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/*
* Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers
* Copyright (c) 1991-1994 by Xerox Corporation. All rights reserved.
* Copyright (c) 2000 by Hewlett-Packard Company. All rights reserved.
*
* THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
* OR IMPLIED. ANY USE IS AT YOUR OWN RISK.
*
* Permission is hereby granted to use or copy this program
* for any purpose, provided the above notices are retained on all copies.
* Permission to modify the code and to distribute modified code is granted,
* provided the above notices are retained, and a notice that the code was
* modified is included with the above copyright notice.
*
* This file contains the functions:
* ptr_t GC_build_flXXX(h, old_fl)
* void GC_new_hblk(n)
*/
/* Boehm, May 19, 1994 2:09 pm PDT */
# include <stdio.h>
# include "private/gc_priv.h"
#ifndef SMALL_CONFIG
/*
* Build a free list for size 1 objects inside hblk h. Set the last link to
* be ofl. Return a pointer tpo the first free list entry.
*/
ptr_t GC_build_fl1(h, ofl)
struct hblk *h;
ptr_t ofl;
{
register word * p = h -> hb_body;
register word * lim = (word *)(h + 1);
p[0] = (word)ofl;
p[1] = (word)(p);
p[2] = (word)(p+1);
p[3] = (word)(p+2);
p += 4;
for (; p < lim; p += 4) {
p[0] = (word)(p-1);
p[1] = (word)(p);
p[2] = (word)(p+1);
p[3] = (word)(p+2);
};
return((ptr_t)(p-1));
}
/* The same for size 2 cleared objects */
ptr_t GC_build_fl_clear2(h, ofl)
struct hblk *h;
ptr_t ofl;
{
register word * p = h -> hb_body;
register word * lim = (word *)(h + 1);
p[0] = (word)ofl;
p[1] = 0;
p[2] = (word)p;
p[3] = 0;
p += 4;
for (; p < lim; p += 4) {
p[0] = (word)(p-2);
p[1] = 0;
p[2] = (word)p;
p[3] = 0;
};
return((ptr_t)(p-2));
}
/* The same for size 3 cleared objects */
ptr_t GC_build_fl_clear3(h, ofl)
struct hblk *h;
ptr_t ofl;
{
register word * p = h -> hb_body;
register word * lim = (word *)(h + 1) - 2;
p[0] = (word)ofl;
p[1] = 0;
p[2] = 0;
p += 3;
for (; p < lim; p += 3) {
p[0] = (word)(p-3);
p[1] = 0;
p[2] = 0;
};
return((ptr_t)(p-3));
}
/* The same for size 4 cleared objects */
ptr_t GC_build_fl_clear4(h, ofl)
struct hblk *h;
ptr_t ofl;
{
register word * p = h -> hb_body;
register word * lim = (word *)(h + 1);
p[0] = (word)ofl;
p[1] = 0;
p[2] = 0;
p[3] = 0;
p += 4;
for (; p < lim; p += 4) {
PREFETCH_FOR_WRITE((ptr_t)(p+64));
p[0] = (word)(p-4);
p[1] = 0;
CLEAR_DOUBLE(p+2);
};
return((ptr_t)(p-4));
}
/* The same for size 2 uncleared objects */
ptr_t GC_build_fl2(h, ofl)
struct hblk *h;
ptr_t ofl;
{
register word * p = h -> hb_body;
register word * lim = (word *)(h + 1);
p[0] = (word)ofl;
p[2] = (word)p;
p += 4;
for (; p < lim; p += 4) {
p[0] = (word)(p-2);
p[2] = (word)p;
};
return((ptr_t)(p-2));
}
/* The same for size 4 uncleared objects */
ptr_t GC_build_fl4(h, ofl)
struct hblk *h;
ptr_t ofl;
{
register word * p = h -> hb_body;
register word * lim = (word *)(h + 1);
p[0] = (word)ofl;
p[4] = (word)p;
p += 8;
for (; p < lim; p += 8) {
PREFETCH_FOR_WRITE((ptr_t)(p+64));
p[0] = (word)(p-4);
p[4] = (word)p;
};
return((ptr_t)(p-4));
}
#endif /* !SMALL_CONFIG */
/* Build a free list for objects of size sz inside heap block h. */
/* Clear objects inside h if clear is set. Add list to the end of */
/* the free list we build. Return the new free list. */
/* This could be called without the main GC lock, if we ensure that */
/* there is no concurrent collection which might reclaim objects that */
/* we have not yet allocated. */
ptr_t GC_build_fl(h, sz, clear, list)
struct hblk *h;
word sz;
GC_bool clear;
ptr_t list;
{
word *p, *prev;
word *last_object; /* points to last object in new hblk */
/* Do a few prefetches here, just because its cheap. */
/* If we were more serious about it, these should go inside */
/* the loops. But write prefetches usually don't seem to */
/* matter much. */
PREFETCH_FOR_WRITE((ptr_t)h);
PREFETCH_FOR_WRITE((ptr_t)h + 128);
PREFETCH_FOR_WRITE((ptr_t)h + 256);
PREFETCH_FOR_WRITE((ptr_t)h + 378);
/* Handle small objects sizes more efficiently. For larger objects */
/* the difference is less significant. */
# ifndef SMALL_CONFIG
switch (sz) {
case 1: return GC_build_fl1(h, list);
case 2: if (clear) {
return GC_build_fl_clear2(h, list);
} else {
return GC_build_fl2(h, list);
}
case 3: if (clear) {
return GC_build_fl_clear3(h, list);
} else {
/* It's messy to do better than the default here. */
break;
}
case 4: if (clear) {
return GC_build_fl_clear4(h, list);
} else {
return GC_build_fl4(h, list);
}
default:
break;
}
# endif /* !SMALL_CONFIG */
/* Clear the page if necessary. */
if (clear) BZERO(h, HBLKSIZE);
/* Add objects to free list */
p = &(h -> hb_body[sz]); /* second object in *h */
prev = &(h -> hb_body[0]); /* One object behind p */
last_object = (word *)((char *)h + HBLKSIZE);
last_object -= sz;
/* Last place for last object to start */
/* make a list of all objects in *h with head as last object */
while (p <= last_object) {
/* current object's link points to last object */
obj_link(p) = (ptr_t)prev;
prev = p;
p += sz;
}
p -= sz; /* p now points to last object */
/*
* put p (which is now head of list of objects in *h) as first
* pointer in the appropriate free list for this size.
*/
obj_link(h -> hb_body) = list;
return ((ptr_t)p);
}
/*
* Allocate a new heapblock for small objects of size n.
* Add all of the heapblock's objects to the free list for objects
* of that size.
* Set all mark bits if objects are uncollectable.
* Will fail to do anything if we are out of memory.
*/
void GC_new_hblk(sz, kind)
register word sz;
int kind;
{
register struct hblk *h; /* the new heap block */
register GC_bool clear = GC_obj_kinds[kind].ok_init;
# ifdef PRINTSTATS
if ((sizeof (struct hblk)) > HBLKSIZE) {
ABORT("HBLK SZ inconsistency");
}
# endif
if (GC_debugging_started) clear = TRUE;
/* Allocate a new heap block */
h = GC_allochblk(sz, kind, 0);
if (h == 0) return;
/* Mark all objects if appropriate. */
if (IS_UNCOLLECTABLE(kind)) GC_set_hdr_marks(HDR(h));
/* Build the free list */
GC_obj_kinds[kind].ok_freelist[sz] =
GC_build_fl(h, sz, clear, GC_obj_kinds[kind].ok_freelist[sz]);
}
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