+++ /dev/null
-
-/*
- * Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers
- * Copyright (c) 1991-1995 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.
- *
- */
-
-
-# include <stdio.h>
-# include "private/gc_pmark.h"
-
-/* We put this here to minimize the risk of inlining. */
-/*VARARGS*/
-#ifdef __WATCOMC__
- void GC_noop(void *p, ...) {}
-#else
- void GC_noop() {}
-#endif
-
-/* 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} -- declared in gc_priv.h */
-
-word GC_n_mark_procs = GC_RESERVED_MARK_PROCS;
-
-/* 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 | GC_DS_LENGTH, FALSE, FALSE },
-/* NORMAL */ { &GC_objfreelist[0], 0,
- 0 | GC_DS_LENGTH, /* Adjusted in GC_init_inner for EXTRA_BYTES */
- TRUE /* add length to descr */, TRUE },
-/* UNCOLLECTABLE */
- { &GC_uobjfreelist[0], 0,
- 0 | GC_DS_LENGTH, TRUE /* add length to descr */, TRUE },
-# ifdef ATOMIC_UNCOLLECTABLE
- /* AUNCOLLECTABLE */
- { &GC_auobjfreelist[0], 0,
- 0 | GC_DS_LENGTH, FALSE /* add length to descr */, FALSE },
-# endif
-# ifdef STUBBORN_ALLOC
-/*STUBBORN*/ { &GC_sobjfreelist[0], 0,
- 0 | GC_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. */
- /* The incremental collector actually likes a larger */
- /* size, since it want to push all marked dirty objs */
- /* before marking anything new. Currently we let it */
- /* grow dynamically. */
-# 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;
-
-mse * GC_mark_stack_limit;
-
-word GC_mark_stack_size = 0;
-
-#ifdef PARALLEL_MARK
- mse * VOLATILE GC_mark_stack_top;
-#else
- mse * GC_mark_stack_top;
-#endif
-
-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? */
-
-/* Is a collection in progress? Note that this can return true in the */
-/* nonincremental case, if a collection has been abandoned and the */
-/* mark state is now MS_INVALID. */
-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;
-{
-# ifdef USE_MARK_BYTES
- BZERO(hhdr -> hb_marks, MARK_BITS_SZ);
-# else
- BZERO(hhdr -> hb_marks, MARK_BITS_SZ*sizeof(word));
-# endif
-}
-
-/* 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) {
-# ifdef USE_MARK_BYTES
- hhdr -> hb_marks[i] = 1;
-# else
- hhdr -> hb_marks[i] = ONES;
-# endif
- }
-}
-
-/*
- * Clear all mark bits associated with block h.
- */
-/*ARGSUSED*/
-# if defined(__STDC__) || defined(__cplusplus)
- static void clear_marks_for_block(struct hblk *h, word dummy)
-# else
- static void clear_marks_for_block(h, dummy)
- struct hblk *h;
- word dummy;
-# endif
-{
- 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
- GC_n_rescuing_pages = 0;
- 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. */
-/* Cold_gc_frame is an address inside a GC frame that */
-/* remains valid until all marking is complete. */
-/* A zero value indicates that it's OK to miss some */
-/* register values. */
-GC_bool GC_mark_some(cold_gc_frame)
-ptr_t cold_gc_frame;
-{
-#if defined(MSWIN32) && !defined(__GNUC__)
- /* Windows 98 appears to asynchronously create and remove writable */
- /* memory mappings, for reasons we haven't yet understood. Since */
- /* we look for writable regions to determine the root set, we may */
- /* try to mark from an address range that disappeared since we */
- /* started the collection. Thus we have to recover from faults here. */
- /* This code does not appear to be necessary for Windows 95/NT/2000. */
- /* Note that this code should never generate an incremental GC write */
- /* fault. */
- __try {
-#endif /* defined(MSWIN32) && !defined(__GNUC__) */
- switch(GC_mark_state) {
- case MS_NONE:
- return(FALSE);
-
- case MS_PUSH_RESCUERS:
- if (GC_mark_stack_top
- >= GC_mark_stack_limit - INITIAL_MARK_STACK_SIZE/2) {
- /* Go ahead and mark, even though that might cause us to */
- /* see more marked dirty objects later on. Avoid this */
- /* in the future. */
- GC_mark_stack_too_small = TRUE;
- MARK_FROM_MARK_STACK();
- return(FALSE);
- } else {
- scan_ptr = GC_push_next_marked_dirty(scan_ptr);
- if (scan_ptr == 0) {
-# ifdef CONDPRINT
- if (GC_print_stats) {
- GC_printf1("Marked from %lu dirty pages\n",
- (unsigned long)GC_n_rescuing_pages);
- }
-# endif
- GC_push_roots(FALSE, cold_gc_frame);
- 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 + GC_mark_stack_size/4) {
-# ifdef PARALLEL_MARK
- /* Avoid this, since we don't parallelize the marker */
- /* here. */
- if (GC_parallel) GC_mark_stack_too_small = TRUE;
-# endif
- MARK_FROM_MARK_STACK();
- return(FALSE);
- } else {
- scan_ptr = GC_push_next_marked_uncollectable(scan_ptr);
- if (scan_ptr == 0) {
- GC_push_roots(TRUE, cold_gc_frame);
- GC_objects_are_marked = TRUE;
- if (GC_mark_state != MS_INVALID) {
- GC_mark_state = MS_ROOTS_PUSHED;
- }
- }
- }
- return(FALSE);
-
- case MS_ROOTS_PUSHED:
-# ifdef PARALLEL_MARK
- /* In the incremental GC case, this currently doesn't */
- /* quite do the right thing, since it runs to */
- /* completion. On the other hand, starting a */
- /* parallel marker is expensive, so perhaps it is */
- /* the right thing? */
- /* Eventually, incremental marking should run */
- /* asynchronously in multiple threads, without grabbing */
- /* the allocation lock. */
- if (GC_parallel) {
- GC_do_parallel_mark();
- GC_ASSERT(GC_mark_stack_top < GC_first_nonempty);
- GC_mark_stack_top = GC_mark_stack - 1;
- if (GC_mark_stack_too_small) {
- alloc_mark_stack(2*GC_mark_stack_size);
- }
- if (GC_mark_state == MS_ROOTS_PUSHED) {
- GC_mark_state = MS_NONE;
- return(TRUE);
- } else {
- return(FALSE);
- }
- }
-# endif
- if (GC_mark_stack_top >= GC_mark_stack) {
- 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) {
- MARK_FROM_MARK_STACK();
- return(FALSE);
- }
- if (scan_ptr == 0 && GC_mark_state == MS_INVALID) {
- /* About to start a heap scan for marked objects. */
- /* Mark stack is empty. OK to reallocate. */
- if (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, cold_gc_frame);
- 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);
- }
-#if defined(MSWIN32) && !defined(__GNUC__)
- } __except (GetExceptionCode() == EXCEPTION_ACCESS_VIOLATION ?
- EXCEPTION_EXECUTE_HANDLER : EXCEPTION_CONTINUE_SEARCH) {
-# ifdef CONDPRINT
- if (GC_print_stats) {
- GC_printf0("Caught ACCESS_VIOLATION in marker. "
- "Memory mapping disappeared.\n");
- }
-# endif /* CONDPRINT */
- /* We have bad roots on the stack. Discard mark stack. */
- /* Rescan from marked objects. Redetermine roots. */
- GC_invalidate_mark_state();
- scan_ptr = 0;
- return FALSE;
- }
-#endif /* defined(MSWIN32) && !defined(__GNUC__) */
-}
-
-
-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, either: */
-/* - return a pointer to somewhere in the first page of the large */
-/* object, if current points to a large object. */
-/* In this case *hhdr is replaced with a pointer to the header */
-/* for the large object. */
-/* - just return current if it does not point to a large object. */
-/*ARGSUSED*/
-# ifdef PRINT_BLACK_LIST
- ptr_t GC_find_start(current, hhdr, new_hdr_p, source)
- ptr_t source;
-# else
- ptr_t GC_find_start(current, hhdr, new_hdr_p)
-# define source 0
-# endif
-register ptr_t current;
-register hdr *hhdr, **new_hdr_p;
-{
- if (GC_all_interior_pointers) {
- if (hhdr != 0) {
- register ptr_t orig = current;
-
- current = (ptr_t)HBLKPTR(current);
- 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 */
- return(orig);
- }
- *new_hdr_p = hhdr;
- return(current);
- } else {
- return(current);
- }
- } else {
- return(current);
- }
-# 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;
- GC_mark_stack_too_small = TRUE;
-# ifdef CONDPRINT
- if (GC_print_stats) {
- GC_printf1("Mark stack overflow; current size = %lu entries\n",
- GC_mark_stack_size);
- }
-# endif
- return(msp - GC_MARK_STACK_DISCARDS);
-}
-
-/*
- * 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.
- * Note that this is the most performance critical routine in the
- * collector. Hence it contains all sorts of ugly hacks to speed
- * things up. In particular, we avoid procedure calls on the common
- * path, we take advantage of peculiarities of the mark descriptor
- * encoding, we optionally maintain a cache for the block address to
- * header mapping, we prefetch when an object is "grayed", etc.
- */
-mse * GC_mark_from(mark_stack_top, mark_stack, mark_stack_limit)
-mse * mark_stack_top;
-mse * mark_stack;
-mse * mark_stack_limit;
-{
- 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;
- DECLARE_HDR_CACHE;
-
-# define SPLIT_RANGE_WORDS 128 /* Must be power of 2. */
-
- GC_objects_are_marked = TRUE;
- INIT_HDR_CACHE;
-# ifdef OS2 /* Use untweaked version to circumvent compiler problem */
- while (mark_stack_top >= mark_stack && credit >= 0) {
-# else
- while ((((ptr_t)mark_stack_top - (ptr_t)mark_stack) | credit)
- >= 0) {
-# endif
- current_p = mark_stack_top -> mse_start;
- descr = mark_stack_top -> mse_descr;
- retry:
- /* current_p and descr describe the current object. */
- /* *mark_stack_top is vacant. */
- /* The following is 0 only for small objects described by a simple */
- /* length descriptor. For many applications this is the common */
- /* case, so we try to detect it quickly. */
- if (descr & ((~(WORDS_TO_BYTES(SPLIT_RANGE_WORDS) - 1)) | GC_DS_TAGS)) {
- word tag = descr & GC_DS_TAGS;
-
- switch(tag) {
- case GC_DS_LENGTH:
- /* Large length. */
- /* Process part of the range to avoid pushing too much on the */
- /* stack. */
- GC_ASSERT(descr < GC_greatest_plausible_heap_addr
- - GC_least_plausible_heap_addr);
-# ifdef PARALLEL_MARK
-# define SHARE_BYTES 2048
- if (descr > SHARE_BYTES && GC_parallel
- && mark_stack_top < mark_stack_limit - 1) {
- int new_size = (descr/2) & ~(sizeof(word)-1);
- mark_stack_top -> mse_start = current_p;
- mark_stack_top -> mse_descr = new_size + sizeof(word);
- /* makes sure we handle */
- /* misaligned pointers. */
- mark_stack_top++;
- current_p = (word *) ((char *)current_p + new_size);
- descr -= new_size;
- goto retry;
- }
-# endif /* PARALLEL_MARK */
- mark_stack_top -> mse_start =
- limit = current_p + SPLIT_RANGE_WORDS-1;
- mark_stack_top -> mse_descr =
- 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 GC_DS_BITMAP:
- mark_stack_top--;
- descr &= ~GC_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) {
- PREFETCH(current);
- HC_PUSH_CONTENTS((ptr_t)current, mark_stack_top,
- mark_stack_limit, current_p, exit1);
- }
- }
- descr <<= 1;
- ++ current_p;
- }
- continue;
- case GC_DS_PROC:
- mark_stack_top--;
- credit -= GC_PROC_BYTES;
- mark_stack_top =
- (*PROC(descr))
- (current_p, mark_stack_top,
- mark_stack_limit, ENV(descr));
- continue;
- case GC_DS_PER_OBJECT:
- if ((signed_word)descr >= 0) {
- /* Descriptor is in the object. */
- descr = *(word *)((ptr_t)current_p + descr - GC_DS_PER_OBJECT);
- } else {
- /* Descriptor is in type descriptor pointed to by first */
- /* word in object. */
- ptr_t type_descr = *(ptr_t *)current_p;
- /* type_descr is either a valid pointer to the descriptor */
- /* structure, or this object was on a free list. If it */
- /* it was anything but the last object on the free list, */
- /* we will misinterpret the next object on the free list as */
- /* the type descriptor, and get a 0 GC descriptor, which */
- /* is ideal. Unfortunately, we need to check for the last */
- /* object case explicitly. */
- if (0 == type_descr) {
- /* Rarely executed. */
- mark_stack_top--;
- continue;
- }
- descr = *(word *)(type_descr
- - (descr - (GC_DS_PER_OBJECT
- - GC_INDIR_PER_OBJ_BIAS)));
- }
- if (0 == descr) {
- /* Can happen either because we generated a 0 descriptor */
- /* or we saw a pointer to a free object. */
- mark_stack_top--;
- continue;
- }
- goto retry;
- }
- } else /* Small object with length descriptor */ {
- mark_stack_top--;
- limit = (word *)(((ptr_t)current_p) + (word)descr);
- }
- /* The simple case in which we're scanning a range. */
- GC_ASSERT(!((word)current_p & (ALIGNMENT-1)));
- credit -= (ptr_t)limit - (ptr_t)current_p;
- limit -= 1;
- {
-# define PREF_DIST 4
-
-# ifndef SMALL_CONFIG
- word deferred;
-
- /* Try to prefetch the next pointer to be examined asap. */
- /* Empirically, this also seems to help slightly without */
- /* prefetches, at least on linux/X86. Presumably this loop */
- /* ends up with less register pressure, and gcc thus ends up */
- /* generating slightly better code. Overall gcc code quality */
- /* for this loop is still not great. */
- for(;;) {
- PREFETCH((ptr_t)limit - PREF_DIST*CACHE_LINE_SIZE);
- GC_ASSERT(limit >= current_p);
- deferred = *limit;
- limit = (word *)((char *)limit - ALIGNMENT);
- if ((ptr_t)deferred >= least_ha && (ptr_t)deferred < greatest_ha) {
- PREFETCH(deferred);
- break;
- }
- if (current_p > limit) goto next_object;
- /* Unroll once, so we don't do too many of the prefetches */
- /* based on limit. */
- deferred = *limit;
- limit = (word *)((char *)limit - ALIGNMENT);
- if ((ptr_t)deferred >= least_ha && (ptr_t)deferred < greatest_ha) {
- PREFETCH(deferred);
- break;
- }
- if (current_p > limit) goto next_object;
- }
-# endif
-
- while (current_p <= limit) {
- /* Empirically, unrolling this loop doesn't help a lot. */
- /* Since HC_PUSH_CONTENTS expands to a lot of code, */
- /* we don't. */
- current = *current_p;
- PREFETCH((ptr_t)current_p + PREF_DIST*CACHE_LINE_SIZE);
- if ((ptr_t)current >= least_ha && (ptr_t)current < greatest_ha) {
- /* Prefetch the contents of the object we just pushed. It's */
- /* likely we will need them soon. */
- PREFETCH(current);
- HC_PUSH_CONTENTS((ptr_t)current, mark_stack_top,
- mark_stack_limit, current_p, exit2);
- }
- current_p = (word *)((char *)current_p + ALIGNMENT);
- }
-
-# ifndef SMALL_CONFIG
- /* We still need to mark the entry we previously prefetched. */
- /* We alrady know that it passes the preliminary pointer */
- /* validity test. */
- HC_PUSH_CONTENTS((ptr_t)deferred, mark_stack_top,
- mark_stack_limit, current_p, exit4);
- next_object:;
-# endif
- }
- }
- return mark_stack_top;
-}
-
-#ifdef PARALLEL_MARK
-
-/* We assume we have an ANSI C Compiler. */
-GC_bool GC_help_wanted = FALSE;
-unsigned GC_helper_count = 0;
-unsigned GC_active_count = 0;
-mse * VOLATILE GC_first_nonempty;
-word GC_mark_no = 0;
-
-#define LOCAL_MARK_STACK_SIZE HBLKSIZE
- /* Under normal circumstances, this is big enough to guarantee */
- /* We don't overflow half of it in a single call to */
- /* GC_mark_from. */
-
-
-/* Steal mark stack entries starting at mse low into mark stack local */
-/* until we either steal mse high, or we have max entries. */
-/* Return a pointer to the top of the local mark stack. */
-/* *next is replaced by a pointer to the next unscanned mark stack */
-/* entry. */
-mse * GC_steal_mark_stack(mse * low, mse * high, mse * local,
- unsigned max, mse **next)
-{
- mse *p;
- mse *top = local - 1;
- unsigned i = 0;
-
- GC_ASSERT(high >= low-1 && high - low + 1 <= GC_mark_stack_size);
- for (p = low; p <= high && i <= max; ++p) {
- word descr = *(volatile word *) &(p -> mse_descr);
- if (descr != 0) {
- *(volatile word *) &(p -> mse_descr) = 0;
- ++top;
- top -> mse_descr = descr;
- top -> mse_start = p -> mse_start;
- GC_ASSERT( top -> mse_descr & GC_DS_TAGS != GC_DS_LENGTH ||
- top -> mse_descr < GC_greatest_plausible_heap_addr
- - GC_least_plausible_heap_addr);
- /* There is no synchronization here. We assume that at */
- /* least one thread will see the original descriptor. */
- /* Otherwise we need a barrier. */
- /* More than one thread may get this entry, but that's only */
- /* a minor performance problem. */
- /* If this is a big object, count it as */
- /* size/256 + 1 objects. */
- ++i;
- if ((descr & GC_DS_TAGS) == GC_DS_LENGTH) i += (descr >> 8);
- }
- }
- *next = p;
- return top;
-}
-
-/* Copy back a local mark stack. */
-/* low and high are inclusive bounds. */
-void GC_return_mark_stack(mse * low, mse * high)
-{
- mse * my_top;
- mse * my_start;
- size_t stack_size;
-
- if (high < low) return;
- stack_size = high - low + 1;
- GC_acquire_mark_lock();
- my_top = GC_mark_stack_top;
- my_start = my_top + 1;
- if (my_start - GC_mark_stack + stack_size > GC_mark_stack_size) {
-# ifdef CONDPRINT
- if (GC_print_stats) {
- GC_printf0("No room to copy back mark stack.");
- }
-# endif
- GC_mark_state = MS_INVALID;
- GC_mark_stack_too_small = TRUE;
- /* We drop the local mark stack. We'll fix things later. */
- } else {
- BCOPY(low, my_start, stack_size * sizeof(mse));
- GC_ASSERT(GC_mark_stack_top = my_top);
-# if !defined(IA64) && !defined(HP_PA)
- GC_memory_write_barrier();
-# endif
- /* On IA64, the volatile write acts as a release barrier. */
- GC_mark_stack_top = my_top + stack_size;
- }
- GC_release_mark_lock();
- GC_notify_all_marker();
-}
-
-/* Mark from the local mark stack. */
-/* On return, the local mark stack is empty. */
-/* But this may be achieved by copying the */
-/* local mark stack back into the global one. */
-void GC_do_local_mark(mse *local_mark_stack, mse *local_top)
-{
- unsigned n;
-# define N_LOCAL_ITERS 1
-
-# ifdef GC_ASSERTIONS
- /* Make sure we don't hold mark lock. */
- GC_acquire_mark_lock();
- GC_release_mark_lock();
-# endif
- for (;;) {
- for (n = 0; n < N_LOCAL_ITERS; ++n) {
- local_top = GC_mark_from(local_top, local_mark_stack,
- local_mark_stack + LOCAL_MARK_STACK_SIZE);
- if (local_top < local_mark_stack) return;
- if (local_top - local_mark_stack >= LOCAL_MARK_STACK_SIZE/2) {
- GC_return_mark_stack(local_mark_stack, local_top);
- return;
- }
- }
- if (GC_mark_stack_top < GC_first_nonempty &&
- GC_active_count < GC_helper_count
- && local_top > local_mark_stack + 1) {
- /* Try to share the load, since the main stack is empty, */
- /* and helper threads are waiting for a refill. */
- /* The entries near the bottom of the stack are likely */
- /* to require more work. Thus we return those, eventhough */
- /* it's harder. */
- mse * p;
- mse * new_bottom = local_mark_stack
- + (local_top - local_mark_stack)/2;
- GC_ASSERT(new_bottom > local_mark_stack
- && new_bottom < local_top);
- GC_return_mark_stack(local_mark_stack, new_bottom - 1);
- memmove(local_mark_stack, new_bottom,
- (local_top - new_bottom + 1) * sizeof(mse));
- local_top -= (new_bottom - local_mark_stack);
- }
- }
-}
-
-#define ENTRIES_TO_GET 5
-
-long GC_markers = 2; /* Normally changed by thread-library- */
- /* -specific code. */
-
-/* Mark using the local mark stack until the global mark stack is empty */
-/* and there are no active workers. Update GC_first_nonempty to reflect */
-/* progress. */
-/* Caller does not hold mark lock. */
-/* Caller has already incremented GC_helper_count. We decrement it, */
-/* and maintain GC_active_count. */
-void GC_mark_local(mse *local_mark_stack, int id)
-{
- mse * my_first_nonempty;
-
- GC_acquire_mark_lock();
- GC_active_count++;
- my_first_nonempty = GC_first_nonempty;
- GC_ASSERT(GC_first_nonempty >= GC_mark_stack &&
- GC_first_nonempty <= GC_mark_stack_top + 1);
-# ifdef PRINTSTATS
- GC_printf1("Starting mark helper %lu\n", (unsigned long)id);
-# endif
- GC_release_mark_lock();
- for (;;) {
- size_t n_on_stack;
- size_t n_to_get;
- mse *next;
- mse * my_top;
- mse * local_top;
- mse * global_first_nonempty = GC_first_nonempty;
-
- GC_ASSERT(my_first_nonempty >= GC_mark_stack &&
- my_first_nonempty <= GC_mark_stack_top + 1);
- GC_ASSERT(global_first_nonempty >= GC_mark_stack &&
- global_first_nonempty <= GC_mark_stack_top + 1);
- if (my_first_nonempty < global_first_nonempty) {
- my_first_nonempty = global_first_nonempty;
- } else if (global_first_nonempty < my_first_nonempty) {
- GC_compare_and_exchange((word *)(&GC_first_nonempty),
- (word) global_first_nonempty,
- (word) my_first_nonempty);
- /* If this fails, we just go ahead, without updating */
- /* GC_first_nonempty. */
- }
- /* Perhaps we should also update GC_first_nonempty, if it */
- /* is less. But that would require using atomic updates. */
- my_top = GC_mark_stack_top;
- n_on_stack = my_top - my_first_nonempty + 1;
- if (0 == n_on_stack) {
- GC_acquire_mark_lock();
- my_top = GC_mark_stack_top;
- n_on_stack = my_top - my_first_nonempty + 1;
- if (0 == n_on_stack) {
- GC_active_count--;
- GC_ASSERT(GC_active_count <= GC_helper_count);
- /* Other markers may redeposit objects */
- /* on the stack. */
- if (0 == GC_active_count) GC_notify_all_marker();
- while (GC_active_count > 0
- && GC_first_nonempty > GC_mark_stack_top) {
- /* We will be notified if either GC_active_count */
- /* reaches zero, or if more objects are pushed on */
- /* the global mark stack. */
- GC_wait_marker();
- }
- if (GC_active_count == 0 &&
- GC_first_nonempty > GC_mark_stack_top) {
- GC_bool need_to_notify = FALSE;
- /* The above conditions can't be falsified while we */
- /* hold the mark lock, since neither */
- /* GC_active_count nor GC_mark_stack_top can */
- /* change. GC_first_nonempty can only be */
- /* incremented asynchronously. Thus we know that */
- /* both conditions actually held simultaneously. */
- GC_helper_count--;
- if (0 == GC_helper_count) need_to_notify = TRUE;
-# ifdef PRINTSTATS
- GC_printf1(
- "Finished mark helper %lu\n", (unsigned long)id);
-# endif
- GC_release_mark_lock();
- if (need_to_notify) GC_notify_all_marker();
- return;
- }
- /* else there's something on the stack again, or */
- /* another helper may push something. */
- GC_active_count++;
- GC_ASSERT(GC_active_count > 0);
- GC_release_mark_lock();
- continue;
- } else {
- GC_release_mark_lock();
- }
- }
- n_to_get = ENTRIES_TO_GET;
- if (n_on_stack < 2 * ENTRIES_TO_GET) n_to_get = 1;
- local_top = GC_steal_mark_stack(my_first_nonempty, my_top,
- local_mark_stack, n_to_get,
- &my_first_nonempty);
- GC_ASSERT(my_first_nonempty >= GC_mark_stack &&
- my_first_nonempty <= GC_mark_stack_top + 1);
- GC_do_local_mark(local_mark_stack, local_top);
- }
-}
-
-/* Perform Parallel mark. */
-/* We hold the GC lock, not the mark lock. */
-/* Currently runs until the mark stack is */
-/* empty. */
-void GC_do_parallel_mark()
-{
- mse local_mark_stack[LOCAL_MARK_STACK_SIZE];
- mse * local_top;
- mse * my_top;
-
- GC_acquire_mark_lock();
- GC_ASSERT(I_HOLD_LOCK());
- /* This could be a GC_ASSERT, but it seems safer to keep it on */
- /* all the time, especially since it's cheap. */
- if (GC_help_wanted || GC_active_count != 0 || GC_helper_count != 0)
- ABORT("Tried to start parallel mark in bad state");
-# ifdef PRINTSTATS
- GC_printf1("Starting marking for mark phase number %lu\n",
- (unsigned long)GC_mark_no);
-# endif
- GC_first_nonempty = GC_mark_stack;
- GC_active_count = 0;
- GC_helper_count = 1;
- GC_help_wanted = TRUE;
- GC_release_mark_lock();
- GC_notify_all_marker();
- /* Wake up potential helpers. */
- GC_mark_local(local_mark_stack, 0);
- GC_acquire_mark_lock();
- GC_help_wanted = FALSE;
- /* Done; clean up. */
- while (GC_helper_count > 0) GC_wait_marker();
- /* GC_helper_count cannot be incremented while GC_help_wanted == FALSE */
-# ifdef PRINTSTATS
- GC_printf1(
- "Finished marking for mark phase number %lu\n",
- (unsigned long)GC_mark_no);
-# endif
- GC_mark_no++;
- GC_release_mark_lock();
- GC_notify_all_marker();
-}
-
-
-/* Try to help out the marker, if it's running. */
-/* We do not hold the GC lock, but the requestor does. */
-void GC_help_marker(word my_mark_no)
-{
- mse local_mark_stack[LOCAL_MARK_STACK_SIZE];
- unsigned my_id;
- mse * my_first_nonempty;
-
- if (!GC_parallel) return;
- GC_acquire_mark_lock();
- while (GC_mark_no < my_mark_no
- || !GC_help_wanted && GC_mark_no == my_mark_no) {
- GC_wait_marker();
- }
- my_id = GC_helper_count;
- if (GC_mark_no != my_mark_no || my_id >= GC_markers) {
- /* Second test is useful only if original threads can also */
- /* act as helpers. Under Linux they can't. */
- GC_release_mark_lock();
- return;
- }
- GC_helper_count = my_id + 1;
- GC_release_mark_lock();
- GC_mark_local(local_mark_stack, my_id);
- /* GC_mark_local decrements GC_helper_count. */
-}
-
-#endif /* PARALLEL_MARK */
-
-/* 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 GC_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);
- signed_word size = GC_mark_stack_size * sizeof(struct GC_ms_entry);
-
- /* Recycle old space */
- if (0 != displ) displ = GC_page_size - displ;
- size = (size - displ) & ~(GC_page_size - 1);
- if (size > 0) {
- GC_add_to_heap((struct hblk *)
- ((word)GC_mark_stack + displ), (word)size);
- }
- GC_mark_stack = new_stack;
- GC_mark_stack_size = n;
- GC_mark_stack_limit = new_stack + n;
-# ifdef CONDPRINT
- if (GC_print_stats) {
- GC_printf1("Grew mark stack to %lu frames\n",
- (unsigned long) GC_mark_stack_size);
- }
-# endif
- } else {
-# ifdef CONDPRINT
- if (GC_print_stats) {
- 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_limit = new_stack + 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_limit) {
- ABORT("unexpected mark stack overflow");
- }
- length = top - bottom;
-# if GC_DS_TAGS > ALIGNMENT - 1
- length += GC_DS_TAGS;
- length &= ~GC_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 h with dirty_fn(h) != 0.
- * We use push_fn to actually push the block.
- * Used both to selectively push dirty pages, or to push a block
- * in piecemeal fashion, to allow for more marking concurrency.
- * 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_selected(bottom, top, dirty_fn, push_fn)
-ptr_t bottom;
-ptr_t top;
-int (*dirty_fn) GC_PROTO((struct hblk * h));
-void (*push_fn) GC_PROTO((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_limit) {
- ABORT("unexpected mark stack overflow");
- }
-}
-
-# ifndef SMALL_CONFIG
-
-#ifdef PARALLEL_MARK
- /* Break up root sections into page size chunks to better spread */
- /* out work. */
- GC_bool GC_true_func(struct hblk *h) { return TRUE; }
-# define GC_PUSH_ALL(b,t) GC_push_selected(b,t,GC_true_func,GC_push_all);
-#else
-# define GC_PUSH_ALL(b,t) GC_push_all(b,t);
-#endif
-
-
-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_selected(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_selected(bottom, top, GC_page_was_dirty, GC_push_all);
- }
-}
-#endif
-
-# if defined(MSWIN32) || defined(MSWINCE)
- void __cdecl GC_push_one(p)
-# else
- void GC_push_one(p)
-# endif
-word p;
-{
- GC_PUSH_ONE_STACK(p, MARKED_FROM_REGISTER);
-}
-
-struct GC_ms_entry *GC_mark_and_push(obj, mark_stack_ptr, mark_stack_limit, src)
-GC_PTR obj;
-struct GC_ms_entry * mark_stack_ptr;
-struct GC_ms_entry * mark_stack_limit;
-GC_PTR *src;
-{
- PREFETCH(obj);
- PUSH_CONTENTS(obj, mark_stack_ptr /* modified */, mark_stack_limit, src,
- was_marked /* internally generated exit label */);
- return mark_stack_ptr;
-}
-
-# ifdef __STDC__
-# define BASE(p) (word)GC_base((void *)(p))
-# else
-# define BASE(p) (word)GC_base((char *)(p))
-# endif
-
-/* Mark and push (i.e. gray) a single object p onto the main */
-/* mark stack. Consider p to be valid if it is an interior */
-/* pointer. */
-/* The object p has passed a preliminary pointer validity */
-/* test, but we do not definitely know whether it is valid. */
-/* Mark bits are NOT atomically updated. Thus this must be the */
-/* only thread setting them. */
-# if defined(PRINT_BLACK_LIST) || defined(KEEP_BACK_PTRS)
- void GC_mark_and_push_stack(p, source)
- ptr_t source;
-# else
- void GC_mark_and_push_stack(p)
-# define source 0
-# endif
-register word p;
-{
- register word r;
- register hdr * hhdr;
- register int displ;
-
- GET_HDR(p, hhdr);
- if (IS_FORWARDING_ADDR_OR_NIL(hhdr)) {
- if (hhdr != 0) {
- r = BASE(p);
- hhdr = HDR(r);
- displ = BYTES_TO_WORDS(HBLKDISPL(r));
- }
- } else {
- register map_entry_type map_entry;
-
- displ = HBLKDISPL(p);
- map_entry = MAP_ENTRY((hhdr -> hb_map), displ);
- if (map_entry >= MAX_OFFSET) {
- if (map_entry == OFFSET_TOO_BIG || !GC_all_interior_pointers) {
- r = BASE(p);
- displ = BYTES_TO_WORDS(HBLKDISPL(r));
- if (r == 0) hhdr = 0;
- } else {
- /* Offset invalid, but map reflects interior pointers */
- 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) {
-# ifdef PRINT_BLACK_LIST
- GC_add_to_black_list_stack(p, source);
-# else
- GC_add_to_black_list_stack(p);
-# endif
-# undef source /* In case we had to define it. */
- } else {
- if (!mark_bit_from_hdr(hhdr, displ)) {
- set_mark_bit_from_hdr(hhdr, displ);
- GC_STORE_BACK_PTR(source, (ptr_t)r);
- PUSH_OBJ((word *)r, hhdr, GC_mark_stack_top,
- GC_mark_stack_limit);
- }
- }
-}
-
-# 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
- * and scans the entire region immediately, in case the contents
- * change.
- */
-void GC_push_all_eager(bottom, top)
-ptr_t bottom;
-ptr_t top;
-{
- 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, p);
- }
-# undef GC_greatest_plausible_heap_addr
-# undef GC_least_plausible_heap_addr
-}
-
-#ifndef THREADS
-/*
- * A version of GC_push_all that treats all interior pointers as valid
- * and scans part of the area immediately, to make sure that saved
- * register values are not lost.
- * Cold_gc_frame delimits the stack section that must be scanned
- * eagerly. A zero value indicates that no eager scanning is needed.
- */
-void GC_push_all_stack_partially_eager(bottom, top, cold_gc_frame)
-ptr_t bottom;
-ptr_t top;
-ptr_t cold_gc_frame;
-{
- if (GC_all_interior_pointers) {
-# define EAGER_BYTES 1024
- /* Push the hot end of the stack eagerly, so that register values */
- /* saved inside GC frames are marked before they disappear. */
- /* The rest of the marking can be deferred until later. */
- if (0 == cold_gc_frame) {
- GC_push_all_stack(bottom, top);
- return;
- }
-# ifdef STACK_GROWS_DOWN
- GC_push_all(cold_gc_frame - sizeof(ptr_t), top);
- GC_push_all_eager(bottom, cold_gc_frame);
-# else /* STACK_GROWS_UP */
- GC_push_all(bottom, cold_gc_frame + sizeof(ptr_t));
- GC_push_all_eager(cold_gc_frame, top);
-# endif /* STACK_GROWS_UP */
- } else {
- GC_push_all_eager(bottom, top);
- }
-# ifdef TRACE_BUF
- GC_add_trace_entry("GC_push_all_stack", bottom, top);
-# endif
-}
-#endif /* !THREADS */
-
-void GC_push_all_stack(bottom, top)
-ptr_t bottom;
-ptr_t top;
-{
- if (GC_all_interior_pointers) {
- GC_push_all(bottom, top);
- } else {
- GC_push_all_eager(bottom, top);
- }
-}
-
-#if !defined(SMALL_CONFIG) && !defined(USE_MARK_BYTES)
-/* 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[0]);
- 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;
- register mse * mark_stack_top = GC_mark_stack_top;
- register mse * mark_stack_limit = GC_mark_stack_limit;
-# define GC_mark_stack_top mark_stack_top
-# define GC_mark_stack_limit mark_stack_limit
-# 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, p + i);
- }
- i++;
- mark_word >>= 1;
- }
- p += WORDSZ;
- }
-# undef GC_greatest_plausible_heap_addr
-# undef GC_least_plausible_heap_addr
-# undef GC_mark_stack_top
-# undef GC_mark_stack_limit
- GC_mark_stack_top = mark_stack_top;
-}
-
-
-#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[0]);
- 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;
- register mse * mark_stack_top = GC_mark_stack_top;
- register mse * mark_stack_limit = GC_mark_stack_limit;
-# define GC_mark_stack_top mark_stack_top
-# define GC_mark_stack_limit mark_stack_limit
-# 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, p + i);
- q = p[i+1];
- GC_PUSH_ONE_HEAP(q, p + i);
- }
- i += 2;
- mark_word >>= 2;
- }
- p += WORDSZ;
- }
-# undef GC_greatest_plausible_heap_addr
-# undef GC_least_plausible_heap_addr
-# undef GC_mark_stack_top
-# undef GC_mark_stack_limit
- GC_mark_stack_top = mark_stack_top;
-}
-
-/* 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[0]);
- 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;
- register mse * mark_stack_top = GC_mark_stack_top;
- register mse * mark_stack_limit = GC_mark_stack_limit;
-# define GC_mark_stack_top mark_stack_top
-# define GC_mark_stack_limit mark_stack_limit
-# 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, p + i);
- q = p[i+1];
- GC_PUSH_ONE_HEAP(q, p + i + 1);
- q = p[i+2];
- GC_PUSH_ONE_HEAP(q, p + i + 2);
- q = p[i+3];
- GC_PUSH_ONE_HEAP(q, p + i + 3);
- }
- i += 4;
- mark_word >>= 4;
- }
- p += WORDSZ;
- }
-# undef GC_greatest_plausible_heap_addr
-# undef GC_least_plausible_heap_addr
-# undef GC_mark_stack_top
-# undef GC_mark_stack_limit
- GC_mark_stack_top = mark_stack_top;
-}
-
-#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 int descr = hhdr -> hb_descr;
- 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_limit;
-
- /* Some quick shortcuts: */
- if ((0 | GC_DS_LENGTH) == descr) return;
- if (GC_block_empty(hhdr)/* nothing marked */) return;
- GC_n_rescuing_pages++;
- GC_objects_are_marked = TRUE;
- if (sz > MAXOBJSZ) {
- lim = (word *)h;
- } else {
- lim = (word *)(h + 1) - sz;
- }
-
- switch(sz) {
-# if !defined(SMALL_CONFIG) && !defined(USE_MARK_BYTES)
- case 1:
- GC_push_marked1(h, hhdr);
- break;
-# endif
-# if !defined(SMALL_CONFIG) && !defined(UNALIGNED) && \
- !defined(USE_MARK_BYTES)
- 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, word_no = 0; p <= lim; p += sz, word_no += sz) {
- 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 = 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_used_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;
-
- if (!GC_dirty_maintained) { ABORT("dirty bits not set up"); }
- for (;;) {
- h = GC_next_used_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_used_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 / msp430-gcc.git / blobdiff