*/
/*
- Here are some notes on configuring Perl's malloc.
+ 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
# 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
# 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
+
+ # 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
#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))
+#if !(defined(I286) || defined(atarist) || defined(__MINT__))
/* take 2k unless the block is bigger than that */
# define LOG_OF_MIN_ARENA 11
#else
* 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 1996-98.
+ *
+ * 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.
+ *
*/
#ifdef PERL_CORE
# define PerlIO_stderr() stderr
# endif
# ifndef croak /* make depend */
-# define croak(mess, arg) warn((mess), (arg)); exit(1);
+# define croak(mess, arg) (warn((mess), (arg)), exit(1))
# endif
# ifndef warn
-# define warn(mess, arg) fprintf(stderr, (mess), (arg));
+# define warn(mess, arg) fprintf(stderr, (mess), (arg))
# endif
# ifdef DEBUG_m
# undef DEBUG_m
# 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 (PL_debug & 128) a
#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 of 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_short unsigned short
/* 286 and atarist like big chunks, which gives too much overhead. */
-#if (defined(RCHECK) || defined(I286) || defined(atarist)) && defined(PACK_MALLOC)
+#if (defined(RCHECK) || defined(I286) || defined(atarist) || defined(__MINT__)) && defined(PACK_MALLOC)
# undef PACK_MALLOC
#endif
#endif
static void morecore _((int bucket));
static int findbucket _((union overhead *freep, int srchlen));
+static void add_to_chain(void *p, MEM_SIZE size, MEM_SIZE chip);
#define MAGIC 0xff /* magic # on accounting info */
#define RMAGIC 0x55555555 /* magic # on range info */
# 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 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 Malloc_t emergency_sbrk(MEM_SIZE size);
static Malloc_t
-emergency_sbrk(size)
- MEM_SIZE size;
+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: */
- MUTEX_UNLOCK(&PL_malloc_mutex);
+ 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 {
dTHR;
/* First offense, give a possibility to recover by dieing. */
/* No malloc involved here: */
GV **gvp = (GV**)hv_fetch(PL_defstash, "^M", 2, 0);
SV *sv;
char *pv;
-
+ 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<<LOG_OF_MIN_ARENA) - 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_bigint)(pv - M_OVERHEAD)) & ((1<<LOG_OF_MIN_ARENA) - 1)) {
+ if (((UV)(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);
- MUTEX_UNLOCK(&PL_malloc_mutex);
- croak("Out of memory during request for %i bytes", size);
- }
- 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);
}
#else /* !(defined(PERL_EMERGENCY_SBRK) && defined(PERL_CORE)) */
static u_int goodsbrk;
#ifdef DEBUGGING
+#undef ASSERT
#define ASSERT(p,diag) if (!(p)) botch(diag,STRINGIFY(p)); else
static void
botch(char *diag, char *s)
#endif
Malloc_t
-malloc(register size_t nbytes)
+Perl_malloc(register size_t nbytes)
{
register union overhead *p;
register int bucket;
croak("%s", "panic: malloc");
#endif
- MUTEX_LOCK(&PL_malloc_mutex);
+ MALLOC_LOCK;
/*
* Convert amount of memory requested into
* closest block size stored in hash buckets
if (nextf[bucket] == NULL)
morecore(bucket);
if ((p = nextf[bucket]) == NULL) {
- MUTEX_UNLOCK(&PL_malloc_mutex);
+ MALLOC_UNLOCK;
#ifdef PERL_CORE
if (!PL_nomemok) {
PerlIO_puts(PerlIO_stderr(),"Out of memory!\n");
*((u_int *)((caddr_t)p + nbytes - RSLOP)) = RMAGIC;
}
#endif
- MUTEX_UNLOCK(&PL_malloc_mutex);
+ MALLOC_UNLOCK;
return ((Malloc_t)(p + CHUNK_SHIFT));
}
/* 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;
/* Second, check alignment. */
slack = 0;
-#ifndef atarist /* on the atari we dont have to worry about this */
+#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 */
-
- /* CHUNK_SHIFT is 1 for PACK_MALLOC, 0 otherwise. */
- if ((UV)cp & (0x7FF >> CHUNK_SHIFT)) { /* Not aligned. */
- slack = (0x800 >> CHUNK_SHIFT)
- - ((UV)cp & (0x7FF >> CHUNK_SHIFT));
+ /* WANTED_ALIGNMENT may be more than NEEDED_ALIGNMENT, but this may
+ improve performance of memory access. */
+ if ((UV)cp & (WANTED_ALIGNMENT - 1)) { /* Not aligned. */
+ slack = WANTED_ALIGNMENT - ((UV)cp & (WANTED_ALIGNMENT - 1));
add += slack;
}
# endif
-#endif /* atarist */
+#endif /* !atarist && !MINT */
if (add) {
DEBUG_m(PerlIO_printf(Perl_debug_log,
"failed to fix bad sbrk()\n"));
#ifdef PACK_MALLOC
if (slack) {
- MUTEX_UNLOCK(&PL_malloc_mutex);
- croak("%s", "panic: Off-page sbrk");
+ MALLOC_UNLOCK;
+ fatalcroak("panic: Off-page sbrk\n");
}
#endif
if (sbrked_remains) {
* and deduct from block count to reflect.
*/
+# if NEEDED_ALIGNMENT > MEM_ALIGNBYTES
+ if ((UV)ovp & (NEEDED_ALIGNMENT - 1))
+ fatalcroak("Misalignment of sbrk()\n");
+ else
+# endif
#ifndef I286 /* Again, this should always be ok on an 80286 */
- if ((UV)ovp & 7) {
- ovp = (union overhead *)(((UV)ovp + 8) & ~7);
+ if ((UV)ovp & (MEM_ALIGNBYTES - 1)) {
DEBUG_m(PerlIO_printf(Perl_debug_log,
"fixing sbrk(): %d bytes off machine alignement\n",
- (int)((UV)ovp & 7)));
+ (int)((UV)ovp & (MEM_ALIGNBYTES - 1))));
+ ovp = (union overhead *)(((UV)ovp + MEM_ALIGNBYTES) &
+ (MEM_ALIGNBYTES - 1));
(*nblksp)--;
# if defined(DEBUGGING_MSTATS)
/* This is only approx. if TWO_POT_OPTIMIZE: */
- sbrk_slack += (1 << bucket);
+ sbrk_slack += (1 << (bucket >> BUCKET_POW2_SHIFT));
# endif
}
#endif
+ ; /* Finish `else' */
sbrked_remains = require - needed;
+ last_op = cp;
}
last_sbrk_top = cp + require;
- last_op = (char*) cp;
#ifdef DEBUGGING_MSTATS
goodsbrk += require;
#endif
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),
if (nextf[bucket])
return;
if (bucket == sizeof(MEM_SIZE)*8*BUCKETS_PER_POW2) {
- MUTEX_UNLOCK(&PL_malloc_mutex);
+ MALLOC_UNLOCK;
croak("%s", "Out of memory during ridiculously large request");
}
if (bucket > max_bucket)
}
Free_t
-free(void *mp)
+Perl_mfree(void *mp)
{
register MEM_SIZE size;
register union overhead *ovp;
#endif
return; /* sanity */
}
- MUTEX_LOCK(&PL_malloc_mutex);
+ MALLOC_LOCK;
#ifdef RCHECK
ASSERT(ovp->ov_rmagic == RMAGIC, "chunk's head overwrite");
if (OV_INDEX(ovp) <= MAX_SHORT_BUCKET) {
size = OV_INDEX(ovp);
ovp->ov_next = nextf[size];
nextf[size] = ovp;
- MUTEX_UNLOCK(&PL_malloc_mutex);
+ MALLOC_UNLOCK;
}
/*
* 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 */
+#define reall_srchlen 4 /* 4 should be plenty, -1 =>'s whole list */
Malloc_t
-realloc(void *mp, size_t nbytes)
+Perl_realloc(void *mp, size_t nbytes)
{
register MEM_SIZE onb;
union overhead *ovp;
BARK_64K_LIMIT("Reallocation",nbytes,size);
if (!cp)
- return malloc(nbytes);
+ return Perl_malloc(nbytes);
- MUTEX_LOCK(&PL_malloc_mutex);
+ MALLOC_LOCK;
ovp = (union overhead *)((caddr_t)cp
- sizeof (union overhead) * CHUNK_SHIFT);
bucket = OV_INDEX(ovp);
}
#endif
res = cp;
- MUTEX_UNLOCK(&PL_malloc_mutex);
+ MALLOC_UNLOCK;
+ DEBUG_m(PerlIO_printf(Perl_debug_log,
+ "0x%lx: (%05lu) realloc %ld bytes inplace\n",
+ (unsigned long)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;
goto hard_way;
} else {
hard_way:
- MUTEX_UNLOCK(&PL_malloc_mutex);
- if ((res = (char*)malloc(nbytes)) == NULL)
+ MALLOC_UNLOCK;
+ DEBUG_m(PerlIO_printf(Perl_debug_log,
+ "0x%lx: (%05lu) realloc %ld bytes the hard way\n",
+ (unsigned long)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);
if (was_alloced)
- free(cp);
+ Perl_mfree(cp);
}
-
- DEBUG_m(PerlIO_printf(Perl_debug_log, "0x%lu: (%05lu) rfree\n",
- (unsigned long)res,(unsigned long)(PL_an++)));
- DEBUG_m(PerlIO_printf(Perl_debug_log,
- "0x%lx: (%05lu) realloc %ld bytes\n",
- (unsigned long)res,(unsigned long)(PL_an++),
- (long)size));
return ((Malloc_t)res);
}
}
Malloc_t
-calloc(register size_t elements, register size_t 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);
#ifdef USE_PERL_SBRK
-# ifdef NeXT
-# define PERL_SBRK_VIA_MALLOC
-# endif
-
-# ifdef __MACHTEN_PPC__
+# if defined(__MACHTEN_PPC__) || defined(__NeXT__)
# define PERL_SBRK_VIA_MALLOC
/*
* MachTen's malloc() returns a buffer aligned on a two-byte boundary.
*
* 980701 Dominic Dunlop <domo@computer.org>
*/
-# define SYSTEM_ALLOC(a) ((void *)(((unsigned)malloc((a)+6)+6)&~7))
+# define SYSTEM_ALLOC_ALIGNMENT 2
# endif
# ifdef PERL_SBRK_VIA_MALLOC
-# if defined(HIDEMYMALLOC) || defined(EMBEDMYMALLOC)
-# undef malloc /* Expose names that */
-# undef calloc /* HIDEMYMALLOC hides */
-# undef realloc
-# undef free
-# 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 */
# 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_64_K (1<<16)
Malloc_t
-Perl_sbrk(size)
-int size;
+Perl_sbrk(int size)
{
IV got;
int small, reqsize;
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;
projects / p5sagit/p5-mst-13.2.git / blobdiff