/*
* Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers
* Copyright (c) 1991-1994 by Xerox Corporation. All rights reserved.
- * Copyright (c) 1998 by Silicon Graphics. All rights reserved.
+ * Copyright (c) 1998-1999 by Silicon Graphics. All rights reserved.
+ * Copyright (c) 1999 by Hewlett-Packard Company. All rights reserved.
*
* THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
* OR IMPLIED. ANY USE IS AT YOUR OWN RISK.
* provided the above notices are retained, and a notice that the code was
* modified is included with the above copyright notice.
*/
-/* Boehm, August 9, 1995 5:08 pm PDT */
-#define DEBUG
-#undef DEBUG
+/* #define DEBUG */
#include <stdio.h>
-#include "gc_priv.h"
+#include "private/gc_priv.h"
+GC_bool GC_use_entire_heap = 0;
/*
- * allocate/free routines for heap blocks
- * Note that everything called from outside the garbage collector
- * should be prepared to abort at any point as the result of a signal.
+ * Free heap blocks are kept on one of several free lists,
+ * depending on the size of the block. Each free list is doubly linked.
+ * Adjacent free blocks are coalesced.
*/
-/*
- * Free heap blocks are kept on a list sorted by address.
- * The hb_hdr.hbh_sz field of a free heap block contains the length
- * (in bytes) of the entire block.
- * Neighbors are coalesced.
- */
# define MAX_BLACK_LIST_ALLOC (2*HBLKSIZE)
/* largest block we will allocate starting on a black */
/* listed block. Must be >= HBLKSIZE. */
-struct hblk * GC_hblkfreelist = 0;
-struct hblk *GC_savhbp = (struct hblk *)0; /* heap block preceding next */
- /* block to be examined by */
- /* GC_allochblk. */
+# define UNIQUE_THRESHOLD 32
+ /* Sizes up to this many HBLKs each have their own free list */
+# define HUGE_THRESHOLD 256
+ /* Sizes of at least this many heap blocks are mapped to a */
+ /* single free list. */
+# define FL_COMPRESSION 8
+ /* In between sizes map this many distinct sizes to a single */
+ /* bin. */
+
+# define N_HBLK_FLS (HUGE_THRESHOLD - UNIQUE_THRESHOLD)/FL_COMPRESSION \
+ + UNIQUE_THRESHOLD
+
+struct hblk * GC_hblkfreelist[N_HBLK_FLS+1] = { 0 };
+
+#ifndef USE_MUNMAP
+
+ word GC_free_bytes[N_HBLK_FLS+1] = { 0 };
+ /* Number of free bytes on each list. */
+
+ /* Is bytes + the number of free bytes on lists n .. N_HBLK_FLS */
+ /* > GC_max_large_allocd_bytes? */
+# ifdef __GNUC__
+ __inline__
+# endif
+ static GC_bool GC_enough_large_bytes_left(bytes,n)
+ word bytes;
+ int n;
+ {
+ int i;
+ for (i = N_HBLK_FLS; i >= n; --i) {
+ bytes += GC_free_bytes[i];
+ if (bytes > GC_max_large_allocd_bytes) return TRUE;
+ }
+ return FALSE;
+ }
+
+# define INCR_FREE_BYTES(n, b) GC_free_bytes[n] += (b);
+
+# define FREE_ASSERT(e) GC_ASSERT(e)
+
+#else /* USE_MUNMAP */
+
+# define INCR_FREE_BYTES(n, b)
+# define FREE_ASSERT(e)
+
+#endif /* USE_MUNMAP */
+
+/* Map a number of blocks to the appropriate large block free list index. */
+int GC_hblk_fl_from_blocks(blocks_needed)
+word blocks_needed;
+{
+ if (blocks_needed <= UNIQUE_THRESHOLD) return blocks_needed;
+ if (blocks_needed >= HUGE_THRESHOLD) return N_HBLK_FLS;
+ return (blocks_needed - UNIQUE_THRESHOLD)/FL_COMPRESSION
+ + UNIQUE_THRESHOLD;
+
+}
+
+# define PHDR(hhdr) HDR(hhdr -> hb_prev)
+# define NHDR(hhdr) HDR(hhdr -> hb_next)
+
+# ifdef USE_MUNMAP
+# define IS_MAPPED(hhdr) (((hhdr) -> hb_flags & WAS_UNMAPPED) == 0)
+# else /* !USE_MMAP */
+# define IS_MAPPED(hhdr) 1
+# endif /* USE_MUNMAP */
# if !defined(NO_DEBUGGING)
void GC_print_hblkfreelist()
{
- struct hblk * h = GC_hblkfreelist;
+ struct hblk * h;
word total_free = 0;
- hdr * hhdr = HDR(h);
+ hdr * hhdr;
word sz;
+ int i;
- while (h != 0) {
+ for (i = 0; i <= N_HBLK_FLS; ++i) {
+ h = GC_hblkfreelist[i];
+# ifdef USE_MUNMAP
+ if (0 != h) GC_printf1("Free list %ld:\n",
+ (unsigned long)i);
+# else
+ if (0 != h) GC_printf2("Free list %ld (Total size %ld):\n",
+ (unsigned long)i,
+ (unsigned long)GC_free_bytes[i]);
+# endif
+ while (h != 0) {
+ hhdr = HDR(h);
sz = hhdr -> hb_sz;
- GC_printf2("0x%lx size %lu ", (unsigned long)h, (unsigned long)sz);
+ GC_printf2("\t0x%lx size %lu ", (unsigned long)h, (unsigned long)sz);
total_free += sz;
if (GC_is_black_listed(h, HBLKSIZE) != 0) {
GC_printf0("start black listed\n");
GC_printf0("not black listed\n");
}
h = hhdr -> hb_next;
- hhdr = HDR(h);
+ }
}
+# ifndef USE_MUNMAP
+ if (total_free != GC_large_free_bytes) {
+ GC_printf1("GC_large_free_bytes = %lu (INCONSISTENT!!)\n",
+ (unsigned long) GC_large_free_bytes);
+ }
+# endif
GC_printf1("Total of %lu bytes on free list\n", (unsigned long)total_free);
}
+/* Return the free list index on which the block described by the header */
+/* appears, or -1 if it appears nowhere. */
+int free_list_index_of(wanted)
+hdr * wanted;
+{
+ struct hblk * h;
+ hdr * hhdr;
+ int i;
+
+ for (i = 0; i <= N_HBLK_FLS; ++i) {
+ h = GC_hblkfreelist[i];
+ while (h != 0) {
+ hhdr = HDR(h);
+ if (hhdr == wanted) return i;
+ h = hhdr -> hb_next;
+ }
+ }
+ return -1;
+}
+
+void GC_dump_regions()
+{
+ unsigned i;
+ ptr_t start, end;
+ ptr_t p;
+ size_t bytes;
+ hdr *hhdr;
+ for (i = 0; i < GC_n_heap_sects; ++i) {
+ start = GC_heap_sects[i].hs_start;
+ bytes = GC_heap_sects[i].hs_bytes;
+ end = start + bytes;
+ /* Merge in contiguous sections. */
+ while (i+1 < GC_n_heap_sects && GC_heap_sects[i+1].hs_start == end) {
+ ++i;
+ end = GC_heap_sects[i].hs_start + GC_heap_sects[i].hs_bytes;
+ }
+ GC_printf2("***Section from 0x%lx to 0x%lx\n", start, end);
+ for (p = start; p < end;) {
+ hhdr = HDR(p);
+ GC_printf1("\t0x%lx ", (unsigned long)p);
+ if (IS_FORWARDING_ADDR_OR_NIL(hhdr)) {
+ GC_printf1("Missing header!!(%ld)\n", hhdr);
+ p += HBLKSIZE;
+ continue;
+ }
+ if (HBLK_IS_FREE(hhdr)) {
+ int correct_index = GC_hblk_fl_from_blocks(
+ divHBLKSZ(hhdr -> hb_sz));
+ int actual_index;
+
+ GC_printf1("\tfree block of size 0x%lx bytes",
+ (unsigned long)(hhdr -> hb_sz));
+ if (IS_MAPPED(hhdr)) {
+ GC_printf0("\n");
+ } else {
+ GC_printf0("(unmapped)\n");
+ }
+ actual_index = free_list_index_of(hhdr);
+ if (-1 == actual_index) {
+ GC_printf1("\t\tBlock not on free list %ld!!\n",
+ correct_index);
+ } else if (correct_index != actual_index) {
+ GC_printf2("\t\tBlock on list %ld, should be on %ld!!\n",
+ actual_index, correct_index);
+ }
+ p += hhdr -> hb_sz;
+ } else {
+ GC_printf1("\tused for blocks of size 0x%lx bytes\n",
+ (unsigned long)WORDS_TO_BYTES(hhdr -> hb_sz));
+ p += HBLKSIZE * OBJ_SZ_TO_BLOCKS(hhdr -> hb_sz);
+ }
+ }
+ }
+}
+
# endif /* NO_DEBUGGING */
/* Initialize hdr for a block containing the indicated size and */
return(TRUE);
}
-#ifdef EXACT_FIRST
-# define LAST_TRIP 2
-#else
-# define LAST_TRIP 1
-#endif
+#define FL_UNKNOWN -1
+/*
+ * Remove hhdr from the appropriate free list.
+ * We assume it is on the nth free list, or on the size
+ * appropriate free list if n is FL_UNKNOWN.
+ */
+void GC_remove_from_fl(hhdr, n)
+hdr * hhdr;
+int n;
+{
+ int index;
+
+ GC_ASSERT(((hhdr -> hb_sz) & (HBLKSIZE-1)) == 0);
+# ifndef USE_MUNMAP
+ /* We always need index to mainatin free counts. */
+ if (FL_UNKNOWN == n) {
+ index = GC_hblk_fl_from_blocks(divHBLKSZ(hhdr -> hb_sz));
+ } else {
+ index = n;
+ }
+# endif
+ if (hhdr -> hb_prev == 0) {
+# ifdef USE_MUNMAP
+ if (FL_UNKNOWN == n) {
+ index = GC_hblk_fl_from_blocks(divHBLKSZ(hhdr -> hb_sz));
+ } else {
+ index = n;
+ }
+# endif
+ GC_ASSERT(HDR(GC_hblkfreelist[index]) == hhdr);
+ GC_hblkfreelist[index] = hhdr -> hb_next;
+ } else {
+ hdr *phdr;
+ GET_HDR(hhdr -> hb_prev, phdr);
+ phdr -> hb_next = hhdr -> hb_next;
+ }
+ INCR_FREE_BYTES(index, - (signed_word)(hhdr -> hb_sz));
+ FREE_ASSERT(GC_free_bytes[index] >= 0);
+ if (0 != hhdr -> hb_next) {
+ hdr * nhdr;
+ GC_ASSERT(!IS_FORWARDING_ADDR_OR_NIL(NHDR(hhdr)));
+ GET_HDR(hhdr -> hb_next, nhdr);
+ nhdr -> hb_prev = hhdr -> hb_prev;
+ }
+}
+
+/*
+ * Return a pointer to the free block ending just before h, if any.
+ */
+struct hblk * GC_free_block_ending_at(h)
+struct hblk *h;
+{
+ struct hblk * p = h - 1;
+ hdr * phdr;
+
+ GET_HDR(p, phdr);
+ while (0 != phdr && IS_FORWARDING_ADDR_OR_NIL(phdr)) {
+ p = FORWARDED_ADDR(p,phdr);
+ phdr = HDR(p);
+ }
+ if (0 != phdr) {
+ if(HBLK_IS_FREE(phdr)) {
+ return p;
+ } else {
+ return 0;
+ }
+ }
+ p = GC_prev_block(h - 1);
+ if (0 != p) {
+ phdr = HDR(p);
+ if (HBLK_IS_FREE(phdr) && (ptr_t)p + phdr -> hb_sz == (ptr_t)h) {
+ return p;
+ }
+ }
+ return 0;
+}
+
+/*
+ * Add hhdr to the appropriate free list.
+ * We maintain individual free lists sorted by address.
+ */
+void GC_add_to_fl(h, hhdr)
+struct hblk *h;
+hdr * hhdr;
+{
+ int index = GC_hblk_fl_from_blocks(divHBLKSZ(hhdr -> hb_sz));
+ struct hblk *second = GC_hblkfreelist[index];
+ hdr * second_hdr;
+# ifdef GC_ASSERTIONS
+ struct hblk *next = (struct hblk *)((word)h + hhdr -> hb_sz);
+ hdr * nexthdr = HDR(next);
+ struct hblk *prev = GC_free_block_ending_at(h);
+ hdr * prevhdr = HDR(prev);
+ GC_ASSERT(nexthdr == 0 || !HBLK_IS_FREE(nexthdr) || !IS_MAPPED(nexthdr));
+ GC_ASSERT(prev == 0 || !HBLK_IS_FREE(prevhdr) || !IS_MAPPED(prevhdr));
+# endif
+ GC_ASSERT(((hhdr -> hb_sz) & (HBLKSIZE-1)) == 0);
+ GC_hblkfreelist[index] = h;
+ INCR_FREE_BYTES(index, hhdr -> hb_sz);
+ FREE_ASSERT(GC_free_bytes[index] <= GC_large_free_bytes)
+ hhdr -> hb_next = second;
+ hhdr -> hb_prev = 0;
+ if (0 != second) {
+ GET_HDR(second, second_hdr);
+ second_hdr -> hb_prev = h;
+ }
+ GC_invalidate_map(hhdr);
+}
+
+#ifdef USE_MUNMAP
+
+/* Unmap blocks that haven't been recently touched. This is the only way */
+/* way blocks are ever unmapped. */
+void GC_unmap_old(void)
+{
+ struct hblk * h;
+ hdr * hhdr;
+ word sz;
+ unsigned short last_rec, threshold;
+ int i;
+# define UNMAP_THRESHOLD 6
+
+ for (i = 0; i <= N_HBLK_FLS; ++i) {
+ for (h = GC_hblkfreelist[i]; 0 != h; h = hhdr -> hb_next) {
+ hhdr = HDR(h);
+ if (!IS_MAPPED(hhdr)) continue;
+ threshold = (unsigned short)(GC_gc_no - UNMAP_THRESHOLD);
+ last_rec = hhdr -> hb_last_reclaimed;
+ if ((last_rec > GC_gc_no || last_rec < threshold)
+ && threshold < GC_gc_no /* not recently wrapped */) {
+ sz = hhdr -> hb_sz;
+ GC_unmap((ptr_t)h, sz);
+ hhdr -> hb_flags |= WAS_UNMAPPED;
+ }
+ }
+ }
+}
+
+/* Merge all unmapped blocks that are adjacent to other free */
+/* blocks. This may involve remapping, since all blocks are either */
+/* fully mapped or fully unmapped. */
+void GC_merge_unmapped(void)
+{
+ struct hblk * h, *next;
+ hdr * hhdr, *nexthdr;
+ word size, nextsize;
+ int i;
+
+ for (i = 0; i <= N_HBLK_FLS; ++i) {
+ h = GC_hblkfreelist[i];
+ while (h != 0) {
+ GET_HDR(h, hhdr);
+ size = hhdr->hb_sz;
+ next = (struct hblk *)((word)h + size);
+ GET_HDR(next, nexthdr);
+ /* Coalesce with successor, if possible */
+ if (0 != nexthdr && HBLK_IS_FREE(nexthdr)) {
+ nextsize = nexthdr -> hb_sz;
+ if (IS_MAPPED(hhdr)) {
+ GC_ASSERT(!IS_MAPPED(nexthdr));
+ /* make both consistent, so that we can merge */
+ if (size > nextsize) {
+ GC_remap((ptr_t)next, nextsize);
+ } else {
+ GC_unmap((ptr_t)h, size);
+ hhdr -> hb_flags |= WAS_UNMAPPED;
+ }
+ } else if (IS_MAPPED(nexthdr)) {
+ GC_ASSERT(!IS_MAPPED(hhdr));
+ if (size > nextsize) {
+ GC_unmap((ptr_t)next, nextsize);
+ } else {
+ GC_remap((ptr_t)h, size);
+ hhdr -> hb_flags &= ~WAS_UNMAPPED;
+ hhdr -> hb_last_reclaimed = nexthdr -> hb_last_reclaimed;
+ }
+ } else {
+ /* Unmap any gap in the middle */
+ GC_unmap_gap((ptr_t)h, size, (ptr_t)next, nexthdr -> hb_sz);
+ }
+ /* If they are both unmapped, we merge, but leave unmapped. */
+ GC_remove_from_fl(hhdr, i);
+ GC_remove_from_fl(nexthdr, FL_UNKNOWN);
+ hhdr -> hb_sz += nexthdr -> hb_sz;
+ GC_remove_header(next);
+ GC_add_to_fl(h, hhdr);
+ /* Start over at beginning of list */
+ h = GC_hblkfreelist[i];
+ } else /* not mergable with successor */ {
+ h = hhdr -> hb_next;
+ }
+ } /* while (h != 0) ... */
+ } /* for ... */
+}
+
+#endif /* USE_MUNMAP */
+
+/*
+ * Return a pointer to a block starting at h of length bytes.
+ * Memory for the block is mapped.
+ * Remove the block from its free list, and return the remainder (if any)
+ * to its appropriate free list.
+ * May fail by returning 0.
+ * The header for the returned block must be set up by the caller.
+ * If the return value is not 0, then hhdr is the header for it.
+ */
+struct hblk * GC_get_first_part(h, hhdr, bytes, index)
+struct hblk *h;
+hdr * hhdr;
+word bytes;
+int index;
+{
+ word total_size = hhdr -> hb_sz;
+ struct hblk * rest;
+ hdr * rest_hdr;
+
+ GC_ASSERT((total_size & (HBLKSIZE-1)) == 0);
+ GC_remove_from_fl(hhdr, index);
+ if (total_size == bytes) return h;
+ rest = (struct hblk *)((word)h + bytes);
+ rest_hdr = GC_install_header(rest);
+ if (0 == rest_hdr) {
+ /* This may be very bad news ... */
+ WARN("Header allocation failed: Dropping block.\n", 0);
+ return(0);
+ }
+ rest_hdr -> hb_sz = total_size - bytes;
+ rest_hdr -> hb_flags = 0;
+# ifdef GC_ASSERTIONS
+ /* Mark h not free, to avoid assertion about adjacent free blocks. */
+ hhdr -> hb_map = 0;
+# endif
+ GC_add_to_fl(rest, rest_hdr);
+ return h;
+}
+
+/*
+ * H is a free block. N points at an address inside it.
+ * A new header for n has already been set up. Fix up h's header
+ * to reflect the fact that it is being split, move it to the
+ * appropriate free list.
+ * N replaces h in the original free list.
+ *
+ * Nhdr is not completely filled in, since it is about to allocated.
+ * It may in fact end up on the wrong free list for its size.
+ * (Hence adding it to a free list is silly. But this path is hopefully
+ * rare enough that it doesn't matter. The code is cleaner this way.)
+ */
+void GC_split_block(h, hhdr, n, nhdr, index)
+struct hblk *h;
+hdr * hhdr;
+struct hblk *n;
+hdr * nhdr;
+int index; /* Index of free list */
+{
+ word total_size = hhdr -> hb_sz;
+ word h_size = (word)n - (word)h;
+ struct hblk *prev = hhdr -> hb_prev;
+ struct hblk *next = hhdr -> hb_next;
+
+ /* Replace h with n on its freelist */
+ nhdr -> hb_prev = prev;
+ nhdr -> hb_next = next;
+ nhdr -> hb_sz = total_size - h_size;
+ nhdr -> hb_flags = 0;
+ if (0 != prev) {
+ HDR(prev) -> hb_next = n;
+ } else {
+ GC_hblkfreelist[index] = n;
+ }
+ if (0 != next) {
+ HDR(next) -> hb_prev = n;
+ }
+ INCR_FREE_BYTES(index, -(signed_word)h_size);
+ FREE_ASSERT(GC_free_bytes[index] > 0);
+# ifdef GC_ASSERTIONS
+ nhdr -> hb_map = 0; /* Don't fail test for consecutive */
+ /* free blocks in GC_add_to_fl. */
+# endif
+# ifdef USE_MUNMAP
+ hhdr -> hb_last_reclaimed = GC_gc_no;
+# endif
+ hhdr -> hb_sz = h_size;
+ GC_add_to_fl(h, hhdr);
+ GC_invalidate_map(nhdr);
+}
+struct hblk * GC_allochblk_nth();
+
/*
* Allocate (and return pointer to) a heap block
- * for objects of size sz words.
+ * for objects of size sz words, searching the nth free list.
*
* NOTE: We set obj_map field in header correctly.
- * Caller is resposnsible for building an object freelist in block.
+ * Caller is responsible for building an object freelist in block.
*
- * We clear the block if it is destined for large objects, and if
- * kind requires that newly allocated objects be cleared.
+ * Unlike older versions of the collectors, the client is responsible
+ * for clearing the block, if necessary.
*/
struct hblk *
GC_allochblk(sz, kind, flags)
word sz;
int kind;
+unsigned flags; /* IGNORE_OFF_PAGE or 0 */
+{
+ word blocks = OBJ_SZ_TO_BLOCKS(sz);
+ int start_list = GC_hblk_fl_from_blocks(blocks);
+ int i;
+ for (i = start_list; i <= N_HBLK_FLS; ++i) {
+ struct hblk * result = GC_allochblk_nth(sz, kind, flags, i);
+ if (0 != result) {
+ return result;
+ }
+ }
+ return 0;
+}
+/*
+ * The same, but with search restricted to nth free list.
+ */
+struct hblk *
+GC_allochblk_nth(sz, kind, flags, n)
+word sz;
+int kind;
unsigned char flags; /* IGNORE_OFF_PAGE or 0 */
+int n;
{
- register struct hblk *thishbp;
- register hdr * thishdr; /* Header corr. to thishbp */
register struct hblk *hbp;
register hdr * hhdr; /* Header corr. to hbp */
- struct hblk *prevhbp;
- register hdr * phdr; /* Header corr. to prevhbp */
+ register struct hblk *thishbp;
+ register hdr * thishdr; /* Header corr. to hbp */
signed_word size_needed; /* number of bytes in requested objects */
signed_word size_avail; /* bytes available in this block */
- int trip_count = 0;
size_needed = HBLKSIZE * OBJ_SZ_TO_BLOCKS(sz);
/* search for a big enough block in free list */
- hbp = GC_savhbp;
- hhdr = HDR(hbp);
- for(;;) {
-
- prevhbp = hbp;
- phdr = hhdr;
- hbp = (prevhbp == 0? GC_hblkfreelist : phdr->hb_next);
- hhdr = HDR(hbp);
-
- if( prevhbp == GC_savhbp) {
- if (trip_count == LAST_TRIP) return(0);
- ++trip_count;
- }
-
- if( hbp == 0 ) continue;
-
+ hbp = GC_hblkfreelist[n];
+ for(; 0 != hbp; hbp = hhdr -> hb_next) {
+ GET_HDR(hbp, hhdr);
size_avail = hhdr->hb_sz;
-# ifdef EXACT_FIRST
- if (trip_count <= 1 && size_avail != size_needed) continue;
-# endif
if (size_avail < size_needed) continue;
-# ifdef PRESERVE_LAST
- if (size_avail != size_needed
- && !GC_incremental
- && GC_in_last_heap_sect(hbp) && GC_should_collect()) {
+ if (size_avail != size_needed
+ && !GC_use_entire_heap
+ && !GC_dont_gc
+ && USED_HEAP_SIZE >= GC_requested_heapsize
+ && !TRUE_INCREMENTAL && GC_should_collect()) {
+# ifdef USE_MUNMAP
continue;
- }
-# endif
+# else
+ /* If we have enough large blocks left to cover any */
+ /* previous request for large blocks, we go ahead */
+ /* and split. Assuming a steady state, that should */
+ /* be safe. It means that we can use the full */
+ /* heap if we allocate only small objects. */
+ if (!GC_enough_large_bytes_left(GC_large_allocd_bytes, n)) {
+ continue;
+ }
+ /* If we are deallocating lots of memory from */
+ /* finalizers, fail and collect sooner rather */
+ /* than later. */
+ if (WORDS_TO_BYTES(GC_finalizer_mem_freed)
+ > (GC_heapsize >> 4)) {
+ continue;
+ }
+# endif /* !USE_MUNMAP */
+ }
/* If the next heap block is obviously better, go on. */
/* This prevents us from disassembling a single large block */
/* to get tiny blocks. */
signed_word next_size;
thishbp = hhdr -> hb_next;
- if (thishbp == 0) thishbp = GC_hblkfreelist;
- thishdr = HDR(thishbp);
- next_size = (signed_word)(thishdr -> hb_sz);
- if (next_size < size_avail
+ if (thishbp != 0) {
+ GET_HDR(thishbp, thishdr);
+ next_size = (signed_word)(thishdr -> hb_sz);
+ if (next_size < size_avail
&& next_size >= size_needed
&& !GC_is_black_listed(thishbp, (word)size_needed)) {
continue;
+ }
}
}
if ( !IS_UNCOLLECTABLE(kind) &&
while ((ptr_t)lasthbp <= search_end
&& (thishbp = GC_is_black_listed(lasthbp,
- (word)eff_size_needed))) {
+ (word)eff_size_needed))
+ != 0) {
lasthbp = thishbp;
}
size_avail -= (ptr_t)lasthbp - (ptr_t)hbp;
thishbp = lasthbp;
if (size_avail >= size_needed) {
- if (thishbp != hbp && GC_install_header(thishbp)) {
+ if (thishbp != hbp &&
+ 0 != (thishdr = GC_install_header(thishbp))) {
+ /* Make sure it's mapped before we mangle it. */
+# ifdef USE_MUNMAP
+ if (!IS_MAPPED(hhdr)) {
+ GC_remap((ptr_t)hbp, hhdr -> hb_sz);
+ hhdr -> hb_flags &= ~WAS_UNMAPPED;
+ }
+# endif
/* Split the block at thishbp */
- thishdr = HDR(thishbp);
- /* GC_invalidate_map not needed, since we will */
- /* allocate this block. */
- thishdr -> hb_next = hhdr -> hb_next;
- thishdr -> hb_sz = size_avail;
- hhdr -> hb_sz = (ptr_t)thishbp - (ptr_t)hbp;
- hhdr -> hb_next = thishbp;
+ GC_split_block(hbp, hhdr, thishbp, thishdr, n);
/* Advance to thishbp */
- prevhbp = hbp;
- phdr = hhdr;
hbp = thishbp;
hhdr = thishdr;
+ /* We must now allocate thishbp, since it may */
+ /* be on the wrong free list. */
}
} else if (size_needed > (signed_word)BL_LIMIT
&& orig_avail - size_needed
> (signed_word)BL_LIMIT) {
/* Punt, since anything else risks unreasonable heap growth. */
- WARN("Needed to allocate blacklisted block at 0x%lx\n",
- (word)hbp);
- thishbp = hbp;
+ if (++GC_large_alloc_warn_suppressed
+ >= GC_large_alloc_warn_interval) {
+ WARN("Repeated allocation of very large block "
+ "(appr. size %ld):\n"
+ "\tMay lead to memory leak and poor performance.\n",
+ size_needed);
+ GC_large_alloc_warn_suppressed = 0;
+ }
size_avail = orig_avail;
- } else if (size_avail == 0
- && size_needed == HBLKSIZE
- && prevhbp != 0) {
-# ifndef FIND_LEAK
+ } else if (size_avail == 0 && size_needed == HBLKSIZE
+ && IS_MAPPED(hhdr)) {
+ if (!GC_find_leak) {
static unsigned count = 0;
/* The block is completely blacklisted. We need */
/* Allocate and drop the block in small chunks, to */
/* maximize the chance that we will recover some */
/* later. */
- struct hblk * limit = hbp + (hhdr->hb_sz/HBLKSIZE);
+ word total_size = hhdr -> hb_sz;
+ struct hblk * limit = hbp + divHBLKSZ(total_size);
struct hblk * h;
+ struct hblk * prev = hhdr -> hb_prev;
- GC_words_wasted += hhdr->hb_sz;
- phdr -> hb_next = hhdr -> hb_next;
+ GC_words_wasted += BYTES_TO_WORDS(total_size);
+ GC_large_free_bytes -= total_size;
+ GC_remove_from_fl(hhdr, n);
for (h = hbp; h < limit; h++) {
- if (h == hbp || GC_install_header(h)) {
- hhdr = HDR(h);
+ if (h == hbp || 0 != (hhdr = GC_install_header(h))) {
(void) setup_header(
hhdr,
- BYTES_TO_WORDS(HBLKSIZE - HDR_BYTES),
+ BYTES_TO_WORDS(HBLKSIZE),
PTRFREE, 0); /* Cant fail */
if (GC_debugging_started) {
- BZERO(hbp + HDR_BYTES, HBLKSIZE - HDR_BYTES);
+ BZERO(h, HBLKSIZE);
}
}
}
/* Restore hbp to point at free block */
- if (GC_savhbp == hbp) GC_savhbp = prevhbp;
- hbp = prevhbp;
- hhdr = phdr;
- if (hbp == GC_savhbp) --trip_count;
+ hbp = prev;
+ if (0 == hbp) {
+ return GC_allochblk_nth(sz, kind, flags, n);
+ }
+ hhdr = HDR(hbp);
}
-# endif
+ }
}
}
if( size_avail >= size_needed ) {
- /* found a big enough block */
- /* let thishbp --> the block */
- /* set prevhbp, hbp to bracket it */
- thishbp = hbp;
- thishdr = hhdr;
- if( size_avail == size_needed ) {
- hbp = hhdr->hb_next;
- hhdr = HDR(hbp);
- } else {
- hbp = (struct hblk *)
- (((word)thishbp) + size_needed);
- if (!GC_install_header(hbp)) {
- hbp = thishbp;
- continue;
- }
- hhdr = HDR(hbp);
- GC_invalidate_map(hhdr);
- hhdr->hb_next = thishdr->hb_next;
- hhdr->hb_sz = size_avail - size_needed;
- }
- /* remove *thishbp from hblk freelist */
- if( prevhbp == 0 ) {
- GC_hblkfreelist = hbp;
- } else {
- phdr->hb_next = hbp;
- }
- /* save current list search position */
- GC_savhbp = hbp;
+# ifdef USE_MUNMAP
+ if (!IS_MAPPED(hhdr)) {
+ GC_remap((ptr_t)hbp, hhdr -> hb_sz);
+ hhdr -> hb_flags &= ~WAS_UNMAPPED;
+ }
+# endif
+ /* hbp may be on the wrong freelist; the parameter n */
+ /* is important. */
+ hbp = GC_get_first_part(hbp, hhdr, size_needed, n);
break;
}
}
+
+ if (0 == hbp) return 0;
- /* Notify virtual dirty bit implementation that we are about to write. */
- GC_write_hint(thishbp);
-
/* Add it to map of valid blocks */
- if (!GC_install_counts(thishbp, (word)size_needed)) return(0);
+ if (!GC_install_counts(hbp, (word)size_needed)) return(0);
/* This leaks memory under very rare conditions. */
/* Set up header */
- if (!setup_header(thishdr, sz, kind, flags)) {
- GC_remove_counts(thishbp, (word)size_needed);
+ if (!setup_header(hhdr, sz, kind, flags)) {
+ GC_remove_counts(hbp, (word)size_needed);
return(0); /* ditto */
}
-
- /* Clear block if necessary */
- if (GC_debugging_started
- || sz > MAXOBJSZ && GC_obj_kinds[kind].ok_init) {
- BZERO(thishbp + HDR_BYTES, size_needed - HDR_BYTES);
- }
+ /* Notify virtual dirty bit implementation that we are about to write. */
+ /* Ensure that pointerfree objects are not protected if it's avoidable. */
+ GC_remove_protection(hbp, divHBLKSZ(size_needed),
+ (hhdr -> hb_descr == 0) /* pointer-free */);
+
/* We just successfully allocated a block. Restart count of */
/* consecutive failures. */
{
GC_fail_count = 0;
}
+
+ GC_large_free_bytes -= size_needed;
- return( thishbp );
+ GC_ASSERT(IS_MAPPED(hhdr));
+ return( hbp );
}
struct hblk * GC_freehblk_ptr = 0; /* Search position hint for GC_freehblk */
* All mark words are assumed to be cleared.
*/
void
-GC_freehblk(p)
-register struct hblk *p;
+GC_freehblk(hbp)
+struct hblk *hbp;
{
-register hdr *phdr; /* Header corresponding to p */
-register struct hblk *hbp, *prevhbp;
-register hdr *hhdr, *prevhdr;
-register signed_word size;
+struct hblk *next, *prev;
+hdr *hhdr, *prevhdr, *nexthdr;
+signed_word size;
- /* GC_savhbp may become invalid due to coalescing. Clear it. */
- GC_savhbp = (struct hblk *)0;
- phdr = HDR(p);
- size = phdr->hb_sz;
+ GET_HDR(hbp, hhdr);
+ size = hhdr->hb_sz;
size = HBLKSIZE * OBJ_SZ_TO_BLOCKS(size);
- GC_remove_counts(p, (word)size);
- phdr->hb_sz = size;
- GC_invalidate_map(phdr);
- prevhbp = 0;
-
- /* The following optimization was suggested by David Detlefs. */
- /* Note that the header cannot be NIL, since there cannot be an */
- /* intervening call to GC_freehblk without resetting */
- /* GC_freehblk_ptr. */
- if (GC_freehblk_ptr != 0 &&
- HDR(GC_freehblk_ptr)->hb_map == GC_invalid_map &&
- (ptr_t)GC_freehblk_ptr < (ptr_t)p) {
- hbp = GC_freehblk_ptr;
- } else {
- hbp = GC_hblkfreelist;
- };
- hhdr = HDR(hbp);
-
- while( (hbp != 0) && (hbp < p) ) {
- prevhbp = hbp;
- prevhdr = hhdr;
- hbp = hhdr->hb_next;
- hhdr = HDR(hbp);
- }
- GC_freehblk_ptr = prevhbp;
+ GC_remove_counts(hbp, (word)size);
+ hhdr->hb_sz = size;
+# ifdef USE_MUNMAP
+ hhdr -> hb_last_reclaimed = GC_gc_no;
+# endif
/* Check for duplicate deallocation in the easy case */
- if (hbp != 0 && (ptr_t)p + size > (ptr_t)hbp
- || prevhbp != 0 && (ptr_t)prevhbp + prevhdr->hb_sz > (ptr_t)p) {
+ if (HBLK_IS_FREE(hhdr)) {
GC_printf1("Duplicate large block deallocation of 0x%lx\n",
- (unsigned long) p);
- GC_printf2("Surrounding free blocks are 0x%lx and 0x%lx\n",
- (unsigned long) prevhbp, (unsigned long) hbp);
+ (unsigned long) hbp);
+ ABORT("Duplicate large block deallocation");
}
+ GC_ASSERT(IS_MAPPED(hhdr));
+ GC_invalidate_map(hhdr);
+ next = (struct hblk *)((word)hbp + size);
+ GET_HDR(next, nexthdr);
+ prev = GC_free_block_ending_at(hbp);
/* Coalesce with successor, if possible */
- if( (((word)p)+size) == ((word)hbp) ) {
- phdr->hb_next = hhdr->hb_next;
- phdr->hb_sz += hhdr->hb_sz;
- GC_remove_header(hbp);
- } else {
- phdr->hb_next = hbp;
+ if(0 != nexthdr && HBLK_IS_FREE(nexthdr) && IS_MAPPED(nexthdr)) {
+ GC_remove_from_fl(nexthdr, FL_UNKNOWN);
+ hhdr -> hb_sz += nexthdr -> hb_sz;
+ GC_remove_header(next);
+ }
+ /* Coalesce with predecessor, if possible. */
+ if (0 != prev) {
+ prevhdr = HDR(prev);
+ if (IS_MAPPED(prevhdr)) {
+ GC_remove_from_fl(prevhdr, FL_UNKNOWN);
+ prevhdr -> hb_sz += hhdr -> hb_sz;
+# ifdef USE_MUNMAP
+ prevhdr -> hb_last_reclaimed = GC_gc_no;
+# endif
+ GC_remove_header(hbp);
+ hbp = prev;
+ hhdr = prevhdr;
+ }
}
+ /* FIXME: It is not clear we really always want to do these merges */
+ /* with -DUSE_MUNMAP, since it updates ages and hence prevents */
+ /* unmapping. */
-
- if( prevhbp == 0 ) {
- GC_hblkfreelist = p;
- } else if( (((word)prevhbp) + prevhdr->hb_sz)
- == ((word)p) ) {
- /* Coalesce with predecessor */
- prevhdr->hb_next = phdr->hb_next;
- prevhdr->hb_sz += phdr->hb_sz;
- GC_remove_header(p);
- } else {
- prevhdr->hb_next = p;
- }
+ GC_large_free_bytes += size;
+ GC_add_to_fl(hbp, hhdr);
}
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