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Diffstat (limited to 'src/libs/xpcom18a4/xpcom/build/malloc.c')
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diff --git a/src/libs/xpcom18a4/xpcom/build/malloc.c b/src/libs/xpcom18a4/xpcom/build/malloc.c new file mode 100644 index 00000000..96691829 --- /dev/null +++ b/src/libs/xpcom18a4/xpcom/build/malloc.c @@ -0,0 +1,5126 @@ +#define USE_MALLOC_LOCK +#define DEFAULT_TRIM_THRESHOLD (256 * 1024) + +/* ---------- To make a malloc.h, start cutting here ------------ */ + +/* + **************************************************************** + * THIS IS A PRERELEASE. It has not yet been tested adequately. * + * If you use it, please send back comments, suggestions, * + * performance reports, etc. * + **************************************************************** +*/ + +/* + A version (aka dlmalloc) of malloc/free/realloc written by Doug + Lea and released to the public domain. Use this code without + permission or acknowledgement in any way you wish. Send questions, + comments, complaints, performance data, etc to dl@cs.oswego.edu + +* VERSION 2.7.0pre7 Wed Jan 10 13:33:01 2001 Doug Lea (dl at gee) + + Note: There may be an updated version of this malloc obtainable at + ftp://gee.cs.oswego.edu/pub/misc/malloc.c + Check before installing! + +* Quickstart + + This library is all in one file to simplify the most common usage: + ftp it, compile it (-O), and link it into another program. All + of the compile-time options default to reasonable values for use on + most unix platforms. Compile -DWIN32 for reasonable defaults on windows. + You might later want to step through various compile options. + +* 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 malloc-intensive programs. + + The main properties of the algorithms are: + * For large (>= 512 bytes) requests, it is a pure best-fit allocator, + with ties normally decided via FIFO (i.e. least recently used). + * For small (<= 64 bytes by default) requests, it is a caching + allocator, that maintains pools of quickly recycled chunks. + * In between, and for combinations of large and small requests, it does + the best it can trying to meet both goals at once. + + Compared to 2.6.X versions, this version is generally faster, + especially for programs that allocate and free many small chunks. + + For a longer but slightly out of date high-level description, see + http://gee.cs.oswego.edu/dl/html/malloc.html + + You may already by default be using a c library containing a malloc + that is somehow based on some version of this malloc (for example in + linux). You might still want to use the one in this file in order to + customize settings or to avoid overheads associated with library + versions. + +* 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: + + Assumed pointer representation: 4 or 8 bytes + (Thanks to Wolfram Gloger for contributing most of the + changes supporting dual 4/8.) + + Assumed size_t representation: 4 or 8 bytes + Note that size_t is allowed to be 4 bytes even if pointers are 8. + You can adjust this by defining INTERNAL_SIZE_T + + Alignment: 2 * sizeof(size_t) + (i.e., 8 byte alignment with 4byte size_t). This suffices for + nearly all current machines and C compilers. However, you can + define MALLOC_ALIGNMENT to be wider than this if necessary. + + Minimum overhead per allocated chunk: 4 or 8 bytes + Each malloced chunk has a hidden word of overhead 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. + + The maximum overhead wastage (i.e., number of extra bytes + allocated than were requested in malloc) is less than or equal + to the minimum size, except for requests >= mmap_threshold that + are serviced via mmap(), where the worst case wastage is 2 * + sizeof(size_t) bytes plus the remainder from a system page (the + minimal mmap unit); typically 4096 bytes. + + Maximum allocated size: 4-byte size_t: 2^31 minus about two pages + 8-byte size_t: 2^63 minus about two pages + + It is assumed that (possibly signed) size_t 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. The ISO C standard says that it must be + unsigned, but a few systems are known not to adhere to this. + Additionally, even when size_t is unsigned, sbrk (which is by + default used to obtain memory from system) accepts signed + arguments, and may not be able to handle size_t-wide arguments + with negative sign bit. To be conservative, values that would + appear as negative after accounting for overhead and alignment + are rejected. + + Requests for sizes outside this range will perform an optional + failure action and then return null. (Requests may also + also fail because a system is out of memory.) + + Thread-safety: NOT thread-safe unless USE_MALLOC_LOCK defined + + When USE_MALLOC_LOCK is defined, wrappers are created to + surround every public call with either a pthread mutex or + a win32 critical section (depending on WIN32). This is not + especially fast, and can be a major bottleneck in programs with + many threads. It is designed only to provide minimal protection + in concurrent environments, and to provide a basis for + extensions. If you are using malloc in a concurrent program, + you would be far better off obtaining ptmalloc, which is + derived from a version of this malloc, and is well-tuned for + concurrent programs. (See http://www.malloc.de) + + Compliance: I believe it is compliant with the 1997 Single Unix Specification + + (See http://www.opennc.org). Probably other standards as well. + +* Limitations + + Here are some features that are NOT currently supported + + * No automated mechanism for fully checking that all accesses + to malloced memory stay within their bounds. However, there + are several add-ons and adaptations of this or other mallocs + available that do this. + * 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 also report using it in stand-alone embedded systems. + + The implementation is in straight, hand-tuned ANSI C. It is not + at all modular. (Sorry!) It uses a lot of macros. To be at all + usable, this code should be compiled using an optimizing compiler + (for example gcc -O3) that can simplify expressions and control + paths. (FAQ: some macros import variables as arguments rather than + declare locals because people reported that some debuggers + otherwise get confused.) + + OPTION DEFAULT VALUE + + Compilation Environment options: + + __STD_C derived from C compiler defines + WIN32 NOT defined + HAVE_MEMCPY defined + USE_MEMCPY 1 if HAVE_MEMCPY is defined + HAVE_MMAP defined as 1 + MMAP_AS_MORECORE_SIZE (1024 * 1024) + HAVE_MREMAP defined as 0 unless linux defined + malloc_getpagesize derived from system #includes, or 4096 if not + HAVE_USR_INCLUDE_MALLOC_H NOT defined + LACKS_UNISTD_H NOT defined unless WIN32 + LACKS_SYS_PARAM_H NOT defined unless WIN32 + LACKS_SYS_MMAN_H NOT defined unless WIN32 + + Changing default word sizes: + + INTERNAL_SIZE_T size_t + MALLOC_ALIGNMENT 2 * sizeof(INTERNAL_SIZE_T) + + Configuration and functionality options: + + USE_DL_PREFIX NOT defined + USE_PUBLIC_MALLOC_WRAPPERS NOT defined + USE_MALLOC_LOCK NOT defined + DEBUG NOT defined + REALLOC_ZERO_BYTES_FREES NOT defined + MALLOC_FAILURE_ACTION errno = ENOMEM, if __STD_C defined, else no-op + TRIM_FASTBINS 0 + + Options for customizing MORECORE: + + MORECORE sbrk + MORECORE_CONTIGUOUS 1 + + Tuning options that are also dynamically changeable via mallopt: + + DEFAULT_MXFAST 64 + DEFAULT_TRIM_THRESHOLD 128 * 1024 + DEFAULT_TOP_PAD 0 + DEFAULT_MMAP_THRESHOLD 128 * 1024 + DEFAULT_MMAP_MAX 256 + + There are several other #defined constants and macros that you + probably don't want to touch unless you are extending or adapting malloc. + +*/ +#include "xpcom-private.h" + + + +/* + WIN32 sets up defaults for MS environment and compilers. + Otherwise defaults are for unix. +*/ + +/* #define WIN32 */ + +#ifdef WIN32 + +#include <windows.h> + +/* Win32 doesn't supply or need the following headers */ +#define LACKS_UNISTD_H +#define LACKS_SYS_PARAM_H +#define LACKS_SYS_MMAN_H + +/* Use the supplied emulation of sbrk */ +#define MORECORE sbrk +#define MORECORE_CONTIGUOUS 1 +#define MORECORE_FAILURE ((void*)(-1)) + +/* Use the supplied emulation mmap, munmap */ +#define HAVE_MMAP 1 +#define MUNMAP_FAILURE (-1) +/* These values don't really matter in windows mmap emulation */ +#define MAP_PRIVATE 1 +#define MAP_ANONYMOUS 2 +#define PROT_READ 1 +#define PROT_WRITE 2 + +/* Emulation functions defined at the end of this file */ + +/* If USE_MALLOC_LOCK, use supplied critical-section-based lock functions */ +#ifdef USE_MALLOC_LOCK +static int slwait(int *sl); +static int slrelease(int *sl); +#endif + +static long getpagesize(void); +static long getregionsize(void); +static void *sbrk(long size); +static void *mmap(void *ptr, long size, long prot, long type, long handle, long arg); +static long munmap(void *ptr, long size); + +static void vminfo (unsigned long *free, unsigned long *reserved, unsigned long *committed); +static int cpuinfo (int whole, unsigned long *kernel, unsigned long *user); + +#endif + + + +/* + __STD_C should be nonzero if using ANSI-standard C compiler, a C++ + compiler, or a C compiler sufficiently close to ANSI to get away + with it. +*/ + +#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*/ + + +/* + Void_t* is the pointer type that malloc should say it returns +*/ + +#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 + +/* define LACKS_UNISTD_H if your system does not have a <unistd.h>. */ + +/* #define LACKS_UNISTD_H */ + +#ifndef LACKS_UNISTD_H +#include <unistd.h> +#endif + +/* define LACKS_SYS_PARAM_H if your system does not have a <sys/param.h>. */ + +/* #define LACKS_SYS_PARAM_H */ + + +#include <stdio.h> /* needed for malloc_stats */ +#include <errno.h> /* needed for optional MALLOC_FAILURE_ACTION */ + + +/* + Debugging: + + Because freed chunks may be overwritten with bookkeeping 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. + + The default version is the same as size_t. + + While not strictly necessary, it is best to define this as an + unsigned type, even if size_t is a signed type. This may avoid some + artificial size limitations on some systems. + + On a 64-bit machine, you may be able to reduce malloc overhead by + defining INTERNAL_SIZE_T to be a 32 bit `unsigned int' at the + expense of not being able to handle more than 2^32 of malloced + space. If this limitation is acceptable, you are encouraged to set + this unless you are on a platform requiring 16byte alignments. In + this case the alignment requirements turn out to negate any + potential advantages of decreasing size_t word size. + + Note to implementors: To deal with all this, comparisons and + difference computations among INTERNAL_SIZE_Ts should normally cast + INTERNAL_SIZE_T's to long or unsigned long, as appropriate, being + aware of the fact that casting an unsigned int to a wider long does not + sign-extend. (This also makes checking for negative numbers awkward.) + +*/ + +#ifndef INTERNAL_SIZE_T +#define INTERNAL_SIZE_T size_t +#endif + +/* The corresponding word size */ +#define SIZE_SZ (sizeof(INTERNAL_SIZE_T)) + + +/* + MALLOC_ALIGNMENT is the minimum alignment for malloc'ed chunks. + It must be a power of two at least 2 * SIZE_SZ, even on machines + for which smaller alignments would suffice. It may be defined as + larger than this though. (Note however that code and data structures + are optimized for the case of 8-byte alignment.) + +*/ + + /* #define MALLOC_ALIGNMENT 16 */ + +#ifndef MALLOC_ALIGNMENT +#define MALLOC_ALIGNMENT (2 * SIZE_SZ) +#endif + +/* The corresponding bit mask value */ +#define MALLOC_ALIGN_MASK (MALLOC_ALIGNMENT - 1) + + +/* + REALLOC_ZERO_BYTES_FREES should be set if a call to + realloc with zero bytes should be the same as a call to free. + 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 */ + + +/* + USE_DL_PREFIX will prefix all public routines with the string 'dl'. + This is necessary when you only want to use this malloc in one part + of a program, using your regular system malloc elsewhere. +*/ + +/* #define USE_DL_PREFIX */ + + +/* + USE_MALLOC_LOCK causes wrapper functions to surround each + callable routine with pthread mutex lock/unlock. + + USE_MALLOC_LOCK forces USE_PUBLIC_MALLOC_WRAPPERS to be defined +*/ + +/* #define USE_MALLOC_LOCK */ + + +/* + If USE_PUBLIC_MALLOC_WRAPPERS is defined, every public routine is + actually a wrapper function that first calls MALLOC_PREACTION, then + calls the internal routine, and follows it with + MALLOC_POSTACTION. This is needed for locking, but you can also use + this, without USE_MALLOC_LOCK, for purposes of interception, + instrumentation, etc. It is a sad fact that using wrappers often + noticeably degrades performance of malloc-intensive programs. +*/ + +#ifdef USE_MALLOC_LOCK +#define USE_PUBLIC_MALLOC_WRAPPERS +#else +/* #define USE_PUBLIC_MALLOC_WRAPPERS */ +#endif + + + + +/* + HAVE_MEMCPY should be defined if you are not otherwise using + ANSI STD C, but still have memcpy and memset in your C library + and want to use them in calloc and realloc. Otherwise simple + macro versions are defined below. + + USE_MEMCPY should be defined as 1 if you actually want to + have memset and memcpy called. People report that the macro + versions are faster than libc versions on some systems. + + Even if USE_MEMCPY is set to 1, loops to copy/clear small chunks + (of <= 36 bytes) are manually unrolled in realloc and calloc. +*/ + +#define HAVE_MEMCPY + +#ifndef USE_MEMCPY +#ifdef HAVE_MEMCPY +#define USE_MEMCPY 1 +#else +#define USE_MEMCPY 0 +#endif +#endif + + +#if (__STD_C || defined(HAVE_MEMCPY)) + +#ifdef WIN32 + /* + On Win32 platforms, 'memset()' and 'memcpy()' are already declared in + 'windows.h' + */ +#else +#if __STD_C +void* memset(void*, int, size_t); +void* memcpy(void*, const void*, size_t); +void* memmove(void*, const void*, size_t); +#else +Void_t* memset(); +Void_t* memcpy(); +Void_t* memmove(); +#endif +#endif +#endif + + +/* + MALLOC_FAILURE_ACTION is the action to take before "return 0" when + malloc fails to be able to return memory, either because memory is + exhausted or because of illegal arguments. + + By default, sets errno if running on STD_C platform, else does nothing. +*/ + +#ifndef MALLOC_FAILURE_ACTION +#if __STD_C +#define MALLOC_FAILURE_ACTION \ + errno = ENOMEM; + +#else + +#define MALLOC_FAILURE_ACTION +#endif +#endif + +/* + Define HAVE_MMAP as true to optionally make malloc() use mmap() to + allocate very large blocks. These will be returned to the + operating system immediately after a free(). Also, if mmap + is available, it is used as a backup strategy in cases where + MORECORE fails to provide space from system. + + This malloc is best tuned to work with mmap for large requests. + If you do not have mmap, allocation of very large chunks (1MB + or so) may be slower than you'd like. +*/ + +#ifndef HAVE_MMAP +#define HAVE_MMAP 1 +#endif + +/* + MMAP_AS_MORECORE_SIZE is the minimum mmap size argument to use if + sbrk fails, and mmap is used as a backup (which is done only if + HAVE_MMAP). The value must be a multiple of page size. This + backup strategy generally applies only when systems have "holes" in + address space, so sbrk cannot perform contiguous expansion, but + there is still space available on system. On systems for which + this is known to be useful (i.e. most linux kernels), this occurs + only when programs allocate huge amounts of memory. Between this, + and the fact that mmap regions tend to be limited, the size should + be large, to avoid too many mmap calls and thus avoid running out + of kernel resources. +*/ + +#ifndef MMAP_AS_MORECORE_SIZE +#define MMAP_AS_MORECORE_SIZE (1024 * 1024) +#endif + + + +/* + Define HAVE_MREMAP to make realloc() use mremap() to re-allocate + large blocks. This is currently only possible on Linux with + kernel versions newer than 1.3.77. +*/ + +#ifndef HAVE_MREMAP +#ifdef linux +#define HAVE_MREMAP 1 +#else +#define HAVE_MREMAP 0 +#endif + +#endif /* HAVE_MMAP */ + + +/* + + This version of malloc supports the standard SVID/XPG mallinfo + routine that returns a struct containing usage properties and + statistics. 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 field that are not even meaningful in this version of + malloc. These fields are are instead filled by mallinfo() with + other numbers that might be of interest. + + HAVE_USR_INCLUDE_MALLOC_H should be set if you have a + /usr/include/malloc.h file that includes a declaration of struct + mallinfo. If so, it is included; else an SVID2/XPG2 compliant + version is declared below. These must be precisely the same for + mallinfo() to work. + +*/ + +/* #define HAVE_USR_INCLUDE_MALLOC_H */ + +#ifdef HAVE_USR_INCLUDE_MALLOC_H +#include "/usr/include/malloc.h" +#else + +/* SVID2/XPG mallinfo structure */ + +struct mallinfo { + int arena; /* non-mmapped space allocated from system */ + int ordblks; /* number of free chunks */ + int smblks; /* number of fastbin blocks */ + int hblks; /* number of mmapped regions */ + int hblkhd; /* space in mmapped regions */ + int usmblks; /* maximum total allocated space */ + int fsmblks; /* space available in freed fastbin blocks */ + int uordblks; /* total allocated space */ + int fordblks; /* total free space */ + int keepcost; /* top-most, releasable (via malloc_trim) space */ +}; + +/* SVID2/XPG mallopt options */ + +#define M_MXFAST 1 /* Set maximum fastbin size */ +#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 + + +/* Additional mallopt options supported in this malloc */ + +#ifndef M_TRIM_THRESHOLD +#define M_TRIM_THRESHOLD -1 +#endif + +#ifndef M_TOP_PAD +#define M_TOP_PAD -2 +#endif + +#ifndef M_MMAP_THRESHOLD +#define M_MMAP_THRESHOLD -3 +#endif + +#ifndef M_MMAP_MAX +#define M_MMAP_MAX -4 +#endif + + +/* + MXFAST is the maximum request size used for "fastbins", special bins + that hold returned chunks without consolidating their spaces. This + enables future requests for chunks of the same size to be handled + very quickly, but can increase fragmentation, and thus increase the + overall memory footprint of a program. + + This malloc manages fastbins very conservatively yet still + efficiently, so fragmentation is rarely a problem for values less + than or equal to the default. The maximum supported value of MXFAST + is 80. You wouldn't want it any higher than this anyway. Fastbins + are designed especially for use with many small structs, objects or + strings -- the default handles structs/objects/arrays with sizes up + to 8 4byte fields, or small strings representing words, tokens, + etc. Using fastbins for larger objects normally worsens + fragmentation without improving speed. + + MXFAST is set in REQUEST size units. It is internally used in + chunksize units, which adds padding and alignment. You can reduce + MXFAST to 0 to disable all use of fastbins. This causes the malloc + algorithm to be a close approximation of fifo-best-fit in all cases, + not just for larger requests, but will generally cause it to be + slower. + +*/ + +#ifndef DEFAULT_MXFAST +#define DEFAULT_MXFAST 64 +#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); + + Trim settings interact with fastbin (MXFAST) settings: Unless + TRIM_FASTBINS is defined, automatic trimming never takes place upon + freeing a chunk with size less than or equal to MXFAST. Trimming is + instead delayed until subsequent freeing of larger chunks. However, + you can still force an attempted trim by calling malloc_trim. + + Also, trimming is not generally possible in cases where + the main arena is obtained via mmap. + +*/ + + +#ifndef DEFAULT_TRIM_THRESHOLD +#define DEFAULT_TRIM_THRESHOLD (128 * 1024) +#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_TOP_PAD +#define DEFAULT_TOP_PAD (0) +#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 + means 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_THRESHOLD +#define DEFAULT_MMAP_THRESHOLD (128 * 1024) +#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. + + Setting to 0 disables use of mmap for servicing large requests. If + HAVE_MMAP is not set, the default value is 0, and attempts to set it + to non-zero values in mallopt will fail. +*/ + + + +#ifndef DEFAULT_MMAP_MAX +#if HAVE_MMAP +#define DEFAULT_MMAP_MAX (256) +#else +#define DEFAULT_MMAP_MAX (0) +#endif +#endif + + +/* + TRIM_FASTBINS controls whether free() of a very small chunk can + immediately lead to trimming. Setting to true (1) can reduce memory + footprint, but will almost always slow down (by a few percent) + programs that use a lot of small chunks. + + Define this only if you are willing to give up some speed to more + aggressively reduce system-level memory footprint when releasing + memory in programs that use many small chunks. You can get + essentially the same effect by setting MXFAST to 0, but this can + lead to even greater slowdowns in programs using many small chunks. + TRIM_FASTBINS is an in-between compile-time option, that disables + only those chunks bordering topmost memory from being placed in + fastbins. + +*/ + + +#ifndef TRIM_FASTBINS +#define TRIM_FASTBINS 0 +#endif + + +/* + MORECORE-related declarations. By default, rely on sbrk +*/ + + +#ifdef LACKS_UNISTD_H +#if !defined(__FreeBSD__) && !defined(__OpenBSD__) && !defined(__NetBSD__) +#if __STD_C +extern Void_t* sbrk(ptrdiff_t); +#else +extern Void_t* sbrk(); +#endif +#endif +#endif + +/* + MORECORE is the name of the routine to call to obtain more memory + from the system. See below for general guidance on writing + alternative MORECORE functions, as well as a version for WIN32 and a + sample version for pre-OSX macos. +*/ + +#ifndef MORECORE +#define MORECORE sbrk +#endif + + +/* + MORECORE_FAILURE is the value returned upon failure of MORECORE + as well as mmap. Since it cannot be an otherwise valid memory address, + and must reflect values of standard sys calls, you probably ought not + try to redefine it. +*/ + +#ifndef MORECORE_FAILURE +#define MORECORE_FAILURE (-1) +#endif + +/* + If MORECORE_CONTIGUOUS is true, take advantage of fact that + consecutive calls to MORECORE with positive arguments always return + contiguous increasing addresses. This is true of unix sbrk. Even + if not defined, when regions happen to be contiguous, malloc will + permit allocations spanning regions obtained from different + calls. But defining this when applicable enables some stronger + consistency checks and space efficiencies. +*/ + + +#ifndef MORECORE_CONTIGUOUS +#define MORECORE_CONTIGUOUS 1 +#endif + + +/* + The system page size. To the extent possible, this malloc manages + memory from the system in page-size units. Note that this value is + cached during initialization into a field of malloc_state. So even + if malloc_getpagesize is a function, it is only called once. + + The following mechanics for getpagesize were adapted from bsd/gnu + getpagesize.h. If none of the system-probes here apply, a value of + 4096 is used, which should be OK: If they don't apply, then using + the actual value probably doesn't impact performance. +*/ + +#ifndef malloc_getpagesize + +#ifndef LACKS_UNISTD_H +# include <unistd.h> +#endif + +# 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 /* use supplied emulation of getpagesize */ +# define malloc_getpagesize getpagesize() +# 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 /* just guess */ +# define malloc_getpagesize (4096) +# endif +# endif +# endif +# endif +# endif +# endif +# endif +#endif + + +/* Two-phase Name mangling */ + +#ifndef USE_PUBLIC_MALLOC_WRAPPERS +#define cALLOc public_cALLOc +#define fREe public_fREe +#define cFREe public_cFREe +#define mALLOc public_mALLOc +#define mEMALIGn public_mEMALIGn +#define rEALLOc public_rEALLOc +#define vALLOc public_vALLOc +#define pVALLOc public_pVALLOc +#define mALLINFo public_mALLINFo +#define mALLOPt public_mALLOPt +#define mTRIm public_mTRIm +#define mSTATs public_mSTATs +#define mUSABLe public_mUSABLe +#endif + +#ifdef USE_DL_PREFIX +#define public_cALLOc dlcalloc +#define public_fREe dlfree +#define public_cFREe dlcfree +#define public_mALLOc dlmalloc +#define public_mEMALIGn dlmemalign +#define public_rEALLOc dlrealloc +#define public_vALLOc dlvalloc +#define public_pVALLOc dlpvalloc +#define public_mALLINFo dlmallinfo +#define public_mALLOPt dlmallopt +#define public_mTRIm dlmalloc_trim +#define public_mSTATs dlmalloc_stats +#define public_mUSABLe dlmalloc_usable_size +#else /* USE_DL_PREFIX */ +#define public_cALLOc calloc +#define public_fREe free +#define public_cFREe cfree +#define public_mALLOc malloc +#define public_mEMALIGn memalign +#define public_rEALLOc realloc +#define public_vALLOc valloc +#define public_pVALLOc pvalloc +#define public_mALLINFo mallinfo +#define public_mALLOPt mallopt +#define public_mTRIm malloc_trim +#define public_mSTATs malloc_stats +#define public_mUSABLe malloc_usable_size +#endif /* USE_DL_PREFIX */ + +#if __STD_C + +Void_t* public_mALLOc(size_t); +void public_fREe(Void_t*); +Void_t* public_rEALLOc(Void_t*, size_t); +Void_t* public_mEMALIGn(size_t, size_t); +Void_t* public_vALLOc(size_t); +Void_t* public_pVALLOc(size_t); +Void_t* public_cALLOc(size_t, size_t); +void public_cFREe(Void_t*); +int public_mTRIm(size_t); +size_t public_mUSABLe(Void_t*); +void public_mSTATs(); +int public_mALLOPt(int, int); +struct mallinfo public_mALLINFo(void); +#else +Void_t* public_mALLOc(); +void public_fREe(); +Void_t* public_rEALLOc(); +Void_t* public_mEMALIGn(); +Void_t* public_vALLOc(); +Void_t* public_pVALLOc(); +Void_t* public_cALLOc(); +void public_cFREe(); +int public_mTRIm(); +size_t public_mUSABLe(); +void public_mSTATs(); +int public_mALLOPt(); +struct mallinfo public_mALLINFo(); +#endif + + +#ifdef __cplusplus +}; /* end of extern "C" */ +#endif + + + +/* ---------- To make a malloc.h, end cutting here ------------ */ + + +/* Declarations of internal utilities defined below */ + + + + +#ifdef USE_PUBLIC_MALLOC_WRAPPERS +#if __STD_C + +static Void_t* mALLOc(size_t); +static void fREe(Void_t*); +static Void_t* rEALLOc(Void_t*, size_t); +static Void_t* mEMALIGn(size_t, size_t); +static Void_t* vALLOc(size_t); +static Void_t* pVALLOc(size_t); +static Void_t* cALLOc(size_t, size_t); +static void cFREe(Void_t*); +static int mTRIm(size_t); +static size_t mUSABLe(Void_t*); +static void mSTATs(); +static int mALLOPt(int, int); +static struct mallinfo mALLINFo(void); +#else +static Void_t* mALLOc(); +static void fREe(); +static Void_t* rEALLOc(); +static Void_t* mEMALIGn(); +static Void_t* vALLOc(); +static Void_t* pVALLOc(); +static Void_t* cALLOc(); +static void cFREe(); +static int mTRIm(); +static size_t mUSABLe(); +static void mSTATs(); +static int mALLOPt(); +static struct mallinfo mALLINFo(); +#endif +#endif + + + +/* ---------- public wrappers --------------- */ + +#ifdef USE_PUBLIC_MALLOC_WRAPPERS + +/* + MALLOC_PREACTION and MALLOC_POSTACTION should be + defined to return 0 on success, and nonzero on failure. + The return value of MALLOC_POSTACTION is currently ignored + in wrapper functions since there is no reasonable default + action to take on failure. +*/ + + +#ifdef USE_MALLOC_LOCK + +#ifdef WIN32 + +static int mALLOC_MUTEx; + +#define MALLOC_PREACTION slwait(&mALLOC_MUTEx) +#define MALLOC_POSTACTION slrelease(&mALLOC_MUTEx) + +#else + +#include <pthread.h> + +static pthread_mutex_t mALLOC_MUTEx = PTHREAD_MUTEX_INITIALIZER; + +#define MALLOC_PREACTION pthread_mutex_lock(&mALLOC_MUTEx) +#define MALLOC_POSTACTION pthread_mutex_unlock(&mALLOC_MUTEx) + +#endif /* USE_MALLOC_LOCK */ + +#else + +/* Substitute anything you like for these */ + +#define MALLOC_PREACTION (0) +#define MALLOC_POSTACTION (0) + +#endif + +Void_t* public_mALLOc(size_t bytes) { + Void_t* m; + if (MALLOC_PREACTION != 0) { + return 0; + } + m = mALLOc(bytes); + if (MALLOC_POSTACTION != 0) { + } + return m; +} + +void public_fREe(Void_t* m) { + if (MALLOC_PREACTION != 0) { + return; + } + fREe(m); + if (MALLOC_POSTACTION != 0) { + } +} + +Void_t* public_rEALLOc(Void_t* m, size_t bytes) { + if (MALLOC_PREACTION != 0) { + return 0; + } + m = rEALLOc(m, bytes); + if (MALLOC_POSTACTION != 0) { + } + return m; +} + +Void_t* public_mEMALIGn(size_t alignment, size_t bytes) { + Void_t* m; + if (MALLOC_PREACTION != 0) { + return 0; + } + m = mEMALIGn(alignment, bytes); + if (MALLOC_POSTACTION != 0) { + } + return m; +} + +Void_t* public_vALLOc(size_t bytes) { + Void_t* m; + if (MALLOC_PREACTION != 0) { + return 0; + } + m = vALLOc(bytes); + if (MALLOC_POSTACTION != 0) { + } + return m; +} + +Void_t* public_pVALLOc(size_t bytes) { + Void_t* m; + if (MALLOC_PREACTION != 0) { + return 0; + } + m = pVALLOc(bytes); + if (MALLOC_POSTACTION != 0) { + } + return m; +} + +Void_t* public_cALLOc(size_t n, size_t elem_size) { + Void_t* m; + if (MALLOC_PREACTION != 0) { + return 0; + } + m = cALLOc(n, elem_size); + if (MALLOC_POSTACTION != 0) { + } + return m; +} + +void public_cFREe(Void_t* m) { + if (MALLOC_PREACTION != 0) { + return; + } + cFREe(m); + if (MALLOC_POSTACTION != 0) { + } +} + +int public_mTRIm(size_t s) { + int result; + if (MALLOC_PREACTION != 0) { + return 0; + } + result = mTRIm(s); + if (MALLOC_POSTACTION != 0) { + } + return result; +} + + +size_t public_mUSABLe(Void_t* m) { + size_t result; + if (MALLOC_PREACTION != 0) { + return 0; + } + result = mUSABLe(m); + if (MALLOC_POSTACTION != 0) { + } + return result; +} + + +void public_mSTATs() { + if (MALLOC_PREACTION != 0) { + return; + } + mSTATs(); + if (MALLOC_POSTACTION != 0) { + } +} + +struct mallinfo public_mALLINFo() { + struct mallinfo m; + if (MALLOC_PREACTION != 0) { + return m; + } + m = mALLINFo(); + if (MALLOC_POSTACTION != 0) { + } + return m; +} + +int public_mALLOPt(int p, int v) { + int result; + if (MALLOC_PREACTION != 0) { + return 0; + } + result = mALLOPt(p, v); + if (MALLOC_POSTACTION != 0) { + } + return result; +} + +#endif + + + +/* ------------- Optional versions of memcopy ---------------- */ + + +#if USE_MEMCPY + +#define MALLOC_COPY(dest, src, nbytes, overlap) \ + ((overlap) ? memmove(dest, src, nbytes) : memcpy(dest, src, nbytes)) +#define MALLOC_ZERO(dest, nbytes) memset(dest, 0, nbytes) + +#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) + +/* For overlapping case, dest is always _below_ src. */ + +#define MALLOC_COPY(dest,src,nbytes,overlap) \ +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 + +/* ------------------ MMAP support ------------------ */ + + +#if HAVE_MMAP + +#include <fcntl.h> +#ifndef LACKS_SYS_MMAN_H +#include <sys/mman.h> +#endif + +#if !defined(MAP_ANONYMOUS) && defined(MAP_ANON) +#define MAP_ANONYMOUS MAP_ANON +#endif + + +/* + Nearly all versions of mmap support MAP_ANONYMOUS, + so the following is unlikely to be needed, but is + supplied just in case. +*/ + +#ifndef MAP_ANONYMOUS + +static int dev_zero_fd = -1; /* Cached file descriptor for /dev/zero. */ + +#define MMAP(addr, size, prot, flags) ((dev_zero_fd < 0) ? \ + (dev_zero_fd = open("/dev/zero", O_RDWR), \ + mmap((addr), (size), (prot), (flags), dev_zero_fd, 0)) : \ + mmap((addr), (size), (prot), (flags), dev_zero_fd, 0)) + +#else + +#define MMAP(addr, size, prot, flags) \ + (mmap((addr), (size), (prot), (flags)|MAP_ANONYMOUS, -1, 0)) + +#endif + +#endif /* HAVE_MMAP */ + + +/* ---------- Alternative MORECORE functions ------------ */ + + +/* + General Requirements for MORECORE. + + The MORECORE function must have the following properties: + + If MORECORE_CONTIGUOUS is false: + + * MORECORE must allocate in multiples of pagesize. It will + only be called with arguments that are multiples of pagesize. + + * MORECORE must page-align. That is, MORECORE(0) must + return an address at a page boundary. + + else (i.e. If MORECORE_CONTIGUOUS is true): + + * Consecutive calls to MORECORE with positive arguments + return increasing addresses, indicating that space has been + contiguously extended. + + * MORECORE need not allocate in multiples of pagesize. + Calls to MORECORE need not have args of multiples of pagesize. + + * MORECORE need not page-align. + + In either case: + + * MORECORE may allocate more memory than requested. (Or even less, + but this will generally result in a malloc failure.) + + * MORECORE must not allocate memory when given argument zero, but + instead return one past the end address of memory from previous + nonzero call. This malloc does NOT call MORECORE(0) + until at least one call with positive arguments is made, so + the initial value returned is not important. + + * Even though consecutive calls to MORECORE need not return contiguous + addresses, it must be OK for malloc'ed chunks to span multiple + regions in those cases where they do happen to be contiguous. + + * MORECORE need not handle negative arguments -- it may instead + just return MORECORE_FAILURE when given negative arguments. + Negative arguments are always multiples of pagesize. MORECORE + must not misinterpret negative args as large positive unsigned + args. + + There is some variation across systems about the type of the + argument to sbrk/MORECORE. If size_t is unsigned, then it cannot + actually be size_t, because sbrk supports negative args, so it is + normally the signed type of the same width as size_t (sometimes + declared as "intptr_t", and sometimes "ptrdiff_t"). It doesn't much + matter though. Internally, we use "long" as arguments, which should + work across all reasonable possibilities. + + Additionally, if MORECORE ever returns failure for a positive + request, and HAVE_MMAP is true, then mmap is used as a noncontiguous + system allocator. This is a useful backup strategy for systems with + holes in address spaces -- in this case sbrk cannot contiguously + expand the heap, but mmap may be able to map noncontiguous space. + If you'd like mmap to ALWAYS be used, you can define MORECORE to be + a function that always returns MORECORE_FAILURE. + + If you are using this malloc with something other than unix sbrk to + supply memory regions, you probably want to set MORECORE_CONTIGUOUS + as false. As an example, here is a custom allocator kindly + contributed for pre-OSX macOS. It uses virtually but not + necessarily physically contiguous non-paged memory (locked in, + present and won't get swapped out). You can use it by uncommenting + this section, adding some #includes, and setting up the appropriate + defines above: + + #define MORECORE osMoreCore + #define MORECORE_CONTIGUOUS 0 + + There is also a shutdown routine that should somehow be called for + cleanup upon program exit. + + #define MAX_POOL_ENTRIES 100 + #define MINIMUM_MORECORE_SIZE (64 * 1024) + static int next_os_pool; + void *our_os_pools[MAX_POOL_ENTRIES]; + + void *osMoreCore(int size) + { + void *ptr = 0; + static void *sbrk_top = 0; + + if (size > 0) + { + if (size < MINIMUM_MORECORE_SIZE) + size = MINIMUM_MORECORE_SIZE; + if (CurrentExecutionLevel() == kTaskLevel) + ptr = PoolAllocateResident(size + RM_PAGE_SIZE, 0); + if (ptr == 0) + { + return (void *) MORECORE_FAILURE; + } + // save ptrs so they can be freed during cleanup + our_os_pools[next_os_pool] = ptr; + next_os_pool++; + ptr = (void *) ((((unsigned long) ptr) + RM_PAGE_MASK) & ~RM_PAGE_MASK); + sbrk_top = (char *) ptr + size; + return ptr; + } + else if (size < 0) + { + // we don't currently support shrink behavior + return (void *) MORECORE_FAILURE; + } + else + { + return sbrk_top; + } + } + + // cleanup any allocated memory pools + // called as last thing before shutting down driver + + void osCleanupMem(void) + { + void **ptr; + + for (ptr = our_os_pools; ptr < &our_os_pools[MAX_POOL_ENTRIES]; ptr++) + if (*ptr) + { + PoolDeallocate(*ptr); + *ptr = 0; + } + } + +*/ + + + + + +/* + ----------------------- Chunk representations ----------------------- +*/ + + +/* + This struct declaration is misleading (but accurate and necessary). + It declares a "view" into memory allowing access to necessary + fields at known offsets from a given base. See explanation below. +*/ + +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. If + prev_inuse is set for any given chunk, then you CANNOT determine + the size of the previous chunk, and might even get a memory + addressing fault when trying to do so. + + 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' 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. + + 2. Chunks allocated via mmap, which have the second-lowest-order + bit (IS_MMAPPED) set in their size fields. Because they are + allocated one-by-one, each must contain its own trailing size field. + +*/ + + + +/* + Size and alignment checks and conversions +*/ + +/* 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)) + +/* The smallest possible chunk */ +#define MIN_CHUNK_SIZE (sizeof(struct malloc_chunk)) + +/* The smallest size we can malloc is an aligned minimal chunk */ + +#define MINSIZE ((MIN_CHUNK_SIZE+MALLOC_ALIGN_MASK) & ~MALLOC_ALIGN_MASK) + +/* Check if m has acceptable alignment */ + +#define aligned_OK(m) (((unsigned long)((m)) & (MALLOC_ALIGN_MASK)) == 0) + +/* + Check for negative/huge sizes. + This cannot just test for < 0 because argument might + be an unsigned type of uncertain width. +*/ + +#define IS_NEGATIVE(x) \ + ((unsigned long)x >= \ + (unsigned long)((((INTERNAL_SIZE_T)(1)) << ((SIZE_SZ)*8 - 1)))) + + +/* pad request bytes into a usable size -- internal version */ + +#define request2size(req) \ + (((req) + SIZE_SZ + MALLOC_ALIGN_MASK < MINSIZE) ? \ + MINSIZE : \ + ((req) + SIZE_SZ + MALLOC_ALIGN_MASK) & ~MALLOC_ALIGN_MASK) + + +/* + Same, except check for negative/huge arguments. + This lets through args that are positive but wrap into + negatives when padded. However, these are trapped + elsewhere. +*/ + +#define checked_request2size(req, sz) \ + if (IS_NEGATIVE(req)) { \ + MALLOC_FAILURE_ACTION; \ + return 0; \ + } \ + (sz) = request2size(req); + + + + +/* + 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 + + Note: IS_MMAPPED is intentionally not masked off from size field in + macros for which mmapped chunks should never be seen. This should + cause helpful core dumps to occur if it is tried by accident by + people extending or adapting this malloc. + +*/ + + +/* 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 being inuse 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 field */ + +#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)) + + + + + +/* + ------------------ Internal data structures -------------------- + + All internal state is held in an instance of malloc_state defined + below. There are no other static variables, except in two optional + cases: + * If USE_MALLOC_LOCK is defined, the mALLOC_MUTEx declared + above. + * If HAVE_MMAP is true, but mmap doesn't support + MAP_ANONYMOUS, a dummy file descriptor for mmap. + + Beware of lots of tricks that minimize the total space + requirements. The result is a little over 1K bytes (for 4byte + pointers and size_t.) + +*/ + +/* + + Bins + + An array of bin headers for free 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. Most bins hold sizes that are + unusual as malloc request sizes, but are more usual for fragments + and consolidated sets of chunks, which is what these bins hold, so + they can be found quickly. All procedures maintain the invariant + that no consolidated chunk physically borders another one, so each + chunk in a list is known to be preceeded and followed by either + inuse chunks or the ends of memory. + + Chunks in bins are kept in size order, with ties going to the + approximately least recently used chunk. Ordering 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 (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. + + To simplify use in double-linked lists, each bin header acts + as a malloc_chunk. This avoids special-casing for headers. + But to conserve space and (mainly) improve locality, we allocate + only the fd/bk pointers of bins, and then use repositioning tricks + to treat these as the fields of a malloc_chunk*. +*/ + +typedef struct malloc_chunk* mbinptr; + +#define NBINS 128 + + +/* addressing -- note that bin_at(0) does not exist */ + +#define bin_at(m, i) ((mbinptr)((char*)&((m)->bins[(i)<<1]) - (SIZE_SZ<<1))) + + +/* analog of ++bin */ + +#define next_bin(b) ((mbinptr)((char*)(b) + (sizeof(mchunkptr)<<1))) + + +/* Reminders about list directionality within bins */ + +#define first(b) ((b)->fd) +#define last(b) ((b)->bk) + +/* + Take a chunk off a bin list +*/ + +#define unlink(P, BK, FD) { \ + FD = P->fd; \ + BK = P->bk; \ + FD->bk = BK; \ + BK->fd = FD; \ +} + +/* + Indexing bins + + Bins for sizes < 512 bytes contain chunks of all the same size, spaced + 8 bytes apart. Larger bins are approximately logarithmically spaced: + + 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 bins top out at around 1mb because we expect to service large + chunks via mmap. + +*/ + +/* The first NSMALLBIN bins (and fastbins) hold only one size */ +#define NSMALLBINS 64 +#define SMALLBIN_WIDTH 8 +#define MIN_LARGE_SIZE 512 + +#define in_smallbin_range(sz) ((sz) < MIN_LARGE_SIZE) + +#define smallbin_index(sz) (((unsigned)(sz)) >> 3) + +#define largebin_index(sz) \ +(((((unsigned long)(sz)) >> 6) <= 32)? 56 + (((unsigned long)(sz)) >> 6): \ + ((((unsigned long)(sz)) >> 9) <= 20)? 91 + (((unsigned long)(sz)) >> 9): \ + ((((unsigned long)(sz)) >> 12) <= 10)? 110 + (((unsigned long)(sz)) >> 12): \ + ((((unsigned long)(sz)) >> 15) <= 4)? 119 + (((unsigned long)(sz)) >> 15): \ + ((((unsigned long)(sz)) >> 18) <= 2)? 124 + (((unsigned long)(sz)) >> 18): \ + 126) + +#define bin_index(sz) \ + ((in_smallbin_range(sz)) ? smallbin_index(sz) : largebin_index(sz)) + + +/* + Unsorted chunks + + All remainders from chunk splits, as well as all returned chunks, + are first placed in the "unsorted" bin. They are then placed + in regular bins after malloc gives them ONE chance to be used before + binning. So, basically, the unsorted_chunks list acts as a queue, + with chunks being placed on it in free (and malloc_consolidate), + and taken off (to be either used or placed in bins) in malloc. + +*/ + + +/* The otherwise unindexable 1-bin is used to hold unsorted chunks. */ + +#define unsorted_chunks(M) (bin_at(M, 1)) + + +/* + 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). `top' is never properly linked to its bin + since it is always handled specially. 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 do so when getting memory from system, so we make + initial_top treat the bin as a legal but unusable chunk during the + interval between initialization and the first call to + sYSMALLOc. (This is somewhat delicate, since it relies on + the 2 preceding words to be zero during this interval as well.) +*/ + + +/* Conveniently, the unsorted bin can be used as dummy top on first call */ +#define initial_top(M) (unsorted_chunks(M)) + +/* + Binmap + + To help compensate for the large number of bins, a one-level index + structure is used for bin-by-bin searching. `binmap' is a + bitvector recording whether bins are definitely empty so they can + be skipped over during during traversals. The bits are NOT always + cleared as soon as bins are empty, but instead only + when they are noticed to be empty during traversal in malloc. + +*/ + +/* Conservatively use 32 bits per map word, even if on 64bit system */ +#define BINMAPSHIFT 5 +#define BITSPERMAP (1U << BINMAPSHIFT) +#define BINMAPSIZE (NBINS / BITSPERMAP) + +#define idx2block(i) ((i) >> BINMAPSHIFT) +#define idx2bit(i) ((1U << ((i) & ((1U << BINMAPSHIFT)-1)))) + +#define mark_bin(m,i) ((m)->binmap[idx2block(i)] |= idx2bit(i)) +#define unmark_bin(m,i) ((m)->binmap[idx2block(i)] &= ~(idx2bit(i))) +#define get_binmap(m,i) ((m)->binmap[idx2block(i)] & idx2bit(i)) + + +/* + Fastbins + + An array of lists holding recently freed small chunks. Fastbins + are not doubly linked. It is faster to single-link them, and + since chunks are never removed from the middles of these lists, + double linking is not necessary. + + Chunks in fastbins keep their inuse bit set, so they cannot + be consolidated with other free chunks. malloc_consolidate + releases all chunks in fastbins and consolidates them with + other free chunks. +*/ + +typedef struct malloc_chunk* mfastbinptr; + +/* offset 2 to use otherwise unindexable first 2 bins */ +#define fastbin_index(sz) ((((unsigned int)(sz)) >> 3) - 2) + +/* The maximum fastbin request size we support */ +#define MAX_FAST_SIZE 80 + +#define NFASTBINS (fastbin_index(request2size(MAX_FAST_SIZE))+1) + + + +/* + Flag bit held in max_fast indicating that there probably are some + fastbin chunks . It is set true on entering a chunk into any fastbin, + and cleared only in malloc_consolidate. + + The truth value is inverted so that have_fastchunks will be true + upon startup (since statics are zero-filled). +*/ + + +#define have_fastchunks(M) (((M)->max_fast & 1U) == 0) +#define clear_fastchunks(M) ((M)->max_fast |= 1U) +#define set_fastchunks(M) ((M)->max_fast &= ~1U) + +/* + Initialization value of max_fast. + Use impossibly small value if 0. + Value also has flag bit clear. +*/ +#define req2max_fast(s) (((((s) == 0)? SMALLBIN_WIDTH: request2size(s))) | 1U) + + +/* + NONCONTIGUOUS_REGIONS is a special value for sbrk_base indicating that + MORECORE does not return contiguous regions. In this case, we do not check + or assume that the address of each chunk is at least sbrk_base. Otherwise, + contiguity is exploited in merging together, when possible, results + from consecutive MORECORE calls. + + The possible values for sbrk_base are: + MORECORE_FAILURE: + MORECORE has not yet been called, but we expect contiguous space + NONCONTIGUOUS_REGIONS: + we don't expect or rely on contiguous space + any other legal address: + the first address returned by MORECORE when contiguous +*/ + +#define NONCONTIGUOUS_REGIONS ((char*)(-3)) + + +/* + ----------- Internal state representation and initialization ----------- +*/ + + +struct malloc_state { + + /* The maximum chunk size to be eligible for fastbin */ + INTERNAL_SIZE_T max_fast; /* low bit used as fastbin flag */ + + /* Base of the topmost chunk -- not otherwise kept in a bin */ + mchunkptr top; + + /* The remainder from the most recent split of a small request */ + mchunkptr last_remainder; + + /* Fastbins */ + mfastbinptr fastbins[NFASTBINS]; + + /* Normal bins packed as described above */ + mchunkptr bins[NBINS * 2]; + + /* Bitmap of bins */ + unsigned int binmap[BINMAPSIZE]; + + /* Tunable parameters */ + unsigned long trim_threshold; + INTERNAL_SIZE_T top_pad; + INTERNAL_SIZE_T mmap_threshold; + + /* Memory map support */ + int n_mmaps; + int n_mmaps_max; + int max_n_mmaps; + + /* Bookkeeping for sbrk */ + unsigned int pagesize; /* Cache malloc_getpagesize */ + char* sbrk_base; /* first address returned by sbrk, + or NONCONTIGUOUS_REGIONS */ + /* Statistics */ + + INTERNAL_SIZE_T mmapped_mem; + INTERNAL_SIZE_T sbrked_mem; + + INTERNAL_SIZE_T max_sbrked_mem; + INTERNAL_SIZE_T max_mmapped_mem; + INTERNAL_SIZE_T max_total_mem; +}; + +typedef struct malloc_state *mstate; + +/* + There is exactly one instance of this struct in this malloc. + + If you are adapting this malloc in a way that does NOT use a static + malloc_state, you MUST explicitly zero-fill it before using. This + malloc relies on the property that malloc_state is initialized to + all zeroes (as is true of C statics). + +*/ + +static struct malloc_state av_; /* never directly referenced */ + +/* + All uses of av_ are via get_malloc_state(). + This simplifies construction of multithreaded, etc extensions. + + At most one call to get_malloc_state is made per invocation of + the public versions of malloc, free, and all other routines + except realloc, valloc, and vpalloc. Also, it is called + in check* routines if DEBUG is set. +*/ + +#define get_malloc_state() (&(av_)) + +/* + Initialize a malloc_state struct. + + This is called only from within malloc_consolidate, which needs + be called in the same contexts anyway. It is never called directly + outside of malloc_consolidate because some optimizing compilers try + to inline it at all call points, which turns out not to be an + optimization at all. (Inlining it only in malloc_consolidate is fine though.) +*/ + +#if __STD_C +static void malloc_init_state(mstate av) +#else +static void malloc_init_state(av) mstate av; +#endif +{ + int i; + mbinptr bin; + + + /* Uncomment this if you are not using a static av */ + /* MALLOC_ZERO(av, sizeof(struct malloc_state); */ + + /* Establish circular links for normal bins */ + for (i = 1; i < NBINS; ++i) { + bin = bin_at(av,i); + bin->fd = bin->bk = bin; + } + + av->max_fast = req2max_fast(DEFAULT_MXFAST); + + av->top_pad = DEFAULT_TOP_PAD; + av->n_mmaps_max = DEFAULT_MMAP_MAX; + av->mmap_threshold = DEFAULT_MMAP_THRESHOLD; + +#if MORECORE_CONTIGUOUS + av->trim_threshold = DEFAULT_TRIM_THRESHOLD; + av->sbrk_base = (char*)MORECORE_FAILURE; +#else + av->trim_threshold = (unsigned long)(-1); + av->sbrk_base = NONCONTIGUOUS_REGIONS; +#endif + + av->top = initial_top(av); + av->pagesize = malloc_getpagesize; +} + +/* + Other internal utilities operating on mstates +*/ + +#if __STD_C +static Void_t* sYSMALLOc(INTERNAL_SIZE_T, mstate); +static int sYSTRIm(size_t, mstate); +static void malloc_consolidate(mstate); +#else +static Void_t* sYSMALLOc(); +static int sYSTRIm(); +static void malloc_consolidate(); +#endif + + +/* + Debugging support + + 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 ! DEBUG + +#define check_chunk(P) +#define check_free_chunk(P) +#define check_inuse_chunk(P) +#define check_remalloced_chunk(P,N) +#define check_malloced_chunk(P,N) +#define check_malloc_state() + +#else +#define check_chunk(P) do_check_chunk(P) +#define check_free_chunk(P) do_check_free_chunk(P) +#define check_inuse_chunk(P) do_check_inuse_chunk(P) +#define check_remalloced_chunk(P,N) do_check_remalloced_chunk(P,N) +#define check_malloced_chunk(P,N) do_check_malloced_chunk(P,N) +#define check_malloc_state() do_check_malloc_state() + + +/* + Properties of all chunks +*/ + +#if __STD_C +static void do_check_chunk(mchunkptr p) +#else +static void do_check_chunk(p) mchunkptr p; +#endif +{ + + mstate av = get_malloc_state(); + unsigned long sz = chunksize(p); + + if (!chunk_is_mmapped(p)) { + + /* Has legal address ... */ + if (av->sbrk_base != NONCONTIGUOUS_REGIONS) { + assert(((char*)p) >= ((char*)(av->sbrk_base))); + } + + if (p != av->top) { + if (av->sbrk_base != NONCONTIGUOUS_REGIONS) { + assert(((char*)p + sz) <= ((char*)(av->top))); + } + } + else { + if (av->sbrk_base != NONCONTIGUOUS_REGIONS) { + assert(((char*)p + sz) <= ((char*)(av->sbrk_base) + av->sbrked_mem)); + } + /* top size is always at least MINSIZE */ + assert((long)(sz) >= (long)(MINSIZE)); + /* top predecessor always marked inuse */ + assert(prev_inuse(p)); + } + + } + else { +#if HAVE_MMAP + /* address is outside main heap */ + /* unless mmap has been used as sbrk backup */ + if (av->sbrk_base != NONCONTIGUOUS_REGIONS) { + assert(! (((char*)p) >= ((char*)av->sbrk_base) && + ((char*)p) < ((char*)(av->sbrk_base) + av->sbrked_mem))); + } + /* chunk is page-aligned */ + assert(((p->prev_size + sz) & (av->pagesize-1)) == 0); + /* mem is aligned */ + assert(aligned_OK(chunk2mem(p))); +#else + /* force an appropriate assert violation if debug set */ + assert(!chunk_is_mmapped(p)); +#endif + } + +} + +/* + Properties of free chunks +*/ + + +#if __STD_C +static void do_check_free_chunk(mchunkptr p) +#else +static void do_check_free_chunk(p) mchunkptr p; +#endif +{ + mstate av = get_malloc_state(); + + INTERNAL_SIZE_T sz = p->size & ~PREV_INUSE; + mchunkptr next = chunk_at_offset(p, sz); + + do_check_chunk(p); + + /* Chunk must claim to be free ... */ + assert(!inuse(p)); + assert (!chunk_is_mmapped(p)); + + /* Unless a special marker, must have OK fields */ + if ((unsigned long)sz >= (unsigned 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 == av->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); +} + +/* + Properties of inuse chunks +*/ + + +#if __STD_C +static void do_check_inuse_chunk(mchunkptr p) +#else +static void do_check_inuse_chunk(p) mchunkptr p; +#endif +{ + mstate av = get_malloc_state(); + mchunkptr next; + do_check_chunk(p); + + if (chunk_is_mmapped(p)) + return; /* mmapped chunks have no next/prev */ + + /* Check whether it claims to be in use ... */ + assert(inuse(p)); + + next = next_chunk(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)) { + /* Note that we cannot even look at prev unless it is not inuse */ + mchunkptr prv = prev_chunk(p); + assert(next_chunk(prv) == p); + do_check_free_chunk(prv); + } + + if (next == av->top) { + assert(prev_inuse(next)); + assert(chunksize(next) >= MINSIZE); + } + else if (!inuse(next)) + do_check_free_chunk(next); + +} + +/* + Properties of chunks recycled from fastbins +*/ + +#if __STD_C +static void do_check_remalloced_chunk(mchunkptr p, INTERNAL_SIZE_T s) +#else +static void do_check_remalloced_chunk(p, s) mchunkptr p; INTERNAL_SIZE_T s; +#endif +{ + + INTERNAL_SIZE_T sz = p->size & ~PREV_INUSE; + + do_check_inuse_chunk(p); + + /* Legal size ... */ + assert((sz & MALLOC_ALIGN_MASK) == 0); + assert((long)sz - (long)MINSIZE >= 0); + assert((long)sz - (long)s >= 0); + assert((long)sz - (long)(s + MINSIZE) < 0); + + /* ... and alignment */ + assert(aligned_OK(chunk2mem(p))); + +} + +/* + Properties of nonrecycled chunks at the point they are malloced +*/ + +#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 +{ + /* same as recycled case ... */ + do_check_remalloced_chunk(p, s); + + /* + ... plus, must obey implementation invariant 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. This is ensured + by making all allocations from the the `lowest' part of any found + chunk. This does not necessarily hold however for chunks + recycled via fastbins. + */ + + assert(prev_inuse(p)); +} + + +/* + Properties of malloc_state. + + This may be useful for debugging malloc, as well as detecting user + programmer errors that somehow write into malloc_state. +*/ + +static void do_check_malloc_state() +{ + mstate av = get_malloc_state(); + int i; + mchunkptr p; + mchunkptr q; + mbinptr b; + unsigned int biton; + int empty; + unsigned int idx; + INTERNAL_SIZE_T size; + unsigned long total = 0; + int max_fast_bin; + + + /* internal size_t must be no wider than pointer type */ + assert(sizeof(INTERNAL_SIZE_T) <= sizeof(char*)); + + /* alignment is a power of 2 */ + assert((MALLOC_ALIGNMENT & (MALLOC_ALIGNMENT-1)) == 0); + + /* cannot run remaining checks until fully initialized */ + if (av->top == 0 || av->top == initial_top(av)) + return; + + /* pagesize is a power of 2 */ + assert((av->pagesize & (av->pagesize-1)) == 0); + + /* properties of fastbins */ + + /* max_fast is in allowed range */ + + assert((av->max_fast & ~1) <= request2size(MAX_FAST_SIZE)); + + max_fast_bin = fastbin_index(av->max_fast); + + for (i = 0; i < NFASTBINS; ++i) { + p = av->fastbins[i]; + + /* all bins past max_fast are empty */ + if (i > max_fast_bin) + assert(p == 0); + + while (p != 0) { + /* each chunk claims to be inuse */ + do_check_inuse_chunk(p); + total += chunksize(p); + /* chunk belongs in this bin */ + assert(fastbin_index(chunksize(p)) == i); + p = p->fd; + } + } + + if (total != 0) + assert(have_fastchunks(av)); + + /* check normal bins */ + for (i = 1; i < NBINS; ++i) { + b = bin_at(av,i); + + /* binmap is accurate (except for bin 1 == unsorted_chunks) */ + if (i >= 2) { + biton = get_binmap(av,i); + empty = last(b) == b; + if (!biton) + assert(empty); + else if (!empty) + assert(biton); + } + + for (p = last(b); p != b; p = p->bk) { + /* each chunk claims to be free */ + do_check_free_chunk(p); + size = chunksize(p); + total += size; + if (i >= 2) { + /* chunk belongs in bin */ + idx = bin_index(size); + assert(idx == i); + /* lists are sorted */ + assert(p->bk == b || chunksize(p->bk) >= chunksize(p)); + } + /* chunk is followed by a legal chain of inuse chunks */ + for (q = next_chunk(p); + q != av->top && inuse(q) && (long)(chunksize(q)) >= (long)MINSIZE; + q = next_chunk(q)) + do_check_inuse_chunk(q); + + } + } + + /* top chunk is OK */ + check_chunk(av->top); + + /* sanity checks for statistics */ + + assert(total <= (unsigned long)(av->max_total_mem)); + assert(av->n_mmaps >= 0); + assert(av->n_mmaps <= av->n_mmaps_max); + assert(av->n_mmaps <= av->max_n_mmaps); + assert(av->max_n_mmaps <= av->n_mmaps_max); + + assert((unsigned long)(av->sbrked_mem) <= + (unsigned long)(av->max_sbrked_mem)); + + assert((unsigned long)(av->mmapped_mem) <= + (unsigned long)(av->max_mmapped_mem)); + + assert((unsigned long)(av->max_total_mem) >= + (unsigned long)(av->mmapped_mem) + (unsigned long)(av->sbrked_mem)); + +} + + +#endif + + + + + +/* ----------- Routines dealing with system allocation -------------- */ + +/* + Handle malloc cases requiring more memory from system. + malloc relays to sYSMALLOc if it cannot allocate out of + existing memory. + + On entry, it is assumed that av->top does not have enough + space to service request for nb bytes, thus requiring more meory + from system. +*/ + +#if __STD_C +static Void_t* sYSMALLOc(INTERNAL_SIZE_T nb, mstate av) +#else +static Void_t* sYSMALLOc(nb, av) INTERNAL_SIZE_T nb; mstate av; +#endif +{ + mchunkptr old_top; /* incoming value of av->top */ + INTERNAL_SIZE_T old_size; /* its size */ + char* old_end; /* its end address */ + + long size; /* arg to first MORECORE or mmap call */ + char* brk; /* return value from MORECORE */ + char* mm; /* return value from mmap call*/ + + long correction; /* arg to 2nd MORECORE call */ + char* snd_brk; /* 2nd return val */ + + INTERNAL_SIZE_T front_misalign; /* unusable bytes at front of new space */ + INTERNAL_SIZE_T end_misalign; /* partial page left at end of new space */ + char* aligned_brk; /* aligned offset into brk */ + + mchunkptr p; /* the allocated/returned chunk */ + mchunkptr remainder; /* remainder from allocation */ + long remainder_size; /* its size */ + + unsigned long sum; /* for updating stats */ + + size_t pagemask = av->pagesize - 1; + + /* + If have mmap, and 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, try to + directly map this request rather than expanding top. + */ + +#if HAVE_MMAP + if ((unsigned long)nb >= (unsigned long)(av->mmap_threshold) && + (av->n_mmaps < av->n_mmaps_max)) { + + /* + Round up size to nearest page. For mmapped chunks, the overhead + is one SIZE_SZ unit larger than for normal chunks, because there + is no following chunk whose prev_size field could be used. + */ + size = (nb + SIZE_SZ + MALLOC_ALIGN_MASK + pagemask) & ~pagemask; + + mm = (char*)(MMAP(0, size, PROT_READ|PROT_WRITE, MAP_PRIVATE)); + + if (mm != (char*)(MORECORE_FAILURE)) { + + /* + The offset to the start of the mmapped region is stored + in the prev_size field of the chunk. This allows us to adjust + returned start address to meet alignment requirements here + and in memalign(), and still be able to compute proper + address argument for later munmap in free() and realloc(). + */ + + front_misalign = (INTERNAL_SIZE_T)chunk2mem(mm) & MALLOC_ALIGN_MASK; + if (front_misalign > 0) { + correction = MALLOC_ALIGNMENT - front_misalign; + p = (mchunkptr)(mm + correction); + p->prev_size = correction; + set_head(p, (size - correction) |IS_MMAPPED); + } + else { + p = (mchunkptr)mm; + set_head(p, size|IS_MMAPPED); + } + + check_chunk(p); + + /* update statistics */ + + if (++av->n_mmaps > av->max_n_mmaps) + av->max_n_mmaps = av->n_mmaps; + + sum = av->mmapped_mem += size; + if (sum > (unsigned long)(av->max_mmapped_mem)) + av->max_mmapped_mem = sum; + sum += av->sbrked_mem; + if (sum > (unsigned long)(av->max_total_mem)) + av->max_total_mem = sum; + + return chunk2mem(p); + } + } +#endif + + /* record incoming configuration of top */ + + old_top = av->top; + old_size = chunksize(old_top); + old_end = (char*)(chunk_at_offset(old_top, old_size)); + + brk = snd_brk = (char*)(MORECORE_FAILURE); + + /* + If not the first time through, we require old_size to be + at least MINSIZE and to have prev_inuse set. + */ + + assert(old_top == initial_top(av) || + ((unsigned long) (old_size) >= (unsigned long)(MINSIZE) && + prev_inuse(old_top))); + + + /* Request enough space for nb + pad + overhead */ + + size = nb + av->top_pad + MINSIZE; + + /* + If contiguous, we can subtract out existing space that we hope to + combine with new space. We add it back later only if + we don't actually get contiguous space. + */ + + if (av->sbrk_base != NONCONTIGUOUS_REGIONS) + size -= old_size; + + /* + Round to a multiple of page size. + If MORECORE is not contiguous, this ensures that we only call it + with whole-page arguments. And if MORECORE is contiguous and + this is not first time through, this preserves page-alignment of + previous calls. Otherwise, we re-correct anyway to page-align below. + */ + + size = (size + pagemask) & ~pagemask; + + /* + Don't try to call MORECORE if argument is so big as to appear + negative. Note that since mmap takes size_t arg, it may succeed + below even if we cannot call MORECORE. + */ + + if (size > 0) + brk = (char*)(MORECORE(size)); + + /* + If have mmap, try using it as a backup when MORECORE fails. This + is worth doing on systems that have "holes" in address space, so + sbrk cannot extend to give contiguous space, but space is available + elsewhere. Note that we ignore mmap max count and threshold limits, + since there is no reason to artificially limit use here. + */ + +#if HAVE_MMAP + if (brk == (char*)(MORECORE_FAILURE)) { + + /* Cannot merge with old top, so add its size back in */ + + if (av->sbrk_base != NONCONTIGUOUS_REGIONS) + size = (size + old_size + pagemask) & ~pagemask; + + /* If we are relying on mmap as backup, then use larger units */ + + if ((unsigned long)size < (unsigned long)MMAP_AS_MORECORE_SIZE) + size = MMAP_AS_MORECORE_SIZE; + + brk = (char*)(MMAP(0, size, PROT_READ|PROT_WRITE, MAP_PRIVATE)); + + if (brk != (char*)(MORECORE_FAILURE)) { + + /* We do not need, and cannot use, another sbrk call to find end */ + snd_brk = brk + size; + + /* + Record that we no longer have a contiguous sbrk region. + After the first time mmap is used as backup, we cannot + ever rely on contiguous space. + */ + av->sbrk_base = NONCONTIGUOUS_REGIONS; + } + } +#endif + + if (brk != (char*)(MORECORE_FAILURE)) { + + av->sbrked_mem += size; + + /* + If MORECORE extends previous space, we can likewise extend top size. + */ + + if (brk == old_end && snd_brk == (char*)(MORECORE_FAILURE)) { + set_head(old_top, (size + old_size) | PREV_INUSE); + } + + /* + Otherwise, make adjustments guided by the special values of + av->sbrk_base (MORECORE_FAILURE or NONCONTIGUOUS_REGIONS): + + * If the first time through or noncontiguous, we need to call sbrk + just to find out where the end of memory lies. + + * We need to ensure that all returned chunks from malloc will meet + MALLOC_ALIGNMENT + + * If there was an intervening foreign sbrk, we need to adjust sbrk + request size to account for fact that we will not be able to + combine new space with existing space in old_top. + + * Almost all systems internally allocate whole pages at a time, in + which case we might as well use the whole last page of request. + So we allocate enough more memory to hit a page boundary now, + which in turn causes future contiguous calls to page-align. + + */ + + else { + front_misalign = 0; + end_misalign = 0; + correction = 0; + aligned_brk = brk; + + /* handle contiguous cases */ + if (av->sbrk_base != NONCONTIGUOUS_REGIONS) { + + /* Guarantee alignment of first new chunk made from this space */ + + front_misalign = (INTERNAL_SIZE_T)chunk2mem(brk) & MALLOC_ALIGN_MASK; + if (front_misalign > 0) { + + /* + Skip over some bytes to arrive at an aligned position. + We don't need to specially mark these wasted front bytes. + They will never be accessed anyway because + prev_inuse of av->top (and any chunk created from its start) + is always true after initialization. + */ + + correction = MALLOC_ALIGNMENT - front_misalign; + aligned_brk += correction; + } + + /* + If this isn't adjacent to a previous sbrk, then we will not + be able to merge with old_top space, so must add to 2nd request. + */ + + correction += old_size; + + /* Pad out to hit a page boundary */ + + end_misalign = (INTERNAL_SIZE_T)(brk + size + correction); + correction += ((end_misalign + pagemask) & ~pagemask) - end_misalign; + + assert(correction >= 0); + + snd_brk = (char*)(MORECORE(correction)); + + /* + If can't allocate correction, try to at least find out current + brk. It might be enough to proceed without failing. + + Note that if second sbrk did NOT fail, we assume that space + is contiguous with first sbrk. This is a safe assumption unless + program is multithreaded but doesn't use locks and a foreign sbrk + occurred between our first and second calls. + */ + + if (snd_brk == (char*)(MORECORE_FAILURE)) { + correction = 0; + snd_brk = (char*)(MORECORE(0)); + } + } + + /* handle non-contiguous cases */ + else { + + /* MORECORE/mmap must correctly align etc */ + assert(((unsigned long)chunk2mem(brk) & MALLOC_ALIGN_MASK) == 0); + + /* Find out current end of memory */ + if (snd_brk == (char*)(MORECORE_FAILURE)) { + snd_brk = (char*)(MORECORE(0)); + } + + /* This must lie on a page boundary */ + if (snd_brk != (char*)(MORECORE_FAILURE)) { + assert(((INTERNAL_SIZE_T)(snd_brk) & pagemask) == 0); + } + } + + /* Adjust top based on results of second sbrk */ + if (snd_brk != (char*)(MORECORE_FAILURE)) { + + av->top = (mchunkptr)aligned_brk; + set_head(av->top, (snd_brk - aligned_brk + correction) | PREV_INUSE); + + av->sbrked_mem += correction; + + /* If first time through and contiguous, record base */ + if (old_top == initial_top(av)) { + if (av->sbrk_base == (char*)(MORECORE_FAILURE)) + av->sbrk_base = brk; + } + + /* + Otherwise, we either have a gap due to foreign sbrk or a + non-contiguous region. Insert a double fencepost at old_top + to prevent consolidation with space we don't own. These + fenceposts are artificial chunks that are marked as inuse + and are in any case too small to use. We need two to make + sizes and alignments work out. + */ + + else { + + /* + Shrink old_top to insert fenceposts, keeping size a + multiple of MALLOC_ALIGNMENT. + */ + old_size = (old_size - 3*SIZE_SZ) & ~MALLOC_ALIGN_MASK; + set_head(old_top, old_size | PREV_INUSE); + + /* + Note that the following assignments overwrite old_top when + old_size was previously MINSIZE. This is intentional. We + need the fencepost, even if old_top otherwise gets lost. + */ + chunk_at_offset(old_top, old_size )->size = + SIZE_SZ|PREV_INUSE; + + chunk_at_offset(old_top, old_size + SIZE_SZ)->size = + SIZE_SZ|PREV_INUSE; + + /* If possible, release the rest. */ + if (old_size >= MINSIZE) + fREe(chunk2mem(old_top)); + + } + } + } + + /* Update statistics */ + + sum = av->sbrked_mem; + if (sum > (unsigned long)(av->max_sbrked_mem)) + av->max_sbrked_mem = sum; + + sum += av->mmapped_mem; + if (sum > (unsigned long)(av->max_total_mem)) + av->max_total_mem = sum; + + check_malloc_state(); + + /* finally, do the allocation */ + + p = av->top; + size = chunksize(p); + remainder_size = (long)size - (long)nb; + + /* check that one of the above allocation paths succeeded */ + if (remainder_size >= (long)MINSIZE) { + remainder = chunk_at_offset(p, nb); + av->top = remainder; + set_head(p, nb | PREV_INUSE); + set_head(remainder, remainder_size | PREV_INUSE); + + check_malloced_chunk(p, nb); + return chunk2mem(p); + } + } + + /* catch all failure paths */ + MALLOC_FAILURE_ACTION; + return 0; +} + + +/* + sYSTRIm is an inverse of sorts to sYSMALLOc. + It gives memory back to the system (via negative + arguments to sbrk) if there is unused memory at the `high' end of + the malloc pool. It is called automatically by free() + when top space exceeds the trim threshold. + returns 1 if it actually released any memory, else 0. +*/ + +#if __STD_C +static int sYSTRIm(size_t pad, mstate av) +#else +static int sYSTRIm(pad, av) size_t pad; mstate av; +#endif +{ + long top_size; /* Amount of top-most memory */ + long extra; /* Amount to release */ + long released; /* Amount actually released */ + char* current_brk; /* address returned by pre-check sbrk call */ + char* new_brk; /* address returned by post-check sbrk call */ + size_t pagesz; + + /* Don't bother trying if sbrk doesn't provide contiguous regions */ + if (av->sbrk_base != NONCONTIGUOUS_REGIONS) { + + pagesz = av->pagesize; + top_size = chunksize(av->top); + + /* Release in pagesize units, keeping at least one page */ + extra = ((top_size - pad - MINSIZE + (pagesz-1)) / pagesz - 1) * pagesz; + + if (extra > 0) { + + /* + Only proceed if end of memory is where we last set it. + This avoids problems if there were foreign sbrk calls. + */ + current_brk = (char*)(MORECORE(0)); + if (current_brk == (char*)(av->top) + top_size) { + + /* + Attempt to release memory. We ignore return value, + and instead call again to find out where new end of memory is. + This avoids problems if first call releases less than we asked, + of if failure somehow altered brk value. (We could still + encounter problems if it altered brk in some very bad way, + but the only thing we can do is adjust anyway, which will cause + some downstream failure.) + */ + + MORECORE(-extra); + new_brk = (char*)(MORECORE(0)); + + if (new_brk != (char*)MORECORE_FAILURE) { + released = (long)(current_brk - new_brk); + + if (released != 0) { + /* Success. Adjust top. */ + av->sbrked_mem -= released; + set_head(av->top, (top_size - released) | PREV_INUSE); + check_malloc_state(); + return 1; + } + } + } + } + } + + return 0; +} + +/* ----------------------- Main public routines ----------------------- */ + + +/* + Malloc routine. See running comments for algorithm description. +*/ + +#if __STD_C +Void_t* mALLOc(size_t bytes) +#else + Void_t* mALLOc(bytes) size_t bytes; +#endif +{ + mstate av = get_malloc_state(); + + INTERNAL_SIZE_T nb; /* normalized request size */ + unsigned int idx; /* associated bin index */ + mbinptr bin; /* associated bin */ + mfastbinptr* fb; /* associated fastbin */ + + mchunkptr victim; /* inspected/selected chunk */ + INTERNAL_SIZE_T size; /* its size */ + int victim_index; /* its bin index */ + + mchunkptr remainder; /* remainder from a split */ + long remainder_size; /* its size */ + + unsigned int block; /* bit map traverser */ + unsigned int bit; /* bit map traverser */ + unsigned int map; /* current word of binmap */ + + mchunkptr fwd; /* misc temp for linking */ + mchunkptr bck; /* misc temp for linking */ + + + /* + Check request for legality and convert to internal form, nb. + This rejects negative arguments when size_t is treated as + signed. It also rejects arguments that are so large that the size + appears negative when aligned and padded. The converted form + adds SIZE_T bytes overhead plus possibly more to obtain necessary + alignment and/or to obtain a size of at least MINSIZE, the + smallest allocatable size. + */ + + checked_request2size(bytes, nb); + + /* + If the size qualifies as a fastbin, first check corresponding bin. + This code is safe to execute even if av not yet initialized, so we + can try it first, which saves some time on this fast path. + */ + + if (nb <= av->max_fast) { + fb = &(av->fastbins[(fastbin_index(nb))]); + if ( (victim = *fb) != 0) { + *fb = victim->fd; + check_remalloced_chunk(victim, nb); + return chunk2mem(victim); + } + } + + /* + If a small request, check regular bin. Since these "smallbins" + hold one size each, no searching within bins is necessary. + + (If a large request, we need to wait until unsorted chunks are + processed to find best fit. But for small ones, fits are exact + anyway, so we can check now, which is faster.) + */ + + if (in_smallbin_range(nb)) { + idx = smallbin_index(nb); + bin = bin_at(av,idx); + + if ( (victim = last(bin)) != bin) { + if (victim == 0) /* initialization check */ + malloc_consolidate(av); + else { + bck = victim->bk; + set_inuse_bit_at_offset(victim, nb); + bin->bk = bck; + bck->fd = bin; + + check_malloced_chunk(victim, nb); + return chunk2mem(victim); + } + } + } + + /* + If a large request, consolidate fastbins before continuing. + While it might look excessive to kill all fastbins before + even seeing if there is space available, this avoids + fragmentation problems normally associated with fastbins. + Also, in practice, programs tend to have runs of either small or + large requests, but less often mixtures, so consolidation is not + usually invoked all that often. + */ + + else { + idx = largebin_index(nb); + if (have_fastchunks(av)) /* consolidation/initialization check */ + malloc_consolidate(av); + } + + + /* + Process recently freed or remaindered chunks, taking one only if + it is exact fit, or, if a small request, it is the remainder from + the most recent non-exact fit. Place other traversed chunks in + bins. Note that this step is the only place in any routine where + chunks are placed in bins. + + The outer loop here is needed because we might not realize until + near the end of malloc that we should have consolidated, so must + do so and retry. This happens at most once, and only when we would + otherwise need to expand memory to service a "small" request. + */ + + + for(;;) { + + while ( (victim = unsorted_chunks(av)->bk) != unsorted_chunks(av)) { + bck = victim->bk; + size = chunksize(victim); + + /* + If a small request, try to use last remainder if it is the + only chunk in unsorted bin. This helps promote locality for + runs of consecutive small requests. This is the only + exception to best-fit. + */ + + if (in_smallbin_range(nb) && + victim == av->last_remainder && + bck == unsorted_chunks(av) && + (remainder_size = (long)size - (long)nb) >= (long)MINSIZE) { + + /* split and reattach remainder */ + remainder = chunk_at_offset(victim, nb); + unsorted_chunks(av)->bk = unsorted_chunks(av)->fd = remainder; + av->last_remainder = remainder; + remainder->bk = remainder->fd = unsorted_chunks(av); + + set_head(victim, nb | PREV_INUSE); + set_head(remainder, remainder_size | PREV_INUSE); + set_foot(remainder, remainder_size); + + check_malloced_chunk(victim, nb); + return chunk2mem(victim); + } + + /* remove from unsorted list */ + unsorted_chunks(av)->bk = bck; + bck->fd = unsorted_chunks(av); + + /* Take now instead of binning if exact fit */ + + if (size == nb) { + set_inuse_bit_at_offset(victim, size); + check_malloced_chunk(victim, nb); + return chunk2mem(victim); + } + + /* place chunk in bin */ + + if (in_smallbin_range(size)) { + victim_index = smallbin_index(size); + bck = bin_at(av, victim_index); + fwd = bck->fd; + } + else { + victim_index = largebin_index(size); + bck = bin_at(av, victim_index); + fwd = bck->fd; + + /* maintain large bins in sorted order */ + if (fwd != bck) { + /* if smaller than smallest, bypass loop below */ + if ((unsigned long)size <= + (unsigned long)(chunksize(bck->bk))) { + fwd = bck; + bck = bck->bk; + } + else { + while (fwd != bck && + (unsigned long)size < (unsigned long)(chunksize(fwd))) { + fwd = fwd->fd; + } + bck = fwd->bk; + } + } + } + + mark_bin(av, victim_index); + victim->bk = bck; + victim->fd = fwd; + fwd->bk = victim; + bck->fd = victim; + } + + /* + If a large request, scan through the chunks of current bin in + sorted order to find smallest that fits. This is the only step + where an unbounded number of chunks might be scanned without doing + anything useful with them. However the lists tend to be very + short. + */ + + if (!in_smallbin_range(nb)) { + bin = bin_at(av, idx); + + /* skip scan if largest chunk is too small */ + if ((victim = last(bin)) != bin && + (long)(chunksize(first(bin))) - (long)(nb) >= 0) { + do { + size = chunksize(victim); + remainder_size = (long)size - (long)nb; + + if (remainder_size >= 0) { + unlink(victim, bck, fwd); + + /* Exhaust */ + if (remainder_size < (long)MINSIZE) { + set_inuse_bit_at_offset(victim, size); + check_malloced_chunk(victim, nb); + return chunk2mem(victim); + } + /* Split */ + else { + remainder = chunk_at_offset(victim, nb); + unsorted_chunks(av)->bk = unsorted_chunks(av)->fd = remainder; + remainder->bk = remainder->fd = unsorted_chunks(av); + set_head(victim, nb | PREV_INUSE); + set_head(remainder, remainder_size | PREV_INUSE); + set_foot(remainder, remainder_size); + check_malloced_chunk(victim, nb); + return chunk2mem(victim); + } + } + } while ( (victim = victim->bk) != bin); + } + } + + /* + Search for a chunk by scanning bins, starting with next largest + bin. 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. + + The bitmap avoids needing to check that most blocks are nonempty. + The particular case of skipping all bins during warm-up phases + when no chunks have been returned yet is faster than it might look. + */ + + ++idx; + bin = bin_at(av,idx); + block = idx2block(idx); + map = av->binmap[block]; + bit = idx2bit(idx); + + for (;;) { + /* + Skip rest of block if there are no more set bits in this block. + */ + + if (bit > map || bit == 0) { + for (;;) { + if (++block >= BINMAPSIZE) /* out of bins */ + break; + + else if ( (map = av->binmap[block]) != 0) { + bin = bin_at(av, (block << BINMAPSHIFT)); + bit = 1; + break; + } + } + /* Optimizers seem to like this double-break better than goto */ + if (block >= BINMAPSIZE) + break; + } + + /* Advance to bin with set bit. There must be one. */ + while ((bit & map) == 0) { + bin = next_bin(bin); + bit <<= 1; + } + + victim = last(bin); + + /* False alarm -- the bin is empty. Clear the bit. */ + if (victim == bin) { + av->binmap[block] = map &= ~bit; /* Write through */ + bin = next_bin(bin); + bit <<= 1; + } + + /* We know the first chunk in this bin is big enough to use. */ + else { + size = chunksize(victim); + remainder_size = (long)size - (long)nb; + + assert(remainder_size >= 0); + + /* unlink */ + bck = victim->bk; + bin->bk = bck; + bck->fd = bin; + + + /* Exhaust */ + if (remainder_size < (long)MINSIZE) { + set_inuse_bit_at_offset(victim, size); + check_malloced_chunk(victim, nb); + return chunk2mem(victim); + } + + /* Split */ + else { + remainder = chunk_at_offset(victim, nb); + + unsorted_chunks(av)->bk = unsorted_chunks(av)->fd = remainder; + remainder->bk = remainder->fd = unsorted_chunks(av); + /* advertise as last remainder */ + if (in_smallbin_range(nb)) + av->last_remainder = remainder; + + set_head(victim, nb | PREV_INUSE); + set_head(remainder, remainder_size | PREV_INUSE); + set_foot(remainder, remainder_size); + check_malloced_chunk(victim, nb); + return chunk2mem(victim); + } + } + } + + /* + If large enough, split off the chunk bordering the end of memory + ("top"). Note that 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). + + We require that "top" always exists (i.e., has size >= MINSIZE) + after initialization, so if it would otherwise be exhuasted by + current request, it is replenished. (Among the reasons for + ensuring it exists is that we may need MINSIZE space to put in + fenceposts in sysmalloc.) + */ + + victim = av->top; + size = chunksize(victim); + remainder_size = (long)size - (long)nb; + + if (remainder_size >= (long)MINSIZE) { + remainder = chunk_at_offset(victim, nb); + av->top = remainder; + set_head(victim, nb | PREV_INUSE); + set_head(remainder, remainder_size | PREV_INUSE); + + check_malloced_chunk(victim, nb); + return chunk2mem(victim); + } + + /* + If there is space available in fastbins, consolidate and retry, + to possibly avoid expanding memory. This can occur only if nb is + in smallbin range so we didn't consolidate upon entry. + */ + + else if (have_fastchunks(av)) { + assert(in_smallbin_range(nb)); + idx = smallbin_index(nb); /* restore original bin index */ + malloc_consolidate(av); + } + + /* + Otherwise, relay to handle system-dependent cases + */ + else + return sYSMALLOc(nb, av); + } +} + + + +/* + Free routine. See running comments for algorithm description. +*/ + +#if __STD_C +void fREe(Void_t* mem) +#else +void fREe(mem) Void_t* mem; +#endif +{ + mstate av = get_malloc_state(); + + mchunkptr p; /* chunk corresponding to mem */ + INTERNAL_SIZE_T size; /* its size */ + mfastbinptr* fb; /* associated fastbin */ + mchunkptr nextchunk; /* next contiguous chunk */ + INTERNAL_SIZE_T nextsize; /* its size */ + int nextinuse; /* true if nextchunk is used */ + INTERNAL_SIZE_T prevsize; /* size of previous contiguous chunk */ + mchunkptr bck; /* misc temp for linking */ + mchunkptr fwd; /* misc temp for linking */ + + + /* free(0) has no effect */ + if (mem != 0) { + + p = mem2chunk(mem); + check_inuse_chunk(p); + + size = chunksize(p); + + /* + If eligible, place chunk on a fastbin so it can be found + and used quickly in malloc. + */ + + if ((unsigned long)size <= (unsigned long)av->max_fast + +#if TRIM_FASTBINS + /* + If TRIM_FASTBINS set, don't place chunks + bordering top into fastbins + */ + && (chunk_at_offset(p, size) != av->top) +#endif + ) { + + set_fastchunks(av); + fb = &(av->fastbins[fastbin_index(size)]); + p->fd = *fb; + *fb = p; + } + + /* + Consolidate non-mmapped chunks as they arrive. + */ + + else if (!chunk_is_mmapped(p)) { + + nextchunk = chunk_at_offset(p, size); + + /* consolidate backward */ + if (!prev_inuse(p)) { + prevsize = p->prev_size; + size += prevsize; + p = chunk_at_offset(p, -((long) prevsize)); + unlink(p, bck, fwd); + } + + nextsize = chunksize(nextchunk); + + if (nextchunk != av->top) { + + /* get and clear inuse bit */ + nextinuse = inuse_bit_at_offset(nextchunk, nextsize); + set_head(nextchunk, nextsize); + + /* consolidate forward */ + if (!nextinuse) { + unlink(nextchunk, bck, fwd); + size += nextsize; + } + + /* + Place chunk in unsorted chunk list. Chunks are + not placed into regular bins until after they have + been given one chance to be used in malloc. + */ + + bck = unsorted_chunks(av); + fwd = bck->fd; + p->bk = bck; + p->fd = fwd; + bck->fd = p; + fwd->bk = p; + + set_head(p, size | PREV_INUSE); + set_foot(p, size); + } + + /* + If the chunk borders the current high end of memory, + consolidate into top + */ + + else { + size += nextsize; + set_head(p, size | PREV_INUSE); + av->top = p; + + /* + If the total unused topmost memory exceeds trim + threshold, ask malloc_trim to reduce top. + + Unless max_fast is 0, we don't know if there are fastbins + bordering top, so we cannot tell for sure whether threshold has + been reached unless fastbins are consolidated. But we don't + want to consolidate on each free. As a compromise, + consolidation is performed if half the threshold is + reached. + + */ + + if ((unsigned long)(size) > (unsigned long)(av->trim_threshold / 2)) { + if (have_fastchunks(av)) { + malloc_consolidate(av); + size = chunksize(av->top); + } + + if ((unsigned long)(size) > (unsigned long)(av->trim_threshold)) + sYSTRIm(av->top_pad, av); + } + } + } + + /* + If the chunk was allocated via mmap, release via munmap() + Note that if HAVE_MMAP is false but chunk_is_mmapped is + true, then user must have overwritten memory. There's nothing + we can do to catch this error unless DEBUG is set, in which case + check_inuse_chunk (above) will have triggered error. + */ + + else { +#if HAVE_MMAP + int ret; + INTERNAL_SIZE_T offset = p->prev_size; + av->n_mmaps--; + av->mmapped_mem -= (size + offset); + ret = munmap((char*)p - offset, size + offset); + /* munmap returns non-zero on failure */ + assert(ret == 0); +#endif + } + } +} + + + +/* + malloc_consolidate is a specialized version of free() that tears + down chunks held in fastbins. Free itself cannot be used for this + purpose since, among other things, it might place chunks back onto + fastbins. So, instead, we need to use a minor variant of the same + code. + + Also, because this routine needs to be called the first time through + malloc anyway, it turns out to be the perfect place to bury + initialization code. +*/ + +#if __STD_C +static void malloc_consolidate(mstate av) +#else +static void malloc_consolidate(av) mstate av; +#endif +{ + mfastbinptr* fb; + mfastbinptr* maxfb; + mchunkptr p; + mchunkptr nextp; + mchunkptr unsorted_bin; + mchunkptr first_unsorted; + + /* These have same use as in free() */ + mchunkptr nextchunk; + INTERNAL_SIZE_T size; + INTERNAL_SIZE_T nextsize; + INTERNAL_SIZE_T prevsize; + int nextinuse; + mchunkptr bck; + mchunkptr fwd; + + /* + If max_fast is 0, we know that malloc hasn't + yet been initialized, in which case do so. + */ + + if (av->max_fast == 0) { + malloc_init_state(av); + check_malloc_state(); + } + else if (have_fastchunks(av)) { + clear_fastchunks(av); + + unsorted_bin = unsorted_chunks(av); + + /* + Remove each chunk from fast bin and consolidate it, placing it + then in unsorted bin. Among other reasons for doing this, + placing in unsorted bin avoids needing to calculate actual bins + until malloc is sure that chunks aren't immediately going to be + reused anyway. + */ + + maxfb = &(av->fastbins[fastbin_index(av->max_fast)]); + fb = &(av->fastbins[0]); + do { + if ( (p = *fb) != 0) { + *fb = 0; + + do { + check_inuse_chunk(p); + nextp = p->fd; + + /* Slightly streamlined version of consolidation code in free() */ + size = p->size & ~PREV_INUSE; + nextchunk = chunk_at_offset(p, size); + + if (!prev_inuse(p)) { + prevsize = p->prev_size; + size += prevsize; + p = chunk_at_offset(p, -((long) prevsize)); + unlink(p, bck, fwd); + } + + nextsize = chunksize(nextchunk); + + if (nextchunk != av->top) { + + nextinuse = inuse_bit_at_offset(nextchunk, nextsize); + set_head(nextchunk, nextsize); + + if (!nextinuse) { + size += nextsize; + unlink(nextchunk, bck, fwd); + } + + first_unsorted = unsorted_bin->fd; + unsorted_bin->fd = p; + first_unsorted->bk = p; + + set_head(p, size | PREV_INUSE); + p->bk = unsorted_bin; + p->fd = first_unsorted; + set_foot(p, size); + } + + else { + size += nextsize; + set_head(p, size | PREV_INUSE); + av->top = p; + } + + } while ( (p = nextp) != 0); + + } + } while (fb++ != maxfb); + } +} + + + + +/* + Realloc algorithm cases: + + * Chunks that were obtained via mmap cannot be extended or shrunk + unless HAVE_MREMAP is defined, in which case mremap is used. + Otherwise, if the 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 + + * If there is not enough memory available to realloc, realloc + returns null, but does NOT free the existing space. + + * If the reallocation is for less space, the newly unused space is + lopped off and freed. Unless the #define REALLOC_ZERO_BYTES_FREES + is set, realloc with a size argument of zero (re)allocates a + minimum-sized chunk. + + + 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 +{ + mstate av = get_malloc_state(); + + 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 */ + mchunkptr prev; /* previous contiguous chunk before oldp */ + + mchunkptr remainder; /* extra space at end of newp */ + long remainder_size; /* its size */ + + mchunkptr bck; /* misc temp for linking */ + mchunkptr fwd; /* misc temp for linking */ + + INTERNAL_SIZE_T copysize; /* bytes to copy */ + int ncopies; /* INTERNAL_SIZE_T words to copy */ + INTERNAL_SIZE_T* s; /* copy source */ + INTERNAL_SIZE_T* d; /* copy destination */ + + +#ifdef REALLOC_ZERO_BYTES_FREES + if (bytes == 0) { + fREe(oldmem); + return 0; + } +#endif + + /* realloc of null is supposed to be same as malloc */ + if (oldmem == 0) return mALLOc(bytes); + + checked_request2size(bytes, nb); + + oldp = mem2chunk(oldmem); + oldsize = chunksize(oldp); + + check_inuse_chunk(oldp); + + if (!chunk_is_mmapped(oldp)) { + + if ((unsigned long)(oldsize) >= (unsigned long)(nb)) { + /* already big enough; split below */ + newp = oldp; + newsize = oldsize; + } + + else { + newp = 0; + newsize = 0; + + next = chunk_at_offset(oldp, oldsize); + + if (next == av->top) { /* Expand forward into top */ + newsize = oldsize + chunksize(next); + + if ((unsigned long)(newsize) >= (unsigned long)(nb + MINSIZE)) { + set_head_size(oldp, nb); + av->top = chunk_at_offset(oldp, nb); + set_head(av->top, (newsize - nb) | PREV_INUSE); + return chunk2mem(oldp); + } + + else if (!prev_inuse(oldp)) { /* Shift backwards + top */ + prev = prev_chunk(oldp); + newsize += chunksize(prev); + + if ((unsigned long)(newsize) >= (unsigned long)(nb + MINSIZE)) { + newp = prev; + unlink(prev, bck, fwd); + av->top = chunk_at_offset(newp, nb); + set_head(av->top, (newsize - nb) | PREV_INUSE); + newsize = nb; + } + } + } + + else if (!inuse(next)) { /* Forward into next chunk */ + newsize = oldsize + chunksize(next); + + if (((unsigned long)(newsize) >= (unsigned long)(nb))) { + newp = oldp; + unlink(next, bck, fwd); + } + + else if (!prev_inuse(oldp)) { /* Forward + backward */ + prev = prev_chunk(oldp); + newsize += chunksize(prev); + + if (((unsigned long)(newsize) >= (unsigned long)(nb))) { + newp = prev; + unlink(prev, bck, fwd); + unlink(next, bck, fwd); + } + } + } + + else if (!prev_inuse(oldp)) { /* Backward only */ + prev = prev_chunk(oldp); + newsize = oldsize + chunksize(prev); + + if ((unsigned long)(newsize) >= (unsigned long)(nb)) { + newp = prev; + unlink(prev, bck, fwd); + } + } + + if (newp != 0) { + if (newp != oldp) { + /* Backward copies are not worth unrolling */ + MALLOC_COPY(chunk2mem(newp), oldmem, oldsize - SIZE_SZ, 1); + } + } + + /* Must allocate */ + else { + newmem = mALLOc(nb - MALLOC_ALIGN_MASK); + if (newmem == 0) + return 0; /* propagate failure */ + + newp = mem2chunk(newmem); + newsize = chunksize(newp); + + /* + Avoid copy if newp is next chunk after oldp. + */ + if (newp == next) { + newsize += oldsize; + newp = oldp; + } + else { + + /* + Unroll copy of <= 36 bytes (72 if 8byte sizes) + We know that contents have an odd number of + INTERNAL_SIZE_T-sized words; minimally 3. + */ + + copysize = oldsize - SIZE_SZ; + s = (INTERNAL_SIZE_T*)oldmem; + d = (INTERNAL_SIZE_T*)(chunk2mem(newp)); + ncopies = copysize / sizeof(INTERNAL_SIZE_T); + assert(ncopies >= 3); + + if (ncopies > 9) + MALLOC_COPY(d, s, copysize, 0); + + else { + *(d+0) = *(s+0); + *(d+1) = *(s+1); + *(d+2) = *(s+2); + if (ncopies > 4) { + *(d+3) = *(s+3); + *(d+4) = *(s+4); + if (ncopies > 6) { + *(d+5) = *(s+5); + *(d+6) = *(s+6); + if (ncopies > 8) { + *(d+7) = *(s+7); + *(d+8) = *(s+8); + } + } + } + } + + fREe(oldmem); + check_inuse_chunk(newp); + return chunk2mem(newp); + } + } + } + + + /* If possible, free extra space in old or extended chunk */ + + remainder_size = (long)newsize - (long)nb; + assert(remainder_size >= 0); + + if (remainder_size >= (long)MINSIZE) { /* split remainder */ + remainder = chunk_at_offset(newp, nb); + set_head_size(newp, nb); + set_head(remainder, remainder_size | PREV_INUSE); + /* Mark remainder as inuse so free() won't complain */ + set_inuse_bit_at_offset(remainder, remainder_size); + fREe(chunk2mem(remainder)); + } + + else { /* not enough extra to split off */ + set_head_size(newp, newsize); + set_inuse_bit_at_offset(newp, newsize); + } + + check_inuse_chunk(newp); + return chunk2mem(newp); + } + + /* + Handle mmap cases + */ + + else { +#if HAVE_MMAP + +#if HAVE_MREMAP + INTERNAL_SIZE_T offset = oldp->prev_size; + size_t pagemask = av->pagesize - 1; + char *cp; + unsigned long sum; + + /* Note the extra SIZE_SZ overhead */ + newsize = (nb + offset + SIZE_SZ + pagemask) & ~pagemask; + + /* don't need to remap if still within same page */ + if (oldsize == newsize - offset) + return oldmem; + + cp = (char*)mremap((char*)oldp - offset, oldsize + offset, newsize, 1); + + if (cp != (char*)MORECORE_FAILURE) { + + newp = (mchunkptr)(cp + offset); + set_head(newp, (newsize - offset)|IS_MMAPPED); + + assert(aligned_OK(chunk2mem(newp))); + assert((newp->prev_size == offset)); + + /* update statistics */ + sum = av->mmapped_mem += newsize - oldsize; + if (sum > (unsigned long)(av->max_mmapped_mem)) + av->max_mmapped_mem = sum; + sum += av->sbrked_mem; + if (sum > (unsigned long)(av->max_total_mem)) + av->max_total_mem = sum; + + return chunk2mem(newp); + } + +#endif + + /* Note the extra SIZE_SZ overhead. */ + if ((long)oldsize - (long)SIZE_SZ >= (long)nb) + newmem = oldmem; /* do nothing */ + else { + /* Must alloc, copy, free. */ + newmem = mALLOc(nb - MALLOC_ALIGN_MASK); + if (newmem != 0) { + MALLOC_COPY(newmem, oldmem, oldsize - 2*SIZE_SZ, 0); + fREe(oldmem); + } + } + return newmem; + +#else + /* If !HAVE_MMAP, but chunk_is_mmapped, user must have overwritten mem */ + check_malloc_state(); + MALLOC_FAILURE_ACTION; + return 0; +#endif + } + +} + + + +/* + 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. + + Alignments must be powers of two. If the argument is not a + power of two, the nearest greater power is used. + + 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 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; + + /* Make sure alignment is power of 2 (in case MINSIZE is not). */ + if ((alignment & (alignment - 1)) != 0) { + size_t a = MALLOC_ALIGNMENT * 2; + while ((unsigned long)a < (unsigned long)alignment) a <<= 1; + alignment = a; + } + + checked_request2size(bytes, nb); + + /* Call malloc with worst case padding to hit alignment. */ + + m = (char*)(mALLOc(nb + alignment + MINSIZE)); + + if (m == 0) return 0; /* propagate failure */ + + p = mem2chunk(m); + + if ((((unsigned long)(m)) % alignment) != 0) { /* 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 long) alignment)); + if ((long)(brk - (char*)(p)) < (long)MINSIZE) + brk = brk + alignment; + + newp = (mchunkptr)brk; + leadsize = brk - (char*)(p); + newsize = chunksize(p) - leadsize; + + /* For mmapped chunks, just adjust offset */ + if (chunk_is_mmapped(p)) { + newp->prev_size = p->prev_size + leadsize; + set_head(newp, newsize|IS_MMAPPED); + return chunk2mem(newp); + } + + /* Otherwise, 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 */ + if (!chunk_is_mmapped(p)) { + + remainder_size = (long)(chunksize(p)) - (long)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); + +} + + + + +/* + calloc calls malloc, then zeroes out the allocated chunk. +*/ + +#if __STD_C +Void_t* cALLOc(size_t n_elements, size_t elem_size) +#else +Void_t* cALLOc(n_elements, elem_size) size_t n_elements; size_t elem_size; +#endif +{ + mchunkptr p; + INTERNAL_SIZE_T clearsize; + int nclears; + INTERNAL_SIZE_T* d; + + Void_t* mem = mALLOc(n_elements * elem_size); + + if (mem != 0) { + p = mem2chunk(mem); + if (!chunk_is_mmapped(p)) { /* don't need to clear mmapped space */ + + /* + Unroll clear of <= 36 bytes (72 if 8byte sizes) + We know that contents have an odd number of + INTERNAL_SIZE_T-sized words; minimally 3. + */ + + d = (INTERNAL_SIZE_T*)mem; + clearsize = chunksize(p) - SIZE_SZ; + nclears = clearsize / sizeof(INTERNAL_SIZE_T); + assert(nclears >= 3); + + if (nclears > 9) + MALLOC_ZERO(d, clearsize); + + else { + *(d+0) = 0; + *(d+1) = 0; + *(d+2) = 0; + if (nclears > 4) { + *(d+3) = 0; + *(d+4) = 0; + if (nclears > 6) { + *(d+5) = 0; + *(d+6) = 0; + if (nclears > 8) { + *(d+7) = 0; + *(d+8) = 0; + } + } + } + } + } + } + return mem; +} + + +/* + cfree just calls free. It is needed/defined on some systems + that pair it with calloc, presumably for odd historical reasons + (such as: cfree is used in example code in first edition of K&R). +*/ + +#if __STD_C +void cFREe(Void_t *mem) +#else +void cFREe(mem) Void_t *mem; +#endif +{ + fREe(mem); +} + + + + + +/* + 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 +{ + /* Ensure initialization/consolidation */ + mstate av = get_malloc_state(); + malloc_consolidate(av); + return mEMALIGn(av->pagesize, 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 +{ + mstate av = get_malloc_state(); + size_t pagesz; + + /* Ensure initialization/consolidation */ + malloc_consolidate(av); + + pagesz = av->pagesize; + return mEMALIGn(pagesz, (bytes + pagesz - 1) & ~(pagesz - 1)); +} + + +/* + 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 mTRIm(size_t pad) +#else +int mTRIm(pad) size_t pad; +#endif +{ + mstate av = get_malloc_state(); + /* Ensure initialization/consolidation */ + malloc_consolidate(av); + + return sYSTRIm(pad, av); +} + +/* + malloc_usable_size 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 mUSABLe(Void_t* mem) +#else +size_t mUSABLe(mem) Void_t* mem; +#endif +{ + mchunkptr p; + if (mem != 0) { + p = mem2chunk(mem); + if (chunk_is_mmapped(p)) + return chunksize(p) - 2*SIZE_SZ; + else if (inuse(p)) + return chunksize(p) - SIZE_SZ; + } + return 0; +} + + + + +/* + mallinfo returns a copy of updated current mallinfo. +*/ + +struct mallinfo mALLINFo() +{ + mstate av = get_malloc_state(); + struct mallinfo mi; + int i; + mbinptr b; + mchunkptr p; + INTERNAL_SIZE_T avail; + int navail; + int nfastblocks; + int fastbytes; + + /* Ensure initialization */ + if (av->top == 0) malloc_consolidate(av); + + check_malloc_state(); + + /* Account for top */ + avail = chunksize(av->top); + navail = 1; /* top always exists */ + + /* traverse fastbins */ + nfastblocks = 0; + fastbytes = 0; + + for (i = 0; i < NFASTBINS; ++i) { + for (p = av->fastbins[i]; p != 0; p = p->fd) { + ++nfastblocks; + fastbytes += chunksize(p); + } + } + + avail += fastbytes; + + /* traverse regular bins */ + for (i = 1; i < NBINS; ++i) { + b = bin_at(av, i); + for (p = last(b); p != b; p = p->bk) { + avail += chunksize(p); + navail++; + } + } + + mi.smblks = nfastblocks; + mi.ordblks = navail; + mi.fordblks = avail; + mi.uordblks = av->sbrked_mem - avail; + mi.arena = av->sbrked_mem; + mi.hblks = av->n_mmaps; + mi.hblkhd = av->mmapped_mem; + mi.fsmblks = fastbytes; + mi.keepcost = chunksize(av->top); + mi.usmblks = av->max_total_mem; + return mi; +} + + + +/* + malloc_stats prints on stderr the amount of space obtained 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), 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. Because it includes + alignment wastage as being in use, this figure may be greater than zero + even when no user-level chunks are allocated. + + The reported current and maximum system memory can be inaccurate if + a program makes other calls to system memory allocation functions + (normally sbrk) outside of malloc. + + malloc_stats prints only the most commonly interesting statistics. + More information can be obtained by calling mallinfo. +*/ + +void mSTATs() +{ + struct mallinfo mi = mALLINFo(); + +#ifdef WIN32 + { + unsigned long free, reserved, committed; + vminfo (&free, &reserved, &committed); + fprintf(stderr, "free bytes = %10lu\n", + free); + fprintf(stderr, "reserved bytes = %10lu\n", + reserved); + fprintf(stderr, "committed bytes = %10lu\n", + committed); + } +#endif + + + fprintf(stderr, "max system bytes = %10lu\n", + (unsigned long)(mi.usmblks)); + fprintf(stderr, "system bytes = %10lu\n", + (unsigned long)(mi.arena + mi.hblkhd)); + fprintf(stderr, "in use bytes = %10lu\n", + (unsigned long)(mi.uordblks + mi.hblkhd)); + +#ifdef WIN32 + { + unsigned long kernel, user; + if (cpuinfo (TRUE, &kernel, &user)) { + fprintf(stderr, "kernel ms = %10lu\n", + kernel); + fprintf(stderr, "user ms = %10lu\n", + user); + } + } +#endif +} + + + +/* + 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 for meanings. +*/ + +#if __STD_C +int mALLOPt(int param_number, int value) +#else +int mALLOPt(param_number, value) int param_number; int value; +#endif +{ + mstate av = get_malloc_state(); + /* Ensure initialization/consolidation */ + malloc_consolidate(av); + + switch(param_number) { + case M_MXFAST: + if (value >= 0 && value <= MAX_FAST_SIZE) { + av->max_fast = req2max_fast(value); + return 1; + } + else + return 0; + + case M_TRIM_THRESHOLD: + av->trim_threshold = value; + return 1; + + case M_TOP_PAD: + av->top_pad = value; + return 1; + + case M_MMAP_THRESHOLD: + av->mmap_threshold = value; + return 1; + + case M_MMAP_MAX: +#if HAVE_MMAP + av->n_mmaps_max = value; + return 1; +#else + if (value != 0) + return 0; + else { + av->n_mmaps_max = value; + return 1; + } +#endif + + default: + return 0; + } +} + + +/* -------------------------------------------------------------- */ + +/* + Emulation of sbrk for win32. + Donated by J. Walter <Walter@GeNeSys-e.de>. + For additional information about this code, and malloc on Win32, see + http://www.genesys-e.de/jwalter/ + +*/ + + +#ifdef WIN32 + +#ifdef _DEBUG +/* #define TRACE */ +#endif + +/* Support for USE_MALLOC_LOCK */ +#ifdef USE_MALLOC_LOCK + +/* Wait for spin lock */ +static int slwait (int *sl) { + while (InterlockedCompareExchange ((void **) sl, (void *) 1, (void *) 0) != 0) + Sleep (0); + return 0; +} + +/* Release spin lock */ +static int slrelease (int *sl) { + InterlockedExchange (sl, 0); + return 0; +} + +#ifdef NEEDED +/* Spin lock for emulation code */ +static int g_sl; +#endif + +#endif /* USE_MALLOC_LOCK */ + +/* getpagesize for windows */ +static long getpagesize (void) { + static long g_pagesize = 0; + if (! g_pagesize) { + SYSTEM_INFO system_info; + GetSystemInfo (&system_info); + g_pagesize = system_info.dwPageSize; + } + return g_pagesize; +} +static long getregionsize (void) { + static long g_regionsize = 0; + if (! g_regionsize) { + SYSTEM_INFO system_info; + GetSystemInfo (&system_info); + g_regionsize = system_info.dwAllocationGranularity; + } + return g_regionsize; +} + +/* A region list entry */ +typedef struct _region_list_entry { + void *top_allocated; + void *top_committed; + void *top_reserved; + long reserve_size; + struct _region_list_entry *previous; +} region_list_entry; + +/* Allocate and link a region entry in the region list */ +static int region_list_append (region_list_entry **last, void *base_reserved, long reserve_size) { + region_list_entry *next = HeapAlloc (GetProcessHeap (), 0, sizeof (region_list_entry)); + if (! next) + return FALSE; + next->top_allocated = (char *) base_reserved; + next->top_committed = (char *) base_reserved; + next->top_reserved = (char *) base_reserved + reserve_size; + next->reserve_size = reserve_size; + next->previous = *last; + *last = next; + return TRUE; +} +/* Free and unlink the last region entry from the region list */ +static int region_list_remove (region_list_entry **last) { + region_list_entry *previous = (*last)->previous; + if (! HeapFree (GetProcessHeap (), sizeof (region_list_entry), *last)) + return FALSE; + *last = previous; + return TRUE; +} + +#define CEIL(size,to) (((size)+(to)-1)&~((to)-1)) +#define FLOOR(size,to) ((size)&~((to)-1)) + +#define SBRK_SCALE 0 +/* #define SBRK_SCALE 1 */ +/* #define SBRK_SCALE 2 */ +/* #define SBRK_SCALE 4 */ + +/* sbrk for windows */ +static void *sbrk (long size) { + static long g_pagesize, g_my_pagesize; + static long g_regionsize, g_my_regionsize; + static region_list_entry *g_last; + void *result = (void *) MORECORE_FAILURE; +#ifdef TRACE + printf ("sbrk %d\n", size); +#endif +#if defined (USE_MALLOC_LOCK) && defined (NEEDED) + /* Wait for spin lock */ + slwait (&g_sl); +#endif + /* First time initialization */ + if (! g_pagesize) { + g_pagesize = getpagesize (); + g_my_pagesize = g_pagesize << SBRK_SCALE; + } + if (! g_regionsize) { + g_regionsize = getregionsize (); + g_my_regionsize = g_regionsize << SBRK_SCALE; + } + if (! g_last) { + if (! region_list_append (&g_last, 0, 0)) + goto sbrk_exit; + } + /* Assert invariants */ + assert (g_last); + assert ((char *) g_last->top_reserved - g_last->reserve_size <= (char *) g_last->top_allocated && + g_last->top_allocated <= g_last->top_committed); + assert ((char *) g_last->top_reserved - g_last->reserve_size <= (char *) g_last->top_committed && + g_last->top_committed <= g_last->top_reserved && + (unsigned) g_last->top_committed % g_pagesize == 0); + assert ((unsigned) g_last->top_reserved % g_regionsize == 0); + assert ((unsigned) g_last->reserve_size % g_regionsize == 0); + /* Allocation requested? */ + if (size >= 0) { + /* Allocation size is the requested size */ + long allocate_size = size; + /* Compute the size to commit */ + long to_commit = (char *) g_last->top_allocated + allocate_size - (char *) g_last->top_committed; + /* Do we reach the commit limit? */ + if (to_commit > 0) { + /* Round size to commit */ + long commit_size = CEIL (to_commit, g_my_pagesize); + /* Compute the size to reserve */ + long to_reserve = (char *) g_last->top_committed + commit_size - (char *) g_last->top_reserved; + /* Do we reach the reserve limit? */ + if (to_reserve > 0) { + /* Compute the remaining size to commit in the current region */ + long remaining_commit_size = (char *) g_last->top_reserved - (char *) g_last->top_committed; + if (remaining_commit_size > 0) { + /* Assert preconditions */ + assert ((unsigned) g_last->top_committed % g_pagesize == 0); + assert (0 < remaining_commit_size && remaining_commit_size % g_pagesize == 0); { + /* Commit this */ + void *base_committed = VirtualAlloc (g_last->top_committed, remaining_commit_size, + MEM_COMMIT, PAGE_READWRITE); + /* Check returned pointer for consistency */ + if (base_committed != g_last->top_committed) + goto sbrk_exit; + /* Assert postconditions */ + assert ((unsigned) base_committed % g_pagesize == 0); +#ifdef TRACE + printf ("Commit %p %d\n", base_committed, remaining_commit_size); +#endif + /* Adjust the regions commit top */ + g_last->top_committed = (char *) base_committed + remaining_commit_size; + } + } { + /* Now we are going to search and reserve. */ + int contiguous = -1; + int found = FALSE; + MEMORY_BASIC_INFORMATION memory_info; + void *base_reserved; + long reserve_size; + do { + /* Assume contiguous memory */ + contiguous = TRUE; + /* Round size to reserve */ + reserve_size = CEIL (to_reserve, g_my_regionsize); + /* Start with the current region's top */ + memory_info.BaseAddress = g_last->top_reserved; + /* Assert preconditions */ + assert ((unsigned) memory_info.BaseAddress % g_pagesize == 0); + assert (0 < reserve_size && reserve_size % g_regionsize == 0); + while (VirtualQuery (memory_info.BaseAddress, &memory_info, sizeof (memory_info))) { + /* Assert postconditions */ + assert ((unsigned) memory_info.BaseAddress % g_pagesize == 0); +#ifdef TRACE + printf ("Query %p %d %s\n", memory_info.BaseAddress, memory_info.RegionSize, + memory_info.State == MEM_FREE ? "FREE": + (memory_info.State == MEM_RESERVE ? "RESERVED": + (memory_info.State == MEM_COMMIT ? "COMMITTED": "?"))); +#endif + /* Region is free, well aligned and big enough: we are done */ + if (memory_info.State == MEM_FREE && + (unsigned) memory_info.BaseAddress % g_regionsize == 0 && + memory_info.RegionSize >= (unsigned) reserve_size) { + found = TRUE; + break; + } + /* From now on we can't get contiguous memory! */ + contiguous = FALSE; + /* Recompute size to reserve */ + reserve_size = CEIL (allocate_size, g_my_regionsize); + memory_info.BaseAddress = (char *) memory_info.BaseAddress + memory_info.RegionSize; + /* Assert preconditions */ + assert ((unsigned) memory_info.BaseAddress % g_pagesize == 0); + assert (0 < reserve_size && reserve_size % g_regionsize == 0); + } + /* Search failed? */ + if (! found) + goto sbrk_exit; + /* Assert preconditions */ + assert ((unsigned) memory_info.BaseAddress % g_regionsize == 0); + assert (0 < reserve_size && reserve_size % g_regionsize == 0); + /* Try to reserve this */ + base_reserved = VirtualAlloc (memory_info.BaseAddress, reserve_size, + MEM_RESERVE, PAGE_NOACCESS); + if (! base_reserved) { + int rc = GetLastError (); + if (rc != ERROR_INVALID_ADDRESS) + goto sbrk_exit; + } + /* A null pointer signals (hopefully) a race condition with another thread. */ + /* In this case, we try again. */ + } while (! base_reserved); + /* Check returned pointer for consistency */ + if (memory_info.BaseAddress && base_reserved != memory_info.BaseAddress) + goto sbrk_exit; + /* Assert postconditions */ + assert ((unsigned) base_reserved % g_regionsize == 0); +#ifdef TRACE + printf ("Reserve %p %d\n", base_reserved, reserve_size); +#endif + /* Did we get contiguous memory? */ + if (contiguous) { + long start_size = (char *) g_last->top_committed - (char *) g_last->top_allocated; + /* Adjust allocation size */ + allocate_size -= start_size; + /* Adjust the regions allocation top */ + g_last->top_allocated = g_last->top_committed; + /* Recompute the size to commit */ + to_commit = (char *) g_last->top_allocated + allocate_size - (char *) g_last->top_committed; + /* Round size to commit */ + commit_size = CEIL (to_commit, g_my_pagesize); + } + /* Append the new region to the list */ + if (! region_list_append (&g_last, base_reserved, reserve_size)) + goto sbrk_exit; + /* Didn't we get contiguous memory? */ + if (! contiguous) { + /* Recompute the size to commit */ + to_commit = (char *) g_last->top_allocated + allocate_size - (char *) g_last->top_committed; + /* Round size to commit */ + commit_size = CEIL (to_commit, g_my_pagesize); + } + } + } + /* Assert preconditions */ + assert ((unsigned) g_last->top_committed % g_pagesize == 0); + assert (0 < commit_size && commit_size % g_pagesize == 0); { + /* Commit this */ + void *base_committed = VirtualAlloc (g_last->top_committed, commit_size, + MEM_COMMIT, PAGE_READWRITE); + /* Check returned pointer for consistency */ + if (base_committed != g_last->top_committed) + goto sbrk_exit; + /* Assert postconditions */ + assert ((unsigned) base_committed % g_pagesize == 0); +#ifdef TRACE + printf ("Commit %p %d\n", base_committed, commit_size); +#endif + /* Adjust the regions commit top */ + g_last->top_committed = (char *) base_committed + commit_size; + } + } + /* Adjust the regions allocation top */ + g_last->top_allocated = (char *) g_last->top_allocated + allocate_size; + result = (char *) g_last->top_allocated - size; + /* Deallocation requested? */ + } else if (size < 0) { + long deallocate_size = - size; + /* As long as we have a region to release */ + while ((char *) g_last->top_allocated - deallocate_size < (char *) g_last->top_reserved - g_last->reserve_size) { + /* Get the size to release */ + long release_size = g_last->reserve_size; + /* Get the base address */ + void *base_reserved = (char *) g_last->top_reserved - release_size; + /* Assert preconditions */ + assert ((unsigned) base_reserved % g_regionsize == 0); + assert (0 < release_size && release_size % g_regionsize == 0); { + /* Release this */ + int rc = VirtualFree (base_reserved, 0, + MEM_RELEASE); + /* Check returned code for consistency */ + if (! rc) + goto sbrk_exit; +#ifdef TRACE + printf ("Release %p %d\n", base_reserved, release_size); +#endif + } + /* Adjust deallocation size */ + deallocate_size -= (char *) g_last->top_allocated - (char *) base_reserved; + /* Remove the old region from the list */ + if (! region_list_remove (&g_last)) + goto sbrk_exit; + } { + /* Compute the size to decommit */ + long to_decommit = (char *) g_last->top_committed - ((char *) g_last->top_allocated - deallocate_size); + if (to_decommit >= g_my_pagesize) { + /* Compute the size to decommit */ + long decommit_size = FLOOR (to_decommit, g_my_pagesize); + /* Compute the base address */ + void *base_committed = (char *) g_last->top_committed - decommit_size; + /* Assert preconditions */ + assert ((unsigned) base_committed % g_pagesize == 0); + assert (0 < decommit_size && decommit_size % g_pagesize == 0); { + /* Decommit this */ + int rc = VirtualFree ((char *) base_committed, decommit_size, + MEM_DECOMMIT); + /* Check returned code for consistency */ + if (! rc) + goto sbrk_exit; +#ifdef TRACE + printf ("Decommit %p %d\n", base_committed, decommit_size); +#endif + } + /* Adjust deallocation size and regions commit and allocate top */ + deallocate_size -= (char *) g_last->top_allocated - (char *) base_committed; + g_last->top_committed = base_committed; + g_last->top_allocated = base_committed; + } + } + /* Adjust regions allocate top */ + g_last->top_allocated = (char *) g_last->top_allocated - deallocate_size; + /* Check for underflow */ + if ((char *) g_last->top_reserved - g_last->reserve_size > (char *) g_last->top_allocated || + g_last->top_allocated > g_last->top_committed) { + /* Adjust regions allocate top */ + g_last->top_allocated = (char *) g_last->top_reserved - g_last->reserve_size; + goto sbrk_exit; + } + result = g_last->top_allocated; + } + /* Assert invariants */ + assert (g_last); + assert ((char *) g_last->top_reserved - g_last->reserve_size <= (char *) g_last->top_allocated && + g_last->top_allocated <= g_last->top_committed); + assert ((char *) g_last->top_reserved - g_last->reserve_size <= (char *) g_last->top_committed && + g_last->top_committed <= g_last->top_reserved && + (unsigned) g_last->top_committed % g_pagesize == 0); + assert ((unsigned) g_last->top_reserved % g_regionsize == 0); + assert ((unsigned) g_last->reserve_size % g_regionsize == 0); + +sbrk_exit: +#if defined (USE_MALLOC_LOCK) && defined (NEEDED) + /* Release spin lock */ + slrelease (&g_sl); +#endif + return result; +} + +/* mmap for windows */ +static void *mmap (void *ptr, long size, long prot, long type, long handle, long arg) { + static long g_pagesize; + static long g_regionsize; +#ifdef TRACE + printf ("mmap %d\n", size); +#endif +#if defined (USE_MALLOC_LOCK) && defined (NEEDED) + /* Wait for spin lock */ + slwait (&g_sl); +#endif + /* First time initialization */ + if (! g_pagesize) + g_pagesize = getpagesize (); + if (! g_regionsize) + g_regionsize = getregionsize (); + /* Assert preconditions */ + assert ((unsigned) ptr % g_regionsize == 0); + assert (size % g_pagesize == 0); + /* Allocate this */ + ptr = VirtualAlloc (ptr, size, + MEM_RESERVE | MEM_COMMIT | MEM_TOP_DOWN, PAGE_READWRITE); + if (! ptr) { + ptr = (void *) MORECORE_FAILURE; + goto mmap_exit; + } + /* Assert postconditions */ + assert ((unsigned) ptr % g_regionsize == 0); +#ifdef TRACE + printf ("Commit %p %d\n", ptr, size); +#endif +mmap_exit: +#if defined (USE_MALLOC_LOCK) && defined (NEEDED) + /* Release spin lock */ + slrelease (&g_sl); +#endif + return ptr; +} + +/* munmap for windows */ +static long munmap (void *ptr, long size) { + static long g_pagesize; + static long g_regionsize; + int rc = MUNMAP_FAILURE; +#ifdef TRACE + printf ("munmap %p %d\n", ptr, size); +#endif +#if defined (USE_MALLOC_LOCK) && defined (NEEDED) + /* Wait for spin lock */ + slwait (&g_sl); +#endif + /* First time initialization */ + if (! g_pagesize) + g_pagesize = getpagesize (); + if (! g_regionsize) + g_regionsize = getregionsize (); + /* Assert preconditions */ + assert ((unsigned) ptr % g_regionsize == 0); + assert (size % g_pagesize == 0); + /* Free this */ + if (! VirtualFree (ptr, 0, + MEM_RELEASE)) + goto munmap_exit; + rc = 0; +#ifdef TRACE + printf ("Release %p %d\n", ptr, size); +#endif +munmap_exit: +#if defined (USE_MALLOC_LOCK) && defined (NEEDED) + /* Release spin lock */ + slrelease (&g_sl); +#endif + return rc; +} + +static void vminfo (unsigned long *free, unsigned long *reserved, unsigned long *committed) { + MEMORY_BASIC_INFORMATION memory_info; + memory_info.BaseAddress = 0; + *free = *reserved = *committed = 0; + while (VirtualQuery (memory_info.BaseAddress, &memory_info, sizeof (memory_info))) { + switch (memory_info.State) { + case MEM_FREE: + *free += memory_info.RegionSize; + break; + case MEM_RESERVE: + *reserved += memory_info.RegionSize; + break; + case MEM_COMMIT: + *committed += memory_info.RegionSize; + break; + } + memory_info.BaseAddress = (char *) memory_info.BaseAddress + memory_info.RegionSize; + } +} + +static int cpuinfo (int whole, unsigned long *kernel, unsigned long *user) { + if (whole) { + __int64 creation64, exit64, kernel64, user64; + int rc = GetProcessTimes (GetCurrentProcess (), + (FILETIME *) &creation64, + (FILETIME *) &exit64, + (FILETIME *) &kernel64, + (FILETIME *) &user64); + if (! rc) { + *kernel = 0; + *user = 0; + return FALSE; + } + *kernel = (unsigned long) (kernel64 / 10000); + *user = (unsigned long) (user64 / 10000); + return TRUE; + } else { + __int64 creation64, exit64, kernel64, user64; + int rc = GetThreadTimes (GetCurrentThread (), + (FILETIME *) &creation64, + (FILETIME *) &exit64, + (FILETIME *) &kernel64, + (FILETIME *) &user64); + if (! rc) { + *kernel = 0; + *user = 0; + return FALSE; + } + *kernel = (unsigned long) (kernel64 / 10000); + *user = (unsigned long) (user64 / 10000); + return TRUE; + } +} + +#endif /* WIN32 */ + +/* + +History: + + V2.7.0 + * new WIN32 sbrk, mmap, munmap, lock code from <Walter@GeNeSys-e.de>. + * Allow override of MALLOC_ALIGNMENT (Thanks to Ruud Waij for + helping test this.) + * memalign: check alignment arg + * realloc: use memmove when regions may overlap. + * Collect all cases in malloc requiring system memory into sYSMALLOc + * Use mmap as backup to sbrk, if available; fold these mmap-related + operations into others. + * Place all internal state in malloc_state + * Introduce fastbins (although similar to 2.5.1) + * Many minor tunings and cosmetic improvements + * Introduce USE_PUBLIC_MALLOC_WRAPPERS, USE_MALLOC_LOCK + * Introduce MALLOC_FAILURE_ACTION, MORECORE_CONTIGUOUS + Thanks to Tony E. Bennett <tbennett@nvidia.com> and others. + * Adjust request2size to fit with MALLOC_FAILURE_ACTION. + * Include errno.h to support default failure action. + * Further improve WIN32 'sbrk()' emulation's 'findRegion()' routine + to avoid infinite loop when allocating initial memory larger + than RESERVED_SIZE and/or subsequent memory larger than + NEXT_SIZE. Thanks to Andreas Mueller <a.mueller at paradatec.de> + for finding this one. + + 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 at yahoo.com> + * Add 'LACKS_SYS_PARAM_H' for those systems without 'sys/param.h' + (e.g. WIN32 platforms) + * Cleanup 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.) + +*/ + + |