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-rw-r--r--boehm-gc/new_hblk.c263
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diff --git a/boehm-gc/new_hblk.c b/boehm-gc/new_hblk.c
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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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