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Diffstat (limited to 'common/dlmalloc.c')
| -rw-r--r-- | common/dlmalloc.c | 1021 |
1 files changed, 0 insertions, 1021 deletions
diff --git a/common/dlmalloc.c b/common/dlmalloc.c index 20c206913c..968bf9d421 100644 --- a/common/dlmalloc.c +++ b/common/dlmalloc.c @@ -1,952 +1,6 @@ -#if 0 /* Moved to malloc.h */ -/* ---------- 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. - 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. - -*/ - -#ifdef 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 ------------ */ -#else /* Moved to malloc.h */ #include <malloc.h> -#if 0 -#if __STD_C -static void malloc_update_mallinfo (void); -void malloc_stats (void); -#else -static void malloc_update_mallinfo (); -void malloc_stats(); -#endif -#endif /* 0 */ -#endif /* 0 */ /* Moved to malloc.h */ #include <common.h> DECLARE_GLOBAL_DATA_PTR; @@ -1589,9 +643,6 @@ static struct mallinfo current_mallinfo = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }; /* Tracking mmaps */ -#if 0 -static unsigned int n_mmaps = 0; -#endif /* 0 */ static unsigned long mmapped_mem = 0; #if HAVE_MMAP static unsigned int max_n_mmaps = 0; @@ -1621,9 +672,6 @@ static void do_check_chunk(mchunkptr p) static void do_check_chunk(p) mchunkptr p; #endif { -#if 0 /* causes warnings because assert() is off */ - INTERNAL_SIZE_T sz = p->size & ~PREV_INUSE; -#endif /* 0 */ /* No checkable chunk is mmapped */ assert(!chunk_is_mmapped(p)); @@ -1645,9 +693,6 @@ static void do_check_free_chunk(p) mchunkptr p; #endif { INTERNAL_SIZE_T sz = p->size & ~PREV_INUSE; -#if 0 /* causes warnings because assert() is off */ - mchunkptr next = chunk_at_offset(p, sz); -#endif /* 0 */ do_check_chunk(p); @@ -1711,10 +756,6 @@ static void do_check_malloced_chunk(mchunkptr p, INTERNAL_SIZE_T s) static void do_check_malloced_chunk(p, s) mchunkptr p; INTERNAL_SIZE_T s; #endif { -#if 0 /* causes warnings because assert() is off */ - INTERNAL_SIZE_T sz = p->size & ~PREV_INUSE; - long room = sz - s; -#endif /* 0 */ do_check_inuse_chunk(p); @@ -3066,45 +2107,6 @@ size_t malloc_usable_size(mem) Void_t* mem; /* Utility to update current_mallinfo for malloc_stats and mallinfo() */ -#if 0 -static void malloc_update_mallinfo() -{ - int i; - mbinptr b; - mchunkptr p; -#ifdef 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) - { -#ifdef 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); - -} -#endif /* 0 */ @@ -3123,34 +2125,11 @@ static void malloc_update_mallinfo() */ -#if 0 -void malloc_stats() -{ - malloc_update_mallinfo(); - printf("max system bytes = %10u\n", - (unsigned int)(max_total_mem)); - printf("system bytes = %10u\n", - (unsigned int)(sbrked_mem + mmapped_mem)); - printf("in use bytes = %10u\n", - (unsigned int)(current_mallinfo.uordblks + mmapped_mem)); -#if HAVE_MMAP - printf("max mmap regions = %10u\n", - (unsigned int)max_n_mmaps); -#endif -} -#endif /* 0 */ /* mallinfo returns a copy of updated current mallinfo. */ -#if 0 -struct mallinfo mALLINFo() -{ - malloc_update_mallinfo(); - return current_mallinfo; -} -#endif /* 0 */ |