* number of different sizes, and keeps free lists of each size. Blocks that
* don't exactly fit are passed up to the next larger size. In this
* implementation, the available sizes are 2^n-4 (or 2^n-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.
*/
#define u_int unsigned int
#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
+#endif
+
+
/*
+ * The description below is applicable if PACK_MALLOC is not defined.
+ *
* The overhead on a block is at least 4 bytes. When free, this space
* contains a pointer to the next free block, and the bottom two bits must
* be zero. When in use, the first byte is set to MAGIC, and the second
#define RSLOP 0
#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.
+ *
+ * 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).
+ *
+ * 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.
+ *
+ * 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) ((int)x & ~TWOK_MASK)
+# define TWOK_SHIFT(x) ((int)x & TWOK_MASK)
+# define OV_INDEXp(block) ((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)))
+# 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. */
+};
+
+# ifdef DEBUGGING_MSTATS
+static u_int sbrk_slack;
+static u_int start_slack;
+# endif
+
+#else /* !PACK_MALLOC */
+
+# define OV_MAGIC(block,bucket) (block)->ov_magic
+# define OV_INDEX(block) (block)->ov_index
+# define CHUNK_SHIFT 1
+#endif /* !PACK_MALLOC */
+
+# define M_OVERHEAD (sizeof(union overhead) + RSLOP)
+
/*
* nextf[i] is the pointer to the next free block of size 2^(i+3). The
* smallest allocatable block is 8 bytes. The overhead information
*/
#define NBUCKETS 30
static union overhead *nextf[NBUCKETS];
+
+#ifdef USE_PERL_SBRK
+#define sbrk(a) Perl_sbrk(a)
+char * Perl_sbrk _((int size));
+#else
extern char *sbrk();
+#endif
#ifdef DEBUGGING_MSTATS
/*
* which satisfies request. Account for
* space used per block for accounting.
*/
- nbytes += sizeof (union overhead) + RSLOP;
- nbytes = (nbytes + 3) &~ 3;
+#ifdef PACK_MALLOC
+ if (nbytes > MAX_2_POT_ALGO) {
+#endif
+ nbytes += M_OVERHEAD;
+ nbytes = (nbytes + 3) &~ 3;
+#ifdef PACK_MALLOC
+ } else if (nbytes == 0) {
+ nbytes = 1;
+ }
+#endif
shiftr = (nbytes - 1) >> 2;
/* apart from this loop, this is O(1) */
while (shiftr >>= 1)
}
#ifdef safemalloc
- DEBUG_m(fprintf(stderr,"0x%lx: (%05d) malloc %ld bytes\n",
+ DEBUG_m(fprintf(Perl_debug_log,"0x%lx: (%05d) malloc %ld bytes\n",
(unsigned long)(p+1),an++,(long)size));
#endif /* safemalloc */
(unsigned long)*((int*)p),(unsigned long)p);
#endif
nextf[bucket] = p->ov_next;
- p->ov_magic = MAGIC;
- p->ov_index= bucket;
+ OV_MAGIC(p, bucket) = MAGIC;
+#ifndef PACK_MALLOC
+ OV_INDEX(p) = bucket;
+#endif
#ifdef DEBUGGING_MSTATS
nmalloc[bucket]++;
#endif
p->ov_rmagic = RMAGIC;
*((u_int *)((caddr_t)p + nbytes - RSLOP)) = RMAGIC;
#endif
- return ((Malloc_t)(p + 1));
+ return ((Malloc_t)(p + CHUNK_SHIFT));
}
/*
register int rnu; /* 2^rnu bytes will be requested */
register int nblks; /* become nblks blocks of the desired size */
register MEM_SIZE siz;
+ int slack = 0;
if (nextf[bucket])
return;
*/
#ifndef atarist /* on the atari we dont have to worry about this */
op = (union overhead *)sbrk(0);
-#ifndef I286
+# ifndef I286
+# ifdef PACK_MALLOC
+ if ((int)op & 0x7ff)
+ (void)sbrk(slack = 2048 - ((int)op & 0x7ff));
+# else
if ((int)op & 0x3ff)
- (void)sbrk(1024 - ((int)op & 0x3ff));
-#else
+ (void)sbrk(slack = 1024 - ((int)op & 0x3ff));
+# endif
+# if defined(DEBUGGING_MSTATS) && defined(PACK_MALLOC)
+ sbrk_slack += slack;
+# endif
+# else
/* The sbrk(0) call on the I286 always returns the next segment */
-#endif
+# endif
#endif /* atarist */
#if !(defined(I286) || defined(atarist))
rnu = (bucket <= 11) ? 14 : bucket + 3;
#endif
nblks = 1 << (rnu - (bucket + 3)); /* how many blocks to get */
- if (rnu < bucket)
- rnu = bucket;
+ /* if (rnu < bucket)
+ rnu = bucket; Why anyone needs this? */
op = (union overhead *)sbrk(1L << rnu);
/* no more room! */
if ((int)op == -1)
* and deduct from block count to reflect.
*/
#ifndef I286
+# ifdef PACK_MALLOC
+ if ((int)op & 0x7ff)
+ croak("panic: Off-page sbrk");
+# endif
if ((int)op & 7) {
op = (union overhead *)(((MEM_SIZE)op + 8) &~ 7);
nblks--;
* Add new memory allocated to that on
* free list for this hash bucket.
*/
- nextf[bucket] = op;
siz = 1 << (bucket + 3);
+#ifdef PACK_MALLOC
+ *(u_char*)op = bucket; /* Fill index. */
+ if (bucket <= MAX_PACKED - 3) {
+ op = (union overhead *) ((char*)op + blk_shift[bucket]);
+ nblks = n_blks[bucket];
+# ifdef DEBUGGING_MSTATS
+ start_slack += blk_shift[bucket];
+# endif
+ } else if (bucket <= 11 - 1 - 3) {
+ op = (union overhead *) ((char*)op + blk_shift[bucket]);
+ /* nblks = n_blks[bucket]; */
+ siz -= sizeof(union overhead);
+ } else op++; /* One chunk per block. */
+#endif /* !PACK_MALLOC */
+ nextf[bucket] = op;
while (--nblks > 0) {
op->ov_next = (union overhead *)((caddr_t)op + siz);
op = (union overhead *)((caddr_t)op + siz);
}
+#if defined(USE_PERL_SBRK) || defined(OS2)
+ /* all real sbrks return zeroe-d memory, perl's sbrk doesn't guarantee this */
+ op->ov_next = (union overhead *)NULL;
+#endif
+#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;
+ }
+#endif /* !PACK_MALLOC */
}
Free_t
register MEM_SIZE size;
register union overhead *op;
char *cp = (char*)mp;
+#ifdef PACK_MALLOC
+ u_char bucket;
+#endif
#ifdef safemalloc
- DEBUG_m(fprintf(stderr,"0x%lx: (%05d) free\n",(unsigned long)cp,an++));
+ DEBUG_m(fprintf(Perl_debug_log,"0x%lx: (%05d) free\n",(unsigned long)cp,an++));
#endif /* safemalloc */
- if (cp == NULL)
- return;
- op = (union overhead *)((caddr_t)cp - sizeof (union overhead));
+ if (cp == NULL)
+ return;
+ op = (union overhead *)((caddr_t)cp
+ - sizeof (union overhead) * CHUNK_SHIFT);
+#ifdef PACK_MALLOC
+ bucket = OV_INDEX(op);
+#endif
#ifdef debug
- ASSERT(op->ov_magic == MAGIC); /* make sure it was in use */
+ ASSERT(OV_MAGIC(op, bucket) == MAGIC); /* make sure it was in use */
#else
- if (op->ov_magic != MAGIC) {
+ if (OV_MAGIC(op, bucket) != MAGIC) {
+ static bad_free_warn = -1;
+ if (bad_free_warn == -1) {
+ char *pbf = getenv("PERL_BADFREE");
+ bad_free_warn = (pbf) ? atoi(pbf) : 1;
+ }
+ if (!bad_free_warn)
+ return;
#ifdef RCHECK
warn("%s free() ignored",
op->ov_rmagic == RMAGIC - 1 ? "Duplicate" : "Bad");
#endif
#ifdef RCHECK
ASSERT(op->ov_rmagic == RMAGIC);
- if (op->ov_index <= 13)
+ if (OV_INDEX(op) <= 13)
ASSERT(*(u_int *)((caddr_t)op + op->ov_size + 1 - RSLOP) == RMAGIC);
op->ov_rmagic = RMAGIC - 1;
#endif
- ASSERT(op->ov_index < NBUCKETS);
- size = op->ov_index;
+ ASSERT(OV_INDEX(op) < NBUCKETS);
+ size = OV_INDEX(op);
op->ov_next = nextf[size];
nextf[size] = op;
#ifdef DEBUGGING_MSTATS
#endif
#endif /* safemalloc */
- op = (union overhead *)((caddr_t)cp - sizeof (union overhead));
- if (op->ov_magic == MAGIC) {
+ op = (union overhead *)((caddr_t)cp
+ - sizeof (union overhead) * CHUNK_SHIFT);
+ i = OV_INDEX(op);
+ if (OV_MAGIC(op, i) == MAGIC) {
was_alloced++;
- i = op->ov_index;
} else {
/*
* Already free, doing "compaction".
(i = findbucket(op, reall_srchlen)) < 0)
i = 0;
}
- onb = (1L << (i + 3)) - sizeof (*op) - RSLOP;
+ onb = (1L << (i + 3)) -
+#ifdef PACK_MALLOC
+ (i <= (MAX_PACKED - 3) ? 0 : M_OVERHEAD)
+#else
+ M_OVERHEAD
+#endif
+ ;
/* avoid the copy if same size block */
if (was_alloced &&
- nbytes <= onb && nbytes > (onb >> 1) - sizeof(*op) - RSLOP) {
+ nbytes <= onb && nbytes > (onb >> 1) - M_OVERHEAD) {
#ifdef RCHECK
/*
* Record new allocated size of block and
* bound space with magic numbers.
*/
- if (op->ov_index <= 13) {
+ if (OV_INDEX(op) <= 13) {
/*
* Convert amount of memory requested into
* closest block size stored in hash buckets
* which satisfies request. Account for
* space used per block for accounting.
*/
- nbytes += sizeof (union overhead) + RSLOP;
+ nbytes += M_OVERHEAD;
nbytes = (nbytes + 3) &~ 3;
op->ov_size = nbytes - 1;
*((u_int *)((caddr_t)op + nbytes - RSLOP)) = RMAGIC;
return (-1);
}
+Malloc_t
+calloc(elements, size)
+ register MEM_SIZE elements;
+ register MEM_SIZE size;
+{
+ long sz = elements * size;
+ Malloc_t p = malloc(sz);
+
+ if (p) {
+ memset((void*)p, 0, sz);
+ }
+ return p;
+}
+
#ifdef DEBUGGING_MSTATS
/*
* mstats - print out statistics about malloc
fprintf(stderr, (i<5)?" %5d":" %3d", nmalloc[i]);
}
fprintf(stderr, "\n");
+#ifdef PACK_MALLOC
+ if (sbrk_slack || start_slack) {
+ fprintf(stderr, "Odd ends: %7d bytes from sbrk(), %7d from malloc.\n",
+ sbrk_slack, start_slack);
+ }
+#endif
}
#else
void
}
#endif
#endif /* lint */
+
+
+#ifdef USE_PERL_SBRK
+
+#ifdef NeXT
+#ifdef HIDEMYMALLOC
+#undef malloc
+#else
+#include "Error: -DUSE_PERL_SBRK on the NeXT requires -DHIDEMYMALLOC"
+#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)
+
+#else
+
+/* OS/2 comes to mind ... */
+
+#endif
+
+
+static IV Perl_sbrk_oldchunk;
+static long Perl_sbrk_oldsize;
+
+#define PERLSBRK_32_K (1<<15)
+#define PERLSBRK_64_K (1<<16)
+
+char *
+Perl_sbrk(size)
+int size;
+{
+ IV got;
+ int small, reqsize;
+
+ if (!size) return 0;
+#ifdef safemalloc
+ reqsize = size; /* just for the DEBUG_m statement */
+#endif
+ if (size <= Perl_sbrk_oldsize) {
+ got = Perl_sbrk_oldchunk;
+ Perl_sbrk_oldchunk += size;
+ Perl_sbrk_oldsize -= size;
+ } else {
+ if (size >= PERLSBRK_32_K) {
+ small = 0;
+ } else {
+#ifndef safemalloc
+ reqsize = size;
+#endif
+ size = PERLSBRK_64_K;
+ small = 1;
+ }
+ got = (IV)SYSTEM_ALLOC(size);
+ if (small) {
+ /* Chunk is small, register the rest for future allocs. */
+ Perl_sbrk_oldchunk = got + reqsize;
+ Perl_sbrk_oldsize = size - reqsize;
+ }
+ }
+
+#ifdef safemalloc
+ DEBUG_m(fprintf(stderr,"sbrk malloc size %ld (reqsize %ld), left size %ld, give addr 0x%lx\n",
+ size, reqsize, Perl_sbrk_oldsize, got));
+#endif
+
+ return (void *)got;
+}
+
+#endif /* ! defined USE_PERL_SBRK */
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