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authorIvan Maidanski <ivmai@mail.ru>2011-07-26 13:36:22 +0200
committerIvan Maidanski <ivmai@mail.ru>2011-07-26 13:36:22 +0200
commit29be14a4aa2f73bf89396e50e5f5322fa9264b00 (patch)
tree85fb9a7aa0e14ef35f73be40b00e0aedcb37cf96 /reclaim.c
parente955362cfcef47fdc3ad2140f50ea4638fd86a4d (diff)
gc5.3 tarball importgc5_3
Diffstat (limited to 'reclaim.c')
-rw-r--r--reclaim.c218
1 files changed, 201 insertions, 17 deletions
diff --git a/reclaim.c b/reclaim.c
index 3085946..4ace110 100644
--- a/reclaim.c
+++ b/reclaim.c
@@ -1,6 +1,8 @@
/*
* Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers
- * Copyright (c) 1991-1994 by Xerox Corporation. All rights reserved.
+ * Copyright (c) 1991-1996 by Xerox Corporation. All rights reserved.
+ * Copyright (c) 1996-1999 by Silicon Graphics. All rights reserved.
+ * Copyright (c) 1999 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.
@@ -11,7 +13,6 @@
* provided the above notices are retained, and a notice that the code was
* modified is included with the above copyright notice.
*/
-/* Boehm, February 15, 1996 2:41 pm PST */
#include <stdio.h>
#include "gc_priv.h"
@@ -28,13 +29,8 @@ word sz;
} else {
GC_err_printf0("Leaked composite object at ");
}
- if (GC_debugging_started && GC_has_debug_info(p)) {
- GC_print_obj(p);
- } else {
- GC_err_printf2("0x%lx (appr. size = %ld)\n",
- (unsigned long)p,
- (unsigned long)WORDS_TO_BYTES(sz));
- }
+ GC_print_heap_obj(p);
+ GC_err_printf0("\n");
}
# define FOUND_FREE(hblk, word_no) \
@@ -67,6 +63,139 @@ register hdr * hhdr;
return(TRUE);
}
+/* The following functions sometimes return a DONT_KNOW value. */
+#define DONT_KNOW 2
+
+#ifdef SMALL_CONFIG
+# define GC_block_nearly_full1(hhdr, pat1) DONT_KNOW
+# define GC_block_nearly_full3(hhdr, pat1, pat2) DONT_KNOW
+# define GC_block_nearly_full(hhdr) DONT_KNOW
+#else
+
+/*
+ * Test whether nearly all of the mark words consist of the same
+ * repeating pattern.
+ */
+#define FULL_THRESHOLD (MARK_BITS_SZ/16)
+
+GC_bool GC_block_nearly_full1(hhdr, pat1)
+hdr *hhdr;
+word pat1;
+{
+ unsigned i;
+ unsigned misses = 0;
+ GC_ASSERT((MARK_BITS_SZ & 1) == 0);
+ for (i = 0; i < MARK_BITS_SZ; ++i) {
+ if ((hhdr -> hb_marks[i] | ~pat1) != ONES) {
+ if (++misses > FULL_THRESHOLD) return FALSE;
+ }
+ }
+ return TRUE;
+}
+
+/*
+ * Test whether the same repeating 3 word pattern occurs in nearly
+ * all the mark bit slots.
+ * This is used as a heuristic, so we're a bit sloppy and ignore
+ * the last one or two words.
+ */
+GC_bool GC_block_nearly_full3(hhdr, pat1, pat2, pat3)
+hdr *hhdr;
+word pat1, pat2, pat3;
+{
+ unsigned i;
+ unsigned misses = 0;
+
+ if (MARK_BITS_SZ < 4) {
+ return DONT_KNOW;
+ }
+ for (i = 0; i < MARK_BITS_SZ - 2; i += 3) {
+ if ((hhdr -> hb_marks[i] | ~pat1) != ONES) {
+ if (++misses > FULL_THRESHOLD) return FALSE;
+ }
+ if ((hhdr -> hb_marks[i+1] | ~pat2) != ONES) {
+ if (++misses > FULL_THRESHOLD) return FALSE;
+ }
+ if ((hhdr -> hb_marks[i+2] | ~pat3) != ONES) {
+ if (++misses > FULL_THRESHOLD) return FALSE;
+ }
+ }
+ return TRUE;
+}
+
+/* Check whether a small object block is nearly full by looking at only */
+/* the mark bits. */
+/* We manually precomputed the mark bit patterns that need to be */
+/* checked for, and we give up on the ones that are unlikely to occur, */
+/* or have period > 3. */
+/* This would be a lot easier with a mark bit per object instead of per */
+/* word, but that would rewuire computing object numbers in the mark */
+/* loop, which would require different data structures ... */
+GC_bool GC_block_nearly_full(hhdr)
+hdr *hhdr;
+{
+ int sz = hhdr -> hb_sz;
+
+# if CPP_WORDSZ != 32 && CPP_WORDSZ != 64
+ return DONT_KNOW; /* Shouldn't be used in any standard config. */
+# endif
+ if (0 != HDR_WORDS) return DONT_KNOW;
+ /* Also shouldn't happen */
+# if CPP_WORDSZ == 32
+ switch(sz) {
+ case 1:
+ return GC_block_nearly_full1(hhdr, 0xffffffffl);
+ case 2:
+ return GC_block_nearly_full1(hhdr, 0x55555555l);
+ case 4:
+ return GC_block_nearly_full1(hhdr, 0x11111111l);
+ case 6:
+ return GC_block_nearly_full3(hhdr, 0x41041041l,
+ 0x10410410l,
+ 0x04104104l);
+ case 8:
+ return GC_block_nearly_full1(hhdr, 0x01010101l);
+ case 12:
+ return GC_block_nearly_full3(hhdr, 0x01001001l,
+ 0x10010010l,
+ 0x00100100l);
+ case 16:
+ return GC_block_nearly_full1(hhdr, 0x00010001l);
+ case 32:
+ return GC_block_nearly_full1(hhdr, 0x00000001l);
+ default:
+ return DONT_KNOW;
+ }
+# endif
+# if CPP_WORDSZ == 64
+ switch(sz) {
+ case 1:
+ return GC_block_nearly_full1(hhdr, 0xffffffffffffffffl);
+ case 2:
+ return GC_block_nearly_full1(hhdr, 0x5555555555555555l);
+ case 4:
+ return GC_block_nearly_full1(hhdr, 0x1111111111111111l);
+ case 6:
+ return GC_block_nearly_full3(hhdr, 0x1041041041041041l,
+ 0x4104104104104104l,
+ 0x0410410410410410l);
+ case 8:
+ return GC_block_nearly_full1(hhdr, 0x0101010101010101l);
+ case 12:
+ return GC_block_nearly_full3(hhdr, 0x1001001001001001l,
+ 0x0100100100100100l,
+ 0x0010010010010010l);
+ case 16:
+ return GC_block_nearly_full1(hhdr, 0x0001000100010001l);
+ case 32:
+ return GC_block_nearly_full1(hhdr, 0x0000000100000001l);
+ default:
+ return DONT_KNOW;
+ }
+# endif
+}
+#endif /* !SMALL_CONFIG */
+
# ifdef GATHERSTATS
# define INCR_WORDS(sz) n_words_found += (sz)
# else
@@ -187,8 +316,7 @@ register ptr_t list;
p[start_displ] = (word)list; \
list = (ptr_t)(p+start_displ); \
p[start_displ+1] = 0; \
- p[start_displ+2] = 0; \
- p[start_displ+3] = 0; \
+ CLEAR_DOUBLE(p + start_displ + 2); \
INCR_WORDS(4); \
}
@@ -448,10 +576,11 @@ register struct hblk *hbp; /* ptr to current heap block */
int report_if_found; /* Abort if a reclaimable object is found */
{
hdr * hhdr;
- register word sz; /* size of objects in current block */
- register struct obj_kind * ok;
- register ptr_t * flh;
- register int kind;
+ word sz; /* size of objects in current block */
+ struct obj_kind * ok;
+ ptr_t * flh;
+ int kind;
+ GC_bool full;
hhdr = HDR(hbp);
sz = hhdr -> hb_sz;
@@ -459,7 +588,6 @@ int report_if_found; /* Abort if a reclaimable object is found */
kind = hhdr -> hb_obj_kind;
ok = &GC_obj_kinds[kind];
flh = &(ok -> ok_freelist[sz]);
- GC_write_hint(hbp);
if (report_if_found) {
GC_reclaim_check(hbp, hhdr, sz);
@@ -467,16 +595,41 @@ int report_if_found; /* Abort if a reclaimable object is found */
switch(sz) {
# ifndef SMALL_CONFIG
case 1:
+# if CPP_WORDSZ == 64
+ full = GC_block_nearly_full1(hhdr, 0xffffffffffffffffl);
+# else
+ full = GC_block_nearly_full1(hhdr, 0xffffffffl);
+# endif
+ if (TRUE == full) goto out;
+ if (FALSE == full) GC_write_hint(hbp);
+ /* In the DONT_KNOW case, we let reclaim fault. */
*flh = GC_reclaim1(hbp, hhdr, *flh);
break;
case 2:
+# if CPP_WORDSZ == 64
+ full = GC_block_nearly_full1(hhdr, 0x5555555555555555l);
+# else
+ full = GC_block_nearly_full1(hhdr, 0x55555555l);
+# endif
+ if (TRUE == full) goto out;
+ if (FALSE == full) GC_write_hint(hbp);
*flh = GC_reclaim_clear2(hbp, hhdr, *flh);
break;
case 4:
+# if CPP_WORDSZ == 64
+ full = GC_block_nearly_full1(hhdr, 0x1111111111111111l);
+# else
+ full = GC_block_nearly_full1(hhdr, 0x11111111l);
+# endif
+ if (TRUE == full) goto out;
+ if (FALSE == full) GC_write_hint(hbp);
*flh = GC_reclaim_clear4(hbp, hhdr, *flh);
break;
# endif
default:
+ full = GC_block_nearly_full(hhdr);
+ if (TRUE == full) goto out;
+ if (FALSE == full) GC_write_hint(hbp);
*flh = GC_reclaim_clear(hbp, hhdr, sz, *flh);
break;
}
@@ -484,20 +637,45 @@ int report_if_found; /* Abort if a reclaimable object is found */
switch(sz) {
# ifndef SMALL_CONFIG
case 1:
+# if CPP_WORDSZ == 64
+ full = GC_block_nearly_full1(hhdr, 0xffffffffffffffffl);
+# else
+ full = GC_block_nearly_full1(hhdr, 0xffffffffl);
+# endif
+ if (TRUE == full) goto out;
+ if (FALSE == full) GC_write_hint(hbp);
*flh = GC_reclaim1(hbp, hhdr, *flh);
break;
case 2:
+# if CPP_WORDSZ == 64
+ full = GC_block_nearly_full1(hhdr, 0x5555555555555555l);
+# else
+ full = GC_block_nearly_full1(hhdr, 0x55555555l);
+# endif
+ if (TRUE == full) goto out;
+ if (FALSE == full) GC_write_hint(hbp);
*flh = GC_reclaim_uninit2(hbp, hhdr, *flh);
break;
case 4:
+# if CPP_WORDSZ == 64
+ full = GC_block_nearly_full1(hhdr, 0x1111111111111111l);
+# else
+ full = GC_block_nearly_full1(hhdr, 0x11111111l);
+# endif
+ if (TRUE == full) goto out;
+ if (FALSE == full) GC_write_hint(hbp);
*flh = GC_reclaim_uninit4(hbp, hhdr, *flh);
break;
# endif
default:
+ full = GC_block_nearly_full(hhdr);
+ if (TRUE == full) goto out;
+ if (FALSE == full) GC_write_hint(hbp);
*flh = GC_reclaim_uninit(hbp, hhdr, sz, *flh);
break;
}
}
+out:
if (IS_UNCOLLECTABLE(kind)) GC_set_hdr_marks(hhdr);
}
@@ -654,6 +832,12 @@ int report_if_found; /* Abort if a GC_reclaimable object is found */
/* Go through all heap blocks (in hblklist) and reclaim unmarked objects */
/* or enqueue the block for later processing. */
GC_apply_to_all_blocks(GC_reclaim_block, (word)report_if_found);
+
+# ifdef EAGER_SWEEP
+ /* This is a very stupid thing to do. We make it possible anyway, */
+ /* so that you can convince yourself that it really is very stupid. */
+ GC_reclaim_all((GC_stop_func)0, FALSE);
+# endif
}
@@ -687,7 +871,7 @@ int kind;
* Abort and return FALSE when/if (*stop_func)() returns TRUE.
* If this returns TRUE, then it's safe to restart the world
* with incorrectly cleared mark bits.
- * If ignore_old is TRUE, then reclain only blocks that have been
+ * If ignore_old is TRUE, then reclaim only blocks that have been
* recently reclaimed, and discard the rest.
* Stop_func may be 0.
*/