perl/malloc.c
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   1/*    malloc.c
   2 *
   3 */
   4
   5/*
   6 * 'The Chamber of Records,' said Gimli.  'I guess that is where we now stand.'
   7 *
   8 *     [p.321 of _The Lord of the Rings_, II/v: "The Bridge of Khazad-Dûm"]
   9 */
  10
  11/* This file contains Perl's own implementation of the malloc library.
  12 * It is used if Configure decides that, on your platform, Perl's
  13 * version is better than the OS's, or if you give Configure the
  14 * -Dusemymalloc command-line option.
  15 */
  16
  17/*
  18  Here are some notes on configuring Perl's malloc.  (For non-perl
  19  usage see below.)
  20 
  21  There are two macros which serve as bulk disablers of advanced
  22  features of this malloc: NO_FANCY_MALLOC, PLAIN_MALLOC (undef by
  23  default).  Look in the list of default values below to understand
  24  their exact effect.  Defining NO_FANCY_MALLOC returns malloc.c to the
  25  state of the malloc in Perl 5.004.  Additionally defining PLAIN_MALLOC
  26  returns it to the state as of Perl 5.000.
  27
  28  Note that some of the settings below may be ignored in the code based
  29  on values of other macros.  The PERL_CORE symbol is only defined when
  30  perl itself is being compiled (so malloc can make some assumptions
  31  about perl's facilities being available to it).
  32
  33  Each config option has a short description, followed by its name,
  34  default value, and a comment about the default (if applicable).  Some
  35  options take a precise value, while the others are just boolean.
  36  The boolean ones are listed first.
  37
  38    # Read configuration settings from malloc_cfg.h
  39    HAVE_MALLOC_CFG_H           undef
  40
  41    # Enable code for an emergency memory pool in $^M.  See perlvar.pod
  42    # for a description of $^M.
  43    PERL_EMERGENCY_SBRK         (!PLAIN_MALLOC && (PERL_CORE || !NO_MALLOC_DYNAMIC_CFG))
  44
  45    # Enable code for printing memory statistics.
  46    DEBUGGING_MSTATS            (!PLAIN_MALLOC && PERL_CORE)
  47
  48    # Move allocation info for small buckets into separate areas.
  49    # Memory optimization (especially for small allocations, of the
  50    # less than 64 bytes).  Since perl usually makes a large number
  51    # of small allocations, this is usually a win.
  52    PACK_MALLOC                 (!PLAIN_MALLOC && !RCHECK)
  53
  54    # Add one page to big powers of two when calculating bucket size.
  55    # This is targeted at big allocations, as are common in image
  56    # processing.
  57    TWO_POT_OPTIMIZE            !PLAIN_MALLOC
  58 
  59    # Use intermediate bucket sizes between powers-of-two.  This is
  60    # generally a memory optimization, and a (small) speed pessimization.
  61    BUCKETS_ROOT2               !NO_FANCY_MALLOC
  62
  63    # Do not check small deallocations for bad free().  Memory
  64    # and speed optimization, error reporting pessimization.
  65    IGNORE_SMALL_BAD_FREE       (!NO_FANCY_MALLOC && !RCHECK)
  66
  67    # Use table lookup to decide in which bucket a given allocation will go.
  68    SMALL_BUCKET_VIA_TABLE      !NO_FANCY_MALLOC
  69
  70    # Use a perl-defined sbrk() instead of the (presumably broken or
  71    # missing) system-supplied sbrk().
  72    USE_PERL_SBRK               undef
  73
  74    # Use system malloc() (or calloc() etc.) to emulate sbrk(). Normally
  75    # only used with broken sbrk()s.
  76    PERL_SBRK_VIA_MALLOC        undef
  77
  78    # Which allocator to use if PERL_SBRK_VIA_MALLOC
  79    SYSTEM_ALLOC(a)             malloc(a)
  80
  81    # Minimal alignment (in bytes, should be a power of 2) of SYSTEM_ALLOC
  82    SYSTEM_ALLOC_ALIGNMENT      MEM_ALIGNBYTES
  83
  84    # Disable memory overwrite checking with DEBUGGING.  Memory and speed
  85    # optimization, error reporting pessimization.
  86    NO_RCHECK                   undef
  87
  88    # Enable memory overwrite checking with DEBUGGING.  Memory and speed
  89    # pessimization, error reporting optimization
  90    RCHECK                      (DEBUGGING && !NO_RCHECK)
  91
  92    # Do not overwrite uninit areas with DEBUGGING.  Speed
  93    # optimization, error reporting pessimization
  94    NO_MFILL                    undef
  95
  96    # Overwrite uninit areas with DEBUGGING.  Speed
  97    # pessimization, error reporting optimization
  98    MALLOC_FILL                 (DEBUGGING && !NO_RCHECK && !NO_MFILL)
  99
 100    # Do not check overwritten uninit areas with DEBUGGING.  Speed
 101    # optimization, error reporting pessimization
 102    NO_FILL_CHECK               undef
 103
 104    # Check overwritten uninit areas with DEBUGGING.  Speed
 105    # pessimization, error reporting optimization
 106    MALLOC_FILL_CHECK           (DEBUGGING && !NO_RCHECK && !NO_FILL_CHECK)
 107
 108    # Failed allocations bigger than this size croak (if
 109    # PERL_EMERGENCY_SBRK is enabled) without touching $^M.  See
 110    # perlvar.pod for a description of $^M.
 111    BIG_SIZE                     (1<<16)        # 64K
 112
 113    # Starting from this power of two, add an extra page to the
 114    # size of the bucket. This enables optimized allocations of sizes
 115    # close to powers of 2.  Note that the value is indexed at 0.
 116    FIRST_BIG_POW2              15              # 32K, 16K is used too often
 117
 118    # Estimate of minimal memory footprint.  malloc uses this value to
 119    # request the most reasonable largest blocks of memory from the system.
 120    FIRST_SBRK                  (48*1024)
 121
 122    # Round up sbrk()s to multiples of this.
 123    MIN_SBRK                    2048
 124
 125    # Round up sbrk()s to multiples of this percent of footprint.
 126    MIN_SBRK_FRAC               3
 127
 128    # Round up sbrk()s to multiples of this multiple of 1/1000 of footprint.
 129    MIN_SBRK_FRAC1000           (10 * MIN_SBRK_FRAC)
 130
 131    # Add this much memory to big powers of two to get the bucket size.
 132    PERL_PAGESIZE               4096
 133
 134    # This many sbrk() discontinuities should be tolerated even
 135    # from the start without deciding that sbrk() is usually
 136    # discontinuous.
 137    SBRK_ALLOW_FAILURES         3
 138
 139    # This many continuous sbrk()s compensate for one discontinuous one.
 140    SBRK_FAILURE_PRICE          50
 141
 142    # Some configurations may ask for 12-byte-or-so allocations which
 143    # require 8-byte alignment (?!).  In such situation one needs to
 144    # define this to disable 12-byte bucket (will increase memory footprint)
 145    STRICT_ALIGNMENT            undef
 146
 147    # Do not allow configuration of runtime options at runtime
 148    NO_MALLOC_DYNAMIC_CFG       undef
 149
 150    # Do not allow configuration of runtime options via $ENV{PERL_MALLOC_OPT}
 151    NO_PERL_MALLOC_ENV          undef
 152
 153        [The variable consists of ;-separated parts of the form CODE=VALUE
 154         with 1-character codes F, M, f, A, P, G, d, a, c for runtime
 155         configuration of FIRST_SBRK, MIN_SBRK, MIN_SBRK_FRAC1000,
 156         SBRK_ALLOW_FAILURES, SBRK_FAILURE_PRICE, sbrk_goodness,
 157         filldead, fillalive, fillcheck.  The last 3 are for DEBUGGING
 158         build, and allow switching the tests for free()ed memory read,
 159         uninit memory reads, and free()ed memory write.]
 160
 161  This implementation assumes that calling PerlIO_printf() does not
 162  result in any memory allocation calls (used during a panic).
 163
 164 */
 165
 166/*
 167   If used outside of Perl environment, it may be useful to redefine
 168   the following macros (listed below with defaults):
 169
 170     # Type of address returned by allocation functions
 171     Malloc_t                           void *
 172
 173     # Type of size argument for allocation functions
 174     MEM_SIZE                           unsigned long
 175
 176     # size of void*
 177     PTRSIZE                            4
 178
 179     # Maximal value in LONG
 180     LONG_MAX                           0x7FFFFFFF
 181
 182     # Unsigned integer type big enough to keep a pointer
 183     UV                                 unsigned long
 184
 185     # Signed integer of the same sizeof() as UV
 186     IV                                 long
 187
 188     # Type of pointer with 1-byte granularity
 189     caddr_t                            char *
 190
 191     # Type returned by free()
 192     Free_t                             void
 193
 194     # Conversion of pointer to integer
 195     PTR2UV(ptr)                        ((UV)(ptr))
 196
 197     # Conversion of integer to pointer
 198     INT2PTR(type, i)                   ((type)(i))
 199
 200     # printf()-%-Conversion of UV to pointer
 201     UVuf                               "lu"
 202
 203     # printf()-%-Conversion of UV to hex pointer
 204     UVxf                               "lx"
 205
 206     # Alignment to use
 207     MEM_ALIGNBYTES                     4
 208
 209     # Very fatal condition reporting function (cannot call any )
 210     fatalcroak(arg)                    write(2,arg,strlen(arg)) + exit(2)
 211  
 212     # Fatal error reporting function
 213     croak(format, arg)                 warn(idem) + exit(1)
 214  
 215     # Fatal error reporting function
 216     croak2(format, arg1, arg2)         warn2(idem) + exit(1)
 217  
 218     # Error reporting function
 219     warn(format, arg)                  fprintf(stderr, idem)
 220
 221     # Error reporting function
 222     warn2(format, arg1, arg2)          fprintf(stderr, idem)
 223
 224     # Locking/unlocking for MT operation
 225     MALLOC_LOCK                        MUTEX_LOCK(&PL_malloc_mutex)
 226     MALLOC_UNLOCK                      MUTEX_UNLOCK(&PL_malloc_mutex)
 227
 228     # Locking/unlocking mutex for MT operation
 229     MUTEX_LOCK(l)                      void
 230     MUTEX_UNLOCK(l)                    void
 231 */
 232
 233#ifdef HAVE_MALLOC_CFG_H
 234#  include "malloc_cfg.h"
 235#endif
 236
 237#ifndef NO_FANCY_MALLOC
 238#  ifndef SMALL_BUCKET_VIA_TABLE
 239#    define SMALL_BUCKET_VIA_TABLE
 240#  endif 
 241#  ifndef BUCKETS_ROOT2
 242#    define BUCKETS_ROOT2
 243#  endif 
 244#  ifndef IGNORE_SMALL_BAD_FREE
 245#    define IGNORE_SMALL_BAD_FREE
 246#  endif 
 247#endif 
 248
 249#ifndef PLAIN_MALLOC                    /* Bulk enable features */
 250#  ifndef PACK_MALLOC
 251#      define PACK_MALLOC
 252#  endif 
 253#  ifndef TWO_POT_OPTIMIZE
 254#    define TWO_POT_OPTIMIZE
 255#  endif 
 256#  if (defined(PERL_CORE) || !defined(NO_MALLOC_DYNAMIC_CFG)) && !defined(PERL_EMERGENCY_SBRK)
 257#    define PERL_EMERGENCY_SBRK
 258#  endif 
 259#  if defined(PERL_CORE) && !defined(DEBUGGING_MSTATS)
 260#    define DEBUGGING_MSTATS
 261#  endif 
 262#endif
 263
 264#define MIN_BUC_POW2 (sizeof(void*) > 4 ? 3 : 2) /* Allow for 4-byte arena. */
 265#define MIN_BUCKET (MIN_BUC_POW2 * BUCKETS_PER_POW2)
 266
 267#if !(defined(I286) || defined(atarist) || defined(__MINT__))
 268        /* take 2k unless the block is bigger than that */
 269#  define LOG_OF_MIN_ARENA 11
 270#else
 271        /* take 16k unless the block is bigger than that 
 272           (80286s like large segments!), probably good on the atari too */
 273#  define LOG_OF_MIN_ARENA 14
 274#endif
 275
 276#if defined(DEBUGGING) && !defined(NO_RCHECK)
 277#  define RCHECK
 278#endif
 279#if defined(DEBUGGING) && !defined(NO_RCHECK) && !defined(NO_MFILL) && !defined(MALLOC_FILL)
 280#  define MALLOC_FILL
 281#endif
 282#if defined(DEBUGGING) && !defined(NO_RCHECK) && !defined(NO_FILL_CHECK) && !defined(MALLOC_FILL_CHECK)
 283#  define MALLOC_FILL_CHECK
 284#endif
 285#if defined(RCHECK) && defined(IGNORE_SMALL_BAD_FREE)
 286#  undef IGNORE_SMALL_BAD_FREE
 287#endif 
 288/*
 289 * malloc.c (Caltech) 2/21/82
 290 * Chris Kingsley, kingsley@cit-20.
 291 *
 292 * This is a very fast storage allocator.  It allocates blocks of a small 
 293 * number of different sizes, and keeps free lists of each size.  Blocks that
 294 * don't exactly fit are passed up to the next larger size.  In this 
 295 * implementation, the available sizes are 2^n-4 (or 2^n-12) bytes long.
 296 * If PACK_MALLOC is defined, small blocks are 2^n bytes long.
 297 * This is designed for use in a program that uses vast quantities of memory,
 298 * but bombs when it runs out.
 299 * 
 300 * Modifications Copyright Ilya Zakharevich 1996-99.
 301 * 
 302 * Still very quick, but much more thrifty.  (Std config is 10% slower
 303 * than it was, and takes 67% of old heap size for typical usage.)
 304 *
 305 * Allocations of small blocks are now table-driven to many different
 306 * buckets.  Sizes of really big buckets are increased to accomodata
 307 * common size=power-of-2 blocks.  Running-out-of-memory is made into
 308 * an exception.  Deeply configurable and thread-safe.
 309 * 
 310 */
 311
 312#ifdef PERL_CORE
 313#  include "EXTERN.h"
 314#  define PERL_IN_MALLOC_C
 315#  include "perl.h"
 316#  if defined(PERL_IMPLICIT_CONTEXT)
 317#    define croak       Perl_croak_nocontext
 318#    define croak2      Perl_croak_nocontext
 319#    define warn        Perl_warn_nocontext
 320#    define warn2       Perl_warn_nocontext
 321#  else
 322#    define croak2      croak
 323#    define warn2       warn
 324#  endif
 325#  if defined(USE_5005THREADS) || defined(USE_ITHREADS)
 326#     define PERL_MAYBE_ALIVE   PL_thr_key
 327#  else
 328#     define PERL_MAYBE_ALIVE   1
 329#  endif
 330#else
 331#  ifdef PERL_FOR_X2P
 332#    include "../EXTERN.h"
 333#    include "../perl.h"
 334#  else
 335#    include <stdlib.h>
 336#    include <stdio.h>
 337#    include <memory.h>
 338#    ifdef OS2
 339#      include <io.h>
 340#    endif
 341#    include <string.h>
 342#    ifndef Malloc_t
 343#      define Malloc_t void *
 344#    endif
 345#    ifndef PTRSIZE
 346#      define PTRSIZE 4
 347#    endif
 348#    ifndef MEM_SIZE
 349#      define MEM_SIZE unsigned long
 350#    endif
 351#    ifndef LONG_MAX
 352#      define LONG_MAX 0x7FFFFFFF
 353#    endif
 354#    ifndef UV
 355#      define UV unsigned long
 356#    endif
 357#    ifndef IV
 358#      define IV long
 359#    endif
 360#    ifndef caddr_t
 361#      define caddr_t char *
 362#    endif
 363#    ifndef Free_t
 364#      define Free_t void
 365#    endif
 366#    define Copy(s,d,n,t) (void)memcpy((char*)(d),(char*)(s), (n) * sizeof(t))
 367#    define CopyD(s,d,n,t) memcpy((char*)(d),(char*)(s), (n) * sizeof(t))
 368#    define PerlEnv_getenv getenv
 369#    define PerlIO_printf fprintf
 370#    define PerlIO_stderr() stderr
 371#    define PerlIO_puts(f,s)            fputs(s,f)
 372#    ifndef INT2PTR
 373#      define INT2PTR(t,i)              ((t)(i))
 374#    endif
 375#    ifndef PTR2UV
 376#      define PTR2UV(p)                 ((UV)(p))
 377#    endif
 378#    ifndef UVuf
 379#      define UVuf                      "lu"
 380#    endif
 381#    ifndef UVxf
 382#      define UVxf                      "lx"
 383#    endif
 384#    ifndef MEM_ALIGNBYTES
 385#      define MEM_ALIGNBYTES            4
 386#    endif
 387#  endif
 388#  ifndef croak                         /* make depend */
 389#    define croak(mess, arg) (warn((mess), (arg)), exit(1))
 390#  endif 
 391#  ifndef croak2                        /* make depend */
 392#    define croak2(mess, arg1, arg2) (warn2((mess), (arg1), (arg2)), exit(1))
 393#  endif 
 394#  ifndef warn
 395#    define warn(mess, arg) fprintf(stderr, (mess), (arg))
 396#  endif 
 397#  ifndef warn2
 398#    define warn2(mess, arg1, arg2) fprintf(stderr, (mess), (arg1), (arg2))
 399#  endif 
 400#  ifdef DEBUG_m
 401#    undef DEBUG_m
 402#  endif 
 403#  define DEBUG_m(a)
 404#  ifdef DEBUGGING
 405#     undef DEBUGGING
 406#  endif
 407#  ifndef pTHX
 408#     define pTHX               void
 409#     define pTHX_
 410#     ifdef HASATTRIBUTE_UNUSED
 411#        define dTHX            extern int Perl___notused PERL_UNUSED_DECL
 412#     else
 413#        define dTHX            extern int Perl___notused
 414#     endif
 415#     define WITH_THX(s)        s
 416#  endif
 417#  ifndef PERL_GET_INTERP
 418#     define PERL_GET_INTERP    PL_curinterp
 419#  endif
 420#  define PERL_MAYBE_ALIVE      1
 421#  ifndef Perl_malloc
 422#     define Perl_malloc malloc
 423#  endif
 424#  ifndef Perl_mfree
 425#     define Perl_mfree free
 426#  endif
 427#  ifndef Perl_realloc
 428#     define Perl_realloc realloc
 429#  endif
 430#  ifndef Perl_calloc
 431#     define Perl_calloc calloc
 432#  endif
 433#  ifndef Perl_strdup
 434#     define Perl_strdup strdup
 435#  endif
 436#endif  /* defined PERL_CORE */
 437
 438#ifndef MUTEX_LOCK
 439#  define MUTEX_LOCK(l)
 440#endif 
 441
 442#ifndef MUTEX_UNLOCK
 443#  define MUTEX_UNLOCK(l)
 444#endif 
 445
 446#ifndef MALLOC_LOCK
 447#  define MALLOC_LOCK           MUTEX_LOCK(&PL_malloc_mutex)
 448#endif 
 449
 450#ifndef MALLOC_UNLOCK
 451#  define MALLOC_UNLOCK         MUTEX_UNLOCK(&PL_malloc_mutex)
 452#endif 
 453
 454#  ifndef fatalcroak                            /* make depend */
 455#    define fatalcroak(mess)    (write(2, (mess), strlen(mess)), exit(2))
 456#  endif 
 457
 458#ifdef DEBUGGING
 459#  undef DEBUG_m
 460#  define DEBUG_m(a)                                                    \
 461    STMT_START {                                                        \
 462        if (PERL_MAYBE_ALIVE && PERL_GET_THX) {                                         \
 463            dTHX;                                                       \
 464            if (DEBUG_m_TEST) {                                         \
 465                PL_debug &= ~DEBUG_m_FLAG;                              \
 466                a;                                                      \
 467                PL_debug |= DEBUG_m_FLAG;                               \
 468            }                                                           \
 469        }                                                               \
 470    } STMT_END
 471#endif
 472
 473#ifdef PERL_IMPLICIT_CONTEXT
 474#  define PERL_IS_ALIVE         aTHX
 475#else
 476#  define PERL_IS_ALIVE         TRUE
 477#endif
 478    
 479
 480/*
 481 * Layout of memory:
 482 * ~~~~~~~~~~~~~~~~
 483 * The memory is broken into "blocks" which occupy multiples of 2K (and
 484 * generally speaking, have size "close" to a power of 2).  The addresses
 485 * of such *unused* blocks are kept in nextf[i] with big enough i.  (nextf
 486 * is an array of linked lists.)  (Addresses of used blocks are not known.)
 487 * 
 488 * Moreover, since the algorithm may try to "bite" smaller blocks out
 489 * of unused bigger ones, there are also regions of "irregular" size,
 490 * managed separately, by a linked list chunk_chain.
 491 * 
 492 * The third type of storage is the sbrk()ed-but-not-yet-used space, its
 493 * end and size are kept in last_sbrk_top and sbrked_remains.
 494 * 
 495 * Growing blocks "in place":
 496 * ~~~~~~~~~~~~~~~~~~~~~~~~~
 497 * The address of the block with the greatest address is kept in last_op
 498 * (if not known, last_op is 0).  If it is known that the memory above
 499 * last_op is not continuous, or contains a chunk from chunk_chain,
 500 * last_op is set to 0.
 501 * 
 502 * The chunk with address last_op may be grown by expanding into
 503 * sbrk()ed-but-not-yet-used space, or trying to sbrk() more continuous
 504 * memory.
 505 * 
 506 * Management of last_op:
 507 * ~~~~~~~~~~~~~~~~~~~~~
 508 * 
 509 * free() never changes the boundaries of blocks, so is not relevant.
 510 * 
 511 * The only way realloc() may change the boundaries of blocks is if it
 512 * grows a block "in place".  However, in the case of success such a
 513 * chunk is automatically last_op, and it remains last_op.  In the case
 514 * of failure getpages_adjacent() clears last_op.
 515 * 
 516 * malloc() may change blocks by calling morecore() only.
 517 * 
 518 * morecore() may create new blocks by:
 519 *   a) biting pieces from chunk_chain (cannot create one above last_op);
 520 *   b) biting a piece from an unused block (if block was last_op, this
 521 *      may create a chunk from chain above last_op, thus last_op is
 522 *      invalidated in such a case).
 523 *   c) biting of sbrk()ed-but-not-yet-used space.  This creates 
 524 *      a block which is last_op.
 525 *   d) Allocating new pages by calling getpages();
 526 * 
 527 * getpages() creates a new block.  It marks last_op at the bottom of
 528 * the chunk of memory it returns.
 529 * 
 530 * Active pages footprint:
 531 * ~~~~~~~~~~~~~~~~~~~~~~
 532 * Note that we do not need to traverse the lists in nextf[i], just take
 533 * the first element of this list.  However, we *need* to traverse the
 534 * list in chunk_chain, but most the time it should be a very short one,
 535 * so we do not step on a lot of pages we are not going to use.
 536 * 
 537 * Flaws:
 538 * ~~~~~
 539 * get_from_bigger_buckets(): forget to increment price => Quite
 540 * aggressive.
 541 */
 542
 543/* I don't much care whether these are defined in sys/types.h--LAW */
 544
 545#define u_char unsigned char
 546#define u_int unsigned int
 547/* 
 548 * I removed the definition of u_bigint which appeared to be u_bigint = UV
 549 * u_bigint was only used in TWOK_MASKED and TWOK_SHIFT 
 550 * where I have used PTR2UV.  RMB
 551 */
 552#define u_short unsigned short
 553
 554/* 286 and atarist like big chunks, which gives too much overhead. */
 555#if (defined(RCHECK) || defined(I286) || defined(atarist) || defined(__MINT__)) && defined(PACK_MALLOC)
 556#  undef PACK_MALLOC
 557#endif 
 558
 559/*
 560 * The description below is applicable if PACK_MALLOC is not defined.
 561 *
 562 * The overhead on a block is at least 4 bytes.  When free, this space
 563 * contains a pointer to the next free block, and the bottom two bits must
 564 * be zero.  When in use, the first byte is set to MAGIC, and the second
 565 * byte is the size index.  The remaining bytes are for alignment.
 566 * If range checking is enabled and the size of the block fits
 567 * in two bytes, then the top two bytes hold the size of the requested block
 568 * plus the range checking words, and the header word MINUS ONE.
 569 */
 570union   overhead {
 571        union   overhead *ov_next;      /* when free */
 572#if MEM_ALIGNBYTES > 4
 573        double  strut;                  /* alignment problems */
 574#  if MEM_ALIGNBYTES > 8
 575        char    sstrut[MEM_ALIGNBYTES]; /* for the sizing */
 576#  endif
 577#endif
 578        struct {
 579/*
 580 * Keep the ovu_index and ovu_magic in this order, having a char
 581 * field first gives alignment indigestion in some systems, such as
 582 * MachTen.
 583 */
 584                u_char  ovu_index;      /* bucket # */
 585                u_char  ovu_magic;      /* magic number */
 586#ifdef RCHECK
 587            /* Subtract one to fit into u_short for an extra bucket */
 588                u_short ovu_size;       /* block size (requested + overhead - 1) */
 589                u_int   ovu_rmagic;     /* range magic number */
 590#endif
 591        } ovu;
 592#define ov_magic        ovu.ovu_magic
 593#define ov_index        ovu.ovu_index
 594#define ov_size         ovu.ovu_size
 595#define ov_rmagic       ovu.ovu_rmagic
 596};
 597
 598#define MAGIC           0xff            /* magic # on accounting info */
 599#define RMAGIC          0x55555555      /* magic # on range info */
 600#define RMAGIC_C        0x55            /* magic # on range info */
 601
 602#ifdef RCHECK
 603#  define       RMAGIC_SZ       sizeof (u_int) /* Overhead at end of bucket */
 604#  ifdef TWO_POT_OPTIMIZE
 605#    define MAX_SHORT_BUCKET (12 * BUCKETS_PER_POW2) /* size-1 fits in short */
 606#  else
 607#    define MAX_SHORT_BUCKET (13 * BUCKETS_PER_POW2)
 608#  endif 
 609#else
 610#  define       RMAGIC_SZ       0
 611#endif
 612
 613#if !defined(PACK_MALLOC) && defined(BUCKETS_ROOT2)
 614#  undef BUCKETS_ROOT2
 615#endif 
 616
 617#ifdef BUCKETS_ROOT2
 618#  define BUCKET_TABLE_SHIFT 2
 619#  define BUCKET_POW2_SHIFT 1
 620#  define BUCKETS_PER_POW2 2
 621#else
 622#  define BUCKET_TABLE_SHIFT MIN_BUC_POW2
 623#  define BUCKET_POW2_SHIFT 0
 624#  define BUCKETS_PER_POW2 1
 625#endif 
 626
 627#if !defined(MEM_ALIGNBYTES) || ((MEM_ALIGNBYTES > 4) && !defined(STRICT_ALIGNMENT))
 628/* Figure out the alignment of void*. */
 629struct aligner {
 630  char c;
 631  void *p;
 632};
 633#  define ALIGN_SMALL ((int)((caddr_t)&(((struct aligner*)0)->p)))
 634#else
 635#  define ALIGN_SMALL MEM_ALIGNBYTES
 636#endif
 637
 638#define IF_ALIGN_8(yes,no)      ((ALIGN_SMALL>4) ? (yes) : (no))
 639
 640#ifdef BUCKETS_ROOT2
 641#  define MAX_BUCKET_BY_TABLE 13
 642static const u_short buck_size[MAX_BUCKET_BY_TABLE + 1] = 
 643  { 
 644      0, 0, 0, 0, 4, 4, 8, 12, 16, 24, 32, 48, 64, 80,
 645  };
 646#  define BUCKET_SIZE_NO_SURPLUS(i) ((i) % 2 ? buck_size[i] : (1 << ((i) >> BUCKET_POW2_SHIFT)))
 647#  define BUCKET_SIZE_REAL(i) ((i) <= MAX_BUCKET_BY_TABLE               \
 648                               ? buck_size[i]                           \
 649                               : ((1 << ((i) >> BUCKET_POW2_SHIFT))     \
 650                                  - MEM_OVERHEAD(i)                     \
 651                                  + POW2_OPTIMIZE_SURPLUS(i)))
 652#else
 653#  define BUCKET_SIZE_NO_SURPLUS(i) (1 << ((i) >> BUCKET_POW2_SHIFT))
 654#  define BUCKET_SIZE(i) (BUCKET_SIZE_NO_SURPLUS(i) + POW2_OPTIMIZE_SURPLUS(i))
 655#  define BUCKET_SIZE_REAL(i) (BUCKET_SIZE(i) - MEM_OVERHEAD(i))
 656#endif 
 657
 658
 659#ifdef PACK_MALLOC
 660/* In this case there are several possible layout of arenas depending
 661 * on the size.  Arenas are of sizes multiple to 2K, 2K-aligned, and
 662 * have a size close to a power of 2.
 663 *
 664 * Arenas of the size >= 4K keep one chunk only.  Arenas of size 2K
 665 * may keep one chunk or multiple chunks.  Here are the possible
 666 * layouts of arenas:
 667 *
 668 *      # One chunk only, chunksize 2^k + SOMETHING - ALIGN, k >= 11
 669 *
 670 * INDEX MAGIC1 UNUSED CHUNK1
 671 *
 672 *      # Multichunk with sanity checking and chunksize 2^k-ALIGN, k>7
 673 *
 674 * INDEX MAGIC1 MAGIC2 MAGIC3 UNUSED CHUNK1 CHUNK2 CHUNK3 ...
 675 *
 676 *      # Multichunk with sanity checking and size 2^k-ALIGN, k=7
 677 *
 678 * INDEX MAGIC1 MAGIC2 MAGIC3 UNUSED CHUNK1 UNUSED CHUNK2 CHUNK3 ...
 679 *
 680 *      # Multichunk with sanity checking and size up to 80
 681 *
 682 * INDEX UNUSED MAGIC1 UNUSED MAGIC2 UNUSED ... CHUNK1 CHUNK2 CHUNK3 ...
 683 *
 684 *      # No sanity check (usually up to 48=byte-long buckets)
 685 * INDEX UNUSED CHUNK1 CHUNK2 ...
 686 *
 687 * Above INDEX and MAGIC are one-byte-long.  Sizes of UNUSED are
 688 * appropriate to keep algorithms simple and memory aligned.  INDEX
 689 * encodes the size of the chunk, while MAGICn encodes state (used,
 690 * free or non-managed-by-us-so-it-indicates-a-bug) of CHUNKn.  MAGIC
 691 * is used for sanity checking purposes only.  SOMETHING is 0 or 4K
 692 * (to make size of big CHUNK accomodate allocations for powers of two
 693 * better).
 694 *
 695 * [There is no need to alignment between chunks, since C rules ensure
 696 *  that structs which need 2^k alignment have sizeof which is
 697 *  divisible by 2^k.  Thus as far as the last chunk is aligned at the
 698 *  end of the arena, and 2K-alignment does not contradict things,
 699 *  everything is going to be OK for sizes of chunks 2^n and 2^n +
 700 *  2^k.  Say, 80-bit buckets will be 16-bit aligned, and as far as we
 701 *  put allocations for requests in 65..80 range, all is fine.
 702 *
 703 *  Note, however, that standard malloc() puts more strict
 704 *  requirements than the above C rules.  Moreover, our algorithms of
 705 *  realloc() may break this idyll, but we suppose that realloc() does
 706 *  need not change alignment.]
 707 *
 708 * Is very important to make calculation of the offset of MAGICm as
 709 * quick as possible, since it is done on each malloc()/free().  In
 710 * fact it is so quick that it has quite little effect on the speed of
 711 * doing malloc()/free().  [By default] We forego such calculations
 712 * for small chunks, but only to save extra 3% of memory, not because
 713 * of speed considerations.
 714 *
 715 * Here is the algorithm [which is the same for all the allocations
 716 * schemes above], see OV_MAGIC(block,bucket).  Let OFFSETm be the
 717 * offset of the CHUNKm from the start of ARENA.  Then offset of
 718 * MAGICm is (OFFSET1 >> SHIFT) + ADDOFFSET.  Here SHIFT and ADDOFFSET
 719 * are numbers which depend on the size of the chunks only.
 720 *
 721 * Let as check some sanity conditions.  Numbers OFFSETm>>SHIFT are
 722 * different for all the chunks in the arena if 2^SHIFT is not greater
 723 * than size of the chunks in the arena.  MAGIC1 will not overwrite
 724 * INDEX provided ADDOFFSET is >0 if OFFSET1 < 2^SHIFT.  MAGIClast
 725 * will not overwrite CHUNK1 if OFFSET1 > (OFFSETlast >> SHIFT) +
 726 * ADDOFFSET.
 727 * 
 728 * Make SHIFT the maximal possible (there is no point in making it
 729 * smaller).  Since OFFSETlast is 2K - CHUNKSIZE, above restrictions
 730 * give restrictions on OFFSET1 and on ADDOFFSET.
 731 * 
 732 * In particular, for chunks of size 2^k with k>=6 we can put
 733 * ADDOFFSET to be from 0 to 2^k - 2^(11-k), and have
 734 * OFFSET1==chunksize.  For chunks of size 80 OFFSET1 of 2K%80=48 is
 735 * large enough to have ADDOFFSET between 1 and 16 (similarly for 96,
 736 * when ADDOFFSET should be 1).  In particular, keeping MAGICs for
 737 * these sizes gives no additional size penalty.
 738 * 
 739 * However, for chunks of size 2^k with k<=5 this gives OFFSET1 >=
 740 * ADDOFSET + 2^(11-k).  Keeping ADDOFFSET 0 allows for 2^(11-k)-2^(11-2k)
 741 * chunks per arena.  This is smaller than 2^(11-k) - 1 which are
 742 * needed if no MAGIC is kept.  [In fact, having a negative ADDOFFSET
 743 * would allow for slightly more buckets per arena for k=2,3.]
 744 * 
 745 * Similarly, for chunks of size 3/2*2^k with k<=5 MAGICs would span
 746 * the area up to 2^(11-k)+ADDOFFSET.  For k=4 this give optimal
 747 * ADDOFFSET as -7..0.  For k=3 ADDOFFSET can go up to 4 (with tiny
 748 * savings for negative ADDOFFSET).  For k=5 ADDOFFSET can go -1..16
 749 * (with no savings for negative values).
 750 *
 751 * In particular, keeping ADDOFFSET 0 for sizes of chunks up to 2^6
 752 * leads to tiny pessimizations in case of sizes 4, 8, 12, 24, and
 753 * leads to no contradictions except for size=80 (or 96.)
 754 *
 755 * However, it also makes sense to keep no magic for sizes 48 or less.
 756 * This is what we do.  In this case one needs ADDOFFSET>=1 also for
 757 * chunksizes 12, 24, and 48, unless one gets one less chunk per
 758 * arena.
 759 *  
 760 * The algo of OV_MAGIC(block,bucket) keeps ADDOFFSET 0 until
 761 * chunksize of 64, then makes it 1. 
 762 *
 763 * This allows for an additional optimization: the above scheme leads
 764 * to giant overheads for sizes 128 or more (one whole chunk needs to
 765 * be sacrifised to keep INDEX).  Instead we use chunks not of size
 766 * 2^k, but of size 2^k-ALIGN.  If we pack these chunks at the end of
 767 * the arena, then the beginnings are still in different 2^k-long
 768 * sections of the arena if k>=7 for ALIGN==4, and k>=8 if ALIGN=8.
 769 * Thus for k>7 the above algo of calculating the offset of the magic
 770 * will still give different answers for different chunks.  And to
 771 * avoid the overrun of MAGIC1 into INDEX, one needs ADDOFFSET of >=1.
 772 * In the case k=7 we just move the first chunk an extra ALIGN
 773 * backward inside the ARENA (this is done once per arena lifetime,
 774 * thus is not a big overhead).  */
 775#  define MAX_PACKED_POW2 6
 776#  define MAX_PACKED (MAX_PACKED_POW2 * BUCKETS_PER_POW2 + BUCKET_POW2_SHIFT)
 777#  define MAX_POW2_ALGO ((1<<(MAX_PACKED_POW2 + 1)) - M_OVERHEAD)
 778#  define TWOK_MASK ((1<<LOG_OF_MIN_ARENA) - 1)
 779#  define TWOK_MASKED(x) (PTR2UV(x) & ~TWOK_MASK)
 780#  define TWOK_SHIFT(x) (PTR2UV(x) & TWOK_MASK)
 781#  define OV_INDEXp(block) (INT2PTR(u_char*,TWOK_MASKED(block)))
 782#  define OV_INDEX(block) (*OV_INDEXp(block))
 783#  define OV_MAGIC(block,bucket) (*(OV_INDEXp(block) +                  \
 784                                    (TWOK_SHIFT(block)>>                \
 785                                     (bucket>>BUCKET_POW2_SHIFT)) +     \
 786                                    (bucket >= MIN_NEEDS_SHIFT ? 1 : 0)))
 787    /* A bucket can have a shift smaller than it size, we need to
 788       shift its magic number so it will not overwrite index: */
 789#  ifdef BUCKETS_ROOT2
 790#    define MIN_NEEDS_SHIFT (7*BUCKETS_PER_POW2 - 1) /* Shift 80 greater than chunk 64. */
 791#  else
 792#    define MIN_NEEDS_SHIFT (7*BUCKETS_PER_POW2) /* Shift 128 greater than chunk 32. */
 793#  endif 
 794#  define CHUNK_SHIFT 0
 795
 796/* Number of active buckets of given ordinal. */
 797#ifdef IGNORE_SMALL_BAD_FREE
 798#define FIRST_BUCKET_WITH_CHECK (6 * BUCKETS_PER_POW2) /* 64 */
 799#  define N_BLKS(bucket) ( (bucket) < FIRST_BUCKET_WITH_CHECK           \
 800                         ? ((1<<LOG_OF_MIN_ARENA) - 1)/BUCKET_SIZE_NO_SURPLUS(bucket) \
 801                         : n_blks[bucket] )
 802#else
 803#  define N_BLKS(bucket) n_blks[bucket]
 804#endif 
 805
 806static const u_short n_blks[LOG_OF_MIN_ARENA * BUCKETS_PER_POW2] =
 807  {
 808#  if BUCKETS_PER_POW2==1
 809      0, 0,
 810      (MIN_BUC_POW2==2 ? 384 : 0),
 811      224, 120, 62, 31, 16, 8, 4, 2
 812#  else
 813      0, 0, 0, 0,
 814      (MIN_BUC_POW2==2 ? 384 : 0), (MIN_BUC_POW2==2 ? 384 : 0), /* 4, 4 */
 815      224, 149, 120, 80, 62, 41, 31, 25, 16, 16, 8, 8, 4, 4, 2, 2
 816#  endif
 817  };
 818
 819/* Shift of the first bucket with the given ordinal inside 2K chunk. */
 820#ifdef IGNORE_SMALL_BAD_FREE
 821#  define BLK_SHIFT(bucket) ( (bucket) < FIRST_BUCKET_WITH_CHECK        \
 822                              ? ((1<<LOG_OF_MIN_ARENA)                  \
 823                                 - BUCKET_SIZE_NO_SURPLUS(bucket) * N_BLKS(bucket)) \
 824                              : blk_shift[bucket])
 825#else
 826#  define BLK_SHIFT(bucket) blk_shift[bucket]
 827#endif 
 828
 829static const u_short blk_shift[LOG_OF_MIN_ARENA * BUCKETS_PER_POW2] =
 830  { 
 831#  if BUCKETS_PER_POW2==1
 832      0, 0,
 833      (MIN_BUC_POW2==2 ? 512 : 0),
 834      256, 128, 64, 64,                 /* 8 to 64 */
 835      16*sizeof(union overhead), 
 836      8*sizeof(union overhead), 
 837      4*sizeof(union overhead), 
 838      2*sizeof(union overhead), 
 839#  else
 840      0, 0, 0, 0,
 841      (MIN_BUC_POW2==2 ? 512 : 0), (MIN_BUC_POW2==2 ? 512 : 0),
 842      256, 260, 128, 128, 64, 80, 64, 48, /* 8 to 96 */
 843      16*sizeof(union overhead), 16*sizeof(union overhead), 
 844      8*sizeof(union overhead), 8*sizeof(union overhead), 
 845      4*sizeof(union overhead), 4*sizeof(union overhead), 
 846      2*sizeof(union overhead), 2*sizeof(union overhead), 
 847#  endif 
 848  };
 849
 850#  define NEEDED_ALIGNMENT 0x800        /* 2k boundaries */
 851#  define WANTED_ALIGNMENT 0x800        /* 2k boundaries */
 852
 853#else  /* !PACK_MALLOC */
 854
 855#  define OV_MAGIC(block,bucket) (block)->ov_magic
 856#  define OV_INDEX(block) (block)->ov_index
 857#  define CHUNK_SHIFT 1
 858#  define MAX_PACKED -1
 859#  define NEEDED_ALIGNMENT MEM_ALIGNBYTES
 860#  define WANTED_ALIGNMENT 0x400        /* 1k boundaries */
 861
 862#endif /* !PACK_MALLOC */
 863
 864#define M_OVERHEAD (sizeof(union overhead) + RMAGIC_SZ) /* overhead at start+end */
 865
 866#ifdef PACK_MALLOC
 867#  define MEM_OVERHEAD(bucket) \
 868  (bucket <= MAX_PACKED ? 0 : M_OVERHEAD)
 869#  ifdef SMALL_BUCKET_VIA_TABLE
 870#    define START_SHIFTS_BUCKET ((MAX_PACKED_POW2 + 1) * BUCKETS_PER_POW2)
 871#    define START_SHIFT MAX_PACKED_POW2
 872#    ifdef BUCKETS_ROOT2                /* Chunks of size 3*2^n. */
 873#      define SIZE_TABLE_MAX 80
 874#    else
 875#      define SIZE_TABLE_MAX 64
 876#    endif 
 877static const char bucket_of[] =
 878  {
 879#    ifdef BUCKETS_ROOT2                /* Chunks of size 3*2^n. */
 880      /* 0 to 15 in 4-byte increments. */
 881      (sizeof(void*) > 4 ? 6 : 5),      /* 4/8, 5-th bucket for better reports */
 882      6,                                /* 8 */
 883      IF_ALIGN_8(8,7), 8,               /* 16/12, 16 */
 884      9, 9, 10, 10,                     /* 24, 32 */
 885      11, 11, 11, 11,                   /* 48 */
 886      12, 12, 12, 12,                   /* 64 */
 887      13, 13, 13, 13,                   /* 80 */
 888      13, 13, 13, 13                    /* 80 */
 889#    else /* !BUCKETS_ROOT2 */
 890      /* 0 to 15 in 4-byte increments. */
 891      (sizeof(void*) > 4 ? 3 : 2),
 892      3, 
 893      4, 4, 
 894      5, 5, 5, 5,
 895      6, 6, 6, 6,
 896      6, 6, 6, 6
 897#    endif /* !BUCKETS_ROOT2 */
 898  };
 899#  else  /* !SMALL_BUCKET_VIA_TABLE */
 900#    define START_SHIFTS_BUCKET MIN_BUCKET
 901#    define START_SHIFT (MIN_BUC_POW2 - 1)
 902#  endif /* !SMALL_BUCKET_VIA_TABLE */
 903#else  /* !PACK_MALLOC */
 904#  define MEM_OVERHEAD(bucket) M_OVERHEAD
 905#  ifdef SMALL_BUCKET_VIA_TABLE
 906#    undef SMALL_BUCKET_VIA_TABLE
 907#  endif 
 908#  define START_SHIFTS_BUCKET MIN_BUCKET
 909#  define START_SHIFT (MIN_BUC_POW2 - 1)
 910#endif /* !PACK_MALLOC */
 911
 912/*
 913 * Big allocations are often of the size 2^n bytes. To make them a
 914 * little bit better, make blocks of size 2^n+pagesize for big n.
 915 */
 916
 917#ifdef TWO_POT_OPTIMIZE
 918
 919#  ifndef PERL_PAGESIZE
 920#    define PERL_PAGESIZE 4096
 921#  endif 
 922#  ifndef FIRST_BIG_POW2
 923#    define FIRST_BIG_POW2 15   /* 32K, 16K is used too often. */
 924#  endif
 925#  define FIRST_BIG_BLOCK (1<<FIRST_BIG_POW2)
 926/* If this value or more, check against bigger blocks. */
 927#  define FIRST_BIG_BOUND (FIRST_BIG_BLOCK - M_OVERHEAD)
 928/* If less than this value, goes into 2^n-overhead-block. */
 929#  define LAST_SMALL_BOUND ((FIRST_BIG_BLOCK>>1) - M_OVERHEAD)
 930
 931#  define POW2_OPTIMIZE_ADJUST(nbytes)                          \
 932   ((nbytes >= FIRST_BIG_BOUND) ? nbytes -= PERL_PAGESIZE : 0)
 933#  define POW2_OPTIMIZE_SURPLUS(bucket)                         \
 934   ((bucket >= FIRST_BIG_POW2 * BUCKETS_PER_POW2) ? PERL_PAGESIZE : 0)
 935
 936#else  /* !TWO_POT_OPTIMIZE */
 937#  define POW2_OPTIMIZE_ADJUST(nbytes)
 938#  define POW2_OPTIMIZE_SURPLUS(bucket) 0
 939#endif /* !TWO_POT_OPTIMIZE */
 940
 941#if defined(HAS_64K_LIMIT) && defined(PERL_CORE)
 942#  define BARK_64K_LIMIT(what,nbytes,size)                              \
 943        if (nbytes > 0xffff) {                                          \
 944                PerlIO_printf(PerlIO_stderr(),                          \
 945                              "%s too large: %lx\n", what, size);       \
 946                my_exit(1);                                             \
 947        }
 948#else /* !HAS_64K_LIMIT || !PERL_CORE */
 949#  define BARK_64K_LIMIT(what,nbytes,size)
 950#endif /* !HAS_64K_LIMIT || !PERL_CORE */
 951
 952#ifndef MIN_SBRK
 953#  define MIN_SBRK 2048
 954#endif 
 955
 956#ifndef FIRST_SBRK
 957#  define FIRST_SBRK (48*1024)
 958#endif 
 959
 960/* Minimal sbrk in percents of what is already alloced. */
 961#ifndef MIN_SBRK_FRAC
 962#  define MIN_SBRK_FRAC 3
 963#endif 
 964
 965#ifndef SBRK_ALLOW_FAILURES
 966#  define SBRK_ALLOW_FAILURES 3
 967#endif 
 968
 969#ifndef SBRK_FAILURE_PRICE
 970#  define SBRK_FAILURE_PRICE 50
 971#endif 
 972
 973static void     morecore        (register int bucket);
 974#  if defined(DEBUGGING)
 975static void     botch           (const char *diag, const char *s, const char *file, int line);
 976#  endif
 977static void     add_to_chain    (void *p, MEM_SIZE size, MEM_SIZE chip);
 978static void*    get_from_chain  (MEM_SIZE size);
 979static void*    get_from_bigger_buckets(int bucket, MEM_SIZE size);
 980static union overhead *getpages (MEM_SIZE needed, int *nblksp, int bucket);
 981static int      getpages_adjacent(MEM_SIZE require);
 982
 983#ifdef PERL_CORE
 984
 985#ifdef I_MACH_CTHREADS
 986#  undef  MUTEX_LOCK
 987#  define MUTEX_LOCK(m)   STMT_START { if (*m) mutex_lock(*m);   } STMT_END
 988#  undef  MUTEX_UNLOCK
 989#  define MUTEX_UNLOCK(m) STMT_START { if (*m) mutex_unlock(*m); } STMT_END
 990#endif
 991
 992#endif  /* defined PERL_CORE */ 
 993
 994#ifndef PTRSIZE
 995#  define PTRSIZE       sizeof(void*)
 996#endif
 997
 998#ifndef BITS_IN_PTR
 999#  define BITS_IN_PTR (8*PTRSIZE)
1000#endif
1001
1002/*
1003 * nextf[i] is the pointer to the next free block of size 2^i.  The
1004 * smallest allocatable block is 8 bytes.  The overhead information
1005 * precedes the data area returned to the user.
1006 */
1007#define NBUCKETS (BITS_IN_PTR*BUCKETS_PER_POW2 + 1)
1008static  union overhead *nextf[NBUCKETS];
1009
1010#if defined(PURIFY) && !defined(USE_PERL_SBRK)
1011#  define USE_PERL_SBRK
1012#endif
1013
1014#ifdef USE_PERL_SBRK
1015# define sbrk(a) Perl_sbrk(a)
1016Malloc_t Perl_sbrk (int size);
1017#else
1018# ifndef HAS_SBRK_PROTO /* <unistd.h> usually takes care of this */
1019extern  Malloc_t sbrk(int);
1020# endif
1021#endif
1022
1023#ifndef MIN_SBRK_FRAC1000       /* Backward compatibility */
1024#  define MIN_SBRK_FRAC1000     (MIN_SBRK_FRAC * 10)
1025#endif
1026
1027#ifndef START_EXTERN_C
1028#  ifdef __cplusplus
1029#    define START_EXTERN_C      extern "C" {
1030#  else
1031#    define START_EXTERN_C
1032#  endif
1033#endif
1034
1035#ifndef END_EXTERN_C
1036#  ifdef __cplusplus
1037#    define END_EXTERN_C                };
1038#  else
1039#    define END_EXTERN_C
1040#  endif
1041#endif
1042
1043#include "malloc_ctl.h"
1044
1045#ifndef NO_MALLOC_DYNAMIC_CFG
1046#  define PERL_MALLOC_OPT_CHARS "FMfAPGdac"
1047
1048#  ifndef FILL_DEAD_DEFAULT
1049#    define FILL_DEAD_DEFAULT   1
1050#  endif
1051#  ifndef FILL_ALIVE_DEFAULT
1052#    define FILL_ALIVE_DEFAULT  1
1053#  endif
1054#  ifndef FILL_CHECK_DEFAULT
1055#    define FILL_CHECK_DEFAULT  1
1056#  endif
1057
1058static IV MallocCfg[MallocCfg_last] = {
1059  FIRST_SBRK,
1060  MIN_SBRK,
1061  MIN_SBRK_FRAC,
1062  SBRK_ALLOW_FAILURES,
1063  SBRK_FAILURE_PRICE,
1064  SBRK_ALLOW_FAILURES * SBRK_FAILURE_PRICE,     /* sbrk_goodness */
1065  FILL_DEAD_DEFAULT,    /* FILL_DEAD */
1066  FILL_ALIVE_DEFAULT,   /* FILL_ALIVE */
1067  FILL_CHECK_DEFAULT,   /* FILL_CHECK */
1068  0,                    /* MallocCfg_skip_cfg_env */
1069  0,                    /* MallocCfg_cfg_env_read */
1070  0,                    /* MallocCfg_emergency_buffer_size */
1071  0,                    /* MallocCfg_emergency_buffer_prepared_size */
1072  0                     /* MallocCfg_emergency_buffer_last_req */
1073};
1074IV *MallocCfg_ptr = MallocCfg;
1075
1076static char* MallocCfgP[MallocCfg_last] = {
1077  0,                    /* MallocCfgP_emergency_buffer */
1078  0,                    /* MallocCfgP_emergency_buffer_prepared */
1079};
1080char **MallocCfgP_ptr = MallocCfgP;
1081
1082#  undef MIN_SBRK
1083#  undef FIRST_SBRK
1084#  undef MIN_SBRK_FRAC1000
1085#  undef SBRK_ALLOW_FAILURES
1086#  undef SBRK_FAILURE_PRICE
1087
1088#  define MIN_SBRK              MallocCfg[MallocCfg_MIN_SBRK]
1089#  define FIRST_SBRK            MallocCfg[MallocCfg_FIRST_SBRK]
1090#  define MIN_SBRK_FRAC1000     MallocCfg[MallocCfg_MIN_SBRK_FRAC1000]
1091#  define SBRK_ALLOW_FAILURES   MallocCfg[MallocCfg_SBRK_ALLOW_FAILURES]
1092#  define SBRK_FAILURE_PRICE    MallocCfg[MallocCfg_SBRK_FAILURE_PRICE]
1093
1094#  define sbrk_goodness         MallocCfg[MallocCfg_sbrk_goodness]
1095
1096#  define emergency_buffer_size MallocCfg[MallocCfg_emergency_buffer_size]
1097#  define emergency_buffer_last_req     MallocCfg[MallocCfg_emergency_buffer_last_req]
1098
1099#  define FILL_DEAD             MallocCfg[MallocCfg_filldead]
1100#  define FILL_ALIVE            MallocCfg[MallocCfg_fillalive]
1101#  define FILL_CHECK_CFG        MallocCfg[MallocCfg_fillcheck]
1102#  define FILL_CHECK            (FILL_DEAD && FILL_CHECK_CFG)
1103
1104#  define emergency_buffer      MallocCfgP[MallocCfgP_emergency_buffer]
1105#  define emergency_buffer_prepared     MallocCfgP[MallocCfgP_emergency_buffer_prepared]
1106
1107#else   /* defined(NO_MALLOC_DYNAMIC_CFG) */
1108
1109#  define FILL_DEAD     1
1110#  define FILL_ALIVE    1
1111#  define FILL_CHECK    1
1112static int sbrk_goodness = SBRK_ALLOW_FAILURES * SBRK_FAILURE_PRICE;
1113
1114#  define NO_PERL_MALLOC_ENV
1115
1116#endif
1117
1118#ifdef DEBUGGING_MSTATS
1119/*
1120 * nmalloc[i] is the difference between the number of mallocs and frees
1121 * for a given block size.
1122 */
1123static  u_int nmalloc[NBUCKETS];
1124static  u_int sbrk_slack;
1125static  u_int start_slack;
1126#else   /* !( defined DEBUGGING_MSTATS ) */
1127#  define sbrk_slack    0
1128#endif
1129
1130static  u_int goodsbrk;
1131
1132#ifdef PERL_EMERGENCY_SBRK
1133
1134#  ifndef BIG_SIZE
1135#    define BIG_SIZE (1<<16)            /* 64K */
1136#  endif
1137
1138#  ifdef NO_MALLOC_DYNAMIC_CFG
1139static MEM_SIZE emergency_buffer_size;
1140        /* 0 if the last request for more memory succeeded.
1141           Otherwise the size of the failing request. */
1142static MEM_SIZE emergency_buffer_last_req;
1143static char *emergency_buffer;
1144static char *emergency_buffer_prepared;
1145#  endif
1146
1147#  ifndef emergency_sbrk_croak
1148#    define emergency_sbrk_croak        croak2
1149#  endif
1150
1151#  ifdef PERL_CORE
1152static char *
1153perl_get_emergency_buffer(IV *size)
1154{
1155    dTHX;
1156    /* First offense, give a possibility to recover by dieing. */
1157    /* No malloc involved here: */
1158    SV *sv;
1159    char *pv;
1160    GV **gvp = (GV**)hv_fetchs(PL_defstash, "^M", FALSE);
1161
1162    if (!gvp) gvp = (GV**)hv_fetchs(PL_defstash, "\015", FALSE);
1163    if (!gvp || !(sv = GvSV(*gvp)) || !SvPOK(sv) 
1164        || (SvLEN(sv) < (1<<LOG_OF_MIN_ARENA) - M_OVERHEAD))
1165        return NULL;            /* Now die die die... */
1166    /* Got it, now detach SvPV: */
1167    pv = SvPV_nolen(sv);
1168    /* Check alignment: */
1169    if ((PTR2UV(pv) - sizeof(union overhead)) & (NEEDED_ALIGNMENT - 1)) {
1170        PerlIO_puts(PerlIO_stderr(),"Bad alignment of $^M!\n");
1171        return NULL;            /* die die die */
1172    }
1173
1174    SvPOK_off(sv);
1175    SvPV_set(sv, NULL);
1176    SvCUR_set(sv, 0);
1177    SvLEN_set(sv, 0);
1178    *size = malloced_size(pv) + M_OVERHEAD;
1179    return pv - sizeof(union overhead);
1180}
1181#    define PERL_GET_EMERGENCY_BUFFER(p)        perl_get_emergency_buffer(p)
1182#  else
1183#    define PERL_GET_EMERGENCY_BUFFER(p)        NULL
1184#  endif        /* defined PERL_CORE */
1185
1186#  ifndef NO_MALLOC_DYNAMIC_CFG
1187static char *
1188get_emergency_buffer(IV *size)
1189{
1190    char *pv = emergency_buffer_prepared;
1191
1192    *size = MallocCfg[MallocCfg_emergency_buffer_prepared_size];
1193    emergency_buffer_prepared = 0;
1194    MallocCfg[MallocCfg_emergency_buffer_prepared_size] = 0;
1195    return pv;
1196}
1197
1198/* Returns 0 on success, -1 on bad alignment, -2 if not implemented */
1199int
1200set_emergency_buffer(char *b, IV size)
1201{
1202    if (PTR2UV(b) & (NEEDED_ALIGNMENT - 1))
1203        return -1;
1204    if (MallocCfg[MallocCfg_emergency_buffer_prepared_size])
1205        add_to_chain((void*)emergency_buffer_prepared,
1206                     MallocCfg[MallocCfg_emergency_buffer_prepared_size], 0);
1207    emergency_buffer_prepared = b;
1208    MallocCfg[MallocCfg_emergency_buffer_prepared_size] = size;
1209    return 0;
1210}
1211#    define GET_EMERGENCY_BUFFER(p)     get_emergency_buffer(p)
1212#  else         /* NO_MALLOC_DYNAMIC_CFG */
1213#    define GET_EMERGENCY_BUFFER(p)     NULL
1214int
1215set_emergency_buffer(char *b, IV size)
1216{
1217    return -1;
1218}
1219#  endif
1220
1221static Malloc_t
1222emergency_sbrk(MEM_SIZE size)
1223{
1224    MEM_SIZE rsize = (((size - 1)>>LOG_OF_MIN_ARENA) + 1)<<LOG_OF_MIN_ARENA;
1225
1226    if (size >= BIG_SIZE
1227        && (!emergency_buffer_last_req ||
1228            (size < (MEM_SIZE)emergency_buffer_last_req))) {
1229        /* Give the possibility to recover, but avoid an infinite cycle. */
1230        MALLOC_UNLOCK;
1231        emergency_buffer_last_req = size;
1232        emergency_sbrk_croak("Out of memory during \"large\" request for %"UVuf" bytes, total sbrk() is %"UVuf" bytes", (UV)size, (UV)(goodsbrk + sbrk_slack));
1233    }
1234
1235    if ((MEM_SIZE)emergency_buffer_size >= rsize) {
1236        char *old = emergency_buffer;
1237        
1238        emergency_buffer_size -= rsize;
1239        emergency_buffer += rsize;
1240        return old;
1241    } else {            
1242        /* First offense, give a possibility to recover by dieing. */
1243        /* No malloc involved here: */
1244        IV Size;
1245        char *pv = GET_EMERGENCY_BUFFER(&Size);
1246        int have = 0;
1247
1248        if (emergency_buffer_size) {
1249            add_to_chain(emergency_buffer, emergency_buffer_size, 0);
1250            emergency_buffer_size = 0;
1251            emergency_buffer = NULL;
1252            have = 1;
1253        }
1254
1255        if (!pv)
1256            pv = PERL_GET_EMERGENCY_BUFFER(&Size);
1257        if (!pv) {
1258            if (have)
1259                goto do_croak;
1260            return (char *)-1;          /* Now die die die... */
1261        }
1262
1263        /* Check alignment: */
1264        if (PTR2UV(pv) & (NEEDED_ALIGNMENT - 1)) {
1265            dTHX;
1266
1267            PerlIO_puts(PerlIO_stderr(),"Bad alignment of $^M!\n");
1268            return (char *)-1;          /* die die die */
1269        }
1270
1271        emergency_buffer = pv;
1272        emergency_buffer_size = Size;
1273    }
1274  do_croak:
1275    MALLOC_UNLOCK;
1276    emergency_sbrk_croak("Out of memory during request for %"UVuf" bytes, total sbrk() is %"UVuf" bytes", (UV)size, (UV)(goodsbrk + sbrk_slack));
1277    /* NOTREACHED */
1278    return NULL;
1279}
1280
1281#else /*  !defined(PERL_EMERGENCY_SBRK) */
1282#  define emergency_sbrk(size)  -1
1283#endif  /* defined PERL_EMERGENCY_SBRK */
1284
1285static void
1286write2(const char *mess)
1287{
1288  write(2, mess, strlen(mess));
1289}
1290
1291#ifdef DEBUGGING
1292#undef ASSERT
1293#define ASSERT(p,diag)   if (!(p)) botch(diag,STRINGIFY(p),__FILE__,__LINE__);
1294
1295static void
1296botch(const char *diag, const char *s, const char *file, int line)
1297{
1298    dVAR;
1299    dTHX;
1300    if (!(PERL_MAYBE_ALIVE && PERL_GET_THX))
1301        goto do_write;
1302    else {
1303        if (PerlIO_printf(PerlIO_stderr(),
1304                          "assertion botched (%s?): %s %s:%d\n",
1305                          diag, s, file, line) != 0) {
1306         do_write:              /* Can be initializing interpreter */
1307            write2("assertion botched (");
1308            write2(diag);
1309            write2("?): ");
1310            write2(s);
1311            write2(" (");
1312            write2(file);
1313            write2(":");
1314            {
1315              char linebuf[10];
1316              char *s = linebuf + sizeof(linebuf) - 1;
1317              int n = line;
1318              *s = 0;
1319              do {
1320                *--s = '0' + (n % 10);
1321              } while (n /= 10);
1322              write2(s);
1323            }
1324            write2(")\n");
1325        }
1326        PerlProc_abort();
1327    }
1328}
1329#else
1330#define ASSERT(p, diag)
1331#endif
1332
1333#ifdef MALLOC_FILL
1334/* Fill should be long enough to cover long */
1335static void
1336fill_pat_4bytes(unsigned char *s, size_t nbytes, const unsigned char *fill)
1337{
1338    unsigned char *e = s + nbytes;
1339    long *lp;
1340    const long lfill = *(long*)fill;
1341
1342    if (PTR2UV(s) & (sizeof(long)-1)) {         /* Align the pattern */
1343        int shift = sizeof(long) - (PTR2UV(s) & (sizeof(long)-1));
1344        unsigned const char *f = fill + sizeof(long) - shift;
1345        unsigned char *e1 = s + shift;
1346
1347        while (s < e1)
1348            *s++ = *f++;
1349    }
1350    lp = (long*)s;
1351    while ((unsigned char*)(lp + 1) <= e)
1352        *lp++ = lfill;
1353    s = (unsigned char*)lp;
1354    while (s < e)
1355        *s++ = *fill++;
1356}
1357/* Just malloc()ed */
1358static const unsigned char fill_feedadad[] =
1359 {0xFE, 0xED, 0xAD, 0xAD, 0xFE, 0xED, 0xAD, 0xAD,
1360  0xFE, 0xED, 0xAD, 0xAD, 0xFE, 0xED, 0xAD, 0xAD};
1361/* Just free()ed */
1362static const unsigned char fill_deadbeef[] =
1363 {0xDE, 0xAD, 0xBE, 0xEF, 0xDE, 0xAD, 0xBE, 0xEF,
1364  0xDE, 0xAD, 0xBE, 0xEF, 0xDE, 0xAD, 0xBE, 0xEF};
1365#  define FILL_DEADBEEF(s, n)   \
1366        (void)(FILL_DEAD?  (fill_pat_4bytes((s), (n), fill_deadbeef), 0) : 0)
1367#  define FILL_FEEDADAD(s, n)   \
1368        (void)(FILL_ALIVE? (fill_pat_4bytes((s), (n), fill_feedadad), 0) : 0)
1369#else
1370#  define FILL_DEADBEEF(s, n)   ((void)0)
1371#  define FILL_FEEDADAD(s, n)   ((void)0)
1372#  undef MALLOC_FILL_CHECK
1373#endif
1374
1375#ifdef MALLOC_FILL_CHECK
1376static int
1377cmp_pat_4bytes(unsigned char *s, size_t nbytes, const unsigned char *fill)
1378{
1379    unsigned char *e = s + nbytes;
1380    long *lp;
1381    const long lfill = *(long*)fill;
1382
1383    if (PTR2UV(s) & (sizeof(long)-1)) {         /* Align the pattern */
1384        int shift = sizeof(long) - (PTR2UV(s) & (sizeof(long)-1));
1385        unsigned const char *f = fill + sizeof(long) - shift;
1386        unsigned char *e1 = s + shift;
1387
1388        while (s < e1)
1389            if (*s++ != *f++)
1390                return 1;
1391    }
1392    lp = (long*)s;
1393    while ((unsigned char*)(lp + 1) <= e)
1394        if (*lp++ != lfill)
1395            return 1;
1396    s = (unsigned char*)lp;
1397    while (s < e)
1398        if (*s++ != *fill++)
1399            return 1;
1400    return 0;
1401}
1402#  define FILLCHECK_DEADBEEF(s, n)                                      \
1403        ASSERT(!FILL_CHECK || !cmp_pat_4bytes(s, n, fill_deadbeef),     \
1404               "free()ed/realloc()ed-away memory was overwritten")
1405#else
1406#  define FILLCHECK_DEADBEEF(s, n)      ((void)0)
1407#endif
1408
1409int
1410S_ajust_size_and_find_bucket(size_t *nbytes_p)
1411{
1412        MEM_SIZE shiftr;
1413        int bucket;
1414        size_t nbytes = *nbytes_p;
1415
1416        /*
1417         * Convert amount of memory requested into
1418         * closest block size stored in hash buckets
1419         * which satisfies request.  Account for
1420         * space used per block for accounting.
1421         */
1422#ifdef PACK_MALLOC
1423#  ifdef SMALL_BUCKET_VIA_TABLE
1424        if (nbytes == 0)
1425            bucket = MIN_BUCKET;
1426        else if (nbytes <= SIZE_TABLE_MAX) {
1427            bucket = bucket_of[(nbytes - 1) >> BUCKET_TABLE_SHIFT];
1428        } else
1429#  else
1430        if (nbytes == 0)
1431            nbytes = 1;
1432        if (nbytes <= MAX_POW2_ALGO) goto do_shifts;
1433        else
1434#  endif
1435#endif 
1436        {
1437            POW2_OPTIMIZE_ADJUST(nbytes);
1438            nbytes += M_OVERHEAD;
1439            nbytes = (nbytes + 3) &~ 3; 
1440#if defined(PACK_MALLOC) && !defined(SMALL_BUCKET_VIA_TABLE)
1441          do_shifts:
1442#endif
1443            shiftr = (nbytes - 1) >> START_SHIFT;
1444            bucket = START_SHIFTS_BUCKET;
1445            /* apart from this loop, this is O(1) */
1446            while (shiftr >>= 1)
1447                bucket += BUCKETS_PER_POW2;
1448        }
1449        *nbytes_p = nbytes;
1450        return bucket;
1451}
1452
1453Malloc_t
1454Perl_malloc(size_t nbytes)
1455{
1456        dVAR;
1457        register union overhead *p;
1458        register int bucket;
1459
1460#if defined(DEBUGGING) || defined(RCHECK)
1461        MEM_SIZE size = nbytes;
1462#endif
1463
1464        BARK_64K_LIMIT("Allocation",nbytes,nbytes);
1465#ifdef DEBUGGING
1466        if ((long)nbytes < 0)
1467            croak("%s", "panic: malloc");
1468#endif
1469
1470        bucket = S_ajust_size_and_find_bucket(&nbytes);
1471        MALLOC_LOCK;
1472        /*
1473         * If nothing in hash bucket right now,
1474         * request more memory from the system.
1475         */
1476        if (nextf[bucket] == NULL)    
1477                morecore(bucket);
1478        if ((p = nextf[bucket]) == NULL) {
1479                MALLOC_UNLOCK;
1480#ifdef PERL_CORE
1481                {
1482                    dTHX;
1483                    if (!PL_nomemok) {
1484#if defined(PLAIN_MALLOC) && defined(NO_FANCY_MALLOC)
1485                        PerlIO_puts(PerlIO_stderr(),"Out of memory!\n");
1486#else
1487                        char buff[80];
1488                        char *eb = buff + sizeof(buff) - 1;
1489                        char *s = eb;
1490                        size_t n = nbytes;
1491
1492                        PerlIO_puts(PerlIO_stderr(),"Out of memory during request for ");
1493#if defined(DEBUGGING) || defined(RCHECK)
1494                        n = size;
1495#endif
1496                        *s = 0;                 
1497                        do {
1498                            *--s = '0' + (n % 10);
1499                        } while (n /= 10);
1500                        PerlIO_puts(PerlIO_stderr(),s);
1501                        PerlIO_puts(PerlIO_stderr()," bytes, total sbrk() is ");
1502                        s = eb;
1503                        n = goodsbrk + sbrk_slack;
1504                        do {
1505                            *--s = '0' + (n % 10);
1506                        } while (n /= 10);
1507                        PerlIO_puts(PerlIO_stderr(),s);
1508                        PerlIO_puts(PerlIO_stderr()," bytes!\n");
1509#endif /* defined(PLAIN_MALLOC) && defined(NO_FANCY_MALLOC) */
1510                        my_exit(1);
1511                    }
1512                }
1513#endif
1514                return (NULL);
1515        }
1516
1517        /* remove from linked list */
1518#ifdef DEBUGGING
1519        if ( (PTR2UV(p) & (MEM_ALIGNBYTES - 1))
1520                                                /* Can't get this low */
1521             || (p && PTR2UV(p) < (1<<LOG_OF_MIN_ARENA)) ) {
1522            dTHX;
1523            PerlIO_printf(PerlIO_stderr(),
1524                          "Unaligned pointer in the free chain 0x%"UVxf"\n",
1525                          PTR2UV(p));
1526        }
1527        if ( (PTR2UV(p->ov_next) & (MEM_ALIGNBYTES - 1))
1528             || (p->ov_next && PTR2UV(p->ov_next) < (1<<LOG_OF_MIN_ARENA)) ) {
1529            dTHX;
1530            PerlIO_printf(PerlIO_stderr(),
1531                          "Unaligned \"next\" pointer in the free "
1532                          "chain 0x%"UVxf" at 0x%"UVxf"\n",
1533                          PTR2UV(p->ov_next), PTR2UV(p));
1534        }
1535#endif
1536        nextf[bucket] = p->ov_next;
1537
1538        MALLOC_UNLOCK;
1539
1540        DEBUG_m(PerlIO_printf(Perl_debug_log,
1541                              "0x%"UVxf": (%05lu) malloc %ld bytes\n",
1542                              PTR2UV((Malloc_t)(p + CHUNK_SHIFT)), (unsigned long)(PL_an++),
1543                              (long)size));
1544
1545        FILLCHECK_DEADBEEF((unsigned char*)(p + CHUNK_SHIFT),
1546                           BUCKET_SIZE_REAL(bucket) + RMAGIC_SZ);
1547
1548#ifdef IGNORE_SMALL_BAD_FREE
1549        if (bucket >= FIRST_BUCKET_WITH_CHECK)
1550#endif 
1551            OV_MAGIC(p, bucket) = MAGIC;
1552#ifndef PACK_MALLOC
1553        OV_INDEX(p) = bucket;
1554#endif
1555#ifdef RCHECK
1556        /*
1557         * Record allocated size of block and
1558         * bound space with magic numbers.
1559         */
1560        p->ov_rmagic = RMAGIC;
1561        if (bucket <= MAX_SHORT_BUCKET) {
1562            int i;
1563            
1564            nbytes = size + M_OVERHEAD; 
1565            p->ov_size = nbytes - 1;
1566            if ((i = nbytes & (RMAGIC_SZ-1))) {
1567                i = RMAGIC_SZ - i;
1568                while (i--) /* nbytes - RMAGIC_SZ is end of alloced area */
1569                    ((caddr_t)p + nbytes - RMAGIC_SZ)[i] = RMAGIC_C;
1570            }
1571            /* Same at RMAGIC_SZ-aligned RMAGIC */
1572            nbytes = (nbytes + RMAGIC_SZ - 1) & ~(RMAGIC_SZ - 1);
1573            ((u_int *)((caddr_t)p + nbytes))[-1] = RMAGIC;
1574        }
1575        FILL_FEEDADAD((unsigned char *)(p + CHUNK_SHIFT), size);
1576#endif
1577        return ((Malloc_t)(p + CHUNK_SHIFT));
1578}
1579
1580static char *last_sbrk_top;
1581static char *last_op;                   /* This arena can be easily extended. */
1582static MEM_SIZE sbrked_remains;
1583
1584#ifdef DEBUGGING_MSTATS
1585static int sbrks;
1586#endif 
1587
1588struct chunk_chain_s {
1589    struct chunk_chain_s *next;
1590    MEM_SIZE size;
1591};
1592static struct chunk_chain_s *chunk_chain;
1593static int n_chunks;
1594static char max_bucket;
1595
1596/* Cutoff a piece of one of the chunks in the chain.  Prefer smaller chunk. */
1597static void *
1598get_from_chain(MEM_SIZE size)
1599{
1600    struct chunk_chain_s *elt = chunk_chain, **oldp = &chunk_chain;
1601    struct chunk_chain_s **oldgoodp = NULL;
1602    long min_remain = LONG_MAX;
1603
1604    while (elt) {
1605        if (elt->size >= size) {
1606            long remains = elt->size - size;
1607            if (remains >= 0 && remains < min_remain) {
1608                oldgoodp = oldp;
1609                min_remain = remains;
1610            }
1611            if (remains == 0) {
1612                break;
1613            }
1614        }
1615        oldp = &( elt->next );
1616        elt = elt->next;
1617    }
1618    if (!oldgoodp) return NULL;
1619    if (min_remain) {
1620        void *ret = *oldgoodp;
1621        struct chunk_chain_s *next = (*oldgoodp)->next;
1622        
1623        *oldgoodp = (struct chunk_chain_s *)((char*)ret + size);
1624        (*oldgoodp)->size = min_remain;
1625        (*oldgoodp)->next = next;
1626        return ret;
1627    } else {
1628        void *ret = *oldgoodp;
1629        *oldgoodp = (*oldgoodp)->next;
1630        n_chunks--;
1631        return ret;
1632    }
1633}
1634
1635static void
1636add_to_chain(void *p, MEM_SIZE size, MEM_SIZE chip)
1637{
1638    struct chunk_chain_s *next = chunk_chain;
1639    char *cp = (char*)p;
1640    
1641    cp += chip;
1642    chunk_chain = (struct chunk_chain_s *)cp;
1643    chunk_chain->size = size - chip;
1644    chunk_chain->next = next;
1645    n_chunks++;
1646}
1647
1648static void *
1649get_from_bigger_buckets(int bucket, MEM_SIZE size)
1650{
1651    int price = 1;
1652    static int bucketprice[NBUCKETS];
1653    while (bucket <= max_bucket) {
1654        /* We postpone stealing from bigger buckets until we want it
1655           often enough. */
1656        if (nextf[bucket] && bucketprice[bucket]++ >= price) {
1657            /* Steal it! */
1658            void *ret = (void*)(nextf[bucket] - 1 + CHUNK_SHIFT);
1659            bucketprice[bucket] = 0;
1660            if (((char*)nextf[bucket]) - M_OVERHEAD == last_op) {
1661                last_op = NULL;         /* Disable optimization */
1662            }
1663            nextf[bucket] = nextf[bucket]->ov_next;
1664#ifdef DEBUGGING_MSTATS
1665            nmalloc[bucket]--;
1666            start_slack -= M_OVERHEAD;
1667#endif 
1668            add_to_chain(ret, (BUCKET_SIZE_NO_SURPLUS(bucket) +
1669                               POW2_OPTIMIZE_SURPLUS(bucket)), 
1670                         size);
1671            return ret;
1672        }
1673        bucket++;
1674    }
1675    return NULL;
1676}
1677
1678static union overhead *
1679getpages(MEM_SIZE needed, int *nblksp, int bucket)
1680{
1681    dVAR;
1682    /* Need to do (possibly expensive) system call. Try to
1683       optimize it for rare calling. */
1684    MEM_SIZE require = needed - sbrked_remains;
1685    char *cp;
1686    union overhead *ovp;
1687    MEM_SIZE slack = 0;
1688
1689    if (sbrk_goodness > 0) {
1690        if (!last_sbrk_top && require < (MEM_SIZE)FIRST_SBRK) 
1691            require = FIRST_SBRK;
1692        else if (require < (MEM_SIZE)MIN_SBRK) require = MIN_SBRK;
1693
1694        if (require < goodsbrk * MIN_SBRK_FRAC1000 / 1000)
1695            require = goodsbrk * MIN_SBRK_FRAC1000 / 1000;
1696        require = ((require - 1 + MIN_SBRK) / MIN_SBRK) * MIN_SBRK;
1697    } else {
1698        require = needed;
1699        last_sbrk_top = 0;
1700        sbrked_remains = 0;
1701    }
1702
1703    DEBUG_m(PerlIO_printf(Perl_debug_log, 
1704                          "sbrk(%ld) for %ld-byte-long arena\n",
1705                          (long)require, (long) needed));
1706    cp = (char *)sbrk(require);
1707#ifdef DEBUGGING_MSTATS
1708    sbrks++;
1709#endif 
1710    if (cp == last_sbrk_top) {
1711        /* Common case, anything is fine. */
1712        sbrk_goodness++;
1713        ovp = (union overhead *) (cp - sbrked_remains);
1714        last_op = cp - sbrked_remains;
1715        sbrked_remains = require - (needed - sbrked_remains);
1716    } else if (cp == (char *)-1) { /* no more room! */
1717        ovp = (union overhead *)emergency_sbrk(needed);
1718        if (ovp == (union overhead *)-1)
1719            return 0;
1720        if (((char*)ovp) > last_op) {   /* Cannot happen with current emergency_sbrk() */
1721            last_op = 0;
1722        }
1723        return ovp;
1724    } else {                    /* Non-continuous or first sbrk(). */
1725        long add = sbrked_remains;
1726        char *newcp;
1727
1728        if (sbrked_remains) {   /* Put rest into chain, we
1729                                   cannot use it right now. */
1730            add_to_chain((void*)(last_sbrk_top - sbrked_remains),
1731                         sbrked_remains, 0);
1732        }
1733
1734        /* Second, check alignment. */
1735        slack = 0;
1736
1737#if !defined(atarist) && !defined(__MINT__) /* on the atari we dont have to worry about this */
1738#  ifndef I286  /* The sbrk(0) call on the I286 always returns the next segment */
1739        /* WANTED_ALIGNMENT may be more than NEEDED_ALIGNMENT, but this may
1740           improve performance of memory access. */
1741        if (PTR2UV(cp) & (WANTED_ALIGNMENT - 1)) { /* Not aligned. */
1742            slack = WANTED_ALIGNMENT - (PTR2UV(cp) & (WANTED_ALIGNMENT - 1));
1743            add += slack;
1744        }
1745#  endif
1746#endif /* !atarist && !MINT */
1747                
1748        if (add) {
1749            DEBUG_m(PerlIO_printf(Perl_debug_log, 
1750                                  "sbrk(%ld) to fix non-continuous/off-page sbrk:\n\t%ld for alignement,\t%ld were assumed to come from the tail of the previous sbrk\n",
1751                                  (long)add, (long) slack,
1752                                  (long) sbrked_remains));
1753            newcp = (char *)sbrk(add);
1754#if defined(DEBUGGING_MSTATS)
1755            sbrks++;
1756            sbrk_slack += add;
1757#endif
1758            if (newcp != cp + require) {
1759                /* Too bad: even rounding sbrk() is not continuous.*/
1760                DEBUG_m(PerlIO_printf(Perl_debug_log, 
1761                                      "failed to fix bad sbrk()\n"));
1762#ifdef PACK_MALLOC
1763                if (slack) {
1764                    MALLOC_UNLOCK;
1765                    fatalcroak("panic: Off-page sbrk\n");
1766                }
1767#endif
1768                if (sbrked_remains) {
1769                    /* Try again. */
1770#if defined(DEBUGGING_MSTATS)
1771                    sbrk_slack += require;
1772#endif
1773                    require = needed;
1774                    DEBUG_m(PerlIO_printf(Perl_debug_log, 
1775                                          "straight sbrk(%ld)\n",
1776                                          (long)require));
1777                    cp = (char *)sbrk(require);
1778#ifdef DEBUGGING_MSTATS
1779                    sbrks++;
1780#endif 
1781                    if (cp == (char *)-1)
1782                        return 0;
1783                }
1784                sbrk_goodness = -1;     /* Disable optimization!
1785                                   Continue with not-aligned... */
1786            } else {
1787                cp += slack;
1788                require += sbrked_remains;
1789            }
1790        }
1791
1792        if (last_sbrk_top) {
1793            sbrk_goodness -= SBRK_FAILURE_PRICE;
1794        }
1795
1796        ovp = (union overhead *) cp;
1797        /*
1798         * Round up to minimum allocation size boundary
1799         * and deduct from block count to reflect.
1800         */
1801
1802#  if NEEDED_ALIGNMENT > MEM_ALIGNBYTES
1803        if (PTR2UV(ovp) & (NEEDED_ALIGNMENT - 1))
1804            fatalcroak("Misalignment of sbrk()\n");
1805        else
1806#  endif
1807#ifndef I286    /* Again, this should always be ok on an 80286 */
1808        if (PTR2UV(ovp) & (MEM_ALIGNBYTES - 1)) {
1809            DEBUG_m(PerlIO_printf(Perl_debug_log, 
1810                                  "fixing sbrk(): %d bytes off machine alignement\n",
1811                                  (int)(PTR2UV(ovp) & (MEM_ALIGNBYTES - 1))));
1812            ovp = INT2PTR(union overhead *,(PTR2UV(ovp) + MEM_ALIGNBYTES) &
1813                                     (MEM_ALIGNBYTES - 1));
1814            (*nblksp)--;
1815# if defined(DEBUGGING_MSTATS)
1816            /* This is only approx. if TWO_POT_OPTIMIZE: */
1817            sbrk_slack += (1 << (bucket >> BUCKET_POW2_SHIFT));
1818# endif
1819        }
1820#endif
1821        ;                               /* Finish "else" */
1822        sbrked_remains = require - needed;
1823        last_op = cp;
1824    }
1825#if !defined(PLAIN_MALLOC) && !defined(NO_FANCY_MALLOC)
1826    emergency_buffer_last_req = 0;
1827#endif
1828    last_sbrk_top = cp + require;
1829#ifdef DEBUGGING_MSTATS
1830    goodsbrk += require;
1831#endif  
1832    return ovp;
1833}
1834
1835static int
1836getpages_adjacent(MEM_SIZE require)
1837{           
1838    if (require <= sbrked_remains) {
1839        sbrked_remains -= require;
1840    } else {
1841        char *cp;
1842
1843        require -= sbrked_remains;
1844        /* We do not try to optimize sbrks here, we go for place. */
1845        cp = (char*) sbrk(require);
1846#ifdef DEBUGGING_MSTATS
1847        sbrks++;
1848        goodsbrk += require;
1849#endif 
1850        if (cp == last_sbrk_top) {
1851            sbrked_remains = 0;
1852            last_sbrk_top = cp + require;
1853        } else {
1854            if (cp == (char*)-1) {      /* Out of memory */
1855#ifdef DEBUGGING_MSTATS
1856                goodsbrk -= require;
1857#endif
1858                return 0;
1859            }
1860            /* Report the failure: */
1861            if (sbrked_remains)
1862                add_to_chain((void*)(last_sbrk_top - sbrked_remains),
1863                             sbrked_remains, 0);
1864            add_to_chain((void*)cp, require, 0);
1865            sbrk_goodness -= SBRK_FAILURE_PRICE;
1866            sbrked_remains = 0;
1867            last_sbrk_top = 0;
1868            last_op = 0;
1869            return 0;
1870        }
1871    }
1872            
1873    return 1;
1874}
1875
1876/*
1877 * Allocate more memory to the indicated bucket.
1878 */
1879static void
1880morecore(register int bucket)
1881{
1882        dVAR;
1883        register union overhead *ovp;
1884        register int rnu;       /* 2^rnu bytes will be requested */
1885        int nblks;              /* become nblks blocks of the desired size */
1886        register MEM_SIZE siz, needed;
1887        static int were_called = 0;
1888
1889        if (nextf[bucket])
1890                return;
1891#ifndef NO_PERL_MALLOC_ENV
1892        if (!were_called) {
1893            /* It's the our first time.  Initialize ourselves */
1894            were_called = 1;    /* Avoid a loop */
1895            if (!MallocCfg[MallocCfg_skip_cfg_env]) {
1896                char *s = getenv("PERL_MALLOC_OPT"), *t = s, *off;
1897                const char *opts = PERL_MALLOC_OPT_CHARS;
1898                int changed = 0;
1899
1900                while ( t && t[0] && t[1] == '='
1901                        && ((off = strchr(opts, *t))) ) {
1902                    IV val = 0;
1903
1904                    t += 2;
1905                    while (*t <= '9' && *t >= '0')
1906                        val = 10*val + *t++ - '0';
1907                    if (!*t || *t == ';') {
1908                        if (MallocCfg[off - opts] != val)
1909                            changed = 1;
1910                        MallocCfg[off - opts] = val;
1911                        if (*t)
1912                            t++;
1913                    }
1914                }
1915                if (t && *t) {
1916                    write2("Unrecognized part of PERL_MALLOC_OPT: \"");
1917                    write2(t);
1918                    write2("\"\n");
1919                }
1920                if (changed)
1921                    MallocCfg[MallocCfg_cfg_env_read] = 1;
1922            }
1923        }
1924#endif
1925        if (bucket == sizeof(MEM_SIZE)*8*BUCKETS_PER_POW2) {
1926            MALLOC_UNLOCK;
1927            croak("%s", "Out of memory during ridiculously large request");
1928        }
1929        if (bucket > max_bucket)
1930            max_bucket = bucket;
1931
1932        rnu = ( (bucket <= (LOG_OF_MIN_ARENA << BUCKET_POW2_SHIFT)) 
1933                ? LOG_OF_MIN_ARENA 
1934                : (bucket >> BUCKET_POW2_SHIFT) );
1935        /* This may be overwritten later: */
1936        nblks = 1 << (rnu - (bucket >> BUCKET_POW2_SHIFT)); /* how many blocks to get */
1937        needed = ((MEM_SIZE)1 << rnu) + POW2_OPTIMIZE_SURPLUS(bucket);
1938        if (nextf[rnu << BUCKET_POW2_SHIFT]) { /* 2048b bucket. */
1939            ovp = nextf[rnu << BUCKET_POW2_SHIFT] - 1 + CHUNK_SHIFT;
1940            nextf[rnu << BUCKET_POW2_SHIFT]
1941                = nextf[rnu << BUCKET_POW2_SHIFT]->ov_next;
1942#ifdef DEBUGGING_MSTATS
1943            nmalloc[rnu << BUCKET_POW2_SHIFT]--;
1944            start_slack -= M_OVERHEAD;
1945#endif 
1946            DEBUG_m(PerlIO_printf(Perl_debug_log, 
1947                                  "stealing %ld bytes from %ld arena\n",
1948                                  (long) needed, (long) rnu << BUCKET_POW2_SHIFT));
1949        } else if (chunk_chain 
1950                   && (ovp = (union overhead*) get_from_chain(needed))) {
1951            DEBUG_m(PerlIO_printf(Perl_debug_log, 
1952                                  "stealing %ld bytes from chain\n",
1953                                  (long) needed));
1954        } else if ( (ovp = (union overhead*)
1955                     get_from_bigger_buckets((rnu << BUCKET_POW2_SHIFT) + 1,
1956                                             needed)) ) {
1957            DEBUG_m(PerlIO_printf(Perl_debug_log, 
1958                                  "stealing %ld bytes from bigger buckets\n",
1959                                  (long) needed));
1960        } else if (needed <= sbrked_remains) {
1961            ovp = (union overhead *)(last_sbrk_top - sbrked_remains);
1962            sbrked_remains -= needed;
1963            last_op = (char*)ovp;
1964        } else 
1965            ovp = getpages(needed, &nblks, bucket);
1966
1967        if (!ovp)
1968            return;
1969        FILL_DEADBEEF((unsigned char*)ovp, needed);
1970
1971        /*
1972         * Add new memory allocated to that on
1973         * free list for this hash bucket.
1974         */
1975        siz = BUCKET_SIZE_NO_SURPLUS(bucket); /* No surplus if nblks > 1 */
1976#ifdef PACK_MALLOC
1977        *(u_char*)ovp = bucket; /* Fill index. */
1978        if (bucket <= MAX_PACKED) {
1979            ovp = (union overhead *) ((char*)ovp + BLK_SHIFT(bucket));
1980            nblks = N_BLKS(bucket);
1981#  ifdef DEBUGGING_MSTATS
1982            start_slack += BLK_SHIFT(bucket);
1983#  endif
1984        } else if (bucket < LOG_OF_MIN_ARENA * BUCKETS_PER_POW2) {
1985            ovp = (union overhead *) ((char*)ovp + BLK_SHIFT(bucket));
1986            siz -= sizeof(union overhead);
1987        } else ovp++;           /* One chunk per block. */
1988#endif /* PACK_MALLOC */
1989        nextf[bucket] = ovp;
1990#ifdef DEBUGGING_MSTATS
1991        nmalloc[bucket] += nblks;
1992        if (bucket > MAX_PACKED) {
1993            start_slack += M_OVERHEAD * nblks;
1994        }
1995#endif 
1996
1997        while (--nblks > 0) {
1998                ovp->ov_next = (union overhead *)((caddr_t)ovp + siz);
1999                ovp = (union overhead *)((caddr_t)ovp + siz);
2000        }
2001        /* Not all sbrks return zeroed memory.*/
2002        ovp->ov_next = (union overhead *)NULL;
2003#ifdef PACK_MALLOC
2004        if (bucket == 7*BUCKETS_PER_POW2) { /* Special case, explanation is above. */
2005            union overhead *n_op = nextf[7*BUCKETS_PER_POW2]->ov_next;
2006            nextf[7*BUCKETS_PER_POW2] = 
2007                (union overhead *)((caddr_t)nextf[7*BUCKETS_PER_POW2] 
2008                                   - sizeof(union overhead));
2009            nextf[7*BUCKETS_PER_POW2]->ov_next = n_op;
2010        }
2011#endif /* !PACK_MALLOC */
2012}
2013
2014Free_t
2015Perl_mfree(Malloc_t where)
2016{
2017        dVAR;
2018        register MEM_SIZE size;
2019        register union overhead *ovp;
2020        char *cp = (char*)where;
2021#ifdef PACK_MALLOC
2022        u_char bucket;
2023#endif 
2024
2025        DEBUG_m(PerlIO_printf(Perl_debug_log, 
2026                              "0x%"UVxf": (%05lu) free\n",
2027                              PTR2UV(cp), (unsigned long)(PL_an++)));
2028
2029        if (cp == NULL)
2030                return;
2031#ifdef DEBUGGING
2032        if (PTR2UV(cp) & (MEM_ALIGNBYTES - 1))
2033            croak("%s", "wrong alignment in free()");
2034#endif
2035        ovp = (union overhead *)((caddr_t)cp 
2036                                - sizeof (union overhead) * CHUNK_SHIFT);
2037#ifdef PACK_MALLOC
2038        bucket = OV_INDEX(ovp);
2039#endif 
2040#ifdef IGNORE_SMALL_BAD_FREE
2041        if ((bucket >= FIRST_BUCKET_WITH_CHECK) 
2042            && (OV_MAGIC(ovp, bucket) != MAGIC))
2043#else
2044        if (OV_MAGIC(ovp, bucket) != MAGIC)
2045#endif 
2046            {
2047                static int bad_free_warn = -1;
2048                if (bad_free_warn == -1) {
2049                    dTHX;
2050                    char *pbf = PerlEnv_getenv("PERL_BADFREE");
2051                    bad_free_warn = (pbf) ? atoi(pbf) : 1;
2052                }
2053                if (!bad_free_warn)
2054                    return;
2055#ifdef RCHECK
2056#ifdef PERL_CORE
2057                {
2058                    dTHX;
2059                    if (!PERL_IS_ALIVE || !PL_curcop || ckWARN_d(WARN_MALLOC))
2060                        Perl_warner(aTHX_ packWARN(WARN_MALLOC), "%s free() ignored (RMAGIC, PERL_CORE)",
2061                                    ovp->ov_rmagic == RMAGIC - 1 ?
2062                                    "Duplicate" : "Bad");
2063                }
2064#else
2065                warn("%s free() ignored (RMAGIC)",
2066                    ovp->ov_rmagic == RMAGIC - 1 ? "Duplicate" : "Bad");
2067#endif          
2068#else
2069#ifdef PERL_CORE
2070                {
2071                    dTHX;
2072                    if (!PERL_IS_ALIVE || !PL_curcop || ckWARN_d(WARN_MALLOC))
2073                        Perl_warner(aTHX_ packWARN(WARN_MALLOC), "%s", "Bad free() ignored (PERL_CORE)");
2074                }
2075#else
2076                warn("%s", "Bad free() ignored");
2077#endif
2078#endif
2079                return;                         /* sanity */
2080            }
2081#ifdef RCHECK
2082        ASSERT(ovp->ov_rmagic == RMAGIC, "chunk's head overwrite");
2083        if (OV_INDEX(ovp) <= MAX_SHORT_BUCKET) {
2084            int i;
2085            MEM_SIZE nbytes = ovp->ov_size + 1;
2086
2087            if ((i = nbytes & (RMAGIC_SZ-1))) {
2088                i = RMAGIC_SZ - i;
2089                while (i--) {   /* nbytes - RMAGIC_SZ is end of alloced area */
2090                    ASSERT(((caddr_t)ovp + nbytes - RMAGIC_SZ)[i] == RMAGIC_C,
2091                           "chunk's tail overwrite");
2092                }
2093            }
2094            /* Same at RMAGIC_SZ-aligned RMAGIC */
2095            nbytes = (nbytes + (RMAGIC_SZ-1)) & ~(RMAGIC_SZ-1);
2096            ASSERT(((u_int *)((caddr_t)ovp + nbytes))[-1] == RMAGIC,
2097                   "chunk's tail overwrite");       
2098            FILLCHECK_DEADBEEF((unsigned char*)((caddr_t)ovp + nbytes),
2099                               BUCKET_SIZE(OV_INDEX(ovp)) - nbytes);
2100        }
2101        FILL_DEADBEEF((unsigned char*)(ovp+CHUNK_SHIFT),
2102                      BUCKET_SIZE_REAL(OV_INDEX(ovp)) + RMAGIC_SZ);
2103        ovp->ov_rmagic = RMAGIC - 1;
2104#endif
2105        ASSERT(OV_INDEX(ovp) < NBUCKETS, "chunk's head overwrite");
2106        size = OV_INDEX(ovp);
2107
2108        MALLOC_LOCK;
2109        ovp->ov_next = nextf[size];
2110        nextf[size] = ovp;
2111        MALLOC_UNLOCK;
2112}
2113
2114/* There is no need to do any locking in realloc (with an exception of
2115   trying to grow in place if we are at the end of the chain).
2116   If somebody calls us from a different thread with the same address,
2117   we are sole anyway.  */
2118
2119Malloc_t
2120Perl_realloc(void *mp, size_t nbytes)
2121{
2122        dVAR;
2123        register MEM_SIZE onb;
2124        union overhead *ovp;
2125        char *res;
2126        int prev_bucket;
2127        register int bucket;
2128        int incr;               /* 1 if does not fit, -1 if "easily" fits in a
2129                                   smaller bucket, otherwise 0.  */
2130        char *cp = (char*)mp;
2131
2132#if defined(DEBUGGING) || !defined(PERL_CORE)
2133        MEM_SIZE size = nbytes;
2134
2135        if ((long)nbytes < 0)
2136            croak("%s", "panic: realloc");
2137#endif
2138
2139        BARK_64K_LIMIT("Reallocation",nbytes,size);
2140        if (!cp)
2141                return Perl_malloc(nbytes);
2142
2143        ovp = (union overhead *)((caddr_t)cp 
2144                                - sizeof (union overhead) * CHUNK_SHIFT);
2145        bucket = OV_INDEX(ovp);
2146
2147#ifdef IGNORE_SMALL_BAD_FREE
2148        if ((bucket >= FIRST_BUCKET_WITH_CHECK) 
2149            && (OV_MAGIC(ovp, bucket) != MAGIC))
2150#else
2151        if (OV_MAGIC(ovp, bucket) != MAGIC)
2152#endif 
2153            {
2154                static int bad_free_warn = -1;
2155                if (bad_free_warn == -1) {
2156                    dTHX;
2157                    char *pbf = PerlEnv_getenv("PERL_BADFREE");
2158                    bad_free_warn = (pbf) ? atoi(pbf) : 1;
2159                }
2160                if (!bad_free_warn)
2161                    return NULL;
2162#ifdef RCHECK
2163#ifdef PERL_CORE
2164                {
2165                    dTHX;
2166                    if (!PERL_IS_ALIVE || !PL_curcop || ckWARN_d(WARN_MALLOC))
2167                        Perl_warner(aTHX_ packWARN(WARN_MALLOC), "%srealloc() %signored",
2168                                    (ovp->ov_rmagic == RMAGIC - 1 ? "" : "Bad "),
2169                                    ovp->ov_rmagic == RMAGIC - 1
2170                                    ? "of freed memory " : "");
2171                }
2172#else
2173                warn2("%srealloc() %signored",
2174                      (ovp->ov_rmagic == RMAGIC - 1 ? "" : "Bad "),
2175                      ovp->ov_rmagic == RMAGIC - 1 ? "of freed memory " : "");
2176#endif
2177#else
2178#ifdef PERL_CORE
2179                {
2180                    dTHX;
2181                    if (!PERL_IS_ALIVE || !PL_curcop || ckWARN_d(WARN_MALLOC))
2182                        Perl_warner(aTHX_ packWARN(WARN_MALLOC), "%s",
2183                                    "Bad realloc() ignored");
2184                }
2185#else
2186                warn("%s", "Bad realloc() ignored");
2187#endif
2188#endif
2189                return NULL;                    /* sanity */
2190            }
2191
2192        onb = BUCKET_SIZE_REAL(bucket);
2193        /* 
2194         *  avoid the copy if same size block.
2195         *  We are not agressive with boundary cases. Note that it might
2196         *  (for a small number of cases) give false negative if
2197         *  both new size and old one are in the bucket for
2198         *  FIRST_BIG_POW2, but the new one is near the lower end.
2199         *
2200         *  We do not try to go to 1.5 times smaller bucket so far.
2201         */
2202        if (nbytes > onb) incr = 1;
2203        else {
2204#ifdef DO_NOT_TRY_HARDER_WHEN_SHRINKING
2205            if ( /* This is a little bit pessimal if PACK_MALLOC: */
2206                nbytes > ( (onb >> 1) - M_OVERHEAD )
2207#  ifdef TWO_POT_OPTIMIZE
2208                || (bucket == FIRST_BIG_POW2 && nbytes >= LAST_SMALL_BOUND )
2209#  endif        
2210                )
2211#else  /* !DO_NOT_TRY_HARDER_WHEN_SHRINKING */
2212                prev_bucket = ( (bucket > MAX_PACKED + 1) 
2213                                ? bucket - BUCKETS_PER_POW2
2214                                : bucket - 1);
2215             if (nbytes > BUCKET_SIZE_REAL(prev_bucket))
2216#endif /* !DO_NOT_TRY_HARDER_WHEN_SHRINKING */
2217                 incr = 0;
2218             else incr = -1;
2219        }
2220#ifdef STRESS_REALLOC
2221        goto hard_way;
2222#endif
2223        if (incr == 0) {
2224          inplace_label:
2225#ifdef RCHECK
2226                /*
2227                 * Record new allocated size of block and
2228                 * bound space with magic numbers.
2229                 */
2230                if (OV_INDEX(ovp) <= MAX_SHORT_BUCKET) {
2231                       int i, nb = ovp->ov_size + 1;
2232
2233                       if ((i = nb & (RMAGIC_SZ-1))) {
2234                           i = RMAGIC_SZ - i;
2235                           while (i--) { /* nb - RMAGIC_SZ is end of alloced area */
2236                               ASSERT(((caddr_t)ovp + nb - RMAGIC_SZ)[i] == RMAGIC_C, "chunk's tail overwrite");
2237                           }
2238                       }
2239                       /* Same at RMAGIC_SZ-aligned RMAGIC */
2240                       nb = (nb + (RMAGIC_SZ-1)) & ~(RMAGIC_SZ-1);
2241                       ASSERT(((u_int *)((caddr_t)ovp + nb))[-1] == RMAGIC,
2242                              "chunk's tail overwrite");
2243                       FILLCHECK_DEADBEEF((unsigned char*)((caddr_t)ovp + nb),
2244                                          BUCKET_SIZE(OV_INDEX(ovp)) - nb);
2245                       if (nbytes > ovp->ov_size + 1 - M_OVERHEAD)
2246                           FILL_FEEDADAD((unsigned char*)cp + ovp->ov_size + 1 - M_OVERHEAD,
2247                                     nbytes - (ovp->ov_size + 1 - M_OVERHEAD));
2248                       else
2249                           FILL_DEADBEEF((unsigned char*)cp + nbytes,
2250                                         nb - M_OVERHEAD + RMAGIC_SZ - nbytes);
2251                        /*
2252                         * Convert amount of memory requested into
2253                         * closest block size stored in hash buckets
2254                         * which satisfies request.  Account for
2255                         * space used per block for accounting.
2256                         */
2257                        nbytes += M_OVERHEAD;
2258                        ovp->ov_size = nbytes - 1;
2259                        if ((i = nbytes & (RMAGIC_SZ-1))) {
2260                            i = RMAGIC_SZ - i;
2261                            while (i--) /* nbytes - RMAGIC_SZ is end of alloced area */
2262                                ((caddr_t)ovp + nbytes - RMAGIC_SZ)[i]
2263                                    = RMAGIC_C;
2264                        }
2265                        /* Same at RMAGIC_SZ-aligned RMAGIC */
2266                        nbytes = (nbytes + (RMAGIC_SZ-1)) & ~(RMAGIC_SZ - 1);
2267                        ((u_int *)((caddr_t)ovp + nbytes))[-1] = RMAGIC;
2268                }
2269#endif
2270                res = cp;
2271                DEBUG_m(PerlIO_printf(Perl_debug_log, 
2272                              "0x%"UVxf": (%05lu) realloc %ld bytes inplace\n",
2273                              PTR2UV(res),(unsigned long)(PL_an++),
2274                              (long)size));
2275        } else if (incr == 1 && (cp - M_OVERHEAD == last_op) 
2276                   && (onb > (1 << LOG_OF_MIN_ARENA))) {
2277            MEM_SIZE require, newarena = nbytes, pow;
2278            int shiftr;
2279
2280            POW2_OPTIMIZE_ADJUST(newarena);
2281            newarena = newarena + M_OVERHEAD;
2282            /* newarena = (newarena + 3) &~ 3; */
2283            shiftr = (newarena - 1) >> LOG_OF_MIN_ARENA;
2284            pow = LOG_OF_MIN_ARENA + 1;
2285            /* apart from this loop, this is O(1) */
2286            while (shiftr >>= 1)
2287                pow++;
2288            newarena = (1 << pow) + POW2_OPTIMIZE_SURPLUS(pow * BUCKETS_PER_POW2);
2289            require = newarena - onb - M_OVERHEAD;
2290            
2291            MALLOC_LOCK;
2292            if (cp - M_OVERHEAD == last_op /* We *still* are the last chunk */
2293                && getpages_adjacent(require)) {
2294#ifdef DEBUGGING_MSTATS
2295                nmalloc[bucket]--;
2296                nmalloc[pow * BUCKETS_PER_POW2]++;
2297#endif      
2298                if (pow * BUCKETS_PER_POW2 > (MEM_SIZE)max_bucket)
2299                    max_bucket = pow * BUCKETS_PER_POW2;
2300                *(cp - M_OVERHEAD) = pow * BUCKETS_PER_POW2; /* Fill index. */
2301                MALLOC_UNLOCK;
2302                goto inplace_label;
2303            } else {
2304                MALLOC_UNLOCK;          
2305                goto hard_way;
2306            }
2307        } else {
2308          hard_way:
2309            DEBUG_m(PerlIO_printf(Perl_debug_log, 
2310                              "0x%"UVxf": (%05lu) realloc %ld bytes the hard way\n",
2311                              PTR2UV(cp),(unsigned long)(PL_an++),
2312                              (long)size));
2313            if ((res = (char*)Perl_malloc(nbytes)) == NULL)
2314                return (NULL);
2315            if (cp != res)                      /* common optimization */
2316                Copy(cp, res, (MEM_SIZE)(nbytes<onb?nbytes:onb), char);
2317            Perl_mfree(cp);
2318        }
2319        return ((Malloc_t)res);
2320}
2321
2322Malloc_t
2323Perl_calloc(register size_t elements, register size_t size)
2324{
2325    long sz = elements * size;
2326    Malloc_t p = Perl_malloc(sz);
2327
2328    if (p) {
2329        memset((void*)p, 0, sz);
2330    }
2331    return p;
2332}
2333
2334char *
2335Perl_strdup(const char *s)
2336{
2337    MEM_SIZE l = strlen(s);
2338    char *s1 = (char *)Perl_malloc(l+1);
2339
2340    return (char *)CopyD(s, s1, (MEM_SIZE)(l+1), char);
2341}
2342
2343#ifdef PERL_CORE
2344int
2345Perl_putenv(char *a)
2346{
2347    /* Sometimes system's putenv conflicts with my_setenv() - this is system
2348       malloc vs Perl's free(). */
2349  dTHX;
2350  char *var;
2351  char *val = a;
2352  MEM_SIZE l;
2353  char buf[80];
2354
2355  while (*val && *val != '=')
2356      val++;
2357  if (!*val)
2358      return -1;
2359  l = val - a;
2360  if (l < sizeof(buf))
2361      var = buf;
2362  else
2363      var = (char *)Perl_malloc(l + 1);
2364  Copy(a, var, l, char);
2365  var[l + 1] = 0;
2366  my_setenv(var, val+1);
2367  if (var != buf)
2368      Perl_mfree(var);
2369  return 0;
2370}
2371#  endif
2372
2373MEM_SIZE
2374Perl_malloced_size(void *p)
2375{
2376    union overhead * const ovp = (union overhead *)
2377        ((caddr_t)p - sizeof (union overhead) * CHUNK_SHIFT);
2378    const int bucket = OV_INDEX(ovp);
2379
2380    PERL_ARGS_ASSERT_MALLOCED_SIZE;
2381
2382#ifdef RCHECK
2383    /* The caller wants to have a complete control over the chunk,
2384       disable the memory checking inside the chunk.  */
2385    if (bucket <= MAX_SHORT_BUCKET) {
2386        const MEM_SIZE size = BUCKET_SIZE_REAL(bucket);
2387        ovp->ov_size = size + M_OVERHEAD - 1;
2388        *((u_int *)((caddr_t)ovp + size + M_OVERHEAD - RMAGIC_SZ)) = RMAGIC;
2389    }
2390#endif
2391    return BUCKET_SIZE_REAL(bucket);
2392}
2393
2394
2395MEM_SIZE
2396Perl_malloc_good_size(size_t wanted)
2397{
2398    return BUCKET_SIZE_REAL(S_ajust_size_and_find_bucket(&wanted));
2399}
2400
2401#  ifdef BUCKETS_ROOT2
2402#    define MIN_EVEN_REPORT 6
2403#  else
2404#    define MIN_EVEN_REPORT MIN_BUCKET
2405#  endif 
2406
2407int
2408Perl_get_mstats(pTHX_ perl_mstats_t *buf, int buflen, int level)
2409{
2410#ifdef DEBUGGING_MSTATS
2411        register int i, j;
2412        register union overhead *p;
2413        struct chunk_chain_s* nextchain;
2414
2415        PERL_ARGS_ASSERT_GET_MSTATS;
2416
2417        buf->topbucket = buf->topbucket_ev = buf->topbucket_odd 
2418            = buf->totfree = buf->total = buf->total_chain = 0;
2419
2420        buf->minbucket = MIN_BUCKET;
2421        MALLOC_LOCK;
2422        for (i = MIN_BUCKET ; i < NBUCKETS; i++) {
2423                for (j = 0, p = nextf[i]; p; p = p->ov_next, j++)
2424                        ;
2425                if (i < buflen) {
2426                    buf->nfree[i] = j;
2427                    buf->ntotal[i] = nmalloc[i];
2428                }               
2429                buf->totfree += j * BUCKET_SIZE_REAL(i);
2430                buf->total += nmalloc[i] * BUCKET_SIZE_REAL(i);
2431                if (nmalloc[i]) {
2432                    i % 2 ? (buf->topbucket_odd = i) : (buf->topbucket_ev = i);
2433                    buf->topbucket = i;
2434                }
2435        }
2436        nextchain = chunk_chain;
2437        while (nextchain) {
2438            buf->total_chain += nextchain->size;
2439            nextchain = nextchain->next;
2440        }
2441        buf->total_sbrk = goodsbrk + sbrk_slack;
2442        buf->sbrks = sbrks;
2443        buf->sbrk_good = sbrk_goodness;
2444        buf->sbrk_slack = sbrk_slack;
2445        buf->start_slack = start_slack;
2446        buf->sbrked_remains = sbrked_remains;
2447        MALLOC_UNLOCK;
2448        buf->nbuckets = NBUCKETS;
2449        if (level) {
2450            for (i = MIN_BUCKET ; i < NBUCKETS; i++) {
2451                if (i >= buflen)
2452                    break;
2453                buf->bucket_mem_size[i] = BUCKET_SIZE_NO_SURPLUS(i);
2454                buf->bucket_available_size[i] = BUCKET_SIZE_REAL(i);
2455            }
2456        }
2457#else /* defined DEBUGGING_MSTATS */
2458        PerlIO_printf(Perl_error_log, "perl not compiled with DEBUGGING_MSTATS\n");
2459#endif  /* defined DEBUGGING_MSTATS */
2460        return 0;               /* XXX unused */
2461}
2462/*
2463 * mstats - print out statistics about malloc
2464 * 
2465 * Prints two lines of numbers, one showing the length of the free list
2466 * for each size category, the second showing the number of mallocs -
2467 * frees for each size category.
2468 */
2469void
2470Perl_dump_mstats(pTHX_ char *s)
2471{
2472#ifdef DEBUGGING_MSTATS
2473        register int i;
2474        perl_mstats_t buffer;
2475        UV nf[NBUCKETS];
2476        UV nt[NBUCKETS];
2477
2478        PERL_ARGS_ASSERT_DUMP_MSTATS;
2479
2480        buffer.nfree  = nf;
2481        buffer.ntotal = nt;
2482        get_mstats(&buffer, NBUCKETS, 0);
2483
2484        if (s)
2485            PerlIO_printf(Perl_error_log,
2486                          "Memory allocation statistics %s (buckets %"IVdf"(%"IVdf")..%"IVdf"(%"IVdf")\n",
2487                          s, 
2488                          (IV)BUCKET_SIZE_REAL(MIN_BUCKET), 
2489                          (IV)BUCKET_SIZE_NO_SURPLUS(MIN_BUCKET),
2490                          (IV)BUCKET_SIZE_REAL(buffer.topbucket), 
2491                          (IV)BUCKET_SIZE_NO_SURPLUS(buffer.topbucket));
2492        PerlIO_printf(Perl_error_log, "%8"IVdf" free:", buffer.totfree);
2493        for (i = MIN_EVEN_REPORT; i <= buffer.topbucket; i += BUCKETS_PER_POW2) {
2494                PerlIO_printf(Perl_error_log, 
2495                              ((i < 8*BUCKETS_PER_POW2 || i == 10*BUCKETS_PER_POW2)
2496                               ? " %5"UVuf 
2497                               : ((i < 12*BUCKETS_PER_POW2) ? " %3"UVuf : " %"UVuf)),
2498                              buffer.nfree[i]);
2499        }
2500#ifdef BUCKETS_ROOT2
2501        PerlIO_printf(Perl_error_log, "\n\t   ");
2502        for (i = MIN_BUCKET + 1; i <= buffer.topbucket_odd; i += BUCKETS_PER_POW2) {
2503                PerlIO_printf(Perl_error_log, 
2504                              ((i < 8*BUCKETS_PER_POW2 || i == 10*BUCKETS_PER_POW2)
2505                               ? " %5"UVuf 
2506                               : ((i < 12*BUCKETS_PER_POW2) ? " %3"UVuf : " %"UVuf)),
2507                              buffer.nfree[i]);
2508        }
2509#endif 
2510        PerlIO_printf(Perl_error_log, "\n%8"IVdf" used:", buffer.total - buffer.totfree);
2511        for (i = MIN_EVEN_REPORT; i <= buffer.topbucket; i += BUCKETS_PER_POW2) {
2512                PerlIO_printf(Perl_error_log, 
2513                              ((i < 8*BUCKETS_PER_POW2 || i == 10*BUCKETS_PER_POW2)
2514                               ? " %5"IVdf
2515                               : ((i < 12*BUCKETS_PER_POW2) ? " %3"IVdf : " %"IVdf)), 
2516                              buffer.ntotal[i] - buffer.nfree[i]);
2517        }
2518#ifdef BUCKETS_ROOT2
2519        PerlIO_printf(Perl_error_log, "\n\t   ");
2520        for (i = MIN_BUCKET + 1; i <= buffer.topbucket_odd; i += BUCKETS_PER_POW2) {
2521                PerlIO_printf(Perl_error_log, 
2522                              ((i < 8*BUCKETS_PER_POW2 || i == 10*BUCKETS_PER_POW2)
2523                               ? " %5"IVdf 
2524                               : ((i < 12*BUCKETS_PER_POW2) ? " %3"IVdf : " %"IVdf)),
2525                              buffer.ntotal[i] - buffer.nfree[i]);
2526        }
2527#endif 
2528        PerlIO_printf(Perl_error_log, "\nTotal sbrk(): %"IVdf"/%"IVdf":%"IVdf". Odd ends: pad+heads+chain+tail: %"IVdf"+%"IVdf"+%"IVdf"+%"IVdf".\n",
2529                      buffer.total_sbrk, buffer.sbrks, buffer.sbrk_good,
2530                      buffer.sbrk_slack, buffer.start_slack,
2531                      buffer.total_chain, buffer.sbrked_remains);
2532#else /* DEBUGGING_MSTATS */
2533        PerlIO_printf(Perl_error_log, "%s: perl not compiled with DEBUGGING_MSTATS\n",s);
2534#endif /* DEBUGGING_MSTATS */
2535}
2536
2537#ifdef USE_PERL_SBRK
2538
2539#   if defined(__MACHTEN_PPC__) || defined(NeXT) || defined(__NeXT__) || defined(PURIFY)
2540#      define PERL_SBRK_VIA_MALLOC
2541#   endif
2542
2543#   ifdef PERL_SBRK_VIA_MALLOC
2544
2545/* it may seem schizophrenic to use perl's malloc and let it call system */
2546/* malloc, the reason for that is only the 3.2 version of the OS that had */
2547/* frequent core dumps within nxzonefreenolock. This sbrk routine put an */
2548/* end to the cores */
2549
2550#      ifndef SYSTEM_ALLOC
2551#         define SYSTEM_ALLOC(a) malloc(a)
2552#      endif
2553#      ifndef SYSTEM_ALLOC_ALIGNMENT
2554#         define SYSTEM_ALLOC_ALIGNMENT MEM_ALIGNBYTES
2555#      endif
2556
2557#   endif  /* PERL_SBRK_VIA_MALLOC */
2558
2559static IV Perl_sbrk_oldchunk;
2560static long Perl_sbrk_oldsize;
2561
2562#   define PERLSBRK_32_K (1<<15)
2563#   define PERLSBRK_64_K (1<<16)
2564
2565Malloc_t
2566Perl_sbrk(int size)
2567{
2568    IV got;
2569    int small, reqsize;
2570
2571    if (!size) return 0;
2572#ifdef PERL_CORE
2573    reqsize = size; /* just for the DEBUG_m statement */
2574#endif
2575#ifdef PACK_MALLOC
2576    size = (size + 0x7ff) & ~0x7ff;
2577#endif
2578    if (size <= Perl_sbrk_oldsize) {
2579        got = Perl_sbrk_oldchunk;
2580        Perl_sbrk_oldchunk += size;
2581        Perl_sbrk_oldsize -= size;
2582    } else {
2583      if (size >= PERLSBRK_32_K) {
2584        small = 0;
2585      } else {
2586        size = PERLSBRK_64_K;
2587        small = 1;
2588      }
2589#  if NEEDED_ALIGNMENT > SYSTEM_ALLOC_ALIGNMENT
2590      size += NEEDED_ALIGNMENT - SYSTEM_ALLOC_ALIGNMENT;
2591#  endif
2592      got = (IV)SYSTEM_ALLOC(size);
2593#  if NEEDED_ALIGNMENT > SYSTEM_ALLOC_ALIGNMENT
2594      got = (got + NEEDED_ALIGNMENT - 1) & ~(NEEDED_ALIGNMENT - 1);
2595#  endif
2596      if (small) {
2597        /* Chunk is small, register the rest for future allocs. */
2598        Perl_sbrk_oldchunk = got + reqsize;
2599        Perl_sbrk_oldsize = size - reqsize;
2600      }
2601    }
2602
2603    DEBUG_m(PerlIO_printf(Perl_debug_log, "sbrk malloc size %ld (reqsize %ld), left size %ld, give addr 0x%"UVxf"\n",
2604                    size, reqsize, Perl_sbrk_oldsize, PTR2UV(got)));
2605
2606    return (void *)got;
2607}
2608
2609#endif /* ! defined USE_PERL_SBRK */
2610
2611/*
2612 * Local variables:
2613 * c-indentation-style: bsd
2614 * c-basic-offset: 4
2615 * indent-tabs-mode: t
2616 * End:
2617 *
2618 * ex: set ts=8 sts=4 sw=4 noet:
2619 */
2620
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