diff options
Diffstat (limited to '')
| -rw-r--r-- | gc/mark.c | 862 |
1 files changed, 698 insertions, 164 deletions
@@ -2,6 +2,7 @@ /* * 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. @@ -16,8 +17,7 @@ # include <stdio.h> -# include "gc_priv.h" -# include "gc_mark.h" +# include "private/gc_pmark.h" /* We put this here to minimize the risk of inlining. */ /*VARARGS*/ @@ -38,7 +38,7 @@ word x; /* mark_proc GC_mark_procs[MAX_MARK_PROCS] = {0} -- declared in gc_priv.h */ -word GC_n_mark_procs = 0; +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 */ @@ -46,25 +46,21 @@ word GC_n_mark_procs = 0; /* 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 }, + 0 | GC_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 + 0 | GC_DS_LENGTH, /* Adjusted in GC_init_inner for EXTRA_BYTES */ TRUE /* add length to descr */, TRUE }, /* UNCOLLECTABLE */ { &GC_uobjfreelist[0], 0, - 0 | DS_LENGTH, TRUE /* add length to descr */, TRUE }, + 0 | GC_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 }, + 0 | GC_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 }, + 0 | GC_DS_LENGTH, TRUE /* add length to descr */, TRUE }, # endif }; @@ -87,6 +83,10 @@ struct obj_kind GC_obj_kinds[MAXOBJKINDS] = { # 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 /* @@ -100,9 +100,15 @@ word GC_n_rescuing_pages; /* Number of dirty pages we marked from */ mse * GC_mark_stack; +mse * GC_mark_stack_limit; + word GC_mark_stack_size = 0; -mse * GC_mark_stack_top; +#ifdef PARALLEL_MARK + mse * VOLATILE GC_mark_stack_top; +#else + mse * GC_mark_stack_top; +#endif static struct hblk * scan_ptr; @@ -125,7 +131,11 @@ GC_bool GC_collection_in_progress() void GC_clear_hdr_marks(hhdr) register hdr * hhdr; { - BZERO(hhdr -> hb_marks, MARK_BITS_SZ*sizeof(word)); +# 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. */ @@ -135,7 +145,11 @@ 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 } } @@ -143,9 +157,13 @@ register hdr * hhdr; * Clear all mark bits associated with block h. */ /*ARGSUSED*/ -static void clear_marks_for_block(h, dummy) -struct hblk *h; -word dummy; +# 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); @@ -223,9 +241,7 @@ void GC_initiate_gc() if (GC_dirty_maintained) GC_check_dirty(); } # endif -# ifdef GATHERSTATS - GC_n_rescuing_pages = 0; -# 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) { @@ -248,21 +264,38 @@ static void alloc_mark_stack(); GC_bool GC_mark_some(cold_gc_frame) ptr_t cold_gc_frame; { +#ifdef MSWIN32 + /* 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 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(); + >= 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 PRINTSTATS +# 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; @@ -275,8 +308,13 @@ ptr_t cold_gc_frame; case MS_PUSH_UNCOLLECTABLE: if (GC_mark_stack_top - >= GC_mark_stack + INITIAL_MARK_STACK_SIZE/4) { - GC_mark_from_mark_stack(); + >= 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); @@ -291,8 +329,32 @@ ptr_t cold_gc_frame; 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) { - GC_mark_from_mark_stack(); + MARK_FROM_MARK_STACK(); return(FALSE); } else { GC_mark_state = MS_NONE; @@ -309,7 +371,7 @@ ptr_t cold_gc_frame; return(FALSE); } if (GC_mark_stack_top >= GC_mark_stack) { - GC_mark_from_mark_stack(); + MARK_FROM_MARK_STACK(); return(FALSE); } if (scan_ptr == 0 && GC_mark_state == MS_INVALID) { @@ -333,6 +395,22 @@ ptr_t cold_gc_frame; ABORT("GC_mark_some: bad state"); return(FALSE); } +#ifdef MSWIN32 + } __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 /* MSWIN32 */ } @@ -349,27 +427,28 @@ GC_bool GC_mark_stack_empty() #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. */ +/* 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 - word GC_find_start(current, hhdr, source) - word source; + ptr_t GC_find_start(current, hhdr, new_hdr_p, source) + ptr_t source; # else - word GC_find_start(current, hhdr) + ptr_t GC_find_start(current, hhdr, new_hdr_p) # define source 0 # endif -register word current; -register hdr * hhdr; +register ptr_t current; +register hdr *hhdr, **new_hdr_p; { -# ifdef ALL_INTERIOR_POINTERS + if (GC_all_interior_pointers) { if (hhdr != 0) { - register word orig = current; + register ptr_t orig = current; - current = (word)HBLKPTR(current) + HDR_BYTES; + current = (ptr_t)HBLKPTR(current); do { current = current - HBLKSIZE*(word)hhdr; hhdr = HDR(current); @@ -379,18 +458,16 @@ register hdr * hhdr; 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(orig); } + *new_hdr_p = hhdr; return(current); } else { - GC_ADD_TO_BLACK_LIST_NORMAL(current, source); - return(0); + return(current); } -# else - GC_ADD_TO_BLACK_LIST_NORMAL(current, source); - return(0); -# endif + } else { + return(current); + } # undef source } @@ -405,14 +482,15 @@ mse * msp; { GC_mark_state = MS_INVALID; GC_mark_stack_too_small = TRUE; -# ifdef PRINTSTATS +# ifdef CONDPRINT + if (GC_print_stats) { GC_printf1("Mark stack overflow; current size = %lu entries\n", GC_mark_stack_size); -# endif - return(msp-INITIAL_MARK_STACK_SIZE/8); + } +# 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, @@ -420,12 +498,18 @@ mse * msp; * 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. */ -void GC_mark_from_mark_stack() +mse * GC_mark_from(mark_stack_top, mark_stack, mark_stack_limit) +mse * mark_stack_top; +mse * mark_stack; +mse * mark_stack_limit; { - 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. */ @@ -434,94 +518,509 @@ void GC_mark_from_mark_stack() 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 (GC_mark_stack_top_reg >= GC_mark_stack_reg && credit >= 0) { + while (mark_stack_top >= mark_stack && credit >= 0) { # else - while ((((ptr_t)GC_mark_stack_top_reg - (ptr_t)GC_mark_stack_reg) | credit) + while ((((ptr_t)mark_stack_top - (ptr_t)mark_stack) | credit) >= 0) { # endif - current_p = GC_mark_stack_top_reg -> mse_start; + current_p = mark_stack_top -> mse_start; + descr = mark_stack_top -> mse_descr; 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; + /* 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 DS_LENGTH: + case GC_DS_LENGTH: /* Large length. */ /* Process part of the range to avoid pushing too much on the */ /* stack. */ - GC_mark_stack_top_reg -> mse_start = +# 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); + GC_ASSERT(descr < GC_greatest_plausible_heap_addr + - GC_least_plausible_heap_addr); + 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; - GC_mark_stack_top_reg -> mse_descr -= - WORDS_TO_BYTES(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 DS_BITMAP: - GC_mark_stack_top_reg--; - descr &= ~DS_TAGS; + 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) { - PUSH_CONTENTS(current, GC_mark_stack_top_reg, mark_stack_limit, - current_p, exit1); + PREFETCH(current); + HC_PUSH_CONTENTS((ptr_t)current, mark_stack_top, + 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 = + case GC_DS_PROC: + mark_stack_top--; + credit -= GC_PROC_BYTES; + mark_stack_top = (*PROC(descr)) - (current_p, GC_mark_stack_top_reg, + (current_p, mark_stack_top, mark_stack_limit, ENV(descr)); continue; - case DS_PER_OBJECT: - GC_mark_stack_top_reg -> mse_descr = - *(word *)((ptr_t)current_p + descr - tag); + 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 { - GC_mark_stack_top_reg--; + } 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; - 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); + { +# 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); } - 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 } } - GC_mark_stack_top = GC_mark_stack_top_reg; + 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 ther 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 help 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()); + GC_ASSERT(!GC_help_wanted); + GC_ASSERT(GC_active_count == 0); +# 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 ms_entry)); + 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 ms_entry); + signed_word size = GC_mark_stack_size * sizeof(struct GC_ms_entry); /* Recycle old space */ if (0 != displ) displ = GC_page_size - displ; @@ -532,14 +1031,19 @@ word n; } GC_mark_stack = new_stack; GC_mark_stack_size = n; -# ifdef PRINTSTATS + 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 PRINTSTATS +# ifdef CONDPRINT + if (GC_print_stats) { GC_printf1("Failed to grow mark stack to %lu frames\n", (unsigned long) n); + } # endif } } else { @@ -549,6 +1053,7 @@ word n; } 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; } @@ -575,32 +1080,33 @@ ptr_t top; 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) { + if (GC_mark_stack_top >= GC_mark_stack_limit) { ABORT("unexpected mark stack overflow"); } length = top - bottom; -# if DS_TAGS > ALIGNMENT - 1 - length += DS_TAGS; - length &= ~DS_TAGS; +# 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 that may have been - * dirtied. A block h is assumed dirty if dirty_fn(h) != 0. + * 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_dirty(bottom, top, dirty_fn, push_fn) +void GC_push_selected(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 */); +int (*dirty_fn) GC_PROTO((struct hblk * h)); +void (*push_fn) GC_PROTO((ptr_t bottom, ptr_t top)); { register struct hblk * h; @@ -636,12 +1142,23 @@ void (*push_fn)(/* ptr_t bottom, ptr_t top */); (*push_fn)((ptr_t)h, top); } } - if (GC_mark_stack_top >= GC_mark_stack + GC_mark_stack_size) { + 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; @@ -651,7 +1168,7 @@ int 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); + GC_push_selected(bottom, top, GC_page_was_ever_dirty, GC_push_all); # else GC_push_all(bottom, top); # endif @@ -659,19 +1176,31 @@ int all; GC_push_all(bottom, top); } } else { - GC_push_dirty(bottom, top, GC_page_was_dirty, GC_push_all); + GC_push_selected(bottom, top, GC_page_was_dirty, GC_push_all); } } #endif -# ifdef MSWIN32 +# 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, 0); + 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__ @@ -680,16 +1209,21 @@ word p; # define BASE(p) (word)GC_base((char *)(p)) # endif -/* As above, but argument passed preliminary test. */ +/* 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_push_one_checked(p, interior_ptrs, source) + void GC_mark_and_push_stack(p, source) ptr_t source; # else - void GC_push_one_checked(p, interior_ptrs) + void GC_mark_and_push_stack(p) # define source 0 # endif register word p; -register GC_bool interior_ptrs; { register word r; register hdr * hhdr; @@ -697,31 +1231,25 @@ register GC_bool interior_ptrs; GET_HDR(p, hhdr); if (IS_FORWARDING_ADDR_OR_NIL(hhdr)) { - if (hhdr != 0 && interior_ptrs) { + if (hhdr != 0) { 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) { -# ifndef ALL_INTERIOR_POINTERS - if (interior_ptrs) { + 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 { + } else { + /* Offset invalid, but map reflects interior pointers */ hhdr = 0; - } -# else - /* map already reflects interior pointers */ - hhdr = 0; -# endif + } } else { displ = BYTES_TO_WORDS(displ); displ -= map_entry; @@ -731,22 +1259,18 @@ register GC_bool interior_ptrs; /* 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. */ - } +# 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[GC_mark_stack_size])); + GC_mark_stack_limit); } } } @@ -840,7 +1364,7 @@ ptr_t bottom; ptr_t top; ptr_t cold_gc_frame; { -# ifdef ALL_INTERIOR_POINTERS + 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. */ @@ -856,9 +1380,9 @@ ptr_t cold_gc_frame; GC_push_all_eager(cold_gc_frame, top); GC_push_all(bottom, cold_gc_frame + sizeof(ptr_t)); # endif /* STACK_GROWS_UP */ -# else + } else { GC_push_all_eager(bottom, top); -# endif + } # ifdef TRACE_BUF GC_add_trace_entry("GC_push_all_stack", bottom, top); # endif @@ -869,21 +1393,21 @@ void GC_push_all_stack(bottom, top) ptr_t bottom; ptr_t top; { -# ifdef ALL_INTERIOR_POINTERS + if (GC_all_interior_pointers) { GC_push_all(bottom, top); -# else + } else { GC_push_all_eager(bottom, top); -# endif + } } -#ifndef SMALL_CONFIG +#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[divWORDSZ(HDR_WORDS)]); + word * mark_word_addr = &(hhdr->hb_marks[0]); register word *p; word *plim; register int i; @@ -891,6 +1415,10 @@ register hdr * hhdr; 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 @@ -913,6 +1441,9 @@ register hdr * hhdr; } # 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; } @@ -924,7 +1455,7 @@ void GC_push_marked2(h, hhdr) struct hblk *h; register hdr * hhdr; { - word * mark_word_addr = &(hhdr->hb_marks[divWORDSZ(HDR_WORDS)]); + word * mark_word_addr = &(hhdr->hb_marks[0]); register word *p; word *plim; register int i; @@ -932,6 +1463,10 @@ register hdr * hhdr; 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 @@ -956,6 +1491,9 @@ register hdr * hhdr; } # 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 */ @@ -966,7 +1504,7 @@ void GC_push_marked4(h, hhdr) struct hblk *h; register hdr * hhdr; { - word * mark_word_addr = &(hhdr->hb_marks[divWORDSZ(HDR_WORDS)]); + word * mark_word_addr = &(hhdr->hb_marks[0]); register word *p; word *plim; register int i; @@ -974,6 +1512,10 @@ register hdr * hhdr; 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 @@ -1002,6 +1544,9 @@ register hdr * hhdr; } # 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 */ @@ -1014,37 +1559,32 @@ 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[GC_mark_stack_size]); + register mse * mark_stack_limit = GC_mark_stack_limit; /* 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 ((0 | GC_DS_LENGTH) == descr) return; if (GC_block_empty(hhdr)/* nothing marked */) return; -# ifdef GATHERSTATS - GC_n_rescuing_pages++; -# endif + GC_n_rescuing_pages++; GC_objects_are_marked = TRUE; if (sz > MAXOBJSZ) { - lim = (word *)(h + 1); + lim = (word *)h; } else { lim = (word *)(h + 1) - sz; } switch(sz) { -# if !defined(SMALL_CONFIG) +# if !defined(SMALL_CONFIG) && !defined(USE_MARK_BYTES) case 1: GC_push_marked1(h, hhdr); break; # endif -# if !defined(SMALL_CONFIG) && !defined(UNALIGNED) +# if !defined(SMALL_CONFIG) && !defined(UNALIGNED) && \ + !defined(USE_MARK_BYTES) case 2: GC_push_marked2(h, hhdr); break; @@ -1054,12 +1594,7 @@ register hdr * hhdr; # 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. */ + 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); @@ -1086,7 +1621,6 @@ register hdr * hhdr; 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); @@ -1115,7 +1649,7 @@ struct hblk *h; struct hblk * GC_push_next_marked_dirty(h) struct hblk *h; { - register hdr * hhdr = HDR(h); + register hdr * hhdr; if (!GC_dirty_maintained) { ABORT("dirty bits not set up"); } for (;;) { |