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View Details Posted at:12/03/2011 09:35:32 

1. #pragma  once
2. 
3. #ifdef WIN32
4. #include "Framework/Compile/Delegate.h"
5. #include "Framework/Container/Vector.h"

View Details Posted at:12/01/2011 03:11:31 

1. /* This version of malloc for VxWorks contains two different algorithms. One is the BSD based Kingsley "bucket" allocator which has some unique fragmentation behavior. The other is Doug Lea's well tested allocator that tries to minimize fragmentation while keeping the speed/space requirements. Original version of this malloc software was obtained from: Doug Lea's malloc from ftp://g.oswego.edu/pub/misc/malloc.c BSD malloc from various BSD Unix ftp sites. USE_BSD and USE_DL are ifdefs used to enable either one of these. This file is intended to replace the VxWorks memLib.o, memPartLib.o and memShow.o completely out of the system. Some of the scary looking hacks towards the end of this file which replaces some of the required VxWorks symbols can be modified to suit your needs. Typically, you would delete the objects memtioned above from your library and link this file instead, to provide memory routines. This seems to work fine in my environment. Of course, using this allocator is not compatible with memory partition handling in VxWorks. If you must use partitioning you might as well rename all the standard malloc/free/calloc, etc. to a different name in this file and link against system memLib, etc. You can still allocate a partition or large chunk of memory and give it to either BSD or DL initializer and use special names to access the allocator facilities in this file, and you can access partition handler as well. The reason for this brain damage is due to the way some routines such as malloc/free are defined in memPartLib.o and calloc etc are defined in memLib.o in VxWorks. Also some networking code and object ID code in VxWorks seems to reference global variables used in memPartLib. In short, they don't make it easy to replace or augment the memory allocator. This port to VxWorks by Hwa Jin Bae, bae@mail.com, Piedmont California. This port is released under the same license as the original license. */ #define USE_DL #define VXWORKS #define __INCmemLibh /* XXX to avoid including memLib.h */ #define __INCclassLibh #define dbg_printf printf #if defined(USE_BSD) && defined(USE_DL) XXXX only one of these can be used #endif #include "vxWorks.h" #include "semLib.h" #define VX_PAGE_SIZE 4096 /* XXX */ #ifdef USE_BSD #include "sys/types.h" #include "unistd.h" #include "assert.h" #define getpagesize() VX_PAGE_SIZE char bsd_mem_semaphore[32]; /* XXX */ SEM_ID bsd_mem_sid = (SEM_ID)bsd_mem_semaphore; /* * The overhead on a block is at least 4 bytes. When free, this space * contains a pointer to the next free block, and the bottom two bits must * be zero. When in use, the first byte is set to MAGIC, and the second * byte is the size index. The remaining bytes are for alignment. * If range checking is enabled then a second word holds the size of the * requested block, less 1, rounded up to a multiple of sizeof(RMAGIC). * The order of elements is critical: ov_magic must overlay the low order * bits of ov_next, and ov_magic can not be a valid ov_next bit pattern. */ union overhead { union overhead *ov_next; /* when free */ struct { u_char ovu_magic; /* magic number */ u_char ovu_index; /* bucket # */ u_short ovu_rmagic; /* range magic number */ u_int ovu_size; /* actual block size */ } ovu; #define ov_magic ovu.ovu_magic #define ov_index ovu.ovu_index #define ov_rmagic ovu.ovu_rmagic #define ov_size ovu.ovu_size }; #define MAGIC 0xef /* magic # on accounting info */ #define RMAGIC 0x5555 /* magic # on range info */ #define RSLOP sizeof (u_short) /* * nextf[i] is the pointer to the next free block of size 2^(i+3). The * smallest allocatable block is 8 bytes. The overhead information * precedes the data area returned to the user. */ #define NBUCKETS 30 static union overhead *nextf[NBUCKETS]; extern char *sbrk(); static int pagesz = 0; /* page size */ static int pagebucket = 0; /* page size bucket */ /* * nmalloc[i] is the difference between the number of mallocs and frees * for a given block size. */ static u_int nmalloc[NBUCKETS]; char *bsd_malloc_bottom = 0; char *bsd_malloc_top = 0; char *bsd_malloc_brk = 0; int bsd_malloc_initialized = 0; int mem_added_to_pool = 0; #define INFINITE 100000 /* XXX */ static void morecore(); static int findbucket(); extern void *bsd_malloc(size_t nbytes); extern void bsd_free(void *cp); extern void * bsd_realloc(void *cp, int nbytes); #endif /* USE_BSD */ #ifdef USE_DL #define malloc_getpagesize VX_PAGE_SIZE char dl_mem_semaphore[32]; /* XXX */ SEM_ID dl_mem_sid = (SEM_ID)dl_mem_semaphore; #define Void_t void #define INTERNAL_SIZE_T size_t struct mallinfo { int arena; /* total space allocated from system */ int ordblks; /* number of non-inuse chunks */ int smblks; /* unused -- always zero */ int hblks; /* number of mmapped regions */ int hblkhd; /* total space in mmapped regions */ int usmblks; /* unused -- always zero */ int fsmblks; /* unused -- always zero */ int uordblks; /* total allocated space */ int fordblks; /* total non-inuse space */ int keepcost; /* top-most, releasable (via malloc_trim) space */ }; #define M_MXFAST 1 /* UNUSED in this malloc */ #define M_NLBLKS 2 /* UNUSED in this malloc */ #define M_GRAIN 3 /* UNUSED in this malloc */ #define M_KEEP 4 /* UNUSED in this malloc */ static int cumblocks=0; static int cumbytes = 0; /* mallopt options that actually do something */ #define M_TRIM_THRESHOLD -1 #define M_TOP_PAD -2 #define M_MMAP_THRESHOLD -3 #define M_MMAP_MAX -4 #define DEFAULT_TRIM_THRESHOLD (128 * 1024) #define DEFAULT_TOP_PAD (0) #define MORECORE sbrk #define MORECORE_FAILURE -1 #define MORECORE_CLEARS 0 Void_t* mALLoc(); void fREe(Void_t*); Void_t* reALLoc(Void_t*, size_t); Void_t* mEMALIGn(size_t, size_t); Void_t* cALLoc(size_t, size_t); int malloc_trim(size_t); size_t malloc_usable_size(Void_t*); void malloc_stats(); int mALLOPt(int, int); struct mallinfo mALLINFo(void); struct malloc_chunk { INTERNAL_SIZE_T prev_size; /* Size of previous chunk (if free). */ INTERNAL_SIZE_T size; /* Size in bytes, including overhead. */ struct malloc_chunk* fd; /* double links -- used only if free. */ struct malloc_chunk* bk; }; typedef struct malloc_chunk* mchunkptr; void *mALLoc(size_t sz); void fREe(void *ptr); #include "assert.h" #define _ASSERT_STR(z) _ASSERT_TMP(z) #define _ASSERT_TMP(z) #z #define ASSERT(test) ((void) \ ((test) ? ((void) 0) : \ dl_assert("Assertion failed: "#test", file " \ __FILE__ ", line "_ASSERT_STR(__LINE__)" "))) #define PREV_INUSE 0x1 char *dl_malloc_bottom = 0; char *dl_malloc_top = 0; char *dl_malloc_brk = 0; int dl_malloc_initialized = 0; #endif #ifdef USE_BSD #include "vxWorks.h" #include "semLib.h" /* * Copyright (c) 1983 Regents of the University of California. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ /* * malloc.c (Caltech) 2/21/82 * Chris Kingsley, kingsley@cit-20. * * This is a very fast storage allocator. It allocates blocks of a small * number of different sizes, and keeps free lists of each size. Blocks that * don't exactly fit are passed up to the next larger size. In this * implementation, the available sizes are 2^n-4 (or 2^n-10) bytes long. * This is designed for use in a virtual memory environment. */ int bsd_malloc_init(char *cp, int sz) { if (bsd_malloc_initialized) { dbg_printf("bsd_malloc_init: already initialized\n"); return -1; } bsd_malloc_bottom = cp; bsd_malloc_brk = cp; /* brk pointer currently at bottom */ bsd_malloc_top = cp + sz; bsd_malloc_initialized ++; bzero((char *)nmalloc, sizeof(nmalloc)); bzero((char *)nextf, sizeof(nextf)); bzero((char *)cp, sz); /* zero out the entire memory pool */ semMInit(bsd_mem_sid, SEM_Q_PRIORITY); return 1; } char * sbrk(int sz) { char *cp; int orig_sz = sz; if (bsd_malloc_initialized == 0) return (char *)-1; sz = (sz + 3) & ~3; /* align sz to 4 bytes */ cp = bsd_malloc_brk; if (bsd_malloc_brk + sz >= bsd_malloc_top) return (char *)-1; if (orig_sz == 0) return cp; bsd_malloc_brk += sz; return cp; } void * bsd_malloc(size_t nbytes) { register union overhead *op; register int bucket, n; register unsigned amt; bucket = 0; assert(bsd_malloc_initialized); semTake(bsd_mem_sid, WAIT_FOREVER); if (pagesz == 0) { pagesz = n = getpagesize(); op = (union overhead *)sbrk(0); n = n - sizeof (*op) - ((int)op & (n - 1)); if (n < 0) n += pagesz; if (n) { if (sbrk(n) == (char *)-1) { semGive(bsd_mem_sid); return (NULL); } } bucket = 0; amt = 8; while (pagesz > amt) { amt <<= 1; bucket++; } pagebucket = bucket; } /* * Convert amount of memory requested into closest block size * stored in hash buckets which satisfies request. * Account for space used per block for accounting. */ if (nbytes <= (n = pagesz - sizeof (*op) - RSLOP)) { amt = 16; /* size of first bucket */ bucket = 1; n = -(sizeof (*op) + RSLOP); } else { amt = pagesz; bucket = pagebucket; } while (nbytes > amt + n) { amt <<= 1; if (amt == 0) { semGive(bsd_mem_sid); return (NULL); } bucket++; } if (!(bucket >= 0 && bucket < NBUCKETS)) { dbg_printf("bsd malloc: bucket %d nbytes %d\n", bucket, nbytes); panic("bsd malloc"); } /* * If nothing in hash bucket right now, * request more memory from the system. */ if ((op = nextf[bucket]) == NULL) { morecore(bucket); if ((op = nextf[bucket]) == NULL) { semGive(bsd_mem_sid); return (NULL); } } /* remove from linked list */ nextf[bucket] = op->ov_next; op->ov_magic = MAGIC; op->ov_index = bucket; nmalloc[bucket]++; /* * Record allocated size of block and * bound space with magic numbers. */ op->ov_size = (nbytes + RSLOP - 1) & ~(RSLOP - 1); op->ov_rmagic = RMAGIC; *(u_short *)((caddr_t)(op + 1) + op->ov_size) = RMAGIC; semGive(bsd_mem_sid); return ((char *)(op + 1)); } /* * Allocate more memory to the indicated bucket. */ static void morecore(bucket) int bucket; { register union overhead *op; register int sz; /* size of desired block */ int amt; /* amount to allocate */ int nblks; /* how many blocks we get */ /* * sbrk_size <= 0 only for big, FLUFFY, requests (about * 2^30 bytes on a VAX, I think) or for a negative arg. */ sz = 1 << (bucket + 3); if (sz <= 0) return; if (sz < pagesz) { amt = pagesz; nblks = amt / sz; } else { amt = sz + pagesz; nblks = 1; } op = (union overhead *)sbrk(amt); /* no more room! */ if ((int)op == -1) return; /* * Add new memory allocated to that on * free list for this hash bucket. */ nextf[bucket] = op; while (--nblks > 0) { op->ov_next = (union overhead *)((caddr_t)op + sz); op = (union overhead *)((caddr_t)op + sz); } } void bsd_free(void *cp) { register int size; register union overhead *op; assert(bsd_malloc_initialized); if (cp == NULL) return; semTake(bsd_mem_sid, WAIT_FOREVER); op = (union overhead *)((caddr_t)cp - sizeof (union overhead)); if (op->ov_magic != MAGIC) { semGive(bsd_mem_sid); return; /* sanity */ } assert(op->ov_rmagic == RMAGIC); assert(*(u_short *)((caddr_t)(op + 1) + op->ov_size) == RMAGIC); size = op->ov_index; assert(size < NBUCKETS); op->ov_next = nextf[size]; /* also clobbers ov_magic */ nextf[size] = op; nmalloc[size]--; semGive(bsd_mem_sid); } /* * When a program attempts "storage compaction" as mentioned in the * old malloc man page, it realloc's an already freed block. Usually * this is the last block it freed; occasionally it might be farther * back. We have to search all the free lists for the block in order * to determine its bucket: 1st we make one pass thru the lists * checking only the first block in each; if that fails we search * ``realloc_srchlen'' blocks in each list for a match (the variable * is extern so the caller can modify it). If that fails we just copy * however many bytes was given to realloc() and hope it's not huge. */ int realloc_srchlen = 4; /* 4 should be plenty, -1 =>'s whole list */ void * bsd_realloc(void *cp, int nbytes) { register u_int onb; register int i; union overhead *op; char *res; int was_alloced = 0; assert(bsd_malloc_initialized); semTake(bsd_mem_sid, WAIT_FOREVER); if (cp == NULL) { semGive(bsd_mem_sid); return (bsd_malloc(nbytes)); } op = (union overhead *)((caddr_t)cp - sizeof (union overhead)); if (op->ov_magic == MAGIC) { was_alloced++; i = op->ov_index; } else { /* * Already free, doing "compaction". * * Search for the old block of memory on the * free list. First, check the most common * case (last element free'd), then (this failing) * the last ``realloc_srchlen'' items free'd. * If all lookups fail, then assume the size of * the memory block being realloc'd is the * largest possible (so that all "nbytes" of new * memory are copied into). Note that this could cause * a memory fault if the old area was tiny, and the moon * is gibbous. However, that is very unlikely. */ if ((i = findbucket(op, 1)) < 0 && (i = findbucket(op, realloc_srchlen)) < 0) i = NBUCKETS; } onb = 1 << (i + 3); if (onb < pagesz) onb -= sizeof (*op) + RSLOP; else onb += pagesz - sizeof (*op) - RSLOP; /* avoid the copy if same size block */ if (was_alloced) { if (i) { i = 1 << (i + 2); if (i < pagesz) i -= sizeof (*op) + RSLOP; else i += pagesz - sizeof (*op) - RSLOP; } if (nbytes <= onb && nbytes > i) { op->ov_size = (nbytes + RSLOP - 1) & ~(RSLOP - 1); *(u_short *)((caddr_t)(op + 1) + op->ov_size) = RMAGIC; semGive(bsd_mem_sid); return(cp); } else bsd_free(cp); } if ((res = bsd_malloc(nbytes)) == NULL) { semGive(bsd_mem_sid); return (NULL); } if (cp != res) /* common optimization if "compacting" */ bcopy(cp, res, (nbytes < onb) ? nbytes : onb); semGive(bsd_mem_sid); return (res); } /* * Search ``srchlen'' elements of each free list for a block whose * header starts at ``freep''. If srchlen is -1 search the whole list. * Return bucket number, or -1 if not found. */ static int findbucket(freep, srchlen) union overhead *freep; int srchlen; { register union overhead *p; register int i, j; for (i = 0; i < NBUCKETS; i++) { j = 0; for (p = nextf[i]; p && j != srchlen; p = p->ov_next) { if (p == freep) return (i); j++; } } return (-1); } /* * mstats - print out statistics about malloc * * Prints two lines of numbers, one showing the length of the free list * for each size category, the second showing the number of mallocs - * frees for each size category. */ void bsd_mstats(int mode) { register int i, j; register union overhead *p; unsigned int totfree = 0, totused = 0; dbg_printf("\nBSD memory allocation statistics\n"); if (mode) { dbg_printf("%12s size %12s free %10s used\n"," ", " ", " "); for (i = 0; i < NBUCKETS; i++) { for (j = 0, p = nextf[i]; p && j < INFINITE; p = p->ov_next, j++) ; if (j == INFINITE) /* just in case something is corrupted */ { dbg_printf("\nToo many links in block %d(%u)!\n", i, (1<< (i+3))); return; } dbg_printf("%16u: %16u %16u\n", (1<< (i + 3)), j, nmalloc[i]); totfree += j * (1 << (i + 3)); totused += nmalloc[i] * (1 << (i+3)); } } dbg_printf("\n"); dbg_printf("\tbytes in use: %16u\n", totused); dbg_printf("\tbytes free: %16u\n", totfree); dbg_printf("\tpool size: %16d\n", (int)(bsd_malloc_top - bsd_malloc_bottom)); dbg_printf("\tmargin: %16d\n", (int)(bsd_malloc_top - bsd_malloc_brk)); dbg_printf("\n"); dbg_printf("\tbottom: 0x%x\n", (int)bsd_malloc_bottom); dbg_printf("\ttop: 0x%x\n", (int)bsd_malloc_top); dbg_printf("\tbrk: 0x%x\n", (int)bsd_malloc_brk); } #endif /* USE_BSD */ #ifdef USE_DL /* A version of malloc/free/realloc written by Doug Lea and released to the public domain. Send questions/comments/complaints/performance data to dl@cs.oswego.edu */ /* VERSION 2.6.2 Mon Jan 8 10:28:33 1996 Doug Lea (dl at gee) Note: There may be an updated version of this malloc obtainable at ftp://g.oswego.edu/pub/misc/malloc.c Check before installing! * Synopsis of public routines (Much fuller descriptions are contained in the program documentation below.) malloc(size_t n); Return a pointer to a newly allocated chunk of at least n bytes, or null if no space is available. free(Void_t* p); Release the chunk of memory pointed to by p, or no effect if p is null. realloc(Void_t* p, size_t n); Return a pointer to a chunk of size n that contains the same data as does chunk p up to the minimum of (n, p's size) bytes, or null if no space is available. The returned pointer may or may not be the same as p. If p is null, equivalent to malloc. Unless the #define REALLOC_ZERO_BYTES_FREES below is set, realloc with a size argument of zero (re)allocates a minimum-sized chunk. memalign(size_t alignment, size_t n); Return a pointer to a newly allocated chunk of n bytes, aligned in accord with the alignment argument, which must be a power of two. valloc(size_t n); Equivalent to memalign(pagesize, n), where pagesize is the page size of the system (or as near to this as can be figured out from all the includes/defines below.) calloc(size_t unit, size_t quantity); Returns a pointer to quantity * unit bytes, with all locations set to zero. cfree(Void_t* p); Equivalent to free(p). malloc_trim(size_t pad); Release all but pad bytes of freed top-most memory back to the system. Return 1 if successful, else 0. malloc_usable_size(Void_t* p); Report the number usable allocated bytes associated with allocated chunk p. This may or may not report more bytes than were requested, due to alignment and minimum size constraints. malloc_stats(); Prints brief summary statistics on stderr. mallinfo() Returns (by copy) a struct containing various summary statistics. mallopt(int parameter_number, int parameter_value) Changes one of the tunable parameters described below. Returns 1 if successful in changing the parameter, else 0. * Vital statistics: Alignment: 8-byte 8 byte alignment is currently hardwired into the design. This seems to suffice for all current machines and C compilers. Assumed pointer representation: 4 bytes Assumed size_t representation: 4 bytes Minimum overhead per allocated chunk: 4 bytes Each malloced chunk has a hidden overhead of 4 bytes holding size and status information. Minimum allocated size: 16 bytes (12 bytes usable, 4 overhead) When a chunk is freed, 12 additional bytes are needed; 4 for a trailing size field and 8 bytes for free list pointers. Thus, the minimum allocatable size is 16 bytes, of which 12 bytes are usable. Even a request for zero bytes (i.e., malloc(0)) returns a pointer to something of the minimum allocatable size. Maximum allocated size: 2147483640 (2^31 - 8) bytes It is assumed that (possibly signed) 32 bit values suffice to represent chunk sizes. `Possibly signed' is due to the fact that `size_t' may be defined on a system as either a signed or an unsigned type. To be conservative, values that would appear as negative numbers are avoided. The maximum size chunk is 2^31 - 8 bytes. Requests for negative sizes (when size_t is signed) or those greater than (2^31 - 8) bytes will return a minimum-sized chunk. Maximum overhead wastage per allocated chunk: normally 15 bytes Alignnment demands, plus the minimum allocatable size restriction make the normal worst-case wastage 15 bytes (i.e., up to 15 more bytes will be allocated than were requested in malloc), with two exceptions: 1. Because requests for zero bytes allocate non-zero space, the worst case wastage for a request of zero bytes is 24 bytes. 2. For requests >= mmap_threshold that are serviced via mmap(), the worst case wastage is 8 bytes plus the remainder from a system page (the minimal mmap unit); typically 4096 bytes. * Synopsis of compile-time options: People have reported using previous versions of this malloc on all versions of Unix, sometimes by tweaking some of the defines below. It has been tested most extensively on Solaris and Linux. People have also reported adapting this malloc for use in stand-alone embedded systems. The implementation is in straight, hand-tuned ANSI C. Among other consequences, it uses a lot of macros. Because of this, to be at all usable, this code should be compiled using an optimizing compiler (for example gcc -O2) that can simplify expressions and control paths. __STD_C (default: derived from C compiler defines) Nonzero if using ANSI-standard C compiler, a C++ compiler, or a C compiler sufficiently close to ANSI to get away with it. DEBUG (default: NOT defined) Define to enable debugging. Adds fairly extensive assertion-based checking to help track down memory errors, but noticeably slows down execution. REALLOC_ZERO_BYTES_FREES (default: NOT defined) Define this if you think that realloc(p, 0) should be equivalent to free(p). Otherwise, since malloc returns a unique pointer for malloc(0), so does realloc(p, 0). HAVE_MEMCPY (default: defined) Define if you are not otherwise using ANSI STD C, but still have memcpy and memset in your C library and want to use them. Otherwise, simple internal versions are supplied. HAVE_MMAP (default: defined as 1) Define to non-zero to optionally make malloc() use mmap() to allocate very large blocks. malloc_getpagesize (default: derived from system #includes) Either a constant or routine call returning the system page size. HAVE_USR_INCLUDE_MALLOC_H (default: NOT defined) Optionally define if you are on a system with a /usr/include/malloc.h that declares struct mallinfo. It is not at all necessary to define this even if you do, but will ensure consistency. INTERNAL_LINUX_C_LIB (default: NOT defined) Defined only when compiled as part of Linux libc. Also note that there is some odd internal name-magling via defines (for example, internally, `malloc' is named `mALLOc') needed when compiling in this case. These look funny but don't otherwise affect anything. MORECORE (default: sbrk) The name of the routine to call to obtain more memory from the system. MORECORE_FAILURE (default: -1) The value returned upon failure of MORECORE. DEFAULT_TRIM_THRESHOLD DEFAULT_TOP_PAD DEFAULT_MMAP_THRESHOLD DEFAULT_MMAP_MAX Default values of tunable parameters (described in detail below) controlling interaction with host system routines (sbrk, mmap, etc). These values may also be changed dynamically via mallopt(). The preset defaults are those that give best performance for typical programs/systems. */ /* History: V2.6.2 Tue Dec 5 06:52:55 1995 Doug Lea (dl at gee) * Integrated most documentation with the code. * Add support for mmap, with help from Wolfram Gloger (Gloger@lrz.uni-muenchen.de). * Use last_remainder in more cases. * Pack bins using idea from colin@nyx10.cs.du.edu * Use ordered bins instead of best-fit threshhold * Eliminate block-local decls to simplify tracing and debugging. * Support another case of realloc via move into top * Fix error occuring when initial sbrk_base not word-aligned. * Rely on page size for units instead of SBRK_UNIT to avoid surprises about sbrk alignment conventions. * Add mallinfo, mallopt. Thanks to Raymond Nijssen (raymond@es.ele.tue.nl) for the suggestion. * Add `pad' argument to malloc_trim and top_pad mallopt parameter. * More precautions for cases where other routines call sbrk, courtesy of Wolfram Gloger (Gloger@lrz.uni-muenchen.de). * Added macros etc., allowing use in linux libc from H.J. Lu (hjl@gnu.ai.mit.edu) * Inverted this history list V2.6.1 Sat Dec 2 14:10:57 1995 Doug Lea (dl at gee) * Re-tuned and fixed to behave more nicely with V2.6.0 changes. * Removed all preallocation code since under current scheme the work required to undo bad preallocations exceeds the work saved in good cases for most test programs. * No longer use return list or unconsolidated bins since no scheme using them consistently outperforms those that don't given above changes. * Use best fit for very large chunks to prevent some worst-cases. * Added some support for debugging V2.6.0 Sat Nov 4 07:05:23 1995 Doug Lea (dl at gee) * Removed footers when chunks are in use. Thanks to Paul Wilson (wilson@cs.texas.edu) for the suggestion. V2.5.4 Wed Nov 1 07:54:51 1995 Doug Lea (dl at gee) * Added malloc_trim, with help from Wolfram Gloger (wmglo@Dent.MED.Uni-Muenchen.DE). V2.5.3 Tue Apr 26 10:16:01 1994 Doug Lea (dl at g) V2.5.2 Tue Apr 5 16:20:40 1994 Doug Lea (dl at g) * realloc: try to expand in both directions * malloc: swap order of clean-bin strategy; * realloc: only conditionally expand backwards * Try not to scavenge used bins * Use bin counts as a guide to preallocation * Occasionally bin return list chunks in first scan * Add a few optimizations from colin@nyx10.cs.du.edu V2.5.1 Sat Aug 14 15:40:43 1993 Doug Lea (dl at g) * faster bin computation & slightly different binning * merged all consolidations to one part of malloc proper (eliminating old malloc_find_space & malloc_clean_bin) * Scan 2 returns chunks (not just 1) * Propagate failure in realloc if malloc returns 0 * Add stuff to allow compilation on non-ANSI compilers from kpv@research.att.com V2.5 Sat Aug 7 07:41:59 1993 Doug Lea (dl at g.oswego.edu) * removed potential for odd address access in prev_chunk * removed dependency on getpagesize.h * misc cosmetics and a bit more internal documentation * anticosmetics: mangled names in macros to evade debugger strangeness * tested on sparc, hp-700, dec-mips, rs6000 with gcc & native cc (hp, dec only) allowing Detlefs & Zorn comparison study (in SIGPLAN Notices.) Trial version Fri Aug 28 13:14:29 1992 Doug Lea (dl at g.oswego.edu) * Based loosely on libg++-1.2X malloc. (It retains some of the overall structure of old version, but most details differ.) */ int dl_assert(char *msg) { logMsg(*msg,0,0,0,0,0,0); taskSuspend(0); } int dl_malloc_init(char *cp, int sz) { mchunkptr p; if (dl_malloc_initialized > 0) { dbg_printf("dl_malloc_init: already initialized\n"); return -1; } dl_malloc_bottom = cp; dl_malloc_brk = cp; /* brk pointer currently at bottom */ dl_malloc_top = cp + sz; dl_malloc_initialized ++; /*p = (mchunkptr ) cp; p ->size = sz | PREV_INUSE; */ semMInit(dl_mem_sid, SEM_Q_PRIORITY); dbg_printf("dl malloc initialized!\n"); return 1; } char * sbrk(int sz) { char *cp; if (dl_malloc_initialized == 0) { dbg_printf("sbrk: bsd_malloc package not yet intialized\n"); return (char *)-1; } cp = dl_malloc_brk; if (sz == 0) return cp; if (dl_malloc_brk + sz >= dl_malloc_top) { dbg_printf("sbrk: can't alloc %d bytes\n", sz); return (char *)-1; } sz = (sz + 3) & ~3; /* align sz to 4 bytes */ dl_malloc_brk += sz; return cp; } /* malloc_chunk details: (The following includes lightly edited explanations by Colin Plumb.) Chunks of memory are maintained using a `boundary tag' method as described in e.g., Knuth or Standish. (See the paper by Paul Wilson ftp://ftp.cs.utexas.edu/pub/garbage/allocsrv.ps for a survey of such techniques.) Sizes of free chunks are stored both in the front of each chunk and at the end. This makes consolidating fragmented chunks into bigger chunks very fast. The size fields also hold bits representing whether chunks are free or in use. An allocated chunk looks like this: chunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Size of previous chunk, if allocated | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Size of chunk, in bytes |P| mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | User data starts here... . . . . (malloc_usable_space() bytes) . . | nextchunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Size of chunk | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Where "chunk" is the front of the chunk for the purpose of most of the malloc code, but "mem" is the pointer that is returned to the user. "Nextchunk" is the beginning of the next contiguous chunk. Chunks always begin on even word boundries, so the mem portion (which is returned to the user) is also on an even word boundary, and thus double-word aligned. Free chunks are stored in circular doubly-linked lists, and look like this: chunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Size of previous chunk | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ `head:' | Size of chunk, in bytes |P| mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Forward pointer to next chunk in list | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Back pointer to previous chunk in list | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Unused space (may be 0 bytes long) . . . . | nextchunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ `foot:' | Size of chunk, in bytes | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ The P (PREV_INUSE) bit, stored in the unused low-order bit of the chunk size (which is always a multiple of two words), is an in-use bit for the *previous* chunk. If that bit is *clear*, then the word before the current chunk size contains the previous chunk size, and can be used to find the front of the previous chunk. (The very first chunk allocated always has this bit set, preventing access to non-existent (or non-owned) memory.) Note that the `foot' of the current chunk is actually represented as the prev_size of the NEXT chunk. (This makes it easier to deal with alignments etc). The two exceptions to all this are 1. The special chunk `top', which doesn't bother using the trailing size field since there is no next contiguous chunk that would have to index off it. (After initialization, `top' is forced to always exist. If it would become less than MINSIZE bytes long, it is replenished via malloc_extend_top.) 2. Chunks allocated via mmap, which have the second-lowest-order bit (IS_MMAPPED) set in their size fields. Because they are never merged or traversed from any other chunk, they have no foot size or inuse information. Available chunks are kept in any of several places (all declared below): * `av': An array of chunks serving as bin headers for consolidated chunks. Each bin is doubly linked. The bins are approximately proportionally (log) spaced. There are a lot of these bins (128). This may look excessive, but works very well in practice. All procedures maintain the invariant that no consolidated chunk physically borders another one. Chunks in bins are kept in size order, with ties going to the approximately least recently used chunk. The chunks in each bin are maintained in decreasing sorted order by size. This is irrelevant for the small bins, which all contain the same-sized chunks, but facilitates best-fit allocation for larger chunks. (These lists are just sequential. Keeping them in order almost never requires enough traversal to warrant using fancier ordered data structures.) Chunks of the same size are linked with the most recently freed at the front, and allocations are taken from the back. This results in LRU or FIFO allocation order, which tends to give each chunk an equal opportunity to be consolidated with adjacent freed chunks, resulting in larger free chunks and less fragmentation. * `top': The top-most available chunk (i.e., the one bordering the end of available memory) is treated specially. It is never included in any bin, is used only if no other chunk is available, and is released back to the system if it is very large (see M_TRIM_THRESHOLD). * `last_remainder': A bin holding only the remainder of the most recently split (non-top) chunk. This bin is checked before other non-fitting chunks, so as to provide better locality for runs of sequentially allocated chunks. * Implicitly, through the host system's memory mapping tables. If supported, requests greater than a threshold are usually serviced via calls to mmap, and then later released via munmap. */ /* sizes, alignments */ #define SIZE_SZ (sizeof(INTERNAL_SIZE_T)) #define MALLOC_ALIGNMENT (16) #define MALLOC_ALIGN_MASK (MALLOC_ALIGNMENT - 1) /*#define MINSIZE (sizeof(struct malloc_chunk)) */ #define MINSIZE 32 /* conversion from malloc headers to user pointers, and back */ #define chunk2mem(p) ((Void_t*)((char*)(p) + 2*SIZE_SZ)) #define mem2chunk(mem) ((mchunkptr)((char*)(mem) - 2*SIZE_SZ)) /* pad request bytes into a usable size */ #define request2size(req) \ (((long)((req) + (SIZE_SZ + MALLOC_ALIGN_MASK)) < \ (long)(MINSIZE + MALLOC_ALIGN_MASK)) ? MINSIZE : \ (((req) + (SIZE_SZ + MALLOC_ALIGN_MASK)) & ~(MALLOC_ALIGN_MASK))) /* Check if m has acceptable alignment */ #define aligned_OK(m) (((unsigned long)((m)) & (MALLOC_ALIGN_MASK)) == 0) /* Physical chunk operations */ /* size field is or'ed with PREV_INUSE when previous adjacent chunk in use */ #define PREV_INUSE 0x1 /* Bits to mask off when extracting size */ #define SIZE_BITS (PREV_INUSE) /* Ptr to next physical malloc_chunk. */ #define next_chunk(p) ((mchunkptr)( ((char*)(p)) + ((p)->size & ~PREV_INUSE) )) /* Ptr to previous physical malloc_chunk */ #define prev_chunk(p)\ ((mchunkptr)( ((char*)(p)) - ((p)->prev_size) )) /* Treat space at ptr + offset as a chunk */ #define chunk_at_offset(p, s) ((mchunkptr)(((char*)(p)) + (s))) /* Dealing with use bits */ /* extract p's inuse bit */ #define inuse(p)\ ((((mchunkptr)(((char*)(p))+((p)->size & ~PREV_INUSE)))->size) & PREV_INUSE) /* extract inuse bit of previous chunk */ #define prev_inuse(p) ((p)->size & PREV_INUSE) /* set/clear chunk as in use without otherwise disturbing */ #define set_inuse(p)\ ((mchunkptr)(((char*)(p)) + ((p)->size & ~PREV_INUSE)))->size |= PREV_INUSE #define clear_inuse(p)\ ((mchunkptr)(((char*)(p)) + ((p)->size & ~PREV_INUSE)))->size &= ~(PREV_INUSE) /* check/set/clear inuse bits in known places */ #define inuse_bit_at_offset(p, s)\ (((mchunkptr)(((char*)(p)) + (s)))->size & PREV_INUSE) #define set_inuse_bit_at_offset(p, s)\ (((mchunkptr)(((char*)(p)) + (s)))->size |= PREV_INUSE) #define clear_inuse_bit_at_offset(p, s)\ (((mchunkptr)(((char*)(p)) + (s)))->size &= ~(PREV_INUSE)) /* Dealing with size fields */ /* Get size, ignoring use bits */ #define chunksize(p) ((p)->size & ~(SIZE_BITS)) /* Set size at head, without disturbing its use bit */ #define set_head_size(p, s) ((p)->size = (((p)->size & PREV_INUSE) | (s))) /* Set size/use ignoring previous bits in header */ #define set_head(p, s) ((p)->size = (s)) /* Set size at footer (only when chunk is not in use) */ #define set_foot(p, s) (((mchunkptr)((char*)(p) + (s)))->prev_size = (s)) /* Bins The bins, `av_' are an array of pairs of pointers serving as the heads of (initially empty) doubly-linked lists of chunks, laid out in a way so that each pair can be treated as if it were in a malloc_chunk. (This way, the fd/bk offsets for linking bin heads and chunks are the same). Bins for sizes < 512 bytes contain chunks of all the same size, spaced 8 bytes apart. Larger bins are approximately logarithmically spaced. (See the table below.) The `av_' array is never mentioned directly in the code, but instead via bin access macros. Bin layout: 64 bins of size 8 32 bins of size 64 16 bins of size 512 8 bins of size 4096 4 bins of size 32768 2 bins of size 262144 1 bin of size what's left There is actually a little bit of slop in the numbers in bin_index for the sake of speed. This makes no difference elsewhere. The special chunks `top' and `last_remainder' get their own bins, (this is implemented via yet more trickery with the av_ array), although `top' is never properly linked to its bin since it is always handled specially. */ #define NAV 128 /* number of bins */ typedef struct malloc_chunk* mbinptr; /* access macros */ #define bin_at(i) ((mbinptr)((char*)&(av_[2*(i) + 2]) - 2*SIZE_SZ)) #define next_bin(b) ((mbinptr)((char*)(b) + 2 * sizeof(mbinptr))) #define prev_bin(b) ((mbinptr)((char*)(b) - 2 * sizeof(mbinptr))) /* The first 2 bins are never indexed. The corresponding av_ cells are instead used for bookkeeping. This is not to save space, but to simplify indexing, maintain locality, and avoid some initialization tests. */ #define top (bin_at(0)->fd) /* The topmost chunk */ #define last_remainder (bin_at(1)) /* remainder from last split */ /* Because top initially points to its own bin with initial zero size, thus forcing extension on the first malloc request, we avoid having any special code in malloc to check whether it even exists yet. But we still need to in malloc_extend_top. */ #define initial_top ((mchunkptr)(bin_at(0))) /* Helper macro to initialize bins */ #define IAV(i) bin_at(i), bin_at(i) mbinptr av_[NAV * 2 + 2] = { 0, 0, IAV(0), IAV(1), IAV(2), IAV(3), IAV(4), IAV(5), IAV(6), IAV(7), IAV(8), IAV(9), IAV(10), IAV(11), IAV(12), IAV(13), IAV(14), IAV(15), IAV(16), IAV(17), IAV(18), IAV(19), IAV(20), IAV(21), IAV(22), IAV(23), IAV(24), IAV(25), IAV(26), IAV(27), IAV(28), IAV(29), IAV(30), IAV(31), IAV(32), IAV(33), IAV(34), IAV(35), IAV(36), IAV(37), IAV(38), IAV(39), IAV(40), IAV(41), IAV(42), IAV(43), IAV(44), IAV(45), IAV(46), IAV(47), IAV(48), IAV(49), IAV(50), IAV(51), IAV(52), IAV(53), IAV(54), IAV(55), IAV(56), IAV(57), IAV(58), IAV(59), IAV(60), IAV(61), IAV(62), IAV(63), IAV(64), IAV(65), IAV(66), IAV(67), IAV(68), IAV(69), IAV(70), IAV(71), IAV(72), IAV(73), IAV(74), IAV(75), IAV(76), IAV(77), IAV(78), IAV(79), IAV(80), IAV(81), IAV(82), IAV(83), IAV(84), IAV(85), IAV(86), IAV(87), IAV(88), IAV(89), IAV(90), IAV(91), IAV(92), IAV(93), IAV(94), IAV(95), IAV(96), IAV(97), IAV(98), IAV(99), IAV(100), IAV(101), IAV(102), IAV(103), IAV(104), IAV(105), IAV(106), IAV(107), IAV(108), IAV(109), IAV(110), IAV(111), IAV(112), IAV(113), IAV(114), IAV(115), IAV(116), IAV(117), IAV(118), IAV(119), IAV(120), IAV(121), IAV(122), IAV(123), IAV(124), IAV(125), IAV(126), IAV(127) }; /* field-extraction macros */ #define first(b) ((b)->fd) #define last(b) ((b)->bk) /* Indexing into bins */ #define bin_index(sz) \ (((((unsigned long)(sz)) >> 9) == 0) ? (((unsigned long)(sz)) >> 3): \ ((((unsigned long)(sz)) >> 9) <= 4) ? 56 + (((unsigned long)(sz)) >> 6): \ ((((unsigned long)(sz)) >> 9) <= 20) ? 91 + (((unsigned long)(sz)) >> 9): \ ((((unsigned long)(sz)) >> 9) <= 84) ? 110 + (((unsigned long)(sz)) >> 12): \ ((((unsigned long)(sz)) >> 9) <= 340) ? 119 + (((unsigned long)(sz)) >> 15): \ ((((unsigned long)(sz)) >> 9) <= 1364) ? 124 + (((unsigned long)(sz)) >> 18): \ 126) /* bins for chunks < 512 are all spaced 8 bytes apart, and hold identically sized chunks. This is exploited in malloc. */ #define MAX_SMALLBIN 63 #define MAX_SMALLBIN_SIZE 512 #define SMALLBIN_WIDTH 8 #define smallbin_index(sz) (((unsigned long)(sz)) >> 3) /* Requests are `small' if both the corresponding and the next bin are small */ #define is_small_request(nb) (nb < MAX_SMALLBIN_SIZE - SMALLBIN_WIDTH) /* To help compensate for the large number of bins, a one-level index structure is used for bin-by-bin searching. `binblocks' is a one-word bitvector recording whether groups of BINBLOCKWIDTH bins have any (possibly) non-empty bins, so they can be skipped over all at once during during traversals. The bits are NOT always cleared as soon as all bins in a block are empty, but instead only when all are noticed to be empty during traversal in malloc. */ #define BINBLOCKWIDTH 4 /* bins per block */ #define binblocks (bin_at(0)->size) /* bitvector of nonempty blocks */ /* bin<->block macros */ #define idx2binblock(ix) ((unsigned)1 << (ix / BINBLOCKWIDTH)) #define mark_binblock(ii) (binblocks |= idx2binblock(ii)) #define clear_binblock(ii) (binblocks &= ~(idx2binblock(ii))) /* Other static bookkeeping data */ /* variables holding tunable values */ static unsigned long trim_threshold = DEFAULT_TRIM_THRESHOLD; static unsigned long top_pad = DEFAULT_TOP_PAD; /* The first value returned from sbrk */ static char* sbrk_base = (char*)(-1); /* The maximum memory obtained from system via sbrk */ static unsigned long max_sbrked_mem = 0; /* The maximum via either sbrk or mmap */ static unsigned long max_total_mem = 0; /* internal working copy of mallinfo */ static struct mallinfo current_mallinfo = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }; /* The total memory obtained from system via sbrk */ #define sbrked_mem (current_mallinfo.arena) /* Debugging support */ /* These routines make a number of assertions about the states of data structures that should be true at all times. If any are not true, it's very likely that a user program has somehow trashed memory. (It's also possible that there is a coding error in malloc. In which case, please report it!) */ static void do_check_chunk(mchunkptr p) { INTERNAL_SIZE_T sz = p->size & ~PREV_INUSE; /* Check for legal address ... */ ASSERT((char*)p >= sbrk_base); if (p != top) ASSERT((char*)p + sz <= (char*)top); else ASSERT((char*)p + sz <= sbrk_base + sbrked_mem); } static void do_check_free_chunk(mchunkptr p) { INTERNAL_SIZE_T sz = p->size & ~PREV_INUSE; mchunkptr next = chunk_at_offset(p, sz); do_check_chunk(p); /* Check whether it claims to be free ... */ ASSERT(!inuse(p)); /* Unless a special marker, must have OK fields */ if ((long)sz >= (long)MINSIZE) { ASSERT((sz & MALLOC_ALIGN_MASK) == 0); ASSERT(aligned_OK(chunk2mem(p))); /* ... matching footer field */ ASSERT(next->prev_size == sz); /* ... and is fully consolidated */ ASSERT(prev_inuse(p)); ASSERT (next == top || inuse(next)); /* ... and has minimally sane links */ ASSERT(p->fd->bk == p); ASSERT(p->bk->fd == p); } else /* markers are always of size SIZE_SZ */ ASSERT(sz == SIZE_SZ); } static void do_check_inuse_chunk(mchunkptr p) { mchunkptr next = next_chunk(p); do_check_chunk(p); /* Check whether it claims to be in use ... */ ASSERT(inuse(p)); /* ... and is surrounded by OK chunks. Since more things can be checked with free chunks than inuse ones, if an inuse chunk borders them and debug is on, it's worth doing them. */ if (!prev_inuse(p)) { mchunkptr prv = prev_chunk(p); ASSERT(next_chunk(prv) == p); do_check_free_chunk(prv); } if (next == top) { ASSERT(prev_inuse(next)); ASSERT(chunksize(next) >= MINSIZE); } else if (!inuse(next)) do_check_free_chunk(next); } static void do_check_malloced_chunk(mchunkptr p, INTERNAL_SIZE_T s) { INTERNAL_SIZE_T sz = p->size & ~PREV_INUSE; long room = sz - s; do_check_inuse_chunk(p); /* Legal size ... */ ASSERT((long)sz >= (long)MINSIZE); ASSERT((sz & MALLOC_ALIGN_MASK) == 0); ASSERT(room >= 0); ASSERT(room < (long)MINSIZE); /* ... and alignment */ ASSERT(aligned_OK(chunk2mem(p))); /* ... and was allocated at front of an available chunk */ ASSERT(prev_inuse(p)); } #define check_free_chunk(P) do_check_free_chunk(P) #define check_inuse_chunk(P) do_check_inuse_chunk(P) #define check_chunk(P) do_check_chunk(P) #define check_malloced_chunk(P,N) do_check_malloced_chunk(P,N) /* Macro-based internal utilities */ /* Linking chunks in bin lists. Call these only with variables, not arbitrary expressions, as arguments. */ /* Place chunk p of size s in its bin, in size order, putting it ahead of others of same size. */ #define frontlink(P, S, IDX, BK, FD) \ { \ if (S < MAX_SMALLBIN_SIZE) \ { \ IDX = smallbin_index(S); \ mark_binblock(IDX); \ BK = bin_at(IDX); \ FD = BK->fd; \ P->bk = BK; \ P->fd = FD; \ FD->bk = BK->fd = P; \ } \ else \ { \ IDX = bin_index(S); \ BK = bin_at(IDX); \ FD = BK->fd; \ if (FD == BK) mark_binblock(IDX); \ else \ { \ while (FD != BK && S < chunksize(FD)) FD = FD->fd; \ BK = FD->bk; \ } \ P->bk = BK; \ P->fd = FD; \ FD->bk = BK->fd = P; \ } \ } /* take a chunk off a list */ #define unlink(P, BK, FD) \ { \ BK = P->bk; \ FD = P->fd; \ FD->bk = BK; \ BK->fd = FD; \ } \ /* Place p as the last remainder */ #define link_last_remainder(P) \ { \ last_remainder->fd = last_remainder->bk = P; \ P->fd = P->bk = last_remainder; \ } /* Clear the last_remainder bin */ #define clear_last_remainder \ (last_remainder->fd = last_remainder->bk = last_remainder) /* Extend the top-most chunk by obtaining memory from system. Main interface to sbrk (but see also malloc_trim). */ static void malloc_extend_top(INTERNAL_SIZE_T nb) { char* brk; /* return value from sbrk */ INTERNAL_SIZE_T front_misalign; /* unusable bytes at front of sbrked space */ INTERNAL_SIZE_T correction; /* bytes for 2nd sbrk call */ char* new_brk; /* return of 2nd sbrk call */ INTERNAL_SIZE_T top_size; /* new size of top chunk */ mchunkptr old_top = top; /* Record state of old top */ INTERNAL_SIZE_T old_top_size = chunksize(old_top); char* old_end = (char*)(chunk_at_offset(old_top, old_top_size)); /* Pad request with top_pad plus minimal overhead */ INTERNAL_SIZE_T sbrk_size = nb + top_pad + MINSIZE; unsigned long pagesz = malloc_getpagesize; /* If not the first time through, round to preserve page boundary */ /* Otherwise, we need to correct to a page size below anyway. */ /* (We also correct below if an intervening foreign sbrk call.) */ if (sbrk_base != (char*)(-1)) sbrk_size = (sbrk_size + (pagesz - 1)) & ~(pagesz - 1); brk = (char*)(MORECORE (sbrk_size)); /* Fail if sbrk failed or if a foreign sbrk call killed our space */ if (brk == (char*)(MORECORE_FAILURE) || (brk < old_end && old_top != initial_top)) { dbg_printf(" extend-top failed brk %x old_end %x old_top %x init_top %x sbrked_mem %x\n", brk,old_end,old_top,initial_top, sbrked_mem ); return; } sbrked_mem += sbrk_size; if (brk == old_end) /* can just add bytes to current top */ { top_size = sbrk_size + old_top_size; set_head(top, top_size | PREV_INUSE); } else { if (sbrk_base == (char*)(-1)) /* First time through. Record base */ sbrk_base = brk; else /* Someone else called sbrk(). Count those bytes as sbrked_mem. */ sbrked_mem += brk - (char*)old_end; /* Guarantee alignment of first new chunk made from this space */ front_misalign = (unsigned long)chunk2mem(brk) & MALLOC_ALIGN_MASK; if (front_misalign > 0) { correction = (MALLOC_ALIGNMENT) - front_misalign; brk += correction; } else correction = 0; /* Guarantee the next brk will be at a page boundary */ correction += pagesz - ((unsigned long)(brk + sbrk_size) & (pagesz - 1)); /* Allocate correction */ new_brk = (char*)(MORECORE (correction)); if (new_brk == (char*)(MORECORE_FAILURE)){ dbg_printf("new_brk failed correction %x \n",correction); return; } sbrked_mem += correction; top = (mchunkptr)brk; top_size = new_brk - brk + correction; set_head(top, top_size | PREV_INUSE); if (old_top != initial_top) { /* There must have been an intervening foreign sbrk call. */ /* A double fencepost is necessary to prevent consolidation */ /* If not enough space to do this, then user did something very wrong */ if (old_top_size < MINSIZE) { set_head(top, PREV_INUSE); /* will force null return from malloc */ dbg_printf(" extend failed old_top %x != initial_top %x old_top_size %x \n", old_top,initial_top,old_top_size); return; } /* Also keep size a multiple of MALLOC_ALIGNMENT */ old_top_size = (old_top_size - 3*SIZE_SZ) & ~MALLOC_ALIGN_MASK; chunk_at_offset(old_top, old_top_size )->size = SIZE_SZ|PREV_INUSE; chunk_at_offset(old_top, old_top_size + SIZE_SZ)->size = SIZE_SZ|PREV_INUSE; set_head_size(old_top, old_top_size); /* If possible, release the rest. */ if (old_top_size >= MINSIZE) { fREe(chunk2mem(old_top)); } } } if ((unsigned long)sbrked_mem > (unsigned long)max_sbrked_mem) max_sbrked_mem = sbrked_mem; /* We always land on a page boundary */ ASSERT(((unsigned long)((char*)top + top_size) & (pagesz - 1)) == 0); } /* Main public routines */ /* Malloc Algorthim: The requested size is first converted into a usable form, `nb'. This currently means to add 4 bytes overhead plus possibly more to obtain 8-byte alignment and/or to obtain a size of at least MINSIZE (currently 16 bytes), the smallest allocatable size. (All fits are considered `exact' if they are within MINSIZE bytes.) From there, the first successful of the following steps is taken: 1. The bin corresponding to the request size is scanned, and if a chunk of exactly the right size is found, it is taken. 2. The most recently remaindered chunk is used if it is big enough. This is a form of (roving) first fit, used only in the absence of exact fits. Runs of consecutive requests use the remainder of the chunk used for the previous such request whenever possible. This limited use of a first-fit style allocation strategy tends to give contiguous chunks coextensive lifetimes, which improves locality and can reduce fragmentation in the long run. 3. Other bins are scanned in increasing size order, using a chunk big enough to fulfill the request, and splitting off any remainder. This search is strictly by best-fit; i.e., the smallest (with ties going to approximately the least recently used) chunk that fits is selected. 4. If large enough, the chunk bordering the end of memory (`top') is split off. (This use of `top' is in accord with the best-fit search rule. In effect, `top' is treated as larger (and thus less well fitting) than any other available chunk since it can be extended to be as large as necessary (up to system limitations). 5. If the request size meets the mmap threshold and the system supports mmap, and there are few enough currently allocated mmapped regions, and a call to mmap succeeds, the request is allocated via direct memory mapping. 6. Otherwise, the top of memory is extended by obtaining more space from the system (normally using sbrk, but definable to anything else via the MORECORE macro). Memory is gathered from the system (in system page-sized units) in a way that allows chunks obtained across different sbrk calls to be consolidated, but does not require contiguous memory. Thus, it should be safe to intersperse mallocs with other sbrk calls. All allocations are made from the the `lowest' part of any found chunk. (The implementation invariant is that prev_inuse is always true of any allocated chunk; i.e., that each allocated chunk borders either a previously allocated and still in-use chunk, or the base of its memory arena.) */ Void_t* mALLoc(size_t bytes) { mchunkptr victim; /* inspected/selected chunk */ INTERNAL_SIZE_T victim_size; /* its size */ int idx; /* index for bin traversal */ mbinptr bin; /* associated bin */ mchunkptr remainder; /* remainder from a split */ long remainder_size; /* its size */ int remainder_index; /* its bin index */ unsigned long block; /* block traverser bit */ int startidx; /* first bin of a traversed block */ mchunkptr fwd; /* misc temp for linking */ mchunkptr bck; /* misc temp for linking */ mbinptr q; /* misc temp */ INTERNAL_SIZE_T nb; nb = request2size(bytes ); /* padded request size; */ semTake(dl_mem_sid,WAIT_FOREVER); /* Check for exact match in a bin */ if (is_small_request(nb)) /* Faster version for small requests */ { idx = smallbin_index(nb); /* No traversal or size check necessary for small bins. */ q = bin_at(idx); victim = last(q); /* Also scan the next one, since it would have a remainder < MINSIZE */ if (victim == q) { q = next_bin(q); victim = last(q); } if (victim != q) { victim_size = chunksize(victim); unlink(victim, bck, fwd); set_inuse_bit_at_offset(victim, victim_size); check_malloced_chunk(victim, nb); cumblocks ++; cumbytes += nb; semGive(dl_mem_sid); return chunk2mem(victim); } idx += 2; /* Set for bin scan below. We've already scanned 2 bins. */ } else { idx = bin_index(nb); bin = bin_at(idx); for (victim = last(bin); victim != bin; victim = victim->bk) { victim_size = chunksize(victim); remainder_size = victim_size - nb; if (remainder_size >= (long)MINSIZE) /* too big */ { --idx; /* adjust to rescan below after checking last remainder */ break; } else if (remainder_size >= 0) /* exact fit */ { unlink(victim, bck, fwd); set_inuse_bit_at_offset(victim, victim_size); check_malloced_chunk(victim, nb); cumblocks ++; cumbytes += nb; semGive(dl_mem_sid); return chunk2mem(victim); } } ++idx; } /* Try to use the last split-off remainder */ if ( (victim = last_remainder->fd) != last_remainder) { victim_size = chunksize(victim); remainder_size = victim_size - nb; if (remainder_size >= (long)MINSIZE) /* re-split */ { remainder = chunk_at_offset(victim, nb); set_head(victim, nb | PREV_INUSE); link_last_remainder(remainder); set_head(remainder, remainder_size | PREV_INUSE); set_foot(remainder, remainder_size); check_malloced_chunk(victim, nb); cumblocks ++; cumbytes += nb; semGive(dl_mem_sid); return chunk2mem(victim); } clear_last_remainder; if (remainder_size >= 0) /* exhaust */ { set_inuse_bit_at_offset(victim, victim_size); check_malloced_chunk(victim, nb); semGive(dl_mem_sid); cumblocks ++; cumbytes += nb; return chunk2mem(victim); } /* Else place in bin */ frontlink(victim, victim_size, remainder_index, bck, fwd); } /* If there are any possibly nonempty big-enough blocks, search for best fitting chunk by scanning bins in blockwidth units. */ if ( (block = idx2binblock(idx)) <= binblocks) { /* Get to the first marked block */ if ( (block & binblocks) == 0) { /* force to an even block boundary */ idx = (idx & ~(BINBLOCKWIDTH - 1)) + BINBLOCKWIDTH; block <<= 1; while ((block & binblocks) == 0) { idx += BINBLOCKWIDTH; block <<= 1; } } /* For each possibly nonempty block ... */ for (;;) { startidx = idx; /* (track incomplete blocks) */ q = bin = bin_at(idx); /* For each bin in this block ... */ do { /* Find and use first big enough chunk ... */ for (victim = last(bin); victim != bin; victim = victim->bk) { victim_size = chunksize(victim); remainder_size = victim_size - nb; if (remainder_size >= (long)MINSIZE) /* split */ { remainder = chunk_at_offset(victim, nb); set_head(victim, nb | PREV_INUSE); unlink(victim, bck, fwd); link_last_remainder(remainder); set_head(remainder, remainder_size | PREV_INUSE); set_foot(remainder, remainder_size); check_malloced_chunk(victim, nb); cumblocks ++; cumbytes += nb; semGive(dl_mem_sid); return chunk2mem(victim); } else if (remainder_size >= 0) /* take */ { set_inuse_bit_at_offset(victim, victim_size); unlink(victim, bck, fwd); check_malloced_chunk(victim, nb); cumblocks ++; cumbytes += nb; semGive(dl_mem_sid); return chunk2mem(victim); } } bin = next_bin(bin); } while ((++idx & (BINBLOCKWIDTH - 1)) != 0); /* Clear out the block bit. */ do /* Possibly backtrack to try to clear a partial block */ { if ((startidx & (BINBLOCKWIDTH - 1)) == 0) { binblocks &= ~block; break; } --startidx; q = prev_bin(q); } while (first(q) == q); /* Get to the next possibly nonempty block */ if ( (block <<= 1) <= binblocks && (block != 0) ) { while ((block & binblocks) == 0) { idx += BINBLOCKWIDTH; block <<= 1; } } else break; } } /* Try to use top chunk */ /* Require that there be a remainder, ensuring top always exists */ if ( (remainder_size = chunksize(top) - nb) < (long)MINSIZE) { /* Try to extend */ malloc_extend_top(nb); if ( (remainder_size = chunksize(top) - nb) < (long)MINSIZE) { dbg_printf(" malloc failed %d\n",bytes); semGive(dl_mem_sid); return 0; /* propagate failure */ } } victim = top; set_head(victim, nb | PREV_INUSE); top = chunk_at_offset(victim, nb); set_head(top, remainder_size | PREV_INUSE); check_malloced_chunk(victim, nb); cumblocks ++; cumbytes += nb; semGive(dl_mem_sid); return chunk2mem(victim); } /* free() algorithm : cases: 1. free(0) has no effect. 2. If the chunk was allocated via mmap, it is release via munmap(). 3. If a returned chunk borders the current high end of memory, it is consolidated into the top, and if the total unused topmost memory exceeds the trim threshold, malloc_trim is called. 4. Other chunks are consolidated as they arrive, and placed in corresponding bins. (This includes the case of consolidating with the current `last_remainder'). */ void fREe(Void_t* mem) { mchunkptr p; /* chunk corresponding to mem */ INTERNAL_SIZE_T hd; /* its head field */ INTERNAL_SIZE_T sz; /* its size */ int idx; /* its bin index */ mchunkptr next; /* next contiguous chunk */ INTERNAL_SIZE_T nextsz; /* its size */ INTERNAL_SIZE_T prevsz; /* size of previous contiguous chunk */ mchunkptr bck; /* misc temp for linking */ mchunkptr fwd; /* misc temp for linking */ int islr; /* track whether merging with last_remainder */ if (mem == 0) /* free(0) has no effect */ return; p = mem2chunk(mem); hd = p->size; check_inuse_chunk(p); sz = hd & ~PREV_INUSE; next = chunk_at_offset(p, sz); nextsz = chunksize(next); semTake(dl_mem_sid,WAIT_FOREVER); if (next == top) /* merge with top */ { sz += nextsz; if (!(hd & PREV_INUSE)) /* consolidate backward */ { prevsz = p->prev_size; p = chunk_at_offset(p, -prevsz); sz += prevsz; unlink(p, bck, fwd); } set_head(p, sz | PREV_INUSE); top = p; if ((unsigned long)(sz) >= (unsigned long)trim_threshold) malloc_trim(top_pad); semGive(dl_mem_sid); return; } set_head(next, nextsz); /* clear inuse bit */ islr = 0; if (!(hd & PREV_INUSE)) /* consolidate backward */ { prevsz = p->prev_size; p = chunk_at_offset(p, -prevsz); sz += prevsz; if (p->fd == last_remainder) /* keep as last_remainder */ islr = 1; else unlink(p, bck, fwd); } if (!(inuse_bit_at_offset(next, nextsz))) /* consolidate forward */ { sz += nextsz; if (!islr && next->fd == last_remainder) /* re-insert last_remainder */ { islr = 1; link_last_remainder(p); } else unlink(next, bck, fwd); } set_head(p, sz | PREV_INUSE); set_foot(p, sz); if (!islr) frontlink(p, sz, idx, bck, fwd); semGive(dl_mem_sid); } /* Realloc algorithm: Chunks that were obtained via mmap cannot be extended or shrunk unless HAVE_MREMAP is defined, in which case mremap is used. Otherwise, if their reallocation is for additional space, they are copied. If for less, they are just left alone. Otherwise, if the reallocation is for additional space, and the chunk can be extended, it is, else a malloc-copy-free sequence is taken. There are several different ways that a chunk could be extended. All are tried: * Extending forward into following adjacent free chunk. * Shifting backwards, joining preceding adjacent space * Both shifting backwards and extending forward. * Extending into newly sbrked space Unless the #define REALLOC_ZERO_BYTES_FREES is set, realloc with a size argument of zero (re)allocates a minimum-sized chunk. If the reallocation is for less space, and the new request is for a `small' (<512 bytes) size, then the newly unused space is lopped off and freed. The old unix realloc convention of allowing the last-free'd chunk to be used as an argument to realloc is no longer supported. I don't know of any programs still relying on this feature, and allowing it would also allow too many other incorrect usages of realloc to be sensible. */ Void_t* reALLoc(Void_t* oldmem, size_t bytes) { INTERNAL_SIZE_T nb; /* padded request size */ mchunkptr oldp; /* chunk corresponding to oldmem */ INTERNAL_SIZE_T oldsize; /* its size */ mchunkptr newp; /* chunk to return */ INTERNAL_SIZE_T newsize; /* its size */ Void_t* newmem; /* corresponding user mem */ mchunkptr next; /* next contiguous chunk after oldp */ INTERNAL_SIZE_T nextsize; /* its size */ mchunkptr prev; /* previous contiguous chunk before oldp */ INTERNAL_SIZE_T prevsize; /* its size */ mchunkptr remainder; /* holds split off extra space from newp */ INTERNAL_SIZE_T remainder_size; /* its size */ mchunkptr bck; /* misc temp for linking */ mchunkptr fwd; /* misc temp for linking */ if (bytes == 0) { fREe(oldmem); return 0; } /* realloc of null is supposed to be same as malloc */ if (oldmem == 0) { return mALLoc(bytes); } newp = oldp = mem2chunk(oldmem); newsize = oldsize = chunksize(oldp); nb = request2size(bytes); check_inuse_chunk(oldp); if ((long)(oldsize) < (long)(nb)) { /* Try expanding forward */ semTake(dl_mem_sid,WAIT_FOREVER); next = chunk_at_offset(oldp, oldsize); if (next == top || !inuse(next)) { nextsize = chunksize(next); /* Forward into top only if a remainder */ if (next == top) { if ((long)(nextsize + newsize) >= (long)(nb + MINSIZE)) { newsize += nextsize; top = chunk_at_offset(oldp, nb); set_head(top, (newsize - nb) | PREV_INUSE); set_head_size(oldp, nb); semGive(dl_mem_sid); return chunk2mem(oldp); } } /* Forward into next chunk */ else if (((long)(nextsize + newsize) >= (long)(nb))) { unlink(next, bck, fwd); newsize += nextsize; goto split; } } else { next = 0; nextsize = 0; } /* Try shifting backwards. */ if (!prev_inuse(oldp)) { prev = prev_chunk(oldp); prevsize = chunksize(prev); /* try forward + backward first to save a later consolidation */ if (next != 0) { /* into top */ if (next == top) { if ((long)(nextsize + prevsize + newsize) >= (long)(nb + MINSIZE)) { unlink(prev, bck, fwd); newp = prev; newsize += prevsize + nextsize; newmem = chunk2mem(newp); bcopy(oldmem,newmem, oldsize - SIZE_SZ); top = chunk_at_offset(newp, nb); set_head(top, (newsize - nb) | PREV_INUSE); set_head_size(newp, nb); semGive(dl_mem_sid); return newmem; } } /* into next chunk */ else if (((long)(nextsize + prevsize + newsize) >= (long)(nb))) { unlink(next, bck, fwd); unlink(prev, bck, fwd); newp = prev; newsize += nextsize + prevsize; newmem = chunk2mem(newp); bcopy( oldmem,newmem, oldsize - SIZE_SZ); goto split; } } /* backward only */ if (prev != 0 && (long)(prevsize + newsize) >= (long)nb) { unlink(prev, bck, fwd); newp = prev; newsize += prevsize; newmem = chunk2mem(newp); bcopy( oldmem,newmem, oldsize - SIZE_SZ); goto split; } } /* Must allocate */ semGive(dl_mem_sid); newmem = mALLoc (bytes); if (newmem == 0) /* propagate failure */ { return 0; } /* Avoid copy if newp is next chunk after oldp. */ /* (This can only happen when new chunk is sbrk'ed.) */ if ( (newp = mem2chunk(newmem)) == next_chunk(oldp)) { newsize += chunksize(newp); newp = oldp; goto split; } /* Otherwise copy, free, and exit */ bcopy(oldmem,newmem, oldsize - SIZE_SZ); fREe(oldmem); return newmem; } split: /* split off extra room in old or expanded chunk */ if (newsize - nb >= MINSIZE) /* split off remainder */ { remainder = chunk_at_offset(newp, nb); remainder_size = newsize - nb; set_head_size(newp, nb); set_head(remainder, remainder_size | PREV_INUSE); set_inuse_bit_at_offset(remainder, remainder_size); fREe(chunk2mem(remainder)); /* let free() deal with it */ } else { set_head_size(newp, newsize); set_inuse_bit_at_offset(newp, newsize); } check_inuse_chunk(newp); semGive(dl_mem_sid); return chunk2mem(newp); } /* memalign algorithm: memalign requests more than enough space from malloc, finds a spot within that chunk that meets the alignment request, and then possibly frees the leading and trailing space. The alignment argument must be a power of two. This property is not checked by memalign, so misuse may result in random runtime errors. 8-byte alignment is guaranteed by normal malloc calls, so don't bother calling memalign with an argument of 8 or less. Overreliance on memalign is a sure way to fragment space. */ Void_t* mEMALIGn(size_t alignment, size_t bytes) { INTERNAL_SIZE_T nb; /* padded request size */ char* m; /* memory returned by malloc call */ mchunkptr p; /* corresponding chunk */ char* brk; /* alignment point within p */ mchunkptr newp; /* chunk to return */ INTERNAL_SIZE_T newsize; /* its size */ INTERNAL_SIZE_T leadsize; /* leading space befor alignment point */ mchunkptr remainder; /* spare room at end to split off */ long remainder_size; /* its size */ /* If need less alignment than we give anyway, just relay to malloc */ dbg_printf(" memalign %x %x \n",alignment,bytes); if (alignment <= MALLOC_ALIGNMENT) { return mALLoc(bytes); } /* Otherwise, ensure that it is at least a minimum chunk size */ if (alignment < MINSIZE) alignment = MINSIZE; /* Call malloc with worst case padding to hit alignment. */ nb = request2size(bytes); m = (char*)(mALLoc(nb + alignment + MINSIZE)); if (m == 0) return 0; /* propagate failure */ p = mem2chunk(m); if ((((unsigned long)(m)) % alignment) == 0) /* aligned */ { } else /* misaligned */ { /* Find an aligned spot inside chunk. Since we need to give back leading space in a chunk of at least MINSIZE, if the first calculation places us at a spot with less than MINSIZE leader, we can move to the next aligned spot -- we've allocated enough total room so that this is always possible. */ brk = (char*)mem2chunk(((unsigned long)(m + alignment - 1)) & -alignment); if ((long)(brk - (char*)(p)) < MINSIZE) brk = brk + alignment; newp = (mchunkptr)brk; leadsize = brk - (char*)(p); newsize = chunksize(p) - leadsize; /* give back leader, use the rest */ set_head(newp, newsize | PREV_INUSE); set_inuse_bit_at_offset(newp, newsize); set_head_size(p, leadsize); fREe(chunk2mem(p)); p = newp; ASSERT (newsize >= nb && (((unsigned long)(chunk2mem(p))) % alignment) == 0); } /* Also give back spare room at the end */ remainder_size = chunksize(p) - nb; if (remainder_size >= (long)MINSIZE) { remainder = chunk_at_offset(p, nb); set_head(remainder, remainder_size | PREV_INUSE); set_head_size(p, nb); fREe(chunk2mem(remainder)); } check_inuse_chunk(p); return chunk2mem(p); } /* valloc just invokes memalign with alignment argument equal to the page size of the system (or as near to this as can be figured out from all the includes/defines above.) */ Void_t* vALLoc(size_t bytes) { return( mEMALIGn (malloc_getpagesize, bytes)); } /* pvalloc just invokes valloc for the nearest pagesize that will accommodate request */ Void_t* cALLoc(size_t n, size_t elem_size) { INTERNAL_SIZE_T sz = n * elem_size; Void_t* mem; mem = mALLoc (sz); if (mem == 0) { dbg_printf(" calloc failed \n"); return 0; } else { bzero(mem, sz); return mem; } } /* Malloc_trim gives memory back to the system (via negative arguments to sbrk) if there is unused memory at the `high' end of the malloc pool. You can call this after freeing large blocks of memory to potentially reduce the system-level memory requirements of a program. However, it cannot guarantee to reduce memory. Under some allocation patterns, some large free blocks of memory will be locked between two used chunks, so they cannot be given back to the system. The `pad' argument to malloc_trim represents the amount of free trailing space to leave untrimmed. If this argument is zero, only the minimum amount of memory to maintain internal data structures will be left (one page or less). Non-zero arguments can be supplied to maintain enough trailing space to service future expected allocations without having to re-obtain memory from the system. Malloc_trim returns 1 if it actually released any memory, else 0. */ int malloc_trim(size_t pad) { long top_size; /* Amount of top-most memory */ long extra; /* Amount to release */ char* current_brk; /* address returned by pre-check sbrk call */ char* new_brk; /* address returned by negative sbrk call */ unsigned long pagesz = malloc_getpagesize; top_size = chunksize(top); extra = ((top_size - pad - MINSIZE + (pagesz-1)) / pagesz - 1) * pagesz; if (extra < (long)pagesz) /* Not enough memory to release */ return 0; else { /* Test to make sure no one else called sbrk */ current_brk = (char*)(MORECORE (0)); if (current_brk != (char*)(top) + top_size) return 0; /* Apparently we don't own memory; must fail */ else { new_brk = (char*)(MORECORE (-extra)); if (new_brk == (char*)(MORECORE_FAILURE)) /* sbrk failed? */ { /* Try to figure out what we have */ current_brk = (char*)(MORECORE (0)); top_size = current_brk - (char*)top; if (top_size >= (long)MINSIZE) /* if not, we are very very dead! */ { sbrked_mem = current_brk - sbrk_base; set_head(top, top_size | PREV_INUSE); } check_chunk(top); return 0; } else { /* Success. Adjust top accordingly. */ set_head(top, (top_size - extra) | PREV_INUSE); sbrked_mem -= extra; check_chunk(top); return 1; } } } } /* malloc_usable_size: This routine tells you how many bytes you can actually use in an allocated chunk, which may be more than you requested (although often not). You can use this many bytes without worrying about overwriting other allocated objects. Not a particularly great programming practice, but still sometimes useful. */ size_t malloc_usable_size(Void_t* mem) { mchunkptr p; if (mem == 0) return 0; else { p = mem2chunk(mem); return chunksize(p) - 2*SIZE_SZ; } } /* See malloc_stats for modes. */ static void malloc_update_mallinfo( int mode ) { int i; mbinptr b; mchunkptr p; mchunkptr q; INTERNAL_SIZE_T avail = chunksize(top); int navail = ((long)(avail) >= (long)MINSIZE)? 1 : 0; for (i = 1; i < NAV; ++i) { b = bin_at(i); for (p = last(b); p != b; p = p->bk) { check_free_chunk(p); for (q = next_chunk(p); q < top && inuse(q) && (long)(chunksize(q)) >= (long)MINSIZE; q = next_chunk(q)) check_inuse_chunk(q); avail += chunksize(p); if (mode) dbg_printf(" addr %x size %d \n", p,chunksize(p)); navail++; } } current_mallinfo.ordblks = navail; current_mallinfo.uordblks = sbrked_mem - avail; current_mallinfo.fordblks = avail; current_mallinfo.keepcost = chunksize(top); } /* malloc_stats: Prints on stderr the amount of space obtain from the system (both via sbrk and mmap), the maximum amount (which may be more than current if malloc_trim and/or munmap got called), the maximum number of simultaneous mmap regions used, and the current number of bytes allocated via malloc (or realloc, etc) but not yet freed. (Note that this is the number of bytes allocated, not the number requested. It will be larger than the number requested because of alignment and bookkeeping overhead.) mode = 0, summary 1, free list + summary. */ void dl_malloc_stats( int mode ) { malloc_update_mallinfo(mode); #ifndef VXWORKS fprintf(stderr, "max system bytes = %10u\n", (unsigned int)(max_total_mem)); fprintf(stderr, "system bytes = %10u\n", (unsigned int)(sbrked_mem )); fprintf(stderr, "in use bytes = %10u\n", (unsigned int)(current_mallinfo.uordblks )); #else printf("max system bytes = %10u\n", (unsigned int)(max_total_mem)); printf("system bytes = %10u\n", (unsigned int)(sbrked_mem )); printf("in use bytes = %10u\n", (unsigned int)(current_mallinfo.uordblks)); #endif } int dl_get_largest() { int i,used = 0; mbinptr b; mchunkptr p; mchunkptr q; int larg = 0,size; INTERNAL_SIZE_T avail = chunksize(top); int navail = ((long)(avail) >= (long)MINSIZE)? 1 : 0; for (i = 1; i < NAV; ++i) { b = bin_at(i); for (p = last(b); p != b; p = p->bk) { check_free_chunk(p); for (q = next_chunk(p); q < top && inuse(q) && (long)(chunksize(q)) >= (long)MINSIZE; q = next_chunk(q)) { check_inuse_chunk(q); used ++; } size = chunksize(p); if (size > larg) larg = size; avail += size; navail++; } } return larg; } #endif /* USE_DL */ void *malloc(size_t bytes) { #ifdef USE_BSD if (bsd_malloc_initialized) { return bsd_malloc(bytes); } dbg_printf("bsd malloc not initialized yet\n"); #endif #ifdef USE_DL if (dl_malloc_initialized ) { return(mALLoc(bytes)); } dbg_printf("dl malloc not initialized yet\n"); #endif } void free(void* mem) { #ifdef USE_BSD if (bsd_malloc_initialized) { bsd_free(mem); return; } dbg_printf("bsd malloc not initialized yet\n"); #endif #ifdef USE_DL if (dl_malloc_initialized ) { fREe(mem); return; } dbg_printf("dl malloc not initialized yet\n "); #endif } void cfree(void* mem) { #ifdef USE_BSD if (bsd_malloc_initialized) { bsd_free(mem); return; } dbg_printf("bsd malloc not initialized yet\n"); #endif #ifdef USE_DL if (dl_malloc_initialized ) { fREe(mem); return; } dbg_printf("dl malloc not initialized yet\n "); #endif } void *calloc(size_t bytes, size_t elem_size) { unsigned int size = elem_size * bytes; #ifdef USE_BSD char *vp; if (bsd_malloc_initialized) { vp = (char *)bsd_malloc(size); bzero((char*)vp, size); return vp; } dbg_printf("bsd malloc not initialized yet\n"); #endif #ifdef USE_DL if (dl_malloc_initialized ) { return( cALLoc(bytes, elem_size)); } dbg_printf("dl malloc not initialized yet \n"); #endif } void *realloc(void * oldmem, size_t bytes) { #ifdef USE_BSD if (bsd_malloc_initialized && oldmem >= bsd_malloc_bottom && oldmem < bsd_malloc_top) return bsd_realloc(oldmem, bytes); #endif #ifdef USE_DL return ( reALLoc(oldmem, bytes)); #endif } void *memalign(size_t alignment, size_t bytes) { #ifdef USE_BSD void *vp; if (bsd_malloc_initialized) { vp = bsd_malloc(bytes + alignment); if (vp != 0) { vp = (char *)(((int)vp + alignment) & ~(alignment - 1)); return vp; } dbg_printf("bsd memalign, bad malloc\n"); return 0; } dbg_printf("bsd malloc not initialized yet\n"); #endif #ifdef USE_DL if (dl_malloc_initialized ) { return( mEMALIGn (alignment,bytes )); } dbg_printf("dl malloc not initialized yet \n"); #endif } void *valloc(size_t bytes) { return (memalign (VX_PAGE_SIZE, bytes)); /* Psuedo page size XXX */ } /* XXX HACK ALERT --- VxWorks 'emulation' stuff */ void *memSysPartId = 0; void *memPartClassId = 0; int memPartLibInit(char *p, unsigned int sz) { dbg_printf("memPartInit: sz %d\n",sz); #ifdef USE_BSD bsd_malloc_init(p, sz); #endif #ifdef USE_DL dl_malloc_init(p, sz); #endif } int memInit(char *p, unsigned int sz) { dbg_printf("memInit: sz %d\n",sz); return memPartLibInit(p, sz); } int memShowInit() { } void memShow(int mode) { #ifdef USE_BSD bsd_mstats(mode); #endif #ifdef USE_DL dl_malloc_stats(mode); #endif } int memAddToPool(void *p, void *pp, unsigned int sz) { dbg_printf("memAddToPool called with sz %d\n",sz); return 0; } int memPartCreate(void *p, unsigned int sz) { return 1; } int memPartAlloc(void *p, unsigned int sz) { return(malloc(sz)); } int memPartFree(void *p, void *data) { free(p); return 0; }

View Details Posted at:11/28/2011 23:48:00 

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