*
*/
-#if defined(PERL_CORE) && !defined(DEBUGGING_MSTATS)
-# define DEBUGGING_MSTATS
+/*
+ Here are some notes on configuring Perl's malloc. (For non-perl
+ usage see below.)
+
+ There are two macros which serve as bulk disablers of advanced
+ features of this malloc: NO_FANCY_MALLOC, PLAIN_MALLOC (undef by
+ default). Look in the list of default values below to understand
+ their exact effect. Defining NO_FANCY_MALLOC returns malloc.c to the
+ state of the malloc in Perl 5.004. Additionally defining PLAIN_MALLOC
+ returns it to the state as of Perl 5.000.
+
+ Note that some of the settings below may be ignored in the code based
+ on values of other macros. The PERL_CORE symbol is only defined when
+ perl itself is being compiled (so malloc can make some assumptions
+ about perl's facilities being available to it).
+
+ Each config option has a short description, followed by its name,
+ default value, and a comment about the default (if applicable). Some
+ options take a precise value, while the others are just boolean.
+ The boolean ones are listed first.
+
+ # Enable code for an emergency memory pool in $^M. See perlvar.pod
+ # for a description of $^M.
+ PERL_EMERGENCY_SBRK (!PLAIN_MALLOC && PERL_CORE)
+
+ # Enable code for printing memory statistics.
+ DEBUGGING_MSTATS (!PLAIN_MALLOC && PERL_CORE)
+
+ # Move allocation info for small buckets into separate areas.
+ # Memory optimization (especially for small allocations, of the
+ # less than 64 bytes). Since perl usually makes a large number
+ # of small allocations, this is usually a win.
+ PACK_MALLOC (!PLAIN_MALLOC && !RCHECK)
+
+ # Add one page to big powers of two when calculating bucket size.
+ # This is targeted at big allocations, as are common in image
+ # processing.
+ TWO_POT_OPTIMIZE !PLAIN_MALLOC
+
+ # Use intermediate bucket sizes between powers-of-two. This is
+ # generally a memory optimization, and a (small) speed pessimization.
+ BUCKETS_ROOT2 !NO_FANCY_MALLOC
+
+ # Do not check small deallocations for bad free(). Memory
+ # and speed optimization, error reporting pessimization.
+ IGNORE_SMALL_BAD_FREE (!NO_FANCY_MALLOC && !RCHECK)
+
+ # Use table lookup to decide in which bucket a given allocation will go.
+ SMALL_BUCKET_VIA_TABLE !NO_FANCY_MALLOC
+
+ # Use a perl-defined sbrk() instead of the (presumably broken or
+ # missing) system-supplied sbrk().
+ USE_PERL_SBRK undef
+
+ # Use system malloc() (or calloc() etc.) to emulate sbrk(). Normally
+ # only used with broken sbrk()s.
+ PERL_SBRK_VIA_MALLOC undef
+
+ # Which allocator to use if PERL_SBRK_VIA_MALLOC
+ SYSTEM_ALLOC(a) malloc(a)
+
+ # Minimal alignment (in bytes, should be a power of 2) of SYSTEM_ALLOC
+ SYSTEM_ALLOC_ALIGNMENT MEM_ALIGNBYTES
+
+ # Disable memory overwrite checking with DEBUGGING. Memory and speed
+ # optimization, error reporting pessimization.
+ NO_RCHECK undef
+
+ # Enable memory overwrite checking with DEBUGGING. Memory and speed
+ # pessimization, error reporting optimization
+ RCHECK (DEBUGGING && !NO_RCHECK)
+
+ # Failed allocations bigger than this size croak (if
+ # PERL_EMERGENCY_SBRK is enabled) without touching $^M. See
+ # perlvar.pod for a description of $^M.
+ BIG_SIZE (1<<16) # 64K
+
+ # Starting from this power of two, add an extra page to the
+ # size of the bucket. This enables optimized allocations of sizes
+ # close to powers of 2. Note that the value is indexed at 0.
+ FIRST_BIG_POW2 15 # 32K, 16K is used too often
+
+ # Estimate of minimal memory footprint. malloc uses this value to
+ # request the most reasonable largest blocks of memory from the system.
+ FIRST_SBRK (48*1024)
+
+ # Round up sbrk()s to multiples of this.
+ MIN_SBRK 2048
+
+ # Round up sbrk()s to multiples of this percent of footprint.
+ MIN_SBRK_FRAC 3
+
+ # Add this much memory to big powers of two to get the bucket size.
+ PERL_PAGESIZE 4096
+
+ # This many sbrk() discontinuities should be tolerated even
+ # from the start without deciding that sbrk() is usually
+ # discontinuous.
+ SBRK_ALLOW_FAILURES 3
+
+ # This many continuous sbrk()s compensate for one discontinuous one.
+ SBRK_FAILURE_PRICE 50
+
+ # Some configurations may ask for 12-byte-or-so allocations which
+ # require 8-byte alignment (?!). In such situation one needs to
+ # define this to disable 12-byte bucket (will increase memory footprint)
+ STRICT_ALIGNMENT undef
+
+ This implementation assumes that calling PerlIO_printf() does not
+ result in any memory allocation calls (used during a panic).
+
+ */
+
+/*
+ If used outside of Perl environment, it may be useful to redefine
+ the following macros (listed below with defaults):
+
+ # Type of address returned by allocation functions
+ Malloc_t void *
+
+ # Type of size argument for allocation functions
+ MEM_SIZE unsigned long
+
+ # size of void*
+ PTRSIZE 4
+
+ # Maximal value in LONG
+ LONG_MAX 0x7FFFFFFF
+
+ # Unsigned integer type big enough to keep a pointer
+ UV unsigned long
+
+ # Type of pointer with 1-byte granularity
+ caddr_t char *
+
+ # Type returned by free()
+ Free_t void
+
+ # Very fatal condition reporting function (cannot call any )
+ fatalcroak(arg) write(2,arg,strlen(arg)) + exit(2)
+
+ # Fatal error reporting function
+ croak(format, arg) warn(idem) + exit(1)
+
+ # Error reporting function
+ warn(format, arg) fprintf(stderr, idem)
+
+ # Locking/unlocking for MT operation
+ MALLOC_LOCK MUTEX_LOCK(&PL_malloc_mutex)
+ MALLOC_UNLOCK MUTEX_UNLOCK(&PL_malloc_mutex)
+
+ # Locking/unlocking mutex for MT operation
+ MUTEX_LOCK(l) void
+ MUTEX_UNLOCK(l) void
+ */
+
+#ifndef NO_FANCY_MALLOC
+# ifndef SMALL_BUCKET_VIA_TABLE
+# define SMALL_BUCKET_VIA_TABLE
+# endif
+# ifndef BUCKETS_ROOT2
+# define BUCKETS_ROOT2
+# endif
+# ifndef IGNORE_SMALL_BAD_FREE
+# define IGNORE_SMALL_BAD_FREE
+# endif
#endif
+#ifndef PLAIN_MALLOC /* Bulk enable features */
+# ifndef PACK_MALLOC
+# define PACK_MALLOC
+# endif
+# ifndef TWO_POT_OPTIMIZE
+# define TWO_POT_OPTIMIZE
+# endif
+# if defined(PERL_CORE) && !defined(PERL_EMERGENCY_SBRK)
+# define PERL_EMERGENCY_SBRK
+# endif
+# if defined(PERL_CORE) && !defined(DEBUGGING_MSTATS)
+# define DEBUGGING_MSTATS
+# endif
+#endif
+
+#define MIN_BUC_POW2 (sizeof(void*) > 4 ? 3 : 2) /* Allow for 4-byte arena. */
+#define MIN_BUCKET (MIN_BUC_POW2 * BUCKETS_PER_POW2)
+
+#if !(defined(I286) || defined(atarist) || defined(__MINT__))
+ /* take 2k unless the block is bigger than that */
+# define LOG_OF_MIN_ARENA 11
+#else
+ /* take 16k unless the block is bigger than that
+ (80286s like large segments!), probably good on the atari too */
+# define LOG_OF_MIN_ARENA 14
+#endif
+
#ifndef lint
# if defined(DEBUGGING) && !defined(NO_RCHECK)
# define RCHECK
# endif
+# if defined(RCHECK) && defined(IGNORE_SMALL_BAD_FREE)
+# undef IGNORE_SMALL_BAD_FREE
+# endif
/*
* malloc.c (Caltech) 2/21/82
* Chris Kingsley, kingsley@cit-20.
* implementation, the available sizes are 2^n-4 (or 2^n-12) bytes long.
* If PACK_MALLOC is defined, small blocks are 2^n bytes long.
* This is designed for use in a program that uses vast quantities of memory,
- * but bombs when it runs out.
+ * but bombs when it runs out.
+ *
+ * Modifications Copyright Ilya Zakharevich 1996-99.
+ *
+ * Still very quick, but much more thrifty. (Std config is 10% slower
+ * than it was, and takes 67% of old heap size for typical usage.)
+ *
+ * Allocations of small blocks are now table-driven to many different
+ * buckets. Sizes of really big buckets are increased to accomodata
+ * common size=power-of-2 blocks. Running-out-of-memory is made into
+ * an exception. Deeply configurable and thread-safe.
+ *
*/
-#include "EXTERN.h"
-#include "perl.h"
+#ifdef PERL_CORE
+# include "EXTERN.h"
+# define PERL_IN_MALLOC_C
+# include "perl.h"
+# if defined(PERL_IMPLICIT_CONTEXT)
+# define croak Perl_croak_nocontext
+# define warn Perl_warn_nocontext
+# endif
+#else
+# ifdef PERL_FOR_X2P
+# include "../EXTERN.h"
+# include "../perl.h"
+# else
+# include <stdlib.h>
+# include <stdio.h>
+# include <memory.h>
+# define _(arg) arg
+# ifndef Malloc_t
+# define Malloc_t void *
+# endif
+# ifndef PTRSIZE
+# define PTRSIZE 4
+# endif
+# ifndef MEM_SIZE
+# define MEM_SIZE unsigned long
+# endif
+# ifndef LONG_MAX
+# define LONG_MAX 0x7FFFFFFF
+# endif
+# ifndef UV
+# define UV unsigned long
+# endif
+# ifndef caddr_t
+# define caddr_t char *
+# endif
+# ifndef Free_t
+# define Free_t void
+# endif
+# define Copy(s,d,n,t) (void)memcpy((char*)(d),(char*)(s), (n) * sizeof(t))
+# define PerlEnv_getenv getenv
+# define PerlIO_printf fprintf
+# define PerlIO_stderr() stderr
+# endif
+# ifndef croak /* make depend */
+# define croak(mess, arg) (warn((mess), (arg)), exit(1))
+# endif
+# ifndef warn
+# define warn(mess, arg) fprintf(stderr, (mess), (arg))
+# endif
+# ifdef DEBUG_m
+# undef DEBUG_m
+# endif
+# define DEBUG_m(a)
+# ifdef DEBUGGING
+# undef DEBUGGING
+# endif
+# ifndef pTHX
+# define pTHX void
+# define pTHX_
+# define dTHX extern int Perl___notused
+# define WITH_THX(s) s
+# endif
+# ifndef PERL_GET_INTERP
+# define PERL_GET_INTERP PL_curinterp
+# endif
+# ifndef Perl_malloc
+# define Perl_malloc malloc
+# endif
+# ifndef Perl_mfree
+# define Perl_mfree free
+# endif
+# ifndef Perl_realloc
+# define Perl_realloc realloc
+# endif
+# ifndef Perl_calloc
+# define Perl_calloc calloc
+# endif
+# ifndef Perl_strdup
+# define Perl_strdup strdup
+# endif
+#endif
+
+#ifndef MUTEX_LOCK
+# define MUTEX_LOCK(l)
+#endif
+
+#ifndef MUTEX_UNLOCK
+# define MUTEX_UNLOCK(l)
+#endif
+
+#ifndef MALLOC_LOCK
+# define MALLOC_LOCK MUTEX_LOCK(&PL_malloc_mutex)
+#endif
+
+#ifndef MALLOC_UNLOCK
+# define MALLOC_UNLOCK MUTEX_UNLOCK(&PL_malloc_mutex)
+#endif
+
+# ifndef fatalcroak /* make depend */
+# define fatalcroak(mess) (write(2, (mess), strlen(mess)), exit(2))
+# endif
#ifdef DEBUGGING
-#undef DEBUG_m
-#define DEBUG_m(a) if (debug & 128) a
+# undef DEBUG_m
+# define DEBUG_m(a) \
+ STMT_START { \
+ if (PERL_GET_INTERP) { dTHX; if (PL_debug & 128) { a; } } \
+ } STMT_END
#endif
+#ifdef PERL_IMPLICIT_CONTEXT
+# define PERL_IS_ALIVE aTHX
+#else
+# define PERL_IS_ALIVE TRUE
+#endif
+
+
+/*
+ * Layout of memory:
+ * ~~~~~~~~~~~~~~~~
+ * The memory is broken into "blocks" which occupy multiples of 2K (and
+ * generally speaking, have size "close" to a power of 2). The addresses
+ * of such *unused* blocks are kept in nextf[i] with big enough i. (nextf
+ * is an array of linked lists.) (Addresses of used blocks are not known.)
+ *
+ * Moreover, since the algorithm may try to "bite" smaller blocks out
+ * of unused bigger ones, there are also regions of "irregular" size,
+ * managed separately, by a linked list chunk_chain.
+ *
+ * The third type of storage is the sbrk()ed-but-not-yet-used space, its
+ * end and size are kept in last_sbrk_top and sbrked_remains.
+ *
+ * Growing blocks "in place":
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~
+ * The address of the block with the greatest address is kept in last_op
+ * (if not known, last_op is 0). If it is known that the memory above
+ * last_op is not continuous, or contains a chunk from chunk_chain,
+ * last_op is set to 0.
+ *
+ * The chunk with address last_op may be grown by expanding into
+ * sbrk()ed-but-not-yet-used space, or trying to sbrk() more continuous
+ * memory.
+ *
+ * Management of last_op:
+ * ~~~~~~~~~~~~~~~~~~~~~
+ *
+ * free() never changes the boundaries of blocks, so is not relevant.
+ *
+ * The only way realloc() may change the boundaries of blocks is if it
+ * grows a block "in place". However, in the case of success such a
+ * chunk is automatically last_op, and it remains last_op. In the case
+ * of failure getpages_adjacent() clears last_op.
+ *
+ * malloc() may change blocks by calling morecore() only.
+ *
+ * morecore() may create new blocks by:
+ * a) biting pieces from chunk_chain (cannot create one above last_op);
+ * b) biting a piece from an unused block (if block was last_op, this
+ * may create a chunk from chain above last_op, thus last_op is
+ * invalidated in such a case).
+ * c) biting of sbrk()ed-but-not-yet-used space. This creates
+ * a block which is last_op.
+ * d) Allocating new pages by calling getpages();
+ *
+ * getpages() creates a new block. It marks last_op at the bottom of
+ * the chunk of memory it returns.
+ *
+ * Active pages footprint:
+ * ~~~~~~~~~~~~~~~~~~~~~~
+ * Note that we do not need to traverse the lists in nextf[i], just take
+ * the first element of this list. However, we *need* to traverse the
+ * list in chunk_chain, but most the time it should be a very short one,
+ * so we do not step on a lot of pages we are not going to use.
+ *
+ * Flaws:
+ * ~~~~~
+ * get_from_bigger_buckets(): forget to increment price => Quite
+ * aggressive.
+ */
+
/* I don't much care whether these are defined in sys/types.h--LAW */
#define u_char unsigned char
#define u_int unsigned int
+/*
+ * I removed the definition of u_bigint which appeared to be u_bigint = UV
+ * u_bigint was only used in TWOK_MASKED and TWOK_SHIFT
+ * where I have used PTR2UV. RMB
+ */
#define u_short unsigned short
/* 286 and atarist like big chunks, which gives too much overhead. */
-#if (defined(RCHECK) || defined(I286) || defined(atarist)) && defined(PACK_MALLOC)
-#undef PACK_MALLOC
+#if (defined(RCHECK) || defined(I286) || defined(atarist) || defined(__MINT__)) && defined(PACK_MALLOC)
+# undef PACK_MALLOC
#endif
-
/*
* The description below is applicable if PACK_MALLOC is not defined.
*
double strut; /* alignment problems */
#endif
struct {
- u_char ovu_magic; /* magic number */
u_char ovu_index; /* bucket # */
+ u_char ovu_magic; /* magic number */
#ifdef RCHECK
u_short ovu_size; /* actual block size */
u_int ovu_rmagic; /* range magic number */
#define ov_rmagic ovu.ovu_rmagic
};
-#ifdef DEBUGGING
-static void botch _((char *s));
-#endif
-static void morecore _((int bucket));
-static int findbucket _((union overhead *freep, int srchlen));
-
#define MAGIC 0xff /* magic # on accounting info */
#define RMAGIC 0x55555555 /* magic # on range info */
+#define RMAGIC_C 0x55 /* magic # on range info */
+
#ifdef RCHECK
# define RSLOP sizeof (u_int)
# ifdef TWO_POT_OPTIMIZE
-# define MAX_SHORT_BUCKET 12
+# define MAX_SHORT_BUCKET (12 * BUCKETS_PER_POW2)
# else
-# define MAX_SHORT_BUCKET 13
+# define MAX_SHORT_BUCKET (13 * BUCKETS_PER_POW2)
# endif
#else
# define RSLOP 0
#endif
+#if !defined(PACK_MALLOC) && defined(BUCKETS_ROOT2)
+# undef BUCKETS_ROOT2
+#endif
+
+#ifdef BUCKETS_ROOT2
+# define BUCKET_TABLE_SHIFT 2
+# define BUCKET_POW2_SHIFT 1
+# define BUCKETS_PER_POW2 2
+#else
+# define BUCKET_TABLE_SHIFT MIN_BUC_POW2
+# define BUCKET_POW2_SHIFT 0
+# define BUCKETS_PER_POW2 1
+#endif
+
+#if !defined(MEM_ALIGNBYTES) || ((MEM_ALIGNBYTES > 4) && !defined(STRICT_ALIGNMENT))
+/* Figure out the alignment of void*. */
+struct aligner {
+ char c;
+ void *p;
+};
+# define ALIGN_SMALL ((int)((caddr_t)&(((struct aligner*)0)->p)))
+#else
+# define ALIGN_SMALL MEM_ALIGNBYTES
+#endif
+
+#define IF_ALIGN_8(yes,no) ((ALIGN_SMALL>4) ? (yes) : (no))
+
+#ifdef BUCKETS_ROOT2
+# define MAX_BUCKET_BY_TABLE 13
+static u_short buck_size[MAX_BUCKET_BY_TABLE + 1] =
+ {
+ 0, 0, 0, 0, 4, 4, 8, 12, 16, 24, 32, 48, 64, 80,
+ };
+# define BUCKET_SIZE(i) ((i) % 2 ? buck_size[i] : (1 << ((i) >> BUCKET_POW2_SHIFT)))
+# define BUCKET_SIZE_REAL(i) ((i) <= MAX_BUCKET_BY_TABLE \
+ ? buck_size[i] \
+ : ((1 << ((i) >> BUCKET_POW2_SHIFT)) \
+ - MEM_OVERHEAD(i) \
+ + POW2_OPTIMIZE_SURPLUS(i)))
+#else
+# define BUCKET_SIZE(i) (1 << ((i) >> BUCKET_POW2_SHIFT))
+# define BUCKET_SIZE_REAL(i) (BUCKET_SIZE(i) - MEM_OVERHEAD(i) + POW2_OPTIMIZE_SURPLUS(i))
+#endif
+
+
#ifdef PACK_MALLOC
-/*
- * In this case it is assumed that if we do sbrk() in 2K units, we
- * will get 2K aligned blocks. The bucket number of the given subblock is
- * on the boundary of 2K block which contains the subblock.
- * Several following bytes contain the magic numbers for the subblocks
- * in the block.
+/* In this case there are several possible layout of arenas depending
+ * on the size. Arenas are of sizes multiple to 2K, 2K-aligned, and
+ * have a size close to a power of 2.
*
- * Sizes of chunks are powers of 2 for chunks in buckets <=
- * MAX_PACKED, after this they are (2^n - sizeof(union overhead)) (to
- * get alignment right).
+ * Arenas of the size >= 4K keep one chunk only. Arenas of size 2K
+ * may keep one chunk or multiple chunks. Here are the possible
+ * layouts of arenas:
*
- * We suppose that starts of all the chunks in a 2K block are in
- * different 2^n-byte-long chunks. If the top of the last chunk is
- * aligned on a boundary of 2K block, this means that
- * sizeof(union overhead)*"number of chunks" < 2^n, or
- * sizeof(union overhead)*2K < 4^n, or n > 6 + log2(sizeof()/2)/2, if a
- * chunk of size 2^n - overhead is used. Since this rules out n = 7
- * for 8 byte alignment, we specialcase allocation of the first of 16
- * 128-byte-long chunks.
+ * # One chunk only, chunksize 2^k + SOMETHING - ALIGN, k >= 11
*
- * Note that with the above assumption we automatically have enough
- * place for MAGIC at the start of 2K block. Note also that we
- * overlay union overhead over the chunk, thus the start of the chunk
- * is immediately overwritten after freeing.
- */
-# define MAX_PACKED 6
-# define MAX_2_POT_ALGO ((1<<(MAX_PACKED + 1)) - M_OVERHEAD)
-# define TWOK_MASK ((1<<11) - 1)
-# define TWOK_MASKED(x) ((u_int)(x) & ~TWOK_MASK)
-# define TWOK_SHIFT(x) ((u_int)(x) & TWOK_MASK)
-# define OV_INDEXp(block) ((u_char*)(TWOK_MASKED(block)))
+ * INDEX MAGIC1 UNUSED CHUNK1
+ *
+ * # Multichunk with sanity checking and chunksize 2^k-ALIGN, k>7
+ *
+ * INDEX MAGIC1 MAGIC2 MAGIC3 UNUSED CHUNK1 CHUNK2 CHUNK3 ...
+ *
+ * # Multichunk with sanity checking and size 2^k-ALIGN, k=7
+ *
+ * INDEX MAGIC1 MAGIC2 MAGIC3 UNUSED CHUNK1 UNUSED CHUNK2 CHUNK3 ...
+ *
+ * # Multichunk with sanity checking and size up to 80
+ *
+ * INDEX UNUSED MAGIC1 UNUSED MAGIC2 UNUSED ... CHUNK1 CHUNK2 CHUNK3 ...
+ *
+ * # No sanity check (usually up to 48=byte-long buckets)
+ * INDEX UNUSED CHUNK1 CHUNK2 ...
+ *
+ * Above INDEX and MAGIC are one-byte-long. Sizes of UNUSED are
+ * appropriate to keep algorithms simple and memory aligned. INDEX
+ * encodes the size of the chunk, while MAGICn encodes state (used,
+ * free or non-managed-by-us-so-it-indicates-a-bug) of CHUNKn. MAGIC
+ * is used for sanity checking purposes only. SOMETHING is 0 or 4K
+ * (to make size of big CHUNK accomodate allocations for powers of two
+ * better).
+ *
+ * [There is no need to alignment between chunks, since C rules ensure
+ * that structs which need 2^k alignment have sizeof which is
+ * divisible by 2^k. Thus as far as the last chunk is aligned at the
+ * end of the arena, and 2K-alignment does not contradict things,
+ * everything is going to be OK for sizes of chunks 2^n and 2^n +
+ * 2^k. Say, 80-bit buckets will be 16-bit aligned, and as far as we
+ * put allocations for requests in 65..80 range, all is fine.
+ *
+ * Note, however, that standard malloc() puts more strict
+ * requirements than the above C rules. Moreover, our algorithms of
+ * realloc() may break this idyll, but we suppose that realloc() does
+ * need not change alignment.]
+ *
+ * Is very important to make calculation of the offset of MAGICm as
+ * quick as possible, since it is done on each malloc()/free(). In
+ * fact it is so quick that it has quite little effect on the speed of
+ * doing malloc()/free(). [By default] We forego such calculations
+ * for small chunks, but only to save extra 3% of memory, not because
+ * of speed considerations.
+ *
+ * Here is the algorithm [which is the same for all the allocations
+ * schemes above], see OV_MAGIC(block,bucket). Let OFFSETm be the
+ * offset of the CHUNKm from the start of ARENA. Then offset of
+ * MAGICm is (OFFSET1 >> SHIFT) + ADDOFFSET. Here SHIFT and ADDOFFSET
+ * are numbers which depend on the size of the chunks only.
+ *
+ * Let as check some sanity conditions. Numbers OFFSETm>>SHIFT are
+ * different for all the chunks in the arena if 2^SHIFT is not greater
+ * than size of the chunks in the arena. MAGIC1 will not overwrite
+ * INDEX provided ADDOFFSET is >0 if OFFSET1 < 2^SHIFT. MAGIClast
+ * will not overwrite CHUNK1 if OFFSET1 > (OFFSETlast >> SHIFT) +
+ * ADDOFFSET.
+ *
+ * Make SHIFT the maximal possible (there is no point in making it
+ * smaller). Since OFFSETlast is 2K - CHUNKSIZE, above restrictions
+ * give restrictions on OFFSET1 and on ADDOFFSET.
+ *
+ * In particular, for chunks of size 2^k with k>=6 we can put
+ * ADDOFFSET to be from 0 to 2^k - 2^(11-k), and have
+ * OFFSET1==chunksize. For chunks of size 80 OFFSET1 of 2K%80=48 is
+ * large enough to have ADDOFFSET between 1 and 16 (similarly for 96,
+ * when ADDOFFSET should be 1). In particular, keeping MAGICs for
+ * these sizes gives no additional size penalty.
+ *
+ * However, for chunks of size 2^k with k<=5 this gives OFFSET1 >=
+ * ADDOFSET + 2^(11-k). Keeping ADDOFFSET 0 allows for 2^(11-k)-2^(11-2k)
+ * chunks per arena. This is smaller than 2^(11-k) - 1 which are
+ * needed if no MAGIC is kept. [In fact, having a negative ADDOFFSET
+ * would allow for slightly more buckets per arena for k=2,3.]
+ *
+ * Similarly, for chunks of size 3/2*2^k with k<=5 MAGICs would span
+ * the area up to 2^(11-k)+ADDOFFSET. For k=4 this give optimal
+ * ADDOFFSET as -7..0. For k=3 ADDOFFSET can go up to 4 (with tiny
+ * savings for negative ADDOFFSET). For k=5 ADDOFFSET can go -1..16
+ * (with no savings for negative values).
+ *
+ * In particular, keeping ADDOFFSET 0 for sizes of chunks up to 2^6
+ * leads to tiny pessimizations in case of sizes 4, 8, 12, 24, and
+ * leads to no contradictions except for size=80 (or 96.)
+ *
+ * However, it also makes sense to keep no magic for sizes 48 or less.
+ * This is what we do. In this case one needs ADDOFFSET>=1 also for
+ * chunksizes 12, 24, and 48, unless one gets one less chunk per
+ * arena.
+ *
+ * The algo of OV_MAGIC(block,bucket) keeps ADDOFFSET 0 until
+ * chunksize of 64, then makes it 1.
+ *
+ * This allows for an additional optimization: the above scheme leads
+ * to giant overheads for sizes 128 or more (one whole chunk needs to
+ * be sacrifised to keep INDEX). Instead we use chunks not of size
+ * 2^k, but of size 2^k-ALIGN. If we pack these chunks at the end of
+ * the arena, then the beginnings are still in different 2^k-long
+ * sections of the arena if k>=7 for ALIGN==4, and k>=8 if ALIGN=8.
+ * Thus for k>7 the above algo of calculating the offset of the magic
+ * will still give different answers for different chunks. And to
+ * avoid the overrun of MAGIC1 into INDEX, one needs ADDOFFSET of >=1.
+ * In the case k=7 we just move the first chunk an extra ALIGN
+ * backward inside the ARENA (this is done once per arena lifetime,
+ * thus is not a big overhead). */
+# define MAX_PACKED_POW2 6
+# define MAX_PACKED (MAX_PACKED_POW2 * BUCKETS_PER_POW2 + BUCKET_POW2_SHIFT)
+# define MAX_POW2_ALGO ((1<<(MAX_PACKED_POW2 + 1)) - M_OVERHEAD)
+# define TWOK_MASK ((1<<LOG_OF_MIN_ARENA) - 1)
+# define TWOK_MASKED(x) (PTR2UV(x) & ~TWOK_MASK)
+# define TWOK_SHIFT(x) (PTR2UV(x) & TWOK_MASK)
+# define OV_INDEXp(block) (INT2PTR(u_char*,TWOK_MASKED(block)))
# define OV_INDEX(block) (*OV_INDEXp(block))
# define OV_MAGIC(block,bucket) (*(OV_INDEXp(block) + \
- (TWOK_SHIFT(block)>>(bucket + 3)) + \
- (bucket > MAX_NONSHIFT ? 1 : 0)))
+ (TWOK_SHIFT(block)>> \
+ (bucket>>BUCKET_POW2_SHIFT)) + \
+ (bucket >= MIN_NEEDS_SHIFT ? 1 : 0)))
+ /* A bucket can have a shift smaller than it size, we need to
+ shift its magic number so it will not overwrite index: */
+# ifdef BUCKETS_ROOT2
+# define MIN_NEEDS_SHIFT (7*BUCKETS_PER_POW2 - 1) /* Shift 80 greater than chunk 64. */
+# else
+# define MIN_NEEDS_SHIFT (7*BUCKETS_PER_POW2) /* Shift 128 greater than chunk 32. */
+# endif
# define CHUNK_SHIFT 0
-static u_char n_blks[11 - 3] = {224, 120, 62, 31, 16, 8, 4, 2};
-static u_short blk_shift[11 - 3] = {256, 128, 64, 32,
- 16*sizeof(union overhead),
- 8*sizeof(union overhead),
- 4*sizeof(union overhead),
- 2*sizeof(union overhead),
-# define MAX_NONSHIFT 2 /* Shift 64 greater than chunk 32. */
-};
+/* Number of active buckets of given ordinal. */
+#ifdef IGNORE_SMALL_BAD_FREE
+#define FIRST_BUCKET_WITH_CHECK (6 * BUCKETS_PER_POW2) /* 64 */
+# define N_BLKS(bucket) ( (bucket) < FIRST_BUCKET_WITH_CHECK \
+ ? ((1<<LOG_OF_MIN_ARENA) - 1)/BUCKET_SIZE(bucket) \
+ : n_blks[bucket] )
+#else
+# define N_BLKS(bucket) n_blks[bucket]
+#endif
+
+static u_short n_blks[LOG_OF_MIN_ARENA * BUCKETS_PER_POW2] =
+ {
+# if BUCKETS_PER_POW2==1
+ 0, 0,
+ (MIN_BUC_POW2==2 ? 384 : 0),
+ 224, 120, 62, 31, 16, 8, 4, 2
+# else
+ 0, 0, 0, 0,
+ (MIN_BUC_POW2==2 ? 384 : 0), (MIN_BUC_POW2==2 ? 384 : 0), /* 4, 4 */
+ 224, 149, 120, 80, 62, 41, 31, 25, 16, 16, 8, 8, 4, 4, 2, 2
+# endif
+ };
+
+/* Shift of the first bucket with the given ordinal inside 2K chunk. */
+#ifdef IGNORE_SMALL_BAD_FREE
+# define BLK_SHIFT(bucket) ( (bucket) < FIRST_BUCKET_WITH_CHECK \
+ ? ((1<<LOG_OF_MIN_ARENA) \
+ - BUCKET_SIZE(bucket) * N_BLKS(bucket)) \
+ : blk_shift[bucket])
+#else
+# define BLK_SHIFT(bucket) blk_shift[bucket]
+#endif
+
+static u_short blk_shift[LOG_OF_MIN_ARENA * BUCKETS_PER_POW2] =
+ {
+# if BUCKETS_PER_POW2==1
+ 0, 0,
+ (MIN_BUC_POW2==2 ? 512 : 0),
+ 256, 128, 64, 64, /* 8 to 64 */
+ 16*sizeof(union overhead),
+ 8*sizeof(union overhead),
+ 4*sizeof(union overhead),
+ 2*sizeof(union overhead),
+# else
+ 0, 0, 0, 0,
+ (MIN_BUC_POW2==2 ? 512 : 0), (MIN_BUC_POW2==2 ? 512 : 0),
+ 256, 260, 128, 128, 64, 80, 64, 48, /* 8 to 96 */
+ 16*sizeof(union overhead), 16*sizeof(union overhead),
+ 8*sizeof(union overhead), 8*sizeof(union overhead),
+ 4*sizeof(union overhead), 4*sizeof(union overhead),
+ 2*sizeof(union overhead), 2*sizeof(union overhead),
+# endif
+ };
+
+# define NEEDED_ALIGNMENT 0x800 /* 2k boundaries */
+# define WANTED_ALIGNMENT 0x800 /* 2k boundaries */
#else /* !PACK_MALLOC */
# define OV_MAGIC(block,bucket) (block)->ov_magic
# define OV_INDEX(block) (block)->ov_index
# define CHUNK_SHIFT 1
+# define MAX_PACKED -1
+# define NEEDED_ALIGNMENT MEM_ALIGNBYTES
+# define WANTED_ALIGNMENT 0x400 /* 1k boundaries */
+
#endif /* !PACK_MALLOC */
-# define M_OVERHEAD (sizeof(union overhead) + RSLOP)
+#define M_OVERHEAD (sizeof(union overhead) + RSLOP)
+
+#ifdef PACK_MALLOC
+# define MEM_OVERHEAD(bucket) \
+ (bucket <= MAX_PACKED ? 0 : M_OVERHEAD)
+# ifdef SMALL_BUCKET_VIA_TABLE
+# define START_SHIFTS_BUCKET ((MAX_PACKED_POW2 + 1) * BUCKETS_PER_POW2)
+# define START_SHIFT MAX_PACKED_POW2
+# ifdef BUCKETS_ROOT2 /* Chunks of size 3*2^n. */
+# define SIZE_TABLE_MAX 80
+# else
+# define SIZE_TABLE_MAX 64
+# endif
+static char bucket_of[] =
+ {
+# ifdef BUCKETS_ROOT2 /* Chunks of size 3*2^n. */
+ /* 0 to 15 in 4-byte increments. */
+ (sizeof(void*) > 4 ? 6 : 5), /* 4/8, 5-th bucket for better reports */
+ 6, /* 8 */
+ IF_ALIGN_8(8,7), 8, /* 16/12, 16 */
+ 9, 9, 10, 10, /* 24, 32 */
+ 11, 11, 11, 11, /* 48 */
+ 12, 12, 12, 12, /* 64 */
+ 13, 13, 13, 13, /* 80 */
+ 13, 13, 13, 13 /* 80 */
+# else /* !BUCKETS_ROOT2 */
+ /* 0 to 15 in 4-byte increments. */
+ (sizeof(void*) > 4 ? 3 : 2),
+ 3,
+ 4, 4,
+ 5, 5, 5, 5,
+ 6, 6, 6, 6,
+ 6, 6, 6, 6
+# endif /* !BUCKETS_ROOT2 */
+ };
+# else /* !SMALL_BUCKET_VIA_TABLE */
+# define START_SHIFTS_BUCKET MIN_BUCKET
+# define START_SHIFT (MIN_BUC_POW2 - 1)
+# endif /* !SMALL_BUCKET_VIA_TABLE */
+#else /* !PACK_MALLOC */
+# define MEM_OVERHEAD(bucket) M_OVERHEAD
+# ifdef SMALL_BUCKET_VIA_TABLE
+# undef SMALL_BUCKET_VIA_TABLE
+# endif
+# define START_SHIFTS_BUCKET MIN_BUCKET
+# define START_SHIFT (MIN_BUC_POW2 - 1)
+#endif /* !PACK_MALLOC */
/*
* Big allocations are often of the size 2^n bytes. To make them a
# ifndef PERL_PAGESIZE
# define PERL_PAGESIZE 4096
# endif
-# ifndef FIRST_BIG_TWO_POT
-# define FIRST_BIG_TWO_POT 14 /* 16K */
+# ifndef FIRST_BIG_POW2
+# define FIRST_BIG_POW2 15 /* 32K, 16K is used too often. */
# endif
-# define FIRST_BIG_BLOCK (1<<FIRST_BIG_TWO_POT) /* 16K */
+# define FIRST_BIG_BLOCK (1<<FIRST_BIG_POW2)
/* If this value or more, check against bigger blocks. */
# define FIRST_BIG_BOUND (FIRST_BIG_BLOCK - M_OVERHEAD)
/* If less than this value, goes into 2^n-overhead-block. */
# define LAST_SMALL_BOUND ((FIRST_BIG_BLOCK>>1) - M_OVERHEAD)
-#endif /* TWO_POT_OPTIMIZE */
+# define POW2_OPTIMIZE_ADJUST(nbytes) \
+ ((nbytes >= FIRST_BIG_BOUND) ? nbytes -= PERL_PAGESIZE : 0)
+# define POW2_OPTIMIZE_SURPLUS(bucket) \
+ ((bucket >= FIRST_BIG_POW2 * BUCKETS_PER_POW2) ? PERL_PAGESIZE : 0)
+
+#else /* !TWO_POT_OPTIMIZE */
+# define POW2_OPTIMIZE_ADJUST(nbytes)
+# define POW2_OPTIMIZE_SURPLUS(bucket) 0
+#endif /* !TWO_POT_OPTIMIZE */
+
+#if defined(HAS_64K_LIMIT) && defined(PERL_CORE)
+# define BARK_64K_LIMIT(what,nbytes,size) \
+ if (nbytes > 0xffff) { \
+ PerlIO_printf(PerlIO_stderr(), \
+ "%s too large: %lx\n", what, size); \
+ my_exit(1); \
+ }
+#else /* !HAS_64K_LIMIT || !PERL_CORE */
+# define BARK_64K_LIMIT(what,nbytes,size)
+#endif /* !HAS_64K_LIMIT || !PERL_CORE */
-#if defined(PERL_EMERGENCY_SBRK) && defined(PERL_CORE)
+#ifndef MIN_SBRK
+# define MIN_SBRK 2048
+#endif
+
+#ifndef FIRST_SBRK
+# define FIRST_SBRK (48*1024)
+#endif
+
+/* Minimal sbrk in percents of what is already alloced. */
+#ifndef MIN_SBRK_FRAC
+# define MIN_SBRK_FRAC 3
+#endif
+
+#ifndef SBRK_ALLOW_FAILURES
+# define SBRK_ALLOW_FAILURES 3
+#endif
-#ifndef BIG_SIZE
-# define BIG_SIZE (1<<16) /* 64K */
+#ifndef SBRK_FAILURE_PRICE
+# define SBRK_FAILURE_PRICE 50
#endif
+static void morecore (register int bucket);
+# if defined(DEBUGGING)
+static void botch (char *diag, char *s);
+# endif
+static void add_to_chain (void *p, MEM_SIZE size, MEM_SIZE chip);
+static void* get_from_chain (MEM_SIZE size);
+static void* get_from_bigger_buckets(int bucket, MEM_SIZE size);
+static union overhead *getpages (MEM_SIZE needed, int *nblksp, int bucket);
+static int getpages_adjacent(MEM_SIZE require);
+
+#if defined(PERL_EMERGENCY_SBRK) && defined(PERL_CORE)
+
+# ifndef BIG_SIZE
+# define BIG_SIZE (1<<16) /* 64K */
+# endif
+
+#ifdef I_MACH_CTHREADS
+# undef MUTEX_LOCK
+# define MUTEX_LOCK(m) STMT_START { if (*m) mutex_lock(*m); } STMT_END
+# undef MUTEX_UNLOCK
+# define MUTEX_UNLOCK(m) STMT_START { if (*m) mutex_unlock(*m); } STMT_END
+#endif
+
static char *emergency_buffer;
static MEM_SIZE emergency_buffer_size;
-static char *
-emergency_sbrk(size)
- MEM_SIZE size;
+static Malloc_t
+emergency_sbrk(MEM_SIZE size)
{
+ MEM_SIZE rsize = (((size - 1)>>LOG_OF_MIN_ARENA) + 1)<<LOG_OF_MIN_ARENA;
+
if (size >= BIG_SIZE) {
/* Give the possibility to recover: */
- die("Out of memory during request for %i bytes", size);
- /* croak may eat too much memory. */
+ MALLOC_UNLOCK;
+ croak("Out of memory during \"large\" request for %i bytes", size);
}
- if (!emergency_buffer) {
+ if (emergency_buffer_size >= rsize) {
+ char *old = emergency_buffer;
+
+ emergency_buffer_size -= rsize;
+ emergency_buffer += rsize;
+ return old;
+ } else {
+ dTHX;
/* First offense, give a possibility to recover by dieing. */
/* No malloc involved here: */
- GV **gvp = (GV**)hv_fetch(defstash, "^M", 2, 0);
+ GV **gvp = (GV**)hv_fetch(PL_defstash, "^M", 2, 0);
SV *sv;
char *pv;
-
- if (!gvp) gvp = (GV**)hv_fetch(defstash, "\015", 1, 0);
+ int have = 0;
+ STRLEN n_a;
+
+ if (emergency_buffer_size) {
+ add_to_chain(emergency_buffer, emergency_buffer_size, 0);
+ emergency_buffer_size = 0;
+ emergency_buffer = Nullch;
+ have = 1;
+ }
+ if (!gvp) gvp = (GV**)hv_fetch(PL_defstash, "\015", 1, 0);
if (!gvp || !(sv = GvSV(*gvp)) || !SvPOK(sv)
- || (SvLEN(sv) < (1<<11) - M_OVERHEAD))
+ || (SvLEN(sv) < (1<<LOG_OF_MIN_ARENA) - M_OVERHEAD)) {
+ if (have)
+ goto do_croak;
return (char *)-1; /* Now die die die... */
-
+ }
/* Got it, now detach SvPV: */
- pv = SvPV(sv, na);
+ pv = SvPV(sv, n_a);
/* Check alignment: */
- if (((u_int)(pv - M_OVERHEAD)) & ((1<<11) - 1)) {
+ if ((PTR2UV(pv) - sizeof(union overhead)) & (NEEDED_ALIGNMENT - 1)) {
PerlIO_puts(PerlIO_stderr(),"Bad alignment of $^M!\n");
return (char *)-1; /* die die die */
}
- emergency_buffer = pv - M_OVERHEAD;
- emergency_buffer_size = SvLEN(sv) + M_OVERHEAD;
+ emergency_buffer = pv - sizeof(union overhead);
+ emergency_buffer_size = malloced_size(pv) + M_OVERHEAD;
SvPOK_off(sv);
- SvREADONLY_on(sv);
- die("Out of memory!"); /* croak may eat too much memory. */
- }
- else if (emergency_buffer_size >= size) {
- emergency_buffer_size -= size;
- return emergency_buffer + emergency_buffer_size;
+ SvPVX(sv) = Nullch;
+ SvCUR(sv) = SvLEN(sv) = 0;
}
-
- return (char *)-1; /* poor guy... */
+ do_croak:
+ MALLOC_UNLOCK;
+ croak("Out of memory during request for %i bytes", size);
+ /* NOTREACHED */
+ return Nullch;
}
-#else /* !(defined(TWO_POT_OPTIMIZE) && defined(PERL_CORE)) */
+#else /* !(defined(PERL_EMERGENCY_SBRK) && defined(PERL_CORE)) */
# define emergency_sbrk(size) -1
-#endif /* !(defined(TWO_POT_OPTIMIZE) && defined(PERL_CORE)) */
+#endif /* !(defined(PERL_EMERGENCY_SBRK) && defined(PERL_CORE)) */
+
+#ifndef BITS_IN_PTR
+# define BITS_IN_PTR (8*PTRSIZE)
+#endif
/*
- * nextf[i] is the pointer to the next free block of size 2^(i+3). The
+ * nextf[i] is the pointer to the next free block of size 2^i. The
* smallest allocatable block is 8 bytes. The overhead information
* precedes the data area returned to the user.
*/
-#define NBUCKETS 30
+#define NBUCKETS (BITS_IN_PTR*BUCKETS_PER_POW2 + 1)
static union overhead *nextf[NBUCKETS];
+#if defined(PURIFY) && !defined(USE_PERL_SBRK)
+# define USE_PERL_SBRK
+#endif
+
#ifdef USE_PERL_SBRK
#define sbrk(a) Perl_sbrk(a)
-char * Perl_sbrk _((int size));
+Malloc_t Perl_sbrk (int size);
+#else
+#ifdef DONT_DECLARE_STD
+#ifdef I_UNISTD
+#include <unistd.h>
+#endif
#else
-extern char *sbrk();
+extern Malloc_t sbrk(int);
+#endif
#endif
#ifdef DEBUGGING_MSTATS
* for a given block size.
*/
static u_int nmalloc[NBUCKETS];
-static u_int goodsbrk;
static u_int sbrk_slack;
static u_int start_slack;
#endif
+static u_int goodsbrk;
+
#ifdef DEBUGGING
-#define ASSERT(p) if (!(p)) botch(STRINGIFY(p)); else
+#undef ASSERT
+#define ASSERT(p,diag) if (!(p)) botch(diag,STRINGIFY(p)); else
static void
-botch(s)
- char *s;
+botch(char *diag, char *s)
{
- PerlIO_printf(PerlIO_stderr(), "assertion botched: %s\n", s);
- abort();
+ dTHX;
+ PerlIO_printf(PerlIO_stderr(), "assertion botched (%s?): %s\n", diag, s);
+ PerlProc_abort();
}
#else
-#define ASSERT(p)
+#define ASSERT(p, diag)
#endif
Malloc_t
-malloc(nbytes)
- register MEM_SIZE nbytes;
+Perl_malloc(register size_t nbytes)
{
register union overhead *p;
- register int bucket = 0;
+ register int bucket;
register MEM_SIZE shiftr;
#if defined(DEBUGGING) || defined(RCHECK)
MEM_SIZE size = nbytes;
#endif
-#ifdef PERL_CORE
-#ifdef HAS_64K_LIMIT
- if (nbytes > 0xffff) {
- PerlIO_printf(PerlIO_stderr(),
- "Allocation too large: %lx\n", (long)nbytes);
- my_exit(1);
- }
-#endif /* HAS_64K_LIMIT */
+ BARK_64K_LIMIT("Allocation",nbytes,nbytes);
#ifdef DEBUGGING
if ((long)nbytes < 0)
- croak("panic: malloc");
+ croak("%s", "panic: malloc");
#endif
-#endif /* PERL_CORE */
- MUTEX_LOCK(&malloc_mutex);
/*
* Convert amount of memory requested into
* closest block size stored in hash buckets
* space used per block for accounting.
*/
#ifdef PACK_MALLOC
+# ifdef SMALL_BUCKET_VIA_TABLE
+ if (nbytes == 0)
+ bucket = MIN_BUCKET;
+ else if (nbytes <= SIZE_TABLE_MAX) {
+ bucket = bucket_of[(nbytes - 1) >> BUCKET_TABLE_SHIFT];
+ } else
+# else
if (nbytes == 0)
nbytes = 1;
- else if (nbytes > MAX_2_POT_ALGO)
-#endif
- {
-#ifdef TWO_POT_OPTIMIZE
- if (nbytes >= FIRST_BIG_BOUND)
- nbytes -= PERL_PAGESIZE;
+ if (nbytes <= MAX_POW2_ALGO) goto do_shifts;
+ else
+# endif
#endif
- nbytes += M_OVERHEAD;
- nbytes = (nbytes + 3) &~ 3;
+ {
+ POW2_OPTIMIZE_ADJUST(nbytes);
+ nbytes += M_OVERHEAD;
+ nbytes = (nbytes + 3) &~ 3;
+ do_shifts:
+ shiftr = (nbytes - 1) >> START_SHIFT;
+ bucket = START_SHIFTS_BUCKET;
+ /* apart from this loop, this is O(1) */
+ while (shiftr >>= 1)
+ bucket += BUCKETS_PER_POW2;
}
- shiftr = (nbytes - 1) >> 2;
- /* apart from this loop, this is O(1) */
- while (shiftr >>= 1)
- bucket++;
+ MALLOC_LOCK;
/*
* If nothing in hash bucket right now,
* request more memory from the system.
*/
if (nextf[bucket] == NULL)
morecore(bucket);
- if ((p = (union overhead *)nextf[bucket]) == NULL) {
- MUTEX_UNLOCK(&malloc_mutex);
+ if ((p = nextf[bucket]) == NULL) {
+ MALLOC_UNLOCK;
#ifdef PERL_CORE
- if (!nomemok) {
- PerlIO_puts(PerlIO_stderr(),"Out of memory!\n");
- my_exit(1);
+ {
+ dTHX;
+ if (!PL_nomemok) {
+ PerlIO_puts(PerlIO_stderr(),"Out of memory!\n");
+ my_exit(1);
+ }
}
-#else
- return (NULL);
#endif
+ return (NULL);
}
-#ifdef PERL_CORE
- DEBUG_m(PerlIO_printf(Perl_debug_log, "0x%lx: (%05lu) malloc %ld bytes\n",
- (unsigned long)(p+1),(unsigned long)(an++),(long)size));
-#endif /* PERL_CORE */
+ DEBUG_m(PerlIO_printf(Perl_debug_log,
+ "0x%"UVxf": (%05lu) malloc %ld bytes\n",
+ PTR2UV(p+1), (unsigned long)(PL_an++),
+ (long)size));
/* remove from linked list */
-#ifdef RCHECK
- if (*((int*)p) & (sizeof(union overhead) - 1))
- PerlIO_printf(PerlIO_stderr(), "Corrupt malloc ptr 0x%lx at 0x%lx\n",
- (unsigned long)*((int*)p),(unsigned long)p);
+#if defined(RCHECK)
+ if ((PTR2UV(p)) & (MEM_ALIGNBYTES - 1)) {
+ dTHX;
+ PerlIO_printf(PerlIO_stderr(),
+ "Unaligned pointer in the free chain 0x%"UVxf"\n",
+ PTR2UV(p));
+ }
+ if ((PTR2UV(p->ov_next)) & (MEM_ALIGNBYTES - 1)) {
+ dTHX;
+ PerlIO_printf(PerlIO_stderr(),
+ "Unaligned `next' pointer in the free "
+ "chain 0x"UVxf" at 0x%"UVxf"\n",
+ PTR2UV(p->ov_next), PTR2UV(p));
+ }
#endif
nextf[bucket] = p->ov_next;
- OV_MAGIC(p, bucket) = MAGIC;
+
+ MALLOC_UNLOCK;
+
+#ifdef IGNORE_SMALL_BAD_FREE
+ if (bucket >= FIRST_BUCKET_WITH_CHECK)
+#endif
+ OV_MAGIC(p, bucket) = MAGIC;
#ifndef PACK_MALLOC
OV_INDEX(p) = bucket;
#endif
* Record allocated size of block and
* bound space with magic numbers.
*/
- nbytes = (size + M_OVERHEAD + 3) &~ 3;
- if (nbytes <= 0x10000)
- p->ov_size = nbytes - 1;
p->ov_rmagic = RMAGIC;
- *((u_int *)((caddr_t)p + nbytes - RSLOP)) = RMAGIC;
+ if (bucket <= MAX_SHORT_BUCKET) {
+ int i;
+
+ nbytes = size + M_OVERHEAD;
+ p->ov_size = nbytes - 1;
+ if ((i = nbytes & 3)) {
+ i = 4 - i;
+ while (i--)
+ *((char *)((caddr_t)p + nbytes - RSLOP + i)) = RMAGIC_C;
+ }
+ nbytes = (nbytes + 3) &~ 3;
+ *((u_int *)((caddr_t)p + nbytes - RSLOP)) = RMAGIC;
+ }
#endif
- MUTEX_UNLOCK(&malloc_mutex);
return ((Malloc_t)(p + CHUNK_SHIFT));
}
-/*
- * Allocate more memory to the indicated bucket.
- */
+static char *last_sbrk_top;
+static char *last_op; /* This arena can be easily extended. */
+static int sbrked_remains;
+static int sbrk_good = SBRK_ALLOW_FAILURES * SBRK_FAILURE_PRICE;
+
+#ifdef DEBUGGING_MSTATS
+static int sbrks;
+#endif
+
+struct chunk_chain_s {
+ struct chunk_chain_s *next;
+ MEM_SIZE size;
+};
+static struct chunk_chain_s *chunk_chain;
+static int n_chunks;
+static char max_bucket;
+
+/* Cutoff a piece of one of the chunks in the chain. Prefer smaller chunk. */
+static void *
+get_from_chain(MEM_SIZE size)
+{
+ struct chunk_chain_s *elt = chunk_chain, **oldp = &chunk_chain;
+ struct chunk_chain_s **oldgoodp = NULL;
+ long min_remain = LONG_MAX;
+
+ while (elt) {
+ if (elt->size >= size) {
+ long remains = elt->size - size;
+ if (remains >= 0 && remains < min_remain) {
+ oldgoodp = oldp;
+ min_remain = remains;
+ }
+ if (remains == 0) {
+ break;
+ }
+ }
+ oldp = &( elt->next );
+ elt = elt->next;
+ }
+ if (!oldgoodp) return NULL;
+ if (min_remain) {
+ void *ret = *oldgoodp;
+ struct chunk_chain_s *next = (*oldgoodp)->next;
+
+ *oldgoodp = (struct chunk_chain_s *)((char*)ret + size);
+ (*oldgoodp)->size = min_remain;
+ (*oldgoodp)->next = next;
+ return ret;
+ } else {
+ void *ret = *oldgoodp;
+ *oldgoodp = (*oldgoodp)->next;
+ n_chunks--;
+ return ret;
+ }
+}
+
static void
-morecore(bucket)
- register int bucket;
+add_to_chain(void *p, MEM_SIZE size, MEM_SIZE chip)
{
- register union overhead *ovp;
- register int rnu; /* 2^rnu bytes will be requested */
- register int nblks; /* become nblks blocks of the desired size */
- register MEM_SIZE siz, needed;
- int slack = 0;
+ struct chunk_chain_s *next = chunk_chain;
+ char *cp = (char*)p;
+
+ cp += chip;
+ chunk_chain = (struct chunk_chain_s *)cp;
+ chunk_chain->size = size - chip;
+ chunk_chain->next = next;
+ n_chunks++;
+}
- if (nextf[bucket])
- return;
- if (bucket == (sizeof(MEM_SIZE)*8 - 3)) {
- croak("Allocation too large");
+static void *
+get_from_bigger_buckets(int bucket, MEM_SIZE size)
+{
+ int price = 1;
+ static int bucketprice[NBUCKETS];
+ while (bucket <= max_bucket) {
+ /* We postpone stealing from bigger buckets until we want it
+ often enough. */
+ if (nextf[bucket] && bucketprice[bucket]++ >= price) {
+ /* Steal it! */
+ void *ret = (void*)(nextf[bucket] - 1 + CHUNK_SHIFT);
+ bucketprice[bucket] = 0;
+ if (((char*)nextf[bucket]) - M_OVERHEAD == last_op) {
+ last_op = NULL; /* Disable optimization */
+ }
+ nextf[bucket] = nextf[bucket]->ov_next;
+#ifdef DEBUGGING_MSTATS
+ nmalloc[bucket]--;
+ start_slack -= M_OVERHEAD;
+#endif
+ add_to_chain(ret, (BUCKET_SIZE(bucket) +
+ POW2_OPTIMIZE_SURPLUS(bucket)),
+ size);
+ return ret;
}
- /*
- * Insure memory is allocated
- * on a page boundary. Should
- * make getpageize call?
- */
-#ifndef atarist /* on the atari we dont have to worry about this */
- ovp = (union overhead *)sbrk(0);
-# ifndef I286
- if ((UV)ovp & (0x7FF >> CHUNK_SHIFT)) {
- slack = (0x800 >> CHUNK_SHIFT) - ((UV)ovp & (0x7FF >> CHUNK_SHIFT));
- (void)sbrk(slack);
-# if defined(DEBUGGING_MSTATS)
- sbrk_slack += slack;
-# endif
+ bucket++;
+ }
+ return NULL;
+}
+
+static union overhead *
+getpages(MEM_SIZE needed, int *nblksp, int bucket)
+{
+ /* Need to do (possibly expensive) system call. Try to
+ optimize it for rare calling. */
+ MEM_SIZE require = needed - sbrked_remains;
+ char *cp;
+ union overhead *ovp;
+ MEM_SIZE slack = 0;
+
+ if (sbrk_good > 0) {
+ if (!last_sbrk_top && require < FIRST_SBRK)
+ require = FIRST_SBRK;
+ else if (require < MIN_SBRK) require = MIN_SBRK;
+
+ if (require < goodsbrk * MIN_SBRK_FRAC / 100)
+ require = goodsbrk * MIN_SBRK_FRAC / 100;
+ require = ((require - 1 + MIN_SBRK) / MIN_SBRK) * MIN_SBRK;
+ } else {
+ require = needed;
+ last_sbrk_top = 0;
+ sbrked_remains = 0;
+ }
+
+ DEBUG_m(PerlIO_printf(Perl_debug_log,
+ "sbrk(%ld) for %ld-byte-long arena\n",
+ (long)require, (long) needed));
+ cp = (char *)sbrk(require);
+#ifdef DEBUGGING_MSTATS
+ sbrks++;
+#endif
+ if (cp == last_sbrk_top) {
+ /* Common case, anything is fine. */
+ sbrk_good++;
+ ovp = (union overhead *) (cp - sbrked_remains);
+ last_op = cp - sbrked_remains;
+ sbrked_remains = require - (needed - sbrked_remains);
+ } else if (cp == (char *)-1) { /* no more room! */
+ ovp = (union overhead *)emergency_sbrk(needed);
+ if (ovp == (union overhead *)-1)
+ return 0;
+ if (((char*)ovp) > last_op) { /* Cannot happen with current emergency_sbrk() */
+ last_op = 0;
+ }
+ return ovp;
+ } else { /* Non-continuous or first sbrk(). */
+ long add = sbrked_remains;
+ char *newcp;
+
+ if (sbrked_remains) { /* Put rest into chain, we
+ cannot use it right now. */
+ add_to_chain((void*)(last_sbrk_top - sbrked_remains),
+ sbrked_remains, 0);
}
-# else
- /* The sbrk(0) call on the I286 always returns the next segment */
-# endif
-#endif /* atarist */
-#if !(defined(I286) || defined(atarist))
- /* take 2k unless the block is bigger than that */
- rnu = (bucket <= 8) ? 11 : bucket + 3;
-#else
- /* take 16k unless the block is bigger than that
- (80286s like large segments!), probably good on the atari too */
- rnu = (bucket <= 11) ? 14 : bucket + 3;
+ /* Second, check alignment. */
+ slack = 0;
+
+#if !defined(atarist) && !defined(__MINT__) /* on the atari we dont have to worry about this */
+# ifndef I286 /* The sbrk(0) call on the I286 always returns the next segment */
+ /* WANTED_ALIGNMENT may be more than NEEDED_ALIGNMENT, but this may
+ improve performance of memory access. */
+ if (PTR2UV(cp) & (WANTED_ALIGNMENT - 1)) { /* Not aligned. */
+ slack = WANTED_ALIGNMENT - (PTR2UV(cp) & (WANTED_ALIGNMENT - 1));
+ add += slack;
+ }
+# endif
+#endif /* !atarist && !MINT */
+
+ if (add) {
+ DEBUG_m(PerlIO_printf(Perl_debug_log,
+ "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",
+ (long)add, (long) slack,
+ (long) sbrked_remains));
+ newcp = (char *)sbrk(add);
+#if defined(DEBUGGING_MSTATS)
+ sbrks++;
+ sbrk_slack += add;
#endif
- nblks = 1 << (rnu - (bucket + 3)); /* how many blocks to get */
- needed = (MEM_SIZE)1 << rnu;
-#ifdef TWO_POT_OPTIMIZE
- needed += (bucket >= (FIRST_BIG_TWO_POT - 3) ? PERL_PAGESIZE : 0);
+ if (newcp != cp + require) {
+ /* Too bad: even rounding sbrk() is not continuous.*/
+ DEBUG_m(PerlIO_printf(Perl_debug_log,
+ "failed to fix bad sbrk()\n"));
+#ifdef PACK_MALLOC
+ if (slack) {
+ MALLOC_UNLOCK;
+ fatalcroak("panic: Off-page sbrk\n");
+ }
+#endif
+ if (sbrked_remains) {
+ /* Try again. */
+#if defined(DEBUGGING_MSTATS)
+ sbrk_slack += require;
+#endif
+ require = needed;
+ DEBUG_m(PerlIO_printf(Perl_debug_log,
+ "straight sbrk(%ld)\n",
+ (long)require));
+ cp = (char *)sbrk(require);
+#ifdef DEBUGGING_MSTATS
+ sbrks++;
#endif
- ovp = (union overhead *)sbrk(needed);
- /* no more room! */
- if (ovp == (union overhead *)-1) {
- ovp = (union overhead *)emergency_sbrk(needed);
- if (ovp == (union overhead *)-1)
- return;
+ if (cp == (char *)-1)
+ return 0;
+ }
+ sbrk_good = -1; /* Disable optimization!
+ Continue with not-aligned... */
+ } else {
+ cp += slack;
+ require += sbrked_remains;
+ }
}
-#ifdef DEBUGGING_MSTATS
- goodsbrk += needed;
-#endif
+
+ if (last_sbrk_top) {
+ sbrk_good -= SBRK_FAILURE_PRICE;
+ }
+
+ ovp = (union overhead *) cp;
/*
* Round up to minimum allocation size boundary
* and deduct from block count to reflect.
*/
-#ifndef I286
-# ifdef PACK_MALLOC
- if ((UV)ovp & 0x7FF)
- croak("panic: Off-page sbrk");
+
+# if NEEDED_ALIGNMENT > MEM_ALIGNBYTES
+ if (PTR2UV(ovp) & (NEEDED_ALIGNMENT - 1))
+ fatalcroak("Misalignment of sbrk()\n");
+ else
# endif
- if ((UV)ovp & 7) {
- ovp = (union overhead *)(((UV)ovp + 8) & ~7);
- nblks--;
- }
-#else
- /* Again, this should always be ok on an 80286 */
+#ifndef I286 /* Again, this should always be ok on an 80286 */
+ if (PTR2UV(ovp) & (MEM_ALIGNBYTES - 1)) {
+ DEBUG_m(PerlIO_printf(Perl_debug_log,
+ "fixing sbrk(): %d bytes off machine alignement\n",
+ (int)(PTR2UV(ovp) & (MEM_ALIGNBYTES - 1))));
+ ovp = INT2PTR(union overhead *,(PTR2UV(ovp) + MEM_ALIGNBYTES) &
+ (MEM_ALIGNBYTES - 1));
+ (*nblksp)--;
+# if defined(DEBUGGING_MSTATS)
+ /* This is only approx. if TWO_POT_OPTIMIZE: */
+ sbrk_slack += (1 << (bucket >> BUCKET_POW2_SHIFT));
+# endif
+ }
#endif
+ ; /* Finish `else' */
+ sbrked_remains = require - needed;
+ last_op = cp;
+ }
+ last_sbrk_top = cp + require;
+#ifdef DEBUGGING_MSTATS
+ goodsbrk += require;
+#endif
+ return ovp;
+}
+
+static int
+getpages_adjacent(MEM_SIZE require)
+{
+ if (require <= sbrked_remains) {
+ sbrked_remains -= require;
+ } else {
+ char *cp;
+
+ require -= sbrked_remains;
+ /* We do not try to optimize sbrks here, we go for place. */
+ cp = (char*) sbrk(require);
+#ifdef DEBUGGING_MSTATS
+ sbrks++;
+ goodsbrk += require;
+#endif
+ if (cp == last_sbrk_top) {
+ sbrked_remains = 0;
+ last_sbrk_top = cp + require;
+ } else {
+ if (cp == (char*)-1) { /* Out of memory */
+#ifdef DEBUGGING_MSTATS
+ goodsbrk -= require;
+#endif
+ return 0;
+ }
+ /* Report the failure: */
+ if (sbrked_remains)
+ add_to_chain((void*)(last_sbrk_top - sbrked_remains),
+ sbrked_remains, 0);
+ add_to_chain((void*)cp, require, 0);
+ sbrk_good -= SBRK_FAILURE_PRICE;
+ sbrked_remains = 0;
+ last_sbrk_top = 0;
+ last_op = 0;
+ return 0;
+ }
+ }
+
+ return 1;
+}
+
+/*
+ * Allocate more memory to the indicated bucket.
+ */
+static void
+morecore(register int bucket)
+{
+ register union overhead *ovp;
+ register int rnu; /* 2^rnu bytes will be requested */
+ int nblks; /* become nblks blocks of the desired size */
+ register MEM_SIZE siz, needed;
+
+ if (nextf[bucket])
+ return;
+ if (bucket == sizeof(MEM_SIZE)*8*BUCKETS_PER_POW2) {
+ MALLOC_UNLOCK;
+ croak("%s", "Out of memory during ridiculously large request");
+ }
+ if (bucket > max_bucket)
+ max_bucket = bucket;
+
+ rnu = ( (bucket <= (LOG_OF_MIN_ARENA << BUCKET_POW2_SHIFT))
+ ? LOG_OF_MIN_ARENA
+ : (bucket >> BUCKET_POW2_SHIFT) );
+ /* This may be overwritten later: */
+ nblks = 1 << (rnu - (bucket >> BUCKET_POW2_SHIFT)); /* how many blocks to get */
+ needed = ((MEM_SIZE)1 << rnu) + POW2_OPTIMIZE_SURPLUS(bucket);
+ if (nextf[rnu << BUCKET_POW2_SHIFT]) { /* 2048b bucket. */
+ ovp = nextf[rnu << BUCKET_POW2_SHIFT] - 1 + CHUNK_SHIFT;
+ nextf[rnu << BUCKET_POW2_SHIFT]
+ = nextf[rnu << BUCKET_POW2_SHIFT]->ov_next;
+#ifdef DEBUGGING_MSTATS
+ nmalloc[rnu << BUCKET_POW2_SHIFT]--;
+ start_slack -= M_OVERHEAD;
+#endif
+ DEBUG_m(PerlIO_printf(Perl_debug_log,
+ "stealing %ld bytes from %ld arena\n",
+ (long) needed, (long) rnu << BUCKET_POW2_SHIFT));
+ } else if (chunk_chain
+ && (ovp = (union overhead*) get_from_chain(needed))) {
+ DEBUG_m(PerlIO_printf(Perl_debug_log,
+ "stealing %ld bytes from chain\n",
+ (long) needed));
+ } else if ( (ovp = (union overhead*)
+ get_from_bigger_buckets((rnu << BUCKET_POW2_SHIFT) + 1,
+ needed)) ) {
+ DEBUG_m(PerlIO_printf(Perl_debug_log,
+ "stealing %ld bytes from bigger buckets\n",
+ (long) needed));
+ } else if (needed <= sbrked_remains) {
+ ovp = (union overhead *)(last_sbrk_top - sbrked_remains);
+ sbrked_remains -= needed;
+ last_op = (char*)ovp;
+ } else
+ ovp = getpages(needed, &nblks, bucket);
+
+ if (!ovp)
+ return;
+
/*
* Add new memory allocated to that on
* free list for this hash bucket.
*/
- siz = 1 << (bucket + 3);
+ siz = BUCKET_SIZE(bucket);
#ifdef PACK_MALLOC
*(u_char*)ovp = bucket; /* Fill index. */
- if (bucket <= MAX_PACKED - 3) {
- ovp = (union overhead *) ((char*)ovp + blk_shift[bucket]);
- nblks = n_blks[bucket];
+ if (bucket <= MAX_PACKED) {
+ ovp = (union overhead *) ((char*)ovp + BLK_SHIFT(bucket));
+ nblks = N_BLKS(bucket);
# ifdef DEBUGGING_MSTATS
- start_slack += blk_shift[bucket];
+ start_slack += BLK_SHIFT(bucket);
# endif
- } else if (bucket <= 11 - 1 - 3) {
- ovp = (union overhead *) ((char*)ovp + blk_shift[bucket]);
- /* nblks = n_blks[bucket]; */
+ } else if (bucket < LOG_OF_MIN_ARENA * BUCKETS_PER_POW2) {
+ ovp = (union overhead *) ((char*)ovp + BLK_SHIFT(bucket));
siz -= sizeof(union overhead);
} else ovp++; /* One chunk per block. */
-#endif /* !PACK_MALLOC */
+#endif /* PACK_MALLOC */
nextf[bucket] = ovp;
#ifdef DEBUGGING_MSTATS
nmalloc[bucket] += nblks;
+ if (bucket > MAX_PACKED) {
+ start_slack += M_OVERHEAD * nblks;
+ }
#endif
while (--nblks > 0) {
ovp->ov_next = (union overhead *)((caddr_t)ovp + siz);
/* Not all sbrks return zeroed memory.*/
ovp->ov_next = (union overhead *)NULL;
#ifdef PACK_MALLOC
- if (bucket == 7 - 3) { /* Special case, explanation is above. */
- union overhead *n_op = nextf[7 - 3]->ov_next;
- nextf[7 - 3] = (union overhead *)((caddr_t)nextf[7 - 3]
- - sizeof(union overhead));
- nextf[7 - 3]->ov_next = n_op;
+ if (bucket == 7*BUCKETS_PER_POW2) { /* Special case, explanation is above. */
+ union overhead *n_op = nextf[7*BUCKETS_PER_POW2]->ov_next;
+ nextf[7*BUCKETS_PER_POW2] =
+ (union overhead *)((caddr_t)nextf[7*BUCKETS_PER_POW2]
+ - sizeof(union overhead));
+ nextf[7*BUCKETS_PER_POW2]->ov_next = n_op;
}
#endif /* !PACK_MALLOC */
}
Free_t
-free(mp)
- Malloc_t mp;
-{
+Perl_mfree(void *mp)
+{
register MEM_SIZE size;
register union overhead *ovp;
char *cp = (char*)mp;
u_char bucket;
#endif
-#ifdef PERL_CORE
- DEBUG_m(PerlIO_printf(Perl_debug_log, "0x%lx: (%05lu) free\n",(unsigned long)cp,(unsigned long)(an++)));
-#endif /* PERL_CORE */
+ DEBUG_m(PerlIO_printf(Perl_debug_log,
+ "0x%"UVxf": (%05lu) free\n",
+ PTR2UV(cp), (unsigned long)(PL_an++)));
if (cp == NULL)
return;
ovp = (union overhead *)((caddr_t)cp
- - sizeof (union overhead) * CHUNK_SHIFT);
+ - sizeof (union overhead) * CHUNK_SHIFT);
#ifdef PACK_MALLOC
bucket = OV_INDEX(ovp);
#endif
- if (OV_MAGIC(ovp, bucket) != MAGIC) {
+#ifdef IGNORE_SMALL_BAD_FREE
+ if ((bucket >= FIRST_BUCKET_WITH_CHECK)
+ && (OV_MAGIC(ovp, bucket) != MAGIC))
+#else
+ if (OV_MAGIC(ovp, bucket) != MAGIC)
+#endif
+ {
static int bad_free_warn = -1;
if (bad_free_warn == -1) {
- char *pbf = getenv("PERL_BADFREE");
+ dTHX;
+ char *pbf = PerlEnv_getenv("PERL_BADFREE");
bad_free_warn = (pbf) ? atoi(pbf) : 1;
}
if (!bad_free_warn)
return;
#ifdef RCHECK
+#ifdef PERL_CORE
+ {
+ dTHX;
+ if (!PERL_IS_ALIVE || !PL_curcop || ckWARN_d(WARN_MALLOC))
+ Perl_warner(aTHX_ WARN_MALLOC, "%s free() ignored",
+ ovp->ov_rmagic == RMAGIC - 1 ?
+ "Duplicate" : "Bad");
+ }
+#else
warn("%s free() ignored",
ovp->ov_rmagic == RMAGIC - 1 ? "Duplicate" : "Bad");
+#endif
#else
- warn("Bad free() ignored");
+#ifdef PERL_CORE
+ {
+ dTHX;
+ if (!PERL_IS_ALIVE || !PL_curcop || ckWARN_d(WARN_MALLOC))
+ Perl_warner(aTHX_ WARN_MALLOC, "%s", "Bad free() ignored");
+ }
+#else
+ warn("%s", "Bad free() ignored");
+#endif
#endif
return; /* sanity */
- }
- MUTEX_LOCK(&malloc_mutex);
+ }
#ifdef RCHECK
- ASSERT(ovp->ov_rmagic == RMAGIC);
- if (OV_INDEX(ovp) <= MAX_SHORT_BUCKET)
- ASSERT(*(u_int *)((caddr_t)ovp + ovp->ov_size + 1 - RSLOP) == RMAGIC);
+ ASSERT(ovp->ov_rmagic == RMAGIC, "chunk's head overwrite");
+ if (OV_INDEX(ovp) <= MAX_SHORT_BUCKET) {
+ int i;
+ MEM_SIZE nbytes = ovp->ov_size + 1;
+
+ if ((i = nbytes & 3)) {
+ i = 4 - i;
+ while (i--) {
+ ASSERT(*((char *)((caddr_t)ovp + nbytes - RSLOP + i))
+ == RMAGIC_C, "chunk's tail overwrite");
+ }
+ }
+ nbytes = (nbytes + 3) &~ 3;
+ ASSERT(*(u_int *)((caddr_t)ovp + nbytes - RSLOP) == RMAGIC, "chunk's tail overwrite");
+ }
ovp->ov_rmagic = RMAGIC - 1;
#endif
- ASSERT(OV_INDEX(ovp) < NBUCKETS);
+ ASSERT(OV_INDEX(ovp) < NBUCKETS, "chunk's head overwrite");
size = OV_INDEX(ovp);
+
+ MALLOC_LOCK;
ovp->ov_next = nextf[size];
nextf[size] = ovp;
- MUTEX_UNLOCK(&malloc_mutex);
+ MALLOC_UNLOCK;
}
-/*
- * When a program attempts "storage compaction" as mentioned in the
- * old malloc man page, it realloc's an already freed block. Usually
- * this is the last block it freed; occasionally it might be farther
- * back. We have to search all the free lists for the block in order
- * to determine its bucket: 1st we make one pass thru the lists
- * checking only the first block in each; if that fails we search
- * ``reall_srchlen'' blocks in each list for a match (the variable
- * is extern so the caller can modify it). If that fails we just copy
- * however many bytes was given to realloc() and hope it's not huge.
- */
-int reall_srchlen = 4; /* 4 should be plenty, -1 =>'s whole list */
+/* There is no need to do any locking in realloc (with an exception of
+ trying to grow in place if we are at the end of the chain).
+ If somebody calls us from a different thread with the same address,
+ we are sole anyway. */
Malloc_t
-realloc(mp, nbytes)
- Malloc_t mp;
- MEM_SIZE nbytes;
-{
+Perl_realloc(void *mp, size_t nbytes)
+{
register MEM_SIZE onb;
union overhead *ovp;
char *res;
- register int i;
- int was_alloced = 0;
+ int prev_bucket;
+ register int bucket;
+ int incr; /* 1 if does not fit, -1 if "easily" fits in a
+ smaller bucket, otherwise 0. */
char *cp = (char*)mp;
-#ifdef DEBUGGING
+#if defined(DEBUGGING) || !defined(PERL_CORE)
MEM_SIZE size = nbytes;
-#endif
-#ifdef PERL_CORE
-#ifdef HAS_64K_LIMIT
- if (nbytes > 0xffff) {
- PerlIO_printf(PerlIO_stderr(),
- "Reallocation too large: %lx\n", size);
- my_exit(1);
- }
-#endif /* HAS_64K_LIMIT */
- if (!cp)
- return malloc(nbytes);
-#ifdef DEBUGGING
if ((long)nbytes < 0)
- croak("panic: realloc");
+ croak("%s", "panic: realloc");
#endif
-#endif /* PERL_CORE */
- MUTEX_LOCK(&malloc_mutex);
+ BARK_64K_LIMIT("Reallocation",nbytes,size);
+ if (!cp)
+ return Perl_malloc(nbytes);
+
ovp = (union overhead *)((caddr_t)cp
- - sizeof (union overhead) * CHUNK_SHIFT);
- i = OV_INDEX(ovp);
- if (OV_MAGIC(ovp, i) == MAGIC) {
- was_alloced = 1;
- } else {
- /*
- * Already free, doing "compaction".
- *
- * Search for the old block of memory on the
- * free list. First, check the most common
- * case (last element free'd), then (this failing)
- * the last ``reall_srchlen'' items free'd.
- * If all lookups fail, then assume the size of
- * the memory block being realloc'd is the
- * smallest possible.
- */
- if ((i = findbucket(ovp, 1)) < 0 &&
- (i = findbucket(ovp, reall_srchlen)) < 0)
- i = 0;
- }
- onb = (1L << (i + 3)) -
-#ifdef PACK_MALLOC
- (i <= (MAX_PACKED - 3) ? 0 : M_OVERHEAD)
+ - sizeof (union overhead) * CHUNK_SHIFT);
+ bucket = OV_INDEX(ovp);
+
+#ifdef IGNORE_SMALL_BAD_FREE
+ if ((bucket >= FIRST_BUCKET_WITH_CHECK)
+ && (OV_MAGIC(ovp, bucket) != MAGIC))
+#else
+ if (OV_MAGIC(ovp, bucket) != MAGIC)
+#endif
+ {
+ static int bad_free_warn = -1;
+ if (bad_free_warn == -1) {
+ dTHX;
+ char *pbf = PerlEnv_getenv("PERL_BADFREE");
+ bad_free_warn = (pbf) ? atoi(pbf) : 1;
+ }
+ if (!bad_free_warn)
+ return Nullch;
+#ifdef RCHECK
+#ifdef PERL_CORE
+ {
+ dTHX;
+ if (!PERL_IS_ALIVE || !PL_curcop || ckWARN_d(WARN_MALLOC))
+ Perl_warner(aTHX_ WARN_MALLOC, "%srealloc() %signored",
+ (ovp->ov_rmagic == RMAGIC - 1 ? "" : "Bad "),
+ ovp->ov_rmagic == RMAGIC - 1
+ ? "of freed memory " : "");
+ }
#else
- M_OVERHEAD
+ warn("%srealloc() %signored",
+ (ovp->ov_rmagic == RMAGIC - 1 ? "" : "Bad "),
+ ovp->ov_rmagic == RMAGIC - 1 ? "of freed memory " : "");
#endif
-#ifdef TWO_POT_OPTIMIZE
- + (i >= (FIRST_BIG_TWO_POT - 3) ? PERL_PAGESIZE : 0)
+#else
+#ifdef PERL_CORE
+ {
+ dTHX;
+ if (!PERL_IS_ALIVE || !PL_curcop || ckWARN_d(WARN_MALLOC))
+ Perl_warner(aTHX_ WARN_MALLOC, "%s",
+ "Bad realloc() ignored");
+ }
+#else
+ warn("%s", "Bad realloc() ignored");
#endif
- ;
+#endif
+ return Nullch; /* sanity */
+ }
+
+ onb = BUCKET_SIZE_REAL(bucket);
/*
* avoid the copy if same size block.
- * We are not agressive with boundary cases. Note that it is
- * possible for small number of cases give false negative if
+ * We are not agressive with boundary cases. Note that it might
+ * (for a small number of cases) give false negative if
* both new size and old one are in the bucket for
- * FIRST_BIG_TWO_POT, but the new one is near the lower end.
+ * FIRST_BIG_POW2, but the new one is near the lower end.
+ *
+ * We do not try to go to 1.5 times smaller bucket so far.
*/
- if (was_alloced &&
- nbytes <= onb && (nbytes > ( (onb >> 1) - M_OVERHEAD )
-#ifdef TWO_POT_OPTIMIZE
- || (i == (FIRST_BIG_TWO_POT - 3)
- && nbytes >= LAST_SMALL_BOUND )
-#endif
- )) {
+ if (nbytes > onb) incr = 1;
+ else {
+#ifdef DO_NOT_TRY_HARDER_WHEN_SHRINKING
+ if ( /* This is a little bit pessimal if PACK_MALLOC: */
+ nbytes > ( (onb >> 1) - M_OVERHEAD )
+# ifdef TWO_POT_OPTIMIZE
+ || (bucket == FIRST_BIG_POW2 && nbytes >= LAST_SMALL_BOUND )
+# endif
+ )
+#else /* !DO_NOT_TRY_HARDER_WHEN_SHRINKING */
+ prev_bucket = ( (bucket > MAX_PACKED + 1)
+ ? bucket - BUCKETS_PER_POW2
+ : bucket - 1);
+ if (nbytes > BUCKET_SIZE_REAL(prev_bucket))
+#endif /* !DO_NOT_TRY_HARDER_WHEN_SHRINKING */
+ incr = 0;
+ else incr = -1;
+ }
+#ifdef STRESS_REALLOC
+ goto hard_way;
+#endif
+ if (incr == 0) {
+ inplace_label:
#ifdef RCHECK
/*
* Record new allocated size of block and
* bound space with magic numbers.
*/
if (OV_INDEX(ovp) <= MAX_SHORT_BUCKET) {
+ int i, nb = ovp->ov_size + 1;
+
+ if ((i = nb & 3)) {
+ i = 4 - i;
+ while (i--) {
+ ASSERT(*((char *)((caddr_t)ovp + nb - RSLOP + i)) == RMAGIC_C, "chunk's tail overwrite");
+ }
+ }
+ nb = (nb + 3) &~ 3;
+ ASSERT(*(u_int *)((caddr_t)ovp + nb - RSLOP) == RMAGIC, "chunk's tail overwrite");
/*
* Convert amount of memory requested into
* closest block size stored in hash buckets
* space used per block for accounting.
*/
nbytes += M_OVERHEAD;
- nbytes = (nbytes + 3) &~ 3;
ovp->ov_size = nbytes - 1;
+ if ((i = nbytes & 3)) {
+ i = 4 - i;
+ while (i--)
+ *((char *)((caddr_t)ovp + nbytes - RSLOP + i))
+ = RMAGIC_C;
+ }
+ nbytes = (nbytes + 3) &~ 3;
*((u_int *)((caddr_t)ovp + nbytes - RSLOP)) = RMAGIC;
}
#endif
res = cp;
- MUTEX_UNLOCK(&malloc_mutex);
- }
- else {
- MUTEX_UNLOCK(&malloc_mutex);
- if ((res = (char*)malloc(nbytes)) == NULL)
- return (NULL);
- if (cp != res) /* common optimization */
- Copy(cp, res, (MEM_SIZE)(nbytes<onb?nbytes:onb), char);
- if (was_alloced)
- free(cp);
+ DEBUG_m(PerlIO_printf(Perl_debug_log,
+ "0x%"UVxf": (%05lu) realloc %ld bytes inplace\n",
+ PTR2UV(res),(unsigned long)(PL_an++),
+ (long)size));
+ } else if (incr == 1 && (cp - M_OVERHEAD == last_op)
+ && (onb > (1 << LOG_OF_MIN_ARENA))) {
+ MEM_SIZE require, newarena = nbytes, pow;
+ int shiftr;
+
+ POW2_OPTIMIZE_ADJUST(newarena);
+ newarena = newarena + M_OVERHEAD;
+ /* newarena = (newarena + 3) &~ 3; */
+ shiftr = (newarena - 1) >> LOG_OF_MIN_ARENA;
+ pow = LOG_OF_MIN_ARENA + 1;
+ /* apart from this loop, this is O(1) */
+ while (shiftr >>= 1)
+ pow++;
+ newarena = (1 << pow) + POW2_OPTIMIZE_SURPLUS(pow * BUCKETS_PER_POW2);
+ require = newarena - onb - M_OVERHEAD;
+
+ MALLOC_LOCK;
+ if (cp - M_OVERHEAD == last_op /* We *still* are the last chunk */
+ && getpages_adjacent(require)) {
+#ifdef DEBUGGING_MSTATS
+ nmalloc[bucket]--;
+ nmalloc[pow * BUCKETS_PER_POW2]++;
+#endif
+ *(cp - M_OVERHEAD) = pow * BUCKETS_PER_POW2; /* Fill index. */
+ MALLOC_UNLOCK;
+ goto inplace_label;
+ } else {
+ MALLOC_UNLOCK;
+ goto hard_way;
+ }
+ } else {
+ hard_way:
+ DEBUG_m(PerlIO_printf(Perl_debug_log,
+ "0x%"UVxf": (%05lu) realloc %ld bytes the hard way\n",
+ PTR2UV(cp),(unsigned long)(PL_an++),
+ (long)size));
+ if ((res = (char*)Perl_malloc(nbytes)) == NULL)
+ return (NULL);
+ if (cp != res) /* common optimization */
+ Copy(cp, res, (MEM_SIZE)(nbytes<onb?nbytes:onb), char);
+ Perl_mfree(cp);
}
-
-#ifdef PERL_CORE
-#ifdef DEBUGGING
- if (debug & 128) {
- PerlIO_printf(PerlIO_stderr(), "0x%lx: (%05lu) rfree\n",(unsigned long)res,(unsigned long)(an++));
- PerlIO_printf(PerlIO_stderr(), "0x%lx: (%05lu) realloc %ld bytes\n",
- (unsigned long)res,(unsigned long)(an++),(long)size);
- }
-#endif
-#endif /* PERL_CORE */
return ((Malloc_t)res);
}
-/*
- * Search ``srchlen'' elements of each free list for a block whose
- * header starts at ``freep''. If srchlen is -1 search the whole list.
- * Return bucket number, or -1 if not found.
- */
-static int
-findbucket(freep, srchlen)
- union overhead *freep;
- int srchlen;
-{
- register union overhead *p;
- register int i, j;
-
- for (i = 0; i < NBUCKETS; i++) {
- j = 0;
- for (p = nextf[i]; p && j != srchlen; p = p->ov_next) {
- if (p == freep)
- return (i);
- j++;
- }
- }
- return (-1);
-}
-
Malloc_t
-calloc(elements, size)
- register MEM_SIZE elements;
- register MEM_SIZE size;
+Perl_calloc(register size_t elements, register size_t size)
{
long sz = elements * size;
- Malloc_t p = malloc(sz);
+ Malloc_t p = Perl_malloc(sz);
if (p) {
memset((void*)p, 0, sz);
return p;
}
+char *
+Perl_strdup(const char *s)
+{
+ MEM_SIZE l = strlen(s);
+ char *s1 = (char *)Perl_malloc(l+1);
+
+ Copy(s, s1, (MEM_SIZE)(l+1), char);
+ return s1;
+}
+
+#ifdef PERL_CORE
+int
+Perl_putenv(char *a)
+{
+ /* Sometimes system's putenv conflicts with my_setenv() - this is system
+ malloc vs Perl's free(). */
+ dTHX;
+ char *var;
+ char *val = a;
+ MEM_SIZE l;
+ char buf[80];
+
+ while (*val && *val != '=')
+ val++;
+ if (!*val)
+ return -1;
+ l = val - a;
+ if (l < sizeof(buf))
+ var = buf;
+ else
+ var = Perl_malloc(l + 1);
+ Copy(a, var, l, char);
+ var[l + 1] = 0;
+ my_setenv(var, val+1);
+ if (var != buf)
+ Perl_mfree(var);
+ return 0;
+}
+# endif
+
+MEM_SIZE
+Perl_malloced_size(void *p)
+{
+ union overhead *ovp = (union overhead *)
+ ((caddr_t)p - sizeof (union overhead) * CHUNK_SHIFT);
+ int bucket = OV_INDEX(ovp);
+#ifdef RCHECK
+ /* The caller wants to have a complete control over the chunk,
+ disable the memory checking inside the chunk. */
+ if (bucket <= MAX_SHORT_BUCKET) {
+ MEM_SIZE size = BUCKET_SIZE_REAL(bucket);
+ ovp->ov_size = size + M_OVERHEAD - 1;
+ *((u_int *)((caddr_t)ovp + size + M_OVERHEAD - RSLOP)) = RMAGIC;
+ }
+#endif
+ return BUCKET_SIZE_REAL(bucket);
+}
+
+# ifdef BUCKETS_ROOT2
+# define MIN_EVEN_REPORT 6
+# else
+# define MIN_EVEN_REPORT MIN_BUCKET
+# endif
+
+int
+Perl_get_mstats(pTHX_ perl_mstats_t *buf, int buflen, int level)
+{
#ifdef DEBUGGING_MSTATS
+ register int i, j;
+ register union overhead *p;
+ struct chunk_chain_s* nextchain;
+
+ buf->topbucket = buf->topbucket_ev = buf->topbucket_odd
+ = buf->totfree = buf->total = buf->total_chain = 0;
+
+ buf->minbucket = MIN_BUCKET;
+ MALLOC_LOCK;
+ for (i = MIN_BUCKET ; i < NBUCKETS; i++) {
+ for (j = 0, p = nextf[i]; p; p = p->ov_next, j++)
+ ;
+ if (i < buflen) {
+ buf->nfree[i] = j;
+ buf->ntotal[i] = nmalloc[i];
+ }
+ buf->totfree += j * BUCKET_SIZE_REAL(i);
+ buf->total += nmalloc[i] * BUCKET_SIZE_REAL(i);
+ if (nmalloc[i]) {
+ i % 2 ? (buf->topbucket_odd = i) : (buf->topbucket_ev = i);
+ buf->topbucket = i;
+ }
+ }
+ nextchain = chunk_chain;
+ while (nextchain) {
+ buf->total_chain += nextchain->size;
+ nextchain = nextchain->next;
+ }
+ buf->total_sbrk = goodsbrk + sbrk_slack;
+ buf->sbrks = sbrks;
+ buf->sbrk_good = sbrk_good;
+ buf->sbrk_slack = sbrk_slack;
+ buf->start_slack = start_slack;
+ buf->sbrked_remains = sbrked_remains;
+ MALLOC_UNLOCK;
+ if (level) {
+ for (i = MIN_BUCKET ; i < NBUCKETS; i++) {
+ if (i >= buflen)
+ break;
+ buf->bucket_mem_size[i] = BUCKET_SIZE(i);
+ buf->bucket_available_size[i] = BUCKET_SIZE_REAL(i);
+ }
+ }
+#endif /* defined DEBUGGING_MSTATS */
+ return 0; /* XXX unused */
+}
/*
* mstats - print out statistics about malloc
*
* frees for each size category.
*/
void
-dump_mstats(s)
- char *s;
+Perl_dump_mstats(pTHX_ char *s)
{
+#ifdef DEBUGGING_MSTATS
register int i, j;
register union overhead *p;
- int topbucket=0, totfree=0, total=0;
- u_int nfree[NBUCKETS];
+ perl_mstats_t buffer;
+ unsigned long nf[NBUCKETS];
+ unsigned long nt[NBUCKETS];
+ struct chunk_chain_s* nextchain;
+
+ buffer.nfree = nf;
+ buffer.ntotal = nt;
+ get_mstats(&buffer, NBUCKETS, 0);
- for (i=0; i < NBUCKETS; i++) {
- for (j = 0, p = nextf[i]; p; p = p->ov_next, j++)
- ;
- nfree[i] = j;
- totfree += nfree[i] * (1 << (i + 3));
- total += nmalloc[i] * (1 << (i + 3));
- if (nmalloc[i])
- topbucket = i;
- }
if (s)
- PerlIO_printf(PerlIO_stderr(), "Memory allocation statistics %s (buckets 8..%d)\n",
- s, (1 << (topbucket + 3)) );
- PerlIO_printf(PerlIO_stderr(), "%8d free:", totfree);
- for (i=0; i <= topbucket; i++) {
- PerlIO_printf(PerlIO_stderr(), (i<5 || i==7)?" %5d": (i<9)?" %3d":" %d", nfree[i]);
+ PerlIO_printf(Perl_error_log,
+ "Memory allocation statistics %s (buckets %ld(%ld)..%ld(%ld)\n",
+ s,
+ (long)BUCKET_SIZE_REAL(MIN_BUCKET),
+ (long)BUCKET_SIZE(MIN_BUCKET),
+ (long)BUCKET_SIZE_REAL(buffer.topbucket),
+ (long)BUCKET_SIZE(buffer.topbucket));
+ PerlIO_printf(Perl_error_log, "%8ld free:", buffer.totfree);
+ for (i = MIN_EVEN_REPORT; i <= buffer.topbucket; i += BUCKETS_PER_POW2) {
+ PerlIO_printf(Perl_error_log,
+ ((i < 8*BUCKETS_PER_POW2 || i == 10*BUCKETS_PER_POW2)
+ ? " %5d"
+ : ((i < 12*BUCKETS_PER_POW2) ? " %3d" : " %d")),
+ buffer.nfree[i]);
}
- PerlIO_printf(PerlIO_stderr(), "\n%8d used:", total - totfree);
- for (i=0; i <= topbucket; i++) {
- PerlIO_printf(PerlIO_stderr(), (i<5 || i==7)?" %5d": (i<9)?" %3d":" %d", nmalloc[i] - nfree[i]);
+#ifdef BUCKETS_ROOT2
+ PerlIO_printf(Perl_error_log, "\n\t ");
+ for (i = MIN_BUCKET + 1; i <= buffer.topbucket_odd; i += BUCKETS_PER_POW2) {
+ PerlIO_printf(Perl_error_log,
+ ((i < 8*BUCKETS_PER_POW2 || i == 10*BUCKETS_PER_POW2)
+ ? " %5d"
+ : ((i < 12*BUCKETS_PER_POW2) ? " %3d" : " %d")),
+ buffer.nfree[i]);
}
- PerlIO_printf(PerlIO_stderr(), "\nTotal sbrk(): %8d. Odd ends: sbrk(): %7d, malloc(): %7d bytes.\n",
- goodsbrk + sbrk_slack, sbrk_slack, start_slack);
-}
-#else
-void
-dump_mstats(s)
- char *s;
-{
+#endif
+ PerlIO_printf(Perl_error_log, "\n%8ld used:", buffer.total - buffer.totfree);
+ for (i = MIN_EVEN_REPORT; i <= buffer.topbucket; i += BUCKETS_PER_POW2) {
+ PerlIO_printf(Perl_error_log,
+ ((i < 8*BUCKETS_PER_POW2 || i == 10*BUCKETS_PER_POW2)
+ ? " %5d"
+ : ((i < 12*BUCKETS_PER_POW2) ? " %3d" : " %d")),
+ buffer.ntotal[i] - buffer.nfree[i]);
+ }
+#ifdef BUCKETS_ROOT2
+ PerlIO_printf(Perl_error_log, "\n\t ");
+ for (i = MIN_BUCKET + 1; i <= buffer.topbucket_odd; i += BUCKETS_PER_POW2) {
+ PerlIO_printf(Perl_error_log,
+ ((i < 8*BUCKETS_PER_POW2 || i == 10*BUCKETS_PER_POW2)
+ ? " %5d"
+ : ((i < 12*BUCKETS_PER_POW2) ? " %3d" : " %d")),
+ buffer.ntotal[i] - buffer.nfree[i]);
+ }
+#endif
+ PerlIO_printf(Perl_error_log, "\nTotal sbrk(): %ld/%ld:%ld. Odd ends: pad+heads+chain+tail: %ld+%ld+%ld+%ld.\n",
+ buffer.total_sbrk, buffer.sbrks, buffer.sbrk_good,
+ buffer.sbrk_slack, buffer.start_slack,
+ buffer.total_chain, buffer.sbrked_remains);
+#endif /* DEBUGGING_MSTATS */
}
-#endif
#endif /* lint */
-
#ifdef USE_PERL_SBRK
-# ifdef NeXT
+# if defined(__MACHTEN_PPC__) || defined(NeXT) || defined(__NeXT__) || defined(PURIFY)
# define PERL_SBRK_VIA_MALLOC
# endif
# ifdef PERL_SBRK_VIA_MALLOC
-# if defined(HIDEMYMALLOC) || defined(EMBEDMYMALLOC)
-# undef malloc
-# else
-# include "Error: -DPERL_SBRK_VIA_MALLOC needs -D(HIDE|EMBED)MYMALLOC"
-# endif
/* it may seem schizophrenic to use perl's malloc and let it call system */
/* malloc, the reason for that is only the 3.2 version of the OS that had */
/* frequent core dumps within nxzonefreenolock. This sbrk routine put an */
/* end to the cores */
-# define SYSTEM_ALLOC(a) malloc(a)
+# ifndef SYSTEM_ALLOC
+# define SYSTEM_ALLOC(a) malloc(a)
+# endif
+# ifndef SYSTEM_ALLOC_ALIGNMENT
+# define SYSTEM_ALLOC_ALIGNMENT MEM_ALIGNBYTES
+# endif
# endif /* PERL_SBRK_VIA_MALLOC */
# define PERLSBRK_32_K (1<<15)
# define PERLSBRK_64_K (1<<16)
-char *
-Perl_sbrk(size)
-int size;
+Malloc_t
+Perl_sbrk(int size)
{
IV got;
int small, reqsize;
if (size >= PERLSBRK_32_K) {
small = 0;
} else {
-#ifndef PERL_CORE
- reqsize = size;
-#endif
size = PERLSBRK_64_K;
small = 1;
}
+# if NEEDED_ALIGNMENT > SYSTEM_ALLOC_ALIGNMENT
+ size += NEEDED_ALIGNMENT - SYSTEM_ALLOC_ALIGNMENT;
+# endif
got = (IV)SYSTEM_ALLOC(size);
-#ifdef PACK_MALLOC
- got = (got + 0x7ff) & ~0x7ff;
-#endif
+# if NEEDED_ALIGNMENT > SYSTEM_ALLOC_ALIGNMENT
+ got = (got + NEEDED_ALIGNMENT - 1) & ~(NEEDED_ALIGNMENT - 1);
+# endif
if (small) {
/* Chunk is small, register the rest for future allocs. */
Perl_sbrk_oldchunk = got + reqsize;
}
}
-#ifdef PERL_CORE
- DEBUG_m(PerlIO_printf(PerlIO_stderr(), "sbrk malloc size %ld (reqsize %ld), left size %ld, give addr 0x%lx\n",
- size, reqsize, Perl_sbrk_oldsize, got));
-#endif
+ DEBUG_m(PerlIO_printf(Perl_debug_log, "sbrk malloc size %ld (reqsize %ld), left size %ld, give addr 0x%"UVxf"\n",
+ size, reqsize, Perl_sbrk_oldsize, PTR2UV(got)));
return (void *)got;
}
https://perl5.git.perl.org / perl5.git / blobdiff