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-rw-r--r--xc/util/patch/malloc.c469
1 files changed, 469 insertions, 0 deletions
diff --git a/xc/util/patch/malloc.c b/xc/util/patch/malloc.c
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+++ b/xc/util/patch/malloc.c
@@ -0,0 +1,469 @@
+/*
+ * @(#)nmalloc.c 1 (Caltech) 2/21/82
+ *
+ * U of M Modified: 20 Jun 1983 ACT: strange hacks for Emacs
+ *
+ * Nov 1983, Mike@BRL, Added support for 4.1C/4.2 BSD.
+ *
+ * This is a very fast storage allocator. It allocates blocks of a small
+ * 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 -16) bytes long.
+ * This is designed for use in a program that uses vast quantities of
+ * memory, but bombs when it runs out. To make it a little better, it
+ * warns the user when he starts to get near the end.
+ *
+ * June 84, ACT: modified rcheck code to check the range given to malloc,
+ * rather than the range determined by the 2-power used.
+ *
+ * Jan 85, RMS: calls malloc_warning to issue warning on nearly full.
+ * No longer Emacs-specific; can serve as all-purpose malloc for GNU.
+ * You should call malloc_init to reinitialize after loading dumped Emacs.
+ * Call malloc_stats to get info on memory stats if MSTATS turned on.
+ * realloc knows how to return same block given, just changing its size,
+ * if the power of 2 is correct.
+ */
+
+/*
+ * 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 will
+ * go in the first int of the block, and the returned pointer will point
+ * to the second.
+ *
+#ifdef MSTATS
+ * nmalloc[i] is the difference between the number of mallocs and frees
+ * for a given block size.
+#endif
+ */
+
+#define ISALLOC ((char) 0xf7) /* magic byte that implies allocation */
+#define ISFREE ((char) 0x54) /* magic byte that implies free block */
+ /* this is for error checking only */
+
+extern char etext;
+
+/* end of the program; can be changed by calling init_malloc */
+static char *endofpure = &etext;
+
+#ifdef MSTATS
+static int nmalloc[30];
+static int nmal, nfre;
+#endif /* MSTATS */
+
+/* If range checking is not turned on, all we have is a flag indicating
+ whether memory is allocated, an index in nextf[], and a size field; to
+ realloc() memory we copy either size bytes or 1<<(index+3) bytes depending
+ on whether the former can hold the exact size (given the value of
+ 'index'). If range checking is on, we always need to know how much space
+ is allocated, so the 'size' field is never used. */
+
+struct mhead {
+ char mh_alloc; /* ISALLOC or ISFREE */
+ char mh_index; /* index in nextf[] */
+/* Remainder are valid only when block is allocated */
+ unsigned short mh_size; /* size, if < 0x10000 */
+#ifdef rcheck
+ unsigned mh_nbytes; /* number of bytes allocated */
+ int mh_magic4; /* should be == MAGIC4 */
+#endif /* rcheck */
+ };
+
+/* Access free-list pointer of a block.
+ It is stored at block + 4.
+ This is not a field in the mhead structure
+ because we want sizeof (struct mhead)
+ to describe the overhead for when the block is in use,
+ and we do not want the free-list pointer to count in that. */
+
+#define CHAIN(a) \
+ (*(struct mhead **) (sizeof (char *) + (char *) (a)))
+
+#ifdef rcheck
+
+/* To implement range checking, we write magic values in at the beginning and
+ end of each allocated block, and make sure they are undisturbed whenever a
+ free or a realloc occurs. */
+/* Written in each of the 4 bytes following the block's real space */
+#define MAGIC1 0x55
+/* Written in the 4 bytes before the block's real space */
+#define MAGIC4 0x55555555
+#define ASSERT(p) if (!(p)) botch("p"); else
+static
+botch(s)
+ char *s;
+{
+
+ printf("assertion botched: %s\n", s);
+ abort();
+}
+#define EXTRA 4 /* 4 bytes extra for MAGIC1s */
+#else
+#define ASSERT(p)
+#define EXTRA 0
+#endif /* rcheck */
+
+/* nextf[i] is free list of blocks of size 2**(i + 3) */
+
+static struct mhead *nextf[30];
+
+#ifdef M_WARN
+/* Number of bytes of writable memory we can expect to be able to get */
+static int lim_data;
+/* Level number of warnings already issued.
+ 0 -- no warnings issued.
+ 1 -- 75% warning already issued.
+ 2 -- 85% warning already issued.
+*/
+static int warnlevel;
+#endif /* M_WARN */
+
+/* nonzero once initial bunch of free blocks made */
+static int gotpool;
+
+/* Cause reinitialization based on job parameters;
+ also declare where the end of pure storage is. */
+malloc_init (end)
+ char *end; {
+ endofpure = end;
+#ifdef M_WARN
+ lim_data = 0;
+ warnlevel = 0;
+#endif /* M_WARN */
+ }
+
+static
+morecore (nu) /* ask system for more memory */
+ register int nu; { /* size index to get more of */
+ char *sbrk ();
+ register char *cp;
+ register int nblks;
+ register int siz;
+
+#ifdef M_WARN
+#ifndef BSD42
+#ifdef USG
+ extern long ulimit ();
+ if (lim_data == 0) /* find out how much we can get */
+ lim_data = ulimit (3, 0) - TEXT_START;
+#else /*HMS: was endif */
+ if (lim_data == 0) /* find out how much we can get */
+ lim_data = vlimit (LIM_DATA, -1);
+#endif /* USG */ /HMS:* was not here */
+#else
+ if (lim_data == 0) {
+ struct rlimit XXrlimit;
+
+ getrlimit (RLIMIT_DATA, &XXrlimit);
+ lim_data = XXrlimit.rlim_cur;} /* soft limit */
+#endif /* BSD42 */
+#endif /* M_WARN */
+
+ /* On initial startup, get two blocks of each size up to 1k bytes */
+ if (!gotpool)
+ getpool (), getpool (), gotpool = 1;
+
+ /* Find current end of memory and issue warning if getting near max */
+
+ cp = sbrk (0);
+ siz = cp - endofpure;
+#ifdef M_WARN
+ switch (warnlevel) {
+ case 0:
+ if (siz > (lim_data / 4) * 3) {
+ warnlevel++;
+ malloc_warning ("Warning: past 75% of memory limit");}
+ break;
+ case 1:
+ if (siz > (lim_data / 20) * 17) {
+ warnlevel++;
+ malloc_warning ("Warning: past 85% of memory limit");}
+ break;
+ case 2:
+ if (siz > (lim_data / 20) * 19) {
+ warnlevel++;
+ malloc_warning ("Warning: past 95% of memory limit");}
+ break;}
+#endif /* M_WARN */
+
+ if ((int) cp & 0x3ff) /* land on 1K boundaries */
+ sbrk (1024 - ((int) cp & 0x3ff));
+
+ /* Take at least 2k, and figure out how many blocks of the desired size we're about to get */
+ nblks = 1;
+ if ((siz = nu) < 8)
+ nblks = 1 << ((siz = 8) - nu);
+
+ if ((cp = sbrk (1 << (siz + 3))) == (char *) -1)
+ return; /* no more room! */
+ if ((int) cp & 7) { /* shouldn't happen, but just in case */
+ cp = (char *) (((int) cp + 8) & ~7);
+ nblks--;}
+
+ /* save new header and link the nblks blocks together */
+ nextf[nu] = (struct mhead *) cp;
+ siz = 1 << (nu + 3);
+ while (1) {
+ ((struct mhead *) cp) -> mh_alloc = ISFREE;
+ ((struct mhead *) cp) -> mh_index = nu;
+ if (--nblks <= 0) break;
+ CHAIN ((struct mhead *) cp) = (struct mhead *) (cp + siz);
+ cp += siz;}
+#if 0
+ CHAIN ((struct mhead *) cp) = 0; /* since sbrk() returns cleared core, this is already set */
+#endif
+ }
+
+static
+getpool () {
+ register int nu;
+ register char *cp = sbrk (0);
+
+ if ((int) cp & 0x3ff) /* land on 1K boundaries */
+ sbrk (1024 - ((int) cp & 0x3ff));
+
+ /* Get 2k of storage */
+
+ cp = sbrk (04000);
+ if (cp == (char *) -1)
+ return;
+
+ /* Divide it into an initial 8-word block
+ plus one block of size 2**nu for nu = 3 ... 10. */
+
+ CHAIN (cp) = nextf[0];
+ nextf[0] = (struct mhead *) cp;
+ ((struct mhead *) cp) -> mh_alloc = ISFREE;
+ ((struct mhead *) cp) -> mh_index = 0;
+ cp += 8;
+
+ for (nu = 0; nu < 7; nu++) {
+ CHAIN (cp) = nextf[nu];
+ nextf[nu] = (struct mhead *) cp;
+ ((struct mhead *) cp) -> mh_alloc = ISFREE;
+ ((struct mhead *) cp) -> mh_index = nu;
+ cp += 8 << nu;}}
+
+char *
+malloc (n) /* get a block */
+ unsigned n; {
+ register struct mhead *p;
+ register unsigned int nbytes;
+ register int nunits = 0;
+
+ /* Figure out how many bytes are required, rounding up to the nearest
+ multiple of 4, then figure out which nextf[] area to use */
+ nbytes = (n + sizeof *p + EXTRA + 3) & ~3;
+ {
+ register unsigned int shiftr = (nbytes - 1) >> 2;
+
+ while (shiftr >>= 1)
+ nunits++;
+ }
+
+ /* If there are no blocks of the appropriate size, go get some */
+ /* COULD SPLIT UP A LARGER BLOCK HERE ... ACT */
+ if (nextf[nunits] == 0)
+ morecore (nunits);
+
+ /* Get one block off the list, and set the new list head */
+ if ((p = nextf[nunits]) == 0)
+ return 0;
+ nextf[nunits] = CHAIN (p);
+
+ /* Check for free block clobbered */
+ /* If not for this check, we would gobble a clobbered free chain ptr */
+ /* and bomb out on the NEXT allocate of this size block */
+ if (p -> mh_alloc != ISFREE || p -> mh_index != nunits)
+#ifdef rcheck
+ botch ("block on free list clobbered");
+#else
+ abort ();
+#endif /* rcheck */
+
+ /* Fill in the info, and if range checking, set up the magic numbers */
+ p -> mh_alloc = ISALLOC;
+#ifdef rcheck
+ p -> mh_nbytes = n;
+ p -> mh_magic4 = MAGIC4;
+ {
+ register char *m = (char *) (p + 1) + n;
+
+ *m++ = MAGIC1, *m++ = MAGIC1, *m++ = MAGIC1, *m = MAGIC1;
+ }
+#else
+ p -> mh_size = n;
+#endif /* rcheck */
+#ifdef MSTATS
+ nmalloc[nunits]++;
+ nmal++;
+#endif /* MSTATS */
+ return (char *) (p + 1);}
+
+free (mem)
+ char *mem; {
+ register struct mhead *p;
+ {
+ register char *ap = mem;
+
+ ASSERT (ap != 0);
+ p = (struct mhead *) ap - 1;
+ ASSERT (p -> mh_alloc == ISALLOC);
+#ifdef rcheck
+ ASSERT (p -> mh_magic4 == MAGIC4);
+ ap += p -> mh_nbytes;
+ ASSERT (*ap++ == MAGIC1); ASSERT (*ap++ == MAGIC1);
+ ASSERT (*ap++ == MAGIC1); ASSERT (*ap == MAGIC1);
+#endif /* rcheck */
+ }
+ {
+ register int nunits = p -> mh_index;
+
+ ASSERT (nunits <= 29);
+ p -> mh_alloc = ISFREE;
+ CHAIN (p) = nextf[nunits];
+ nextf[nunits] = p;
+#ifdef MSTATS
+ nmalloc[nunits]--;
+ nfre++;
+#endif /* MSTATS */
+ }
+ }
+
+char *
+realloc (mem, n)
+ char *mem;
+ register unsigned n; {
+ register struct mhead *p;
+ register unsigned int tocopy;
+ register int nbytes;
+ register int nunits;
+
+ if ((p = (struct mhead *) mem) == 0)
+ return malloc (n);
+ p--;
+ nunits = p -> mh_index;
+ ASSERT (p -> mh_alloc == ISALLOC);
+#ifdef rcheck
+ ASSERT (p -> mh_magic4 == MAGIC4);
+ {
+ register char *m = mem + (tocopy = p -> mh_nbytes);
+ ASSERT (*m++ == MAGIC1); ASSERT (*m++ == MAGIC1);
+ ASSERT (*m++ == MAGIC1); ASSERT (*m == MAGIC1);
+ }
+#else
+ if (p -> mh_index >= 13)
+ tocopy = (1 << (p -> mh_index + 3)) - sizeof *p;
+ else
+ tocopy = p -> mh_size;
+#endif /* rcheck */
+
+ /* See if desired size rounds to same power of 2 as actual size. */
+ nbytes = (n + sizeof *p + EXTRA + 7) & ~7;
+
+ /* If ok, use the same block, just marking its size as changed. */
+ if (nbytes > (4 << nunits) && nbytes <= (8 << nunits)) {
+#ifdef rcheck
+ register char *m = mem + tocopy;
+ *m++ = 0; *m++ = 0; *m++ = 0; *m++ = 0;
+ p-> mh_nbytes = n;
+ m = mem + n;
+ *m++ = MAGIC1; *m++ = MAGIC1; *m++ = MAGIC1; *m++ = MAGIC1;
+#else
+ p -> mh_size = n;
+#endif /* rcheck */
+ return mem;}
+
+ if (n < tocopy)
+ tocopy = n;
+ {
+ register char *new;
+ void bcopy(); /*HMS: here? */
+
+ if ((new = malloc (n)) == 0)
+ return 0;
+ bcopy (mem, new, tocopy);
+ free (mem);
+ return new;
+ }
+ }
+
+#ifdef MSTATS
+/* Return statistics describing allocation of blocks of size 2**n. */
+
+struct mstats_value {
+ int blocksize;
+ int nfree;
+ int nused;
+ };
+
+struct mstats_value
+malloc_stats (size)
+ int size; {
+ struct mstats_value v;
+ register int i;
+ register struct mhead *p;
+
+ v.nfree = 0;
+
+ if (size < 0 || size >= 30) {
+ v.blocksize = 0;
+ v.nused = 0;
+ return v;}
+
+ v.blocksize = 1 << (size + 3);
+ v.nused = nmalloc[size];
+
+ for (p = nextf[size]; p; p = CHAIN (p))
+ v.nfree++;
+
+ return v;}
+#endif
+
+/* how much space is available? */
+
+unsigned freespace() {
+ register int i, j;
+ register struct mhead *p;
+ register unsigned space = 0;
+ int local; /* address only is used */
+
+ space = (char *)&local - sbrk(0); /* stack space */
+
+ for (i = 0; i < 30; i++) {
+ for (j = 0, p = nextf[i]; p; p = CHAIN (p), j++) ;
+ space += j * (1 << (i + 3));}
+
+ return(space);}
+
+/* How big is this cell? */
+
+unsigned mc_size(cp)
+ char *cp;{
+ register struct mhead *p;
+
+ if ((p = (struct mhead *) cp) == 0) {
+ /*HMS? */
+ }
+ p--;
+#ifdef rcheck
+ return p -> mh_nbytes;
+#else
+ return (1 << (p -> mh_index + 3)) - sizeof *p;
+#if 0
+ if (p -> mh_index >= 13)
+ return (1 << (p -> mh_index + 3)) - sizeof *p;
+ else
+ return p -> mh_size;
+#endif
+#endif /* rcheck */
+ }
+
+/*HMS: Really should use memcpy, if available... */
+
+void bcopy(source, dest, len)
+ register char *source, *dest;
+ register len; {
+ register i;
+
+ for (i = 0; i < len; i++)
+ *dest++ = *source++;}
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