups of BINBLOCKWIDTH bins - have any (possibly) non-empty bins, so they can be skipped over - all at once during during traversals. The bits are NOT always - cleared as soon as all bins in a block are empty, but instead only - when all are noticed to be empty during traversal in malloc. -*/ - -#define BINBLOCKWIDTH 4 /* bins per block */ - -#define binblocks (bin_at(0)->size) /* bitvector of nonempty blocks */ - -/* bin<->block macros */ - -#define idx2binblock(ix) ((unsigned)1 << (ix / BINBLOCKWIDTH)) -#define mark_binblock(ii) (binblocks |= idx2binblock(ii)) -#define clear_binblock(ii) (binblocks &= ~(idx2binblock(ii))) - - - - - -/* Other static bookkeeping data */ - -/* variables holding tunable values */ - -static unsigned long trim_threshold = DEFAULT_TRIM_THRESHOLD; -static unsigned long top_pad = DEFAULT_TOP_PAD; -static unsigned int n_mmaps_max = DEFAULT_MMAP_MAX; -static unsigned long mmap_threshold = DEFAULT_MMAP_THRESHOLD; - -/* The first value returned from sbrk */ -static char* sbrk_base = (char*)(-1); - -/* The maximum memory obtained from system via sbrk */ -static unsigned long max_sbrked_mem = 0; - -/* The maximum via either sbrk or mmap */ -static unsigned long max_total_mem = 0; - -/* internal working copy of mallinfo */ -static struct mallinfo current_mallinfo = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }; - -/* The total memory obtained from system via sbrk */ -#define sbrked_mem (current_mallinfo.arena) - -/* Tracking mmaps */ - -static unsigned int n_mmaps = 0; -static unsigned int max_n_mmaps = 0; -static unsigned long mmapped_mem = 0; -static unsigned long max_mmapped_mem = 0; - - - -/* - Debugging support -*/ - -#if DEBUG - - -/* - These routines make a number of assertions about the states - of data structures that should be true at all times. If any - are not true, it's very likely that a user program has somehow - trashed memory. (It's also possible that there is a coding error - in malloc. In which case, please report it!) -*/ - -#if __STD_C -static void do_check_chunk(mchunkptr p) -#else -static void do_check_chunk(p) mchunkptr p; -#endif -{ - INTERNAL_SIZE_T sz = p->size & ~PREV_INUSE; - - /* No checkable chunk is mmapped */ - assert(!chunk_is_mmapped(p)); - - /* Check for legal address ... */ - assert((char*)p >= sbrk_base); - if (p != top) - assert((char*)p + sz <= (char*)top); - else - assert((char*)p + sz <= sbrk_base + sbrked_mem); - -} - - -#if __STD_C -static void do_check_free_chunk(mchunkptr p) -#else -static void do_check_free_chunk(p) mchunkptr p; -#endif -{ - INTERNAL_SIZE_T sz = p->size & ~PREV_INUSE; - mchunkptr next = chunk_at_offset(p, sz); - - do_check_chunk(p); - - /* Check whether it claims to be free ... */ - assert(!inuse(p)); - - /* Unless a special marker, must have OK fields */ - if ((long)sz >= (long)MINSIZE) - { - assert((sz & MALLOC_ALIGN_MASK) == 0); - assert(aligned_OK(chunk2mem(p))); - /* ... matching footer field */ - assert(next->prev_size == sz); - /* ... and is fully consolidated */ - assert(prev_inuse(p)); - assert (next == top || inuse(next)); - - /* ... and has minimally sane links */ - assert(p->fd->bk == p); - assert(p->bk->fd == p); - } - else /* markers are always of size SIZE_SZ */ - assert(sz == SIZE_SZ); -} - -#if __STD_C -static void do_check_inuse_chunk(mchunkptr p) -#else -static void do_check_inuse_chunk(p) mchunkptr p; -#endif -{ - mchunkptr next = next_chunk(p); - do_check_chunk(p); - - /* Check whether it claims to be in use ... */ - assert(inuse(p)); - - /* ... and is surrounded by OK chunks. - Since more things can be checked with free chunks than inuse ones, - if an inuse chunk borders them and debug is on, it's worth doing them. - */ - if (!prev_inuse(p)) - { - mchunkptr prv = prev_chunk(p); - assert(next_chunk(prv) == p); - do_check_free_chunk(prv); - } - if (next == top) - { - assert(prev_inuse(next)); - assert(chunksize(next) >= MINSIZE); - } - else if (!inuse(next)) - do_check_free_chunk(next); - -} - -#if __STD_C -static void do_check_malloced_chunk(mchunkptr p, INTERNAL_SIZE_T s) -#else -static void do_check_malloced_chunk(p, s) mchunkptr p; INTERNAL_SIZE_T s; -#endif -{ - INTERNAL_SIZE_T sz = p->size & ~PREV_INUSE; - long room = sz - s; - - do_check_inuse_chunk(p); - - /* Legal size ... */ - assert((long)sz >= (long)MINSIZE); - assert((sz & MALLOC_ALIGN_MASK) == 0); - assert(room >= 0); - assert(room < (long)MINSIZE); - - /* ... and alignment */ - assert(aligned_OK(chunk2mem(p))); - - - /* ... and was allocated at front of an available chunk */ - assert(prev_inuse(p)); - -} - - -#define check_free_chunk(P) do_check_free_chunk(P) -#define check_inuse_chunk(P) do_check_inuse_chunk(P) -#define check_chunk(P) do_check_chunk(P) -#define check_malloced_chunk(P,N) do_check_malloced_chunk(P,N) -#else -#define check_free_chunk(P) -#define check_inuse_chunk(P) -#define check_chunk(P) -#define check_malloced_chunk(P,N) -#endif - - - -/* - Macro-based internal utilities -*/ - - -/* - Linking chunks in bin lists. - Call these only with variables, not arbitrary expressions, as arguments. -*/ - -/* - Place chunk p of size s in its bin, in size order, - putting it ahead of others of same size. -*/ - - -#define frontlink(P, S, IDX, BK, FD) \ -{ \ - if (S < MAX_SMALLBIN_SIZE) \ - { \ - IDX = smallbin_index(S); \ - mark_binblock(IDX); \ - BK = bin_at(IDX); \ - FD = BK->fd; \ - P->bk = BK; \ - P->fd = FD; \ - FD->bk = BK->fd = P; \ - } \ - else \ - { \ - IDX = bin_index(S); \ - BK = bin_at(IDX); \ - FD = BK->fd; \ - if (FD == BK) mark_binblock(IDX); \ - else \ - { \ - while (FD != BK && S < chunksize(FD)) FD = FD->fd; \ - BK = FD->bk; \ - } \ - P->bk = BK; \ - P->fd = FD; \ - FD->bk = BK->fd = P; \ - } \ -} - - -/* take a chunk off a list */ - -#define unlink(P, BK, FD) \ -{ \ - BK = P->bk; \ - FD = P->fd; \ - FD->bk = BK; \ - BK->fd = FD; \ -} \ - -/* Place p as the last remainder */ - -#define link_last_remainder(P) \ -{ \ - last_remainder->fd = last_remainder->bk = P; \ - P->fd = P->bk = last_remainder; \ -} - -/* Clear the last_remainder bin */ - -#define clear_last_remainder \ - (last_remainder->fd = last_remainder->bk = last_remainder) - - - - - -/* Routines dealing with mmap(). */ - -#if HAVE_MMAP - -#if __STD_C -static mchunkptr mmap_chunk(size_t size) -#else -static mchunkptr mmap_chunk(size) size_t size; -#endif -{ - size_t page_mask = malloc_getpagesize - 1; - mchunkptr p; - -#ifndef MAP_ANONYMOUS - static int fd = -1; -#endif - - if(n_mmaps >= n_mmaps_max) return 0; /* too many regions */ - - /* For mmapped chunks, the overhead is one SIZE_SZ unit larger, because - * there is no following chunk whose prev_size field could be used. - */ - size = (size + SIZE_SZ + page_mask) & ~page_mask; - -#ifdef MAP_ANONYMOUS - p = (mchunkptr)mmap(0, size, PROT_READ|PROT_WRITE, - MAP_PRIVATE|MAP_ANONYMOUS, -1, 0); -#else /* !MAP_ANONYMOUS */ - if (fd < 0) - { - fd = open("/dev/zero", O_RDWR); - if(fd < 0) return 0; - } - p = (mchunkptr)mmap(0, size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0); -#endif - - if(p == (mchunkptr)-1) return 0; - - n_mmaps++; - if (n_mmaps > max_n_mmaps) max_n_mmaps = n_mmaps; - - /* We demand that eight bytes into a page must be 8-byte aligned. */ - assert(aligned_OK(chunk2mem(p))); - - /* The offset to the start of the mmapped region is stored - * in the prev_size field of the chunk; normally it is zero, - * but that can be changed in memalign(). - */ - p->prev_size = 0; - set_head(p, size|IS_MMAPPED); - - mmapped_mem += size; - if ((unsigned long)mmapped_mem > (unsigned long)max_mmapped_mem) - max_mmapped_mem = mmapped_mem; - if ((unsigned long)(mmapped_mem + sbrked_mem) > (unsigned long)max_total_mem) - max_total_mem = mmapped_mem + sbrked_mem; - return p; -} - -#if __STD_C -static void munmap_chunk(mchunkptr p) -#else -static void munmap_chunk(p) mchunkptr p; -#endif -{ - INTERNAL_SIZE_T size = chunksize(p); - int ret; - - assert (chunk_is_mmapped(p)); - assert(! ((char*)p >= sbrk_base && (char*)p < sbrk_base + sbrked_mem)); - assert((n_mmaps > 0)); - assert(((p->prev_size + size) & (malloc_getpagesize-1)) == 0); - - n_mmaps--; - mmapped_mem -= (size + p->prev_size); - - ret = munmap((char *)p - p->prev_size, size + p->prev_size); - - /* munmap returns non-zero on failure */ - assert(ret == 0); -} - -#if HAVE_MREMAP - -#if __STD_C -static mchunkptr mremap_chunk(mchunkptr p, size_t new_size) -#else -static mchunkptr mremap_chunk(p, new_size) mchunkptr p; size_t new_size; -#endif -{ - size_t page_mask = malloc_getpagesize - 1; - INTERNAL_SIZE_T offset = p->prev_size; - INTERNAL_SIZE_T size = chunksize(p); - char *cp; - - assert (chunk_is_mmapped(p)); - assert(! ((char*)p >= sbrk_base && (char*)p < sbrk_base + sbrked_mem)); - assert((n_mmaps > 0)); - assert(((size + offset) & (malloc_getpagesize-1)) == 0); - - /* Note the extra SIZE_SZ overhead as in mmap_chunk(). */ - new_size = (new_size + offset + SIZE_SZ + page_mask) & ~page_mask; - - cp = (char *)mremap((char *)p - offset, size + offset, new_size, 1); - - if (cp == (char *)-1) return 0; - - p = (mchunkptr)(cp + offset); - - assert(aligned_OK(chunk2mem(p))); - - assert((p->prev_size == offset)); - set_head(p, (new_size - offset)|IS_MMAPPED); - - mmapped_mem -= size + offset; - mmapped_mem += new_size; - if ((unsigned long)mmapped_mem > (unsigned long)max_mmapped_mem) - max_mmapped_mem = mmapped_mem; - if ((unsigned long)(mmapped_mem + sbrked_mem) > (unsigned long)max_total_mem) - max_total_mem = mmapped_mem + sbrked_mem; - return p; -} - -#endif /* HAVE_MREMAP */ - -#endif /* HAVE_MMAP */ - - - - -/* - Extend the top-most chunk by obtaining memory from system. - Main interface to sbrk (but see also malloc_trim). -*/ - -#if __STD_C -static void malloc_extend_top(INTERNAL_SIZE_T nb) -#else -static void malloc_extend_top(nb) INTERNAL_SIZE_T nb; -#endif -{ - char* brk; /* return value from sbrk */ - INTERNAL_SIZE_T front_misalign; /* unusable bytes at front of sbrked space */ - INTERNAL_SIZE_T correction; /* bytes for 2nd sbrk call */ - char* new_brk; /* return of 2nd sbrk call */ - INTERNAL_SIZE_T top_size; /* new size of top chunk */ - - mchunkptr old_top = top; /* Record state of old top */ - INTERNAL_SIZE_T old_top_size = chunksize(old_top); - char* old_end = (char*)(chunk_at_offset(old_top, old_top_size)); - - /* Pad request with top_pad plus minimal overhead */ - - INTERNAL_SIZE_T sbrk_size = nb + top_pad + MINSIZE; - unsigned long pagesz = malloc_getpagesize; - - /* If not the first time through, round to preserve page boundary */ - /* Otherwise, we need to correct to a page size below anyway. */ - /* (We also correct below if an intervening foreign sbrk call.) */ - - if (sbrk_base != (char*)(-1)) - sbrk_size = (sbrk_size + (pagesz - 1)) & ~(pagesz - 1); - - brk = (char*)(MORECORE (sbrk_size)); - - /* Fail if sbrk failed or if a foreign sbrk call killed our space */ - if (brk == (char*)(MORECORE_FAILURE) || - (brk < old_end && old_top != initial_top)) - return; - - sbrked_mem += sbrk_size; - - if (brk == old_end) /* can just add bytes to current top */ - { - top_size = sbrk_size + old_top_size; - set_head(top, top_size | PREV_INUSE); - } - else - { - if (sbrk_base == (char*)(-1)) /* First time through. Record base */ - sbrk_base = brk; - else /* Someone else called sbrk(). Count those bytes as sbrked_mem. */ - sbrked_mem += brk - (char*)old_end; - - /* Guarantee alignment of first new chunk made from this space */ - front_misalign = (unsigned long)chunk2mem(brk) & MALLOC_ALIGN_MASK; - if (front_misalign > 0) - { - correction = (MALLOC_ALIGNMENT) - front_misalign; - brk += correction; - } - else - correction = 0; - - /* Guarantee the next brk will be at a page boundary */ - - correction += ((((unsigned long)(brk + sbrk_size))+(pagesz-1)) & - ~(pagesz - 1)) - ((unsigned long)(brk + sbrk_size)); - - /* Allocate correction */ - new_brk = (char*)(MORECORE (correction)); - if (new_brk == (char*)(MORECORE_FAILURE)) return; - - sbrked_mem += correction; - - top = (mchunkptr)brk; - top_size = new_brk - brk + correction; - set_head(top, top_size | PREV_INUSE); - - if (old_top != initial_top) - { - - /* There must have been an intervening foreign sbrk call. */ - /* A double fencepost is necessary to prevent consolidation */ - - /* If not enough space to do this, then user did something very wrong */ - if (old_top_size < MINSIZE) - { - set_head(top, PREV_INUSE); /* will force null return from malloc */ - return; - } - - /* Also keep size a multiple of MALLOC_ALIGNMENT */ - old_top_size = (old_top_size - 3*SIZE_SZ) & ~MALLOC_ALIGN_MASK; - set_head_size(old_top, old_top_size); - chunk_at_offset(old_top, old_top_size )->size = - SIZE_SZ|PREV_INUSE; - chunk_at_offset(old_top, old_top_size + SIZE_SZ)->size = - SIZE_SZ|PREV_INUSE; - /* If possible, release the rest. */ - if (old_top_size >= MINSIZE) - fREe(chunk2mem(old_top)); - } - } - - if ((unsigned long)sbrked_mem > (unsigned long)max_sbrked_mem) - max_sbrked_mem = sbrked_mem; - if ((unsigned long)(mmapped_mem + sbrked_mem) > (unsigned long)max_total_mem) - max_total_mem = mmapped_mem + sbrked_mem; - - /* We always land on a page boundary */ - assert(((unsigned long)((char*)top + top_size) & (pagesz - 1)) == 0); -} - - - - -/* Main public routines */ - - -/* - Malloc Algorthim: - - The requested size is first converted into a usable form, `nb'. - This currently means to add 4 bytes overhead plus possibly more to - obtain 8-byte alignment and/or to obtain a size of at least - MINSIZE (currently 16 bytes), the smallest allocatable size. - (All fits are considered `exact' if they are within MINSIZE bytes.) - - From there, the first successful of the following steps is taken: - - 1. The bin corresponding to the request size is scanned, and if - a chunk of exactly the right size is found, it is taken. - - 2. The most recently remaindered chunk is used if it is big - enough. This is a form of (roving) first fit, used only in - the absence of exact fits. Runs of consecutive requests use - the remainder of the chunk used for the previous such request - whenever possible. This limited use of a first-fit style - allocation strategy tends to give contiguous chunks - coextensive lifetimes, which improves locality and can reduce - fragmentation in the long run. - - 3. Other bins are scanned in increasing size order, using a - chunk big enough to fulfill the request, and splitting off - any remainder. This search is strictly by best-fit; i.e., - the smallest (with ties going to approximately the least - recently used) chunk that fits is selected. - - 4. If large enough, the chunk bordering the end of memory - (`top') is split off. (This use of `top' is in accord with - the best-fit search rule. In effect, `top' is treated as - larger (and thus less well fitting) than any other available - chunk since it can be extended to be as large as necessary - (up to system limitations). - - 5. If the request size meets the mmap threshold and the - system supports mmap, and there are few enough currently - allocated mmapped regions, and a call to mmap succeeds, - the request is allocated via direct memory mapping. - - 6. Otherwise, the top of memory is extended by - obtaining more space from the system (normally using sbrk, - but definable to anything else via the MORECORE macro). - Memory is gathered from the system (in system page-sized - units) in a way that allows chunks obtained across different - sbrk calls to be consolidated, but does not require - contiguous memory. Thus, it should be safe to intersperse - mallocs with other sbrk calls. - - - All allocations are made from the the `lowest' part of any found - chunk. (The implementation invariant is that prev_inuse is - always true of any allocated chunk; i.e., that each allocated - chunk borders either a previously allocated and still in-use chunk, - or the base of its memory arena.) - -*/ - -#if __STD_C -Void_t* mALLOc(size_t bytes) -#else -Void_t* mALLOc(bytes) size_t bytes; -#endif -{ - mchunkptr victim; /* inspected/selected chunk */ - INTERNAL_SIZE_T victim_size; /* its size */ - int idx; /* index for bin traversal */ - mbinptr bin; /* associated bin */ - mchunkptr remainder; /* remainder from a split */ - long remainder_size; /* its size */ - int remainder_index; /* its bin index */ - unsigned long block; /* block traverser bit */ - int startidx; /* first bin of a traversed block */ - mchunkptr fwd; /* misc temp for linking */ - mchunkptr bck; /* misc temp for linking */ - mbinptr q; /* misc temp */ - - INTERNAL_SIZE_T nb; - - if ((long)bytes < 0) return 0; - - nb = request2size(bytes); /* padded request size; */ - - /* Check for exact match in a bin */ - - if (is_small_request(nb)) /* Faster version for small requests */ - { - idx = smallbin_index(nb); - - /* No traversal or size check necessary for small bins. */ - - q = bin_at(idx); - victim = last(q); - - /* Also scan the next one, since it would have a remainder < MINSIZE */ - if (victim == q) - { - q = next_bin(q); - victim = last(q); - } - if (victim != q) - { - victim_size = chunksize(victim); - unlink(victim, bck, fwd); - set_inuse_bit_at_offset(victim, victim_size); - check_malloced_chunk(victim, nb); - return chunk2mem(victim); - } - - idx += 2; /* Set for bin scan below. We've already scanned 2 bins. */ - - } - else - { - idx = bin_index(nb); - bin = bin_at(idx); - - for (victim = last(bin); victim != bin; victim = victim->bk) - { - victim_size = chunksize(victim); - remainder_size = victim_size - nb; - - if (remainder_size >= (long)MINSIZE) /* too big */ - { - --idx; /* adjust to rescan below after checking last remainder */ - break; - } - - else if (remainder_size >= 0) /* exact fit */ - { - unlink(victim, bck, fwd); - set_inuse_bit_at_offset(victim, victim_size); - check_malloced_chunk(victim, nb); - return chunk2mem(victim); - } - } - - ++idx; - - } - - /* Try to use the last split-off remainder */ - - if ( (victim = last_remainder->fd) != last_remainder) - { - victim_size = chunksize(victim); - remainder_size = victim_size - nb; - - if (remainder_size >= (long)MINSIZE) /* re-split */ - { - remainder = chunk_at_offset(victim, nb); - set_head(victim, nb | PREV_INUSE); - link_last_remainder(remainder); - set_head(remainder, remainder_size | PREV_INUSE); - set_foot(remainder, remainder_size); - check_malloced_chunk(victim, nb); - return chunk2mem(victim); - } - - clear_last_remainder; - - if (remainder_size >= 0) /* exhaust */ - { - set_inuse_bit_at_offset(victim, victim_size); - check_malloced_chunk(victim, nb); - return chunk2mem(victim); - } - - /* Else place in bin */ - - frontlink(victim, victim_size, remainder_index, bck, fwd); - } - - /* - If there are any possibly nonempty big-enough blocks, - search for best fitting chunk by scanning bins in blockwidth units. - */ - - if ( (block = idx2binblock(idx)) <= binblocks) - { - - /* Get to the first marked block */ - - if ( (block & binblocks) == 0) - { - /* force to an even block boundary */ - idx = (idx & ~(BINBLOCKWIDTH - 1)) + BINBLOCKWIDTH; - block <<= 1; - while ((block & binblocks) == 0) - { - idx += BINBLOCKWIDTH; - block <<= 1; - } - } - - /* For each possibly nonempty block ... */ - for (;;) - { - startidx = idx; /* (track incomplete blocks) */ - q = bin = bin_at(idx); - - /* For each bin in this block ... */ - do - { - /* Find and use first big enough chunk ... */ - - for (victim = last(bin); victim != bin; victim = victim->bk) - { - victim_size = chunksize(victim); - remainder_size = victim_size - nb; - - if (remainder_size >= (long)MINSIZE) /* split */ - { - remainder = chunk_at_offset(victim, nb); - set_head(victim, nb | PREV_INUSE); - unlink(victim, bck, fwd); - link_last_remainder(remainder); - set_head(remainder, remainder_size | PREV_INUSE); - set_foot(remainder, remainder_size); - check_malloced_chunk(victim, nb); - return chunk2mem(victim); - } - - else if (remainder_size >= 0) /* take */ - { - set_inuse_bit_at_offset(victim, victim_size); - unlink(victim, bck, fwd); - check_malloced_chunk(victim, nb); - return chunk2mem(victim); - } - - } - - bin = next_bin(bin); - - } while ((++idx & (BINBLOCKWIDTH - 1)) != 0); - - /* Clear out the block bit. */ - - do /* Possibly backtrack to try to clear a partial block */ - { - if ((startidx & (BINBLOCKWIDTH - 1)) == 0) - { - binblocks &= ~block; - break; - } - --startidx; - q = prev_bin(q); - } while (first(q) == q); - - /* Get to the next possibly nonempty block */ - - if ( (block <<= 1) <= binblocks && (block != 0) ) - { - while ((block & binblocks) == 0) - { - idx += BINBLOCKWIDTH; - block <<= 1; - } - } - else - break; - } - } - - - /* Try to use top chunk */ - - /* Require that there be a remainder, ensuring top always exists */ - if ( (remainder_size = chunksize(top) - nb) < (long)MINSIZE) - { - -#if HAVE_MMAP - /* If big and would otherwise need to extend, try to use mmap instead */ - if ((unsigned long)nb >= (unsigned long)mmap_threshold && - (victim = mmap_chunk(nb)) != 0) - return chunk2mem(victim); -#endif - - /* Try to extend */ - malloc_extend_top(nb); - if ( (remainder_size = chunksize(top) - nb) < (long)MINSIZE) - return 0; /* propagate failure */ - } - - victim = top; - set_head(victim, nb | PREV_INUSE); - top = chunk_at_offset(victim, nb); - set_head(top, remainder_size | PREV_INUSE); - check_malloced_chunk(victim, nb); - return chunk2mem(victim); - -} - - - - -/* - - free() algorithm : - - cases: - - 1. free(0) has no effect. - - 2. If the chunk was allocated via mmap, it is release via munmap(). - - 3. If a returned chunk borders the current high end of memory, - it is consolidated into the top, and if the total unused - topmost memory exceeds the trim threshold, malloc_trim is - called. - - 4. Other chunks are consolidated as they arrive, and - placed in corresponding bins. (This includes the case of - consolidating with the current `last_remainder'). - -*/ - - -#if __STD_C -void fREe(Void_t* mem) -#else -void fREe(mem) Void_t* mem; -#endif -{ - mchunkptr p; /* chunk corresponding to mem */ - INTERNAL_SIZE_T hd; /* its head field */ - INTERNAL_SIZE_T sz; /* its size */ - int idx; /* its bin index */ - mchunkptr next; /* next contiguous chunk */ - INTERNAL_SIZE_T nextsz; /* its size */ - INTERNAL_SIZE_T prevsz; /* size of previous contiguous chunk */ - mchunkptr bck; /* misc temp for linking */ - mchunkptr fwd; /* misc temp for linking */ - int islr; /* track whether merging with last_remainder */ - - if (mem == 0) /* free(0) has no effect */ - return; - - p = mem2chunk(mem); - hd = p->size; - -#if HAVE_MMAP - if (hd & IS_MMAPPED) /* release mmapped memory. */ - { - munmap_chunk(p); - return; - } -#endif - - check_inuse_chunk(p); - - sz = hd & ~PREV_INUSE; - next = chunk_at_offset(p, sz); - nextsz = chunksize(next); - - if (next == top) /* merge with top */ - { - sz += nextsz; - - if (!(hd & PREV_INUSE)) /* consolidate backward */ - { - prevsz = p->prev_size; - p = chunk_at_offset(p, -((long) prevsz)); - sz += prevsz; - unlink(p, bck, fwd); - } - - set_head(p, sz | PREV_INUSE); - top = p; - if ((unsigned long)(sz) >= (unsigned long)trim_threshold) - malloc_trim(top_pad); - return; - } - - set_head(next, nextsz); /* clear inuse bit */ - - islr = 0; - - if (!(hd & PREV_INUSE)) /* consolidate backward */ - { - prevsz = p->prev_size; - p = chunk_at_offset(p, -((long) prevsz)); - sz += prevsz; - - if (p->fd == last_remainder) /* keep as last_remainder */ - islr = 1; - else - unlink(p, bck, fwd); - } - - if (!(inuse_bit_at_offset(next, nextsz))) /* consolidate forward */ - { - sz += nextsz; - - if (!islr && next->fd == last_remainder) /* re-insert last_remainder */ - { - islr = 1; - link_last_remainder(p); - } - else - unlink(next, bck, fwd); - } - - - set_head(p, sz | PREV_INUSE); - set_foot(p, sz); - if (!islr) - frontlink(p, sz, idx, bck, fwd); -} - - - - - -/* - - Realloc algorithm: - - Chunks that were obtained via mmap cannot be extended or shrunk - unless HAVE_MREMAP is defined, in which case mremap is used. - Otherwise, if their reallocation is for additional space, they are - copied. If for less, they are just left alone. - - Otherwise, if the reallocation is for additional space, and the - chunk can be extended, it is, else a malloc-copy-free sequence is - taken. There are several different ways that a chunk could be - extended. All are tried: - - * Extending forward into following adjacent free chunk. - * Shifting backwards, joining preceding adjacent space - * Both shifting backwards and extending forward. - * Extending into newly sbrked space - - Unless the #define REALLOC_ZERO_BYTES_FREES is set, realloc with a - size argument of zero (re)allocates a minimum-sized chunk. - - If the reallocation is for less space, and the new request is for - a `small' (<512 bytes) size, then the newly unused space is lopped - off and freed. - - The old unix realloc convention of allowing the last-free'd chunk - to be used as an argument to realloc is no longer supported. - I don't know of any programs still relying on this feature, - and allowing it would also allow too many other incorrect - usages of realloc to be sensible. - - -*/ - - -#if __STD_C -Void_t* rEALLOc(Void_t* oldmem, size_t bytes) -#else -Void_t* rEALLOc(oldmem, bytes) Void_t* oldmem; size_t bytes; -#endif -{ - INTERNAL_SIZE_T nb; /* padded request size */ - - mchunkptr oldp; /* chunk corresponding to oldmem */ - INTERNAL_SIZE_T oldsize; /* its size */ - - mchunkptr newp; /* chunk to return */ - INTERNAL_SIZE_T newsize; /* its size */ - Void_t* newmem; /* corresponding user mem */ - - mchunkptr next; /* next contiguous chunk after oldp */ - INTERNAL_SIZE_T nextsize; /* its size */ - - mchunkptr prev; /* previous contiguous chunk before oldp */ - INTERNAL_SIZE_T prevsize; /* its size */ - - mchunkptr remainder; /* holds split off extra space from newp */ - INTERNAL_SIZE_T remainder_size; /* its size */ - - mchunkptr bck; /* misc temp for linking */ - mchunkptr fwd; /* misc temp for linking */ - -#ifdef REALLOC_ZERO_BYTES_FREES - if (bytes == 0) { fREe(oldmem); return 0; } -#endif - - if ((long)bytes < 0) return 0; - - /* realloc of null is supposed to be same as malloc */ - if (oldmem == 0) return mALLOc(bytes); - - newp = oldp = mem2chunk(oldmem); - newsize = oldsize = chunksize(oldp); - - - nb = request2size(bytes); - -#if HAVE_MMAP - if (chunk_is_mmapped(oldp)) - { -#if HAVE_MREMAP - newp = mremap_chunk(oldp, nb); - if(newp) return chunk2mem(newp); -#endif - /* Note the extra SIZE_SZ overhead. */ - if(oldsize - SIZE_SZ >= nb) return oldmem; /* do nothing */ - /* Must alloc, copy, free. */ - newmem = mALLOc(bytes); - if (newmem == 0) return 0; /* propagate failure */ - MALLOC_COPY(newmem, oldmem, oldsize - 2*SIZE_SZ); - munmap_chunk(oldp); - return newmem; - } -#endif - - check_inuse_chunk(oldp); - - if ((long)(oldsize) < (long)(nb)) - { - - /* Try expanding forward */ - - next = chunk_at_offset(oldp, oldsize); - if (next == top || !inuse(next)) - { - nextsize = chunksize(next); - - /* Forward into top only if a remainder */ - if (next == top) - { - if ((long)(nextsize + newsize) >= (long)(nb + MINSIZE)) - { - newsize += nextsize; - top = chunk_at_offset(oldp, nb); - set_head(top, (newsize - nb) | PREV_INUSE); - set_head_size(oldp, nb); - return chunk2mem(oldp); - } - } - - /* Forward into next chunk */ - else if (((long)(nextsize + newsize) >= (long)(nb))) - { - unlink(next, bck, fwd); - newsize += nextsize; - goto split; - } - } - else - { - next = 0; - nextsize = 0; - } - - /* Try shifting backwards. */ - - if (!prev_inuse(oldp)) - { - prev = prev_chunk(oldp); - prevsize = chunksize(prev); - - /* try forward + backward first to save a later consolidation */ - - if (next != 0) - { - /* into top */ - if (next == top) - { - if ((long)(nextsize + prevsize + newsize) >= (long)(nb + MINSIZE)) - { - unlink(prev, bck, fwd); - newp = prev; - newsize += prevsize + nextsize; - newmem = chunk2mem(newp); - MALLOC_COPY(newmem, oldmem, oldsize - SIZE_SZ); - top = chunk_at_offset(newp, nb); - set_head(top, (newsize - nb) | PREV_INUSE); - set_head_size(newp, nb); - return newmem; - } - } - - /* into next chunk */ - else if (((long)(nextsize + prevsize + newsize) >= (long)(nb))) - { - unlink(next, bck, fwd); - unlink(prev, bck, fwd); - newp = prev; - newsize += nextsize + prevsize; - newmem = chunk2mem(newp); - MALLOC_COPY(newmem, oldmem, oldsize - SIZE_SZ); - goto split; - } - } - - /* backward only */ - if (prev != 0 && (long)(prevsize + newsize) >= (long)nb) - { - unlink(prev, bck, fwd); - newp = prev; - newsize += prevsize; - newmem = chunk2mem(newp); - MALLOC_COPY(newmem, oldmem, oldsize - SIZE_SZ); - goto split; - } - } - - /* Must allocate */ - - newmem = mALLOc (bytes); - - if (newmem == 0) /* propagate failure */ - return 0; - - /* Avoid copy if newp is next chunk after oldp. */ - /* (This can only happen when new chunk is sbrk'ed.) */ - - if ( (newp = mem2chunk(newmem)) == next_chunk(oldp)) - { - newsize += chunksize(newp); - newp = oldp; - goto split; - } - - /* Otherwise copy, free, and exit */ - MALLOC_COPY(newmem, oldmem, oldsize - SIZE_SZ); - fREe(oldmem); - return newmem; - } - - - split: /* split off extra room in old or expanded chunk */ - - if (newsize - nb >= MINSIZE) /* split off remainder */ - { - remainder = chunk_at_offset(newp, nb); - remainder_size = newsize - nb; - set_head_size(newp, nb); - set_head(remainder, remainder_size | PREV_INUSE); - set_inuse_bit_at_offset(remainder, remainder_size); - fREe(chunk2mem(remainder)); /* let free() deal with it */ - } - else - { - set_head_size(newp, newsize); - set_inuse_bit_at_offset(newp, newsize); - } - - check_inuse_chunk(newp); - return chunk2mem(newp); -} - - - - -/* - - memalign algorithm: - - memalign requests more than enough space from malloc, finds a spot - within that chunk that meets the alignment request, and then - possibly frees the leading and trailing space. - - The alignment argument must be a power of two. This property is not - checked by memalign, so misuse may result in random runtime errors. - - 8-byte alignment is guaranteed by normal malloc calls, so don't - bother calling memalign with an argument of 8 or less. - - Overreliance on memalign is a sure way to fragment space. - -*/ - - -#if __STD_C -Void_t* mEMALIGn(size_t alignment, size_t bytes) -#else -Void_t* mEMALIGn(alignment, bytes) size_t alignment; size_t bytes; -#endif -{ - INTERNAL_SIZE_T nb; /* padded request size */ - char* m; /* memory returned by malloc call */ - mchunkptr p; /* corresponding chunk */ - char* brk; /* alignment point within p */ - mchunkptr newp; /* chunk to return */ - INTERNAL_SIZE_T newsize; /* its size */ - INTERNAL_SIZE_T leadsize; /* leading space befor alignment point */ - mchunkptr remainder; /* spare room at end to split off */ - long remainder_size; /* its size */ - - if ((long)bytes < 0) return 0; - - /* If need less alignment than we give anyway, just relay to malloc */ - - if (alignment <= MALLOC_ALIGNMENT) return mALLOc(bytes); - - /* Otherwise, ensure that it is at least a minimum chunk size */ - - if (alignment < MINSIZE) alignment = MINSIZE; - - /* Call malloc with worst case padding to hit alignment. */ - - nb = request2size(bytes); - m = (char*)(mALLOc(nb + alignment + MINSIZE)); - - if (m == 0) return 0; /* propagate failure */ - - p = mem2chunk(m); - - if ((((unsigned long)(m)) % alignment) == 0) /* aligned */ - { -#if HAVE_MMAP - if(chunk_is_mmapped(p)) - return chunk2mem(p); /* nothing more to do */ -#endif - } - else /* misaligned */ - { - /* - Find an aligned spot inside chunk. - Since we need to give back leading space in a chunk of at - least MINSIZE, if the first calculation places us at - a spot with less than MINSIZE leader, we can move to the - next aligned spot -- we've allocated enough total room so that - this is always possible. - */ - - brk = (char*)mem2chunk(((unsigned long)(m + alignment - 1)) & -((signed) alignment)); - if ((long)(brk - (char*)(p)) < MINSIZE) brk = brk + alignment; - - newp = (mchunkptr)brk; - leadsize = brk - (char*)(p); - newsize = chunksize(p) - leadsize; - -#if HAVE_MMAP - if(chunk_is_mmapped(p)) - { - newp->prev_size = p->prev_size + leadsize; - set_head(newp, newsize|IS_MMAPPED); - return chunk2mem(newp); - } -#endif - - /* give back leader, use the rest */ - - set_head(newp, newsize | PREV_INUSE); - set_inuse_bit_at_offset(newp, newsize); - set_head_size(p, leadsize); - fREe(chunk2mem(p)); - p = newp; - - assert (newsize >= nb && (((unsigned long)(chunk2mem(p))) % alignment) == 0); - } - - /* Also give back spare room at the end */ - - remainder_size = chunksize(p) - nb; - - if (remainder_size >= (long)MINSIZE) - { - remainder = chunk_at_offset(p, nb); - set_head(remainder, remainder_size | PREV_INUSE); - set_head_size(p, nb); - fREe(chunk2mem(remainder)); - } - - check_inuse_chunk(p); - return chunk2mem(p); - -} - - - - -/* - valloc just invokes memalign with alignment argument equal - to the page size of the system (or as near to this as can - be figured out from all the includes/defines above.) -*/ - -#if __STD_C -Void_t* vALLOc(size_t bytes) -#else -Void_t* vALLOc(bytes) size_t bytes; -#endif -{ - return mEMALIGn (malloc_getpagesize, bytes); -} - -/* - pvalloc just invokes valloc for the nearest pagesize - that will accommodate request -*/ - - -#if __STD_C -Void_t* pvALLOc(size_t bytes) -#else -Void_t* pvALLOc(bytes) size_t bytes; -#endif -{ - size_t pagesize = malloc_getpagesize; - return mEMALIGn (pagesize, (bytes + pagesize - 1) & ~(pagesize - 1)); -} - -/* - - calloc calls malloc, then zeroes out the allocated chunk. - -*/ - -#if __STD_C -Void_t* cALLOc(size_t n, size_t elem_size) -#else -Void_t* cALLOc(n, elem_size) size_t n; size_t elem_size; -#endif -{ - mchunkptr p; - INTERNAL_SIZE_T csz; - - INTERNAL_SIZE_T sz = n * elem_size; - - - /* check if expand_top called, in which case don't need to clear */ -#if MORECORE_CLEARS - mchunkptr oldtop = top; - INTERNAL_SIZE_T oldtopsize = chunksize(top); -#endif - Void_t* mem = mALLOc (sz); - - if ((long)n < 0) return 0; - - if (mem == 0) - return 0; - else - { - p = mem2chunk(mem); - - /* Two optional cases in which clearing not necessary */ - - -#if HAVE_MMAP - if (chunk_is_mmapped(p)) return mem; -#endif - - csz = chunksize(p); - -#if MORECORE_CLEARS - if (p == oldtop && csz > oldtopsize) - { - /* clear only the bytes from non-freshly-sbrked memory */ - csz = oldtopsize; - } -#endif - - MALLOC_ZERO(mem, csz - SIZE_SZ); - return mem; - } -} - -/* - - cfree just calls free. It is needed/defined on some systems - that pair it with calloc, presumably for odd historical reasons. - -*/ - -#if !defined(INTERNAL_LINUX_C_LIB) || !defined(__ELF__) -#if __STD_C -void cfree(Void_t *mem) -#else -void cfree(mem) Void_t *mem; -#endif -{ - fREe(mem); -} -#endif - - - -/* - - Malloc_trim gives memory back to the system (via negative - arguments to sbrk) if there is unused memory at the `high' end of - the malloc pool. You can call this after freeing large blocks of - memory to potentially reduce the system-level memory requirements - of a program. However, it cannot guarantee to reduce memory. Under - some allocation patterns, some large free blocks of memory will be - locked between two used chunks, so they cannot be given back to - the system. - - The `pad' argument to malloc_trim represents the amount of free - trailing space to leave untrimmed. If this argument is zero, - only the minimum amount of memory to maintain internal data - structures will be left (one page or less). Non-zero arguments - can be supplied to maintain enough trailing space to service - future expected allocations without having to re-obtain memory - from the system. - - Malloc_trim returns 1 if it actually released any memory, else 0. - -*/ - -#if __STD_C -int malloc_trim(size_t pad) -#else -int malloc_trim(pad) size_t pad; -#endif -{ - long top_size; /* Amount of top-most memory */ - long extra; /* Amount to release */ - char* current_brk; /* address returned by pre-check sbrk call */ - char* new_brk; /* address returned by negative sbrk call */ - - unsigned long pagesz = malloc_getpagesize; - - top_size = chunksize(top); - extra = ((top_size - pad - MINSIZE + (pagesz-1)) / pagesz - 1) * pagesz; - - if (extra < (long)pagesz) /* Not enough memory to release */ - return 0; - - else - { - /* Test to make sure no one else called sbrk */ - current_brk = (char*)(MORECORE (0)); - if (current_brk != (char*)(top) + top_size) - return 0; /* Apparently we don't own memory; must fail */ - - else - { - new_brk = (char*)(MORECORE (-extra)); - - if (new_brk == (char*)(MORECORE_FAILURE)) /* sbrk failed? */ - { - /* Try to figure out what we have */ - current_brk = (char*)(MORECORE (0)); - top_size = current_brk - (char*)top; - if (top_size >= (long)MINSIZE) /* if not, we are very very dead! */ - { - sbrked_mem = current_brk - sbrk_base; - set_head(top, top_size | PREV_INUSE); - } - check_chunk(top); - return 0; - } - - else - { - /* Success. Adjust top accordingly. */ - set_head(top, (top_size - extra) | PREV_INUSE); - sbrked_mem -= extra; - check_chunk(top); - return 1; - } - } - } -} - - - -/* - malloc_usable_size: - - This routine tells you how many bytes you can actually use in an - allocated chunk, which may be more than you requested (although - often not). You can use this many bytes without worrying about - overwriting other allocated objects. Not a particularly great - programming practice, but still sometimes useful. - -*/ - -#if __STD_C -size_t malloc_usable_size(Void_t* mem) -#else -size_t malloc_usable_size(mem) Void_t* mem; -#endif -{ - mchunkptr p; - if (mem == 0) - return 0; - else - { - p = mem2chunk(mem); - if(!chunk_is_mmapped(p)) - { - if (!inuse(p)) return 0; - check_inuse_chunk(p); - return chunksize(p) - SIZE_SZ; - } - return chunksize(p) - 2*SIZE_SZ; - } -} - - - - -/* Utility to update current_mallinfo for malloc_stats and mallinfo() */ - -static void malloc_update_mallinfo() -{ - int i; - mbinptr b; - mchunkptr p; -#if DEBUG - mchunkptr q; -#endif - - INTERNAL_SIZE_T avail = chunksize(top); - int navail = ((long)(avail) >= (long)MINSIZE)? 1 : 0; - - for (i = 1; i < NAV; ++i) - { - b = bin_at(i); - for (p = last(b); p != b; p = p->bk) - { -#if DEBUG - check_free_chunk(p); - for (q = next_chunk(p); - q < top && inuse(q) && (long)(chunksize(q)) >= (long)MINSIZE; - q = next_chunk(q)) - check_inuse_chunk(q); -#endif - avail += chunksize(p); - navail++; - } - } - - current_mallinfo.ordblks = navail; - current_mallinfo.uordblks = sbrked_mem - avail; - current_mallinfo.fordblks = avail; - current_mallinfo.hblks = n_mmaps; - current_mallinfo.hblkhd = mmapped_mem; - current_mallinfo.keepcost = chunksize(top); - -} - - - -/* - - malloc_stats: - - Prints on stderr the amount of space obtain from the system (both - via sbrk and mmap), the maximum amount (which may be more than - current if malloc_trim and/or munmap got called), the maximum - number of simultaneous mmap regions used, and the current number - of bytes allocated via malloc (or realloc, etc) but not yet - freed. (Note that this is the number of bytes allocated, not the - number requested. It will be larger than the number requested - because of alignment and bookkeeping overhead.) - -*/ - -void malloc_stats() -{ - malloc_update_mallinfo(); - fprintf(stderr, "max system bytes = %10u\n", - (unsigned int)(max_total_mem)); - fprintf(stderr, "system bytes = %10u\n", - (unsigned int)(sbrked_mem + mmapped_mem)); - fprintf(stderr, "in use bytes = %10u\n", - (unsigned int)(current_mallinfo.uordblks + mmapped_mem)); -#if HAVE_MMAP - fprintf(stderr, "max mmap regions = %10u\n", - (unsigned int)max_n_mmaps); -#endif -} - -/* - mallinfo returns a copy of updated current mallinfo. -*/ - -struct mallinfo mALLINFo() -{ - malloc_update_mallinfo(); - return current_mallinfo; -} - - - - -/* - mallopt: - - mallopt is the general SVID/XPG interface to tunable parameters. - The format is to provide a (parameter-number, parameter-value) pair. - mallopt then sets the corresponding parameter to the argument - value if it can (i.e., so long as the value is meaningful), - and returns 1 if successful else 0. - - See descriptions of tunable parameters above. - -*/ - -#if __STD_C -int mALLOPt(int param_number, int value) -#else -int mALLOPt(param_number, value) int param_number; int value; -#endif -{ - switch(param_number) - { - case M_TRIM_THRESHOLD: - trim_threshold = value; return 1; - case M_TOP_PAD: - top_pad = value; return 1; - case M_MMAP_THRESHOLD: - mmap_threshold = value; return 1; - case M_MMAP_MAX: -#if HAVE_MMAP - n_mmaps_max = value; return 1; -#else - if (value != 0) return 0; else n_mmaps_max = value; return 1; -#endif - - default: - return 0; - } -} - -/* - -History: - - V2.6.6 Sun Dec 5 07:42:19 1999 Doug Lea (dl at gee) - * return null for negative arguments - * Added Several WIN32 cleanups from Martin C. Fong <mcfong@yahoo.com> - * Add 'LACKS_SYS_PARAM_H' for those systems without 'sys/param.h' - (e.g. WIN32 platforms) - * Cleanup up header file inclusion for WIN32 platforms - * Cleanup code to avoid Microsoft Visual C++ compiler complaints - * Add 'USE_DL_PREFIX' to quickly allow co-existence with existing - memory allocation routines - * Set 'malloc_getpagesize' for WIN32 platforms (needs more work) - * Use 'assert' rather than 'ASSERT' in WIN32 code to conform to - usage of 'assert' in non-WIN32 code - * Improve WIN32 'sbrk()' emulation's 'findRegion()' routine to - avoid infinite loop - * Always call 'fREe()' rather than 'free()' - - V2.6.5 Wed Jun 17 15:57:31 1998 Doug Lea (dl at gee) - * Fixed ordering problem with boundary-stamping - - V2.6.3 Sun May 19 08:17:58 1996 Doug Lea (dl at gee) - * Added pvalloc, as recommended by H.J. Liu - * Added 64bit pointer support mainly from Wolfram Gloger - * Added anonymously donated WIN32 sbrk emulation - * Malloc, calloc, getpagesize: add optimizations from Raymond Nijssen - * malloc_extend_top: fix mask error that caused wastage after - foreign sbrks - * Add linux mremap support code from HJ Liu - - V2.6.2 Tue Dec 5 06:52:55 1995 Doug Lea (dl at gee) - * Integrated most documentation with the code. - * Add support for mmap, with help from - Wolfram Gloger (Gloger@lrz.uni-muenchen.de). - * Use last_remainder in more cases. - * Pack bins using idea from colin@nyx10.cs.du.edu - * Use ordered bins instead of best-fit threshhold - * Eliminate block-local decls to simplify tracing and debugging. - * Support another case of realloc via move into top - * Fix error occuring when initial sbrk_base not word-aligned. - * Rely on page size for units instead of SBRK_UNIT to - avoid surprises about sbrk alignment conventions. - * Add mallinfo, mallopt. Thanks to Raymond Nijssen - (raymond@es.ele.tue.nl) for the suggestion. - * Add `pad' argument to malloc_trim and top_pad mallopt parameter. - * More precautions for cases where other routines call sbrk, - courtesy of Wolfram Gloger (Gloger@lrz.uni-muenchen.de). - * Added macros etc., allowing use in linux libc from - H.J. Lu (hjl@gnu.ai.mit.edu) - * Inverted this history list - - V2.6.1 Sat Dec 2 14:10:57 1995 Doug Lea (dl at gee) - * Re-tuned and fixed to behave more nicely with V2.6.0 changes. - * Removed all preallocation code since under current scheme - the work required to undo bad preallocations exceeds - the work saved in good cases for most test programs. - * No longer use return list or unconsolidated bins since - no scheme using them consistently outperforms those that don't - given above changes. - * Use best fit for very large chunks to prevent some worst-cases. - * Added some support for debugging - - V2.6.0 Sat Nov 4 07:05:23 1995 Doug Lea (dl at gee) - * Removed footers when chunks are in use. Thanks to - Paul Wilson (wilson@cs.texas.edu) for the suggestion. - - V2.5.4 Wed Nov 1 07:54:51 1995 Doug Lea (dl at gee) - * Added malloc_trim, with help from Wolfram Gloger - (wmglo@Dent.MED.Uni-Muenchen.DE). - - V2.5.3 Tue Apr 26 10:16:01 1994 Doug Lea (dl at g) - - V2.5.2 Tue Apr 5 16:20:40 1994 Doug Lea (dl at g) - * realloc: try to expand in both directions - * malloc: swap order of clean-bin strategy; - * realloc: only conditionally expand backwards - * Try not to scavenge used bins - * Use bin counts as a guide to preallocation - * Occasionally bin return list chunks in first scan - * Add a few optimizations from colin@nyx10.cs.du.edu - - V2.5.1 Sat Aug 14 15:40:43 1993 Doug Lea (dl at g) - * faster bin computation & slightly different binning - * merged all consolidations to one part of malloc proper - (eliminating old malloc_find_space & malloc_clean_bin) - * Scan 2 returns chunks (not just 1) - * Propagate failure in realloc if malloc returns 0 - * Add stuff to allow compilation on non-ANSI compilers - from kpv@research.att.com - - V2.5 Sat Aug 7 07:41:59 1993 Doug Lea (dl at g.oswego.edu) - * removed potential for odd address access in prev_chunk - * removed dependency on getpagesize.h - * misc cosmetics and a bit more internal documentation - * anticosmetics: mangled names in macros to evade debugger strangeness - * tested on sparc, hp-700, dec-mips, rs6000 - with gcc & native cc (hp, dec only) allowing - Detlefs & Zorn comparison study (in SIGPLAN Notices.) - - Trial version Fri Aug 28 13:14:29 1992 Doug Lea (dl at g.oswego.edu) - * Based loosely on libg++-1.2X malloc. (It retains some of the overall - structure of old version, but most details differ.) - -*/ |