diff options
Diffstat (limited to 'libc/stdlib/malloc-standard')
| -rw-r--r-- | libc/stdlib/malloc-standard/Makefile | 51 | ||||
| -rw-r--r-- | libc/stdlib/malloc-standard/calloc.c | 93 | ||||
| -rw-r--r-- | libc/stdlib/malloc-standard/free.c | 382 | ||||
| -rw-r--r-- | libc/stdlib/malloc-standard/mallinfo.c | 81 | ||||
| -rw-r--r-- | libc/stdlib/malloc-standard/malloc.c | 1160 | ||||
| -rw-r--r-- | libc/stdlib/malloc-standard/malloc.h | 953 | ||||
| -rw-r--r-- | libc/stdlib/malloc-standard/mallopt.c | 64 | ||||
| -rw-r--r-- | libc/stdlib/malloc-standard/memalign.c | 126 | ||||
| -rw-r--r-- | libc/stdlib/malloc-standard/realloc.c | 237 |
9 files changed, 3147 insertions, 0 deletions
diff --git a/libc/stdlib/malloc-standard/Makefile b/libc/stdlib/malloc-standard/Makefile new file mode 100644 index 000000000..2b87c5de2 --- /dev/null +++ b/libc/stdlib/malloc-standard/Makefile @@ -0,0 +1,51 @@ +# Makefile for uClibc +# +# Copyright (C) 2000 by Lineo, inc. +# Copyright (C) 2000,2001 Erik Andersen <andersen@uclibc.org> +# +# This program is free software; you can redistribute it and/or modify it under +# the terms of the GNU Library General Public License as published by the Free +# Software Foundation; either version 2 of the License, or (at your option) any +# later version. +# +# This program 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 Library General Public License for more +# details. +# +# You should have received a copy of the GNU Library General Public License +# along with this program; if not, write to the Free Software Foundation, Inc., +# 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA +# +# Derived in part from the Linux-8086 C library, the GNU C Library, and several +# other sundry sources. Files within this library are copyright by their +# respective copyright holders. + +TOPDIR=../../../ +include $(TOPDIR)Rules.mak + +# Turn on malloc debugging if requested +ifeq ($(UCLIBC_MALLOC_DEBUGGING),y) +CFLAGS += -D__MALLOC_DEBUGGING +endif + +# calloc.c can be found at uClibc/libc/stdlib/calloc.c +# valloc.c can be found at uClibc/libc/stdlib/valloc.c +CSRC=malloc.c calloc.c realloc.c free.c memalign.c mallopt.c mallinfo.c +COBJS=$(patsubst %.c,%.o, $(CSRC)) +OBJS=$(COBJS) + +all: $(OBJS) $(LIBC) + +$(LIBC): ar-target + +ar-target: $(OBJS) + $(AR) $(ARFLAGS) $(LIBC) $(OBJS) + +$(COBJS): %.o : %.c + $(CC) $(CFLAGS) -c $< -o $@ + $(STRIPTOOL) -x -R .note -R .comment $*.o + +clean: + $(RM) *.[oa] *~ core + diff --git a/libc/stdlib/malloc-standard/calloc.c b/libc/stdlib/malloc-standard/calloc.c new file mode 100644 index 000000000..cff0adab8 --- /dev/null +++ b/libc/stdlib/malloc-standard/calloc.c @@ -0,0 +1,93 @@ +/* + This is a version (aka dlmalloc) of malloc/free/realloc written by + Doug Lea and released to the public domain. Use, modify, and + redistribute this code without permission or acknowledgement in any + way you wish. Send questions, comments, complaints, performance + data, etc to dl@cs.oswego.edu + + VERSION 2.7.2 Sat Aug 17 09:07:30 2002 Doug Lea (dl at gee) + + Note: There may be an updated version of this malloc obtainable at + ftp://gee.cs.oswego.edu/pub/misc/malloc.c + Check before installing! + + Hacked up for uClibc by Erik Andersen <andersen@codepoet.org> +*/ + +#include "malloc.h" + + +/* ------------------------------ calloc ------------------------------ */ +void* calloc(size_t n_elements, size_t elem_size) +{ + mchunkptr p; + unsigned long clearsize; + unsigned long nclears; + size_t size, *d; + void* mem; + + + /* guard vs integer overflow, but allow nmemb + * to fall through and call malloc(0) */ + size=lsize * nmemb; + if (n_elements && elem_size != (size / n_elements)) { + __set_errno(ENOMEM); + return NULL; + } + + LOCK; + mem = malloc(size); + if (mem != 0) { + p = mem2chunk(mem); + + if (!chunk_is_mmapped(p)) + { + /* + Unroll clear of <= 36 bytes (72 if 8byte sizes) + We know that contents have an odd number of + size_t-sized words; minimally 3. + */ + + d = (size_t*)mem; + clearsize = chunksize(p) - (sizeof(size_t)); + nclears = clearsize / sizeof(size_t); + assert(nclears >= 3); + + if (nclears > 9) + memset(d, 0, clearsize); + + else { + *(d+0) = 0; + *(d+1) = 0; + *(d+2) = 0; + if (nclears > 4) { + *(d+3) = 0; + *(d+4) = 0; + if (nclears > 6) { + *(d+5) = 0; + *(d+6) = 0; + if (nclears > 8) { + *(d+7) = 0; + *(d+8) = 0; + } + } + } + } + } +#if 0 + else + { + /* Standard unix mmap using /dev/zero clears memory so calloc + * doesn't need to actually zero anything.... + */ + d = (size_t*)mem; + /* Note the additional (sizeof(size_t)) */ + clearsize = chunksize(p) - 2*(sizeof(size_t)); + memset(d, 0, clearsize); + } +#endif + } + UNLOCK; + return mem; +} + diff --git a/libc/stdlib/malloc-standard/free.c b/libc/stdlib/malloc-standard/free.c new file mode 100644 index 000000000..4277767fa --- /dev/null +++ b/libc/stdlib/malloc-standard/free.c @@ -0,0 +1,382 @@ +/* + This is a version (aka dlmalloc) of malloc/free/realloc written by + Doug Lea and released to the public domain. Use, modify, and + redistribute this code without permission or acknowledgement in any + way you wish. Send questions, comments, complaints, performance + data, etc to dl@cs.oswego.edu + + VERSION 2.7.2 Sat Aug 17 09:07:30 2002 Doug Lea (dl at gee) + + Note: There may be an updated version of this malloc obtainable at + ftp://gee.cs.oswego.edu/pub/misc/malloc.c + Check before installing! + + Hacked up for uClibc by Erik Andersen <andersen@codepoet.org> +*/ + +#include "malloc.h" + + +/* ------------------------- __malloc_trim ------------------------- + __malloc_trim is an inverse of sorts to __malloc_alloc. It gives memory + back to the system (via negative arguments to sbrk) if there is unused + memory at the `high' end of the malloc pool. It is called automatically by + free() when top space exceeds the trim threshold. It is also called by the + public malloc_trim routine. It returns 1 if it actually released any + memory, else 0. +*/ +static int __malloc_trim(size_t pad, mstate av) +{ + long top_size; /* Amount of top-most memory */ + long extra; /* Amount to release */ + long released; /* Amount actually released */ + char* current_brk; /* address returned by pre-check sbrk call */ + char* new_brk; /* address returned by post-check sbrk call */ + size_t pagesz; + + pagesz = av->pagesize; + top_size = chunksize(av->top); + + /* Release in pagesize units, keeping at least one page */ + extra = ((top_size - pad - MINSIZE + (pagesz-1)) / pagesz - 1) * pagesz; + + if (extra > 0) { + + /* + Only proceed if end of memory is where we last set it. + This avoids problems if there were foreign sbrk calls. + */ + current_brk = (char*)(MORECORE(0)); + if (current_brk == (char*)(av->top) + top_size) { + + /* + Attempt to release memory. We ignore MORECORE return value, + and instead call again to find out where new end of memory is. + This avoids problems if first call releases less than we asked, + of if failure somehow altered brk value. (We could still + encounter problems if it altered brk in some very bad way, + but the only thing we can do is adjust anyway, which will cause + some downstream failure.) + */ + + MORECORE(-extra); + new_brk = (char*)(MORECORE(0)); + + if (new_brk != (char*)MORECORE_FAILURE) { + released = (long)(current_brk - new_brk); + + if (released != 0) { + /* Success. Adjust top. */ + av->sbrked_mem -= released; + set_head(av->top, (top_size - released) | PREV_INUSE); + check_malloc_state(); + return 1; + } + } + } + } + return 0; +} + +/* + Initialize a malloc_state struct. + + This is called only from within __malloc_consolidate, which needs + be called in the same contexts anyway. It is never called directly + outside of __malloc_consolidate because some optimizing compilers try + to inline it at all call points, which turns out not to be an + optimization at all. (Inlining it in __malloc_consolidate is fine though.) +*/ +static void malloc_init_state(mstate av) +{ + int i; + mbinptr bin; + + /* Establish circular links for normal bins */ + for (i = 1; i < NBINS; ++i) { + bin = bin_at(av,i); + bin->fd = bin->bk = bin; + } + + av->top_pad = DEFAULT_TOP_PAD; + av->n_mmaps_max = DEFAULT_MMAP_MAX; + av->mmap_threshold = DEFAULT_MMAP_THRESHOLD; + av->trim_threshold = DEFAULT_TRIM_THRESHOLD; + +#if MORECORE_CONTIGUOUS + set_contiguous(av); +#else + set_noncontiguous(av); +#endif + + + set_max_fast(av, DEFAULT_MXFAST); + + av->top = initial_top(av); + av->pagesize = malloc_getpagesize; +} + + +/* ---------------------------------------------------------------------- + * + * PUBLIC STUFF + * + * ----------------------------------------------------------------------*/ + + +/* ------------------------- __malloc_consolidate ------------------------- + + __malloc_consolidate is a specialized version of free() that tears + down chunks held in fastbins. Free itself cannot be used for this + purpose since, among other things, it might place chunks back onto + fastbins. So, instead, we need to use a minor variant of the same + code. + + Also, because this routine needs to be called the first time through + malloc anyway, it turns out to be the perfect place to trigger + initialization code. +*/ +void __malloc_consolidate(mstate av) +{ + mfastbinptr* fb; /* current fastbin being consolidated */ + mfastbinptr* maxfb; /* last fastbin (for loop control) */ + mchunkptr p; /* current chunk being consolidated */ + mchunkptr nextp; /* next chunk to consolidate */ + mchunkptr unsorted_bin; /* bin header */ + mchunkptr first_unsorted; /* chunk to link to */ + + /* These have same use as in free() */ + mchunkptr nextchunk; + size_t size; + size_t nextsize; + size_t prevsize; + int nextinuse; + mchunkptr bck; + mchunkptr fwd; + + /* + If max_fast is 0, we know that av hasn't + yet been initialized, in which case do so below + */ + + if (av->max_fast != 0) { + clear_fastchunks(av); + + unsorted_bin = unsorted_chunks(av); + + /* + Remove each chunk from fast bin and consolidate it, placing it + then in unsorted bin. Among other reasons for doing this, + placing in unsorted bin avoids needing to calculate actual bins + until malloc is sure that chunks aren't immediately going to be + reused anyway. + */ + + maxfb = &(av->fastbins[fastbin_index(av->max_fast)]); + fb = &(av->fastbins[0]); + do { + if ( (p = *fb) != 0) { + *fb = 0; + + do { + check_inuse_chunk(p); + nextp = p->fd; + + /* Slightly streamlined version of consolidation code in free() */ + size = p->size & ~PREV_INUSE; + nextchunk = chunk_at_offset(p, size); + nextsize = chunksize(nextchunk); + + if (!prev_inuse(p)) { + prevsize = p->prev_size; + size += prevsize; + p = chunk_at_offset(p, -((long) prevsize)); + unlink(p, bck, fwd); + } + + if (nextchunk != av->top) { + nextinuse = inuse_bit_at_offset(nextchunk, nextsize); + set_head(nextchunk, nextsize); + + if (!nextinuse) { + size += nextsize; + unlink(nextchunk, bck, fwd); + } + + first_unsorted = unsorted_bin->fd; + unsorted_bin->fd = p; + first_unsorted->bk = p; + + set_head(p, size | PREV_INUSE); + p->bk = unsorted_bin; + p->fd = first_unsorted; + set_foot(p, size); + } + + else { + size += nextsize; + set_head(p, size | PREV_INUSE); + av->top = p; + } + + } while ( (p = nextp) != 0); + + } + } while (fb++ != maxfb); + } + else { + malloc_init_state(av); + check_malloc_state(); + } +} + + +/* ------------------------------ free ------------------------------ */ +void free(void* mem) +{ + mstate av; + + mchunkptr p; /* chunk corresponding to mem */ + size_t size; /* its size */ + mfastbinptr* fb; /* associated fastbin */ + mchunkptr nextchunk; /* next contiguous chunk */ + size_t nextsize; /* its size */ + int nextinuse; /* true if nextchunk is used */ + size_t prevsize; /* size of previous contiguous chunk */ + mchunkptr bck; /* misc temp for linking */ + mchunkptr fwd; /* misc temp for linking */ + + /* free(0) has no effect */ + if (mem == NULL) + return; + + LOCK; + av = get_malloc_state(); + p = mem2chunk(mem); + size = chunksize(p); + + check_inuse_chunk(p); + + /* + If eligible, place chunk on a fastbin so it can be found + and used quickly in malloc. + */ + + if ((unsigned long)(size) <= (unsigned long)(av->max_fast) + +#if TRIM_FASTBINS + /* If TRIM_FASTBINS set, don't place chunks + bordering top into fastbins */ + && (chunk_at_offset(p, size) != av->top) +#endif + ) { + + set_fastchunks(av); + fb = &(av->fastbins[fastbin_index(size)]); + p->fd = *fb; + *fb = p; + } + + /* + Consolidate other non-mmapped chunks as they arrive. + */ + + else if (!chunk_is_mmapped(p)) { + set_anychunks(av); + + nextchunk = chunk_at_offset(p, size); + nextsize = chunksize(nextchunk); + + /* consolidate backward */ + if (!prev_inuse(p)) { + prevsize = p->prev_size; + size += prevsize; + p = chunk_at_offset(p, -((long) prevsize)); + unlink(p, bck, fwd); + } + + if (nextchunk != av->top) { + /* get and clear inuse bit */ + nextinuse = inuse_bit_at_offset(nextchunk, nextsize); + set_head(nextchunk, nextsize); + + /* consolidate forward */ + if (!nextinuse) { + unlink(nextchunk, bck, fwd); + size += nextsize; + } + + /* + Place the chunk in unsorted chunk list. Chunks are + not placed into regular bins until after they have + been given one chance to be used in malloc. + */ + + bck = unsorted_chunks(av); + fwd = bck->fd; + p->bk = bck; + p->fd = fwd; + bck->fd = p; + fwd->bk = p; + + set_head(p, size | PREV_INUSE); + set_foot(p, size); + + check_free_chunk(p); + } + + /* + If the chunk borders the current high end of memory, + consolidate into top + */ + + else { + size += nextsize; + set_head(p, size | PREV_INUSE); + av->top = p; + check_chunk(p); + } + + /* + If freeing a large space, consolidate possibly-surrounding + chunks. Then, if the total unused topmost memory exceeds trim + threshold, ask malloc_trim to reduce top. + + Unless max_fast is 0, we don't know if there are fastbins + bordering top, so we cannot tell for sure whether threshold + has been reached unless fastbins are consolidated. But we + don't want to consolidate on each free. As a compromise, + consolidation is performed if FASTBIN_CONSOLIDATION_THRESHOLD + is reached. + */ + + if ((unsigned long)(size) >= FASTBIN_CONSOLIDATION_THRESHOLD) { + if (have_fastchunks(av)) + __malloc_consolidate(av); + + if ((unsigned long)(chunksize(av->top)) >= + (unsigned long)(av->trim_threshold)) + __malloc_trim(av->top_pad, av); + } + + } + /* + If the chunk was allocated via mmap, release via munmap() + Note that if HAVE_MMAP is false but chunk_is_mmapped is + true, then user must have overwritten memory. There's nothing + we can do to catch this error unless DEBUG is set, in which case + check_inuse_chunk (above) will have triggered error. + */ + + else { + int ret; + size_t offset = p->prev_size; + av->n_mmaps--; + av->mmapped_mem -= (size + offset); + ret = munmap((char*)p - offset, size + offset); + /* munmap returns non-zero on failure */ + assert(ret == 0); + } + UNLOCK; +} + diff --git a/libc/stdlib/malloc-standard/mallinfo.c b/libc/stdlib/malloc-standard/mallinfo.c new file mode 100644 index 000000000..89d6b68e1 --- /dev/null +++ b/libc/stdlib/malloc-standard/mallinfo.c @@ -0,0 +1,81 @@ +/* + This is a version (aka dlmalloc) of malloc/free/realloc written by + Doug Lea and released to the public domain. Use, modify, and + redistribute this code without permission or acknowledgement in any + way you wish. Send questions, comments, complaints, performance + data, etc to dl@cs.oswego.edu + + VERSION 2.7.2 Sat Aug 17 09:07:30 2002 Doug Lea (dl at gee) + + Note: There may be an updated version of this malloc obtainable at + ftp://gee.cs.oswego.edu/pub/misc/malloc.c + Check before installing! + + Hacked up for uClibc by Erik Andersen <andersen@codepoet.org> +*/ + +#include "malloc.h" + + +/* ------------------------------ mallinfo ------------------------------ */ +struct mallinfo mallinfo(void) +{ + mstate av; + struct mallinfo mi; + int i; + mbinptr b; + mchunkptr p; + size_t avail; + size_t fastavail; + int nblocks; + int nfastblocks; + + LOCK; + av = get_malloc_state(); + /* Ensure initialization */ + if (av->top == 0) { + __malloc_consolidate(av); + } + + check_malloc_state(); + + /* Account for top */ + avail = chunksize(av->top); + nblocks = 1; /* top always exists */ + + /* traverse fastbins */ + nfastblocks = 0; + fastavail = 0; + + for (i = 0; i < NFASTBINS; ++i) { + for (p = av->fastbins[i]; p != 0; p = p->fd) { + ++nfastblocks; + fastavail += chunksize(p); + } + } + + avail += fastavail; + + /* traverse regular bins */ + for (i = 1; i < NBINS; ++i) { + b = bin_at(av, i); + for (p = last(b); p != b; p = p->bk) { + ++nblocks; + avail += chunksize(p); + } + } + + mi.smblks = nfastblocks; + mi.ordblks = nblocks; + mi.fordblks = avail; + mi.uordblks = av->sbrked_mem - avail; + mi.arena = av->sbrked_mem; + mi.hblks = av->n_mmaps; + mi.hblkhd = av->mmapped_mem; + mi.fsmblks = fastavail; + mi.keepcost = chunksize(av->top); + mi.usmblks = av->max_total_mem; + UNLOCK; + return mi; +} + diff --git a/libc/stdlib/malloc-standard/malloc.c b/libc/stdlib/malloc-standard/malloc.c new file mode 100644 index 000000000..8d132a43e --- /dev/null +++ b/libc/stdlib/malloc-standard/malloc.c @@ -0,0 +1,1160 @@ +/* + This is a version (aka dlmalloc) of malloc/free/realloc written by + Doug Lea and released to the public domain. Use, modify, and + redistribute this code without permission or acknowledgement in any + way you wish. Send questions, comments, complaints, performance + data, etc to dl@cs.oswego.edu + + VERSION 2.7.2 Sat Aug 17 09:07:30 2002 Doug Lea (dl at gee) + + Note: There may be an updated version of this malloc obtainable at + ftp://gee.cs.oswego.edu/pub/misc/malloc.c + Check before installing! + + Hacked up for uClibc by Erik Andersen <andersen@codepoet.org> +*/ + +#define _GNU_SOURCE +#include "malloc.h" + + +#ifdef __UCLIBC_HAS_THREADS__ +pthread_mutex_t __malloc_lock = PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP; +#endif + +/* + There is exactly one instance of this struct in this malloc. + If you are adapting this malloc in a way that does NOT use a static + malloc_state, you MUST explicitly zero-fill it before using. This + malloc relies on the property that malloc_state is initialized to + all zeroes (as is true of C statics). +*/ +struct malloc_state __malloc_state; /* never directly referenced */ + +/* forward declaration */ +static int __malloc_largebin_index(unsigned int sz); + +#ifdef __MALLOC_DEBUGGING + +/* + Debugging support + + Because freed chunks may be overwritten with bookkeeping fields, this + malloc will often die when freed memory is overwritten by user + programs. This can be very effective (albeit in an annoying way) + in helping track down dangling pointers. + + If you compile with -D__MALLOC_DEBUGGING, 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_DEBUGGING set will + attempt to check every non-mmapped allocated and free chunk in the + course of computing the summmaries. (By nature, mmapped regions + cannot be checked very much automatically.) + + Setting __MALLOC_DEBUGGING 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. + + Setting __MALLOC_DEBUGGING does NOT provide an automated mechanism for checking + that all accesses to malloced memory stay within their + bounds. However, there are several add-ons and adaptations of this + or other mallocs available that do this. +*/ + +/* Properties of all chunks */ +void __do_check_chunk(mchunkptr p) +{ + mstate av = get_malloc_state(); +#ifdef __DOASSERTS__ + /* min and max possible addresses assuming contiguous allocation */ + char* max_address = (char*)(av->top) + chunksize(av->top); + char* min_address = max_address - av->sbrked_mem; + unsigned long sz = chunksize(p); +#endif + + if (!chunk_is_mmapped(p)) { + + /* Has legal address ... */ + if (p != av->top) { + if (contiguous(av)) { + assert(((char*)p) >= min_address); + assert(((char*)p + sz) <= ((char*)(av->top))); + } + } + else { + /* top size is always at least MINSIZE */ + assert((unsigned long)(sz) >= MINSIZE); + /* top predecessor always marked inuse */ + assert(prev_inuse(p)); + } + + } + else { + /* address is outside main heap */ + if (contiguous(av) && av->top != initial_top(av)) { + assert(((char*)p) < min_address || ((char*)p) > max_address); + } + /* chunk is page-aligned */ + assert(((p->prev_size + sz) & (av->pagesize-1)) == 0); + /* mem is aligned */ + assert(aligned_OK(chunk2mem(p))); + } +} + +/* Properties of free chunks */ +void __do_check_free_chunk(mchunkptr p) +{ + size_t sz = p->size & ~PREV_INUSE; +#ifdef __DOASSERTS__ + mstate av = get_malloc_state(); + mchunkptr next = chunk_at_offset(p, sz); +#endif + + __do_check_chunk(p); + + /* Chunk must claim to be free ... */ + assert(!inuse(p)); + assert (!chunk_is_mmapped(p)); + + /* Unless a special marker, must have OK fields */ + if ((unsigned long)(sz) >= MINSIZE) + { + assert((sz & MALLOC_ALIGN_MASK) == 0); + assert(aligned_OK(chunk2mem(p))); + /* ... matching footer field */ + assert(next->prev_size == sz); + /* ... and is fully consolidated */ + assert(prev_inuse(p)); + assert (next == av->top || inuse(next)); + + /* ... and has minimally sane links */ + assert(p->fd->bk == p); + assert(p->bk->fd == p); + } + else /* markers are always of size (sizeof(size_t)) */ + assert(sz == (sizeof(size_t))); +} + +/* Properties of inuse chunks */ +void __do_check_inuse_chunk(mchunkptr p) +{ + mstate av = get_malloc_state(); + mchunkptr next; + __do_check_chunk(p); + + if (chunk_is_mmapped(p)) + return; /* mmapped chunks have no next/prev */ + + /* Check whether it claims to be in use ... */ + assert(inuse(p)); + + next = next_chunk(p); + + /* ... and is surrounded by OK chunks. + Since more things can be checked with free chunks than inuse ones, + if an inuse chunk borders them and debug is on, it's worth doing them. + */ + if (!prev_inuse(p)) { + /* Note that we cannot even look at prev unless it is not inuse */ + mchunkptr prv = prev_chunk(p); + assert(next_chunk(prv) == p); + __do_check_free_chunk(prv); + } + + if (next == av->top) { + assert(prev_inuse(next)); + assert(chunksize(next) >= MINSIZE); + } + else if (!inuse(next)) + __do_check_free_chunk(next); +} + +/* Properties of chunks recycled from fastbins */ +void __do_check_remalloced_chunk(mchunkptr p, size_t s) +{ +#ifdef __DOASSERTS__ + size_t sz = p->size & ~PREV_INUSE; +#endif + + __do_check_inuse_chunk(p); + + /* Legal size ... */ + assert((sz & MALLOC_ALIGN_MASK) == 0); + assert((unsigned long)(sz) >= MINSIZE); + /* ... and alignment */ + assert(aligned_OK(chunk2mem(p))); + /* chunk is less than MINSIZE more than request */ + assert((long)(sz) - (long)(s) >= 0); + assert((long)(sz) - (long)(s + MINSIZE) < 0); +} + +/* Properties of nonrecycled chunks at the point they are malloced */ +void __do_check_malloced_chunk(mchunkptr p, size_t s) +{ + /* same as recycled case ... */ + __do_check_remalloced_chunk(p, s); + + /* + ... plus, must obey implementation invariant that prev_inuse is + always true of any allocated chunk; i.e., that each allocated + chunk borders either a previously allocated and still in-use + chunk, or the base of its memory arena. This is ensured + by making all allocations from the the `lowest' part of any found + chunk. This does not necessarily hold however for chunks + recycled via fastbins. + */ + + assert(prev_inuse(p)); +} + + +/* + Properties of malloc_state. + + This may be useful for debugging malloc, as well as detecting user + programmer errors that somehow write into malloc_state. + + If you are extending or experimenting with this malloc, you can + probably figure out how to hack this routine to print out or + display chunk addresses, sizes, bins, and other instrumentation. +*/ +void __do_check_malloc_state(void) +{ + mstate av = get_malloc_state(); + int i; + mchunkptr p; + mchunkptr q; + mbinptr b; + unsigned int binbit; + int empty; + unsigned int idx; + size_t size; + unsigned long total = 0; + int max_fast_bin; + + /* internal size_t must be no wider than pointer type */ + assert(sizeof(size_t) <= sizeof(char*)); + + /* alignment is a power of 2 */ + assert((MALLOC_ALIGNMENT & (MALLOC_ALIGNMENT-1)) == 0); + + /* cannot run remaining checks until fully initialized */ + if (av->top == 0 || av->top == initial_top(av)) + return; + + /* pagesize is a power of 2 */ + assert((av->pagesize & (av->pagesize-1)) == 0); + + /* properties of fastbins */ + + /* max_fast is in allowed range */ + assert(get_max_fast(av) <= request2size(MAX_FAST_SIZE)); + + max_fast_bin = fastbin_index(av->max_fast); + + for (i = 0; i < NFASTBINS; ++i) { + p = av->fastbins[i]; + + /* all bins past max_fast are empty */ + if (i > max_fast_bin) + assert(p == 0); + + while (p != 0) { + /* each chunk claims to be inuse */ + __do_check_inuse_chunk(p); + total += chunksize(p); + /* chunk belongs in this bin */ + assert(fastbin_index(chunksize(p)) == i); + p = p->fd; + } + } + + if (total != 0) + assert(have_fastchunks(av)); + else if (!have_fastchunks(av)) + assert(total == 0); + + /* check normal bins */ + for (i = 1; i < NBINS; ++i) { + b = bin_at(av,i); + + /* binmap is accurate (except for bin 1 == unsorted_chunks) */ + if (i >= 2) { + binbit = get_binmap(av,i); + empty = last(b) == b; + if (!binbit) + assert(empty); + else if (!empty) + assert(binbit); + } + + for (p = last(b); p != b; p = p->bk) { + /* each chunk claims to be free */ + __do_check_free_chunk(p); + size = chunksize(p); + total += size; + if (i >= 2) { + /* chunk belongs in bin */ + idx = bin_index(size); + assert(idx == i); + /* lists are sorted */ + if ((unsigned long) size >= (unsigned long)(FIRST_SORTED_BIN_SIZE)) { + assert(p->bk == b || + (unsigned long)chunksize(p->bk) >= + (unsigned long)chunksize(p)); + } + } + /* chunk is followed by a legal chain of inuse chunks */ + for (q = next_chunk(p); + (q != av->top && inuse(q) && + (unsigned long)(chunksize(q)) >= MINSIZE); + q = next_chunk(q)) + __do_check_inuse_chunk(q); + } + } + + /* top chunk is OK */ + __do_check_chunk(av->top); + + /* sanity checks for statistics */ + + assert(total <= (unsigned long)(av->max_total_mem)); + assert(av->n_mmaps >= 0); + assert(av->n_mmaps <= av->max_n_mmaps); + + assert((unsigned long)(av->sbrked_mem) <= + (unsigned long)(av->max_sbrked_mem)); + + assert((unsigned long)(av->mmapped_mem) <= + (unsigned long)(av->max_mmapped_mem)); + + assert((unsigned long)(av->max_total_mem) >= + (unsigned long)(av->mmapped_mem) + (unsigned long)(av->sbrked_mem)); +} +#endif + + +/* ----------- Routines dealing with system allocation -------------- */ + +/* + sysmalloc handles malloc cases requiring more memory from the system. + On entry, it is assumed that av->top does not have enough + space to service request for nb bytes, thus requiring that av->top + be extended or replaced. +*/ +static void* __malloc_alloc(size_t nb, mstate av) +{ + mchunkptr old_top; /* incoming value of av->top */ + size_t old_size; /* its size */ + char* old_end; /* its end address */ + + long size; /* arg to first MORECORE or mmap call */ + char* brk; /* return value from MORECORE */ + + long correction; /* arg to 2nd MORECORE call */ + char* snd_brk; /* 2nd return val */ + + size_t front_misalign; /* unusable bytes at front of new space */ + size_t end_misalign; /* partial page left at end of new space */ + char* aligned_brk; /* aligned offset into brk */ + + mchunkptr p; /* the allocated/returned chunk */ + mchunkptr remainder; /* remainder from allocation */ + unsigned long remainder_size; /* its size */ + + unsigned long sum; /* for updating stats */ + + size_t pagemask = av->pagesize - 1; + + /* + If there is space available in fastbins, consolidate and retry + malloc from scratch rather than getting memory from system. This + can occur only if nb is in smallbin range so we didn't consolidate + upon entry to malloc. It is much easier to handle this case here + than in malloc proper. + */ + + if (have_fastchunks(av)) { + assert(in_smallbin_range(nb)); + __malloc_consolidate(av); + return malloc(nb - MALLOC_ALIGN_MASK); + } + + + /* + If have mmap, and the request size meets the mmap threshold, and + the system supports mmap, and there are few enough currently + allocated mmapped regions, try to directly map this request + rather than expanding top. + */ + + if ((unsigned long)(nb) >= (unsigned long)(av->mmap_threshold) && + (av->n_mmaps < av->n_mmaps_max)) { + + char* mm; /* return value from mmap call*/ + + /* + Round up size to nearest page. For mmapped chunks, the overhead + is one (sizeof(size_t)) unit larger than for normal chunks, because there + is no following chunk whose prev_size field could be used. + */ + size = (nb + (sizeof(size_t)) + MALLOC_ALIGN_MASK + pagemask) & ~pagemask; + + /* Don't try if size wraps around 0 */ + if ((unsigned long)(size) > (unsigned long)(nb)) { + + mm = (char*)(MMAP(0, size, PROT_READ|PROT_WRITE, MAP_PRIVATE)); + + if (mm != (char*)(MORECORE_FAILURE)) { + + /* + The offset to the start of the mmapped region is stored + in the prev_size field of the chunk. This allows us to adjust + returned start address to meet alignment requirements here + and in memalign(), and still be able to compute proper + address argument for later munmap in free() and realloc(). + */ + + front_misalign = (size_t)chunk2mem(mm) & MALLOC_ALIGN_MASK; + if (front_misalign > 0) { + correction = MALLOC_ALIGNMENT - front_misalign; + p = (mchunkptr)(mm + correction); + p->prev_size = correction; + set_head(p, (size - correction) |IS_MMAPPED); + } + else { + p = (mchunkptr)mm; + p->prev_size = 0; + set_head(p, size|IS_MMAPPED); + } + + /* update statistics */ + + if (++av->n_mmaps > av->max_n_mmaps) + av->max_n_mmaps = av->n_mmaps; + + sum = av->mmapped_mem += size; + if (sum > (unsigned long)(av->max_mmapped_mem)) + av->max_mmapped_mem = sum; + sum += av->sbrked_mem; + if (sum > (unsigned long)(av->max_total_mem)) + av->max_total_mem = sum; + + check_chunk(p); + + return chunk2mem(p); + } + } + } + + /* Record incoming configuration of top */ + + old_top = av->top; + old_size = chunksize(old_top); + old_end = (char*)(chunk_at_offset(old_top, old_size)); + + brk = snd_brk = (char*)(MORECORE_FAILURE); + + /* If not the first time through, we require old_size to + * be at least MINSIZE and to have prev_inuse set. */ + + assert((old_top == initial_top(av) && old_size == 0) || + ((unsigned long) (old_size) >= MINSIZE && + prev_inuse(old_top))); + + /* Precondition: not enough current space to satisfy nb request */ + assert((unsigned long)(old_size) < (unsigned long)(nb + MINSIZE)); + + /* Precondition: all fastbins are consolidated */ + assert(!have_fastchunks(av)); + + + /* Request enough space for nb + pad + overhead */ + + size = nb + av->top_pad + MINSIZE; + + /* + If contiguous, we can subtract out existing space that we hope to + combine with new space. We add it back later only if + we don't actually get contiguous space. + */ + + if (contiguous(av)) + size -= old_size; + + /* + Round to a multiple of page size. + If MORECORE is not contiguous, this ensures that we only call it + with whole-page arguments. And if MORECORE is contiguous and + this is not first time through, this preserves page-alignment of + previous calls. Otherwise, we correct to page-align below. + */ + + size = (size + pagemask) & ~pagemask; + + /* + Don't try to call MORECORE if argument is so big as to appear + negative. Note that since mmap takes size_t arg, it may succeed + below even if we cannot call MORECORE. + */ + + if (size > 0) + brk = (char*)(MORECORE(size)); + + /* + If have mmap, try using it as a backup when MORECORE fails or + cannot be used. This is worth doing on systems that have "holes" in + address space, so sbrk cannot extend to give contiguous space, but + space is available elsewhere. Note that we ignore mmap max count + and threshold limits, since the space will not be used as a + segregated mmap region. + */ + + if (brk == (char*)(MORECORE_FAILURE)) { + + /* Cannot merge with old top, so add its size back in */ + if (contiguous(av)) + size = (size + old_size + pagemask) & ~pagemask; + + /* If we are relying on mmap as backup, then use larger units */ + if ((unsigned long)(size) < (unsigned long)(MMAP_AS_MORECORE_SIZE)) + size = MMAP_AS_MORECORE_SIZE; + + /* Don't try if size wraps around 0 */ + if ((unsigned long)(size) > (unsigned long)(nb)) { + + brk = (char*)(MMAP(0, size, PROT_READ|PROT_WRITE, MAP_PRIVATE)); + + if (brk != (char*)(MORECORE_FAILURE)) { + + /* We do not need, and cannot use, another sbrk call to find end */ + snd_brk = brk + size; + + /* Record that we no longer have a contiguous sbrk region. + After the first time mmap is used as backup, we do not + ever rely on contiguous space since this could incorrectly + bridge regions. + */ + set_noncontiguous(av); + } + } + } + + if (brk != (char*)(MORECORE_FAILURE)) { + av->sbrked_mem += size; + + /* + If MORECORE extends previous space, we can likewise extend top size. + */ + + if (brk == old_end && snd_brk == (char*)(MORECORE_FAILURE)) { + set_head(old_top, (size + old_size) | PREV_INUSE); + } + + /* + Otherwise, make adjustments: + + * If the first time through or noncontiguous, we need to call sbrk + just to find out where the end of memory lies. + + * We need to ensure that all returned chunks from malloc will meet + MALLOC_ALIGNMENT + + * If there was an intervening foreign sbrk, we need to adjust sbrk + request size to account for fact that we will not be able to + combine new space with existing space in old_top. + + * Almost all systems internally allocate whole pages at a time, in + which case we might as well use the whole last page of request. + So we allocate enough more memory to hit a page boundary now, + which in turn causes future contiguous calls to page-align. + */ + + else { + front_misalign = 0; + end_misalign = 0; + correction = 0; + aligned_brk = brk; + + /* + If MORECORE returns an address lower than we have seen before, + we know it isn't really contiguous. This and some subsequent + checks help cope with non-conforming MORECORE functions and + the presence of "foreign" calls to MORECORE from outside of + malloc or by other threads. We cannot guarantee to detect + these in all cases, but cope with the ones we do detect. + */ + if (contiguous(av) && old_size != 0 && brk < old_end) { + set_noncontiguous(av); + } + + /* handle contiguous cases */ + if (contiguous(av)) { + + /* We can tolerate forward non-contiguities here (usually due + to foreign calls) but treat them as part of our space for + stats reporting. */ + if (old_size != 0) + av->sbrked_mem += brk - old_end; + + /* Guarantee alignment of first new chunk made from this space */ + + front_misalign = (size_t)chunk2mem(brk) & MALLOC_ALIGN_MASK; + if (front_misalign > 0) { + + /* + Skip over some bytes to arrive at an aligned position. + We don't need to specially mark these wasted front bytes. + They will never be accessed anyway because + prev_inuse of av->top (and any chunk created from its start) + is always true after initialization. + */ + + correction = MALLOC_ALIGNMENT - front_misalign; + aligned_brk += correction; + } + + /* + If this isn't adjacent to existing space, then we will not + be able to merge with old_top space, so must add to 2nd request. + */ + + correction += old_size; + + /* Extend the end address to hit a page boundary */ + end_misalign = (size_t)(brk + size + correction); + correction += ((end_misalign + pagemask) & ~pagemask) - end_misalign; + + assert(correction >= 0); + snd_brk = (char*)(MORECORE(correction)); + + if (snd_brk == (char*)(MORECORE_FAILURE)) { + /* + If can't allocate correction, try to at least find out current + brk. It might be enough to proceed without failing. + */ + correction = 0; + snd_brk = (char*)(MORECORE(0)); + } + else if (snd_brk < brk) { + /* + If the second call gives noncontiguous space even though + it says it won't, the only course of action is to ignore + results of second call, and conservatively estimate where + the first call left us. Also set noncontiguous, so this + won't happen again, leaving at most one hole. + + Note that this check is intrinsically incomplete. Because + MORECORE is allowed to give more space than we ask for, + there is no reliable way to detect a noncontiguity + producing a forward gap for the second call. + */ + snd_brk = brk + size; + correction = 0; + set_noncontiguous(av); + } + + } + + /* handle non-contiguous cases */ + else { + /* MORECORE/mmap must correctly align */ + assert(aligned_OK(chunk2mem(brk))); + + /* Find out current end of memory */ + if (snd_brk == (char*)(MORECORE_FAILURE)) { + snd_brk = (char*)(MORECORE(0)); + av->sbrked_mem += snd_brk - brk - size; + } + } + + /* Adjust top based on results of second sbrk */ + if (snd_brk != (char*)(MORECORE_FAILURE)) { + av->top = (mchunkptr)aligned_brk; + set_head(av->top, (snd_brk - aligned_brk + correction) | PREV_INUSE); + av->sbrked_mem += correction; + + /* + If not the first time through, we either have a + gap due to foreign sbrk or a non-contiguous region. Insert a + double fencepost at old_top to prevent consolidation with space + we don't own. These fenceposts are artificial chunks that are + marked as inuse and are in any case too small to use. We need + two to make sizes and alignments work out. + */ + + if (old_size != 0) { + /* Shrink old_top to insert fenceposts, keeping size a + multiple of MALLOC_ALIGNMENT. We know there is at least + enough space in old_top to do this. + */ + old_size = (old_size - 3*(sizeof(size_t))) & ~MALLOC_ALIGN_MASK; + set_head(old_top, old_size | PREV_INUSE); + + /* + Note that the following assignments completely overwrite + old_top when old_size was previously MINSIZE. This is + intentional. We need the fencepost, even if old_top otherwise gets + lost. + */ + chunk_at_offset(old_top, old_size )->size = + (sizeof(size_t))|PREV_INUSE; + + chunk_at_offset(old_top, old_size + (sizeof(size_t)))->size = + (sizeof(size_t))|PREV_INUSE; + + /* If possible, release the rest, suppressing trimming. */ + if (old_size >= MINSIZE) { + size_t tt = av->trim_threshold; + av->trim_threshold = (size_t)(-1); + free(chunk2mem(old_top)); + av->trim_threshold = tt; + } + } + } + } + + /* Update statistics */ + sum = av->sbrked_mem; + if (sum > (unsigned long)(av->max_sbrked_mem)) + av->max_sbrked_mem = sum; + + sum += av->mmapped_mem; + if (sum > (unsigned long)(av->max_total_mem)) + av->max_total_mem = sum; + + check_malloc_state(); + + /* finally, do the allocation */ + + p = av->top; + size = chunksize(p); + + /* check that one of the above allocation paths succeeded */ + if ((unsigned long)(size) >= (unsigned long)(nb + MINSIZE)) { + remainder_size = size - nb; + remainder = chunk_at_offset(p, nb); + av->top = remainder; + set_head(p, nb | PREV_INUSE); + set_head(remainder, remainder_size | PREV_INUSE); + check_malloced_chunk(p, nb); + return chunk2mem(p); + } + + } + + /* catch all failure paths */ + errno = ENOMEM; + return 0; +} + + +/* + Compute index for size. We expect this to be inlined when + compiled with optimization, else not, which works out well. +*/ +static int __malloc_largebin_index(unsigned int sz) +{ + unsigned int x = sz >> SMALLBIN_WIDTH; + unsigned int m; /* bit position of highest set bit of m */ + + if (x >= 0x10000) return NBINS-1; + + /* On intel, use BSRL instruction to find highest bit */ +#if defined(__GNUC__) && defined(i386) + + __asm__("bsrl %1,%0\n\t" + : "=r" (m) + : "g" (x)); + +#else + { + /* + Based on branch-free nlz algorithm in chapter 5 of Henry + S. Warren Jr's book "Hacker's Delight". + */ + + unsigned int n = ((x - 0x100) >> 16) & 8; + x <<= n; + m = ((x - 0x1000) >> 16) & 4; + n += m; + x <<= m; + m = ((x - 0x4000) >> 16) & 2; + n += m; + x = (x << m) >> 14; + m = 13 - n + (x & ~(x>>1)); + } +#endif + + /* Use next 2 bits to create finer-granularity bins */ + return NSMALLBINS + (m << 2) + ((sz >> (m + 6)) & 3); +} + + + +/* ---------------------------------------------------------------------- + * + * PUBLIC STUFF + * + * ----------------------------------------------------------------------*/ + + +/* ------------------------------ malloc ------------------------------ */ +void* malloc(size_t bytes) +{ + mstate av; + + size_t nb; /* normalized request size */ + unsigned int idx; /* associated bin index */ + mbinptr bin; /* associated bin */ + mfastbinptr* fb; /* associated fastbin */ + + mchunkptr victim; /* inspected/selected chunk */ + size_t size; /* its size */ + int victim_index; /* its bin index */ + + mchunkptr remainder; /* remainder from a split */ + unsigned long remainder_size; /* its size */ + + unsigned int block; /* bit map traverser */ + unsigned int bit; /* bit map traverser */ + unsigned int map; /* current word of binmap */ + + mchunkptr fwd; /* misc temp for linking */ + mchunkptr bck; /* misc temp for linking */ + void * sysmem; + + LOCK; + av = get_malloc_state(); + /* + Convert request size to internal form by adding (sizeof(size_t)) bytes + overhead plus possibly more to obtain necessary alignment and/or + to obtain a size of at least MINSIZE, the smallest allocatable + size. Also, checked_request2size traps (returning 0) request sizes + that are so large that they wrap around zero when padded and + aligned. + */ + + checked_request2size(bytes, nb); + + /* + Bypass search if no frees yet + */ + if (!have_anychunks(av)) { + if (av->max_fast == 0) /* initialization check */ + __malloc_consolidate(av); + goto use_top; + } + + /* + If the size qualifies as a fastbin, first check corresponding bin. + */ + + if ((unsigned long)(nb) <= (unsigned long)(av->max_fast)) { + fb = &(av->fastbins[(fastbin_index(nb))]); + if ( (victim = *fb) != 0) { + *fb = victim->fd; + check_remalloced_chunk(victim, nb); + UNLOCK; + return chunk2mem(victim); + } + } + + /* + If a small request, check regular bin. Since these "smallbins" + hold one size each, no searching within bins is necessary. + (For a large request, we need to wait until unsorted chunks are + processed to find best fit. But for small ones, fits are exact + anyway, so we can check now, which is faster.) + */ + + if (in_smallbin_range(nb)) { + idx = smallbin_index(nb); + bin = bin_at(av,idx); + + if ( (victim = last(bin)) != bin) { + bck = victim->bk; + set_inuse_bit_at_offset(victim, nb); + bin->bk = bck; + bck->fd = bin; + + check_malloced_chunk(victim, nb); + UNLOCK; + return chunk2mem(victim); + } + } + + /* If this is a large request, consolidate fastbins before continuing. + While it might look excessive to kill all fastbins before + even seeing if there is space available, this avoids + fragmentation problems normally associated with fastbins. + Also, in practice, programs tend to have runs of either small or + large requests, but less often mixtures, so consolidation is not + invoked all that often in most programs. And the programs that + it is called frequently in otherwise tend to fragment. + */ + + else { + idx = __malloc_largebin_index(nb); + if (have_fastchunks(av)) + __malloc_consolidate(av); + } + + /* + Process recently freed or remaindered chunks, taking one only if + it is exact fit, or, if this a small request, the chunk is remainder from + the most recent non-exact fit. Place other traversed chunks in + bins. Note that this step is the only place in any routine where + chunks are placed in bins. + */ + + while ( (victim = unsorted_chunks(av)->bk) != unsorted_chunks(av)) { + bck = victim->bk; + size = chunksize(victim); + + /* If a small request, try to use last remainder if it is the + only chunk in unsorted bin. This helps promote locality for + runs of consecutive small requests. This is the only + exception to best-fit, and applies only when there is + no exact fit for a small chunk. + */ + + if (in_smallbin_range(nb) && + bck == unsorted_chunks(av) && + victim == av->last_remainder && + (unsigned long)(size) > (unsigned long)(nb + MINSIZE)) { + + /* split and reattach remainder */ + remainder_size = size - nb; + remainder = chunk_at_offset(victim, nb); + unsorted_chunks(av)->bk = unsorted_chunks(av)->fd = remainder; + av->last_remainder = remainder; + remainder->bk = remainder->fd = unsorted_chunks(av); + + set_head(victim, nb | PREV_INUSE); + set_head(remainder, remainder_size | PREV_INUSE); + set_foot(remainder, remainder_size); + + check_malloced_chunk(victim, nb); + UNLOCK; + return chunk2mem(victim); + } + + /* remove from unsorted list */ + unsorted_chunks(av)->bk = bck; + bck->fd = unsorted_chunks(av); + + /* Take now instead of binning if exact fit */ + + if (size == nb) { + set_inuse_bit_at_offset(victim, size); + check_malloced_chunk(victim, nb); + UNLOCK; + return chunk2mem(victim); + } + + /* place chunk in bin */ + + if (in_smallbin_range(size)) { + victim_index = smallbin_index(size); + bck = bin_at(av, victim_index); + fwd = bck->fd; + } + else { + victim_index = __malloc_largebin_index(size); + bck = bin_at(av, victim_index); + fwd = bck->fd; + + if (fwd != bck) { + /* if smaller than smallest, place first */ + if ((unsigned long)(size) < (unsigned long)(bck->bk->size)) { + fwd = bck; + bck = bck->bk; + } + else if ((unsigned long)(size) >= + (unsigned long)(FIRST_SORTED_BIN_SIZE)) { + + /* maintain large bins in sorted order */ + size |= PREV_INUSE; /* Or with inuse bit to speed comparisons */ + while ((unsigned long)(size) < (unsigned long)(fwd->size)) + fwd = fwd->fd; + bck = fwd->bk; + } + } + } + + mark_bin(av, victim_index); + victim->bk = bck; + victim->fd = fwd; + fwd->bk = victim; + bck->fd = victim; + } + + /* + If a large request, scan through the chunks of current bin to + find one that fits. (This will be the smallest that fits unless + FIRST_SORTED_BIN_SIZE has been changed from default.) This is + the only step where an unbounded number of chunks might be + scanned without doing anything useful with them. However the + lists tend to be short. + */ + + if (!in_smallbin_range(nb)) { + bin = bin_at(av, idx); + + for (victim = last(bin); victim != bin; victim = victim->bk) { + size = chunksize(victim); + + if ((unsigned long)(size) >= (unsigned long)(nb)) { + remainder_size = size - nb; + unlink(victim, bck, fwd); + + /* Exhaust */ + if (remainder_size < MINSIZE) { + set_inuse_bit_at_offset(victim, size); + check_malloced_chunk(victim, nb); + UNLOCK; + return chunk2mem(victim); + } + /* Split */ + else { + remainder = chunk_at_offset(victim, nb); + unsorted_chunks(av)->bk = unsorted_chunks(av)->fd = remainder; + remainder->bk = remainder->fd = unsorted_chunks(av); + set_head(victim, nb | PREV_INUSE); + set_head(remainder, remainder_size | PREV_INUSE); + set_foot(remainder, remainder_size); + check_malloced_chunk(victim, nb); + UNLOCK; + return chunk2mem(victim); + } + } + } + } + + /* + Search for a chunk by scanning bins, starting with next largest + bin. This search is strictly by best-fit; i.e., the smallest + (with ties going to approximately the least recently used) chunk + that fits is selected. + + The bitmap avoids needing to check that most blocks are nonempty. + */ + + ++idx; + bin = bin_at(av,idx); + block = idx2block(idx); + map = av->binmap[block]; + bit = idx2bit(idx); + + for (;;) { + + /* Skip rest of block if there are no more set bits in this block. */ + if (bit > map || bit == 0) { + do { + if (++block >= BINMAPSIZE) /* out of bins */ + goto use_top; + } while ( (map = av->binmap[block]) == 0); + + bin = bin_at(av, (block << BINMAPSHIFT)); + bit = 1; + } + + /* Advance to bin with set bit. There must be one. */ + while ((bit & map) == 0) { + bin = next_bin(bin); + bit <<= 1; + assert(bit != 0); + } + + /* Inspect the bin. It is likely to be non-empty */ + victim = last(bin); + + /* If a false alarm (empty bin), clear the bit. */ + if (victim == bin) { + av->binmap[block] = map &= ~bit; /* Write through */ + bin = next_bin(bin); + bit <<= 1; + } + + else { + size = chunksize(victim); + + /* We know the first chunk in this bin is big enough to use. */ + assert((unsigned long)(size) >= (unsigned long)(nb)); + + remainder_size = size - nb; + + /* unlink */ + bck = victim->bk; + bin->bk = bck; + bck->fd = bin; + + /* Exhaust */ + if (remainder_size < MINSIZE) { + set_inuse_bit_at_offset(victim, size); + check_malloced_chunk(victim, nb); + UNLOCK; + return chunk2mem(victim); + } + + /* Split */ + else { + remainder = chunk_at_offset(victim, nb); + + unsorted_chunks(av)->bk = unsorted_chunks(av)->fd = remainder; + remainder->bk = remainder->fd = unsorted_chunks(av); + /* advertise as last remainder */ + if (in_smallbin_range(nb)) + av->last_remainder = remainder; + + set_head(victim, nb | PREV_INUSE); + set_head(remainder, remainder_size | PREV_INUSE); + set_foot(remainder, remainder_size); + check_malloced_chunk(victim, nb); + UNLOCK; + return chunk2mem(victim); + } + } + } + +use_top: + /* + If large enough, split off the chunk bordering the end of memory + (held in av->top). Note that this is in accord with the best-fit + search rule. In effect, av->top is treated as larger (and thus + less well fitting) than any other available chunk since it can + be extended to be as large as necessary (up to system + limitations). + + We require that av->top always exists (i.e., has size >= + MINSIZE) after initialization, so if it would otherwise be + exhuasted by current request, it is replenished. (The main + reason for ensuring it exists is that we may need MINSIZE space + to put in fenceposts in sysmalloc.) + */ + + victim = av->top; + size = chunksize(victim); + + if ((unsigned long)(size) >= (unsigned long)(nb + MINSIZE)) { + remainder_size = size - nb; + remainder = chunk_at_offset(victim, nb); + av->top = remainder; + set_head(victim, nb | PREV_INUSE); + set_head(remainder, remainder_size | PREV_INUSE); + + check_malloced_chunk(victim, nb); + UNLOCK; + return chunk2mem(victim); + } + + /* If no space in top, relay to handle system-dependent cases */ + sysmem = __malloc_alloc(nb, av); + UNLOCK; + return sysmem; +} + diff --git a/libc/stdlib/malloc-standard/malloc.h b/libc/stdlib/malloc-standard/malloc.h new file mode 100644 index 000000000..46858332d --- /dev/null +++ b/libc/stdlib/malloc-standard/malloc.h @@ -0,0 +1,953 @@ +/* + This is a version (aka dlmalloc) of malloc/free/realloc written by + Doug Lea and released to the public domain. Use, modify, and + redistribute this code without permission or acknowledgement in any + way you wish. Send questions, comments, complaints, performance + data, etc to dl@cs.oswego.edu + + VERSION 2.7.2 Sat Aug 17 09:07:30 2002 Doug Lea (dl at gee) + + Note: There may be an updated version of this malloc obtainable at + ftp://gee.cs.oswego.edu/pub/misc/malloc.c + Check before installing! + + Hacked up for uClibc by Erik Andersen <andersen@codepoet.org> +*/ + +#include <features.h> +#include <stddef.h> +#include <unistd.h> +#include <errno.h> +#include <string.h> +#include <malloc.h> + + +#ifdef __UCLIBC_HAS_THREADS__ +#include <pthread.h> +extern pthread_mutex_t __malloc_lock; +# define LOCK __pthread_mutex_lock(&__malloc_lock) +# define UNLOCK __pthread_mutex_unlock(&__malloc_lock); +#else +# define LOCK +# define UNLOCK +#endif + + + +/* + MALLOC_ALIGNMENT is the minimum alignment for malloc'ed chunks. + It must be a power of two at least 2 * (sizeof(size_t)), even on machines + for which smaller alignments would suffice. It may be defined as + larger than this though. Note however that code and data structures + are optimized for the case of 8-byte alignment. +*/ +#ifndef MALLOC_ALIGNMENT +#define MALLOC_ALIGNMENT (2 * (sizeof(size_t))) +#endif + +/* The corresponding bit mask value */ +#define MALLOC_ALIGN_MASK (MALLOC_ALIGNMENT - 1) + +/* + TRIM_FASTBINS controls whether free() of a very small chunk can + immediately lead to trimming. Setting to true (1) can reduce memory + footprint, but will almost always slow down programs that use a lot + of small chunks. + + Define this only if you are willing to give up some speed to more + aggressively reduce system-level memory footprint when releasing + memory in programs that use many small chunks. You can get + essentially the same effect by setting MXFAST to 0, but this can + lead to even greater slowdowns in programs using many small chunks. + TRIM_FASTBINS is an in-between compile-time option, that disables + only those chunks bordering topmost memory from being placed in + fastbins. +*/ +#ifndef TRIM_FASTBINS +#define TRIM_FASTBINS 0 +#endif + + +/* + MORECORE-related declarations. By default, rely on sbrk +*/ + + +/* + MORECORE is the name of the routine to call to obtain more memory + from the system. See below for general guidance on writing + alternative MORECORE functions, as well as a version for WIN32 and a + sample version for pre-OSX macos. +*/ +#ifndef MORECORE +#define MORECORE sbrk +#endif + +/* + MORECORE_FAILURE is the value returned upon failure of MORECORE + as well as mmap. Since it cannot be an otherwise valid memory address, + and must reflect values of standard sys calls, you probably ought not + try to redefine it. +*/ +#ifndef MORECORE_FAILURE +#define MORECORE_FAILURE (-1) +#endif + +/* + If MORECORE_CONTIGUOUS is true, take advantage of fact that + consecutive calls to MORECORE with positive arguments always return + contiguous increasing addresses. This is true of unix sbrk. Even + if not defined, when regions happen to be contiguous, malloc will + permit allocations spanning regions obtained from different + calls. But defining this when applicable enables some stronger + consistency checks and space efficiencies. +*/ +#ifndef MORECORE_CONTIGUOUS +#define MORECORE_CONTIGUOUS 1 +#endif + +/* + MMAP_AS_MORECORE_SIZE is the minimum mmap size argument to use if + sbrk fails, and mmap is used as a backup (which is done only if + HAVE_MMAP). The value must be a multiple of page size. This + backup strategy generally applies only when systems have "holes" in + address space, so sbrk cannot perform contiguous expansion, but + there is still space available on system. On systems for which + this is known to be useful (i.e. most linux kernels), this occurs + only when programs allocate huge amounts of memory. Between this, + and the fact that mmap regions tend to be limited, the size should + be large, to avoid too many mmap calls and thus avoid running out + of kernel resources. +*/ +#ifndef MMAP_AS_MORECORE_SIZE +#define MMAP_AS_MORECORE_SIZE (1024 * 1024) +#endif + +/* + The system page size. To the extent possible, this malloc manages + memory from the system in page-size units. Note that this value is + cached during initialization into a field of malloc_state. So even + if malloc_getpagesize is a function, it is only called once. + + The following mechanics for getpagesize were adapted from bsd/gnu + getpagesize.h. If none of the system-probes here apply, a value of + 4096 is used, which should be OK: If they don't apply, then using + the actual value probably doesn't impact performance. +*/ +#ifndef malloc_getpagesize +# include <unistd.h> +# define malloc_getpagesize sysconf(_SC_PAGE_SIZE) +#else /* just guess */ +# define malloc_getpagesize (4096) +#endif + + +/* mallopt tuning options */ + +/* + M_MXFAST is the maximum request size used for "fastbins", special bins + that hold returned chunks without consolidating their spaces. This + enables future requests for chunks of the same size to be handled + very quickly, but can increase fragmentation, and thus increase the + overall memory footprint of a program. + + This malloc manages fastbins very conservatively yet still + efficiently, so fragmentation is rarely a problem for values less + than or equal to the default. The maximum supported value of MXFAST + is 80. You wouldn't want it any higher than this anyway. Fastbins + are designed especially for use with many small structs, objects or + strings -- the default handles structs/objects/arrays with sizes up + to 16 4byte fields, or small strings representing words, tokens, + etc. Using fastbins for larger objects normally worsens + fragmentation without improving speed. + + M_MXFAST is set in REQUEST size units. It is internally used in + chunksize units, which adds padding and alignment. You can reduce + M_MXFAST to 0 to disable all use of fastbins. This causes the malloc + algorithm to be a closer approximation of fifo-best-fit in all cases, + not just for larger requests, but will generally cause it to be + slower. +*/ + + +/* M_MXFAST is a standard SVID/XPG tuning option, usually listed in malloc.h */ +#ifndef M_MXFAST +#define M_MXFAST 1 +#endif + +#ifndef DEFAULT_MXFAST +#define DEFAULT_MXFAST 64 +#endif + + +/* + M_TRIM_THRESHOLD is the maximum amount of unused top-most memory + to keep before releasing via malloc_trim in free(). + + Automatic trimming is mainly useful in long-lived programs. + Because trimming via sbrk can be slow on some systems, and can + sometimes be wasteful (in cases where programs immediately + afterward allocate more large chunks) the value should be high + enough so that your overall system performance would improve by + releasing this much memory. + + The trim threshold and the mmap control parameters (see below) + can be traded off with one another. Trimming and mmapping are + two different ways of releasing unused memory back to the + system. Between these two, it is often possible to keep + system-level demands of a long-lived program down to a bare + minimum. For example, in one test suite of sessions measuring + the XF86 X server on Linux, using a trim threshold of 128K and a + mmap threshold of 192K led to near-minimal long term resource + consumption. + + If you are using this malloc in a long-lived program, it should + pay to experiment with these values. As a rough guide, you + might set to a value close to the average size of a process + (program) running on your system. Releasing this much memory + would allow such a process to run in memory. Generally, it's + worth it to tune for trimming rather tham memory mapping when a + program undergoes phases where several large chunks are + allocated and released in ways that can reuse each other's + storage, perhaps mixed with phases where there are no such + chunks at all. And in well-behaved long-lived programs, + controlling release of large blocks via trimming versus mapping + is usually faster. + + However, in most programs, these parameters serve mainly as + protection against the system-level effects of carrying around + massive amounts of unneeded memory. Since frequent calls to + sbrk, mmap, and munmap otherwise degrade performance, the default + parameters are set to relatively high values that serve only as + safeguards. + + The trim value must be greater than page size to have any useful + effect. To disable trimming completely, you can set to + (unsigned long)(-1) + + Trim settings interact with fastbin (MXFAST) settings: Unless + TRIM_FASTBINS is defined, automatic trimming never takes place upon + freeing a chunk with size less than or equal to MXFAST. Trimming is + instead delayed until subsequent freeing of larger chunks. However, + you can still force an attempted trim by calling malloc_trim. + + Also, trimming is not generally possible in cases where + the main arena is obtained via mmap. + + Note that the trick some people use of mallocing a huge space and + then freeing it at program startup, in an attempt to reserve system + memory, doesn't have the intended effect under automatic trimming, + since that memory will immediately be returned to the system. +*/ +#define M_TRIM_THRESHOLD -1 + +#ifndef DEFAULT_TRIM_THRESHOLD +#define DEFAULT_TRIM_THRESHOLD (256 * 1024) +#endif + +/* + M_TOP_PAD is the amount of extra `padding' space to allocate or + retain whenever sbrk is called. It is used in two ways internally: + + * When sbrk is called to extend the top of the arena to satisfy + a new malloc request, this much padding is added to the sbrk + request. + + * When malloc_trim is called automatically from free(), + it is used as the `pad' argument. + + In both cases, the actual amount of padding is rounded + so that the end of the arena is always a system page boundary. + + The main reason for using padding is to avoid calling sbrk so + often. Having even a small pad greatly reduces the likelihood + that nearly every malloc request during program start-up (or + after trimming) will invoke sbrk, which needlessly wastes + time. + + Automatic rounding-up to page-size units is normally sufficient + to avoid measurable overhead, so the default is 0. However, in + systems where sbrk is relatively slow, it can pay to increase + this value, at the expense of carrying around more memory than + the program needs. +*/ +#define M_TOP_PAD -2 + +#ifndef DEFAULT_TOP_PAD +#define DEFAULT_TOP_PAD (0) +#endif + +/* + M_MMAP_THRESHOLD is the request size threshold for using mmap() + to service a request. Requests of at least this size that cannot + be allocated using already-existing space will be serviced via mmap. + (If enough normal freed space already exists it is used instead.) + + Using mmap segregates relatively large chunks of memory so that + they can be individually obtained and released from the host + system. A request serviced through mmap is never reused by any + other request (at least not directly; the system may just so + happen to remap successive requests to the same locations). + + Segregating space in this way has the benefits that: + + 1. 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. + 2. Mapped memory can never become `locked' between + other chunks, as can happen with normally allocated chunks, which + means that even trimming via malloc_trim would not release them. + 3. On some systems with "holes" in address spaces, mmap can obtain + memory that sbrk cannot. + + 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. + + The advantages of mmap nearly always outweigh disadvantages for + "large" chunks, but the value of "large" varies across systems. The + default is an empirically derived value that works well in most + systems. +*/ +#define M_MMAP_THRESHOLD -3 + +#ifndef DEFAULT_MMAP_THRESHOLD +#define DEFAULT_MMAP_THRESHOLD (256 * 1024) +#endif + +/* + M_MMAP_MAX is the maximum number of requests to simultaneously + service using mmap. This parameter exists because +. Some systems have a limited number of internal tables for + use by mmap, and using more than a few of them may degrade + performance. + + The default is set to a value that serves only as a safeguard. + Setting to 0 disables use of mmap for servicing large requests. If + HAVE_MMAP is not set, the default value is 0, and attempts to set it + to non-zero values in mallopt will fail. +*/ +#define M_MMAP_MAX -4 + +#ifndef DEFAULT_MMAP_MAX +#define DEFAULT_MMAP_MAX (65536) +#endif + + +/* ------------------ MMAP support ------------------ */ +#include <fcntl.h> +#include <sys/mman.h> + +#if !defined(MAP_ANONYMOUS) && defined(MAP_ANON) +#define MAP_ANONYMOUS MAP_ANON +#endif + +#define MMAP(addr, size, prot, flags) \ + (mmap((addr), (size), (prot), (flags)|MAP_ANONYMOUS, -1, 0)) + + +/* ----------------------- Chunk representations ----------------------- */ + + +/* + This struct declaration is misleading (but accurate and necessary). + It declares a "view" into memory allowing access to necessary + fields at known offsets from a given base. See explanation below. +*/ + +struct malloc_chunk { + + size_t prev_size; /* Size of previous chunk (if free). */ + size_t size; /* Size in bytes, including overhead. */ + + struct malloc_chunk* fd; /* double links -- used only if free. */ + struct malloc_chunk* bk; +}; + + +typedef struct malloc_chunk* mchunkptr; + +/* + malloc_chunk details: + + (The following includes lightly edited explanations by Colin Plumb.) + + Chunks of memory are maintained using a `boundary tag' method as + described in e.g., Knuth or Standish. (See the paper by Paul + Wilson ftp://ftp.cs.utexas.edu/pub/garbage/allocsrv.ps for a + survey of such techniques.) Sizes of free chunks are stored both + in the front of each chunk and at the end. This makes + consolidating fragmented chunks into bigger chunks very fast. The + size fields also hold bits representing whether chunks are free or + in use. + + An allocated chunk looks like this: + + + chunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Size of previous chunk, if allocated | | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Size of chunk, in bytes |P| + mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | User data starts here... . + . . + . (malloc_usable_space() bytes) . + . | +nextchunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Size of chunk | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + + + Where "chunk" is the front of the chunk for the purpose of most of + the malloc code, but "mem" is the pointer that is returned to the + user. "Nextchunk" is the beginning of the next contiguous chunk. + + Chunks always begin on even word boundries, so the mem portion + (which is returned to the user) is also on an even word boundary, and + thus at least double-word aligned. + + Free chunks are stored in circular doubly-linked lists, and look like this: + + chunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Size of previous chunk | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + `head:' | Size of chunk, in bytes |P| + mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Forward pointer to next chunk in list | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Back pointer to previous chunk in list | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Unused space (may be 0 bytes long) . + . . + . | +nextchunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + `foot:' | Size of chunk, in bytes | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + + The P (PREV_INUSE) bit, stored in the unused low-order bit of the + chunk size (which is always a multiple of two words), is an in-use + bit for the *previous* chunk. If that bit is *clear*, then the + word before the current chunk size contains the previous chunk + size, and can be used to find the front of the previous chunk. + The very first chunk allocated always has this bit set, + preventing access to non-existent (or non-owned) memory. If + prev_inuse is set for any given chunk, then you CANNOT determine + the size of the previous chunk, and might even get a memory + addressing fault when trying to do so. + + Note that the `foot' of the current chunk is actually represented + as the prev_size of the NEXT chunk. This makes it easier to + deal with alignments etc but can be very confusing when trying + to extend or adapt this code. + + The two exceptions to all this are + + 1. The special chunk `top' doesn't bother using the + trailing size field since there is no next contiguous chunk + that would have to index off it. After initialization, `top' + is forced to always exist. If it would become less than + MINSIZE bytes long, it is replenished. + + 2. Chunks allocated via mmap, which have the second-lowest-order + bit (IS_MMAPPED) set in their size fields. Because they are + allocated one-by-one, each must contain its own trailing size field. + +*/ + +/* + ---------- Size and alignment checks and conversions ---------- +*/ + +/* conversion from malloc headers to user pointers, and back */ + +#define chunk2mem(p) ((void*)((char*)(p) + 2*(sizeof(size_t)))) +#define mem2chunk(mem) ((mchunkptr)((char*)(mem) - 2*(sizeof(size_t)))) + +/* The smallest possible chunk */ +#define MIN_CHUNK_SIZE (sizeof(struct malloc_chunk)) + +/* The smallest size we can malloc is an aligned minimal chunk */ + +#define MINSIZE \ + (unsigned long)(((MIN_CHUNK_SIZE+MALLOC_ALIGN_MASK) & ~MALLOC_ALIGN_MASK)) + +/* Check if m has acceptable alignment */ + +#define aligned_OK(m) (((unsigned long)((m)) & (MALLOC_ALIGN_MASK)) == 0) + + +/* Check if a request is so large that it would wrap around zero when + padded and aligned. To simplify some other code, the bound is made + low enough so that adding MINSIZE will also not wrap around sero. +*/ + +#define REQUEST_OUT_OF_RANGE(req) \ + ((unsigned long)(req) >= \ + (unsigned long)(size_t)(-2 * MINSIZE)) + +/* pad request bytes into a usable size -- internal version */ + +#define request2size(req) \ + (((req) + (sizeof(size_t)) + MALLOC_ALIGN_MASK < MINSIZE) ? \ + MINSIZE : \ + ((req) + (sizeof(size_t)) + MALLOC_ALIGN_MASK) & ~MALLOC_ALIGN_MASK) + +/* Same, except also perform argument check */ + +#define checked_request2size(req, sz) \ + if (REQUEST_OUT_OF_RANGE(req)) { \ + errno = ENOMEM; \ + return 0; \ + } \ + (sz) = request2size(req); + +/* + --------------- Physical chunk operations --------------- +*/ + + +/* size field is or'ed with PREV_INUSE when previous adjacent chunk in use */ +#define PREV_INUSE 0x1 + +/* extract inuse bit of previous chunk */ +#define prev_inuse(p) ((p)->size & PREV_INUSE) + + +/* size field is or'ed with IS_MMAPPED if the chunk was obtained with mmap() */ +#define IS_MMAPPED 0x2 + +/* check for mmap()'ed chunk */ +#define chunk_is_mmapped(p) ((p)->size & IS_MMAPPED) + +/* Bits to mask off when extracting size + + Note: IS_MMAPPED is intentionally not masked off from size field in + macros for which mmapped chunks should never be seen. This should + cause helpful core dumps to occur if it is tried by accident by + people extending or adapting this malloc. +*/ +#define SIZE_BITS (PREV_INUSE|IS_MMAPPED) + +/* Get size, ignoring use bits */ +#define chunksize(p) ((p)->size & ~(SIZE_BITS)) + + +/* Ptr to next physical malloc_chunk. */ +#define next_chunk(p) ((mchunkptr)( ((char*)(p)) + ((p)->size & ~PREV_INUSE) )) + +/* Ptr to previous physical malloc_chunk */ +#define prev_chunk(p) ((mchunkptr)( ((char*)(p)) - ((p)->prev_size) )) + +/* Treat space at ptr + offset as a chunk */ +#define chunk_at_offset(p, s) ((mchunkptr)(((char*)(p)) + (s))) + +/* extract p's inuse bit */ +#define inuse(p)\ +((((mchunkptr)(((char*)(p))+((p)->size & ~PREV_INUSE)))->size) & PREV_INUSE) + +/* set/clear chunk as being inuse without otherwise disturbing */ +#define set_inuse(p)\ +((mchunkptr)(((char*)(p)) + ((p)->size & ~PREV_INUSE)))->size |= PREV_INUSE + +#define clear_inuse(p)\ +((mchunkptr)(((char*)(p)) + ((p)->size & ~PREV_INUSE)))->size &= ~(PREV_INUSE) + + +/* check/set/clear inuse bits in known places */ +#define inuse_bit_at_offset(p, s)\ + (((mchunkptr)(((char*)(p)) + (s)))->size & PREV_INUSE) + +#define set_inuse_bit_at_offset(p, s)\ + (((mchunkptr)(((char*)(p)) + (s)))->size |= PREV_INUSE) + +#define clear_inuse_bit_at_offset(p, s)\ + (((mchunkptr)(((char*)(p)) + (s)))->size &= ~(PREV_INUSE)) + + +/* Set size at head, without disturbing its use bit */ +#define set_head_size(p, s) ((p)->size = (((p)->size & PREV_INUSE) | (s))) + +/* Set size/use field */ +#define set_head(p, s) ((p)->size = (s)) + +/* Set size at footer (only when chunk is not in use) */ +#define set_foot(p, s) (((mchunkptr)((char*)(p) + (s)))->prev_size = (s)) + + +/* -------------------- Internal data structures -------------------- */ + +/* + Bins + + An array of bin headers for free chunks. Each bin is doubly + linked. The bins are approximately proportionally (log) spaced. + There are a lot of these bins (128). This may look excessive, but + works very well in practice. Most bins hold sizes that are + unusual as malloc request sizes, but are more usual for fragments + and consolidated sets of chunks, which is what these bins hold, so + they can be found quickly. All procedures maintain the invariant + that no consolidated chunk physically borders another one, so each + chunk in a list is known to be preceeded and followed by either + inuse chunks or the ends of memory. + + Chunks in bins are kept in size order, with ties going to the + approximately least recently used chunk. Ordering isn't needed + for the small bins, which all contain the same-sized chunks, but + facilitates best-fit allocation for larger chunks. These lists + are just sequential. Keeping them in order almost never requires + enough traversal to warrant using fancier ordered data + structures. + + Chunks of the same size are linked with the most + recently freed at the front, and allocations are taken from the + back. This results in LRU (FIFO) allocation order, which tends + to give each chunk an equal opportunity to be consolidated with + adjacent freed chunks, resulting in larger free chunks and less + fragmentation. + + To simplify use in double-linked lists, each bin header acts + as a malloc_chunk. This avoids special-casing for headers. + But to conserve space and improve locality, we allocate + only the fd/bk pointers of bins, and then use repositioning tricks + to treat these as the fields of a malloc_chunk*. +*/ + +typedef struct malloc_chunk* mbinptr; + +/* addressing -- note that bin_at(0) does not exist */ +#define bin_at(m, i) ((mbinptr)((char*)&((m)->bins[(i)<<1]) - ((sizeof(size_t))<<1))) + +/* analog of ++bin */ +#define next_bin(b) ((mbinptr)((char*)(b) + (sizeof(mchunkptr)<<1))) + +/* Reminders about list directionality within bins */ +#define first(b) ((b)->fd) +#define last(b) ((b)->bk) + +/* Take a chunk off a bin list */ +#define unlink(P, BK, FD) { \ + FD = P->fd; \ + BK = P->bk; \ + FD->bk = BK; \ + BK->fd = FD; \ +} + +/* + Indexing + + Bins for sizes < 512 bytes contain chunks of all the same size, spaced + 8 bytes apart. Larger bins are approximately logarithmically spaced: + + 64 bins of size 8 + 32 bins of size 64 + 16 bins of size 512 + 8 bins of size 4096 + 4 bins of size 32768 + 2 bins of size 262144 + 1 bin of size what's left + + The bins top out around 1MB because we expect to service large + requests via mmap. +*/ + +#define NBINS 96 +#define NSMALLBINS 32 +#define SMALLBIN_WIDTH 8 +#define MIN_LARGE_SIZE 256 + +#define in_smallbin_range(sz) \ + ((unsigned long)(sz) < (unsigned long)MIN_LARGE_SIZE) + +#define smallbin_index(sz) (((unsigned)(sz)) >> 3) + +#define bin_index(sz) \ + ((in_smallbin_range(sz)) ? smallbin_index(sz) : __malloc_largebin_index(sz)) + +/* + FIRST_SORTED_BIN_SIZE is the chunk size corresponding to the + first bin that is maintained in sorted order. This must + be the smallest size corresponding to a given bin. + + Normally, this should be MIN_LARGE_SIZE. But you can weaken + best fit guarantees to sometimes speed up malloc by increasing value. + Doing this means that malloc may choose a chunk that is + non-best-fitting by up to the width of the bin. + + Some useful cutoff values: + 512 - all bins sorted + 2560 - leaves bins <= 64 bytes wide unsorted + 12288 - leaves bins <= 512 bytes wide unsorted + 65536 - leaves bins <= 4096 bytes wide unsorted + 262144 - leaves bins <= 32768 bytes wide unsorted + -1 - no bins sorted (not recommended!) +*/ + +#define FIRST_SORTED_BIN_SIZE MIN_LARGE_SIZE +/* #define FIRST_SORTED_BIN_SIZE 65536 */ + +/* + Unsorted chunks + + All remainders from chunk splits, as well as all returned chunks, + are first placed in the "unsorted" bin. They are then placed + in regular bins after malloc gives them ONE chance to be used before + binning. So, basically, the unsorted_chunks list acts as a queue, + with chunks being placed on it in free (and __malloc_consolidate), + and taken off (to be either used or placed in bins) in malloc. +*/ + +/* The otherwise unindexable 1-bin is used to hold unsorted chunks. */ +#define unsorted_chunks(M) (bin_at(M, 1)) + +/* + Top + + The top-most available chunk (i.e., the one bordering the end of + available memory) is treated specially. It is never included in + any bin, is used only if no other chunk is available, and is + released back to the system if it is very large (see + M_TRIM_THRESHOLD). Because top initially + points to its own bin with initial zero size, thus forcing + extension on the first malloc request, we avoid having any special + code in malloc to check whether it even exists yet. But we still + need to do so when getting memory from system, so we make + initial_top treat the bin as a legal but unusable chunk during the + interval between initialization and the first call to + __malloc_alloc. (This is somewhat delicate, since it relies on + the 2 preceding words to be zero during this interval as well.) +*/ + +/* Conveniently, the unsorted bin can be used as dummy top on first call */ +#define initial_top(M) (unsorted_chunks(M)) + +/* + Binmap + + To help compensate for the large number of bins, a one-level index + structure is used for bin-by-bin searching. `binmap' is a + bitvector recording whether bins are definitely empty so they can + be skipped over during during traversals. The bits are NOT always + cleared as soon as bins are empty, but instead only + when they are noticed to be empty during traversal in malloc. +*/ + +/* Conservatively use 32 bits per map word, even if on 64bit system */ +#define BINMAPSHIFT 5 +#define BITSPERMAP (1U << BINMAPSHIFT) +#define BINMAPSIZE (NBINS / BITSPERMAP) + +#define idx2block(i) ((i) >> BINMAPSHIFT) +#define idx2bit(i) ((1U << ((i) & ((1U << BINMAPSHIFT)-1)))) + +#define mark_bin(m,i) ((m)->binmap[idx2block(i)] |= idx2bit(i)) +#define unmark_bin(m,i) ((m)->binmap[idx2block(i)] &= ~(idx2bit(i))) +#define get_binmap(m,i) ((m)->binmap[idx2block(i)] & idx2bit(i)) + +/* + Fastbins + + An array of lists holding recently freed small chunks. Fastbins + are not doubly linked. It is faster to single-link them, and + since chunks are never removed from the middles of these lists, + double linking is not necessary. Also, unlike regular bins, they + are not even processed in FIFO order (they use faster LIFO) since + ordering doesn't much matter in the transient contexts in which + fastbins are normally used. + + Chunks in fastbins keep their inuse bit set, so they cannot + be consolidated with other free chunks. __malloc_consolidate + releases all chunks in fastbins and consolidates them with + other free chunks. +*/ + +typedef struct malloc_chunk* mfastbinptr; + +/* offset 2 to use otherwise unindexable first 2 bins */ +#define fastbin_index(sz) ((((unsigned int)(sz)) >> 3) - 2) + +/* The maximum fastbin request size we support */ +#define MAX_FAST_SIZE 80 + +#define NFASTBINS (fastbin_index(request2size(MAX_FAST_SIZE))+1) + +/* + FASTBIN_CONSOLIDATION_THRESHOLD is the size of a chunk in free() + that triggers automatic consolidation of possibly-surrounding + fastbin chunks. This is a heuristic, so the exact value should not + matter too much. It is defined at half the default trim threshold as a + compromise heuristic to only attempt consolidation if it is likely + to lead to trimming. However, it is not dynamically tunable, since + consolidation reduces fragmentation surrounding loarge chunks even + if trimming is not used. +*/ + +#define FASTBIN_CONSOLIDATION_THRESHOLD \ + ((unsigned long)(DEFAULT_TRIM_THRESHOLD) >> 1) + +/* + Since the lowest 2 bits in max_fast don't matter in size comparisons, + they are used as flags. +*/ + +/* + ANYCHUNKS_BIT held in max_fast indicates that there may be any + freed chunks at all. It is set true when entering a chunk into any + bin. +*/ + +#define ANYCHUNKS_BIT (1U) + +#define have_anychunks(M) (((M)->max_fast & ANYCHUNKS_BIT)) +#define set_anychunks(M) ((M)->max_fast |= ANYCHUNKS_BIT) +#define clear_anychunks(M) ((M)->max_fast &= ~ANYCHUNKS_BIT) + +/* + FASTCHUNKS_BIT held in max_fast indicates that there are probably + some fastbin chunks. It is set true on entering a chunk into any + fastbin, and cleared only in __malloc_consolidate. +*/ + +#define FASTCHUNKS_BIT (2U) + +#define have_fastchunks(M) (((M)->max_fast & FASTCHUNKS_BIT)) +#define set_fastchunks(M) ((M)->max_fast |= (FASTCHUNKS_BIT|ANYCHUNKS_BIT)) +#define clear_fastchunks(M) ((M)->max_fast &= ~(FASTCHUNKS_BIT)) + +/* Set value of max_fast. Use impossibly small value if 0. */ +#define set_max_fast(M, s) \ + (M)->max_fast = (((s) == 0)? SMALLBIN_WIDTH: request2size(s)) | \ + ((M)->max_fast & (FASTCHUNKS_BIT|ANYCHUNKS_BIT)) + +#define get_max_fast(M) \ + ((M)->max_fast & ~(FASTCHUNKS_BIT | ANYCHUNKS_BIT)) + + +/* + morecore_properties is a status word holding dynamically discovered + or controlled properties of the morecore function +*/ + +#define MORECORE_CONTIGUOUS_BIT (1U) + +#define contiguous(M) \ + (((M)->morecore_properties & MORECORE_CONTIGUOUS_BIT)) +#define noncontiguous(M) \ + (((M)->morecore_properties & MORECORE_CONTIGUOUS_BIT) == 0) +#define set_contiguous(M) \ + ((M)->morecore_properties |= MORECORE_CONTIGUOUS_BIT) +#define set_noncontiguous(M) \ + ((M)->morecore_properties &= ~MORECORE_CONTIGUOUS_BIT) + + +/* + ----------- Internal state representation and initialization ----------- +*/ + +struct malloc_state { + + /* The maximum chunk size to be eligible for fastbin */ + size_t max_fast; /* low 2 bits used as flags */ + + /* Fastbins */ + mfastbinptr fastbins[NFASTBINS]; + + /* Base of the topmost chunk -- not otherwise kept in a bin */ + mchunkptr top; + + /* The remainder from the most recent split of a small request */ + mchunkptr last_remainder; + + /* Normal bins packed as described above */ + mchunkptr bins[NBINS * 2]; + + /* Bitmap of bins. Trailing zero map handles cases of largest binned size */ + unsigned int binmap[BINMAPSIZE+1]; + + /* Tunable parameters */ + unsigned long trim_threshold; + size_t top_pad; + size_t mmap_threshold; + + /* Memory map support */ + int n_mmaps; + int n_mmaps_max; + int max_n_mmaps; + + /* Cache malloc_getpagesize */ + unsigned int pagesize; + + /* Track properties of MORECORE */ + unsigned int morecore_properties; + + /* Statistics */ + size_t mmapped_mem; + size_t sbrked_mem; + size_t max_sbrked_mem; + size_t max_mmapped_mem; + size_t max_total_mem; +}; + +typedef struct malloc_state *mstate; + +/* + There is exactly one instance of this struct in this malloc. + If you are adapting this malloc in a way that does NOT use a static + malloc_state, you MUST explicitly zero-fill it before using. This + malloc relies on the property that malloc_state is initialized to + all zeroes (as is true of C statics). +*/ +extern struct malloc_state __malloc_state; /* never directly referenced */ + +/* + All uses of av_ are via get_malloc_state(). + At most one "call" to get_malloc_state is made per invocation of + the public versions of malloc and free, but other routines + that in turn invoke malloc and/or free may call more then once. + Also, it is called in check* routines if __MALLOC_DEBUGGING is set. +*/ + +#define get_malloc_state() (&(__malloc_state)) + +/* External internal utilities operating on mstates */ +void __malloc_consolidate(mstate); + + +/* Debugging support */ +#if ! __MALLOC_DEBUGGING + +#define check_chunk(P) +#define check_free_chunk(P) +#define check_inuse_chunk(P) +#define check_remalloced_chunk(P,N) +#define check_malloced_chunk(P,N) +#define check_malloc_state() +#define assert(x) ((void)0) + + +#else + +#define check_chunk(P) __do_check_chunk(P) +#define check_free_chunk(P) __do_check_free_chunk(P) +#define check_inuse_chunk(P) __do_check_inuse_chunk(P) +#define check_remalloced_chunk(P,N) __do_check_remalloced_chunk(P,N) +#define check_malloced_chunk(P,N) __do_check_malloced_chunk(P,N) +#define check_malloc_state() __do_check_malloc_state() + +extern void __do_check_chunk(mchunkptr p); +extern void __do_check_free_chunk(mchunkptr p); +extern void __do_check_inuse_chunk(mchunkptr p); +extern void __do_check_remalloced_chunk(mchunkptr p, size_t s); +extern void __do_check_malloced_chunk(mchunkptr p, size_t s); +extern void __do_check_malloc_state(void); + +#include <assert.h> + +#endif diff --git a/libc/stdlib/malloc-standard/mallopt.c b/libc/stdlib/malloc-standard/mallopt.c new file mode 100644 index 000000000..e28792099 --- /dev/null +++ b/libc/stdlib/malloc-standard/mallopt.c @@ -0,0 +1,64 @@ +/* + This is a version (aka dlmalloc) of malloc/free/realloc written by + Doug Lea and released to the public domain. Use, modify, and + redistribute this code without permission or acknowledgement in any + way you wish. Send questions, comments, complaints, performance + data, etc to dl@cs.oswego.edu + + VERSION 2.7.2 Sat Aug 17 09:07:30 2002 Doug Lea (dl at gee) + + Note: There may be an updated version of this malloc obtainable at + ftp://gee.cs.oswego.edu/pub/misc/malloc.c + Check before installing! + + Hacked up for uClibc by Erik Andersen <andersen@codepoet.org> +*/ + +#include "malloc.h" + + +/* ------------------------------ mallopt ------------------------------ */ +int mallopt(int param_number, int value) +{ + int ret; + mstate av; + + ret = 0; + + LOCK; + av = get_malloc_state(); + /* Ensure initialization/consolidation */ + __malloc_consolidate(av); + + switch(param_number) { + case M_MXFAST: + if (value >= 0 && value <= MAX_FAST_SIZE) { + set_max_fast(av, value); + ret = 1; + } + break; + + case M_TRIM_THRESHOLD: + av->trim_threshold = value; + ret = 1; + break; + + case M_TOP_PAD: + av->top_pad = value; + ret = 1; + break; + + case M_MMAP_THRESHOLD: + av->mmap_threshold = value; + ret = 1; + break; + + case M_MMAP_MAX: + av->n_mmaps_max = value; + ret = 1; + break; + } + UNLOCK; + return ret; +} + diff --git a/libc/stdlib/malloc-standard/memalign.c b/libc/stdlib/malloc-standard/memalign.c new file mode 100644 index 000000000..bd9536272 --- /dev/null +++ b/libc/stdlib/malloc-standard/memalign.c @@ -0,0 +1,126 @@ +/* + This is a version (aka dlmalloc) of malloc/free/realloc written by + Doug Lea and released to the public domain. Use, modify, and + redistribute this code without permission or acknowledgement in any + way you wish. Send questions, comments, complaints, performance + data, etc to dl@cs.oswego.edu + + VERSION 2.7.2 Sat Aug 17 09:07:30 2002 Doug Lea (dl at gee) + + Note: There may be an updated version of this malloc obtainable at + ftp://gee.cs.oswego.edu/pub/misc/malloc.c + Check before installing! + + Hacked up for uClibc by Erik Andersen <andersen@codepoet.org> +*/ + +#include <features.h> +#include <stddef.h> +#include <unistd.h> +#include <errno.h> +#include <string.h> +#include "malloc.h" + + +/* ------------------------------ memalign ------------------------------ */ +void* memalign(size_t alignment, size_t bytes) +{ + size_t nb; /* padded request size */ + char* m; /* memory returned by malloc call */ + mchunkptr p; /* corresponding chunk */ + char* brk; /* alignment point within p */ + mchunkptr newp; /* chunk to return */ + size_t newsize; /* its size */ + size_t leadsize; /* leading space before alignment point */ + mchunkptr remainder; /* spare room at end to split off */ + unsigned long remainder_size; /* its size */ + size_t size; + + /* If need less alignment than we give anyway, just relay to malloc */ + + if (alignment <= MALLOC_ALIGNMENT) return malloc(bytes); + + /* Otherwise, ensure that it is at least a minimum chunk size */ + + if (alignment < MINSIZE) alignment = MINSIZE; + + /* Make sure alignment is power of 2 (in case MINSIZE is not). */ + if ((alignment & (alignment - 1)) != 0) { + size_t a = MALLOC_ALIGNMENT * 2; + while ((unsigned long)a < (unsigned long)alignment) a <<= 1; + alignment = a; + } + + LOCK; + checked_request2size(bytes, nb); + + /* Strategy: find a spot within that chunk that meets the alignment + * request, and then possibly free the leading and trailing space. */ + + + /* Call malloc with worst case padding to hit alignment. */ + + m = (char*)(malloc(nb + alignment + MINSIZE)); + + if (m == 0) { + UNLOCK; + return 0; /* propagate failure */ + } + + p = mem2chunk(m); + + if ((((unsigned long)(m)) % alignment) != 0) { /* misaligned */ + + /* + Find an aligned spot inside chunk. Since we need to give back + leading space in a chunk of at least MINSIZE, if the first + calculation places us at a spot with less than MINSIZE leader, + we can move to the next aligned spot -- we've allocated enough + total room so that this is always possible. + */ + + brk = (char*)mem2chunk((unsigned long)(((unsigned long)(m + alignment - 1)) & + -((signed long) alignment))); + if ((unsigned long)(brk - (char*)(p)) < MINSIZE) + brk += alignment; + + newp = (mchunkptr)brk; + leadsize = brk - (char*)(p); + newsize = chunksize(p) - leadsize; + + /* For mmapped chunks, just adjust offset */ + if (chunk_is_mmapped(p)) { + newp->prev_size = p->prev_size + leadsize; + set_head(newp, newsize|IS_MMAPPED); + UNLOCK; + return chunk2mem(newp); + } + + /* Otherwise, give back leader, use the rest */ + set_head(newp, newsize | PREV_INUSE); + set_inuse_bit_at_offset(newp, newsize); + set_head_size(p, leadsize); + free(chunk2mem(p)); + p = newp; + + assert (newsize >= nb && + (((unsigned long)(chunk2mem(p))) % alignment) == 0); + } + + /* Also give back spare room at the end */ + if (!chunk_is_mmapped(p)) { + size = chunksize(p); + if ((unsigned long)(size) > (unsigned long)(nb + MINSIZE)) { + remainder_size = size - nb; + remainder = chunk_at_offset(p, nb); + set_head(remainder, remainder_size | PREV_INUSE); + set_head_size(p, nb); + free(chunk2mem(remainder)); + } + } + + check_inuse_chunk(p); + UNLOCK; + return chunk2mem(p); +} + diff --git a/libc/stdlib/malloc-standard/realloc.c b/libc/stdlib/malloc-standard/realloc.c new file mode 100644 index 000000000..195013095 --- /dev/null +++ b/libc/stdlib/malloc-standard/realloc.c @@ -0,0 +1,237 @@ +/* + This is a version (aka dlmalloc) of malloc/free/realloc written by + Doug Lea and released to the public domain. Use, modify, and + redistribute this code without permission or acknowledgement in any + way you wish. Send questions, comments, complaints, performance + data, etc to dl@cs.oswego.edu + + VERSION 2.7.2 Sat Aug 17 09:07:30 2002 Doug Lea (dl at gee) + + Note: There may be an updated version of this malloc obtainable at + ftp://gee.cs.oswego.edu/pub/misc/malloc.c + Check before installing! + + Hacked up for uClibc by Erik Andersen <andersen@codepoet.org> +*/ + +#include "malloc.h" + + + +/* ------------------------------ realloc ------------------------------ */ +void* realloc(void* oldmem, size_t bytes) +{ + mstate av; + + size_t nb; /* padded request size */ + + mchunkptr oldp; /* chunk corresponding to oldmem */ + size_t oldsize; /* its size */ + + mchunkptr newp; /* chunk to return */ + size_t newsize; /* its size */ + void* newmem; /* corresponding user mem */ + + mchunkptr next; /* next contiguous chunk after oldp */ + + mchunkptr remainder; /* extra space at end of newp */ + unsigned long remainder_size; /* its size */ + + mchunkptr bck; /* misc temp for linking */ + mchunkptr fwd; /* misc temp for linking */ + + unsigned long copysize; /* bytes to copy */ + unsigned int ncopies; /* size_t words to copy */ + size_t* s; /* copy source */ + size_t* d; /* copy destination */ + + + /* Check for special cases. */ + if (! oldmem) + return malloc(bytes); + if (! bytes) { + free (oldmem); + return malloc(bytes); + } + + LOCK; + av = get_malloc_state(); + checked_request2size(bytes, nb); + + oldp = mem2chunk(oldmem); + oldsize = chunksize(oldp); + + check_inuse_chunk(oldp); + + if (!chunk_is_mmapped(oldp)) { + + if ((unsigned long)(oldsize) >= (unsigned long)(nb)) { + /* already big enough; split below */ + newp = oldp; + newsize = oldsize; + } + + else { + next = chunk_at_offset(oldp, oldsize); + + /* Try to expand forward into top */ + if (next == av->top && + (unsigned long)(newsize = oldsize + chunksize(next)) >= + (unsigned long)(nb + MINSIZE)) { + set_head_size(oldp, nb); + av->top = chunk_at_offset(oldp, nb); + set_head(av->top, (newsize - nb) | PREV_INUSE); + UNLOCK; + return chunk2mem(oldp); + } + + /* Try to expand forward into next chunk; split off remainder below */ + else if (next != av->top && + !inuse(next) && + (unsigned long)(newsize = oldsize + chunksize(next)) >= + (unsigned long)(nb)) { + newp = oldp; + unlink(next, bck, fwd); + } + + /* allocate, copy, free */ + else { + newmem = malloc(nb - MALLOC_ALIGN_MASK); + if (newmem == 0) { + UNLOCK; + return 0; /* propagate failure */ + } + + newp = mem2chunk(newmem); + newsize = chunksize(newp); + + /* + Avoid copy if newp is next chunk after oldp. + */ + if (newp == next) { + newsize += oldsize; + newp = oldp; + } + else { + /* + Unroll copy of <= 36 bytes (72 if 8byte sizes) + We know that contents have an odd number of + size_t-sized words; minimally 3. + */ + + copysize = oldsize - (sizeof(size_t)); + s = (size_t*)(oldmem); + d = (size_t*)(newmem); + ncopies = copysize / sizeof(size_t); + assert(ncopies >= 3); + + if (ncopies > 9) + memcpy(d, s, copysize); + + else { + *(d+0) = *(s+0); + *(d+1) = *(s+1); + *(d+2) = *(s+2); + if (ncopies > 4) { + *(d+3) = *(s+3); + *(d+4) = *(s+4); + if (ncopies > 6) { + *(d+5) = *(s+5); + *(d+6) = *(s+6); + if (ncopies > 8) { + *(d+7) = *(s+7); + *(d+8) = *(s+8); + } + } + } + } + + free(oldmem); + check_inuse_chunk(newp); + UNLOCK; + return chunk2mem(newp); + } + } + } + + /* If possible, free extra space in old or extended chunk */ + + assert((unsigned long)(newsize) >= (unsigned long)(nb)); + + remainder_size = newsize - nb; + + if (remainder_size < MINSIZE) { /* not enough extra to split off */ + set_head_size(newp, newsize); + set_inuse_bit_at_offset(newp, newsize); + } + else { /* split remainder */ + remainder = chunk_at_offset(newp, nb); + set_head_size(newp, nb); + set_head(remainder, remainder_size | PREV_INUSE); + /* Mark remainder as inuse so free() won't complain */ + set_inuse_bit_at_offset(remainder, remainder_size); + free(chunk2mem(remainder)); + } + + check_inuse_chunk(newp); + UNLOCK; + return chunk2mem(newp); + } + + /* + Handle mmap cases + */ + + else { + size_t offset = oldp->prev_size; + size_t pagemask = av->pagesize - 1; + char *cp; + unsigned long sum; + + /* Note the extra (sizeof(size_t)) overhead */ + newsize = (nb + offset + (sizeof(size_t)) + pagemask) & ~pagemask; + + /* don't need to remap if still within same page */ + if (oldsize == newsize - offset) { + UNLOCK; + return oldmem; + } + + cp = (char*)mremap((char*)oldp - offset, oldsize + offset, newsize, 1); + + if (cp != (char*)MORECORE_FAILURE) { + + newp = (mchunkptr)(cp + offset); + set_head(newp, (newsize - offset)|IS_MMAPPED); + + assert(aligned_OK(chunk2mem(newp))); + assert((newp->prev_size == offset)); + + /* update statistics */ + sum = av->mmapped_mem += newsize - oldsize; + if (sum > (unsigned long)(av->max_mmapped_mem)) + av->max_mmapped_mem = sum; + sum += av->sbrked_mem; + if (sum > (unsigned long)(av->max_total_mem)) + av->max_total_mem = sum; + + UNLOCK; + return chunk2mem(newp); + } + + /* Note the extra (sizeof(size_t)) overhead. */ + if ((unsigned long)(oldsize) >= (unsigned long)(nb + (sizeof(size_t)))) + newmem = oldmem; /* do nothing */ + else { + /* Must alloc, copy, free. */ + newmem = malloc(nb - MALLOC_ALIGN_MASK); + if (newmem != 0) { + memcpy(newmem, oldmem, oldsize - 2*(sizeof(size_t))); + free(oldmem); + } + } + UNLOCK; + return newmem; + } +} + |