2172 lines
72 KiB
C
2172 lines
72 KiB
C
/*
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This is a version (aka dlmalloc) of malloc/free/realloc written by
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Doug Lea and released to the public domain, as explained at
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http://creativecommons.org/licenses/publicdomain. Send questions,
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comments, complaints, performance data, etc to dl@cs.oswego.edu
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* Version 2.8.4 Wed May 27 09:56:23 2009 Doug Lea (dl at gee)
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Note: There may be an updated version of this malloc obtainable at
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ftp://gee.cs.oswego.edu/pub/misc/malloc.c
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Check before installing!
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* Quickstart
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This library is all in one file to simplify the most common usage:
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ftp it, compile it (-O3), and link it into another program. All of
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the compile-time options default to reasonable values for use on
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most platforms. You might later want to step through various
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compile-time and dynamic tuning options.
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For convenience, an include file for code using this malloc is at:
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ftp://gee.cs.oswego.edu/pub/misc/malloc-2.8.4.h
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You don't really need this .h file unless you call functions not
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defined in your system include files. The .h file contains only the
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excerpts from this file needed for using this malloc on ANSI C/C++
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systems, so long as you haven't changed compile-time options about
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naming and tuning parameters. If you do, then you can create your
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own malloc.h that does include all settings by cutting at the point
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indicated below. Note that you may already by default be using a C
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library containing a malloc that is based on some version of this
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malloc (for example in linux). You might still want to use the one
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in this file to customize settings or to avoid overheads associated
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with library versions.
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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struct malloc_chunk {
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size_t prev_foot; /* Size of previous chunk (if free). */
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size_t head; /* Size and inuse bits. */
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struct malloc_chunk* fd; /* double links -- used only if free. */
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struct malloc_chunk* bk;
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};
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typedef struct malloc_chunk mchunk;
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typedef struct malloc_chunk* mchunkptr;
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typedef struct malloc_chunk* sbinptr; /* The type of bins of chunks */
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typedef unsigned int bindex_t; /* Described below */
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typedef unsigned int binmap_t; /* Described below */
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typedef unsigned int flag_t; /* The type of various bit flag sets */
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/* ------------------- size_t and alignment properties -------------------- */
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/* The maximum possible size_t value has all bits set */
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#define MAX_SIZE_T (~(size_t)0)
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void *user_alloc(size_t size)
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{
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void *val;
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// __asm__("int3");
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__asm__ __volatile__(
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"int $0x40"
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:"=a"(val)
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:"a"(68),"b"(12),"c"(size));
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return val;
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}
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static inline
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int user_free(void *mem)
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{
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int val;
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// __asm__("int3");
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__asm__ __volatile__(
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"int $0x40"
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:"=a"(val)
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:"a"(68),"b"(13),"c"(mem));
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return val;
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}
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/* ------------------- size_t and alignment properties -------------------- */
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/* The byte and bit size of a size_t */
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#define SIZE_T_SIZE (sizeof(size_t))
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#define SIZE_T_BITSIZE (sizeof(size_t) << 3)
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/* Some constants coerced to size_t */
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/* Annoying but necessary to avoid errors on some platforms */
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#define SIZE_T_ZERO ((size_t)0)
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#define SIZE_T_ONE ((size_t)1)
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#define SIZE_T_TWO ((size_t)2)
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#define SIZE_T_FOUR ((size_t)4)
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#define TWO_SIZE_T_SIZES (SIZE_T_SIZE<<1)
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#define FOUR_SIZE_T_SIZES (SIZE_T_SIZE<<2)
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#define SIX_SIZE_T_SIZES (FOUR_SIZE_T_SIZES+TWO_SIZE_T_SIZES)
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#define HALF_MAX_SIZE_T (MAX_SIZE_T / 2U)
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#define USE_LOCK_BIT (2U)
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#define USE_MMAP_BIT (SIZE_T_ONE)
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#define USE_NONCONTIGUOUS_BIT (4U)
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/* segment bit set in create_mspace_with_base */
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#define EXTERN_BIT (8U)
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#define HAVE_MMAP 1
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#define CALL_MMAP(s) MMAP_DEFAULT(s)
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#define CALL_MUNMAP(a, s) MUNMAP_DEFAULT((a), (s))
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#define CALL_MREMAP(addr, osz, nsz, mv) MFAIL
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#define calloc_must_clear(p) (!is_mmapped(p))
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#define MALLOC_FAILURE_ACTION
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#define MAX_RELEASE_CHECK_RATE 4095
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#define NO_SEGMENT_TRAVERSAL 1
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#define MALLOC_ALIGNMENT ((size_t)8U)
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#define CHUNK_OVERHEAD (SIZE_T_SIZE)
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#define DEFAULT_GRANULARITY ((size_t)512U * (size_t)1024U)
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#define DEFAULT_MMAP_THRESHOLD ((size_t)1024U * (size_t)1024U)
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#define DEFAULT_TRIM_THRESHOLD ((size_t)2048U * (size_t)1024U)
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/* The bit mask value corresponding to MALLOC_ALIGNMENT */
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#define CHUNK_ALIGN_MASK (MALLOC_ALIGNMENT - SIZE_T_ONE)
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/* True if address a has acceptable alignment */
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#define is_aligned(A) (((size_t)((A)) & (CHUNK_ALIGN_MASK)) == 0)
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/* the number of bytes to offset an address to align it */
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#define align_offset(A)\
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((((size_t)(A) & CHUNK_ALIGN_MASK) == 0)? 0 :\
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((MALLOC_ALIGNMENT - ((size_t)(A) & CHUNK_ALIGN_MASK)) & CHUNK_ALIGN_MASK))
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#define MFAIL ((void*)(MAX_SIZE_T))
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#define CMFAIL ((char*)(MFAIL)) /* defined for convenience */
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/* For sys_alloc, enough padding to ensure can malloc request on success */
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#define SYS_ALLOC_PADDING (TOP_FOOT_SIZE + MALLOC_ALIGNMENT)
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/*
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TOP_FOOT_SIZE is padding at the end of a segment, including space
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that may be needed to place segment records and fenceposts when new
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noncontiguous segments are added.
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*/
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#define TOP_FOOT_SIZE\
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(align_offset(chunk2mem(0))+pad_request(sizeof(struct malloc_segment))+MIN_CHUNK_SIZE)
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/* ------------------- Chunks sizes and alignments ----------------------- */
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#define MCHUNK_SIZE (sizeof(mchunk))
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/* MMapped chunks need a second word of overhead ... */
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#define MMAP_CHUNK_OVERHEAD (TWO_SIZE_T_SIZES)
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/* ... and additional padding for fake next-chunk at foot */
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#define MMAP_FOOT_PAD (FOUR_SIZE_T_SIZES)
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/* The smallest size we can malloc is an aligned minimal chunk */
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#define MIN_CHUNK_SIZE\
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((MCHUNK_SIZE + CHUNK_ALIGN_MASK) & ~CHUNK_ALIGN_MASK)
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/* conversion from malloc headers to user pointers, and back */
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#define chunk2mem(p) ((void*)((char*)(p) + TWO_SIZE_T_SIZES))
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#define mem2chunk(mem) ((mchunkptr)((char*)(mem) - TWO_SIZE_T_SIZES))
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/* chunk associated with aligned address A */
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#define align_as_chunk(A) (mchunkptr)((A) + align_offset(chunk2mem(A)))
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/* Bounds on request (not chunk) sizes. */
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#define MAX_REQUEST ((-MIN_CHUNK_SIZE) << 2)
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#define MIN_REQUEST (MIN_CHUNK_SIZE - CHUNK_OVERHEAD - SIZE_T_ONE)
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/* pad request bytes into a usable size */
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#define pad_request(req) \
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(((req) + CHUNK_OVERHEAD + CHUNK_ALIGN_MASK) & ~CHUNK_ALIGN_MASK)
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/* pad request, checking for minimum (but not maximum) */
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#define request2size(req) \
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(((req) < MIN_REQUEST)? MIN_CHUNK_SIZE : pad_request(req))
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/* ------------------ Operations on head and foot fields ----------------- */
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/*
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The head field of a chunk is or'ed with PINUSE_BIT when previous
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adjacent chunk in use, and or'ed with CINUSE_BIT if this chunk is in
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use, unless mmapped, in which case both bits are cleared.
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FLAG4_BIT is not used by this malloc, but might be useful in extensions.
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*/
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#define PINUSE_BIT (SIZE_T_ONE)
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#define CINUSE_BIT (SIZE_T_TWO)
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#define FLAG4_BIT (SIZE_T_FOUR)
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#define INUSE_BITS (PINUSE_BIT|CINUSE_BIT)
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#define FLAG_BITS (PINUSE_BIT|CINUSE_BIT|FLAG4_BIT)
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/* Head value for fenceposts */
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#define FENCEPOST_HEAD (INUSE_BITS|SIZE_T_SIZE)
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/* extraction of fields from head words */
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#define cinuse(p) ((p)->head & CINUSE_BIT)
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#define pinuse(p) ((p)->head & PINUSE_BIT)
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#define is_inuse(p) (((p)->head & INUSE_BITS) != PINUSE_BIT)
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#define is_mmapped(p) (((p)->head & INUSE_BITS) == 0)
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#define chunksize(p) ((p)->head & ~(FLAG_BITS))
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#define clear_pinuse(p) ((p)->head &= ~PINUSE_BIT)
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/* Treat space at ptr +/- offset as a chunk */
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#define chunk_plus_offset(p, s) ((mchunkptr)(((char*)(p)) + (s)))
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#define chunk_minus_offset(p, s) ((mchunkptr)(((char*)(p)) - (s)))
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/* Ptr to next or previous physical malloc_chunk. */
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#define next_chunk(p) ((mchunkptr)( ((char*)(p)) + ((p)->head & ~FLAG_BITS)))
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#define prev_chunk(p) ((mchunkptr)( ((char*)(p)) - ((p)->prev_foot) ))
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/* extract next chunk's pinuse bit */
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#define next_pinuse(p) ((next_chunk(p)->head) & PINUSE_BIT)
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/* Set size, pinuse bit, and foot */
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#define set_size_and_pinuse_of_free_chunk(p, s)\
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((p)->head = (s|PINUSE_BIT), set_foot(p, s))
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/* Set size, pinuse bit, foot, and clear next pinuse */
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#define set_free_with_pinuse(p, s, n)\
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(clear_pinuse(n), set_size_and_pinuse_of_free_chunk(p, s))
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/* Get the internal overhead associated with chunk p */
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#define overhead_for(p)\
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(is_mmapped(p)? MMAP_CHUNK_OVERHEAD : CHUNK_OVERHEAD)
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struct malloc_tree_chunk {
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/* The first four fields must be compatible with malloc_chunk */
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size_t prev_foot;
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size_t head;
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struct malloc_tree_chunk* fd;
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struct malloc_tree_chunk* bk;
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struct malloc_tree_chunk* child[2];
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struct malloc_tree_chunk* parent;
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bindex_t index;
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};
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typedef struct malloc_tree_chunk tchunk;
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typedef struct malloc_tree_chunk* tchunkptr;
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typedef struct malloc_tree_chunk* tbinptr; /* The type of bins of trees */
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/* A little helper macro for trees */
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#define leftmost_child(t) ((t)->child[0] != 0? (t)->child[0] : (t)->child[1])
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struct malloc_segment {
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char* base; /* base address */
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size_t size; /* allocated size */
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struct malloc_segment* next; /* ptr to next segment */
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flag_t sflags; /* mmap and extern flag */
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};
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#define is_mmapped_segment(S) ((S)->sflags & USE_MMAP_BIT)
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#define is_extern_segment(S) ((S)->sflags & EXTERN_BIT)
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typedef struct malloc_segment msegment;
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typedef struct malloc_segment* msegmentptr;
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/* ---------------------------- malloc_state ----------------------------- */
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/*
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A malloc_state holds all of the bookkeeping for a space.
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The main fields are:
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Top
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The topmost chunk of the currently active segment. Its size is
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cached in topsize. The actual size of topmost space is
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topsize+TOP_FOOT_SIZE, which includes space reserved for adding
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fenceposts and segment records if necessary when getting more
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space from the system. The size at which to autotrim top is
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cached from mparams in trim_check, except that it is disabled if
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an autotrim fails.
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Designated victim (dv)
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This is the preferred chunk for servicing small requests that
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don't have exact fits. It is normally the chunk split off most
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recently to service another small request. Its size is cached in
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dvsize. The link fields of this chunk are not maintained since it
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is not kept in a bin.
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SmallBins
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An array of bin headers for free chunks. These bins hold chunks
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with sizes less than MIN_LARGE_SIZE bytes. Each bin contains
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chunks of all the same size, spaced 8 bytes apart. To simplify
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use in double-linked lists, each bin header acts as a malloc_chunk
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pointing to the real first node, if it exists (else pointing to
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itself). This avoids special-casing for headers. But to avoid
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waste, we allocate only the fd/bk pointers of bins, and then use
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repositioning tricks to treat these as the fields of a chunk.
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TreeBins
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Treebins are pointers to the roots of trees holding a range of
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sizes. There are 2 equally spaced treebins for each power of two
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from TREE_SHIFT to TREE_SHIFT+16. The last bin holds anything
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larger.
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Bin maps
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There is one bit map for small bins ("smallmap") and one for
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treebins ("treemap). Each bin sets its bit when non-empty, and
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clears the bit when empty. Bit operations are then used to avoid
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bin-by-bin searching -- nearly all "search" is done without ever
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looking at bins that won't be selected. The bit maps
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conservatively use 32 bits per map word, even if on 64bit system.
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For a good description of some of the bit-based techniques used
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here, see Henry S. Warren Jr's book "Hacker's Delight" (and
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supplement at http://hackersdelight.org/). Many of these are
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intended to reduce the branchiness of paths through malloc etc, as
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well as to reduce the number of memory locations read or written.
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Segments
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A list of segments headed by an embedded malloc_segment record
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representing the initial space.
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Address check support
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The least_addr field is the least address ever obtained from
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MORECORE or MMAP. Attempted frees and reallocs of any address less
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than this are trapped (unless INSECURE is defined).
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Magic tag
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A cross-check field that should always hold same value as mparams.magic.
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Flags
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Bits recording whether to use MMAP, locks, or contiguous MORECORE
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Statistics
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Each space keeps track of current and maximum system memory
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obtained via MORECORE or MMAP.
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Trim support
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Fields holding the amount of unused topmost memory that should trigger
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timming, and a counter to force periodic scanning to release unused
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non-topmost segments.
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Locking
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If USE_LOCKS is defined, the "mutex" lock is acquired and released
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around every public call using this mspace.
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Extension support
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A void* pointer and a size_t field that can be used to help implement
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extensions to this malloc.
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*/
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/* Bin types, widths and sizes */
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#define NSMALLBINS (32U)
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#define NTREEBINS (32U)
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#define SMALLBIN_SHIFT (3U)
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#define SMALLBIN_WIDTH (SIZE_T_ONE << SMALLBIN_SHIFT)
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#define TREEBIN_SHIFT (8U)
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#define MIN_LARGE_SIZE (SIZE_T_ONE << TREEBIN_SHIFT)
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#define MAX_SMALL_SIZE (MIN_LARGE_SIZE - SIZE_T_ONE)
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#define MAX_SMALL_REQUEST (MAX_SMALL_SIZE - CHUNK_ALIGN_MASK - CHUNK_OVERHEAD)
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struct malloc_state {
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binmap_t smallmap;
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binmap_t treemap;
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size_t dvsize;
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size_t topsize;
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char* least_addr;
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mchunkptr dv;
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mchunkptr top;
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size_t trim_check;
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size_t release_checks;
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size_t magic;
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mchunkptr smallbins[(NSMALLBINS+1)*2];
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tbinptr treebins[NTREEBINS];
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size_t footprint;
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size_t max_footprint;
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flag_t mflags;
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__libc_lock_recursive_t lock; /* locate lock among fields that rarely change */
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msegment seg;
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void* extp; /* Unused but available for extensions */
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size_t exts;
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};
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typedef struct malloc_state* mstate;
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/* ------------- Global malloc_state and malloc_params ------------------- */
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/*
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malloc_params holds global properties, including those that can be
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dynamically set using mallopt. There is a single instance, mparams,
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initialized in init_mparams. Note that the non-zeroness of "magic"
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also serves as an initialization flag.
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*/
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struct malloc_params
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{
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volatile size_t magic;
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size_t page_size;
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size_t granularity;
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size_t mmap_threshold;
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size_t trim_threshold;
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flag_t default_mflags;
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};
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static struct malloc_params mparams;
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/* Ensure mparams initialized */
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#define ensure_initialization() (void)(mparams.magic != 0 || init_mparams())
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static struct malloc_state _gm_;
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#define gm (&_gm_)
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#define is_global(M) ((M) == &_gm_)
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#define is_initialized(M) ((M)->top != 0)
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__LOCK_INIT_RECURSIVE(static, malloc_global_mutex);
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#define ACQUIRE_MALLOC_GLOBAL_LOCK() __libc_lock_lock_recursive(malloc_global_mutex);
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#define RELEASE_MALLOC_GLOBAL_LOCK() __libc_lock_unlock_recursive(malloc_global_mutex);
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#define PREACTION(M) ( __libc_lock_lock_recursive((M)->lock))
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#define POSTACTION(M) { __libc_lock_unlock_recursive((M)->lock); }
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/* ---------------------------- Indexing Bins ---------------------------- */
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#define is_small(s) (((s) >> SMALLBIN_SHIFT) < NSMALLBINS)
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#define small_index(s) ((s) >> SMALLBIN_SHIFT)
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#define small_index2size(i) ((i) << SMALLBIN_SHIFT)
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#define MIN_SMALL_INDEX (small_index(MIN_CHUNK_SIZE))
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/* addressing by index. See above about smallbin repositioning */
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#define smallbin_at(M, i) ((sbinptr)((char*)&((M)->smallbins[(i)<<1])))
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#define treebin_at(M,i) (&((M)->treebins[i]))
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#define compute_tree_index(S, I)\
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{\
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unsigned int X = S >> TREEBIN_SHIFT;\
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if (X == 0)\
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I = 0;\
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else if (X > 0xFFFF)\
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I = NTREEBINS-1;\
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else {\
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unsigned int K;\
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__asm__("bsrl\t%1, %0\n\t" : "=r" (K) : "g" (X));\
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I = (bindex_t)((K << 1) + ((S >> (K + (TREEBIN_SHIFT-1)) & 1)));\
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}\
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}
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/* Bit representing maximum resolved size in a treebin at i */
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|
#define bit_for_tree_index(i) \
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(i == NTREEBINS-1)? (SIZE_T_BITSIZE-1) : (((i) >> 1) + TREEBIN_SHIFT - 2)
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|
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/* Shift placing maximum resolved bit in a treebin at i as sign bit */
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|
#define leftshift_for_tree_index(i) \
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((i == NTREEBINS-1)? 0 : \
|
|
((SIZE_T_BITSIZE-SIZE_T_ONE) - (((i) >> 1) + TREEBIN_SHIFT - 2)))
|
|
|
|
/* The size of the smallest chunk held in bin with index i */
|
|
#define minsize_for_tree_index(i) \
|
|
((SIZE_T_ONE << (((i) >> 1) + TREEBIN_SHIFT)) | \
|
|
(((size_t)((i) & SIZE_T_ONE)) << (((i) >> 1) + TREEBIN_SHIFT - 1)))
|
|
|
|
|
|
/* ------------------------ Operations on bin maps ----------------------- */
|
|
|
|
/* bit corresponding to given index */
|
|
#define idx2bit(i) ((binmap_t)(1) << (i))
|
|
|
|
/* Mark/Clear bits with given index */
|
|
#define mark_smallmap(M,i) ((M)->smallmap |= idx2bit(i))
|
|
#define clear_smallmap(M,i) ((M)->smallmap &= ~idx2bit(i))
|
|
#define smallmap_is_marked(M,i) ((M)->smallmap & idx2bit(i))
|
|
|
|
#define mark_treemap(M,i) ((M)->treemap |= idx2bit(i))
|
|
#define clear_treemap(M,i) ((M)->treemap &= ~idx2bit(i))
|
|
#define treemap_is_marked(M,i) ((M)->treemap & idx2bit(i))
|
|
|
|
/* isolate the least set bit of a bitmap */
|
|
#define least_bit(x) ((x) & -(x))
|
|
|
|
/* mask with all bits to left of least bit of x on */
|
|
#define left_bits(x) ((x<<1) | -(x<<1))
|
|
|
|
/* mask with all bits to left of or equal to least bit of x on */
|
|
#define same_or_left_bits(x) ((x) | -(x))
|
|
|
|
|
|
/* index corresponding to given bit. Use x86 asm if possible */
|
|
|
|
#define compute_bit2idx(X, I)\
|
|
{\
|
|
unsigned int J;\
|
|
__asm__("bsfl\t%1, %0\n\t" : "=r" (J) : "g" (X));\
|
|
I = (bindex_t)J;\
|
|
}
|
|
|
|
|
|
#define mark_inuse_foot(M,p,s)
|
|
|
|
/* Get/set size at footer */
|
|
#define get_foot(p, s) (((mchunkptr)((char*)(p) + (s)))->prev_foot)
|
|
#define set_foot(p, s) (((mchunkptr)((char*)(p) + (s)))->prev_foot = (s))
|
|
|
|
/* Macros for setting head/foot of non-mmapped chunks */
|
|
|
|
/* Set cinuse bit and pinuse bit of next chunk */
|
|
#define set_inuse(M,p,s)\
|
|
((p)->head = (((p)->head & PINUSE_BIT)|s|CINUSE_BIT),\
|
|
((mchunkptr)(((char*)(p)) + (s)))->head |= PINUSE_BIT)
|
|
|
|
/* Set cinuse and pinuse of this chunk and pinuse of next chunk */
|
|
#define set_inuse_and_pinuse(M,p,s)\
|
|
((p)->head = (s|PINUSE_BIT|CINUSE_BIT),\
|
|
((mchunkptr)(((char*)(p)) + (s)))->head |= PINUSE_BIT)
|
|
|
|
/* Set size, cinuse and pinuse bit of this chunk */
|
|
#define set_size_and_pinuse_of_inuse_chunk(M, p, s)\
|
|
((p)->head = (s|PINUSE_BIT|CINUSE_BIT))
|
|
|
|
|
|
#define assert(x)
|
|
#define RTCHECK(e) __builtin_expect(e, 1)
|
|
|
|
#define check_free_chunk(M,P)
|
|
#define check_inuse_chunk(M,P)
|
|
#define check_malloced_chunk(M,P,N)
|
|
#define check_mmapped_chunk(M,P)
|
|
#define check_malloc_state(M)
|
|
#define check_top_chunk(M,P)
|
|
|
|
/* Check if address a is at least as high as any from MORECORE or MMAP */
|
|
#define ok_address(M, a) ((char*)(a) >= (M)->least_addr)
|
|
/* Check if address of next chunk n is higher than base chunk p */
|
|
#define ok_next(p, n) ((char*)(p) < (char*)(n))
|
|
/* Check if p has inuse status */
|
|
#define ok_inuse(p) is_inuse(p)
|
|
/* Check if p has its pinuse bit on */
|
|
#define ok_pinuse(p) pinuse(p)
|
|
|
|
#define CORRUPTION_ERROR_ACTION(m) \
|
|
do { \
|
|
printf("%s malloc heap corrupted\n",__FUNCTION__); \
|
|
__asm__("int3"); \
|
|
}while(0) \
|
|
|
|
|
|
#define USAGE_ERROR_ACTION(m, p) \
|
|
do { \
|
|
printf("%s malloc heap corrupted\n",__FUNCTION__); \
|
|
__asm__("int3"); \
|
|
}while(0) \
|
|
|
|
/* ----------------------- Operations on smallbins ----------------------- */
|
|
|
|
/*
|
|
Various forms of linking and unlinking are defined as macros. Even
|
|
the ones for trees, which are very long but have very short typical
|
|
paths. This is ugly but reduces reliance on inlining support of
|
|
compilers.
|
|
*/
|
|
|
|
/* Link a free chunk into a smallbin */
|
|
#define insert_small_chunk(M, P, S) {\
|
|
bindex_t I = small_index(S);\
|
|
mchunkptr B = smallbin_at(M, I);\
|
|
mchunkptr F = B;\
|
|
assert(S >= MIN_CHUNK_SIZE);\
|
|
if (!smallmap_is_marked(M, I))\
|
|
mark_smallmap(M, I);\
|
|
else if (RTCHECK(ok_address(M, B->fd)))\
|
|
F = B->fd;\
|
|
else {\
|
|
CORRUPTION_ERROR_ACTION(M);\
|
|
}\
|
|
B->fd = P;\
|
|
F->bk = P;\
|
|
P->fd = F;\
|
|
P->bk = B;\
|
|
}
|
|
|
|
/* Unlink a chunk from a smallbin */
|
|
#define unlink_small_chunk(M, P, S) {\
|
|
mchunkptr F = P->fd;\
|
|
mchunkptr B = P->bk;\
|
|
bindex_t I = small_index(S);\
|
|
assert(P != B);\
|
|
assert(P != F);\
|
|
assert(chunksize(P) == small_index2size(I));\
|
|
if (F == B)\
|
|
clear_smallmap(M, I);\
|
|
else if (RTCHECK((F == smallbin_at(M,I) || ok_address(M, F)) &&\
|
|
(B == smallbin_at(M,I) || ok_address(M, B)))) {\
|
|
F->bk = B;\
|
|
B->fd = F;\
|
|
}\
|
|
else {\
|
|
CORRUPTION_ERROR_ACTION(M);\
|
|
}\
|
|
}
|
|
|
|
/* Unlink the first chunk from a smallbin */
|
|
#define unlink_first_small_chunk(M, B, P, I) {\
|
|
mchunkptr F = P->fd;\
|
|
assert(P != B);\
|
|
assert(P != F);\
|
|
assert(chunksize(P) == small_index2size(I));\
|
|
if (B == F)\
|
|
clear_smallmap(M, I);\
|
|
else if (RTCHECK(ok_address(M, F))) {\
|
|
B->fd = F;\
|
|
F->bk = B;\
|
|
}\
|
|
else {\
|
|
CORRUPTION_ERROR_ACTION(M);\
|
|
}\
|
|
}
|
|
|
|
/* Replace dv node, binning the old one */
|
|
/* Used only when dvsize known to be small */
|
|
#define replace_dv(M, P, S) {\
|
|
size_t DVS = M->dvsize;\
|
|
if (DVS != 0) {\
|
|
mchunkptr DV = M->dv;\
|
|
assert(is_small(DVS));\
|
|
insert_small_chunk(M, DV, DVS);\
|
|
}\
|
|
M->dvsize = S;\
|
|
M->dv = P;\
|
|
}
|
|
|
|
|
|
/* ------------------------- Operations on trees ------------------------- */
|
|
|
|
/* Insert chunk into tree */
|
|
#define insert_large_chunk(M, X, S) {\
|
|
tbinptr* H;\
|
|
bindex_t I;\
|
|
compute_tree_index(S, I);\
|
|
H = treebin_at(M, I);\
|
|
X->index = I;\
|
|
X->child[0] = X->child[1] = 0;\
|
|
if (!treemap_is_marked(M, I)) {\
|
|
mark_treemap(M, I);\
|
|
*H = X;\
|
|
X->parent = (tchunkptr)H;\
|
|
X->fd = X->bk = X;\
|
|
}\
|
|
else {\
|
|
tchunkptr T = *H;\
|
|
size_t K = S << leftshift_for_tree_index(I);\
|
|
for (;;) {\
|
|
if (chunksize(T) != S) {\
|
|
tchunkptr* C = &(T->child[(K >> (SIZE_T_BITSIZE-SIZE_T_ONE)) & 1]);\
|
|
K <<= 1;\
|
|
if (*C != 0)\
|
|
T = *C;\
|
|
else if (RTCHECK(ok_address(M, C))) {\
|
|
*C = X;\
|
|
X->parent = T;\
|
|
X->fd = X->bk = X;\
|
|
break;\
|
|
}\
|
|
else {\
|
|
CORRUPTION_ERROR_ACTION(M);\
|
|
break;\
|
|
}\
|
|
}\
|
|
else {\
|
|
tchunkptr F = T->fd;\
|
|
if (RTCHECK(ok_address(M, T) && ok_address(M, F))) {\
|
|
T->fd = F->bk = X;\
|
|
X->fd = F;\
|
|
X->bk = T;\
|
|
X->parent = 0;\
|
|
break;\
|
|
}\
|
|
else {\
|
|
CORRUPTION_ERROR_ACTION(M);\
|
|
break;\
|
|
}\
|
|
}\
|
|
}\
|
|
}\
|
|
}
|
|
|
|
/*
|
|
Unlink steps:
|
|
|
|
1. If x is a chained node, unlink it from its same-sized fd/bk links
|
|
and choose its bk node as its replacement.
|
|
2. If x was the last node of its size, but not a leaf node, it must
|
|
be replaced with a leaf node (not merely one with an open left or
|
|
right), to make sure that lefts and rights of descendents
|
|
correspond properly to bit masks. We use the rightmost descendent
|
|
of x. We could use any other leaf, but this is easy to locate and
|
|
tends to counteract removal of leftmosts elsewhere, and so keeps
|
|
paths shorter than minimally guaranteed. This doesn't loop much
|
|
because on average a node in a tree is near the bottom.
|
|
3. If x is the base of a chain (i.e., has parent links) relink
|
|
x's parent and children to x's replacement (or null if none).
|
|
*/
|
|
|
|
#define unlink_large_chunk(M, X) {\
|
|
tchunkptr XP = X->parent;\
|
|
tchunkptr R;\
|
|
if (X->bk != X) {\
|
|
tchunkptr F = X->fd;\
|
|
R = X->bk;\
|
|
if (RTCHECK(ok_address(M, F))) {\
|
|
F->bk = R;\
|
|
R->fd = F;\
|
|
}\
|
|
else {\
|
|
CORRUPTION_ERROR_ACTION(M);\
|
|
}\
|
|
}\
|
|
else {\
|
|
tchunkptr* RP;\
|
|
if (((R = *(RP = &(X->child[1]))) != 0) ||\
|
|
((R = *(RP = &(X->child[0]))) != 0)) {\
|
|
tchunkptr* CP;\
|
|
while ((*(CP = &(R->child[1])) != 0) ||\
|
|
(*(CP = &(R->child[0])) != 0)) {\
|
|
R = *(RP = CP);\
|
|
}\
|
|
if (RTCHECK(ok_address(M, RP)))\
|
|
*RP = 0;\
|
|
else {\
|
|
CORRUPTION_ERROR_ACTION(M);\
|
|
}\
|
|
}\
|
|
}\
|
|
if (XP != 0) {\
|
|
tbinptr* H = treebin_at(M, X->index);\
|
|
if (X == *H) {\
|
|
if ((*H = R) == 0) \
|
|
clear_treemap(M, X->index);\
|
|
}\
|
|
else if (RTCHECK(ok_address(M, XP))) {\
|
|
if (XP->child[0] == X) \
|
|
XP->child[0] = R;\
|
|
else \
|
|
XP->child[1] = R;\
|
|
}\
|
|
else\
|
|
CORRUPTION_ERROR_ACTION(M);\
|
|
if (R != 0) {\
|
|
if (RTCHECK(ok_address(M, R))) {\
|
|
tchunkptr C0, C1;\
|
|
R->parent = XP;\
|
|
if ((C0 = X->child[0]) != 0) {\
|
|
if (RTCHECK(ok_address(M, C0))) {\
|
|
R->child[0] = C0;\
|
|
C0->parent = R;\
|
|
}\
|
|
else\
|
|
CORRUPTION_ERROR_ACTION(M);\
|
|
}\
|
|
if ((C1 = X->child[1]) != 0) {\
|
|
if (RTCHECK(ok_address(M, C1))) {\
|
|
R->child[1] = C1;\
|
|
C1->parent = R;\
|
|
}\
|
|
else\
|
|
CORRUPTION_ERROR_ACTION(M);\
|
|
}\
|
|
}\
|
|
else\
|
|
CORRUPTION_ERROR_ACTION(M);\
|
|
}\
|
|
}\
|
|
}
|
|
|
|
/* Relays to large vs small bin operations */
|
|
|
|
#define insert_chunk(M, P, S)\
|
|
if (is_small(S)) insert_small_chunk(M, P, S)\
|
|
else { tchunkptr TP = (tchunkptr)(P); insert_large_chunk(M, TP, S); }
|
|
|
|
#define unlink_chunk(M, P, S)\
|
|
if (is_small(S)) unlink_small_chunk(M, P, S)\
|
|
else { tchunkptr TP = (tchunkptr)(P); unlink_large_chunk(M, TP); }
|
|
|
|
|
|
/* -------------------------- system alloc setup ------------------------- */
|
|
|
|
/* Operations on mflags */
|
|
|
|
#define use_lock(M) ((M)->mflags & USE_LOCK_BIT)
|
|
#define enable_lock(M) ((M)->mflags |= USE_LOCK_BIT)
|
|
#define disable_lock(M) ((M)->mflags &= ~USE_LOCK_BIT)
|
|
|
|
#define use_mmap(M) ((M)->mflags & USE_MMAP_BIT)
|
|
#define enable_mmap(M) ((M)->mflags |= USE_MMAP_BIT)
|
|
#define disable_mmap(M) ((M)->mflags &= ~USE_MMAP_BIT)
|
|
|
|
#define use_noncontiguous(M) ((M)->mflags & USE_NONCONTIGUOUS_BIT)
|
|
#define disable_contiguous(M) ((M)->mflags |= USE_NONCONTIGUOUS_BIT)
|
|
|
|
#define set_lock(M,L)\
|
|
((M)->mflags = (L)?\
|
|
((M)->mflags | USE_LOCK_BIT) :\
|
|
((M)->mflags & ~USE_LOCK_BIT))
|
|
|
|
/* page-align a size */
|
|
#define page_align(S)\
|
|
(((S) + (mparams.page_size - SIZE_T_ONE)) & ~(mparams.page_size - SIZE_T_ONE))
|
|
|
|
/* granularity-align a size */
|
|
#define granularity_align(S)\
|
|
(((S) + (mparams.granularity - SIZE_T_ONE))\
|
|
& ~(mparams.granularity - SIZE_T_ONE))
|
|
|
|
|
|
/* For mmap, use granularity alignment */
|
|
#define mmap_align(S) granularity_align(S)
|
|
|
|
/* For sys_alloc, enough padding to ensure can malloc request on success */
|
|
#define SYS_ALLOC_PADDING (TOP_FOOT_SIZE + MALLOC_ALIGNMENT)
|
|
|
|
#define is_page_aligned(S)\
|
|
(((size_t)(S) & (mparams.page_size - SIZE_T_ONE)) == 0)
|
|
#define is_granularity_aligned(S)\
|
|
(((size_t)(S) & (mparams.granularity - SIZE_T_ONE)) == 0)
|
|
|
|
/* True if segment S holds address A */
|
|
#define segment_holds(S, A)\
|
|
((char*)(A) >= S->base && (char*)(A) < S->base + S->size)
|
|
|
|
/* Return segment holding given address */
|
|
static msegmentptr segment_holding(mstate m, char* addr)
|
|
{
|
|
msegmentptr sp = &m->seg;
|
|
for (;;) {
|
|
if (addr >= sp->base && addr < sp->base + sp->size)
|
|
return sp;
|
|
if ((sp = sp->next) == 0)
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
/* Return true if segment contains a segment link */
|
|
static int has_segment_link(mstate m, msegmentptr ss)
|
|
{
|
|
msegmentptr sp = &m->seg;
|
|
for (;;) {
|
|
if ((char*)sp >= ss->base && (char*)sp < ss->base + ss->size)
|
|
return 1;
|
|
if ((sp = sp->next) == 0)
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
static inline void* os_mmap(size_t size)
|
|
{
|
|
void* ptr = user_alloc(size);
|
|
return (ptr != 0)? ptr: MFAIL;
|
|
}
|
|
|
|
static inline int os_munmap(void* ptr, size_t size)
|
|
{
|
|
return (user_free(ptr) != 0) ? 0 : -1;
|
|
}
|
|
|
|
#define should_trim(M,s) ((s) > (M)->trim_check)
|
|
|
|
|
|
#define MMAP_DEFAULT(s) os_mmap(s)
|
|
#define MUNMAP_DEFAULT(a, s) os_munmap((a), (s))
|
|
#define DIRECT_MMAP_DEFAULT(s) os_mmap(s)
|
|
|
|
#define internal_malloc(m, b) malloc(b)
|
|
#define internal_free(m, mem) free(mem)
|
|
|
|
/* ----------------------- Direct-mmapping chunks ----------------------- */
|
|
|
|
/*
|
|
Directly mmapped chunks are set up with an offset to the start of
|
|
the mmapped region stored in the prev_foot field of the chunk. This
|
|
allows reconstruction of the required argument to MUNMAP when freed,
|
|
and also allows adjustment of the returned chunk to meet alignment
|
|
requirements (especially in memalign).
|
|
*/
|
|
|
|
/* Malloc using mmap */
|
|
static void* mmap_alloc(mstate m, size_t nb)
|
|
{
|
|
size_t mmsize = mmap_align(nb + SIX_SIZE_T_SIZES + CHUNK_ALIGN_MASK);
|
|
if (mmsize > nb) /* Check for wrap around 0 */
|
|
{
|
|
char* mm = (char*)(os_mmap(mmsize));
|
|
if (mm != CMFAIL)
|
|
{
|
|
size_t offset = align_offset(chunk2mem(mm));
|
|
size_t psize = mmsize - offset - MMAP_FOOT_PAD;
|
|
mchunkptr p = (mchunkptr)(mm + offset);
|
|
p->prev_foot = offset;
|
|
p->head = psize;
|
|
mark_inuse_foot(m, p, psize);
|
|
chunk_plus_offset(p, psize)->head = FENCEPOST_HEAD;
|
|
chunk_plus_offset(p, psize+SIZE_T_SIZE)->head = 0;
|
|
|
|
if (m->least_addr == 0 || mm < m->least_addr)
|
|
m->least_addr = mm;
|
|
if ((m->footprint += mmsize) > m->max_footprint)
|
|
m->max_footprint = m->footprint;
|
|
assert(is_aligned(chunk2mem(p)));
|
|
check_mmapped_chunk(m, p);
|
|
return chunk2mem(p);
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/* Realloc using mmap */
|
|
static mchunkptr mmap_resize(mstate m, mchunkptr oldp, size_t nb)
|
|
{
|
|
size_t oldsize = chunksize(oldp);
|
|
if (is_small(nb)) /* Can't shrink mmap regions below small size */
|
|
return 0;
|
|
/* Keep old chunk if big enough but not too big */
|
|
if (oldsize >= nb + SIZE_T_SIZE &&
|
|
(oldsize - nb) <= (mparams.granularity << 1))
|
|
return oldp;
|
|
else
|
|
{
|
|
size_t offset = oldp->prev_foot;
|
|
size_t oldmmsize = oldsize + offset + MMAP_FOOT_PAD;
|
|
size_t newmmsize = mmap_align(nb + SIX_SIZE_T_SIZES + CHUNK_ALIGN_MASK);
|
|
char* cp = (char*)CALL_MREMAP((char*)oldp - offset,
|
|
oldmmsize, newmmsize, 1);
|
|
if (cp != CMFAIL)
|
|
{
|
|
mchunkptr newp = (mchunkptr)(cp + offset);
|
|
size_t psize = newmmsize - offset - MMAP_FOOT_PAD;
|
|
newp->head = psize;
|
|
mark_inuse_foot(m, newp, psize);
|
|
chunk_plus_offset(newp, psize)->head = FENCEPOST_HEAD;
|
|
chunk_plus_offset(newp, psize+SIZE_T_SIZE)->head = 0;
|
|
|
|
if (cp < m->least_addr)
|
|
m->least_addr = cp;
|
|
if ((m->footprint += newmmsize - oldmmsize) > m->max_footprint)
|
|
m->max_footprint = m->footprint;
|
|
check_mmapped_chunk(m, newp);
|
|
return newp;
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/* ---------------------------- setting mparams -------------------------- */
|
|
|
|
/* Initialize mparams */
|
|
static int init_mparams(void) {
|
|
|
|
ACQUIRE_MALLOC_GLOBAL_LOCK();
|
|
|
|
if (mparams.magic == 0)
|
|
{
|
|
size_t magic;
|
|
size_t psize;
|
|
size_t gsize;
|
|
|
|
psize = 4096;
|
|
gsize = DEFAULT_GRANULARITY;
|
|
|
|
/* Sanity-check configuration:
|
|
size_t must be unsigned and as wide as pointer type.
|
|
ints must be at least 4 bytes.
|
|
alignment must be at least 8.
|
|
Alignment, min chunk size, and page size must all be powers of 2.
|
|
*/
|
|
|
|
mparams.granularity = gsize;
|
|
mparams.page_size = psize;
|
|
mparams.mmap_threshold = DEFAULT_MMAP_THRESHOLD;
|
|
mparams.trim_threshold = DEFAULT_TRIM_THRESHOLD;
|
|
mparams.default_mflags = USE_LOCK_BIT|USE_MMAP_BIT|USE_NONCONTIGUOUS_BIT;
|
|
|
|
/* Set up lock for main malloc area */
|
|
gm->mflags = mparams.default_mflags;
|
|
__libc_lock_init_recursive(gm->lock);
|
|
|
|
magic = (size_t)(0x12345678 ^ (size_t)0x55555555U);
|
|
magic |= (size_t)8U; /* ensure nonzero */
|
|
magic &= ~(size_t)7U; /* improve chances of fault for bad values */
|
|
mparams.magic = magic;
|
|
}
|
|
|
|
RELEASE_MALLOC_GLOBAL_LOCK();
|
|
return 1;
|
|
}
|
|
|
|
/* -------------------------- mspace management -------------------------- */
|
|
|
|
/* Initialize top chunk and its size */
|
|
static void init_top(mstate m, mchunkptr p, size_t psize)
|
|
{
|
|
/* Ensure alignment */
|
|
size_t offset = align_offset(chunk2mem(p));
|
|
p = (mchunkptr)((char*)p + offset);
|
|
psize -= offset;
|
|
|
|
m->top = p;
|
|
m->topsize = psize;
|
|
p->head = psize | PINUSE_BIT;
|
|
/* set size of fake trailing chunk holding overhead space only once */
|
|
chunk_plus_offset(p, psize)->head = TOP_FOOT_SIZE;
|
|
m->trim_check = mparams.trim_threshold; /* reset on each update */
|
|
}
|
|
|
|
/* Initialize bins for a new mstate that is otherwise zeroed out */
|
|
static void init_bins(mstate m)
|
|
{
|
|
/* Establish circular links for smallbins */
|
|
bindex_t i;
|
|
for (i = 0; i < NSMALLBINS; ++i) {
|
|
sbinptr bin = smallbin_at(m,i);
|
|
bin->fd = bin->bk = bin;
|
|
}
|
|
}
|
|
|
|
/* Allocate chunk and prepend remainder with chunk in successor base. */
|
|
static void* prepend_alloc(mstate m, char* newbase, char* oldbase,
|
|
size_t nb)
|
|
{
|
|
mchunkptr p = align_as_chunk(newbase);
|
|
mchunkptr oldfirst = align_as_chunk(oldbase);
|
|
size_t psize = (char*)oldfirst - (char*)p;
|
|
mchunkptr q = chunk_plus_offset(p, nb);
|
|
size_t qsize = psize - nb;
|
|
set_size_and_pinuse_of_inuse_chunk(m, p, nb);
|
|
|
|
assert((char*)oldfirst > (char*)q);
|
|
assert(pinuse(oldfirst));
|
|
assert(qsize >= MIN_CHUNK_SIZE);
|
|
|
|
/* consolidate remainder with first chunk of old base */
|
|
if (oldfirst == m->top) {
|
|
size_t tsize = m->topsize += qsize;
|
|
m->top = q;
|
|
q->head = tsize | PINUSE_BIT;
|
|
check_top_chunk(m, q);
|
|
}
|
|
else if (oldfirst == m->dv) {
|
|
size_t dsize = m->dvsize += qsize;
|
|
m->dv = q;
|
|
set_size_and_pinuse_of_free_chunk(q, dsize);
|
|
}
|
|
else {
|
|
if (!is_inuse(oldfirst)) {
|
|
size_t nsize = chunksize(oldfirst);
|
|
unlink_chunk(m, oldfirst, nsize);
|
|
oldfirst = chunk_plus_offset(oldfirst, nsize);
|
|
qsize += nsize;
|
|
}
|
|
set_free_with_pinuse(q, qsize, oldfirst);
|
|
insert_chunk(m, q, qsize);
|
|
check_free_chunk(m, q);
|
|
}
|
|
|
|
check_malloced_chunk(m, chunk2mem(p), nb);
|
|
return chunk2mem(p);
|
|
}
|
|
|
|
/* Add a segment to hold a new noncontiguous region */
|
|
static void add_segment(mstate m, char* tbase, size_t tsize, flag_t mmapped)
|
|
{
|
|
/* Determine locations and sizes of segment, fenceposts, old top */
|
|
char* old_top = (char*)m->top;
|
|
msegmentptr oldsp = segment_holding(m, old_top);
|
|
char* old_end = oldsp->base + oldsp->size;
|
|
size_t ssize = pad_request(sizeof(struct malloc_segment));
|
|
char* rawsp = old_end - (ssize + FOUR_SIZE_T_SIZES + CHUNK_ALIGN_MASK);
|
|
size_t offset = align_offset(chunk2mem(rawsp));
|
|
char* asp = rawsp + offset;
|
|
char* csp = (asp < (old_top + MIN_CHUNK_SIZE))? old_top : asp;
|
|
mchunkptr sp = (mchunkptr)csp;
|
|
msegmentptr ss = (msegmentptr)(chunk2mem(sp));
|
|
mchunkptr tnext = chunk_plus_offset(sp, ssize);
|
|
mchunkptr p = tnext;
|
|
int nfences = 0;
|
|
|
|
/* reset top to new space */
|
|
init_top(m, (mchunkptr)tbase, tsize - TOP_FOOT_SIZE);
|
|
|
|
/* Set up segment record */
|
|
assert(is_aligned(ss));
|
|
set_size_and_pinuse_of_inuse_chunk(m, sp, ssize);
|
|
*ss = m->seg; /* Push current record */
|
|
m->seg.base = tbase;
|
|
m->seg.size = tsize;
|
|
m->seg.sflags = mmapped;
|
|
m->seg.next = ss;
|
|
|
|
/* Insert trailing fenceposts */
|
|
for (;;) {
|
|
mchunkptr nextp = chunk_plus_offset(p, SIZE_T_SIZE);
|
|
p->head = FENCEPOST_HEAD;
|
|
++nfences;
|
|
if ((char*)(&(nextp->head)) < old_end)
|
|
p = nextp;
|
|
else
|
|
break;
|
|
}
|
|
assert(nfences >= 2);
|
|
|
|
/* Insert the rest of old top into a bin as an ordinary free chunk */
|
|
if (csp != old_top) {
|
|
mchunkptr q = (mchunkptr)old_top;
|
|
size_t psize = csp - old_top;
|
|
mchunkptr tn = chunk_plus_offset(q, psize);
|
|
set_free_with_pinuse(q, psize, tn);
|
|
insert_chunk(m, q, psize);
|
|
}
|
|
|
|
check_top_chunk(m, m->top);
|
|
}
|
|
|
|
/* -------------------------- System allocation -------------------------- */
|
|
|
|
/* Get memory from system using MORECORE or MMAP */
|
|
static void* sys_alloc(mstate m, size_t nb)
|
|
{
|
|
char* tbase = CMFAIL;
|
|
size_t tsize = 0;
|
|
flag_t mmap_flag = 0;
|
|
|
|
ensure_initialization();
|
|
|
|
/* Directly map large chunks, but only if already initialized */
|
|
if (use_mmap(m) && nb >= mparams.mmap_threshold && m->topsize != 0)
|
|
{
|
|
void* mem = mmap_alloc(m, nb);
|
|
if (mem != 0)
|
|
return mem;
|
|
}
|
|
|
|
/*
|
|
Try getting memory in any of three ways (in most-preferred to
|
|
least-preferred order):
|
|
1. A call to MORECORE that can normally contiguously extend memory.
|
|
(disabled if not MORECORE_CONTIGUOUS or not HAVE_MORECORE or
|
|
or main space is mmapped or a previous contiguous call failed)
|
|
2. A call to MMAP new space (disabled if not HAVE_MMAP).
|
|
Note that under the default settings, if MORECORE is unable to
|
|
fulfill a request, and HAVE_MMAP is true, then mmap is
|
|
used as a noncontiguous system allocator. This is a useful backup
|
|
strategy for systems with holes in address spaces -- in this case
|
|
sbrk cannot contiguously expand the heap, but mmap may be able to
|
|
find space.
|
|
3. A call to MORECORE that cannot usually contiguously extend memory.
|
|
(disabled if not HAVE_MORECORE)
|
|
|
|
In all cases, we need to request enough bytes from system to ensure
|
|
we can malloc nb bytes upon success, so pad with enough space for
|
|
top_foot, plus alignment-pad to make sure we don't lose bytes if
|
|
not on boundary, and round this up to a granularity unit.
|
|
*/
|
|
|
|
if (HAVE_MMAP && tbase == CMFAIL) /* Try MMAP */
|
|
{
|
|
size_t rsize = granularity_align(nb + SYS_ALLOC_PADDING);
|
|
if (rsize > nb) /* Fail if wraps around zero */
|
|
{
|
|
char* mp = (char*)(CALL_MMAP(rsize));
|
|
if (mp != CMFAIL)
|
|
{
|
|
tbase = mp;
|
|
tsize = rsize;
|
|
mmap_flag = USE_MMAP_BIT;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (tbase != CMFAIL)
|
|
{
|
|
|
|
if ((m->footprint += tsize) > m->max_footprint)
|
|
m->max_footprint = m->footprint;
|
|
|
|
if (!is_initialized(m)) /* first-time initialization */
|
|
{
|
|
if (m->least_addr == 0 || tbase < m->least_addr)
|
|
m->least_addr = tbase;
|
|
m->seg.base = tbase;
|
|
m->seg.size = tsize;
|
|
m->seg.sflags = mmap_flag;
|
|
m->magic = mparams.magic;
|
|
m->release_checks = MAX_RELEASE_CHECK_RATE;
|
|
init_bins(m);
|
|
|
|
if (is_global(m))
|
|
init_top(m, (mchunkptr)tbase, tsize - TOP_FOOT_SIZE);
|
|
else
|
|
{
|
|
/* Offset top by embedded malloc_state */
|
|
mchunkptr mn = next_chunk(mem2chunk(m));
|
|
init_top(m, mn, (size_t)((tbase + tsize) - (char*)mn) -TOP_FOOT_SIZE);
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* Try to merge with an existing segment */
|
|
msegmentptr sp = &m->seg;
|
|
/* Only consider most recent segment if traversal suppressed */
|
|
while (sp != 0 && tbase != sp->base + sp->size)
|
|
sp = (NO_SEGMENT_TRAVERSAL) ? 0 : sp->next;
|
|
if (sp != 0 && !is_extern_segment(sp) &&
|
|
(sp->sflags & USE_MMAP_BIT) == mmap_flag &&
|
|
segment_holds(sp, m->top)) /* append */
|
|
{
|
|
sp->size += tsize;
|
|
init_top(m, m->top, m->topsize + tsize);
|
|
}
|
|
else
|
|
{
|
|
if (tbase < m->least_addr)
|
|
m->least_addr = tbase;
|
|
sp = &m->seg;
|
|
while (sp != 0 && sp->base != tbase + tsize)
|
|
sp = (NO_SEGMENT_TRAVERSAL) ? 0 : sp->next;
|
|
if (sp != 0 && !is_extern_segment(sp) &&
|
|
(sp->sflags & USE_MMAP_BIT) == mmap_flag)
|
|
{
|
|
char* oldbase = sp->base;
|
|
sp->base = tbase;
|
|
sp->size += tsize;
|
|
return prepend_alloc(m, tbase, oldbase, nb);
|
|
}
|
|
else
|
|
add_segment(m, tbase, tsize, mmap_flag);
|
|
}
|
|
}
|
|
|
|
if (nb < m->topsize) /* Allocate from new or extended top space */
|
|
{
|
|
size_t rsize = m->topsize -= nb;
|
|
mchunkptr p = m->top;
|
|
mchunkptr r = m->top = chunk_plus_offset(p, nb);
|
|
r->head = rsize | PINUSE_BIT;
|
|
set_size_and_pinuse_of_inuse_chunk(m, p, nb);
|
|
check_top_chunk(m, m->top);
|
|
check_malloced_chunk(m, chunk2mem(p), nb);
|
|
return chunk2mem(p);
|
|
}
|
|
}
|
|
|
|
MALLOC_FAILURE_ACTION;
|
|
return 0;
|
|
}
|
|
|
|
|
|
/* ----------------------- system deallocation -------------------------- */
|
|
|
|
/* Unmap and unlink any mmapped segments that don't contain used chunks */
|
|
static size_t release_unused_segments(mstate m)
|
|
{
|
|
size_t released = 0;
|
|
int nsegs = 0;
|
|
msegmentptr pred = &m->seg;
|
|
msegmentptr sp = pred->next;
|
|
while (sp != 0)
|
|
{
|
|
char* base = sp->base;
|
|
size_t size = sp->size;
|
|
msegmentptr next = sp->next;
|
|
++nsegs;
|
|
if (is_mmapped_segment(sp) && !is_extern_segment(sp))
|
|
{
|
|
mchunkptr p = align_as_chunk(base);
|
|
size_t psize = chunksize(p);
|
|
/* Can unmap if first chunk holds entire segment and not pinned */
|
|
if (!is_inuse(p) && (char*)p + psize >= base + size - TOP_FOOT_SIZE)
|
|
{
|
|
tchunkptr tp = (tchunkptr)p;
|
|
assert(segment_holds(sp, (char*)sp));
|
|
if (p == m->dv) {
|
|
m->dv = 0;
|
|
m->dvsize = 0;
|
|
}
|
|
else {
|
|
unlink_large_chunk(m, tp);
|
|
}
|
|
if (CALL_MUNMAP(base, size) == 0)
|
|
{
|
|
released += size;
|
|
m->footprint -= size;
|
|
/* unlink obsoleted record */
|
|
sp = pred;
|
|
sp->next = next;
|
|
}
|
|
else { /* back out if cannot unmap */
|
|
insert_large_chunk(m, tp, psize);
|
|
}
|
|
}
|
|
}
|
|
if (NO_SEGMENT_TRAVERSAL) /* scan only first segment */
|
|
break;
|
|
pred = sp;
|
|
sp = next;
|
|
}
|
|
/* Reset check counter */
|
|
m->release_checks = ((nsegs > MAX_RELEASE_CHECK_RATE)?
|
|
nsegs : MAX_RELEASE_CHECK_RATE);
|
|
return released;
|
|
}
|
|
|
|
static int sys_trim(mstate m, size_t pad)
|
|
{
|
|
size_t released = 0;
|
|
ensure_initialization();
|
|
if (pad < MAX_REQUEST && is_initialized(m))
|
|
{
|
|
pad += TOP_FOOT_SIZE; /* ensure enough room for segment overhead */
|
|
|
|
if (m->topsize > pad)
|
|
{
|
|
/* Shrink top space in granularity-size units, keeping at least one */
|
|
size_t unit = mparams.granularity;
|
|
size_t extra = ((m->topsize - pad + (unit - SIZE_T_ONE)) / unit -
|
|
SIZE_T_ONE) * unit;
|
|
msegmentptr sp = segment_holding(m, (char*)m->top);
|
|
|
|
if (!is_extern_segment(sp))
|
|
{
|
|
if (is_mmapped_segment(sp))
|
|
{
|
|
if (HAVE_MMAP &&
|
|
sp->size >= extra &&
|
|
!has_segment_link(m, sp)) /* can't shrink if pinned */
|
|
{
|
|
size_t newsize = sp->size - extra;
|
|
/* Prefer mremap, fall back to munmap */
|
|
if ((CALL_MREMAP(sp->base, sp->size, newsize, 0) != MFAIL) ||
|
|
(CALL_MUNMAP(sp->base + newsize, extra) == 0))
|
|
{
|
|
released = extra;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
if (released != 0)
|
|
{
|
|
sp->size -= released;
|
|
m->footprint -= released;
|
|
init_top(m, m->top, m->topsize - released);
|
|
check_top_chunk(m, m->top);
|
|
}
|
|
}
|
|
|
|
/* Unmap any unused mmapped segments */
|
|
if (HAVE_MMAP)
|
|
released += release_unused_segments(m);
|
|
|
|
/* On failure, disable autotrim to avoid repeated failed future calls */
|
|
if (released == 0 && m->topsize > m->trim_check)
|
|
m->trim_check = MAX_SIZE_T;
|
|
}
|
|
|
|
return (released != 0)? 1 : 0;
|
|
}
|
|
|
|
|
|
|
|
/* ---------------------------- malloc support --------------------------- */
|
|
|
|
/* allocate a large request from the best fitting chunk in a treebin */
|
|
static void* tmalloc_large(mstate m, size_t nb) {
|
|
tchunkptr v = 0;
|
|
size_t rsize = -nb; /* Unsigned negation */
|
|
tchunkptr t;
|
|
bindex_t idx;
|
|
compute_tree_index(nb, idx);
|
|
if ((t = *treebin_at(m, idx)) != 0) {
|
|
/* Traverse tree for this bin looking for node with size == nb */
|
|
size_t sizebits = nb << leftshift_for_tree_index(idx);
|
|
tchunkptr rst = 0; /* The deepest untaken right subtree */
|
|
for (;;) {
|
|
tchunkptr rt;
|
|
size_t trem = chunksize(t) - nb;
|
|
if (trem < rsize) {
|
|
v = t;
|
|
if ((rsize = trem) == 0)
|
|
break;
|
|
}
|
|
rt = t->child[1];
|
|
t = t->child[(sizebits >> (SIZE_T_BITSIZE-SIZE_T_ONE)) & 1];
|
|
if (rt != 0 && rt != t)
|
|
rst = rt;
|
|
if (t == 0) {
|
|
t = rst; /* set t to least subtree holding sizes > nb */
|
|
break;
|
|
}
|
|
sizebits <<= 1;
|
|
}
|
|
}
|
|
if (t == 0 && v == 0) { /* set t to root of next non-empty treebin */
|
|
binmap_t leftbits = left_bits(idx2bit(idx)) & m->treemap;
|
|
if (leftbits != 0) {
|
|
bindex_t i;
|
|
binmap_t leastbit = least_bit(leftbits);
|
|
compute_bit2idx(leastbit, i);
|
|
t = *treebin_at(m, i);
|
|
}
|
|
}
|
|
|
|
while (t != 0) { /* find smallest of tree or subtree */
|
|
size_t trem = chunksize(t) - nb;
|
|
if (trem < rsize) {
|
|
rsize = trem;
|
|
v = t;
|
|
}
|
|
t = leftmost_child(t);
|
|
}
|
|
|
|
/* If dv is a better fit, return 0 so malloc will use it */
|
|
if (v != 0 && rsize < (size_t)(m->dvsize - nb)) {
|
|
if (RTCHECK(ok_address(m, v))) { /* split */
|
|
mchunkptr r = chunk_plus_offset(v, nb);
|
|
assert(chunksize(v) == rsize + nb);
|
|
if (RTCHECK(ok_next(v, r))) {
|
|
unlink_large_chunk(m, v);
|
|
if (rsize < MIN_CHUNK_SIZE)
|
|
set_inuse_and_pinuse(m, v, (rsize + nb));
|
|
else {
|
|
set_size_and_pinuse_of_inuse_chunk(m, v, nb);
|
|
set_size_and_pinuse_of_free_chunk(r, rsize);
|
|
insert_chunk(m, r, rsize);
|
|
}
|
|
return chunk2mem(v);
|
|
}
|
|
}
|
|
CORRUPTION_ERROR_ACTION(m);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/* allocate a small request from the best fitting chunk in a treebin */
|
|
static void* tmalloc_small(mstate m, size_t nb)
|
|
{
|
|
tchunkptr t, v;
|
|
size_t rsize;
|
|
bindex_t i;
|
|
binmap_t leastbit = least_bit(m->treemap);
|
|
compute_bit2idx(leastbit, i);
|
|
v = t = *treebin_at(m, i);
|
|
rsize = chunksize(t) - nb;
|
|
|
|
while ((t = leftmost_child(t)) != 0) {
|
|
size_t trem = chunksize(t) - nb;
|
|
if (trem < rsize) {
|
|
rsize = trem;
|
|
v = t;
|
|
}
|
|
}
|
|
|
|
if (RTCHECK(ok_address(m, v))) {
|
|
mchunkptr r = chunk_plus_offset(v, nb);
|
|
assert(chunksize(v) == rsize + nb);
|
|
if (RTCHECK(ok_next(v, r))) {
|
|
unlink_large_chunk(m, v);
|
|
if (rsize < MIN_CHUNK_SIZE)
|
|
set_inuse_and_pinuse(m, v, (rsize + nb));
|
|
else {
|
|
set_size_and_pinuse_of_inuse_chunk(m, v, nb);
|
|
set_size_and_pinuse_of_free_chunk(r, rsize);
|
|
replace_dv(m, r, rsize);
|
|
}
|
|
return chunk2mem(v);
|
|
}
|
|
}
|
|
|
|
CORRUPTION_ERROR_ACTION(m);
|
|
return 0;
|
|
}
|
|
|
|
/* --------------------------- realloc support --------------------------- */
|
|
|
|
static void* internal_realloc(struct _reent *reent_ptr, mstate m, void* oldmem, size_t bytes)
|
|
{
|
|
if (bytes >= MAX_REQUEST)
|
|
{
|
|
MALLOC_FAILURE_ACTION;
|
|
return 0;
|
|
}
|
|
|
|
PREACTION(m);
|
|
{
|
|
mchunkptr oldp = mem2chunk(oldmem);
|
|
size_t oldsize = chunksize(oldp);
|
|
mchunkptr next = chunk_plus_offset(oldp, oldsize);
|
|
mchunkptr newp = 0;
|
|
void* extra = 0;
|
|
|
|
/* Try to either shrink or extend into top. Else malloc-copy-free */
|
|
|
|
if (RTCHECK(ok_address(m, oldp) && ok_inuse(oldp) &&
|
|
ok_next(oldp, next) && ok_pinuse(next)))
|
|
{
|
|
size_t nb = request2size(bytes);
|
|
if (is_mmapped(oldp))
|
|
newp = mmap_resize(m, oldp, nb);
|
|
else if (oldsize >= nb) { /* already big enough */
|
|
size_t rsize = oldsize - nb;
|
|
newp = oldp;
|
|
if (rsize >= MIN_CHUNK_SIZE)
|
|
{
|
|
mchunkptr remainder = chunk_plus_offset(newp, nb);
|
|
set_inuse(m, newp, nb);
|
|
set_inuse_and_pinuse(m, remainder, rsize);
|
|
extra = chunk2mem(remainder);
|
|
}
|
|
}
|
|
else if (next == m->top && oldsize + m->topsize > nb)
|
|
{
|
|
/* Expand into top */
|
|
size_t newsize = oldsize + m->topsize;
|
|
size_t newtopsize = newsize - nb;
|
|
mchunkptr newtop = chunk_plus_offset(oldp, nb);
|
|
set_inuse(m, oldp, nb);
|
|
newtop->head = newtopsize |PINUSE_BIT;
|
|
m->top = newtop;
|
|
m->topsize = newtopsize;
|
|
newp = oldp;
|
|
}
|
|
}
|
|
else {
|
|
USAGE_ERROR_ACTION(m, oldmem);
|
|
POSTACTION(m);
|
|
return 0;
|
|
}
|
|
#if DEBUG
|
|
if (newp != 0) {
|
|
check_inuse_chunk(m, newp); /* Check requires lock */
|
|
}
|
|
#endif
|
|
|
|
POSTACTION(m);
|
|
|
|
if (newp != 0)
|
|
{
|
|
if (extra != 0) {
|
|
_free_r(reent_ptr, extra);
|
|
}
|
|
return chunk2mem(newp);
|
|
}
|
|
else
|
|
{
|
|
void* newmem = _malloc_r(reent_ptr, bytes);
|
|
if (newmem != 0) {
|
|
size_t oc = oldsize - overhead_for(oldp);
|
|
memcpy(newmem, oldmem, (oc < bytes)? oc : bytes);
|
|
_free_r(reent_ptr, oldmem);
|
|
}
|
|
return newmem;
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/* --------------------------- memalign support -------------------------- */
|
|
|
|
static void* internal_memalign(mstate m, size_t alignment, size_t bytes)
|
|
{
|
|
if (alignment <= MALLOC_ALIGNMENT) /* Can just use malloc */
|
|
return internal_malloc(m, bytes);
|
|
if (alignment < MIN_CHUNK_SIZE) /* must be at least a minimum chunk size */
|
|
alignment = MIN_CHUNK_SIZE;
|
|
if ((alignment & (alignment-SIZE_T_ONE)) != 0) {/* Ensure a power of 2 */
|
|
size_t a = MALLOC_ALIGNMENT << 1;
|
|
while (a < alignment) a <<= 1;
|
|
alignment = a;
|
|
}
|
|
|
|
if (bytes >= MAX_REQUEST - alignment) {
|
|
if (m != 0) { /* Test isn't needed but avoids compiler warning */
|
|
MALLOC_FAILURE_ACTION;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
size_t nb = request2size(bytes);
|
|
size_t req = nb + alignment + MIN_CHUNK_SIZE - CHUNK_OVERHEAD;
|
|
char* mem = (char*)internal_malloc(m, req);
|
|
if (mem != 0)
|
|
{
|
|
void* leader = 0;
|
|
void* trailer = 0;
|
|
mchunkptr p = mem2chunk(mem);
|
|
|
|
PREACTION(m);
|
|
|
|
if ((((size_t)(mem)) % alignment) != 0) /* misaligned */
|
|
{
|
|
/*
|
|
Find an aligned spot inside chunk. Since we need to give
|
|
back leading space in a chunk of at least MIN_CHUNK_SIZE, if
|
|
the first calculation places us at a spot with less than
|
|
MIN_CHUNK_SIZE leader, we can move to the next aligned spot.
|
|
We've allocated enough total room so that this is always
|
|
possible.
|
|
*/
|
|
char* br = (char*)mem2chunk((size_t)(((size_t)(mem +
|
|
alignment -
|
|
SIZE_T_ONE)) &
|
|
-alignment));
|
|
char* pos = ((size_t)(br - (char*)(p)) >= MIN_CHUNK_SIZE)?
|
|
br : br+alignment;
|
|
mchunkptr newp = (mchunkptr)pos;
|
|
size_t leadsize = pos - (char*)(p);
|
|
size_t newsize = chunksize(p) - leadsize;
|
|
|
|
if (is_mmapped(p)) { /* For mmapped chunks, just adjust offset */
|
|
newp->prev_foot = p->prev_foot + leadsize;
|
|
newp->head = newsize;
|
|
}
|
|
else { /* Otherwise, give back leader, use the rest */
|
|
set_inuse(m, newp, newsize);
|
|
set_inuse(m, p, leadsize);
|
|
leader = chunk2mem(p);
|
|
}
|
|
p = newp;
|
|
}
|
|
|
|
/* Give back spare room at the end */
|
|
if (!is_mmapped(p))
|
|
{
|
|
size_t size = chunksize(p);
|
|
if (size > nb + MIN_CHUNK_SIZE)
|
|
{
|
|
size_t remainder_size = size - nb;
|
|
mchunkptr remainder = chunk_plus_offset(p, nb);
|
|
set_inuse(m, p, nb);
|
|
set_inuse(m, remainder, remainder_size);
|
|
trailer = chunk2mem(remainder);
|
|
}
|
|
}
|
|
|
|
assert (chunksize(p) >= nb);
|
|
assert((((size_t)(chunk2mem(p))) % alignment) == 0);
|
|
check_inuse_chunk(m, p);
|
|
POSTACTION(m);
|
|
if (leader != 0) {
|
|
internal_free(m, leader);
|
|
}
|
|
if (trailer != 0) {
|
|
internal_free(m, trailer);
|
|
}
|
|
return chunk2mem(p);
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
void* memalign(size_t alignment, size_t bytes)
|
|
{
|
|
return internal_memalign(gm, alignment, bytes);
|
|
}
|
|
|
|
|
|
|
|
void* _malloc_r(struct _reent *reent_ptr, size_t bytes) {
|
|
/*
|
|
Basic algorithm:
|
|
If a small request (< 256 bytes minus per-chunk overhead):
|
|
1. If one exists, use a remainderless chunk in associated smallbin.
|
|
(Remainderless means that there are too few excess bytes to
|
|
represent as a chunk.)
|
|
2. If it is big enough, use the dv chunk, which is normally the
|
|
chunk adjacent to the one used for the most recent small request.
|
|
3. If one exists, split the smallest available chunk in a bin,
|
|
saving remainder in dv.
|
|
4. If it is big enough, use the top chunk.
|
|
5. If available, get memory from system and use it
|
|
Otherwise, for a large request:
|
|
1. Find the smallest available binned chunk that fits, and use it
|
|
if it is better fitting than dv chunk, splitting if necessary.
|
|
2. If better fitting than any binned chunk, use the dv chunk.
|
|
3. If it is big enough, use the top chunk.
|
|
4. If request size >= mmap threshold, try to directly mmap this chunk.
|
|
5. If available, get memory from system and use it
|
|
|
|
The ugly goto's here ensure that postaction occurs along all paths.
|
|
*/
|
|
|
|
ensure_initialization(); /* initialize in sys_alloc if not using locks */
|
|
|
|
PREACTION(gm);
|
|
{
|
|
void* mem;
|
|
size_t nb;
|
|
|
|
if (bytes <= MAX_SMALL_REQUEST)
|
|
{
|
|
bindex_t idx;
|
|
binmap_t smallbits;
|
|
nb = (bytes < MIN_REQUEST)? MIN_CHUNK_SIZE : pad_request(bytes);
|
|
idx = small_index(nb);
|
|
smallbits = gm->smallmap >> idx;
|
|
|
|
if ((smallbits & 0x3U) != 0) /* Remainderless fit to a smallbin. */
|
|
{
|
|
mchunkptr b, p;
|
|
idx += ~smallbits & 1; /* Uses next bin if idx empty */
|
|
b = smallbin_at(gm, idx);
|
|
p = b->fd;
|
|
assert(chunksize(p) == small_index2size(idx));
|
|
unlink_first_small_chunk(gm, b, p, idx);
|
|
set_inuse_and_pinuse(gm, p, small_index2size(idx));
|
|
mem = chunk2mem(p);
|
|
check_malloced_chunk(gm, mem, nb);
|
|
goto postaction;
|
|
}
|
|
else if (nb > gm->dvsize)
|
|
{
|
|
if (smallbits != 0) /* Use chunk in next nonempty smallbin */
|
|
{
|
|
mchunkptr b, p, r;
|
|
size_t rsize;
|
|
bindex_t i;
|
|
binmap_t leftbits = (smallbits << idx) & left_bits(idx2bit(idx));
|
|
binmap_t leastbit = least_bit(leftbits);
|
|
compute_bit2idx(leastbit, i);
|
|
b = smallbin_at(gm, i);
|
|
p = b->fd;
|
|
assert(chunksize(p) == small_index2size(i));
|
|
unlink_first_small_chunk(gm, b, p, i);
|
|
rsize = small_index2size(i) - nb;
|
|
/* Fit here cannot be remainderless if 4byte sizes */
|
|
if (SIZE_T_SIZE != 4 && rsize < MIN_CHUNK_SIZE)
|
|
set_inuse_and_pinuse(gm, p, small_index2size(i));
|
|
else
|
|
{
|
|
set_size_and_pinuse_of_inuse_chunk(gm, p, nb);
|
|
r = chunk_plus_offset(p, nb);
|
|
set_size_and_pinuse_of_free_chunk(r, rsize);
|
|
replace_dv(gm, r, rsize);
|
|
}
|
|
mem = chunk2mem(p);
|
|
check_malloced_chunk(gm, mem, nb);
|
|
goto postaction;
|
|
}
|
|
else if (gm->treemap != 0 && (mem = tmalloc_small(gm, nb)) != 0)
|
|
{
|
|
check_malloced_chunk(gm, mem, nb);
|
|
goto postaction;
|
|
}
|
|
}
|
|
}
|
|
else if (bytes >= MAX_REQUEST)
|
|
nb = MAX_SIZE_T; /* Too big to allocate. Force failure (in sys alloc) */
|
|
else
|
|
{
|
|
nb = pad_request(bytes);
|
|
if (gm->treemap != 0 && (mem = tmalloc_large(gm, nb)) != 0)
|
|
{
|
|
check_malloced_chunk(gm, mem, nb);
|
|
goto postaction;
|
|
}
|
|
}
|
|
|
|
if (nb <= gm->dvsize) {
|
|
size_t rsize = gm->dvsize - nb;
|
|
mchunkptr p = gm->dv;
|
|
if (rsize >= MIN_CHUNK_SIZE) { /* split dv */
|
|
mchunkptr r = gm->dv = chunk_plus_offset(p, nb);
|
|
gm->dvsize = rsize;
|
|
set_size_and_pinuse_of_free_chunk(r, rsize);
|
|
set_size_and_pinuse_of_inuse_chunk(gm, p, nb);
|
|
}
|
|
else { /* exhaust dv */
|
|
size_t dvs = gm->dvsize;
|
|
gm->dvsize = 0;
|
|
gm->dv = 0;
|
|
set_inuse_and_pinuse(gm, p, dvs);
|
|
}
|
|
mem = chunk2mem(p);
|
|
check_malloced_chunk(gm, mem, nb);
|
|
goto postaction;
|
|
}
|
|
else if (nb < gm->topsize) { /* Split top */
|
|
size_t rsize = gm->topsize -= nb;
|
|
mchunkptr p = gm->top;
|
|
mchunkptr r = gm->top = chunk_plus_offset(p, nb);
|
|
r->head = rsize | PINUSE_BIT;
|
|
set_size_and_pinuse_of_inuse_chunk(gm, p, nb);
|
|
mem = chunk2mem(p);
|
|
check_top_chunk(gm, gm->top);
|
|
check_malloced_chunk(gm, mem, nb);
|
|
goto postaction;
|
|
}
|
|
|
|
mem = sys_alloc(gm, nb);
|
|
|
|
postaction:
|
|
POSTACTION(gm);
|
|
return mem;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
void _free_r(struct _reent *reent_ptr, void* mem) {
|
|
/*
|
|
Consolidate freed chunks with preceeding or succeeding bordering
|
|
free chunks, if they exist, and then place in a bin. Intermixed
|
|
with special cases for top, dv, mmapped chunks, and usage errors.
|
|
*/
|
|
|
|
if (mem != 0)
|
|
{
|
|
mchunkptr p = mem2chunk(mem);
|
|
|
|
#define fm gm
|
|
|
|
PREACTION(fm);
|
|
{
|
|
check_inuse_chunk(fm, p);
|
|
if (RTCHECK(ok_address(fm, p) && ok_inuse(p)))
|
|
{
|
|
size_t psize = chunksize(p);
|
|
mchunkptr next = chunk_plus_offset(p, psize);
|
|
if (!pinuse(p))
|
|
{
|
|
size_t prevsize = p->prev_foot;
|
|
if (is_mmapped(p))
|
|
{
|
|
psize += prevsize + MMAP_FOOT_PAD;
|
|
if (CALL_MUNMAP((char*)p - prevsize, psize) == 0)
|
|
fm->footprint -= psize;
|
|
goto postaction;
|
|
}
|
|
else
|
|
{
|
|
mchunkptr prev = chunk_minus_offset(p, prevsize);
|
|
psize += prevsize;
|
|
p = prev;
|
|
if (RTCHECK(ok_address(fm, prev))) /* consolidate backward */
|
|
{
|
|
if (p != fm->dv)
|
|
{
|
|
unlink_chunk(fm, p, prevsize);
|
|
}
|
|
else if ((next->head & INUSE_BITS) == INUSE_BITS)
|
|
{
|
|
fm->dvsize = psize;
|
|
set_free_with_pinuse(p, psize, next);
|
|
goto postaction;
|
|
}
|
|
}
|
|
else
|
|
goto erroraction;
|
|
}
|
|
}
|
|
|
|
if (RTCHECK(ok_next(p, next) && ok_pinuse(next)))
|
|
{
|
|
if (!cinuse(next)) /* consolidate forward */
|
|
{
|
|
if (next == fm->top)
|
|
{
|
|
size_t tsize = fm->topsize += psize;
|
|
fm->top = p;
|
|
p->head = tsize | PINUSE_BIT;
|
|
if (p == fm->dv)
|
|
{
|
|
fm->dv = 0;
|
|
fm->dvsize = 0;
|
|
}
|
|
if (should_trim(fm, tsize))
|
|
sys_trim(fm, 0);
|
|
goto postaction;
|
|
}
|
|
else if (next == fm->dv)
|
|
{
|
|
size_t dsize = fm->dvsize += psize;
|
|
fm->dv = p;
|
|
set_size_and_pinuse_of_free_chunk(p, dsize);
|
|
goto postaction;
|
|
}
|
|
else
|
|
{
|
|
size_t nsize = chunksize(next);
|
|
psize += nsize;
|
|
unlink_chunk(fm, next, nsize);
|
|
set_size_and_pinuse_of_free_chunk(p, psize);
|
|
if (p == fm->dv)
|
|
{
|
|
fm->dvsize = psize;
|
|
goto postaction;
|
|
}
|
|
}
|
|
}
|
|
else
|
|
set_free_with_pinuse(p, psize, next);
|
|
|
|
if (is_small(psize))
|
|
{
|
|
insert_small_chunk(fm, p, psize);
|
|
check_free_chunk(fm, p);
|
|
}
|
|
else
|
|
{
|
|
tchunkptr tp = (tchunkptr)p;
|
|
insert_large_chunk(fm, tp, psize);
|
|
check_free_chunk(fm, p);
|
|
if (--fm->release_checks == 0)
|
|
release_unused_segments(fm);
|
|
}
|
|
goto postaction;
|
|
}
|
|
}
|
|
erroraction:
|
|
USAGE_ERROR_ACTION(fm, p);
|
|
postaction:
|
|
POSTACTION(fm);
|
|
}
|
|
}
|
|
#undef fm
|
|
}
|
|
|
|
void* _calloc_r(struct _reent *reent_ptr, size_t n_elements, size_t elem_size) {
|
|
void* mem;
|
|
size_t req = 0;
|
|
if (n_elements != 0) {
|
|
req = n_elements * elem_size;
|
|
if (((n_elements | elem_size) & ~(size_t)0xffff) &&
|
|
(req / n_elements != elem_size))
|
|
req = MAX_SIZE_T; /* force downstream failure on overflow */
|
|
}
|
|
mem = _malloc_r(reent_ptr, req);
|
|
if (mem != 0 && calloc_must_clear(mem2chunk(mem)))
|
|
memset(mem, 0, req);
|
|
return mem;
|
|
}
|
|
|
|
void* _realloc_r (struct _reent *reent_ptr, void* oldmem, size_t bytes){
|
|
if (oldmem == 0)
|
|
return _malloc_r(reent_ptr, bytes);
|
|
#ifdef REALLOC_ZERO_BYTES_FREES
|
|
if (bytes == 0) {
|
|
_free_r(ptr, oldmem);
|
|
return 0;
|
|
}
|
|
#endif /* REALLOC_ZERO_BYTES_FREES */
|
|
else {
|
|
#if ! FOOTERS
|
|
mstate m = gm;
|
|
#else /* FOOTERS */
|
|
mstate m = get_mstate_for(mem2chunk(oldmem));
|
|
if (!ok_magic(m)) {
|
|
USAGE_ERROR_ACTION(m, oldmem);
|
|
return 0;
|
|
}
|
|
#endif /* FOOTERS */
|
|
return internal_realloc(reent_ptr, m, oldmem, bytes);
|
|
}
|
|
}
|
|
|
|
|
|
|
|
/* -----------------------------------------------------------------------
|
|
History:
|
|
V2.8.4 Wed May 27 09:56:23 2009 Doug Lea (dl at gee)
|
|
* Use zeros instead of prev foot for is_mmapped
|
|
* Add mspace_track_large_chunks; thanks to Jean Brouwers
|
|
* Fix set_inuse in internal_realloc; thanks to Jean Brouwers
|
|
* Fix insufficient sys_alloc padding when using 16byte alignment
|
|
* Fix bad error check in mspace_footprint
|
|
* Adaptations for ptmalloc; thanks to Wolfram Gloger.
|
|
* Reentrant spin locks; thanks to Earl Chew and others
|
|
* Win32 improvements; thanks to Niall Douglas and Earl Chew
|
|
* Add NO_SEGMENT_TRAVERSAL and MAX_RELEASE_CHECK_RATE options
|
|
* Extension hook in malloc_state
|
|
* Various small adjustments to reduce warnings on some compilers
|
|
* Various configuration extensions/changes for more platforms. Thanks
|
|
to all who contributed these.
|
|
|
|
V2.8.3 Thu Sep 22 11:16:32 2005 Doug Lea (dl at gee)
|
|
* Add max_footprint functions
|
|
* Ensure all appropriate literals are size_t
|
|
* Fix conditional compilation problem for some #define settings
|
|
* Avoid concatenating segments with the one provided
|
|
in create_mspace_with_base
|
|
* Rename some variables to avoid compiler shadowing warnings
|
|
* Use explicit lock initialization.
|
|
* Better handling of sbrk interference.
|
|
* Simplify and fix segment insertion, trimming and mspace_destroy
|
|
* Reinstate REALLOC_ZERO_BYTES_FREES option from 2.7.x
|
|
* Thanks especially to Dennis Flanagan for help on these.
|
|
|
|
V2.8.2 Sun Jun 12 16:01:10 2005 Doug Lea (dl at gee)
|
|
* Fix memalign brace error.
|
|
|
|
V2.8.1 Wed Jun 8 16:11:46 2005 Doug Lea (dl at gee)
|
|
* Fix improper #endif nesting in C++
|
|
* Add explicit casts needed for C++
|
|
|
|
V2.8.0 Mon May 30 14:09:02 2005 Doug Lea (dl at gee)
|
|
* Use trees for large bins
|
|
* Support mspaces
|
|
* Use segments to unify sbrk-based and mmap-based system allocation,
|
|
removing need for emulation on most platforms without sbrk.
|
|
* Default safety checks
|
|
* Optional footer checks. Thanks to William Robertson for the idea.
|
|
* Internal code refactoring
|
|
* Incorporate suggestions and platform-specific changes.
|
|
Thanks to Dennis Flanagan, Colin Plumb, Niall Douglas,
|
|
Aaron Bachmann, Emery Berger, and others.
|
|
* Speed up non-fastbin processing enough to remove fastbins.
|
|
* Remove useless cfree() to avoid conflicts with other apps.
|
|
* Remove internal memcpy, memset. Compilers handle builtins better.
|
|
* Remove some options that no one ever used and rename others.
|
|
|
|
V2.7.2 Sat Aug 17 09:07:30 2002 Doug Lea (dl at gee)
|
|
* Fix malloc_state bitmap array misdeclaration
|
|
|
|
V2.7.1 Thu Jul 25 10:58:03 2002 Doug Lea (dl at gee)
|
|
* Allow tuning of FIRST_SORTED_BIN_SIZE
|
|
* Use PTR_UINT as type for all ptr->int casts. Thanks to John Belmonte.
|
|
* Better detection and support for non-contiguousness of MORECORE.
|
|
Thanks to Andreas Mueller, Conal Walsh, and Wolfram Gloger
|
|
* Bypass most of malloc if no frees. Thanks To Emery Berger.
|
|
* Fix freeing of old top non-contiguous chunk im sysmalloc.
|
|
* Raised default trim and map thresholds to 256K.
|
|
* Fix mmap-related #defines. Thanks to Lubos Lunak.
|
|
* Fix copy macros; added LACKS_FCNTL_H. Thanks to Neal Walfield.
|
|
* Branch-free bin calculation
|
|
* Default trim and mmap thresholds now 256K.
|
|
|
|
V2.7.0 Sun Mar 11 14:14:06 2001 Doug Lea (dl at gee)
|
|
* Introduce independent_comalloc and independent_calloc.
|
|
Thanks to Michael Pachos for motivation and help.
|
|
* Make optional .h file available
|
|
* Allow > 2GB requests on 32bit systems.
|
|
* new WIN32 sbrk, mmap, munmap, lock code from <Walter@GeNeSys-e.de>.
|
|
Thanks also to Andreas Mueller <a.mueller at paradatec.de>,
|
|
and Anonymous.
|
|
* Allow override of MALLOC_ALIGNMENT (Thanks to Ruud Waij for
|
|
helping test this.)
|
|
* memalign: check alignment arg
|
|
* realloc: don't try to shift chunks backwards, since this
|
|
leads to more fragmentation in some programs and doesn't
|
|
seem to help in any others.
|
|
* Collect all cases in malloc requiring system memory into sysmalloc
|
|
* Use mmap as backup to sbrk
|
|
* Place all internal state in malloc_state
|
|
* Introduce fastbins (although similar to 2.5.1)
|
|
* Many minor tunings and cosmetic improvements
|
|
* Introduce USE_PUBLIC_MALLOC_WRAPPERS, USE_MALLOC_LOCK
|
|
* Introduce MALLOC_FAILURE_ACTION, MORECORE_CONTIGUOUS
|
|
Thanks to Tony E. Bennett <tbennett@nvidia.com> and others.
|
|
* Include errno.h to support default failure action.
|
|
|
|
V2.6.6 Sun Dec 5 07:42:19 1999 Doug Lea (dl at gee)
|
|
* return null for negative arguments
|
|
* Added Several WIN32 cleanups from Martin C. Fong <mcfong at yahoo.com>
|
|
* Add 'LACKS_SYS_PARAM_H' for those systems without 'sys/param.h'
|
|
(e.g. WIN32 platforms)
|
|
* Cleanup header file inclusion for WIN32 platforms
|
|
* Cleanup code to avoid Microsoft Visual C++ compiler complaints
|
|
* Add 'USE_DL_PREFIX' to quickly allow co-existence with existing
|
|
memory allocation routines
|
|
* Set 'malloc_getpagesize' for WIN32 platforms (needs more work)
|
|
* Use 'assert' rather than 'ASSERT' in WIN32 code to conform to
|
|
usage of 'assert' in non-WIN32 code
|
|
* Improve WIN32 'sbrk()' emulation's 'findRegion()' routine to
|
|
avoid infinite loop
|
|
* Always call 'fREe()' rather than 'free()'
|
|
|
|
V2.6.5 Wed Jun 17 15:57:31 1998 Doug Lea (dl at gee)
|
|
* Fixed ordering problem with boundary-stamping
|
|
|
|
V2.6.3 Sun May 19 08:17:58 1996 Doug Lea (dl at gee)
|
|
* Added pvalloc, as recommended by H.J. Liu
|
|
* Added 64bit pointer support mainly from Wolfram Gloger
|
|
* Added anonymously donated WIN32 sbrk emulation
|
|
* Malloc, calloc, getpagesize: add optimizations from Raymond Nijssen
|
|
* malloc_extend_top: fix mask error that caused wastage after
|
|
foreign sbrks
|
|
* Add linux mremap support code from HJ Liu
|
|
|
|
V2.6.2 Tue Dec 5 06:52:55 1995 Doug Lea (dl at gee)
|
|
* Integrated most documentation with the code.
|
|
* Add support for mmap, with help from
|
|
Wolfram Gloger (Gloger@lrz.uni-muenchen.de).
|
|
* Use last_remainder in more cases.
|
|
* Pack bins using idea from colin@nyx10.cs.du.edu
|
|
* Use ordered bins instead of best-fit threshhold
|
|
* Eliminate block-local decls to simplify tracing and debugging.
|
|
* Support another case of realloc via move into top
|
|
* Fix error occuring when initial sbrk_base not word-aligned.
|
|
* Rely on page size for units instead of SBRK_UNIT to
|
|
avoid surprises about sbrk alignment conventions.
|
|
* Add mallinfo, mallopt. Thanks to Raymond Nijssen
|
|
(raymond@es.ele.tue.nl) for the suggestion.
|
|
* Add `pad' argument to malloc_trim and top_pad mallopt parameter.
|
|
* More precautions for cases where other routines call sbrk,
|
|
courtesy of Wolfram Gloger (Gloger@lrz.uni-muenchen.de).
|
|
* Added macros etc., allowing use in linux libc from
|
|
H.J. Lu (hjl@gnu.ai.mit.edu)
|
|
* Inverted this history list
|
|
|
|
V2.6.1 Sat Dec 2 14:10:57 1995 Doug Lea (dl at gee)
|
|
* Re-tuned and fixed to behave more nicely with V2.6.0 changes.
|
|
* Removed all preallocation code since under current scheme
|
|
the work required to undo bad preallocations exceeds
|
|
the work saved in good cases for most test programs.
|
|
* No longer use return list or unconsolidated bins since
|
|
no scheme using them consistently outperforms those that don't
|
|
given above changes.
|
|
* Use best fit for very large chunks to prevent some worst-cases.
|
|
* Added some support for debugging
|
|
|
|
V2.6.0 Sat Nov 4 07:05:23 1995 Doug Lea (dl at gee)
|
|
* Removed footers when chunks are in use. Thanks to
|
|
Paul Wilson (wilson@cs.texas.edu) for the suggestion.
|
|
|
|
V2.5.4 Wed Nov 1 07:54:51 1995 Doug Lea (dl at gee)
|
|
* Added malloc_trim, with help from Wolfram Gloger
|
|
(wmglo@Dent.MED.Uni-Muenchen.DE).
|
|
|
|
V2.5.3 Tue Apr 26 10:16:01 1994 Doug Lea (dl at g)
|
|
|
|
V2.5.2 Tue Apr 5 16:20:40 1994 Doug Lea (dl at g)
|
|
* realloc: try to expand in both directions
|
|
* malloc: swap order of clean-bin strategy;
|
|
* realloc: only conditionally expand backwards
|
|
* Try not to scavenge used bins
|
|
* Use bin counts as a guide to preallocation
|
|
* Occasionally bin return list chunks in first scan
|
|
* Add a few optimizations from colin@nyx10.cs.du.edu
|
|
|
|
V2.5.1 Sat Aug 14 15:40:43 1993 Doug Lea (dl at g)
|
|
* faster bin computation & slightly different binning
|
|
* merged all consolidations to one part of malloc proper
|
|
(eliminating old malloc_find_space & malloc_clean_bin)
|
|
* Scan 2 returns chunks (not just 1)
|
|
* Propagate failure in realloc if malloc returns 0
|
|
* Add stuff to allow compilation on non-ANSI compilers
|
|
from kpv@research.att.com
|
|
|
|
V2.5 Sat Aug 7 07:41:59 1993 Doug Lea (dl at g.oswego.edu)
|
|
* removed potential for odd address access in prev_chunk
|
|
* removed dependency on getpagesize.h
|
|
* misc cosmetics and a bit more internal documentation
|
|
* anticosmetics: mangled names in macros to evade debugger strangeness
|
|
* tested on sparc, hp-700, dec-mips, rs6000
|
|
with gcc & native cc (hp, dec only) allowing
|
|
Detlefs & Zorn comparison study (in SIGPLAN Notices.)
|
|
|
|
Trial version Fri Aug 28 13:14:29 1992 Doug Lea (dl at g.oswego.edu)
|
|
* Based loosely on libg++-1.2X malloc. (It retains some of the overall
|
|
structure of old version, but most details differ.)
|
|
|
|
*/
|
|
|