--- /dev/null
+
+/*
+ * Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers
+ * Copyright (c) 1991-1995 by Xerox Corporation. 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.
+ *
+ */
+
+
+# include <stdio.h>
+# include "gc_priv.h"
+# include "gc_mark.h"
+
+/* We put this here to minimize the risk of inlining. */
+/*VARARGS*/
+void GC_noop() {}
+
+/* Single argument version, robust against whole program analysis. */
+void GC_noop1(x)
+word x;
+{
+ static VOLATILE word sink;
+
+ sink = x;
+}
+
+mark_proc GC_mark_procs[MAX_MARK_PROCS] = {0};
+word GC_n_mark_procs = 0;
+
+/* Initialize GC_obj_kinds properly and standard free lists properly. */
+/* This must be done statically since they may be accessed before */
+/* GC_init is called. */
+/* It's done here, since we need to deal with mark descriptors. */
+struct obj_kind GC_obj_kinds[MAXOBJKINDS] = {
+/* PTRFREE */ { &GC_aobjfreelist[0], 0 /* filled in dynamically */,
+ 0 | DS_LENGTH, FALSE, FALSE },
+/* NORMAL */ { &GC_objfreelist[0], 0,
+# if defined(ADD_BYTE_AT_END) && ALIGNMENT > DS_TAGS
+ (word)(-ALIGNMENT) | DS_LENGTH,
+# else
+ 0 | DS_LENGTH,
+# endif
+ TRUE /* add length to descr */, TRUE },
+/* UNCOLLECTABLE */
+ { &GC_uobjfreelist[0], 0,
+ 0 | DS_LENGTH, TRUE /* add length to descr */, TRUE },
+# ifdef ATOMIC_UNCOLLECTABLE
+ /* AUNCOLLECTABLE */
+ { &GC_auobjfreelist[0], 0,
+ 0 | DS_LENGTH, FALSE /* add length to descr */, FALSE },
+# endif
+# ifdef STUBBORN_ALLOC
+/*STUBBORN*/ { &GC_sobjfreelist[0], 0,
+ 0 | DS_LENGTH, TRUE /* add length to descr */, TRUE },
+# endif
+};
+
+# ifdef ATOMIC_UNCOLLECTABLE
+# ifdef STUBBORN_ALLOC
+ int GC_n_kinds = 5;
+# else
+ int GC_n_kinds = 4;
+# endif
+# else
+# ifdef STUBBORN_ALLOC
+ int GC_n_kinds = 4;
+# else
+ int GC_n_kinds = 3;
+# endif
+# endif
+
+
+# ifndef INITIAL_MARK_STACK_SIZE
+# define INITIAL_MARK_STACK_SIZE (1*HBLKSIZE)
+ /* INITIAL_MARK_STACK_SIZE * sizeof(mse) should be a */
+ /* multiple of HBLKSIZE. */
+# endif
+
+/*
+ * Limits of stack for GC_mark routine.
+ * All ranges between GC_mark_stack(incl.) and GC_mark_stack_top(incl.) still
+ * need to be marked from.
+ */
+
+word GC_n_rescuing_pages; /* Number of dirty pages we marked from */
+ /* excludes ptrfree pages, etc. */
+
+mse * GC_mark_stack;
+
+word GC_mark_stack_size = 0;
+
+mse * GC_mark_stack_top;
+
+static struct hblk * scan_ptr;
+
+mark_state_t GC_mark_state = MS_NONE;
+
+GC_bool GC_mark_stack_too_small = FALSE;
+
+GC_bool GC_objects_are_marked = FALSE; /* Are there collectable marked */
+ /* objects in the heap? */
+
+GC_bool GC_collection_in_progress()
+{
+ return(GC_mark_state != MS_NONE);
+}
+
+/* clear all mark bits in the header */
+void GC_clear_hdr_marks(hhdr)
+register hdr * hhdr;
+{
+ BZERO(hhdr -> hb_marks, MARK_BITS_SZ*sizeof(word));
+}
+
+/* Set all mark bits in the header. Used for uncollectable blocks. */
+void GC_set_hdr_marks(hhdr)
+register hdr * hhdr;
+{
+ register int i;
+
+ for (i = 0; i < MARK_BITS_SZ; ++i) {
+ hhdr -> hb_marks[i] = ONES;
+ }
+}
+
+/*
+ * Clear all mark bits associated with block h.
+ */
+/*ARGSUSED*/
+static void clear_marks_for_block(h, dummy)
+struct hblk *h;
+word dummy;
+{
+ register hdr * hhdr = HDR(h);
+
+ if (IS_UNCOLLECTABLE(hhdr -> hb_obj_kind)) return;
+ /* Mark bit for these is cleared only once the object is */
+ /* explicitly deallocated. This either frees the block, or */
+ /* the bit is cleared once the object is on the free list. */
+ GC_clear_hdr_marks(hhdr);
+}
+
+/* Slow but general routines for setting/clearing/asking about mark bits */
+void GC_set_mark_bit(p)
+ptr_t p;
+{
+ register struct hblk *h = HBLKPTR(p);
+ register hdr * hhdr = HDR(h);
+ register int word_no = (word *)p - (word *)h;
+
+ set_mark_bit_from_hdr(hhdr, word_no);
+}
+
+void GC_clear_mark_bit(p)
+ptr_t p;
+{
+ register struct hblk *h = HBLKPTR(p);
+ register hdr * hhdr = HDR(h);
+ register int word_no = (word *)p - (word *)h;
+
+ clear_mark_bit_from_hdr(hhdr, word_no);
+}
+
+GC_bool GC_is_marked(p)
+ptr_t p;
+{
+ register struct hblk *h = HBLKPTR(p);
+ register hdr * hhdr = HDR(h);
+ register int word_no = (word *)p - (word *)h;
+
+ return(mark_bit_from_hdr(hhdr, word_no));
+}
+
+
+/*
+ * Clear mark bits in all allocated heap blocks. This invalidates
+ * the marker invariant, and sets GC_mark_state to reflect this.
+ * (This implicitly starts marking to reestablish the invariant.)
+ */
+void GC_clear_marks()
+{
+ GC_apply_to_all_blocks(clear_marks_for_block, (word)0);
+ GC_objects_are_marked = FALSE;
+ GC_mark_state = MS_INVALID;
+ scan_ptr = 0;
+# ifdef GATHERSTATS
+ /* Counters reflect currently marked objects: reset here */
+ GC_composite_in_use = 0;
+ GC_atomic_in_use = 0;
+# endif
+
+}
+
+/* Initiate a garbage collection. Initiates a full collection if the */
+/* mark state is invalid. */
+/*ARGSUSED*/
+void GC_initiate_gc()
+{
+ if (GC_dirty_maintained) GC_read_dirty();
+# ifdef STUBBORN_ALLOC
+ GC_read_changed();
+# endif
+# ifdef CHECKSUMS
+ {
+ extern void GC_check_dirty();
+
+ if (GC_dirty_maintained) GC_check_dirty();
+ }
+# endif
+# ifdef GATHERSTATS
+ GC_n_rescuing_pages = 0;
+# endif
+ if (GC_mark_state == MS_NONE) {
+ GC_mark_state = MS_PUSH_RESCUERS;
+ } else if (GC_mark_state != MS_INVALID) {
+ ABORT("unexpected state");
+ } /* else this is really a full collection, and mark */
+ /* bits are invalid. */
+ scan_ptr = 0;
+}
+
+
+static void alloc_mark_stack();
+
+/* Perform a small amount of marking. */
+/* We try to touch roughly a page of memory. */
+/* Return TRUE if we just finished a mark phase. */
+GC_bool GC_mark_some()
+{
+ switch(GC_mark_state) {
+ case MS_NONE:
+ return(FALSE);
+
+ case MS_PUSH_RESCUERS:
+ if (GC_mark_stack_top
+ >= GC_mark_stack + INITIAL_MARK_STACK_SIZE/4) {
+ GC_mark_from_mark_stack();
+ return(FALSE);
+ } else {
+ scan_ptr = GC_push_next_marked_dirty(scan_ptr);
+ if (scan_ptr == 0) {
+# ifdef PRINTSTATS
+ GC_printf1("Marked from %lu dirty pages\n",
+ (unsigned long)GC_n_rescuing_pages);
+# endif
+ GC_push_roots(FALSE);
+ GC_objects_are_marked = TRUE;
+ if (GC_mark_state != MS_INVALID) {
+ GC_mark_state = MS_ROOTS_PUSHED;
+ }
+ }
+ }
+ return(FALSE);
+
+ case MS_PUSH_UNCOLLECTABLE:
+ if (GC_mark_stack_top
+ >= GC_mark_stack + INITIAL_MARK_STACK_SIZE/4) {
+ GC_mark_from_mark_stack();
+ return(FALSE);
+ } else {
+ scan_ptr = GC_push_next_marked_uncollectable(scan_ptr);
+ if (scan_ptr == 0) {
+ GC_push_roots(TRUE);
+ GC_objects_are_marked = TRUE;
+ if (GC_mark_state != MS_INVALID) {
+ GC_mark_state = MS_ROOTS_PUSHED;
+ }
+ }
+ }
+ return(FALSE);
+
+ case MS_ROOTS_PUSHED:
+ if (GC_mark_stack_top >= GC_mark_stack) {
+ GC_mark_from_mark_stack();
+ return(FALSE);
+ } else {
+ GC_mark_state = MS_NONE;
+ if (GC_mark_stack_too_small) {
+ alloc_mark_stack(2*GC_mark_stack_size);
+ }
+ return(TRUE);
+ }
+
+ case MS_INVALID:
+ case MS_PARTIALLY_INVALID:
+ if (!GC_objects_are_marked) {
+ GC_mark_state = MS_PUSH_UNCOLLECTABLE;
+ return(FALSE);
+ }
+ if (GC_mark_stack_top >= GC_mark_stack) {
+ GC_mark_from_mark_stack();
+ return(FALSE);
+ }
+ if (scan_ptr == 0
+ && (GC_mark_state == MS_INVALID || GC_mark_stack_too_small)) {
+ alloc_mark_stack(2*GC_mark_stack_size);
+ GC_mark_state = MS_PARTIALLY_INVALID;
+ }
+ scan_ptr = GC_push_next_marked(scan_ptr);
+ if (scan_ptr == 0 && GC_mark_state == MS_PARTIALLY_INVALID) {
+ GC_push_roots(TRUE);
+ GC_objects_are_marked = TRUE;
+ if (GC_mark_state != MS_INVALID) {
+ GC_mark_state = MS_ROOTS_PUSHED;
+ }
+ }
+ return(FALSE);
+ default:
+ ABORT("GC_mark_some: bad state");
+ return(FALSE);
+ }
+}
+
+
+GC_bool GC_mark_stack_empty()
+{
+ return(GC_mark_stack_top < GC_mark_stack);
+}
+
+#ifdef PROF_MARKER
+ word GC_prof_array[10];
+# define PROF(n) GC_prof_array[n]++
+#else
+# define PROF(n)
+#endif
+
+/* Given a pointer to someplace other than a small object page or the */
+/* first page of a large object, return a pointer either to the */
+/* start of the large object or NIL. */
+/* In the latter case black list the address current. */
+/* Returns NIL without black listing if current points to a block */
+/* with IGNORE_OFF_PAGE set. */
+/*ARGSUSED*/
+# ifdef PRINT_BLACK_LIST
+ word GC_find_start(current, hhdr, source)
+ word source;
+# else
+ word GC_find_start(current, hhdr)
+# define source 0
+# endif
+register word current;
+register hdr * hhdr;
+{
+# ifdef ALL_INTERIOR_POINTERS
+ if (hhdr != 0) {
+ register word orig = current;
+
+ current = (word)HBLKPTR(current) + HDR_BYTES;
+ do {
+ current = current - HBLKSIZE*(word)hhdr;
+ hhdr = HDR(current);
+ } while(IS_FORWARDING_ADDR_OR_NIL(hhdr));
+ /* current points to the start of the large object */
+ if (hhdr -> hb_flags & IGNORE_OFF_PAGE) return(0);
+ if ((word *)orig - (word *)current
+ >= (ptrdiff_t)(hhdr->hb_sz)) {
+ /* Pointer past the end of the block */
+ GC_ADD_TO_BLACK_LIST_NORMAL(orig, source);
+ return(0);
+ }
+ return(current);
+ } else {
+ GC_ADD_TO_BLACK_LIST_NORMAL(current, source);
+ return(0);
+ }
+# else
+ GC_ADD_TO_BLACK_LIST_NORMAL(current, source);
+ return(0);
+# endif
+# undef source
+}
+
+void GC_invalidate_mark_state()
+{
+ GC_mark_state = MS_INVALID;
+ GC_mark_stack_top = GC_mark_stack-1;
+}
+
+mse * GC_signal_mark_stack_overflow(msp)
+mse * msp;
+{
+ GC_mark_state = MS_INVALID;
+# ifdef PRINTSTATS
+ GC_printf1("Mark stack overflow; current size = %lu entries\n",
+ GC_mark_stack_size);
+# endif
+ return(msp-INITIAL_MARK_STACK_SIZE/8);
+}
+
+
+/*
+ * Mark objects pointed to by the regions described by
+ * mark stack entries between GC_mark_stack and GC_mark_stack_top,
+ * inclusive. Assumes the upper limit of a mark stack entry
+ * is never 0. A mark stack entry never has size 0.
+ * We try to traverse on the order of a hblk of memory before we return.
+ * Caller is responsible for calling this until the mark stack is empty.
+ */
+void GC_mark_from_mark_stack()
+{
+ mse * GC_mark_stack_reg = GC_mark_stack;
+ mse * GC_mark_stack_top_reg = GC_mark_stack_top;
+ mse * mark_stack_limit = &(GC_mark_stack[GC_mark_stack_size]);
+ int credit = HBLKSIZE; /* Remaining credit for marking work */
+ register word * current_p; /* Pointer to current candidate ptr. */
+ register word current; /* Candidate pointer. */
+ register word * limit; /* (Incl) limit of current candidate */
+ /* range */
+ register word descr;
+ register ptr_t greatest_ha = GC_greatest_plausible_heap_addr;
+ register ptr_t least_ha = GC_least_plausible_heap_addr;
+# define SPLIT_RANGE_WORDS 128 /* Must be power of 2. */
+
+ GC_objects_are_marked = TRUE;
+# ifdef OS2 /* Use untweaked version to circumvent compiler problem */
+ while (GC_mark_stack_top_reg >= GC_mark_stack_reg && credit >= 0) {
+# else
+ while ((((ptr_t)GC_mark_stack_top_reg - (ptr_t)GC_mark_stack_reg) | credit)
+ >= 0) {
+# endif
+ current_p = GC_mark_stack_top_reg -> mse_start;
+ retry:
+ descr = GC_mark_stack_top_reg -> mse_descr;
+ if (descr & ((~(WORDS_TO_BYTES(SPLIT_RANGE_WORDS) - 1)) | DS_TAGS)) {
+ word tag = descr & DS_TAGS;
+
+ switch(tag) {
+ case DS_LENGTH:
+ /* Large length. */
+ /* Process part of the range to avoid pushing too much on the */
+ /* stack. */
+ GC_mark_stack_top_reg -> mse_start =
+ limit = current_p + SPLIT_RANGE_WORDS-1;
+ GC_mark_stack_top_reg -> mse_descr -=
+ WORDS_TO_BYTES(SPLIT_RANGE_WORDS-1);
+ /* Make sure that pointers overlapping the two ranges are */
+ /* considered. */
+ limit = (word *)((char *)limit + sizeof(word) - ALIGNMENT);
+ break;
+ case DS_BITMAP:
+ GC_mark_stack_top_reg--;
+ descr &= ~DS_TAGS;
+ credit -= WORDS_TO_BYTES(WORDSZ/2); /* guess */
+ while (descr != 0) {
+ if ((signed_word)descr < 0) {
+ current = *current_p;
+ if ((ptr_t)current >= least_ha && (ptr_t)current < greatest_ha) {
+ PUSH_CONTENTS(current, GC_mark_stack_top_reg, mark_stack_limit,
+ current_p, exit1);
+ }
+ }
+ descr <<= 1;
+ ++ current_p;
+ }
+ continue;
+ case DS_PROC:
+ GC_mark_stack_top_reg--;
+ credit -= PROC_BYTES;
+ GC_mark_stack_top_reg =
+ (*PROC(descr))
+ (current_p, GC_mark_stack_top_reg,
+ mark_stack_limit, ENV(descr));
+ continue;
+ case DS_PER_OBJECT:
+ GC_mark_stack_top_reg -> mse_descr =
+ *(word *)((ptr_t)current_p + descr - tag);
+ goto retry;
+ }
+ } else {
+ GC_mark_stack_top_reg--;
+ limit = (word *)(((ptr_t)current_p) + (word)descr);
+ }
+ /* The simple case in which we're scanning a range. */
+ credit -= (ptr_t)limit - (ptr_t)current_p;
+ limit -= 1;
+ while (current_p <= limit) {
+ current = *current_p;
+ if ((ptr_t)current >= least_ha && (ptr_t)current < greatest_ha) {
+ PUSH_CONTENTS(current, GC_mark_stack_top_reg,
+ mark_stack_limit, current_p, exit2);
+ }
+ current_p = (word *)((char *)current_p + ALIGNMENT);
+ }
+ }
+ GC_mark_stack_top = GC_mark_stack_top_reg;
+}
+
+/* Allocate or reallocate space for mark stack of size s words */
+/* May silently fail. */
+static void alloc_mark_stack(n)
+word n;
+{
+ mse * new_stack = (mse *)GC_scratch_alloc(n * sizeof(struct ms_entry));
+
+ GC_mark_stack_too_small = FALSE;
+ if (GC_mark_stack_size != 0) {
+ if (new_stack != 0) {
+ word displ = (word)GC_mark_stack & (GC_page_size - 1);
+ word size = GC_mark_stack_size * sizeof(struct ms_entry);
+
+ /* Recycle old space */
+ if (0 != displ) displ = GC_page_size - displ;
+ size = (size - displ) & ~(GC_page_size - 1);
+ GC_add_to_heap((struct hblk *)
+ ((word)GC_mark_stack + displ), size);
+ GC_mark_stack = new_stack;
+ GC_mark_stack_size = n;
+# ifdef PRINTSTATS
+ GC_printf1("Grew mark stack to %lu frames\n",
+ (unsigned long) GC_mark_stack_size);
+# endif
+ } else {
+# ifdef PRINTSTATS
+ GC_printf1("Failed to grow mark stack to %lu frames\n",
+ (unsigned long) n);
+# endif
+ }
+ } else {
+ if (new_stack == 0) {
+ GC_err_printf0("No space for mark stack\n");
+ EXIT();
+ }
+ GC_mark_stack = new_stack;
+ GC_mark_stack_size = n;
+ }
+ GC_mark_stack_top = GC_mark_stack-1;
+}
+
+void GC_mark_init()
+{
+ alloc_mark_stack(INITIAL_MARK_STACK_SIZE);
+}
+
+/*
+ * Push all locations between b and t onto the mark stack.
+ * b is the first location to be checked. t is one past the last
+ * location to be checked.
+ * Should only be used if there is no possibility of mark stack
+ * overflow.
+ */
+void GC_push_all(bottom, top)
+ptr_t bottom;
+ptr_t top;
+{
+ register word length;
+
+ bottom = (ptr_t)(((word) bottom + ALIGNMENT-1) & ~(ALIGNMENT-1));
+ top = (ptr_t)(((word) top) & ~(ALIGNMENT-1));
+ if (top == 0 || bottom == top) return;
+ GC_mark_stack_top++;
+ if (GC_mark_stack_top >= GC_mark_stack + GC_mark_stack_size) {
+ ABORT("unexpected mark stack overflow");
+ }
+ length = top - bottom;
+# if DS_TAGS > ALIGNMENT - 1
+ length += DS_TAGS;
+ length &= ~DS_TAGS;
+# endif
+ GC_mark_stack_top -> mse_start = (word *)bottom;
+ GC_mark_stack_top -> mse_descr = length;
+}
+
+/*
+ * Analogous to the above, but push only those pages that may have been
+ * dirtied. A block h is assumed dirty if dirty_fn(h) != 0.
+ * We use push_fn to actually push the block.
+ * Will not overflow mark stack if push_fn pushes a small fixed number
+ * of entries. (This is invoked only if push_fn pushes a single entry,
+ * or if it marks each object before pushing it, thus ensuring progress
+ * in the event of a stack overflow.)
+ */
+void GC_push_dirty(bottom, top, dirty_fn, push_fn)
+ptr_t bottom;
+ptr_t top;
+int (*dirty_fn)(/* struct hblk * h */);
+void (*push_fn)(/* ptr_t bottom, ptr_t top */);
+{
+ register struct hblk * h;
+
+ bottom = (ptr_t)(((long) bottom + ALIGNMENT-1) & ~(ALIGNMENT-1));
+ top = (ptr_t)(((long) top) & ~(ALIGNMENT-1));
+
+ if (top == 0 || bottom == top) return;
+ h = HBLKPTR(bottom + HBLKSIZE);
+ if (top <= (ptr_t) h) {
+ if ((*dirty_fn)(h-1)) {
+ (*push_fn)(bottom, top);
+ }
+ return;
+ }
+ if ((*dirty_fn)(h-1)) {
+ (*push_fn)(bottom, (ptr_t)h);
+ }
+ while ((ptr_t)(h+1) <= top) {
+ if ((*dirty_fn)(h)) {
+ if ((word)(GC_mark_stack_top - GC_mark_stack)
+ > 3 * GC_mark_stack_size / 4) {
+ /* Danger of mark stack overflow */
+ (*push_fn)((ptr_t)h, top);
+ return;
+ } else {
+ (*push_fn)((ptr_t)h, (ptr_t)(h+1));
+ }
+ }
+ h++;
+ }
+ if ((ptr_t)h != top) {
+ if ((*dirty_fn)(h)) {
+ (*push_fn)((ptr_t)h, top);
+ }
+ }
+ if (GC_mark_stack_top >= GC_mark_stack + GC_mark_stack_size) {
+ ABORT("unexpected mark stack overflow");
+ }
+}
+
+# ifndef SMALL_CONFIG
+void GC_push_conditional(bottom, top, all)
+ptr_t bottom;
+ptr_t top;
+int all;
+{
+ if (all) {
+ if (GC_dirty_maintained) {
+# ifdef PROC_VDB
+ /* Pages that were never dirtied cannot contain pointers */
+ GC_push_dirty(bottom, top, GC_page_was_ever_dirty, GC_push_all);
+# else
+ GC_push_all(bottom, top);
+# endif
+ } else {
+ GC_push_all(bottom, top);
+ }
+ } else {
+ GC_push_dirty(bottom, top, GC_page_was_dirty, GC_push_all);
+ }
+}
+#endif
+
+# ifdef MSWIN32
+ void __cdecl GC_push_one(p)
+# else
+ void GC_push_one(p)
+# endif
+word p;
+{
+ GC_PUSH_ONE_STACK(p);
+}
+
+# ifdef __STDC__
+# define BASE(p) (word)GC_base((void *)(p))
+# else
+# define BASE(p) (word)GC_base((char *)(p))
+# endif
+
+/* As above, but argument passed preliminary test. */
+# ifdef PRINT_BLACK_LIST
+ void GC_push_one_checked(p, interior_ptrs, source)
+ ptr_t source;
+# else
+ void GC_push_one_checked(p, interior_ptrs)
+# define source 0
+# endif
+register word p;
+register GC_bool interior_ptrs;
+{
+ register word r;
+ register hdr * hhdr;
+ register int displ;
+
+ GET_HDR(p, hhdr);
+ if (IS_FORWARDING_ADDR_OR_NIL(hhdr)) {
+ if (hhdr != 0 && interior_ptrs) {
+ r = BASE(p);
+ hhdr = HDR(r);
+ displ = BYTES_TO_WORDS(HBLKDISPL(r));
+ } else {
+ hhdr = 0;
+ }
+ } else {
+ register map_entry_type map_entry;
+
+ displ = HBLKDISPL(p);
+ map_entry = MAP_ENTRY((hhdr -> hb_map), displ);
+ if (map_entry == OBJ_INVALID) {
+ if (interior_ptrs) {
+ r = BASE(p);
+ displ = BYTES_TO_WORDS(HBLKDISPL(r));
+ if (r == 0) hhdr = 0;
+ } else {
+ hhdr = 0;
+ }
+ } else {
+ displ = BYTES_TO_WORDS(displ);
+ displ -= map_entry;
+ r = (word)((word *)(HBLKPTR(p)) + displ);
+ }
+ }
+ /* If hhdr != 0 then r == GC_base(p), only we did it faster. */
+ /* displ is the word index within the block. */
+ if (hhdr == 0) {
+ if (interior_ptrs) {
+# ifdef PRINT_BLACK_LIST
+ GC_add_to_black_list_stack(p, source);
+# else
+ GC_add_to_black_list_stack(p);
+# endif
+ } else {
+ GC_ADD_TO_BLACK_LIST_NORMAL(p, source);
+# undef source /* In case we had to define it. */
+ }
+ } else {
+ if (!mark_bit_from_hdr(hhdr, displ)) {
+ set_mark_bit_from_hdr(hhdr, displ);
+ PUSH_OBJ((word *)r, hhdr, GC_mark_stack_top,
+ &(GC_mark_stack[GC_mark_stack_size]));
+ }
+ }
+}
+
+# ifdef TRACE_BUF
+
+# define TRACE_ENTRIES 1000
+
+struct trace_entry {
+ char * kind;
+ word gc_no;
+ word words_allocd;
+ word arg1;
+ word arg2;
+} GC_trace_buf[TRACE_ENTRIES];
+
+int GC_trace_buf_ptr = 0;
+
+void GC_add_trace_entry(char *kind, word arg1, word arg2)
+{
+ GC_trace_buf[GC_trace_buf_ptr].kind = kind;
+ GC_trace_buf[GC_trace_buf_ptr].gc_no = GC_gc_no;
+ GC_trace_buf[GC_trace_buf_ptr].words_allocd = GC_words_allocd;
+ GC_trace_buf[GC_trace_buf_ptr].arg1 = arg1 ^ 0x80000000;
+ GC_trace_buf[GC_trace_buf_ptr].arg2 = arg2 ^ 0x80000000;
+ GC_trace_buf_ptr++;
+ if (GC_trace_buf_ptr >= TRACE_ENTRIES) GC_trace_buf_ptr = 0;
+}
+
+void GC_print_trace(word gc_no, GC_bool lock)
+{
+ int i;
+ struct trace_entry *p;
+
+ if (lock) LOCK();
+ for (i = GC_trace_buf_ptr-1; i != GC_trace_buf_ptr; i--) {
+ if (i < 0) i = TRACE_ENTRIES-1;
+ p = GC_trace_buf + i;
+ if (p -> gc_no < gc_no || p -> kind == 0) return;
+ printf("Trace:%s (gc:%d,words:%d) 0x%X, 0x%X\n",
+ p -> kind, p -> gc_no, p -> words_allocd,
+ (p -> arg1) ^ 0x80000000, (p -> arg2) ^ 0x80000000);
+ }
+ printf("Trace incomplete\n");
+ if (lock) UNLOCK();
+}
+
+# endif /* TRACE_BUF */
+
+/*
+ * A version of GC_push_all that treats all interior pointers as valid
+ */
+void GC_push_all_stack(bottom, top)
+ptr_t bottom;
+ptr_t top;
+{
+# ifdef ALL_INTERIOR_POINTERS
+ GC_push_all(bottom, top);
+# ifdef TRACE_BUF
+ GC_add_trace_entry("GC_push_all_stack", bottom, top);
+# endif
+# else
+ word * b = (word *)(((long) bottom + ALIGNMENT-1) & ~(ALIGNMENT-1));
+ word * t = (word *)(((long) top) & ~(ALIGNMENT-1));
+ register word *p;
+ register word q;
+ register word *lim;
+ register ptr_t greatest_ha = GC_greatest_plausible_heap_addr;
+ register ptr_t least_ha = GC_least_plausible_heap_addr;
+# define GC_greatest_plausible_heap_addr greatest_ha
+# define GC_least_plausible_heap_addr least_ha
+
+ if (top == 0) return;
+ /* check all pointers in range and put in push if they appear */
+ /* to be valid. */
+ lim = t - 1 /* longword */;
+ for (p = b; p <= lim; p = (word *)(((char *)p) + ALIGNMENT)) {
+ q = *p;
+ GC_PUSH_ONE_STACK(q);
+ }
+# undef GC_greatest_plausible_heap_addr
+# undef GC_least_plausible_heap_addr
+# endif
+}
+
+#ifndef SMALL_CONFIG
+/* Push all objects reachable from marked objects in the given block */
+/* of size 1 objects. */
+void GC_push_marked1(h, hhdr)
+struct hblk *h;
+register hdr * hhdr;
+{
+ word * mark_word_addr = &(hhdr->hb_marks[divWORDSZ(HDR_WORDS)]);
+ register word *p;
+ word *plim;
+ register int i;
+ register word q;
+ register word mark_word;
+ register ptr_t greatest_ha = GC_greatest_plausible_heap_addr;
+ register ptr_t least_ha = GC_least_plausible_heap_addr;
+# define GC_greatest_plausible_heap_addr greatest_ha
+# define GC_least_plausible_heap_addr least_ha
+
+ p = (word *)(h->hb_body);
+ plim = (word *)(((word)h) + HBLKSIZE);
+
+ /* go through all words in block */
+ while( p < plim ) {
+ mark_word = *mark_word_addr++;
+ i = 0;
+ while(mark_word != 0) {
+ if (mark_word & 1) {
+ q = p[i];
+ GC_PUSH_ONE_HEAP(q);
+ }
+ i++;
+ mark_word >>= 1;
+ }
+ p += WORDSZ;
+ }
+# undef GC_greatest_plausible_heap_addr
+# undef GC_least_plausible_heap_addr
+}
+
+
+#ifndef UNALIGNED
+
+/* Push all objects reachable from marked objects in the given block */
+/* of size 2 objects. */
+void GC_push_marked2(h, hhdr)
+struct hblk *h;
+register hdr * hhdr;
+{
+ word * mark_word_addr = &(hhdr->hb_marks[divWORDSZ(HDR_WORDS)]);
+ register word *p;
+ word *plim;
+ register int i;
+ register word q;
+ register word mark_word;
+ register ptr_t greatest_ha = GC_greatest_plausible_heap_addr;
+ register ptr_t least_ha = GC_least_plausible_heap_addr;
+# define GC_greatest_plausible_heap_addr greatest_ha
+# define GC_least_plausible_heap_addr least_ha
+
+ p = (word *)(h->hb_body);
+ plim = (word *)(((word)h) + HBLKSIZE);
+
+ /* go through all words in block */
+ while( p < plim ) {
+ mark_word = *mark_word_addr++;
+ i = 0;
+ while(mark_word != 0) {
+ if (mark_word & 1) {
+ q = p[i];
+ GC_PUSH_ONE_HEAP(q);
+ q = p[i+1];
+ GC_PUSH_ONE_HEAP(q);
+ }
+ i += 2;
+ mark_word >>= 2;
+ }
+ p += WORDSZ;
+ }
+# undef GC_greatest_plausible_heap_addr
+# undef GC_least_plausible_heap_addr
+}
+
+/* Push all objects reachable from marked objects in the given block */
+/* of size 4 objects. */
+/* There is a risk of mark stack overflow here. But we handle that. */
+/* And only unmarked objects get pushed, so it's not very likely. */
+void GC_push_marked4(h, hhdr)
+struct hblk *h;
+register hdr * hhdr;
+{
+ word * mark_word_addr = &(hhdr->hb_marks[divWORDSZ(HDR_WORDS)]);
+ register word *p;
+ word *plim;
+ register int i;
+ register word q;
+ register word mark_word;
+ register ptr_t greatest_ha = GC_greatest_plausible_heap_addr;
+ register ptr_t least_ha = GC_least_plausible_heap_addr;
+# define GC_greatest_plausible_heap_addr greatest_ha
+# define GC_least_plausible_heap_addr least_ha
+
+ p = (word *)(h->hb_body);
+ plim = (word *)(((word)h) + HBLKSIZE);
+
+ /* go through all words in block */
+ while( p < plim ) {
+ mark_word = *mark_word_addr++;
+ i = 0;
+ while(mark_word != 0) {
+ if (mark_word & 1) {
+ q = p[i];
+ GC_PUSH_ONE_HEAP(q);
+ q = p[i+1];
+ GC_PUSH_ONE_HEAP(q);
+ q = p[i+2];
+ GC_PUSH_ONE_HEAP(q);
+ q = p[i+3];
+ GC_PUSH_ONE_HEAP(q);
+ }
+ i += 4;
+ mark_word >>= 4;
+ }
+ p += WORDSZ;
+ }
+# undef GC_greatest_plausible_heap_addr
+# undef GC_least_plausible_heap_addr
+}
+
+#endif /* UNALIGNED */
+
+#endif /* SMALL_CONFIG */
+
+/* Push all objects reachable from marked objects in the given block */
+void GC_push_marked(h, hhdr)
+struct hblk *h;
+register hdr * hhdr;
+{
+ register int sz = hhdr -> hb_sz;
+ register word * p;
+ register int word_no;
+ register word * lim;
+ register mse * GC_mark_stack_top_reg;
+ register mse * mark_stack_limit = &(GC_mark_stack[GC_mark_stack_size]);
+
+ /* Some quick shortcuts: */
+ {
+ struct obj_kind *ok = &(GC_obj_kinds[hhdr -> hb_obj_kind]);
+ if ((0 | DS_LENGTH) == ok -> ok_descriptor
+ && FALSE == ok -> ok_relocate_descr)
+ return;
+ }
+ if (GC_block_empty(hhdr)/* nothing marked */) return;
+# ifdef GATHERSTATS
+ GC_n_rescuing_pages++;
+# endif
+ GC_objects_are_marked = TRUE;
+ if (sz > MAXOBJSZ) {
+ lim = (word *)(h + 1);
+ } else {
+ lim = (word *)(h + 1) - sz;
+ }
+
+ switch(sz) {
+# if !defined(SMALL_CONFIG)
+ case 1:
+ GC_push_marked1(h, hhdr);
+ break;
+# endif
+# if !defined(SMALL_CONFIG) && !defined(UNALIGNED)
+ case 2:
+ GC_push_marked2(h, hhdr);
+ break;
+ case 4:
+ GC_push_marked4(h, hhdr);
+ break;
+# endif
+ default:
+ GC_mark_stack_top_reg = GC_mark_stack_top;
+ for (p = (word *)h + HDR_WORDS, word_no = HDR_WORDS; p <= lim;
+ p += sz, word_no += sz) {
+ /* This ignores user specified mark procs. This currently */
+ /* doesn't matter, since marking from the whole object */
+ /* is always sufficient, and we will eventually use the user */
+ /* mark proc to avoid any bogus pointers. */
+ if (mark_bit_from_hdr(hhdr, word_no)) {
+ /* Mark from fields inside the object */
+ PUSH_OBJ((word *)p, hhdr, GC_mark_stack_top_reg, mark_stack_limit);
+# ifdef GATHERSTATS
+ /* Subtract this object from total, since it was */
+ /* added in twice. */
+ GC_composite_in_use -= sz;
+# endif
+ }
+ }
+ GC_mark_stack_top = GC_mark_stack_top_reg;
+ }
+}
+
+#ifndef SMALL_CONFIG
+/* Test whether any page in the given block is dirty */
+GC_bool GC_block_was_dirty(h, hhdr)
+struct hblk *h;
+register hdr * hhdr;
+{
+ register int sz = hhdr -> hb_sz;
+
+ if (sz < MAXOBJSZ) {
+ return(GC_page_was_dirty(h));
+ } else {
+ register ptr_t p = (ptr_t)h;
+ sz += HDR_WORDS;
+ sz = WORDS_TO_BYTES(sz);
+ while (p < (ptr_t)h + sz) {
+ if (GC_page_was_dirty((struct hblk *)p)) return(TRUE);
+ p += HBLKSIZE;
+ }
+ return(FALSE);
+ }
+}
+#endif /* SMALL_CONFIG */
+
+/* Similar to GC_push_next_marked, but return address of next block */
+struct hblk * GC_push_next_marked(h)
+struct hblk *h;
+{
+ register hdr * hhdr;
+
+ h = GC_next_block(h);
+ if (h == 0) return(0);
+ hhdr = HDR(h);
+ GC_push_marked(h, hhdr);
+ return(h + OBJ_SZ_TO_BLOCKS(hhdr -> hb_sz));
+}
+
+#ifndef SMALL_CONFIG
+/* Identical to above, but mark only from dirty pages */
+struct hblk * GC_push_next_marked_dirty(h)
+struct hblk *h;
+{
+ register hdr * hhdr = HDR(h);
+
+ if (!GC_dirty_maintained) { ABORT("dirty bits not set up"); }
+ for (;;) {
+ h = GC_next_block(h);
+ if (h == 0) return(0);
+ hhdr = HDR(h);
+# ifdef STUBBORN_ALLOC
+ if (hhdr -> hb_obj_kind == STUBBORN) {
+ if (GC_page_was_changed(h) && GC_block_was_dirty(h, hhdr)) {
+ break;
+ }
+ } else {
+ if (GC_block_was_dirty(h, hhdr)) break;
+ }
+# else
+ if (GC_block_was_dirty(h, hhdr)) break;
+# endif
+ h += OBJ_SZ_TO_BLOCKS(hhdr -> hb_sz);
+ }
+ GC_push_marked(h, hhdr);
+ return(h + OBJ_SZ_TO_BLOCKS(hhdr -> hb_sz));
+}
+#endif
+
+/* Similar to above, but for uncollectable pages. Needed since we */
+/* do not clear marks for such pages, even for full collections. */
+struct hblk * GC_push_next_marked_uncollectable(h)
+struct hblk *h;
+{
+ register hdr * hhdr = HDR(h);
+
+ for (;;) {
+ h = GC_next_block(h);
+ if (h == 0) return(0);
+ hhdr = HDR(h);
+ if (hhdr -> hb_obj_kind == UNCOLLECTABLE) break;
+ h += OBJ_SZ_TO_BLOCKS(hhdr -> hb_sz);
+ }
+ GC_push_marked(h, hhdr);
+ return(h + OBJ_SZ_TO_BLOCKS(hhdr -> hb_sz));
+}
+
+
projects / thirdparty / gcc.git / commitdiff
