diff options
Diffstat (limited to 'tools/build/v2/engine/boehm_gc/new_hblk.c')
| -rw-r--r-- | tools/build/v2/engine/boehm_gc/new_hblk.c | 201 |
1 files changed, 201 insertions, 0 deletions
diff --git a/tools/build/v2/engine/boehm_gc/new_hblk.c b/tools/build/v2/engine/boehm_gc/new_hblk.c new file mode 100644 index 0000000000..5d5a56f2af --- /dev/null +++ b/tools/build/v2/engine/boehm_gc/new_hblk.c @@ -0,0 +1,201 @@ +/* + * 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(size) + */ +/* 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 2 (words) cleared objects inside hblk h. + * Set the last link to + * be ofl. Return a pointer tpo the first free list entry. + */ +ptr_t GC_build_fl_clear2(struct hblk *h, ptr_t ofl) +{ + word * p = (word *)(h -> hb_body); + 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 4 cleared objects */ +ptr_t GC_build_fl_clear4(struct hblk *h, ptr_t ofl) +{ + word * p = (word *)(h -> hb_body); + 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(struct hblk *h, ptr_t ofl) +{ + word * p = (word *)(h -> hb_body); + 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(struct hblk *h, ptr_t ofl) +{ + word * p = (word *)(h -> hb_body); + 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(struct hblk *h, size_t 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 2: if (clear) { + return GC_build_fl_clear2(h, list); + } else { + return GC_build_fl2(h, list); + } + 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 = (word *)(h -> hb_body) + sz; /* second object in *h */ + prev = (word *)(h -> hb_body); /* 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 gran granules. + * 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(size_t gran, int kind) +{ + struct hblk *h; /* the new heap block */ + GC_bool clear = GC_obj_kinds[kind].ok_init; + + /* Ignore gcc "no effect" warning on the following: */ + GC_STATIC_ASSERT((sizeof (struct hblk)) == HBLKSIZE); + + if (GC_debugging_started) clear = TRUE; + + /* Allocate a new heap block */ + h = GC_allochblk(GRANULES_TO_BYTES(gran), 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[gran] = + GC_build_fl(h, GRANULES_TO_WORDS(gran), clear, + GC_obj_kinds[kind].ok_freelist[gran]); +} + |