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/* Malloc implementation for multiple threads without lock contention. Copyright (C) 1996-2001, 2002 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Wolfram Gloger <wmglo@dent.med.uni-muenchen.de> and Doug Lea <dl@cs.oswego.edu>, 1996. The GNU C Library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. The GNU C Library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with the GNU C Library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. */ /* $Id: malloc.c 207 2010-07-19 17:43:24Z jeremybennett $ This work is mainly derived from malloc-2.6.4 by Doug Lea <dl@cs.oswego.edu>, which is available from: ftp://g.oswego.edu/pub/misc/malloc.c Most of the original comments are reproduced in the code below. * Why use this malloc? This is not the fastest, most space-conserving, most portable, or most tunable malloc ever written. However it is among the fastest while also being among the most space-conserving, portable and tunable. Consistent balance across these factors results in a good general-purpose allocator. For a high-level description, see http://g.oswego.edu/dl/html/malloc.html On many systems, the standard malloc implementation is by itself not thread-safe, and therefore wrapped with a single global lock around all malloc-related functions. In some applications, especially with multiple available processors, this can lead to contention problems and bad performance. This malloc version was designed with the goal to avoid waiting for locks as much as possible. Statistics indicate that this goal is achieved in many cases. * Synopsis of public routines (Much fuller descriptions are contained in the program documentation below.) ptmalloc_init(); Initialize global configuration. When compiled for multiple threads, this function must be called once before any other function in the package. It is not required otherwise. It is called automatically in the Linux/GNU C libray or when compiling with MALLOC_HOOKS. malloc(size_t n); Return a pointer to a newly allocated chunk of at least n bytes, or null if no space is available. free(Void_t* p); Release the chunk of memory pointed to by p, or no effect if p is null. realloc(Void_t* p, size_t n); Return a pointer to a chunk of size n that contains the same data as does chunk p up to the minimum of (n, p's size) bytes, or null if no space is available. The returned pointer may or may not be the same as p. If p is null, equivalent to malloc. Unless the #define REALLOC_ZERO_BYTES_FREES below is set, realloc with a size argument of zero (re)allocates a minimum-sized chunk. memalign(size_t alignment, size_t n); Return a pointer to a newly allocated chunk of n bytes, aligned in accord with the alignment argument, which must be a power of two. valloc(size_t n); Equivalent to memalign(pagesize, n), where pagesize is the page size of the system (or as near to this as can be figured out from all the includes/defines below.) pvalloc(size_t n); Equivalent to valloc(minimum-page-that-holds(n)), that is, round up n to nearest pagesize. calloc(size_t unit, size_t quantity); Returns a pointer to quantity * unit bytes, with all locations set to zero. cfree(Void_t* p); Equivalent to free(p). malloc_trim(size_t pad); Release all but pad bytes of freed top-most memory back to the system. Return 1 if successful, else 0. malloc_usable_size(Void_t* p); Report the number usable allocated bytes associated with allocated chunk p. This may or may not report more bytes than were requested, due to alignment and minimum size constraints. malloc_stats(); Prints brief summary statistics on stderr. mallinfo() Returns (by copy) a struct containing various summary statistics. mallopt(int parameter_number, int parameter_value) Changes one of the tunable parameters described below. Returns 1 if successful in changing the parameter, else 0. * Vital statistics: Alignment: 8-byte 8 byte alignment is currently hardwired into the design. This seems to suffice for all current machines and C compilers. Assumed pointer representation: 4 or 8 bytes Code for 8-byte pointers is untested by me but has worked reliably by Wolfram Gloger, who contributed most of the changes supporting this. Assumed size_t representation: 4 or 8 bytes Note that size_t is allowed to be 4 bytes even if pointers are 8. Minimum overhead per allocated chunk: 4 or 8 bytes Each malloced chunk has a hidden overhead of 4 bytes holding size and status information. Minimum allocated size: 4-byte ptrs: 16 bytes (including 4 overhead) 8-byte ptrs: 24/32 bytes (including, 4/8 overhead) When a chunk is freed, 12 (for 4byte ptrs) or 20 (for 8 byte ptrs but 4 byte size) or 24 (for 8/8) additional bytes are needed; 4 (8) for a trailing size field and 8 (16) bytes for free list pointers. Thus, the minimum allocatable size is 16/24/32 bytes. Even a request for zero bytes (i.e., malloc(0)) returns a pointer to something of the minimum allocatable size. Maximum allocated size: 4-byte size_t: 2^31 - 8 bytes 8-byte size_t: 2^63 - 16 bytes It is assumed that (possibly signed) size_t bit values suffice to represent chunk sizes. `Possibly signed' is due to the fact that `size_t' may be defined on a system as either a signed or an unsigned type. To be conservative, values that would appear as negative numbers are avoided. Requests for sizes with a negative sign bit will return a minimum-sized chunk. Maximum overhead wastage per allocated chunk: normally 15 bytes Alignment demands, plus the minimum allocatable size restriction make the normal worst-case wastage 15 bytes (i.e., up to 15 more bytes will be allocated than were requested in malloc), with two exceptions: 1. Because requests for zero bytes allocate non-zero space, the worst case wastage for a request of zero bytes is 24 bytes. 2. For requests >= mmap_threshold that are serviced via mmap(), the worst case wastage is 8 bytes plus the remainder from a system page (the minimal mmap unit); typically 4096 bytes. * Limitations Here are some features that are NOT currently supported * No automated mechanism for fully checking that all accesses to malloced memory stay within their bounds. * No support for compaction. * Synopsis of compile-time options: People have reported using previous versions of this malloc on all versions of Unix, sometimes by tweaking some of the defines below. It has been tested most extensively on Solaris and Linux. People have also reported adapting this malloc for use in stand-alone embedded systems. The implementation is in straight, hand-tuned ANSI C. Among other consequences, it uses a lot of macros. Because of this, to be at all usable, this code should be compiled using an optimizing compiler (for example gcc -O2) that can simplify expressions and control paths. __STD_C (default: derived from C compiler defines) Nonzero if using ANSI-standard C compiler, a C++ compiler, or a C compiler sufficiently close to ANSI to get away with it. MALLOC_DEBUG (default: NOT defined) Define to enable debugging. Adds fairly extensive assertion-based checking to help track down memory errors, but noticeably slows down execution. MALLOC_HOOKS (default: NOT defined) Define to enable support run-time replacement of the allocation functions through user-defined `hooks'. REALLOC_ZERO_BYTES_FREES (default: defined) Define this if you think that realloc(p, 0) should be equivalent to free(p). (The C standard requires this behaviour, therefore it is the default.) Otherwise, since malloc returns a unique pointer for malloc(0), so does realloc(p, 0). HAVE_MEMCPY (default: defined) Define if you are not otherwise using ANSI STD C, but still have memcpy and memset in your C library and want to use them. Otherwise, simple internal versions are supplied. USE_MEMCPY (default: 1 if HAVE_MEMCPY is defined, 0 otherwise) Define as 1 if you want the C library versions of memset and memcpy called in realloc and calloc (otherwise macro versions are used). At least on some platforms, the simple macro versions usually outperform libc versions. HAVE_MMAP (default: defined as 1) Define to non-zero to optionally make malloc() use mmap() to allocate very large blocks. HAVE_MREMAP (default: defined as 0 unless Linux libc set) Define to non-zero to optionally make realloc() use mremap() to reallocate very large blocks. USE_ARENAS (default: the same as HAVE_MMAP) Enable support for multiple arenas, allocated using mmap(). malloc_getpagesize (default: derived from system #includes) Either a constant or routine call returning the system page size. HAVE_USR_INCLUDE_MALLOC_H (default: NOT defined) Optionally define if you are on a system with a /usr/include/malloc.h that declares struct mallinfo. It is not at all necessary to define this even if you do, but will ensure consistency. INTERNAL_SIZE_T (default: size_t) Define to a 32-bit type (probably `unsigned int') if you are on a 64-bit machine, yet do not want or need to allow malloc requests of greater than 2^31 to be handled. This saves space, especially for very small chunks. _LIBC (default: NOT defined) Defined only when compiled as part of the Linux libc/glibc. Also note that there is some odd internal name-mangling via defines (for example, internally, `malloc' is named `mALLOc') needed when compiling in this case. These look funny but don't otherwise affect anything. LACKS_UNISTD_H (default: undefined) Define this if your system does not have a <unistd.h>. MORECORE (default: sbrk) The name of the routine to call to obtain more memory from the system. MORECORE_FAILURE (default: -1) The value returned upon failure of MORECORE. MORECORE_CLEARS (default 1) The degree to which the routine mapped to MORECORE zeroes out memory: never (0), only for newly allocated space (1) or always (2). The distinction between (1) and (2) is necessary because on some systems, if the application first decrements and then increments the break value, the contents of the reallocated space are unspecified. DEFAULT_TRIM_THRESHOLD DEFAULT_TOP_PAD DEFAULT_MMAP_THRESHOLD DEFAULT_MMAP_MAX Default values of tunable parameters (described in detail below) controlling interaction with host system routines (sbrk, mmap, etc). These values may also be changed dynamically via mallopt(). The preset defaults are those that give best performance for typical programs/systems. DEFAULT_CHECK_ACTION When the standard debugging hooks are in place, and a pointer is detected as corrupt, do nothing (0), print an error message (1), or call abort() (2). */ /* * Compile-time options for multiple threads: USE_PTHREADS, USE_THR, USE_SPROC Define one of these as 1 to select the thread interface: POSIX threads, Solaris threads or SGI sproc's, respectively. If none of these is defined as non-zero, you get a `normal' malloc implementation which is not thread-safe. Support for multiple threads requires HAVE_MMAP=1. As an exception, when compiling for GNU libc, i.e. when _LIBC is defined, then none of the USE_... symbols have to be defined. HEAP_MIN_SIZE HEAP_MAX_SIZE When thread support is enabled, additional `heap's are created with mmap calls. These are limited in size; HEAP_MIN_SIZE should be a multiple of the page size, while HEAP_MAX_SIZE must be a power of two for alignment reasons. HEAP_MAX_SIZE should be at least twice as large as the mmap threshold. THREAD_STATS When this is defined as non-zero, some statistics on mutex locking are computed. */ /* Preliminaries */ #ifndef __STD_C #if defined (__STDC__) #define __STD_C 1 #else #if __cplusplus #define __STD_C 1 #else #define __STD_C 0 #endif /*__cplusplus*/ #endif /*__STDC__*/ #endif /*__STD_C*/ #ifndef Void_t #if __STD_C #define Void_t void #else #define Void_t char #endif #endif /*Void_t*/ #define _GNU_SOURCE #include <features.h> #define _LIBC 1 #define NOT_IN_libc 1 #if __STD_C # include <stddef.h> /* for size_t */ # if defined _LIBC || defined MALLOC_HOOKS # include <stdlib.h> /* for getenv(), abort() */ # endif #else # include <sys/types.h> # if defined _LIBC || defined MALLOC_HOOKS extern char* getenv(); # endif #endif /* newlib modifications */ #include <libc-symbols.h> #include <sys/types.h> extern void __pthread_initialize (void) __attribute__((weak)); extern void *__mmap (void *__addr, size_t __len, int __prot, int __flags, int __fd, off_t __offset); extern int __munmap (void *__addr, size_t __len); extern void *__mremap (void *__addr, size_t __old_len, size_t __new_len, int __may_move); extern int __getpagesize (void); #define __libc_enable_secure 1 /* Macros for handling mutexes and thread-specific data. This is included early, because some thread-related header files (such as pthread.h) should be included before any others. */ #include <bits/libc-lock.h> #include "thread-m.h" void *(*__malloc_internal_tsd_get) (enum __libc_tsd_key_t) = NULL; int (*__malloc_internal_tsd_set) (enum __libc_tsd_key_t, __const void *) = NULL; weak_alias(__malloc_internal_tsd_get, __libc_internal_tsd_get) weak_alias(__malloc_internal_tsd_set, __libc_internal_tsd_set) #ifdef __cplusplus extern "C" { #endif #include <errno.h> #include <stdio.h> /* needed for malloc_stats */ /* Compile-time options */ /* Debugging: Because freed chunks may be overwritten with link fields, this malloc will often die when freed memory is overwritten by user programs. This can be very effective (albeit in an annoying way) in helping track down dangling pointers. If you compile with -DMALLOC_DEBUG, 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 MALLOC_DEBUG set will attempt to check every non-mmapped allocated and free chunk in the course of computing the summaries. (By nature, mmapped regions cannot be checked very much automatically.) Setting MALLOC_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 MALLOC_DEBUG #include <assert.h> #else #define assert(x) ((void)0) #endif /* INTERNAL_SIZE_T is the word-size used for internal bookkeeping of chunk sizes. On a 64-bit machine, you can reduce malloc overhead by defining INTERNAL_SIZE_T to be a 32 bit `unsigned int' at the expense of not being able to handle requests greater than 2^31. This limitation is hardly ever a concern; you are encouraged to set this. However, the default version is the same as size_t. */ #ifndef INTERNAL_SIZE_T #define INTERNAL_SIZE_T size_t #endif /* REALLOC_ZERO_BYTES_FREES should be set if a call to realloc with zero bytes should be the same as a call to free. The C standard requires this. Otherwise, since this malloc returns a unique pointer for malloc(0), so does realloc(p, 0). */ #define REALLOC_ZERO_BYTES_FREES /* HAVE_MEMCPY should be defined if you are not otherwise using ANSI STD C, but still have memcpy and memset in your C library and want to use them in calloc and realloc. Otherwise simple macro versions are defined here. USE_MEMCPY should be defined as 1 if you actually want to have memset and memcpy called. People report that the macro versions are often enough faster than libc versions on many systems that it is better to use them. */ #define HAVE_MEMCPY 1 #ifndef USE_MEMCPY #ifdef HAVE_MEMCPY #define USE_MEMCPY 1 #else #define USE_MEMCPY 0 #endif #endif #if (__STD_C || defined(HAVE_MEMCPY)) #if __STD_C void* memset(void*, int, size_t); void* memcpy(void*, const void*, size_t); void* memmove(void*, const void*, size_t); #else Void_t* memset(); Void_t* memcpy(); Void_t* memmove(); #endif #endif /* The following macros are only invoked with (2n+1)-multiples of INTERNAL_SIZE_T units, with a positive integer n. This is exploited for fast inline execution when n is small. If the regions to be copied do overlap, the destination lies always _below_ the source. */ #if USE_MEMCPY #define MALLOC_ZERO(charp, nbytes) \ do { \ INTERNAL_SIZE_T mzsz = (nbytes); \ if(mzsz <= 9*sizeof(mzsz)) { \ INTERNAL_SIZE_T* mz = (INTERNAL_SIZE_T*) (charp); \ if(mzsz >= 5*sizeof(mzsz)) { *mz++ = 0; \ *mz++ = 0; \ if(mzsz >= 7*sizeof(mzsz)) { *mz++ = 0; \ *mz++ = 0; \ if(mzsz >= 9*sizeof(mzsz)) { *mz++ = 0; \ *mz++ = 0; }}} \ *mz++ = 0; \ *mz++ = 0; \ *mz = 0; \ } else memset((charp), 0, mzsz); \ } while(0) /* If the regions overlap, dest is always _below_ src. */ #define MALLOC_COPY(dest,src,nbytes,overlap) \ do { \ INTERNAL_SIZE_T mcsz = (nbytes); \ if(mcsz <= 9*sizeof(mcsz)) { \ INTERNAL_SIZE_T* mcsrc = (INTERNAL_SIZE_T*) (src); \ INTERNAL_SIZE_T* mcdst = (INTERNAL_SIZE_T*) (dest); \ if(mcsz >= 5*sizeof(mcsz)) { *mcdst++ = *mcsrc++; \ *mcdst++ = *mcsrc++; \ if(mcsz >= 7*sizeof(mcsz)) { *mcdst++ = *mcsrc++; \ *mcdst++ = *mcsrc++; \ if(mcsz >= 9*sizeof(mcsz)) { *mcdst++ = *mcsrc++; \ *mcdst++ = *mcsrc++; }}} \ *mcdst++ = *mcsrc++; \ *mcdst++ = *mcsrc++; \ *mcdst = *mcsrc ; \ } else if(overlap) \ memmove(dest, src, mcsz); \ else \ memcpy(dest, src, mcsz); \ } while(0) #else /* !USE_MEMCPY */ /* Use Duff's device for good zeroing/copying performance. */ #define MALLOC_ZERO(charp, nbytes) \ do { \ INTERNAL_SIZE_T* mzp = (INTERNAL_SIZE_T*)(charp); \ long mctmp = (nbytes)/sizeof(INTERNAL_SIZE_T), mcn; \ if (mctmp < 8) mcn = 0; else { mcn = (mctmp-1)/8; mctmp %= 8; } \ switch (mctmp) { \ case 0: for(;;) { *mzp++ = 0; \ case 7: *mzp++ = 0; \ case 6: *mzp++ = 0; \ case 5: *mzp++ = 0; \ case 4: *mzp++ = 0; \ case 3: *mzp++ = 0; \ case 2: *mzp++ = 0; \ case 1: *mzp++ = 0; if(mcn <= 0) break; mcn--; } \ } \ } while(0) /* If the regions overlap, 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 #ifndef LACKS_UNISTD_H # include <unistd.h> #endif /* Define HAVE_MMAP to optionally make malloc() use mmap() to allocate very large blocks. These will be returned to the operating system immediately after a free(). HAVE_MMAP is also a prerequisite to support multiple `arenas' (see USE_ARENAS below). */ #ifndef HAVE_MMAP # ifdef _POSIX_MAPPED_FILES # define HAVE_MMAP 1 # endif #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 #define HAVE_MREMAP defined(__linux__) #endif /* Define USE_ARENAS to enable support for multiple `arenas'. These are allocated using mmap(), are necessary for threads and occasionally useful to overcome address space limitations affecting sbrk(). */ #ifndef USE_ARENAS #define USE_ARENAS HAVE_MMAP #endif #if HAVE_MMAP #include <unistd.h> #include <fcntl.h> #include <sys/mman.h> #if !defined(MAP_ANONYMOUS) && defined(MAP_ANON) #define MAP_ANONYMOUS MAP_ANON #endif #if !defined(MAP_FAILED) #define MAP_FAILED ((char*)-1) #endif #ifndef MAP_NORESERVE # ifdef MAP_AUTORESRV # define MAP_NORESERVE MAP_AUTORESRV # else # define MAP_NORESERVE 0 # endif #endif #endif /* HAVE_MMAP */ /* Access to system page size. To the extent possible, this malloc manages memory from the system in page-size units. The following mechanics for getpagesize were adapted from bsd/gnu getpagesize.h */ #ifndef malloc_getpagesize # ifdef _SC_PAGESIZE /* some SVR4 systems omit an underscore */ # ifndef _SC_PAGE_SIZE # define _SC_PAGE_SIZE _SC_PAGESIZE # endif # endif # ifdef _SC_PAGE_SIZE # define malloc_getpagesize sysconf(_SC_PAGE_SIZE) # else # if defined(BSD) || defined(DGUX) || defined(HAVE_GETPAGESIZE) extern size_t getpagesize(); # define malloc_getpagesize getpagesize() # else # include <sys/param.h> # ifdef EXEC_PAGESIZE # define malloc_getpagesize EXEC_PAGESIZE # else # ifdef NBPG # ifndef CLSIZE # define malloc_getpagesize NBPG # else # define malloc_getpagesize (NBPG * CLSIZE) # endif # else # ifdef NBPC # define malloc_getpagesize NBPC # else # ifdef PAGESIZE # define malloc_getpagesize PAGESIZE # else # define malloc_getpagesize (4096) /* just guess */ # endif # endif # endif # endif # endif # endif #endif /* This version of malloc supports the standard SVID/XPG mallinfo routine that returns a struct containing the same kind of information you can get from malloc_stats. It should work on any SVID/XPG compliant system that has a /usr/include/malloc.h defining struct mallinfo. (If you'd like to install such a thing yourself, cut out the preliminary declarations as described above and below and save them in a malloc.h file. But there's no compelling reason to bother to do this.) The main declaration needed is the mallinfo struct that is returned (by-copy) by mallinfo(). The SVID/XPG malloinfo struct contains a bunch of fields, most of which are not even meaningful in this version of malloc. Some of these fields are are instead filled by mallinfo() with other numbers that might possibly be of interest. HAVE_USR_INCLUDE_MALLOC_H should be set if you have a /usr/include/malloc.h file that includes a declaration of struct mallinfo. If so, it is included; else an SVID2/XPG2 compliant version is declared below. These must be precisely the same for mallinfo() to work. */ /* #define HAVE_USR_INCLUDE_MALLOC_H */ #if HAVE_USR_INCLUDE_MALLOC_H # include "/usr/include/malloc.h" #else # ifdef _LIBC # include "malloc.h" # else # include "ptmalloc.h" # endif #endif #include <bp-checks.h> #ifndef DEFAULT_TRIM_THRESHOLD #define DEFAULT_TRIM_THRESHOLD (128 * 1024) #endif /* M_TRIM_THRESHOLD is the maximum amount of unused top-most memory to keep before releasing via malloc_trim in free(). Automatic trimming is mainly useful in long-lived programs. Because trimming via sbrk can be slow on some systems, and can sometimes be wasteful (in cases where programs immediately afterward allocate more large chunks) the value should be high enough so that your overall system performance would improve by releasing. The trim threshold and the mmap control parameters (see below) can be traded off with one another. Trimming and mmapping are two different ways of releasing unused memory back to the system. Between these two, it is often possible to keep system-level demands of a long-lived program down to a bare minimum. For example, in one test suite of sessions measuring the XF86 X server on Linux, using a trim threshold of 128K and a mmap threshold of 192K led to near-minimal long term resource consumption. If you are using this malloc in a long-lived program, it should pay to experiment with these values. As a rough guide, you might set to a value close to the average size of a process (program) running on your system. Releasing this much memory would allow such a process to run in memory. Generally, it's worth it to tune for trimming rather than memory mapping when a program undergoes phases where several large chunks are allocated and released in ways that can reuse each other's storage, perhaps mixed with phases where there are no such chunks at all. And in well-behaved long-lived programs, controlling release of large blocks via trimming versus mapping is usually faster. However, in most programs, these parameters serve mainly as protection against the system-level effects of carrying around massive amounts of unneeded memory. Since frequent calls to sbrk, mmap, and munmap otherwise degrade performance, the default parameters are set to relatively high values that serve only as safeguards. The default trim value is high enough to cause trimming only in fairly extreme (by current memory consumption standards) cases. It must be greater than page size to have any useful effect. To disable trimming completely, you can set to (unsigned long)(-1); */ #ifndef DEFAULT_TOP_PAD #define DEFAULT_TOP_PAD (0) #endif /* M_TOP_PAD is the amount of extra `padding' space to allocate or retain whenever sbrk is called. It is used in two ways internally: * When sbrk is called to extend the top of the arena to satisfy a new malloc request, this much padding is added to the sbrk request. * When malloc_trim is called automatically from free(), it is used as the `pad' argument. In both cases, the actual amount of padding is rounded so that the end of the arena is always a system page boundary. The main reason for using padding is to avoid calling sbrk so often. Having even a small pad greatly reduces the likelihood that nearly every malloc request during program start-up (or after trimming) will invoke sbrk, which needlessly wastes time. Automatic rounding-up to page-size units is normally sufficient to avoid measurable overhead, so the default is 0. However, in systems where sbrk is relatively slow, it can pay to increase this value, at the expense of carrying around more memory than the program needs. */ #ifndef DEFAULT_MMAP_THRESHOLD #define DEFAULT_MMAP_THRESHOLD (128 * 1024) #endif /* M_MMAP_THRESHOLD is the request size threshold for using mmap() to service a request. Requests of at least this size that cannot be allocated using already-existing space will be serviced via mmap. (If enough normal freed space already exists it is used instead.) Using mmap segregates relatively large chunks of memory so that they can be individually obtained and released from the host system. A request serviced through mmap is never reused by any other request (at least not directly; the system may just so happen to remap successive requests to the same locations). Segregating space in this way has the benefit that mmapped space can ALWAYS be individually released back to the system, which helps keep the system level memory demands of a long-lived program low. Mapped memory can never become `locked' between other chunks, as can happen with normally allocated chunks, which menas that even trimming via malloc_trim would not release them. However, it has the disadvantages that: 1. The space cannot be reclaimed, consolidated, and then used to service later requests, as happens with normal chunks. 2. It can lead to more wastage because of mmap page alignment requirements 3. It causes malloc performance to be more dependent on host system memory management support routines which may vary in implementation quality and may impose arbitrary limitations. Generally, servicing a request via normal malloc steps is faster than going through a system's mmap. All together, these considerations should lead you to use mmap only for relatively large requests. */ #ifndef DEFAULT_MMAP_MAX #if HAVE_MMAP #define DEFAULT_MMAP_MAX (1024) #else #define DEFAULT_MMAP_MAX (0) #endif #endif /* M_MMAP_MAX is the maximum number of requests to simultaneously service using mmap. This parameter exists because: 1. Some systems have a limited number of internal tables for use by mmap. 2. In most systems, overreliance on mmap can degrade overall performance. 3. If a program allocates many large regions, it is probably better off using normal sbrk-based allocation routines that can reclaim and reallocate normal heap memory. Using a small value allows transition into this mode after the first few allocations. Setting to 0 disables all use of mmap. If HAVE_MMAP is not set, the default value is 0, and attempts to set it to non-zero values in mallopt will fail. */ #ifndef DEFAULT_CHECK_ACTION #define DEFAULT_CHECK_ACTION 1 #endif /* What to do if the standard debugging hooks are in place and a corrupt pointer is detected: do nothing (0), print an error message (1), or call abort() (2). */ #define HEAP_MIN_SIZE (32*1024) #define HEAP_MAX_SIZE (1024*1024) /* must be a power of two */ /* HEAP_MIN_SIZE and HEAP_MAX_SIZE limit the size of mmap()ed heaps that are dynamically created for multi-threaded programs. The maximum size must be a power of two, for fast determination of which heap belongs to a chunk. It should be much larger than the mmap threshold, so that requests with a size just below that threshold can be fulfilled without creating too many heaps. */ #ifndef THREAD_STATS #define THREAD_STATS 0 #endif /* If THREAD_STATS is non-zero, some statistics on mutex locking are computed. */ /* Macro to set errno. */ #ifndef __set_errno # define __set_errno(val) errno = (val) #endif /* On some platforms we can compile internal, not exported functions better. Let the environment provide a macro and define it to be empty if it is not available. */ #ifndef internal_function # define internal_function #endif /* Special defines for the Linux/GNU C library. */ #ifdef _LIBC #if __STD_C Void_t * __default_morecore (ptrdiff_t); Void_t *(*__morecore)(ptrdiff_t) = __default_morecore; #else Void_t * __default_morecore (); Void_t *(*__morecore)() = __default_morecore; #endif #define MORECORE (*__morecore) #define MORECORE_FAILURE 0 #ifndef MORECORE_CLEARS #define MORECORE_CLEARS 1 #endif static size_t __libc_pagesize; #define access __access #define mmap __mmap #define munmap __munmap #define mremap __mremap #define mprotect __mprotect #undef malloc_getpagesize #define malloc_getpagesize __libc_pagesize #else /* _LIBC */ #if __STD_C extern Void_t* sbrk(ptrdiff_t); #else extern Void_t* sbrk(); #endif #ifndef MORECORE #define MORECORE sbrk #endif #ifndef MORECORE_FAILURE #define MORECORE_FAILURE -1 #endif #ifndef MORECORE_CLEARS #define MORECORE_CLEARS 1 #endif #endif /* _LIBC */ #ifdef _LIBC #define cALLOc __libc_calloc #define fREe __libc_free #define mALLOc __libc_malloc #define mEMALIGn __libc_memalign #define rEALLOc __libc_realloc #define vALLOc __libc_valloc #define pvALLOc __libc_pvalloc #define mALLINFo __libc_mallinfo #define mALLOPt __libc_mallopt #define mALLOC_STATs __malloc_stats #define mALLOC_USABLE_SIZe __malloc_usable_size #define mALLOC_TRIm __malloc_trim #define mALLOC_GET_STATe __malloc_get_state #define mALLOC_SET_STATe __malloc_set_state #else #define cALLOc calloc #define fREe free #define mALLOc malloc #define mEMALIGn memalign #define rEALLOc realloc #define vALLOc valloc #define pvALLOc pvalloc #define mALLINFo mallinfo #define mALLOPt mallopt #define mALLOC_STATs malloc_stats #define mALLOC_USABLE_SIZe malloc_usable_size #define mALLOC_TRIm malloc_trim #define mALLOC_GET_STATe malloc_get_state #define mALLOC_SET_STATe malloc_set_state #endif /* Public routines */ #if __STD_C #ifndef _LIBC void ptmalloc_init(void); #endif Void_t* mALLOc(size_t); void fREe(Void_t*); Void_t* rEALLOc(Void_t*, size_t); Void_t* mEMALIGn(size_t, size_t); Void_t* vALLOc(size_t); Void_t* pvALLOc(size_t); Void_t* cALLOc(size_t, size_t); void cfree(Void_t*); int mALLOC_TRIm(size_t); size_t mALLOC_USABLE_SIZe(Void_t*); void mALLOC_STATs(void); int mALLOPt(int, int); struct mallinfo mALLINFo(void); Void_t* mALLOC_GET_STATe(void); int mALLOC_SET_STATe(Void_t*); #else /* !__STD_C */ #ifndef _LIBC void ptmalloc_init(); #endif Void_t* mALLOc(); void fREe(); Void_t* rEALLOc(); Void_t* mEMALIGn(); Void_t* vALLOc(); Void_t* pvALLOc(); Void_t* cALLOc(); void cfree(); int mALLOC_TRIm(); size_t mALLOC_USABLE_SIZe(); void mALLOC_STATs(); int mALLOPt(); struct mallinfo mALLINFo(); Void_t* mALLOC_GET_STATe(); int mALLOC_SET_STATe(); #endif /* __STD_C */ #ifdef __cplusplus } /* end of extern "C" */ #endif #if !defined(NO_THREADS) && !HAVE_MMAP "Can't have threads support without mmap" #endif #if USE_ARENAS && !HAVE_MMAP "Can't have multiple arenas without mmap" #endif /* Type declarations */ struct malloc_chunk { INTERNAL_SIZE_T prev_size; /* Size of previous chunk (if free). */ INTERNAL_SIZE_T size; /* Size in bytes, including overhead. */ struct malloc_chunk* fd; /* double links -- used only if free. */ struct malloc_chunk* bk; }; typedef struct malloc_chunk* mchunkptr; /* malloc_chunk details: (The following includes lightly edited explanations by Colin Plumb.) Chunks of memory are maintained using a `boundary tag' method as described in e.g., Knuth or Standish. (See the paper by Paul Wilson ftp://ftp.cs.utexas.edu/pub/garbage/allocsrv.ps for a survey of such techniques.) Sizes of free chunks are stored both in the front of each chunk and at the end. This makes consolidating fragmented chunks into bigger chunks very fast. The size fields also hold bits representing whether chunks are free or in use. An allocated chunk looks like this: chunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Size of previous chunk, if allocated | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Size of chunk, in bytes |P| mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | User data starts here... . . . . (malloc_usable_space() bytes) . . | nextchunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Size of chunk | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Where "chunk" is the front of the chunk for the purpose of most of the malloc code, but "mem" is the pointer that is returned to the user. "Nextchunk" is the beginning of the next contiguous chunk. Chunks always begin on even word boundaries, so the mem portion (which is returned to the user) is also on an even word boundary, and thus double-word aligned. Free chunks are stored in circular doubly-linked lists, and look like this: chunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Size of previous chunk | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ `head:' | Size of chunk, in bytes |P| mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Forward pointer to next chunk in list | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Back pointer to previous chunk in list | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Unused space (may be 0 bytes long) . . . . | nextchunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ `foot:' | Size of chunk, in bytes | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ The P (PREV_INUSE) bit, stored in the unused low-order bit of the chunk size (which is always a multiple of two words), is an in-use bit for the *previous* chunk. If that bit is *clear*, then the word before the current chunk size contains the previous chunk size, and can be used to find the front of the previous chunk. (The very first chunk allocated always has this bit set, preventing access to non-existent (or non-owned) memory.) Note that the `foot' of the current chunk is actually represented as the prev_size of the NEXT chunk. (This makes it easier to deal with alignments etc). The two exceptions to all this are 1. The special chunk `top', which doesn't bother using the trailing size field since there is no next contiguous chunk that would have to index off it. (After initialization, `top' is forced to always exist. If it would become less than MINSIZE bytes long, it is replenished via malloc_extend_top.) 2. Chunks allocated via mmap, which have the second-lowest-order bit (IS_MMAPPED) set in their size fields. Because they are never merged or traversed from any other chunk, they have no foot size or inuse information. Available chunks are kept in any of several places (all declared below): * `av': An array of chunks serving as bin headers for consolidated chunks. Each bin is doubly linked. The bins are approximately proportionally (log) spaced. There are a lot of these bins (128). This may look excessive, but works very well in practice. All procedures maintain the invariant that no consolidated chunk physically borders another one. Chunks in bins are kept in size order, with ties going to the approximately least recently used chunk. The chunks in each bin are maintained in decreasing sorted order by size. This is irrelevant for the small bins, which all contain the same-sized chunks, but facilitates best-fit allocation for larger chunks. (These lists are just sequential. Keeping them in order almost never requires enough traversal to warrant using fancier ordered data structures.) Chunks of the same size are linked with the most recently freed at the front, and allocations are taken from the back. This results in LRU or FIFO allocation order, which tends to give each chunk an equal opportunity to be consolidated with adjacent freed chunks, resulting in larger free chunks and less fragmentation. * `top': The top-most available chunk (i.e., the one bordering the end of available memory) is treated specially. It is never included in any bin, is used only if no other chunk is available, and is released back to the system if it is very large (see M_TRIM_THRESHOLD). * `last_remainder': A bin holding only the remainder of the most recently split (non-top) chunk. This bin is checked before other non-fitting chunks, so as to provide better locality for runs of sequentially allocated chunks. * Implicitly, through the host system's memory mapping tables. If supported, requests greater than a threshold are usually serviced via calls to mmap, and then later released via munmap. */ /* Bins The bins are an array of pairs of pointers serving as the heads of (initially empty) doubly-linked lists of chunks, laid out in a way so that each pair can be treated as if it were in a malloc_chunk. (This way, the fd/bk offsets for linking bin heads and chunks are the same). Bins for sizes < 512 bytes contain chunks of all the same size, spaced 8 bytes apart. Larger bins are approximately logarithmically spaced. (See the table below.) Bin layout: 64 bins of size 8 32 bins of size 64 16 bins of size 512 8 bins of size 4096 4 bins of size 32768 2 bins of size 262144 1 bin of size what's left There is actually a little bit of slop in the numbers in bin_index for the sake of speed. This makes no difference elsewhere. The special chunks `top' and `last_remainder' get their own bins, (this is implemented via yet more trickery with the av array), although `top' is never properly linked to its bin since it is always handled specially. */ #define NAV 128 /* number of bins */ typedef struct malloc_chunk* mbinptr; /* An arena is a configuration of malloc_chunks together with an array of bins. With multiple threads, it must be locked via a mutex before changing its data structures. One or more `heaps' are associated with each arena, except for the main_arena, which is associated only with the `main heap', i.e. the conventional free store obtained with calls to MORECORE() (usually sbrk). The `av' array is never mentioned directly in the code, but instead used via bin access macros. */ typedef struct _arena { mbinptr av[2*NAV + 2]; struct _arena *next; size_t size; #if THREAD_STATS long stat_lock_direct, stat_lock_loop, stat_lock_wait; #endif mutex_t mutex; } arena; /* A heap is a single contiguous memory region holding (coalesceable) malloc_chunks. It is allocated with mmap() and always starts at an address aligned to HEAP_MAX_SIZE. Not used unless compiling with USE_ARENAS. */ typedef struct _heap_info { arena *ar_ptr; /* Arena for this heap. */ struct _heap_info *prev; /* Previous heap. */ size_t size; /* Current size in bytes. */ size_t pad; /* Make sure the following data is properly aligned. */ } heap_info; /* Static functions (forward declarations) */ #if __STD_C static void chunk_free(arena *ar_ptr, mchunkptr p) internal_function; static mchunkptr chunk_alloc(arena *ar_ptr, INTERNAL_SIZE_T size) internal_function; static mchunkptr chunk_realloc(arena *ar_ptr, mchunkptr oldp, INTERNAL_SIZE_T oldsize, INTERNAL_SIZE_T nb) internal_function; static mchunkptr chunk_align(arena *ar_ptr, INTERNAL_SIZE_T nb, size_t alignment) internal_function; static int main_trim(size_t pad) internal_function; #if USE_ARENAS static int heap_trim(heap_info *heap, size_t pad) internal_function; #endif #if defined _LIBC || defined MALLOC_HOOKS static Void_t* malloc_check(size_t sz, const Void_t *caller); static void free_check(Void_t* mem, const Void_t *caller); static Void_t* realloc_check(Void_t* oldmem, size_t bytes, const Void_t *caller); static Void_t* memalign_check(size_t alignment, size_t bytes, const Void_t *caller); #ifndef NO_THREADS static Void_t* malloc_starter(size_t sz, const Void_t *caller); static void free_starter(Void_t* mem, const Void_t *caller); static Void_t* malloc_atfork(size_t sz, const Void_t *caller); static void free_atfork(Void_t* mem, const Void_t *caller); #endif #endif #else static void chunk_free(); static mchunkptr chunk_alloc(); static mchunkptr chunk_realloc(); static mchunkptr chunk_align(); static int main_trim(); #if USE_ARENAS static int heap_trim(); #endif #if defined _LIBC || defined MALLOC_HOOKS static Void_t* malloc_check(); static void free_check(); static Void_t* realloc_check(); static Void_t* memalign_check(); #ifndef NO_THREADS static Void_t* malloc_starter(); static void free_starter(); static Void_t* malloc_atfork(); static void free_atfork(); #endif #endif #endif /* sizes, alignments */ #define SIZE_SZ (sizeof(INTERNAL_SIZE_T)) /* Allow the default to be overwritten on the compiler command line. */ #ifndef MALLOC_ALIGNMENT # define MALLOC_ALIGNMENT (SIZE_SZ + SIZE_SZ) #endif #define MALLOC_ALIGN_MASK (MALLOC_ALIGNMENT - 1) #define MINSIZE (sizeof(struct malloc_chunk)) /* conversion from malloc headers to user pointers, and back */ #define chunk2mem(p) ((Void_t*)((char*)(p) + 2*SIZE_SZ)) #define mem2chunk(mem) chunk_at_offset((mem), -2*SIZE_SZ) /* pad request bytes into a usable size, return non-zero on overflow */ #define request2size(req, nb) \ ((nb = (req) + (SIZE_SZ + MALLOC_ALIGN_MASK)),\ ((long)nb <= 0 || nb < (INTERNAL_SIZE_T) (req) \ ? (__set_errno (ENOMEM), 1) \ : ((nb < (MINSIZE + MALLOC_ALIGN_MASK) \ ? (nb = MINSIZE) : (nb &= ~MALLOC_ALIGN_MASK)), 0))) /* Check if m has acceptable alignment */ #define aligned_OK(m) (((unsigned long)((m)) & (MALLOC_ALIGN_MASK)) == 0) /* Physical chunk operations */ /* size field is or'ed with PREV_INUSE when previous adjacent chunk in use */ #define PREV_INUSE 0x1UL /* size field is or'ed with IS_MMAPPED if the chunk was obtained with mmap() */ #define IS_MMAPPED 0x2UL /* Bits to mask off when extracting size */ #define SIZE_BITS (PREV_INUSE|IS_MMAPPED) /* Ptr to next physical malloc_chunk. */ #define next_chunk(p) chunk_at_offset((p), (p)->size & ~PREV_INUSE) /* Ptr to previous physical malloc_chunk */ #define prev_chunk(p) chunk_at_offset((p), -(p)->prev_size) /* Treat space at ptr + offset as a chunk */ #define chunk_at_offset(p, s) BOUNDED_1((mchunkptr)(((char*)(p)) + (s))) /* Dealing with use bits */ /* extract p's inuse bit */ #define inuse(p) (next_chunk(p)->size & PREV_INUSE) /* extract inuse bit of previous chunk */ #define prev_inuse(p) ((p)->size & PREV_INUSE) /* check for mmap()'ed chunk */ #define chunk_is_mmapped(p) ((p)->size & IS_MMAPPED) /* set/clear chunk as in use without otherwise disturbing */ #define set_inuse(p) (next_chunk(p)->size |= PREV_INUSE) #define clear_inuse(p) (next_chunk(p)->size &= ~PREV_INUSE) /* check/set/clear inuse bits in known places */ #define inuse_bit_at_offset(p, s) \ (chunk_at_offset((p), (s))->size & PREV_INUSE) #define set_inuse_bit_at_offset(p, s) \ (chunk_at_offset((p), (s))->size |= PREV_INUSE) #define clear_inuse_bit_at_offset(p, s) \ (chunk_at_offset((p), (s))->size &= ~(PREV_INUSE)) /* Dealing with size fields */ /* Get size, ignoring use bits */ #define chunksize(p) ((p)->size & ~(SIZE_BITS)) /* Set size at head, without disturbing its use bit */ #define set_head_size(p, s) ((p)->size = (((p)->size & PREV_INUSE) | (s))) /* Set size/use ignoring previous bits in header */ #define set_head(p, s) ((p)->size = (s)) /* Set size at footer (only when chunk is not in use) */ #define set_foot(p, s) (chunk_at_offset(p, s)->prev_size = (s)) /* access macros */ #define bin_at(a, i) BOUNDED_1(_bin_at(a, i)) #define _bin_at(a, i) ((mbinptr)((char*)&(((a)->av)[2*(i)+2]) - 2*SIZE_SZ)) #define init_bin(a, i) ((a)->av[2*(i)+2] = (a)->av[2*(i)+3] = bin_at((a), (i))) #define next_bin(b) ((mbinptr)((char*)(b) + 2 * sizeof(((arena*)0)->av[0]))) #define prev_bin(b) ((mbinptr)((char*)(b) - 2 * sizeof(((arena*)0)->av[0]))) /* The first 2 bins are never indexed. The corresponding av cells are instead used for bookkeeping. This is not to save space, but to simplify indexing, maintain locality, and avoid some initialization tests. */ #define binblocks(a) (bin_at(a,0)->size)/* bitvector of nonempty blocks */ #define top(a) (bin_at(a,0)->fd) /* The topmost chunk */ #define last_remainder(a) (bin_at(a,1)) /* remainder from last split */ /* Because top initially points to its own bin with initial zero size, thus forcing extension on the first malloc request, we avoid having any special code in malloc to check whether it even exists yet. But we still need to in malloc_extend_top. */ #define initial_top(a) ((mchunkptr)bin_at(a, 0)) /* field-extraction macros */ #define first(b) ((b)->fd) #define last(b) ((b)->bk) /* Indexing into bins */ #define bin_index(sz) \ (((((unsigned long)(sz)) >> 9) == 0) ? (((unsigned long)(sz)) >> 3):\ ((((unsigned long)(sz)) >> 9) <= 4) ? 56 + (((unsigned long)(sz)) >> 6):\ ((((unsigned long)(sz)) >> 9) <= 20) ? 91 + (((unsigned long)(sz)) >> 9):\ ((((unsigned long)(sz)) >> 9) <= 84) ? 110 + (((unsigned long)(sz)) >> 12):\ ((((unsigned long)(sz)) >> 9) <= 340) ? 119 + (((unsigned long)(sz)) >> 15):\ ((((unsigned long)(sz)) >> 9) <= 1364) ? 124 + (((unsigned long)(sz)) >> 18):\ 126) /* bins for chunks < 512 are all spaced 8 bytes apart, and hold identically sized chunks. This is exploited in malloc. */ #define MAX_SMALLBIN 63 #define MAX_SMALLBIN_SIZE 512 #define SMALLBIN_WIDTH 8 #define smallbin_index(sz) (((unsigned long)(sz)) >> 3) /* Requests are `small' if both the corresponding and the next bin are small */ #define is_small_request(nb) ((nb) < MAX_SMALLBIN_SIZE - SMALLBIN_WIDTH) /* To help compensate for the large number of bins, a one-level index structure is used for bin-by-bin searching. `binblocks' is a one-word bitvector recording whether groups of BINBLOCKWIDTH bins have any (possibly) non-empty bins, so they can be skipped over all at once during during traversals. The bits are NOT always cleared as soon as all bins in a block are empty, but instead only when all are noticed to be empty during traversal in malloc. */ #define BINBLOCKWIDTH 4 /* bins per block */ /* bin<->block macros */ #define idx2binblock(ix) ((unsigned)1 << ((ix) / BINBLOCKWIDTH)) #define mark_binblock(a, ii) (binblocks(a) |= idx2binblock(ii)) #define clear_binblock(a, ii) (binblocks(a) &= ~(idx2binblock(ii))) /* Static bookkeeping data */ /* Helper macro to initialize bins */ #define IAV(i) _bin_at(&main_arena, i), _bin_at(&main_arena, i) static arena main_arena = { { 0, 0, IAV(0), IAV(1), IAV(2), IAV(3), IAV(4), IAV(5), IAV(6), IAV(7), IAV(8), IAV(9), IAV(10), IAV(11), IAV(12), IAV(13), IAV(14), IAV(15), IAV(16), IAV(17), IAV(18), IAV(19), IAV(20), IAV(21), IAV(22), IAV(23), IAV(24), IAV(25), IAV(26), IAV(27), IAV(28), IAV(29), IAV(30), IAV(31), IAV(32), IAV(33), IAV(34), IAV(35), IAV(36), IAV(37), IAV(38), IAV(39), IAV(40), IAV(41), IAV(42), IAV(43), IAV(44), IAV(45), IAV(46), IAV(47), IAV(48), IAV(49), IAV(50), IAV(51), IAV(52), IAV(53), IAV(54), IAV(55), IAV(56), IAV(57), IAV(58), IAV(59), IAV(60), IAV(61), IAV(62), IAV(63), IAV(64), IAV(65), IAV(66), IAV(67), IAV(68), IAV(69), IAV(70), IAV(71), IAV(72), IAV(73), IAV(74), IAV(75), IAV(76), IAV(77), IAV(78), IAV(79), IAV(80), IAV(81), IAV(82), IAV(83), IAV(84), IAV(85), IAV(86), IAV(87), IAV(88), IAV(89), IAV(90), IAV(91), IAV(92), IAV(93), IAV(94), IAV(95), IAV(96), IAV(97), IAV(98), IAV(99), IAV(100), IAV(101), IAV(102), IAV(103), IAV(104), IAV(105), IAV(106), IAV(107), IAV(108), IAV(109), IAV(110), IAV(111), IAV(112), IAV(113), IAV(114), IAV(115), IAV(116), IAV(117), IAV(118), IAV(119), IAV(120), IAV(121), IAV(122), IAV(123), IAV(124), IAV(125), IAV(126), IAV(127) }, &main_arena, /* next */ 0, /* size */ #if THREAD_STATS 0, 0, 0, /* stat_lock_direct, stat_lock_loop, stat_lock_wait */ #endif MUTEX_INITIALIZER /* mutex */ }; #undef IAV /* Thread specific data */ static tsd_key_t arena_key; static mutex_t list_lock = MUTEX_INITIALIZER; #if THREAD_STATS static int stat_n_heaps; #define THREAD_STAT(x) x #else #define THREAD_STAT(x) do ; while(0) #endif /* variables holding tunable values */ static unsigned long trim_threshold = DEFAULT_TRIM_THRESHOLD; static unsigned long top_pad = DEFAULT_TOP_PAD; static unsigned int n_mmaps_max = DEFAULT_MMAP_MAX; static unsigned long mmap_threshold = DEFAULT_MMAP_THRESHOLD; static int check_action = DEFAULT_CHECK_ACTION; /* The first value returned from sbrk */ static char* sbrk_base = (char*)(-1); /* The maximum memory obtained from system via sbrk */ static unsigned long max_sbrked_mem; /* The maximum via either sbrk or mmap (too difficult to track with threads) */ #ifdef NO_THREADS static unsigned long max_total_mem; #endif /* The total memory obtained from system via sbrk */ #define sbrked_mem (main_arena.size) /* Tracking mmaps */ static unsigned int n_mmaps; static unsigned int max_n_mmaps; static unsigned long mmapped_mem; static unsigned long max_mmapped_mem; /* Mapped memory in non-main arenas (reliable only for NO_THREADS). */ static unsigned long arena_mem; #ifndef _LIBC #define weak_variable #else /* In GNU libc we want the hook variables to be weak definitions to avoid a problem with Emacs. */ #define weak_variable weak_function #endif /* Already initialized? */ int __malloc_initialized = -1; #ifndef NO_THREADS /* Magic value for the thread-specific arena pointer when malloc_atfork() is in use. */ #define ATFORK_ARENA_PTR ((Void_t*)-1) /* The following two functions are registered via thread_atfork() to make sure that the mutexes remain in a consistent state in the fork()ed version of a thread. Also adapt the malloc and free hooks temporarily, because the `atfork' handler mechanism may use malloc/free internally (e.g. in LinuxThreads). */ #if defined _LIBC || defined MALLOC_HOOKS static __malloc_ptr_t (*save_malloc_hook) __MALLOC_P ((size_t __size, const __malloc_ptr_t)); static void (*save_free_hook) __MALLOC_P ((__malloc_ptr_t __ptr, const __malloc_ptr_t)); static Void_t* save_arena; #endif static void ptmalloc_lock_all __MALLOC_P((void)) { arena *ar_ptr; (void)mutex_lock(&list_lock); for(ar_ptr = &main_arena;;) { (void)mutex_lock(&ar_ptr->mutex); ar_ptr = ar_ptr->next; if(ar_ptr == &main_arena) break; } #if defined _LIBC || defined MALLOC_HOOKS save_malloc_hook = __malloc_hook; save_free_hook = __free_hook; __malloc_hook = malloc_atfork; __free_hook = free_atfork; /* Only the current thread may perform malloc/free calls now. */ tsd_getspecific(arena_key, save_arena); tsd_setspecific(arena_key, ATFORK_ARENA_PTR); #endif } static void ptmalloc_unlock_all __MALLOC_P((void)) { arena *ar_ptr; #if defined _LIBC || defined MALLOC_HOOKS tsd_setspecific(arena_key, save_arena); __malloc_hook = save_malloc_hook; __free_hook = save_free_hook; #endif for(ar_ptr = &main_arena;;) { (void)mutex_unlock(&ar_ptr->mutex); ar_ptr = ar_ptr->next; if(ar_ptr == &main_arena) break; } (void)mutex_unlock(&list_lock); } static void ptmalloc_init_all __MALLOC_P((void)) { arena *ar_ptr; #if defined _LIBC || defined MALLOC_HOOKS tsd_setspecific(arena_key, save_arena); __malloc_hook = save_malloc_hook; __free_hook = save_free_hook; #endif for(ar_ptr = &main_arena;;) { (void)mutex_init(&ar_ptr->mutex); ar_ptr = ar_ptr->next; if(ar_ptr == &main_arena) break; } (void)mutex_init(&list_lock); } #endif /* !defined NO_THREADS */ /* Initialization routine. */ #if defined(_LIBC) #if 0 static void ptmalloc_init __MALLOC_P ((void)) __attribute__ ((constructor)); #endif #ifdef _LIBC #include <string.h> extern char **environ; static char * internal_function next_env_entry (char ***position) { char **current = *position; char *result = NULL; while (*current != NULL) { if (__builtin_expect ((*current)[0] == 'M', 0) && (*current)[1] == 'A' && (*current)[2] == 'L' && (*current)[3] == 'L' && (*current)[4] == 'O' && (*current)[5] == 'C' && (*current)[6] == '_') { result = &(*current)[7]; /* Save current position for next visit. */ *position = ++current; break; } ++current; } return result; } #endif static void ptmalloc_init __MALLOC_P((void)) #else void ptmalloc_init __MALLOC_P((void)) #endif { #if defined _LIBC || defined MALLOC_HOOKS # if __STD_C const char* s; # else char* s; # endif #endif int secure; if(__malloc_initialized >= 0) return; __malloc_initialized = 0; #ifdef _LIBC __libc_pagesize = __getpagesize(); #endif #ifndef NO_THREADS #if defined _LIBC || defined MALLOC_HOOKS /* With some threads implementations, creating thread-specific data or initializing a mutex may call malloc() itself. Provide a simple starter version (realloc() won't work). */ save_malloc_hook = __malloc_hook; save_free_hook = __free_hook; __malloc_hook = malloc_starter; __free_hook = free_starter; #endif #ifdef _LIBC /* Initialize the pthreads interface. */ if (__pthread_initialize != NULL) __pthread_initialize(); #endif #endif /* !defined NO_THREADS */ mutex_init(&main_arena.mutex); mutex_init(&list_lock); tsd_key_create(&arena_key, NULL); tsd_setspecific(arena_key, (Void_t *)&main_arena); thread_atfork(ptmalloc_lock_all, ptmalloc_unlock_all, ptmalloc_init_all); #if defined _LIBC || defined MALLOC_HOOKS #ifndef NO_THREADS __malloc_hook = save_malloc_hook; __free_hook = save_free_hook; #endif secure = __libc_enable_secure; #ifdef _LIBC s = NULL; if (environ != NULL) { char **runp = environ; char *envline; while (__builtin_expect ((envline = next_env_entry (&runp)) != NULL, 0)) { size_t len = strcspn (envline, "="); if (envline[len] != '=') /* This is a "MALLOC_" variable at the end of the string without a '=' character. Ignore it since otherwise we will access invalid memory below. */ continue; switch (len) { case 6: if (memcmp (envline, "CHECK_", 6) == 0) s = &envline[7]; break; case 8: if (! secure && memcmp (envline, "TOP_PAD_", 8) == 0) mALLOPt(M_TOP_PAD, atoi(&envline[9])); break; case 9: if (! secure && memcmp (envline, "MMAP_MAX_", 9) == 0) mALLOPt(M_MMAP_MAX, atoi(&envline[10])); break; case 15: if (! secure) { if (memcmp (envline, "TRIM_THRESHOLD_", 15) == 0) mALLOPt(M_TRIM_THRESHOLD, atoi(&envline[16])); else if (memcmp (envline, "MMAP_THRESHOLD_", 15) == 0) mALLOPt(M_MMAP_THRESHOLD, atoi(&envline[16])); } break; default: break; } } } #else if (! secure) { if((s = getenv("MALLOC_TRIM_THRESHOLD_"))) mALLOPt(M_TRIM_THRESHOLD, atoi(s)); if((s = getenv("MALLOC_TOP_PAD_"))) mALLOPt(M_TOP_PAD, atoi(s)); if((s = getenv("MALLOC_MMAP_THRESHOLD_"))) mALLOPt(M_MMAP_THRESHOLD, atoi(s)); if((s = getenv("MALLOC_MMAP_MAX_"))) mALLOPt(M_MMAP_MAX, atoi(s)); } s = getenv("MALLOC_CHECK_"); #endif if(s) { if(s[0]) mALLOPt(M_CHECK_ACTION, (int)(s[0] - '0')); __malloc_check_init(); } if(__malloc_initialize_hook != NULL) (*__malloc_initialize_hook)(); #endif __malloc_initialized = 1; } /* There are platforms (e.g. Hurd) with a link-time hook mechanism. */ #ifdef thread_atfork_static thread_atfork_static(ptmalloc_lock_all, ptmalloc_unlock_all, \ ptmalloc_init_all) #endif #if defined _LIBC || defined MALLOC_HOOKS /* Hooks for debugging versions. The initial hooks just call the initialization routine, then do the normal work. */ static Void_t* #if __STD_C malloc_hook_ini(size_t sz, const __malloc_ptr_t caller) #else malloc_hook_ini(sz, caller) size_t sz; const __malloc_ptr_t caller; #endif { __malloc_hook = NULL; ptmalloc_init(); return mALLOc(sz); } static Void_t* #if __STD_C realloc_hook_ini(Void_t* ptr, size_t sz, const __malloc_ptr_t caller) #else realloc_hook_ini(ptr, sz, caller) Void_t* ptr; size_t sz; const __malloc_ptr_t caller; #endif { __malloc_hook = NULL; __realloc_hook = NULL; ptmalloc_init(); return rEALLOc(ptr, sz); } static Void_t* #if __STD_C memalign_hook_ini(size_t alignment, size_t sz, const __malloc_ptr_t caller) #else memalign_hook_ini(alignment, sz, caller) size_t alignment; size_t sz; const __malloc_ptr_t caller; #endif { __memalign_hook = NULL; ptmalloc_init(); return mEMALIGn(alignment, sz); } void weak_variable (*__malloc_initialize_hook) __MALLOC_P ((void)) = NULL; void weak_variable (*__free_hook) __MALLOC_P ((__malloc_ptr_t __ptr, const __malloc_ptr_t)) = NULL; __malloc_ptr_t weak_variable (*__malloc_hook) __MALLOC_P ((size_t __size, const __malloc_ptr_t)) = malloc_hook_ini; __malloc_ptr_t weak_variable (*__realloc_hook) __MALLOC_P ((__malloc_ptr_t __ptr, size_t __size, const __malloc_ptr_t)) = realloc_hook_ini; __malloc_ptr_t weak_variable (*__memalign_hook) __MALLOC_P ((size_t __alignment, size_t __size, const __malloc_ptr_t)) = memalign_hook_ini; void weak_variable (*__after_morecore_hook) __MALLOC_P ((void)) = NULL; /* Whether we are using malloc checking. */ static int using_malloc_checking; /* A flag that is set by malloc_set_state, to signal that malloc checking must not be enabled on the request from the user (via the MALLOC_CHECK_ environment variable). It is reset by __malloc_check_init to tell malloc_set_state that the user has requested malloc checking. The purpose of this flag is to make sure that malloc checking is not enabled when the heap to be restored was constructed without malloc checking, and thus does not contain the required magic bytes. Otherwise the heap would be corrupted by calls to free and realloc. If it turns out that the heap was created with malloc checking and the user has requested it malloc_set_state just calls __malloc_check_init again to enable it. On the other hand, reusing such a heap without further malloc checking is safe. */ static int disallow_malloc_check; /* Activate a standard set of debugging hooks. */ void __malloc_check_init() { if (disallow_malloc_check) { disallow_malloc_check = 0; return; } using_malloc_checking = 1; __malloc_hook = malloc_check; __free_hook = free_check; __realloc_hook = realloc_check; __memalign_hook = memalign_check; if(check_action & 1) fprintf(stderr, "malloc: using debugging hooks\n"); } #endif /* Routines dealing with mmap(). */ #if HAVE_MMAP #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 #if defined __GNUC__ && __GNUC__ >= 2 /* This function is only called from one place, inline it. */ __inline__ #endif static mchunkptr internal_function #if __STD_C mmap_chunk(size_t size) #else mmap_chunk(size) size_t size; #endif { size_t page_mask = malloc_getpagesize - 1; mchunkptr p; /* For mmapped chunks, the overhead is one SIZE_SZ unit larger, because * there is no following chunk whose prev_size field could be used. */ size = (size + SIZE_SZ + page_mask) & ~page_mask; p = (mchunkptr)MMAP(0, size, PROT_READ|PROT_WRITE, MAP_PRIVATE); if(p == (mchunkptr) MAP_FAILED) return 0; n_mmaps++; if (n_mmaps > max_n_mmaps) max_n_mmaps = n_mmaps; /* We demand that eight bytes into a page must be 8-byte aligned. */ assert(aligned_OK(chunk2mem(p))); /* The offset to the start of the mmapped region is stored * in the prev_size field of the chunk; normally it is zero, * but that can be changed in memalign(). */ p->prev_size = 0; set_head(p, size|IS_MMAPPED); mmapped_mem += size; if ((unsigned long)mmapped_mem > (unsigned long)max_mmapped_mem) max_mmapped_mem = mmapped_mem; #ifdef NO_THREADS if ((unsigned long)(mmapped_mem + arena_mem + sbrked_mem) > max_total_mem) max_total_mem = mmapped_mem + arena_mem + sbrked_mem; #endif return p; } static void internal_function #if __STD_C munmap_chunk(mchunkptr p) #else munmap_chunk(p) mchunkptr p; #endif { INTERNAL_SIZE_T size = chunksize(p); int ret; assert (chunk_is_mmapped(p)); assert(! ((char*)p >= sbrk_base && (char*)p < sbrk_base + sbrked_mem)); assert((n_mmaps > 0)); assert(((p->prev_size + size) & (malloc_getpagesize-1)) == 0); n_mmaps--; mmapped_mem -= (size + p->prev_size); ret = munmap((char *)p - p->prev_size, size + p->prev_size); /* munmap returns non-zero on failure */ assert(ret == 0); } #if HAVE_MREMAP static mchunkptr internal_function #if __STD_C mremap_chunk(mchunkptr p, size_t new_size) #else mremap_chunk(p, new_size) mchunkptr p; size_t new_size; #endif { size_t page_mask = malloc_getpagesize - 1; INTERNAL_SIZE_T offset = p->prev_size; INTERNAL_SIZE_T size = chunksize(p); char *cp; assert (chunk_is_mmapped(p)); assert(! ((char*)p >= sbrk_base && (char*)p < sbrk_base + sbrked_mem)); assert((n_mmaps > 0)); assert(((size + offset) & (malloc_getpagesize-1)) == 0); /* Note the extra SIZE_SZ overhead as in mmap_chunk(). */ new_size = (new_size + offset + SIZE_SZ + page_mask) & ~page_mask; cp = (char *)mremap((char *)p - offset, size + offset, new_size, MREMAP_MAYMOVE); if (cp == MAP_FAILED) return 0; p = (mchunkptr)(cp + offset); assert(aligned_OK(chunk2mem(p))); assert((p->prev_size == offset)); set_head(p, (new_size - offset)|IS_MMAPPED); mmapped_mem -= size + offset; mmapped_mem += new_size; if ((unsigned long)mmapped_mem > (unsigned long)max_mmapped_mem) max_mmapped_mem = mmapped_mem; #ifdef NO_THREADS if ((unsigned long)(mmapped_mem + arena_mem + sbrked_mem) > max_total_mem) max_total_mem = mmapped_mem + arena_mem + sbrked_mem; #endif return p; } #endif /* HAVE_MREMAP */ #endif /* HAVE_MMAP */ /* Managing heaps and arenas (for concurrent threads) */ #if USE_ARENAS /* Create a new heap. size is automatically rounded up to a multiple of the page size. */ static heap_info * internal_function #if __STD_C new_heap(size_t size) #else new_heap(size) size_t size; #endif { size_t page_mask = malloc_getpagesize - 1; char *p1, *p2; unsigned long ul; heap_info *h; if(size+top_pad < HEAP_MIN_SIZE) size = HEAP_MIN_SIZE; else if(size+top_pad <= HEAP_MAX_SIZE) size += top_pad; else if(size > HEAP_MAX_SIZE) return 0; else size = HEAP_MAX_SIZE; size = (size + page_mask) & ~page_mask; /* A memory region aligned to a multiple of HEAP_MAX_SIZE is needed. No swap space needs to be reserved for the following large mapping (on Linux, this is the case for all non-writable mappings anyway). */ p1 = (char *)MMAP(0, HEAP_MAX_SIZE<<1, PROT_NONE, MAP_PRIVATE|MAP_NORESERVE); if(p1 != MAP_FAILED) { p2 = (char *)(((unsigned long)p1 + (HEAP_MAX_SIZE-1)) & ~(HEAP_MAX_SIZE-1)); ul = p2 - p1; if (ul) munmap(p1, ul); munmap(p2 + HEAP_MAX_SIZE, HEAP_MAX_SIZE - ul); } else { /* Try to take the chance that an allocation of only HEAP_MAX_SIZE is already aligned. */ p2 = (char *)MMAP(0, HEAP_MAX_SIZE, PROT_NONE, MAP_PRIVATE|MAP_NORESERVE); if(p2 == MAP_FAILED) return 0; if((unsigned long)p2 & (HEAP_MAX_SIZE-1)) { munmap(p2, HEAP_MAX_SIZE); return 0; } } if(MMAP(p2, size, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED) == (char *) MAP_FAILED) { munmap(p2, HEAP_MAX_SIZE); return 0; } h = (heap_info *)p2; h->size = size; THREAD_STAT(stat_n_heaps++); return h; } /* Grow or shrink a heap. size is automatically rounded up to a multiple of the page size if it is positive. */ static int #if __STD_C grow_heap(heap_info *h, long diff) #else grow_heap(h, diff) heap_info *h; long diff; #endif { size_t page_mask = malloc_getpagesize - 1; long new_size; if(diff >= 0) { diff = (diff + page_mask) & ~page_mask; new_size = (long)h->size + diff; if(new_size > HEAP_MAX_SIZE) return -1; if(MMAP((char *)h + h->size, diff, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED) == (char *) MAP_FAILED) return -2; } else { new_size = (long)h->size + diff; if(new_size < (long)sizeof(*h)) return -1; /* Try to re-map the extra heap space freshly to save memory, and make it inaccessible. */ if((char *)MMAP((char *)h + new_size, -diff, PROT_NONE, MAP_PRIVATE|MAP_FIXED) == (char *) MAP_FAILED) return -2; } h->size = new_size; return 0; } /* Delete a heap. */ #define delete_heap(heap) munmap((char*)(heap), HEAP_MAX_SIZE) /* arena_get() acquires an arena and locks the corresponding mutex. First, try the one last locked successfully by this thread. (This is the common case and handled with a macro for speed.) Then, loop once over the circularly linked list of arenas. If no arena is readily available, create a new one. In this latter case, `size' is just a hint as to how much memory will be required immediately in the new arena. */ #define arena_get(ptr, size) do { \ Void_t *vptr = NULL; \ ptr = (arena *)tsd_getspecific(arena_key, vptr); \ if(ptr && !mutex_trylock(&ptr->mutex)) { \ THREAD_STAT(++(ptr->stat_lock_direct)); \ } else \ ptr = arena_get2(ptr, (size)); \ } while(0) static arena * internal_function #if __STD_C arena_get2(arena *a_tsd, size_t size) #else arena_get2(a_tsd, size) arena *a_tsd; size_t size; #endif { arena *a; heap_info *h; char *ptr; int i; unsigned long misalign; if(!a_tsd) a = a_tsd = &main_arena; else { a = a_tsd->next; if(!a) { /* This can only happen while initializing the new arena. */ (void)mutex_lock(&main_arena.mutex); THREAD_STAT(++(main_arena.stat_lock_wait)); return &main_arena; } } /* Check the global, circularly linked list for available arenas. */ repeat: do { if(!mutex_trylock(&a->mutex)) { THREAD_STAT(++(a->stat_lock_loop)); tsd_setspecific(arena_key, (Void_t *)a); return a; } a = a->next; } while(a != a_tsd); /* If not even the list_lock can be obtained, try again. This can happen during `atfork', or for example on systems where thread creation makes it temporarily impossible to obtain _any_ locks. */ if(mutex_trylock(&list_lock)) { a = a_tsd; goto repeat; } (void)mutex_unlock(&list_lock); /* Nothing immediately available, so generate a new arena. */ h = new_heap(size + (sizeof(*h) + sizeof(*a) + MALLOC_ALIGNMENT)); if(!h) { /* Maybe size is too large to fit in a single heap. So, just try to create a minimally-sized arena and let chunk_alloc() attempt to deal with the large request via mmap_chunk(). */ h = new_heap(sizeof(*h) + sizeof(*a) + MALLOC_ALIGNMENT); if(!h) return 0; } a = h->ar_ptr = (arena *)(h+1); for(i=0; i<NAV; i++) init_bin(a, i); a->next = NULL; a->size = h->size; arena_mem += h->size; #ifdef NO_THREADS if((unsigned long)(mmapped_mem + arena_mem + sbrked_mem) > max_total_mem) max_total_mem = mmapped_mem + arena_mem + sbrked_mem; #endif tsd_setspecific(arena_key, (Void_t *)a); mutex_init(&a->mutex); i = mutex_lock(&a->mutex); /* remember result */ /* Set up the top chunk, with proper alignment. */ ptr = (char *)(a + 1); misalign = (unsigned long)chunk2mem(ptr) & MALLOC_ALIGN_MASK; if (misalign > 0) ptr += MALLOC_ALIGNMENT - misalign; top(a) = (mchunkptr)ptr; set_head(top(a), (((char*)h + h->size) - ptr) | PREV_INUSE); /* Add the new arena to the list. */ (void)mutex_lock(&list_lock); a->next = main_arena.next; main_arena.next = a; (void)mutex_unlock(&list_lock); if(i) /* locking failed; keep arena for further attempts later */ return 0; THREAD_STAT(++(a->stat_lock_loop)); return a; } /* find the heap and corresponding arena for a given ptr */ #define heap_for_ptr(ptr) \ ((heap_info *)((unsigned long)(ptr) & ~(HEAP_MAX_SIZE-1))) #define arena_for_ptr(ptr) \ (((mchunkptr)(ptr) < top(&main_arena) && (char *)(ptr) >= sbrk_base) ? \ &main_arena : heap_for_ptr(ptr)->ar_ptr) #else /* !USE_ARENAS */ /* There is only one arena, main_arena. */ #define arena_get(ptr, sz) (ptr = &main_arena) #define arena_for_ptr(ptr) (&main_arena) #endif /* USE_ARENAS */ /* Debugging support */ #if MALLOC_DEBUG /* These routines make a number of assertions about the states of data structures that should be true at all times. If any are not true, it's very likely that a user program has somehow trashed memory. (It's also possible that there is a coding error in malloc. In which case, please report it!) */ #if __STD_C static void do_check_chunk(arena *ar_ptr, mchunkptr p) #else static void do_check_chunk(ar_ptr, p) arena *ar_ptr; mchunkptr p; #endif { INTERNAL_SIZE_T sz = p->size & ~PREV_INUSE; /* No checkable chunk is mmapped */ assert(!chunk_is_mmapped(p)); #if USE_ARENAS if(ar_ptr != &main_arena) { heap_info *heap = heap_for_ptr(p); assert(heap->ar_ptr == ar_ptr); if(p != top(ar_ptr)) assert((char *)p + sz <= (char *)heap + heap->size); else assert((char *)p + sz == (char *)heap + heap->size); return; } #endif /* Check for legal address ... */ assert((char*)p >= sbrk_base); if (p != top(ar_ptr)) assert((char*)p + sz <= (char*)top(ar_ptr)); else assert((char*)p + sz <= sbrk_base + sbrked_mem); } #if __STD_C static void do_check_free_chunk(arena *ar_ptr, mchunkptr p) #else static void do_check_free_chunk(ar_ptr, p) arena *ar_ptr; mchunkptr p; #endif { INTERNAL_SIZE_T sz = p->size & ~PREV_INUSE; mchunkptr next = chunk_at_offset(p, sz); do_check_chunk(ar_ptr, p); /* Check whether it claims to be free ... */ assert(!inuse(p)); /* Must have OK size and fields */ assert((long)sz >= (long)MINSIZE); assert((sz & MALLOC_ALIGN_MASK) == 0); assert(aligned_OK(chunk2mem(p))); /* ... matching footer field */ assert(next->prev_size == sz); /* ... and is fully consolidated */ assert(prev_inuse(p)); assert (next == top(ar_ptr) || inuse(next)); /* ... and has minimally sane links */ assert(p->fd->bk == p); assert(p->bk->fd == p); } #if __STD_C static void do_check_inuse_chunk(arena *ar_ptr, mchunkptr p) #else static void do_check_inuse_chunk(ar_ptr, p) arena *ar_ptr; mchunkptr p; #endif { mchunkptr next = next_chunk(p); do_check_chunk(ar_ptr, p); /* Check whether it claims to be in use ... */ assert(inuse(p)); /* ... whether its size is OK (it might be a fencepost) ... */ assert(chunksize(p) >= MINSIZE || next->size == (0|PREV_INUSE)); /* ... and is surrounded by OK chunks. Since more things can be checked with free chunks than inuse ones, if an inuse chunk borders them and debug is on, it's worth doing them. */ if (!prev_inuse(p)) { mchunkptr prv = prev_chunk(p); assert(next_chunk(prv) == p); do_check_free_chunk(ar_ptr, prv); } if (next == top(ar_ptr)) { assert(prev_inuse(next)); assert(chunksize(next) >= MINSIZE); } else if (!inuse(next)) do_check_free_chunk(ar_ptr, next); } #if __STD_C static void do_check_malloced_chunk(arena *ar_ptr, mchunkptr p, INTERNAL_SIZE_T s) #else static void do_check_malloced_chunk(ar_ptr, p, s) arena *ar_ptr; mchunkptr p; INTERNAL_SIZE_T s; #endif { INTERNAL_SIZE_T sz = p->size & ~PREV_INUSE; long room = sz - s; do_check_inuse_chunk(ar_ptr, p); /* Legal size ... */ assert((long)sz >= (long)MINSIZE); assert((sz & MALLOC_ALIGN_MASK) == 0); assert(room >= 0); assert(room < (long)MINSIZE); /* ... and alignment */ assert(aligned_OK(chunk2mem(p))); /* ... and was allocated at front of an available chunk */ assert(prev_inuse(p)); } #define check_free_chunk(A,P) do_check_free_chunk(A,P) #define check_inuse_chunk(A,P) do_check_inuse_chunk(A,P) #define check_chunk(A,P) do_check_chunk(A,P) #define check_malloced_chunk(A,P,N) do_check_malloced_chunk(A,P,N) #else #define check_free_chunk(A,P) #define check_inuse_chunk(A,P) #define check_chunk(A,P) #define check_malloced_chunk(A,P,N) #endif /* Macro-based internal utilities */ /* Linking chunks in bin lists. Call these only with variables, not arbitrary expressions, as arguments. */ /* Place chunk p of size s in its bin, in size order, putting it ahead of others of same size. */ #define frontlink(A, P, S, IDX, BK, FD) \ { \ if (S < MAX_SMALLBIN_SIZE) \ { \ IDX = smallbin_index(S); \ mark_binblock(A, IDX); \ BK = bin_at(A, IDX); \ FD = BK->fd; \ P->bk = BK; \ P->fd = FD; \ FD->bk = BK->fd = P; \ } \ else \ { \ IDX = bin_index(S); \ BK = bin_at(A, IDX); \ FD = BK->fd; \ if (FD == BK) mark_binblock(A, IDX); \ else \ { \ while (FD != BK && S < chunksize(FD)) FD = FD->fd; \ BK = FD->bk; \ } \ P->bk = BK; \ P->fd = FD; \ FD->bk = BK->fd = P; \ } \ } /* take a chunk off a list */ #define unlink(P, BK, FD) \ { \ BK = P->bk; \ FD = P->fd; \ FD->bk = BK; \ BK->fd = FD; \ } \ /* Place p as the last remainder */ #define link_last_remainder(A, P) \ { \ last_remainder(A)->fd = last_remainder(A)->bk = P; \ P->fd = P->bk = last_remainder(A); \ } /* Clear the last_remainder bin */ #define clear_last_remainder(A) \ (last_remainder(A)->fd = last_remainder(A)->bk = last_remainder(A)) /* Extend the top-most chunk by obtaining memory from system. Main interface to sbrk (but see also malloc_trim). */ #if defined __GNUC__ && __GNUC__ >= 2 /* This function is called only from one place, inline it. */ __inline__ #endif static void internal_function #if __STD_C malloc_extend_top(arena *ar_ptr, INTERNAL_SIZE_T nb) #else malloc_extend_top(ar_ptr, nb) arena *ar_ptr; INTERNAL_SIZE_T nb; #endif { unsigned long pagesz = malloc_getpagesize; mchunkptr old_top = top(ar_ptr); /* Record state of old top */ INTERNAL_SIZE_T old_top_size = chunksize(old_top); INTERNAL_SIZE_T top_size; /* new size of top chunk */ #if USE_ARENAS if(ar_ptr == &main_arena) { #endif char* brk; /* return value from sbrk */ INTERNAL_SIZE_T front_misalign; /* unusable bytes at front of sbrked space */ INTERNAL_SIZE_T correction; /* bytes for 2nd sbrk call */ char* new_brk; /* return of 2nd sbrk call */ char* old_end = (char*)(chunk_at_offset(old_top, old_top_size)); /* Pad request with top_pad plus minimal overhead */ INTERNAL_SIZE_T sbrk_size = nb + top_pad + MINSIZE; /* If not the first time through, round to preserve page boundary */ /* Otherwise, we need to correct to a page size below anyway. */ /* (We also correct below if an intervening foreign sbrk call.) */ if (sbrk_base != (char*)(-1)) sbrk_size = (sbrk_size + (pagesz - 1)) & ~(pagesz - 1); brk = (char*)(MORECORE (sbrk_size)); /* Fail if sbrk failed or if a foreign sbrk call killed our space */ if (brk == (char*)(MORECORE_FAILURE) || (brk < old_end && old_top != initial_top(&main_arena))) return; #if defined _LIBC || defined MALLOC_HOOKS /* Call the `morecore' hook if necessary. */ if (__after_morecore_hook) (*__after_morecore_hook) (); #endif sbrked_mem += sbrk_size; if (brk == old_end) { /* can just add bytes to current top */ top_size = sbrk_size + old_top_size; set_head(old_top, top_size | PREV_INUSE); old_top = 0; /* don't free below */ } else { if (sbrk_base == (char*)(-1)) /* First time through. Record base */ sbrk_base = brk; else /* Someone else called sbrk(). Count those bytes as sbrked_mem. */ sbrked_mem += brk - (char*)old_end; /* Guarantee alignment of first new chunk made from this space */ front_misalign = (unsigned long)chunk2mem(brk) & MALLOC_ALIGN_MASK; if (front_misalign > 0) { correction = (MALLOC_ALIGNMENT) - front_misalign; brk += correction; } else correction = 0; /* Guarantee the next brk will be at a page boundary */ correction += pagesz - ((unsigned long)(brk + sbrk_size) & (pagesz - 1)); /* Allocate correction */ new_brk = (char*)(MORECORE (correction)); if (new_brk == (char*)(MORECORE_FAILURE)) return; #if defined _LIBC || defined MALLOC_HOOKS /* Call the `morecore' hook if necessary. */ if (__after_morecore_hook) (*__after_morecore_hook) (); #endif sbrked_mem += correction; top(&main_arena) = chunk_at_offset(brk, 0); top_size = new_brk - brk + correction; set_head(top(&main_arena), top_size | PREV_INUSE); if (old_top == initial_top(&main_arena)) old_top = 0; /* don't free below */ } if ((unsigned long)sbrked_mem > (unsigned long)max_sbrked_mem) max_sbrked_mem = sbrked_mem; #ifdef NO_THREADS if ((unsigned long)(mmapped_mem + arena_mem + sbrked_mem) > max_total_mem) max_total_mem = mmapped_mem + arena_mem + sbrked_mem; #endif #if USE_ARENAS } else { /* ar_ptr != &main_arena */ heap_info *old_heap, *heap; size_t old_heap_size; if(old_top_size < MINSIZE) /* this should never happen */ return; /* First try to extend the current heap. */ if(MINSIZE + nb <= old_top_size) return; old_heap = heap_for_ptr(old_top); old_heap_size = old_heap->size; if(grow_heap(old_heap, MINSIZE + nb - old_top_size) == 0) { ar_ptr->size += old_heap->size - old_heap_size; arena_mem += old_heap->size - old_heap_size; #ifdef NO_THREADS if(mmapped_mem + arena_mem + sbrked_mem > max_total_mem) max_total_mem = mmapped_mem + arena_mem + sbrked_mem; #endif top_size = ((char *)old_heap + old_heap->size) - (char *)old_top; set_head(old_top, top_size | PREV_INUSE); return; } /* A new heap must be created. */ heap = new_heap(nb + (MINSIZE + sizeof(*heap))); if(!heap) return; heap->ar_ptr = ar_ptr; heap->prev = old_heap; ar_ptr->size += heap->size; arena_mem += heap->size; #ifdef NO_THREADS if((unsigned long)(mmapped_mem + arena_mem + sbrked_mem) > max_total_mem) max_total_mem = mmapped_mem + arena_mem + sbrked_mem; #endif /* Set up the new top, so we can safely use chunk_free() below. */ top(ar_ptr) = chunk_at_offset(heap, sizeof(*heap)); top_size = heap->size - sizeof(*heap); set_head(top(ar_ptr), top_size | PREV_INUSE); } #endif /* USE_ARENAS */ /* We always land on a page boundary */ assert(((unsigned long)((char*)top(ar_ptr) + top_size) & (pagesz-1)) == 0); /* Setup fencepost and free the old top chunk. */ if(old_top) { /* The fencepost takes at least MINSIZE bytes, because it might become the top chunk again later. Note that a footer is set up, too, although the chunk is marked in use. */ old_top_size -= MINSIZE; set_head(chunk_at_offset(old_top, old_top_size + 2*SIZE_SZ), 0|PREV_INUSE); if(old_top_size >= MINSIZE) { set_head(chunk_at_offset(old_top, old_top_size), (2*SIZE_SZ)|PREV_INUSE); set_foot(chunk_at_offset(old_top, old_top_size), (2*SIZE_SZ)); set_head_size(old_top, old_top_size); chunk_free(ar_ptr, old_top); } else { set_head(old_top, (old_top_size + 2*SIZE_SZ)|PREV_INUSE); set_foot(old_top, (old_top_size + 2*SIZE_SZ)); } } } /* Main public routines */ /* Malloc Algorithm: The requested size is first converted into a usable form, `nb'. This currently means to add 4 bytes overhead plus possibly more to obtain 8-byte alignment and/or to obtain a size of at least MINSIZE (currently 16, 24, or 32 bytes), the smallest allocatable size. (All fits are considered `exact' if they are within MINSIZE bytes.) From there, the first successful of the following steps is taken: 1. The bin corresponding to the request size is scanned, and if a chunk of exactly the right size is found, it is taken. 2. The most recently remaindered chunk is used if it is big enough. This is a form of (roving) first fit, used only in the absence of exact fits. Runs of consecutive requests use the remainder of the chunk used for the previous such request whenever possible. This limited use of a first-fit style allocation strategy tends to give contiguous chunks coextensive lifetimes, which improves locality and can reduce fragmentation in the long run. 3. Other bins are scanned in increasing size order, using a chunk big enough to fulfill the request, and splitting off any remainder. This search is strictly by best-fit; i.e., the smallest (with ties going to approximately the least recently used) chunk that fits is selected. 4. If large enough, the chunk bordering the end of memory (`top') is split off. (This use of `top' is in accord with the best-fit search rule. In effect, `top' is treated as larger (and thus less well fitting) than any other available chunk since it can be extended to be as large as necessary (up to system limitations). 5. If the request size meets the mmap threshold and the system supports mmap, and there are few enough currently allocated mmapped regions, and a call to mmap succeeds, the request is allocated via direct memory mapping. 6. Otherwise, the top of memory is extended by obtaining more space from the system (normally using sbrk, but definable to anything else via the MORECORE macro). Memory is gathered from the system (in system page-sized units) in a way that allows chunks obtained across different sbrk calls to be consolidated, but does not require contiguous memory. Thus, it should be safe to intersperse mallocs with other sbrk calls. All allocations are made from the `lowest' part of any found chunk. (The implementation invariant is that prev_inuse is always true of any allocated chunk; i.e., that each allocated chunk borders either a previously allocated and still in-use chunk, or the base of its memory arena.) */ #if __STD_C Void_t* mALLOc(size_t bytes) #else Void_t* mALLOc(bytes) size_t bytes; #endif { arena *ar_ptr; INTERNAL_SIZE_T nb; /* padded request size */ mchunkptr victim; #if defined _LIBC || defined MALLOC_HOOKS __malloc_ptr_t (*hook) __MALLOC_PMT ((size_t, __const __malloc_ptr_t)) = __malloc_hook; if (hook != NULL) { Void_t* result; #if defined __GNUC__ && __GNUC__ >= 2 result = (*hook)(bytes, RETURN_ADDRESS (0)); #else result = (*hook)(bytes, NULL); #endif return result; } #endif if(request2size(bytes, nb)) return 0; arena_get(ar_ptr, nb); if(!ar_ptr) return 0; victim = chunk_alloc(ar_ptr, nb); if(!victim) { /* Maybe the failure is due to running out of mmapped areas. */ if(ar_ptr != &main_arena) { (void)mutex_unlock(&ar_ptr->mutex); (void)mutex_lock(&main_arena.mutex); victim = chunk_alloc(&main_arena, nb); (void)mutex_unlock(&main_arena.mutex); } else { #if USE_ARENAS /* ... or sbrk() has failed and there is still a chance to mmap() */ ar_ptr = arena_get2(ar_ptr->next ? ar_ptr : 0, nb); (void)mutex_unlock(&main_arena.mutex); if(ar_ptr) { victim = chunk_alloc(ar_ptr, nb); (void)mutex_unlock(&ar_ptr->mutex); } #endif } if(!victim) return 0; } else (void)mutex_unlock(&ar_ptr->mutex); return BOUNDED_N(chunk2mem(victim), bytes); } static mchunkptr internal_function #if __STD_C chunk_alloc(arena *ar_ptr, INTERNAL_SIZE_T nb) #else chunk_alloc(ar_ptr, nb) arena *ar_ptr; INTERNAL_SIZE_T nb; #endif { mchunkptr victim; /* inspected/selected chunk */ INTERNAL_SIZE_T victim_size; /* its size */ int idx; /* index for bin traversal */ mbinptr bin; /* associated bin */ mchunkptr remainder; /* remainder from a split */ long remainder_size; /* its size */ int remainder_index; /* its bin index */ unsigned long block; /* block traverser bit */ int startidx; /* first bin of a traversed block */ mchunkptr fwd; /* misc temp for linking */ mchunkptr bck; /* misc temp for linking */ mbinptr q; /* misc temp */ /* Check for exact match in a bin */ if (is_small_request(nb)) /* Faster version for small requests */ { idx = smallbin_index(nb); /* No traversal or size check necessary for small bins. */ q = _bin_at(ar_ptr, idx); victim = last(q); /* Also scan the next one, since it would have a remainder < MINSIZE */ if (victim == q) { q = next_bin(q); victim = last(q); } if (victim != q) { victim_size = chunksize(victim); unlink(victim, bck, fwd); set_inuse_bit_at_offset(victim, victim_size); check_malloced_chunk(ar_ptr, victim, nb); return victim; } idx += 2; /* Set for bin scan below. We've already scanned 2 bins. */ } else { idx = bin_index(nb); bin = bin_at(ar_ptr, idx); for (victim = last(bin); victim != bin; victim = victim->bk) { victim_size = chunksize(victim); remainder_size = victim_size - nb; if (remainder_size >= (long)MINSIZE) /* too big */ { --idx; /* adjust to rescan below after checking last remainder */ break; } else if (remainder_size >= 0) /* exact fit */ { unlink(victim, bck, fwd); set_inuse_bit_at_offset(victim, victim_size); check_malloced_chunk(ar_ptr, victim, nb); return victim; } } ++idx; } /* Try to use the last split-off remainder */ if ( (victim = last_remainder(ar_ptr)->fd) != last_remainder(ar_ptr)) { victim_size = chunksize(victim); remainder_size = victim_size - nb; if (remainder_size >= (long)MINSIZE) /* re-split */ { remainder = chunk_at_offset(victim, nb); set_head(victim, nb | PREV_INUSE); link_last_remainder(ar_ptr, remainder); set_head(remainder, remainder_size | PREV_INUSE); set_foot(remainder, remainder_size); check_malloced_chunk(ar_ptr, victim, nb); return victim; } clear_last_remainder(ar_ptr); if (remainder_size >= 0) /* exhaust */ { set_inuse_bit_at_offset(victim, victim_size); check_malloced_chunk(ar_ptr, victim, nb); return victim; } /* Else place in bin */ frontlink(ar_ptr, victim, victim_size, remainder_index, bck, fwd); } /* If there are any possibly nonempty big-enough blocks, search for best fitting chunk by scanning bins in blockwidth units. */ if ( (block = idx2binblock(idx)) <= binblocks(ar_ptr)) { /* Get to the first marked block */ if ( (block & binblocks(ar_ptr)) == 0) { /* force to an even block boundary */ idx = (idx & ~(BINBLOCKWIDTH - 1)) + BINBLOCKWIDTH; block <<= 1; while ((block & binblocks(ar_ptr)) == 0) { idx += BINBLOCKWIDTH; block <<= 1; } } /* For each possibly nonempty block ... */ for (;;) { startidx = idx; /* (track incomplete blocks) */ q = bin = _bin_at(ar_ptr, idx); /* For each bin in this block ... */ do { /* Find and use first big enough chunk ... */ for (victim = last(bin); victim != bin; victim = victim->bk) { victim_size = chunksize(victim); remainder_size = victim_size - nb; if (remainder_size >= (long)MINSIZE) /* split */ { remainder = chunk_at_offset(victim, nb); set_head(victim, nb | PREV_INUSE); unlink(victim, bck, fwd); link_last_remainder(ar_ptr, remainder); set_head(remainder, remainder_size | PREV_INUSE); set_foot(remainder, remainder_size); check_malloced_chunk(ar_ptr, victim, nb); return victim; } else if (remainder_size >= 0) /* take */ { set_inuse_bit_at_offset(victim, victim_size); unlink(victim, bck, fwd); check_malloced_chunk(ar_ptr, victim, nb); return victim; } } bin = next_bin(bin); } while ((++idx & (BINBLOCKWIDTH - 1)) != 0); /* Clear out the block bit. */ do /* Possibly backtrack to try to clear a partial block */ { if ((startidx & (BINBLOCKWIDTH - 1)) == 0) { binblocks(ar_ptr) &= ~block; break; } --startidx; q = prev_bin(q); } while (first(q) == q); /* Get to the next possibly nonempty block */ if ( (block <<= 1) <= binblocks(ar_ptr) && (block != 0) ) { while ((block & binblocks(ar_ptr)) == 0) { idx += BINBLOCKWIDTH; block <<= 1; } } else break; } } /* Try to use top chunk */ /* Require that there be a remainder, ensuring top always exists */ if ( (remainder_size = chunksize(top(ar_ptr)) - nb) < (long)MINSIZE) { #if HAVE_MMAP /* If the request is big and there are not yet too many regions, and we would otherwise need to extend, try to use mmap instead. */ if ((unsigned long)nb >= (unsigned long)mmap_threshold && n_mmaps < n_mmaps_max && (victim = mmap_chunk(nb)) != 0) return victim; #endif /* Try to extend */ malloc_extend_top(ar_ptr, nb); if ((remainder_size = chunksize(top(ar_ptr)) - nb) < (long)MINSIZE) { #if HAVE_MMAP /* A last attempt: when we are out of address space in a non-main arena, try mmap anyway, as long as it is allowed at all. */ if (ar_ptr != &main_arena && n_mmaps_max > 0 && (victim = mmap_chunk(nb)) != 0) return victim; #endif return 0; /* propagate failure */ } } victim = top(ar_ptr); set_head(victim, nb | PREV_INUSE); top(ar_ptr) = chunk_at_offset(victim, nb); set_head(top(ar_ptr), remainder_size | PREV_INUSE); check_malloced_chunk(ar_ptr, victim, nb); return victim; } /* free() algorithm : cases: 1. free(0) has no effect. 2. If the chunk was allocated via mmap, it is released via munmap(). 3. If a returned chunk borders the current high end of memory, it is consolidated into the top, and if the total unused topmost memory exceeds the trim threshold, malloc_trim is called. 4. Other chunks are consolidated as they arrive, and placed in corresponding bins. (This includes the case of consolidating with the current `last_remainder'). */ #if __STD_C void fREe(Void_t* mem) #else void fREe(mem) Void_t* mem; #endif { arena *ar_ptr; mchunkptr p; /* chunk corresponding to mem */ #if defined _LIBC || defined MALLOC_HOOKS void (*hook) __MALLOC_PMT ((__malloc_ptr_t, __const __malloc_ptr_t)) = __free_hook; if (hook != NULL) { #if defined __GNUC__ && __GNUC__ >= 2 (*hook)(mem, RETURN_ADDRESS (0)); #else (*hook)(mem, NULL); #endif return; } #endif if (mem == 0) /* free(0) has no effect */ return; p = mem2chunk(mem); #if HAVE_MMAP if (chunk_is_mmapped(p)) /* release mmapped memory. */ { munmap_chunk(p); return; } #endif ar_ptr = arena_for_ptr(p); #if THREAD_STATS if(!mutex_trylock(&ar_ptr->mutex)) ++(ar_ptr->stat_lock_direct); else { (void)mutex_lock(&ar_ptr->mutex); ++(ar_ptr->stat_lock_wait); } #else (void)mutex_lock(&ar_ptr->mutex); #endif chunk_free(ar_ptr, p); (void)mutex_unlock(&ar_ptr->mutex); } static void internal_function #if __STD_C chunk_free(arena *ar_ptr, mchunkptr p) #else chunk_free(ar_ptr, p) arena *ar_ptr; mchunkptr p; #endif { INTERNAL_SIZE_T hd = p->size; /* its head field */ INTERNAL_SIZE_T sz; /* its size */ int idx; /* its bin index */ mchunkptr next; /* next contiguous chunk */ INTERNAL_SIZE_T nextsz; /* its size */ INTERNAL_SIZE_T prevsz; /* size of previous contiguous chunk */ mchunkptr bck; /* misc temp for linking */ mchunkptr fwd; /* misc temp for linking */ int islr; /* track whether merging with last_remainder */ check_inuse_chunk(ar_ptr, p); sz = hd & ~PREV_INUSE; next = chunk_at_offset(p, sz); nextsz = chunksize(next); if (next == top(ar_ptr)) /* merge with top */ { sz += nextsz; if (!(hd & PREV_INUSE)) /* consolidate backward */ { prevsz = p->prev_size; p = chunk_at_offset(p, -(long)prevsz); sz += prevsz; unlink(p, bck, fwd); } set_head(p, sz | PREV_INUSE); top(ar_ptr) = p; #if USE_ARENAS if(ar_ptr == &main_arena) { #endif if ((unsigned long)(sz) >= (unsigned long)trim_threshold) main_trim(top_pad); #if USE_ARENAS } else { heap_info *heap = heap_for_ptr(p); assert(heap->ar_ptr == ar_ptr); /* Try to get rid of completely empty heaps, if possible. */ if((unsigned long)(sz) >= (unsigned long)trim_threshold || p == chunk_at_offset(heap, sizeof(*heap))) heap_trim(heap, top_pad); } #endif return; } islr = 0; if (!(hd & PREV_INUSE)) /* consolidate backward */ { prevsz = p->prev_size; p = chunk_at_offset(p, -(long)prevsz); sz += prevsz; if (p->fd == last_remainder(ar_ptr)) /* keep as last_remainder */ islr = 1; else unlink(p, bck, fwd); } if (!(inuse_bit_at_offset(next, nextsz))) /* consolidate forward */ { sz += nextsz; if (!islr && next->fd == last_remainder(ar_ptr)) /* re-insert last_remainder */ { islr = 1; link_last_remainder(ar_ptr, p); } else unlink(next, bck, fwd); next = chunk_at_offset(p, sz); } else set_head(next, nextsz); /* clear inuse bit */ set_head(p, sz | PREV_INUSE); next->prev_size = sz; if (!islr) frontlink(ar_ptr, p, sz, idx, bck, fwd); #if USE_ARENAS /* Check whether the heap containing top can go away now. */ if(next->size < MINSIZE && (unsigned long)sz > trim_threshold && ar_ptr != &main_arena) { /* fencepost */ heap_info *heap = heap_for_ptr(top(ar_ptr)); if(top(ar_ptr) == chunk_at_offset(heap, sizeof(*heap)) && heap->prev == heap_for_ptr(p)) heap_trim(heap, top_pad); } #endif } /* Realloc algorithm: Chunks that were obtained via mmap cannot be extended or shrunk unless HAVE_MREMAP is defined, in which case mremap is used. Otherwise, if their reallocation is for additional space, they are copied. If for less, they are just left alone. Otherwise, if the reallocation is for additional space, and the chunk can be extended, it is, else a malloc-copy-free sequence is taken. There are several different ways that a chunk could be extended. All are tried: * Extending forward into following adjacent free chunk. * Shifting backwards, joining preceding adjacent space * Both shifting backwards and extending forward. * Extending into newly sbrked space Unless the #define REALLOC_ZERO_BYTES_FREES is set, realloc with a size argument of zero (re)allocates a minimum-sized chunk. If the reallocation is for less space, and the new request is for a `small' (<512 bytes) size, then the newly unused space is lopped off and freed. The old unix realloc convention of allowing the last-free'd chunk to be used as an argument to realloc is no longer supported. I don't know of any programs still relying on this feature, and allowing it would also allow too many other incorrect usages of realloc to be sensible. */ #if __STD_C Void_t* rEALLOc(Void_t* oldmem, size_t bytes) #else Void_t* rEALLOc(oldmem, bytes) Void_t* oldmem; size_t bytes; #endif { arena *ar_ptr; INTERNAL_SIZE_T nb; /* padded request size */ mchunkptr oldp; /* chunk corresponding to oldmem */ INTERNAL_SIZE_T oldsize; /* its size */ mchunkptr newp; /* chunk to return */ #if defined _LIBC || defined MALLOC_HOOKS __malloc_ptr_t (*hook) __MALLOC_PMT ((__malloc_ptr_t, size_t, __const __malloc_ptr_t)) = __realloc_hook; if (hook != NULL) { Void_t* result; #if defined __GNUC__ && __GNUC__ >= 2 result = (*hook)(oldmem, bytes, RETURN_ADDRESS (0)); #else result = (*hook)(oldmem, bytes, NULL); #endif return result; } #endif #ifdef REALLOC_ZERO_BYTES_FREES if (bytes == 0 && oldmem != NULL) { fREe(oldmem); return 0; } #endif /* realloc of null is supposed to be same as malloc */ if (oldmem == 0) return mALLOc(bytes); oldp = mem2chunk(oldmem); oldsize = chunksize(oldp); if(request2size(bytes, nb)) return 0; #if HAVE_MMAP if (chunk_is_mmapped(oldp)) { Void_t* newmem; #if HAVE_MREMAP newp = mremap_chunk(oldp, nb); if(newp) return BOUNDED_N(chunk2mem(newp), bytes); #endif /* Note the extra SIZE_SZ overhead. */ if(oldsize - SIZE_SZ >= nb) return oldmem; /* do nothing */ /* Must alloc, copy, free. */ newmem = mALLOc(bytes); if (newmem == 0) return 0; /* propagate failure */ MALLOC_COPY(newmem, oldmem, oldsize - 2*SIZE_SZ, 0); munmap_chunk(oldp); return newmem; } #endif ar_ptr = arena_for_ptr(oldp); #if THREAD_STATS if(!mutex_trylock(&ar_ptr->mutex)) ++(ar_ptr->stat_lock_direct); else { (void)mutex_lock(&ar_ptr->mutex); ++(ar_ptr->stat_lock_wait); } #else (void)mutex_lock(&ar_ptr->mutex); #endif #ifndef NO_THREADS /* As in malloc(), remember this arena for the next allocation. */ tsd_setspecific(arena_key, (Void_t *)ar_ptr); #endif newp = chunk_realloc(ar_ptr, oldp, oldsize, nb); (void)mutex_unlock(&ar_ptr->mutex); return newp ? BOUNDED_N(chunk2mem(newp), bytes) : NULL; } static mchunkptr internal_function #if __STD_C chunk_realloc(arena* ar_ptr, mchunkptr oldp, INTERNAL_SIZE_T oldsize, INTERNAL_SIZE_T nb) #else chunk_realloc(ar_ptr, oldp, oldsize, nb) arena* ar_ptr; mchunkptr oldp; INTERNAL_SIZE_T oldsize, nb; #endif { mchunkptr newp = oldp; /* chunk to return */ INTERNAL_SIZE_T newsize = oldsize; /* its size */ mchunkptr next; /* next contiguous chunk after oldp */ INTERNAL_SIZE_T nextsize; /* its size */ mchunkptr prev; /* previous contiguous chunk before oldp */ INTERNAL_SIZE_T prevsize; /* its size */ mchunkptr remainder; /* holds split off extra space from newp */ INTERNAL_SIZE_T remainder_size; /* its size */ mchunkptr bck; /* misc temp for linking */ mchunkptr fwd; /* misc temp for linking */ check_inuse_chunk(ar_ptr, oldp); if ((long)(oldsize) < (long)(nb)) { Void_t* oldmem = BOUNDED_N(chunk2mem(oldp), oldsize); /* Try expanding forward */ next = chunk_at_offset(oldp, oldsize); if (next == top(ar_ptr) || !inuse(next)) { nextsize = chunksize(next); /* Forward into top only if a remainder */ if (next == top(ar_ptr)) { if ((long)(nextsize + newsize) >= (long)(nb + MINSIZE)) { newsize += nextsize; top(ar_ptr) = chunk_at_offset(oldp, nb); set_head(top(ar_ptr), (newsize - nb) | PREV_INUSE); set_head_size(oldp, nb); return oldp; } } /* Forward into next chunk */ else if (((long)(nextsize + newsize) >= (long)(nb))) { unlink(next, bck, fwd); newsize += nextsize; goto split; } } else { next = 0; nextsize = 0; } oldsize -= SIZE_SZ; /* Try shifting backwards. */ if (!prev_inuse(oldp)) { prev = prev_chunk(oldp); prevsize = chunksize(prev); /* try forward + backward first to save a later consolidation */ if (next != 0) { /* into top */ if (next == top(ar_ptr)) { if ((long)(nextsize + prevsize + newsize) >= (long)(nb + MINSIZE)) { unlink(prev, bck, fwd); newp = prev; newsize += prevsize + nextsize; MALLOC_COPY(BOUNDED_N(chunk2mem(newp), oldsize), oldmem, oldsize, 1); top(ar_ptr) = chunk_at_offset(newp, nb); set_head(top(ar_ptr), (newsize - nb) | PREV_INUSE); set_head_size(newp, nb); return newp; } } /* into next chunk */ else if (((long)(nextsize + prevsize + newsize) >= (long)(nb))) { unlink(next, bck, fwd); unlink(prev, bck, fwd); newp = prev; newsize += nextsize + prevsize; MALLOC_COPY(BOUNDED_N(chunk2mem(newp), oldsize), oldmem, oldsize, 1); goto split; } } /* backward only */ if (prev != 0 && (long)(prevsize + newsize) >= (long)nb) { unlink(prev, bck, fwd); newp = prev; newsize += prevsize; MALLOC_COPY(BOUNDED_N(chunk2mem(newp), oldsize), oldmem, oldsize, 1); goto split; } } /* Must allocate */ newp = chunk_alloc (ar_ptr, nb); if (newp == 0) { /* Maybe the failure is due to running out of mmapped areas. */ if (ar_ptr != &main_arena) { (void)mutex_lock(&main_arena.mutex); newp = chunk_alloc(&main_arena, nb); (void)mutex_unlock(&main_arena.mutex); } else { #if USE_ARENAS /* ... or sbrk() has failed and there is still a chance to mmap() */ arena* ar_ptr2 = arena_get2(ar_ptr->next ? ar_ptr : 0, nb); if(ar_ptr2) { newp = chunk_alloc(ar_ptr2, nb); (void)mutex_unlock(&ar_ptr2->mutex); } #endif } if (newp == 0) /* propagate failure */ return 0; } /* Avoid copy if newp is next chunk after oldp. */ /* (This can only happen when new chunk is sbrk'ed.) */ if ( newp == next_chunk(oldp)) { newsize += chunksize(newp); newp = oldp; goto split; } /* Otherwise copy, free, and exit */ MALLOC_COPY(BOUNDED_N(chunk2mem(newp), oldsize), oldmem, oldsize, 0); chunk_free(ar_ptr, oldp); return newp; } split: /* split off extra room in old or expanded chunk */ if (newsize - nb >= MINSIZE) /* split off remainder */ { remainder = chunk_at_offset(newp, nb); remainder_size = newsize - nb; set_head_size(newp, nb); set_head(remainder, remainder_size | PREV_INUSE); set_inuse_bit_at_offset(remainder, remainder_size); chunk_free(ar_ptr, remainder); } else { set_head_size(newp, newsize); set_inuse_bit_at_offset(newp, newsize); } check_inuse_chunk(ar_ptr, newp); return newp; } /* memalign algorithm: memalign requests more than enough space from malloc, finds a spot within that chunk that meets the alignment request, and then possibly frees the leading and trailing space. The alignment argument must be a power of two. This property is not checked by memalign, so misuse may result in random runtime errors. 8-byte alignment is guaranteed by normal malloc calls, so don't bother calling memalign with an argument of 8 or less. Overreliance on memalign is a sure way to fragment space. */ #if __STD_C Void_t* mEMALIGn(size_t alignment, size_t bytes) #else Void_t* mEMALIGn(alignment, bytes) size_t alignment; size_t bytes; #endif { arena *ar_ptr; INTERNAL_SIZE_T nb; /* padded request size */ mchunkptr p; #if defined _LIBC || defined MALLOC_HOOKS __malloc_ptr_t (*hook) __MALLOC_PMT ((size_t, size_t, __const __malloc_ptr_t)) = __memalign_hook; if (hook != NULL) { Void_t* result; #if defined __GNUC__ && __GNUC__ >= 2 result = (*hook)(alignment, bytes, RETURN_ADDRESS (0)); #else result = (*hook)(alignment, bytes, NULL); #endif return result; } #endif /* 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; if(request2size(bytes, nb)) return 0; arena_get(ar_ptr, nb + alignment + MINSIZE); if(!ar_ptr) return 0; p = chunk_align(ar_ptr, nb, alignment); (void)mutex_unlock(&ar_ptr->mutex); if(!p) { /* Maybe the failure is due to running out of mmapped areas. */ if(ar_ptr != &main_arena) { (void)mutex_lock(&main_arena.mutex); p = chunk_align(&main_arena, nb, alignment); (void)mutex_unlock(&main_arena.mutex); } else { #if USE_ARENAS /* ... or sbrk() has failed and there is still a chance to mmap() */ ar_ptr = arena_get2(ar_ptr->next ? ar_ptr : 0, nb); if(ar_ptr) { p = chunk_align(ar_ptr, nb, alignment); (void)mutex_unlock(&ar_ptr->mutex); } #endif } if(!p) return 0; } return BOUNDED_N(chunk2mem(p), bytes); } static mchunkptr internal_function #if __STD_C chunk_align(arena* ar_ptr, INTERNAL_SIZE_T nb, size_t alignment) #else chunk_align(ar_ptr, nb, alignment) arena* ar_ptr; INTERNAL_SIZE_T nb; size_t alignment; #endif { unsigned long 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 */ /* Call chunk_alloc with worst case padding to hit alignment. */ p = chunk_alloc(ar_ptr, nb + alignment + MINSIZE); if (p == 0) return 0; /* propagate failure */ m = (unsigned long)chunk2mem(p); if ((m % alignment) == 0) /* aligned */ { #if HAVE_MMAP if(chunk_is_mmapped(p)) { return p; /* nothing more to do */ } #endif } else /* misaligned */ { /* Find an aligned spot inside chunk. Since we need to give back leading space in a chunk of at least MINSIZE, if the first calculation places us at a spot with less than MINSIZE leader, we can move to the next aligned spot -- we've allocated enough total room so that this is always possible. */ brk = (char*)mem2chunk(((m + alignment - 1)) & -(long)alignment); if ((long)(brk - (char*)(p)) < (long)MINSIZE) brk += alignment; newp = chunk_at_offset(brk, 0); leadsize = brk - (char*)(p); newsize = chunksize(p) - leadsize; #if HAVE_MMAP if(chunk_is_mmapped(p)) { newp->prev_size = p->prev_size + leadsize; set_head(newp, newsize|IS_MMAPPED); return newp; } #endif /* give back leader, use the rest */ set_head(newp, newsize | PREV_INUSE); set_inuse_bit_at_offset(newp, newsize); set_head_size(p, leadsize); chunk_free(ar_ptr, p); p = newp; assert (newsize>=nb && (((unsigned long)(chunk2mem(p))) % alignment) == 0); } /* Also give back spare room at the end */ remainder_size = chunksize(p) - nb; if (remainder_size >= (long)MINSIZE) { remainder = chunk_at_offset(p, nb); set_head(remainder, remainder_size | PREV_INUSE); set_head_size(p, nb); chunk_free(ar_ptr, remainder); } check_inuse_chunk(ar_ptr, p); return p; } /* valloc just invokes memalign with alignment argument equal to the page size of the system (or as near to this as can be figured out from all the includes/defines above.) */ #if __STD_C Void_t* vALLOc(size_t bytes) #else Void_t* vALLOc(bytes) size_t bytes; #endif { if(__malloc_initialized < 0) ptmalloc_init (); return mEMALIGn (malloc_getpagesize, bytes); } /* pvalloc just invokes valloc for the nearest pagesize that will accommodate request */ #if __STD_C Void_t* pvALLOc(size_t bytes) #else Void_t* pvALLOc(bytes) size_t bytes; #endif { size_t pagesize; if(__malloc_initialized < 0) ptmalloc_init (); pagesize = malloc_getpagesize; return mEMALIGn (pagesize, (bytes + pagesize - 1) & ~(pagesize - 1)); } /* calloc calls chunk_alloc, then zeroes out the allocated chunk. */ #if __STD_C Void_t* cALLOc(size_t n, size_t elem_size) #else Void_t* cALLOc(n, elem_size) size_t n; size_t elem_size; #endif { arena *ar_ptr; mchunkptr p, oldtop; INTERNAL_SIZE_T sz, csz, oldtopsize; Void_t* mem; #if defined _LIBC || defined MALLOC_HOOKS __malloc_ptr_t (*hook) __MALLOC_PMT ((size_t, __const __malloc_ptr_t)) = __malloc_hook; if (hook != NULL) { sz = n * elem_size; #if defined __GNUC__ && __GNUC__ >= 2 mem = (*hook)(sz, RETURN_ADDRESS (0)); #else mem = (*hook)(sz, NULL); #endif if(mem == 0) return 0; #ifdef HAVE_MEMSET return memset(mem, 0, sz); #else while(sz > 0) ((char*)mem)[--sz] = 0; /* rather inefficient */ return mem; #endif } #endif if(request2size(n * elem_size, sz)) return 0; arena_get(ar_ptr, sz); if(!ar_ptr) return 0; /* Check if expand_top called, in which case there may be no need to clear. */ #if MORECORE_CLEARS oldtop = top(ar_ptr); oldtopsize = chunksize(top(ar_ptr)); #if MORECORE_CLEARS < 2 /* Only newly allocated memory is guaranteed to be cleared. */ if (ar_ptr == &main_arena && oldtopsize < sbrk_base + max_sbrked_mem - (char *)oldtop) oldtopsize = (sbrk_base + max_sbrked_mem - (char *)oldtop); #endif #endif p = chunk_alloc (ar_ptr, sz); /* Only clearing follows, so we can unlock early. */ (void)mutex_unlock(&ar_ptr->mutex); if (p == 0) { /* Maybe the failure is due to running out of mmapped areas. */ if(ar_ptr != &main_arena) { (void)mutex_lock(&main_arena.mutex); p = chunk_alloc(&main_arena, sz); (void)mutex_unlock(&main_arena.mutex); } else { #if USE_ARENAS /* ... or sbrk() has failed and there is still a chance to mmap() */ (void)mutex_lock(&main_arena.mutex); ar_ptr = arena_get2(ar_ptr->next ? ar_ptr : 0, sz); (void)mutex_unlock(&main_arena.mutex); if(ar_ptr) { p = chunk_alloc(ar_ptr, sz); (void)mutex_unlock(&ar_ptr->mutex); } #endif } if (p == 0) return 0; } mem = BOUNDED_N(chunk2mem(p), n * elem_size); /* Two optional cases in which clearing not necessary */ #if HAVE_MMAP if (chunk_is_mmapped(p)) return mem; #endif csz = chunksize(p); #if MORECORE_CLEARS if (p == oldtop && csz > oldtopsize) { /* clear only the bytes from non-freshly-sbrked memory */ csz = oldtopsize; } #endif csz -= SIZE_SZ; MALLOC_ZERO(BOUNDED_N(chunk2mem(p), csz), csz); return mem; } /* cfree just calls free. It is needed/defined on some systems that pair it with calloc, presumably for odd historical reasons. */ #if !defined(_LIBC) #if __STD_C void cfree(Void_t *mem) #else void cfree(mem) Void_t *mem; #endif { fREe(mem); } #endif /* Malloc_trim gives memory back to the system (via negative arguments to sbrk) if there is unused memory at the `high' end of the malloc pool. You can call this after freeing large blocks of memory to potentially reduce the system-level memory requirements of a program. However, it cannot guarantee to reduce memory. Under some allocation patterns, some large free blocks of memory will be locked between two used chunks, so they cannot be given back to the system. The `pad' argument to malloc_trim represents the amount of free trailing space to leave untrimmed. If this argument is zero, only the minimum amount of memory to maintain internal data structures will be left (one page or less). Non-zero arguments can be supplied to maintain enough trailing space to service future expected allocations without having to re-obtain memory from the system. Malloc_trim returns 1 if it actually released any memory, else 0. */ #if __STD_C int mALLOC_TRIm(size_t pad) #else int mALLOC_TRIm(pad) size_t pad; #endif { int res; (void)mutex_lock(&main_arena.mutex); res = main_trim(pad); (void)mutex_unlock(&main_arena.mutex); return res; } /* Trim the main arena. */ static int internal_function #if __STD_C main_trim(size_t pad) #else main_trim(pad) size_t pad; #endif { mchunkptr top_chunk; /* The current top chunk */ long top_size; /* Amount of top-most memory */ long extra; /* Amount to release */ char* current_brk; /* address returned by pre-check sbrk call */ char* new_brk; /* address returned by negative sbrk call */ unsigned long pagesz = malloc_getpagesize; top_chunk = top(&main_arena); top_size = chunksize(top_chunk); extra = ((top_size - pad - MINSIZE + (pagesz-1)) / pagesz - 1) * pagesz; if (extra < (long)pagesz) /* Not enough memory to release */ return 0; /* Test to make sure no one else called sbrk */ current_brk = (char*)(MORECORE (0)); if (current_brk != (char*)(top_chunk) + top_size) return 0; /* Apparently we don't own memory; must fail */ new_brk = (char*)(MORECORE (-extra)); #if defined _LIBC || defined MALLOC_HOOKS /* Call the `morecore' hook if necessary. */ if (__after_morecore_hook) (*__after_morecore_hook) (); #endif if (new_brk == (char*)(MORECORE_FAILURE)) { /* sbrk failed? */ /* Try to figure out what we have */ current_brk = (char*)(MORECORE (0)); top_size = current_brk - (char*)top_chunk; if (top_size >= (long)MINSIZE) /* if not, we are very very dead! */ { sbrked_mem = current_brk - sbrk_base; set_head(top_chunk, top_size | PREV_INUSE); } check_chunk(&main_arena, top_chunk); return 0; } sbrked_mem -= extra; /* Success. Adjust top accordingly. */ set_head(top_chunk, (top_size - extra) | PREV_INUSE); check_chunk(&main_arena, top_chunk); return 1; } #if USE_ARENAS static int internal_function #if __STD_C heap_trim(heap_info *heap, size_t pad) #else heap_trim(heap, pad) heap_info *heap; size_t pad; #endif { unsigned long pagesz = malloc_getpagesize; arena *ar_ptr = heap->ar_ptr; mchunkptr top_chunk = top(ar_ptr), p, bck, fwd; heap_info *prev_heap; long new_size, top_size, extra; /* Can this heap go away completely ? */ while(top_chunk == chunk_at_offset(heap, sizeof(*heap))) { prev_heap = heap->prev; p = chunk_at_offset(prev_heap, prev_heap->size - (MINSIZE-2*SIZE_SZ)); assert(p->size == (0|PREV_INUSE)); /* must be fencepost */ p = prev_chunk(p); new_size = chunksize(p) + (MINSIZE-2*SIZE_SZ); assert(new_size>0 && new_size<(long)(2*MINSIZE)); if(!prev_inuse(p)) new_size += p->prev_size; assert(new_size>0 && new_size<HEAP_MAX_SIZE); if(new_size + (HEAP_MAX_SIZE - prev_heap->size) < pad + MINSIZE + pagesz) break; ar_ptr->size -= heap->size; arena_mem -= heap->size; delete_heap(heap); heap = prev_heap; if(!prev_inuse(p)) { /* consolidate backward */ p = prev_chunk(p); unlink(p, bck, fwd); } assert(((unsigned long)((char*)p + new_size) & (pagesz-1)) == 0); assert( ((char*)p + new_size) == ((char*)heap + heap->size) ); top(ar_ptr) = top_chunk = p; set_head(top_chunk, new_size | PREV_INUSE); check_chunk(ar_ptr, top_chunk); } top_size = chunksize(top_chunk); extra = ((top_size - pad - MINSIZE + (pagesz-1))/pagesz - 1) * pagesz; if(extra < (long)pagesz) return 0; /* Try to shrink. */ if(grow_heap(heap, -extra) != 0) return 0; ar_ptr->size -= extra; arena_mem -= extra; /* Success. Adjust top accordingly. */ set_head(top_chunk, (top_size - extra) | PREV_INUSE); check_chunk(ar_ptr, top_chunk); return 1; } #endif /* USE_ARENAS */ /* malloc_usable_size: This routine tells you how many bytes you can actually use in an allocated chunk, which may be more than you requested (although often not). You can use this many bytes without worrying about overwriting other allocated objects. Not a particularly great programming practice, but still sometimes useful. */ #if __STD_C size_t mALLOC_USABLE_SIZe(Void_t* mem) #else size_t mALLOC_USABLE_SIZe(mem) Void_t* mem; #endif { mchunkptr p; if (mem == 0) return 0; else { p = mem2chunk(mem); if(!chunk_is_mmapped(p)) { if (!inuse(p)) return 0; check_inuse_chunk(arena_for_ptr(mem), p); return chunksize(p) - SIZE_SZ; } return chunksize(p) - 2*SIZE_SZ; } } /* Utility to update mallinfo for malloc_stats() and mallinfo() */ static void #if __STD_C malloc_update_mallinfo(arena *ar_ptr, struct mallinfo *mi) #else malloc_update_mallinfo(ar_ptr, mi) arena *ar_ptr; struct mallinfo *mi; #endif { int i, navail; mbinptr b; mchunkptr p; #if MALLOC_DEBUG mchunkptr q; #endif INTERNAL_SIZE_T avail; (void)mutex_lock(&ar_ptr->mutex); avail = chunksize(top(ar_ptr)); navail = ((long)(avail) >= (long)MINSIZE)? 1 : 0; for (i = 1; i < NAV; ++i) { b = bin_at(ar_ptr, i); for (p = last(b); p != b; p = p->bk) { #if MALLOC_DEBUG check_free_chunk(ar_ptr, p); for (q = next_chunk(p); q != top(ar_ptr) && inuse(q) && (long)chunksize(q) > 0; q = next_chunk(q)) check_inuse_chunk(ar_ptr, q); #endif avail += chunksize(p); navail++; } } mi->arena = ar_ptr->size; mi->ordblks = navail; mi->smblks = mi->usmblks = mi->fsmblks = 0; /* clear unused fields */ mi->uordblks = ar_ptr->size - avail; mi->fordblks = avail; mi->hblks = n_mmaps; mi->hblkhd = mmapped_mem; mi->keepcost = chunksize(top(ar_ptr)); (void)mutex_unlock(&ar_ptr->mutex); } #if USE_ARENAS && MALLOC_DEBUG > 1 /* Print the complete contents of a single heap to stderr. */ static void #if __STD_C dump_heap(heap_info *heap) #else dump_heap(heap) heap_info *heap; #endif { char *ptr; mchunkptr p; fprintf(stderr, "Heap %p, size %10lx:\n", heap, (long)heap->size); ptr = (heap->ar_ptr != (arena*)(heap+1)) ? (char*)(heap + 1) : (char*)(heap + 1) + sizeof(arena); p = (mchunkptr)(((unsigned long)ptr + MALLOC_ALIGN_MASK) & ~MALLOC_ALIGN_MASK); for(;;) { fprintf(stderr, "chunk %p size %10lx", p, (long)p->size); if(p == top(heap->ar_ptr)) { fprintf(stderr, " (top)\n"); break; } else if(p->size == (0|PREV_INUSE)) { fprintf(stderr, " (fence)\n"); break; } fprintf(stderr, "\n"); p = next_chunk(p); } } #endif /* malloc_stats: For all arenas separately and in total, prints on stderr the amount of space obtained from the system, 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.) When not compiled for multiple threads, the maximum amount of allocated memory (which may be more than current if malloc_trim and/or munmap got called) is also reported. When using mmap(), prints the maximum number of simultaneous mmap regions used, too. */ void mALLOC_STATs() { int i; arena *ar_ptr; struct mallinfo mi; unsigned int in_use_b = mmapped_mem, system_b = in_use_b; #if THREAD_STATS long stat_lock_direct = 0, stat_lock_loop = 0, stat_lock_wait = 0; #endif for(i=0, ar_ptr = &main_arena;; i++) { malloc_update_mallinfo(ar_ptr, &mi); fprintf(stderr, "Arena %d:\n", i); fprintf(stderr, "system bytes = %10u\n", (unsigned int)mi.arena); fprintf(stderr, "in use bytes = %10u\n", (unsigned int)mi.uordblks); system_b += mi.arena; in_use_b += mi.uordblks; #if THREAD_STATS stat_lock_direct += ar_ptr->stat_lock_direct; stat_lock_loop += ar_ptr->stat_lock_loop; stat_lock_wait += ar_ptr->stat_lock_wait; #endif #if USE_ARENAS && MALLOC_DEBUG > 1 if(ar_ptr != &main_arena) { heap_info *heap; (void)mutex_lock(&ar_ptr->mutex); heap = heap_for_ptr(top(ar_ptr)); while(heap) { dump_heap(heap); heap = heap->prev; } (void)mutex_unlock(&ar_ptr->mutex); } #endif ar_ptr = ar_ptr->next; if(ar_ptr == &main_arena) break; } #if HAVE_MMAP fprintf(stderr, "Total (incl. mmap):\n"); #else fprintf(stderr, "Total:\n"); #endif fprintf(stderr, "system bytes = %10u\n", system_b); fprintf(stderr, "in use bytes = %10u\n", in_use_b); #ifdef NO_THREADS fprintf(stderr, "max system bytes = %10u\n", (unsigned int)max_total_mem); #endif #if HAVE_MMAP fprintf(stderr, "max mmap regions = %10u\n", (unsigned int)max_n_mmaps); fprintf(stderr, "max mmap bytes = %10lu\n", max_mmapped_mem); #endif #if THREAD_STATS fprintf(stderr, "heaps created = %10d\n", stat_n_heaps); fprintf(stderr, "locked directly = %10ld\n", stat_lock_direct); fprintf(stderr, "locked in loop = %10ld\n", stat_lock_loop); fprintf(stderr, "locked waiting = %10ld\n", stat_lock_wait); fprintf(stderr, "locked total = %10ld\n", stat_lock_direct + stat_lock_loop + stat_lock_wait); #endif } /* mallinfo returns a copy of updated current mallinfo. The information reported is for the arena last used by the thread. */ struct mallinfo mALLINFo() { struct mallinfo mi; Void_t *vptr = NULL; #ifndef NO_THREADS tsd_getspecific(arena_key, vptr); if(vptr == ATFORK_ARENA_PTR) vptr = (Void_t*)&main_arena; #endif malloc_update_mallinfo((vptr ? (arena*)vptr : &main_arena), &mi); return mi; } /* mallopt: mallopt is the general SVID/XPG interface to tunable parameters. The format is to provide a (parameter-number, parameter-value) pair. mallopt then sets the corresponding parameter to the argument value if it can (i.e., so long as the value is meaningful), and returns 1 if successful else 0. See descriptions of tunable parameters above. */ #if __STD_C int mALLOPt(int param_number, int value) #else int mALLOPt(param_number, value) int param_number; int value; #endif { switch(param_number) { case M_TRIM_THRESHOLD: trim_threshold = value; return 1; case M_TOP_PAD: top_pad = value; return 1; case M_MMAP_THRESHOLD: #if USE_ARENAS /* Forbid setting the threshold too high. */ if((unsigned long)value > HEAP_MAX_SIZE/2) return 0; #endif mmap_threshold = value; return 1; case M_MMAP_MAX: #if HAVE_MMAP n_mmaps_max = value; return 1; #else if (value != 0) return 0; else n_mmaps_max = value; return 1; #endif case M_CHECK_ACTION: check_action = value; return 1; default: return 0; } } /* Get/set state: malloc_get_state() records the current state of all malloc variables (_except_ for the actual heap contents and `hook' function pointers) in a system dependent, opaque data structure. This data structure is dynamically allocated and can be free()d after use. malloc_set_state() restores the state of all malloc variables to the previously obtained state. This is especially useful when using this malloc as part of a shared library, and when the heap contents are saved/restored via some other method. The primary example for this is GNU Emacs with its `dumping' procedure. `Hook' function pointers are never saved or restored by these functions, with two exceptions: If malloc checking was in use when malloc_get_state() was called, then malloc_set_state() calls __malloc_check_init() if possible; if malloc checking was not in use in the recorded state but the user requested malloc checking, then the hooks are reset to 0. */ #define MALLOC_STATE_MAGIC 0x444c4541l #define MALLOC_STATE_VERSION (0*0x100l + 1l) /* major*0x100 + minor */ struct malloc_state { long magic; long version; mbinptr av[NAV * 2 + 2]; char* sbrk_base; int sbrked_mem_bytes; unsigned long trim_threshold; unsigned long top_pad; unsigned int n_mmaps_max; unsigned long mmap_threshold; int check_action; unsigned long max_sbrked_mem; unsigned long max_total_mem; unsigned int n_mmaps; unsigned int max_n_mmaps; unsigned long mmapped_mem; unsigned long max_mmapped_mem; int using_malloc_checking; }; Void_t* mALLOC_GET_STATe() { struct malloc_state* ms; int i; mbinptr b; ms = (struct malloc_state*)mALLOc(sizeof(*ms)); if (!ms) return 0; (void)mutex_lock(&main_arena.mutex); ms->magic = MALLOC_STATE_MAGIC; ms->version = MALLOC_STATE_VERSION; ms->av[0] = main_arena.av[0]; ms->av[1] = main_arena.av[1]; for(i=0; i<NAV; i++) { b = bin_at(&main_arena, i); if(first(b) == b) ms->av[2*i+2] = ms->av[2*i+3] = 0; /* empty bin (or initial top) */ else { ms->av[2*i+2] = first(b); ms->av[2*i+3] = last(b); } } ms->sbrk_base = sbrk_base; ms->sbrked_mem_bytes = sbrked_mem; ms->trim_threshold = trim_threshold; ms->top_pad = top_pad; ms->n_mmaps_max = n_mmaps_max; ms->mmap_threshold = mmap_threshold; ms->check_action = check_action; ms->max_sbrked_mem = max_sbrked_mem; #ifdef NO_THREADS ms->max_total_mem = max_total_mem; #else ms->max_total_mem = 0; #endif ms->n_mmaps = n_mmaps; ms->max_n_mmaps = max_n_mmaps; ms->mmapped_mem = mmapped_mem; ms->max_mmapped_mem = max_mmapped_mem; #if defined _LIBC || defined MALLOC_HOOKS ms->using_malloc_checking = using_malloc_checking; #else ms->using_malloc_checking = 0; #endif (void)mutex_unlock(&main_arena.mutex); return (Void_t*)ms; } int #if __STD_C mALLOC_SET_STATe(Void_t* msptr) #else mALLOC_SET_STATe(msptr) Void_t* msptr; #endif { struct malloc_state* ms = (struct malloc_state*)msptr; int i; mbinptr b; #if defined _LIBC || defined MALLOC_HOOKS disallow_malloc_check = 1; #endif ptmalloc_init(); if(ms->magic != MALLOC_STATE_MAGIC) return -1; /* Must fail if the major version is too high. */ if((ms->version & ~0xffl) > (MALLOC_STATE_VERSION & ~0xffl)) return -2; (void)mutex_lock(&main_arena.mutex); main_arena.av[0] = ms->av[0]; main_arena.av[1] = ms->av[1]; for(i=0; i<NAV; i++) { b = bin_at(&main_arena, i); if(ms->av[2*i+2] == 0) first(b) = last(b) = b; else { first(b) = ms->av[2*i+2]; last(b) = ms->av[2*i+3]; if(i > 0) { /* Make sure the links to the `av'-bins in the heap are correct. */ first(b)->bk = b; last(b)->fd = b; } } } sbrk_base = ms->sbrk_base; sbrked_mem = ms->sbrked_mem_bytes; trim_threshold = ms->trim_threshold; top_pad = ms->top_pad; n_mmaps_max = ms->n_mmaps_max; mmap_threshold = ms->mmap_threshold; check_action = ms->check_action; max_sbrked_mem = ms->max_sbrked_mem; #ifdef NO_THREADS max_total_mem = ms->max_total_mem; #endif n_mmaps = ms->n_mmaps; max_n_mmaps = ms->max_n_mmaps; mmapped_mem = ms->mmapped_mem; max_mmapped_mem = ms->max_mmapped_mem; /* add version-dependent code here */ if (ms->version >= 1) { #if defined _LIBC || defined MALLOC_HOOKS /* Check whether it is safe to enable malloc checking, or whether it is necessary to disable it. */ if (ms->using_malloc_checking && !using_malloc_checking && !disallow_malloc_check) __malloc_check_init (); else if (!ms->using_malloc_checking && using_malloc_checking) { __malloc_hook = 0; __free_hook = 0; __realloc_hook = 0; __memalign_hook = 0; using_malloc_checking = 0; } #endif } (void)mutex_unlock(&main_arena.mutex); return 0; } #if defined _LIBC || defined MALLOC_HOOKS /* A simple, standard set of debugging hooks. Overhead is `only' one byte per chunk; still this will catch most cases of double frees or overruns. The goal here is to avoid obscure crashes due to invalid usage, unlike in the MALLOC_DEBUG code. */ #define MAGICBYTE(p) ( ( ((size_t)p >> 3) ^ ((size_t)p >> 11)) & 0xFF ) /* Instrument a chunk with overrun detector byte(s) and convert it into a user pointer with requested size sz. */ static Void_t* internal_function #if __STD_C chunk2mem_check(mchunkptr p, size_t sz) #else chunk2mem_check(p, sz) mchunkptr p; size_t sz; #endif { unsigned char* m_ptr = (unsigned char*)BOUNDED_N(chunk2mem(p), sz); size_t i; for(i = chunksize(p) - (chunk_is_mmapped(p) ? 2*SIZE_SZ+1 : SIZE_SZ+1); i > sz; i -= 0xFF) { if(i-sz < 0x100) { m_ptr[i] = (unsigned char)(i-sz); break; } m_ptr[i] = 0xFF; } m_ptr[sz] = MAGICBYTE(p); return (Void_t*)m_ptr; } /* Convert a pointer to be free()d or realloc()ed to a valid chunk pointer. If the provided pointer is not valid, return NULL. */ static mchunkptr internal_function #if __STD_C mem2chunk_check(Void_t* mem) #else mem2chunk_check(mem) Void_t* mem; #endif { mchunkptr p; INTERNAL_SIZE_T sz, c; unsigned char magic; p = mem2chunk(mem); if(!aligned_OK(p)) return NULL; if( (char*)p>=sbrk_base && (char*)p<(sbrk_base+sbrked_mem) ) { /* Must be a chunk in conventional heap memory. */ if(chunk_is_mmapped(p) || ( (sz = chunksize(p)), ((char*)p + sz)>=(sbrk_base+sbrked_mem) ) || sz<MINSIZE || sz&MALLOC_ALIGN_MASK || !inuse(p) || ( !prev_inuse(p) && (p->prev_size&MALLOC_ALIGN_MASK || (long)prev_chunk(p)<(long)sbrk_base || next_chunk(prev_chunk(p))!=p) )) return NULL; magic = MAGICBYTE(p); for(sz += SIZE_SZ-1; (c = ((unsigned char*)p)[sz]) != magic; sz -= c) { if(c<=0 || sz<(c+2*SIZE_SZ)) return NULL; } ((unsigned char*)p)[sz] ^= 0xFF; } else { unsigned long offset, page_mask = malloc_getpagesize-1; /* mmap()ed chunks have MALLOC_ALIGNMENT or higher power-of-two alignment relative to the beginning of a page. Check this first. */ offset = (unsigned long)mem & page_mask; if((offset!=MALLOC_ALIGNMENT && offset!=0 && offset!=0x10 && offset!=0x20 && offset!=0x40 && offset!=0x80 && offset!=0x100 && offset!=0x200 && offset!=0x400 && offset!=0x800 && offset!=0x1000 && offset<0x2000) || !chunk_is_mmapped(p) || (p->size & PREV_INUSE) || ( (((unsigned long)p - p->prev_size) & page_mask) != 0 ) || ( (sz = chunksize(p)), ((p->prev_size + sz) & page_mask) != 0 ) ) return NULL; magic = MAGICBYTE(p); for(sz -= 1; (c = ((unsigned char*)p)[sz]) != magic; sz -= c) { if(c<=0 || sz<(c+2*SIZE_SZ)) return NULL; } ((unsigned char*)p)[sz] ^= 0xFF; } return p; } /* Check for corruption of the top chunk, and try to recover if necessary. */ static int internal_function #if __STD_C top_check(void) #else top_check() #endif { mchunkptr t = top(&main_arena); char* brk, * new_brk; INTERNAL_SIZE_T front_misalign, sbrk_size; unsigned long pagesz = malloc_getpagesize; if((char*)t + chunksize(t) == sbrk_base + sbrked_mem || t == initial_top(&main_arena)) return 0; if(check_action & 1) fprintf(stderr, "malloc: top chunk is corrupt\n"); if(check_action & 2) abort(); /* Try to set up a new top chunk. */ brk = MORECORE(0); front_misalign = (unsigned long)chunk2mem(brk) & MALLOC_ALIGN_MASK; if (front_misalign > 0) front_misalign = MALLOC_ALIGNMENT - front_misalign; sbrk_size = front_misalign + top_pad + MINSIZE; sbrk_size += pagesz - ((unsigned long)(brk + sbrk_size) & (pagesz - 1)); new_brk = (char*)(MORECORE (sbrk_size)); if (new_brk == (char*)(MORECORE_FAILURE)) return -1; sbrked_mem = (new_brk - sbrk_base) + sbrk_size; top(&main_arena) = (mchunkptr)(brk + front_misalign); set_head(top(&main_arena), (sbrk_size - front_misalign) | PREV_INUSE); return 0; } static Void_t* #if __STD_C malloc_check(size_t sz, const Void_t *caller) #else malloc_check(sz, caller) size_t sz; const Void_t *caller; #endif { mchunkptr victim; INTERNAL_SIZE_T nb; if(request2size(sz+1, nb)) return 0; (void)mutex_lock(&main_arena.mutex); victim = (top_check() >= 0) ? chunk_alloc(&main_arena, nb) : NULL; (void)mutex_unlock(&main_arena.mutex); if(!victim) return NULL; return chunk2mem_check(victim, sz); } static void #if __STD_C free_check(Void_t* mem, const Void_t *caller) #else free_check(mem, caller) Void_t* mem; const Void_t *caller; #endif { mchunkptr p; if(!mem) return; (void)mutex_lock(&main_arena.mutex); p = mem2chunk_check(mem); if(!p) { (void)mutex_unlock(&main_arena.mutex); if(check_action & 1) fprintf(stderr, "free(): invalid pointer %p!\n", mem); if(check_action & 2) abort(); return; } #if HAVE_MMAP if (chunk_is_mmapped(p)) { (void)mutex_unlock(&main_arena.mutex); munmap_chunk(p); return; } #endif #if 0 /* Erase freed memory. */ memset(mem, 0, chunksize(p) - (SIZE_SZ+1)); #endif chunk_free(&main_arena, p); (void)mutex_unlock(&main_arena.mutex); } static Void_t* #if __STD_C realloc_check(Void_t* oldmem, size_t bytes, const Void_t *caller) #else realloc_check(oldmem, bytes, caller) Void_t* oldmem; size_t bytes; const Void_t *caller; #endif { mchunkptr oldp, newp; INTERNAL_SIZE_T nb, oldsize; if (oldmem == 0) return malloc_check(bytes, NULL); (void)mutex_lock(&main_arena.mutex); oldp = mem2chunk_check(oldmem); if(!oldp) { (void)mutex_unlock(&main_arena.mutex); if(check_action & 1) fprintf(stderr, "realloc(): invalid pointer %p!\n", oldmem); if(check_action & 2) abort(); return malloc_check(bytes, NULL); } oldsize = chunksize(oldp); if(request2size(bytes+1, nb)) { (void)mutex_unlock(&main_arena.mutex); return 0; } #if HAVE_MMAP if (chunk_is_mmapped(oldp)) { #if HAVE_MREMAP newp = mremap_chunk(oldp, nb); if(!newp) { #endif /* Note the extra SIZE_SZ overhead. */ if(oldsize - SIZE_SZ >= nb) newp = oldp; /* do nothing */ else { /* Must alloc, copy, free. */ newp = (top_check() >= 0) ? chunk_alloc(&main_arena, nb) : NULL; if (newp) { MALLOC_COPY(BOUNDED_N(chunk2mem(newp), nb), oldmem, oldsize - 2*SIZE_SZ, 0); munmap_chunk(oldp); } } #if HAVE_MREMAP } #endif } else { #endif /* HAVE_MMAP */ newp = (top_check() >= 0) ? chunk_realloc(&main_arena, oldp, oldsize, nb) : NULL; #if 0 /* Erase freed memory. */ nb = chunksize(newp); if(oldp<newp || oldp>=chunk_at_offset(newp, nb)) { memset((char*)oldmem + 2*sizeof(mbinptr), 0, oldsize - (2*sizeof(mbinptr)+2*SIZE_SZ+1)); } else if(nb > oldsize+SIZE_SZ) { memset((char*)BOUNDED_N(chunk2mem(newp), bytes) + oldsize, 0, nb - (oldsize+SIZE_SZ)); } #endif #if HAVE_MMAP } #endif (void)mutex_unlock(&main_arena.mutex); if(!newp) return NULL; return chunk2mem_check(newp, bytes); } static Void_t* #if __STD_C memalign_check(size_t alignment, size_t bytes, const Void_t *caller) #else memalign_check(alignment, bytes, caller) size_t alignment; size_t bytes; const Void_t *caller; #endif { INTERNAL_SIZE_T nb; mchunkptr p; if (alignment <= MALLOC_ALIGNMENT) return malloc_check(bytes, NULL); if (alignment < MINSIZE) alignment = MINSIZE; if(request2size(bytes+1, nb)) return 0; (void)mutex_lock(&main_arena.mutex); p = (top_check() >= 0) ? chunk_align(&main_arena, nb, alignment) : NULL; (void)mutex_unlock(&main_arena.mutex); if(!p) return NULL; return chunk2mem_check(p, bytes); } #ifndef NO_THREADS /* The following hooks are used when the global initialization in ptmalloc_init() hasn't completed yet. */ static Void_t* #if __STD_C malloc_starter(size_t sz, const Void_t *caller) #else malloc_starter(sz, caller) size_t sz; const Void_t *caller; #endif { INTERNAL_SIZE_T nb; mchunkptr victim; if(request2size(sz, nb)) return 0; victim = chunk_alloc(&main_arena, nb); return victim ? BOUNDED_N(chunk2mem(victim), sz) : 0; } static void #if __STD_C free_starter(Void_t* mem, const Void_t *caller) #else free_starter(mem, caller) Void_t* mem; const Void_t *caller; #endif { mchunkptr p; if(!mem) return; p = mem2chunk(mem); #if HAVE_MMAP if (chunk_is_mmapped(p)) { munmap_chunk(p); return; } #endif chunk_free(&main_arena, p); } /* The following hooks are used while the `atfork' handling mechanism is active. */ static Void_t* #if __STD_C malloc_atfork (size_t sz, const Void_t *caller) #else malloc_atfork(sz, caller) size_t sz; const Void_t *caller; #endif { Void_t *vptr = NULL; INTERNAL_SIZE_T nb; mchunkptr victim; tsd_getspecific(arena_key, vptr); if(vptr == ATFORK_ARENA_PTR) { /* We are the only thread that may allocate at all. */ if(save_malloc_hook != malloc_check) { if(request2size(sz, nb)) return 0; victim = chunk_alloc(&main_arena, nb); return victim ? BOUNDED_N(chunk2mem(victim), sz) : 0; } else { if(top_check()<0 || request2size(sz+1, nb)) return 0; victim = chunk_alloc(&main_arena, nb); return victim ? chunk2mem_check(victim, sz) : 0; } } else { /* Suspend the thread until the `atfork' handlers have completed. By that time, the hooks will have been reset as well, so that mALLOc() can be used again. */ (void)mutex_lock(&list_lock); (void)mutex_unlock(&list_lock); return mALLOc(sz); } } static void #if __STD_C free_atfork(Void_t* mem, const Void_t *caller) #else free_atfork(mem, caller) Void_t* mem; const Void_t *caller; #endif { Void_t *vptr = NULL; arena *ar_ptr; mchunkptr p; /* chunk corresponding to mem */ if (mem == 0) /* free(0) has no effect */ return; p = mem2chunk(mem); /* do not bother to replicate free_check here */ #if HAVE_MMAP if (chunk_is_mmapped(p)) /* release mmapped memory. */ { munmap_chunk(p); return; } #endif ar_ptr = arena_for_ptr(p); tsd_getspecific(arena_key, vptr); if(vptr != ATFORK_ARENA_PTR) (void)mutex_lock(&ar_ptr->mutex); chunk_free(ar_ptr, p); if(vptr != ATFORK_ARENA_PTR) (void)mutex_unlock(&ar_ptr->mutex); } #endif /* !defined NO_THREADS */ #endif /* defined _LIBC || defined MALLOC_HOOKS */ #ifdef _LIBC /* default method of getting more storage */ __malloc_ptr_t __default_morecore (int inc) { __malloc_ptr_t result = (__malloc_ptr_t)sbrk (inc); if (result == (__malloc_ptr_t)-1) return NULL; return result; } /* We need a wrapper function for one of the additions of POSIX. */ int __posix_memalign (void **memptr, size_t alignment, size_t size) { void *mem; /* Test whether the ALIGNMENT argument is valid. It must be a power of two multiple of sizeof (void *). */ if (alignment % sizeof (void *) != 0 || (alignment & (alignment - 1)) != 0) return EINVAL; mem = __libc_memalign (alignment, size); if (mem != NULL) { *memptr = mem; return 0; } return ENOMEM; } weak_alias (__posix_memalign, posix_memalign) weak_alias (__libc_calloc, __calloc) weak_alias (__libc_calloc, calloc) weak_alias (__libc_free, __cfree) weak_alias (__libc_free, cfree) weak_alias (__libc_free, __free) weak_alias (__libc_free, free) weak_alias (__libc_malloc, __malloc) weak_alias (__libc_malloc, malloc) weak_alias (__libc_memalign, __memalign) weak_alias (__libc_memalign, memalign) weak_alias (__libc_realloc, __realloc) weak_alias (__libc_realloc, realloc) weak_alias (__libc_valloc, __valloc) weak_alias (__libc_valloc, valloc) weak_alias (__libc_pvalloc, __pvalloc) weak_alias (__libc_pvalloc, pvalloc) weak_alias (__libc_mallinfo, __mallinfo) weak_alias (__libc_mallinfo, mallinfo) weak_alias (__libc_mallopt, __mallopt) weak_alias (__libc_mallopt, mallopt) weak_alias (__malloc_stats, malloc_stats) weak_alias (__malloc_usable_size, malloc_usable_size) weak_alias (__malloc_trim, malloc_trim) weak_alias (__malloc_get_state, malloc_get_state) weak_alias (__malloc_set_state, malloc_set_state) #endif /* History: V2.6.4-pt3 Thu Feb 20 1997 Wolfram Gloger (wmglo@dent.med.uni-muenchen.de) * Added malloc_get/set_state() (mainly for use in GNU emacs), using interface from Marcus Daniels * All parameters are now adjustable via environment variables V2.6.4-pt2 Sat Dec 14 1996 Wolfram Gloger (wmglo@dent.med.uni-muenchen.de) * Added debugging hooks * Fixed possible deadlock in realloc() when out of memory * Don't pollute namespace in glibc: use __getpagesize, __mmap, etc. V2.6.4-pt Wed Dec 4 1996 Wolfram Gloger (wmglo@dent.med.uni-muenchen.de) * Very minor updates from the released 2.6.4 version. * Trimmed include file down to exported data structures. * Changes from H.J. Lu for glibc-2.0. V2.6.3i-pt Sep 16 1996 Wolfram Gloger (wmglo@dent.med.uni-muenchen.de) * Many changes for multiple threads * Introduced arenas and heaps 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 threshold * Eliminate block-local decls to simplify tracing and debugging. * Support another case of realloc via move into top * Fix error occurring 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.) */
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