--- /dev/null
+/*
+ * Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers
+ * Copyright (c) 1991-1996 by Xerox Corporation. All rights reserved.
+ * Copyright (c) 1996-1999 by Silicon Graphics. All rights reserved.
+ * Copyright (c) 1999-2004 Hewlett-Packard Development Company, L.P.
+ *
+ * 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 "private/gc_priv.h"
+
+#include <stdio.h>
+
+GC_INNER signed_word GC_bytes_found = 0;
+ /* Number of bytes of memory reclaimed */
+ /* minus the number of bytes originally */
+ /* on free lists which we had to drop. */
+
+#if defined(PARALLEL_MARK)
+ GC_INNER word GC_fl_builder_count = 0;
+ /* Number of threads currently building free lists without */
+ /* holding GC lock. It is not safe to collect if this is */
+ /* nonzero. */
+#endif /* PARALLEL_MARK */
+
+/* We defer printing of leaked objects until we're done with the GC */
+/* cycle, since the routine for printing objects needs to run outside */
+/* the collector, e.g. without the allocation lock. */
+#ifndef MAX_LEAKED
+# define MAX_LEAKED 40
+#endif
+STATIC ptr_t GC_leaked[MAX_LEAKED] = { NULL };
+STATIC unsigned GC_n_leaked = 0;
+
+GC_INNER GC_bool GC_have_errors = FALSE;
+
+GC_INLINE void GC_add_leaked(ptr_t leaked)
+{
+# ifndef SHORT_DBG_HDRS
+ if (GC_findleak_delay_free && !GC_check_leaked(leaked))
+ return;
+# endif
+
+ GC_have_errors = TRUE;
+ /* FIXME: Prevent adding an object while printing leaked ones. */
+ if (GC_n_leaked < MAX_LEAKED) {
+ GC_leaked[GC_n_leaked++] = leaked;
+ /* Make sure it's not reclaimed this cycle */
+ GC_set_mark_bit(leaked);
+ }
+}
+
+/* Print all objects on the list after printing any smashed objects. */
+/* Clear both lists. Called without the allocation lock held. */
+GC_INNER void GC_print_all_errors(void)
+{
+ static GC_bool printing_errors = FALSE;
+ GC_bool have_errors;
+ unsigned i;
+ DCL_LOCK_STATE;
+
+ LOCK();
+ if (printing_errors) {
+ UNLOCK();
+ return;
+ }
+ have_errors = GC_have_errors;
+ printing_errors = TRUE;
+ UNLOCK();
+
+ if (GC_debugging_started) {
+ GC_print_all_smashed();
+ } else {
+ have_errors = FALSE;
+ }
+
+ for (i = 0; i < GC_n_leaked; ++i) {
+ ptr_t p = GC_leaked[i];
+ if (HDR(p) -> hb_obj_kind == PTRFREE) {
+ GC_err_printf("Leaked atomic object at ");
+ } else {
+ GC_err_printf("Leaked composite object at ");
+ }
+ GC_print_heap_obj(p);
+ GC_err_printf("\n");
+ GC_free(p);
+ GC_leaked[i] = 0;
+ have_errors = TRUE;
+ }
+ GC_n_leaked = 0;
+
+ if (have_errors
+# ifndef GC_ABORT_ON_LEAK
+ && GETENV("GC_ABORT_ON_LEAK") != NULL
+# endif
+ ) {
+ ABORT("Leaked or smashed objects encountered");
+ }
+
+ printing_errors = FALSE;
+}
+
+
+/*
+ * reclaim phase
+ *
+ */
+
+/* Test whether a block is completely empty, i.e. contains no marked */
+/* objects. This does not require the block to be in physical memory. */
+GC_INNER GC_bool GC_block_empty(hdr *hhdr)
+{
+ return (hhdr -> hb_n_marks == 0);
+}
+
+STATIC GC_bool GC_block_nearly_full(hdr *hhdr)
+{
+ return (hhdr -> hb_n_marks > 7 * HBLK_OBJS(hhdr -> hb_sz)/8);
+}
+
+/* FIXME: This should perhaps again be specialized for USE_MARK_BYTES */
+/* and USE_MARK_BITS cases. */
+
+/*
+ * Restore unmarked small objects in h of size sz to the object
+ * free list. Returns the new list.
+ * Clears unmarked objects. Sz is in bytes.
+ */
+STATIC ptr_t GC_reclaim_clear(struct hblk *hbp, hdr *hhdr, size_t sz,
+ ptr_t list, signed_word *count)
+{
+ word bit_no = 0;
+ word *p, *q, *plim;
+ signed_word n_bytes_found = 0;
+
+ GC_ASSERT(hhdr == GC_find_header((ptr_t)hbp));
+ GC_ASSERT(sz == hhdr -> hb_sz);
+ GC_ASSERT((sz & (BYTES_PER_WORD-1)) == 0);
+ p = (word *)(hbp->hb_body);
+ plim = (word *)(hbp->hb_body + HBLKSIZE - sz);
+
+ /* go through all words in block */
+ while (p <= plim) {
+ if( mark_bit_from_hdr(hhdr, bit_no) ) {
+ p = (word *)((ptr_t)p + sz);
+ } else {
+ n_bytes_found += sz;
+ /* object is available - put on list */
+ obj_link(p) = list;
+ list = ((ptr_t)p);
+ /* Clear object, advance p to next object in the process */
+ q = (word *)((ptr_t)p + sz);
+# ifdef USE_MARK_BYTES
+ GC_ASSERT(!(sz & 1)
+ && !((word)p & (2 * sizeof(word) - 1)));
+ p[1] = 0;
+ p += 2;
+ while (p < q) {
+ CLEAR_DOUBLE(p);
+ p += 2;
+ }
+# else
+ p++; /* Skip link field */
+ while (p < q) {
+ *p++ = 0;
+ }
+# endif
+ }
+ bit_no += MARK_BIT_OFFSET(sz);
+ }
+ *count += n_bytes_found;
+ return(list);
+}
+
+/* The same thing, but don't clear objects: */
+STATIC ptr_t GC_reclaim_uninit(struct hblk *hbp, hdr *hhdr, size_t sz,
+ ptr_t list, signed_word *count)
+{
+ word bit_no = 0;
+ word *p, *plim;
+ signed_word n_bytes_found = 0;
+
+ GC_ASSERT(sz == hhdr -> hb_sz);
+ p = (word *)(hbp->hb_body);
+ plim = (word *)((ptr_t)hbp + HBLKSIZE - sz);
+
+ /* go through all words in block */
+ while (p <= plim) {
+ if( !mark_bit_from_hdr(hhdr, bit_no) ) {
+ n_bytes_found += sz;
+ /* object is available - put on list */
+ obj_link(p) = list;
+ list = ((ptr_t)p);
+ }
+ p = (word *)((ptr_t)p + sz);
+ bit_no += MARK_BIT_OFFSET(sz);
+ }
+ *count += n_bytes_found;
+ return(list);
+}
+
+/* Don't really reclaim objects, just check for unmarked ones: */
+STATIC void GC_reclaim_check(struct hblk *hbp, hdr *hhdr, word sz)
+{
+ word bit_no;
+ ptr_t p, plim;
+ GC_ASSERT(sz == hhdr -> hb_sz);
+
+ /* go through all words in block */
+ p = hbp->hb_body;
+ plim = p + HBLKSIZE - sz;
+ for (bit_no = 0; p <= plim; p += sz, bit_no += MARK_BIT_OFFSET(sz)) {
+ if (!mark_bit_from_hdr(hhdr, bit_no)) {
+ GC_add_leaked(p);
+ }
+ }
+}
+
+/*
+ * Generic procedure to rebuild a free list in hbp.
+ * Also called directly from GC_malloc_many.
+ * Sz is now in bytes.
+ */
+GC_INNER ptr_t GC_reclaim_generic(struct hblk * hbp, hdr *hhdr, size_t sz,
+ GC_bool init, ptr_t list,
+ signed_word *count)
+{
+ ptr_t result;
+
+ GC_ASSERT(GC_find_header((ptr_t)hbp) == hhdr);
+# ifndef GC_DISABLE_INCREMENTAL
+ GC_remove_protection(hbp, 1, (hhdr)->hb_descr == 0 /* Pointer-free? */);
+# endif
+ if (init || GC_debugging_started) {
+ result = GC_reclaim_clear(hbp, hhdr, sz, list, count);
+ } else {
+ GC_ASSERT((hhdr)->hb_descr == 0 /* Pointer-free block */);
+ result = GC_reclaim_uninit(hbp, hhdr, sz, list, count);
+ }
+ if (IS_UNCOLLECTABLE(hhdr -> hb_obj_kind)) GC_set_hdr_marks(hhdr);
+ return result;
+}
+
+/*
+ * Restore unmarked small objects in the block pointed to by hbp
+ * to the appropriate object free list.
+ * If entirely empty blocks are to be completely deallocated, then
+ * caller should perform that check.
+ */
+STATIC void GC_reclaim_small_nonempty_block(struct hblk *hbp,
+ GC_bool report_if_found)
+{
+ hdr *hhdr = HDR(hbp);
+ size_t sz = hhdr -> hb_sz;
+ struct obj_kind * ok = &GC_obj_kinds[hhdr -> hb_obj_kind];
+ void **flh = &(ok -> ok_freelist[BYTES_TO_GRANULES(sz)]);
+
+ hhdr -> hb_last_reclaimed = (unsigned short) GC_gc_no;
+
+ if (report_if_found) {
+ GC_reclaim_check(hbp, hhdr, sz);
+ } else {
+ *flh = GC_reclaim_generic(hbp, hhdr, sz, ok -> ok_init,
+ *flh, &GC_bytes_found);
+ }
+}
+
+/*
+ * Restore an unmarked large object or an entirely empty blocks of small objects
+ * to the heap block free list.
+ * Otherwise enqueue the block for later processing
+ * by GC_reclaim_small_nonempty_block.
+ * If report_if_found is TRUE, then process any block immediately, and
+ * simply report free objects; do not actually reclaim them.
+ */
+STATIC void GC_reclaim_block(struct hblk *hbp, word report_if_found)
+{
+ hdr * hhdr = HDR(hbp);
+ size_t sz = hhdr -> hb_sz; /* size of objects in current block */
+ struct obj_kind * ok = &GC_obj_kinds[hhdr -> hb_obj_kind];
+ struct hblk ** rlh;
+
+ if( sz > MAXOBJBYTES ) { /* 1 big object */
+ if( !mark_bit_from_hdr(hhdr, 0) ) {
+ if (report_if_found) {
+ GC_add_leaked((ptr_t)hbp);
+ } else {
+ size_t blocks = OBJ_SZ_TO_BLOCKS(sz);
+ if (blocks > 1) {
+ GC_large_allocd_bytes -= blocks * HBLKSIZE;
+ }
+ GC_bytes_found += sz;
+ GC_freehblk(hbp);
+ }
+ } else {
+ if (hhdr -> hb_descr != 0) {
+ GC_composite_in_use += sz;
+ } else {
+ GC_atomic_in_use += sz;
+ }
+ }
+ } else {
+ GC_bool empty = GC_block_empty(hhdr);
+# ifdef PARALLEL_MARK
+ /* Count can be low or one too high because we sometimes */
+ /* have to ignore decrements. Objects can also potentially */
+ /* be repeatedly marked by each marker. */
+ /* Here we assume two markers, but this is extremely */
+ /* unlikely to fail spuriously with more. And if it does, it */
+ /* should be looked at. */
+ GC_ASSERT(hhdr -> hb_n_marks <= 2 * (HBLKSIZE/sz + 1) + 16);
+# else
+ GC_ASSERT(sz * hhdr -> hb_n_marks <= HBLKSIZE);
+# endif
+ if (hhdr -> hb_descr != 0) {
+ GC_composite_in_use += sz * hhdr -> hb_n_marks;
+ } else {
+ GC_atomic_in_use += sz * hhdr -> hb_n_marks;
+ }
+ if (report_if_found) {
+ GC_reclaim_small_nonempty_block(hbp, TRUE /* report_if_found */);
+ } else if (empty) {
+ GC_bytes_found += HBLKSIZE;
+ GC_freehblk(hbp);
+ } else if (GC_find_leak || !GC_block_nearly_full(hhdr)) {
+ /* group of smaller objects, enqueue the real work */
+ rlh = &(ok -> ok_reclaim_list[BYTES_TO_GRANULES(sz)]);
+ hhdr -> hb_next = *rlh;
+ *rlh = hbp;
+ } /* else not worth salvaging. */
+ /* We used to do the nearly_full check later, but we */
+ /* already have the right cache context here. Also */
+ /* doing it here avoids some silly lock contention in */
+ /* GC_malloc_many. */
+ }
+}
+
+#if !defined(NO_DEBUGGING)
+/* Routines to gather and print heap block info */
+/* intended for debugging. Otherwise should be called */
+/* with lock. */
+
+struct Print_stats
+{
+ size_t number_of_blocks;
+ size_t total_bytes;
+};
+
+#ifdef USE_MARK_BYTES
+
+/* Return the number of set mark bits in the given header. */
+/* Remains externally visible as used by GNU GCJ currently. */
+int GC_n_set_marks(hdr *hhdr)
+{
+ int result = 0;
+ int i;
+ size_t sz = hhdr -> hb_sz;
+ int offset = (int)MARK_BIT_OFFSET(sz);
+ int limit = (int)FINAL_MARK_BIT(sz);
+
+ for (i = 0; i < limit; i += offset) {
+ result += hhdr -> hb_marks[i];
+ }
+ GC_ASSERT(hhdr -> hb_marks[limit]);
+ return(result);
+}
+
+#else
+
+/* Number of set bits in a word. Not performance critical. */
+static int set_bits(word n)
+{
+ word m = n;
+ int result = 0;
+
+ while (m > 0) {
+ if (m & 1) result++;
+ m >>= 1;
+ }
+ return(result);
+}
+
+int GC_n_set_marks(hdr *hhdr)
+{
+ int result = 0;
+ int i;
+ int n_mark_words;
+# ifdef MARK_BIT_PER_OBJ
+ int n_objs = (int)HBLK_OBJS(hhdr -> hb_sz);
+
+ if (0 == n_objs) n_objs = 1;
+ n_mark_words = divWORDSZ(n_objs + WORDSZ - 1);
+# else /* MARK_BIT_PER_GRANULE */
+ n_mark_words = MARK_BITS_SZ;
+# endif
+ for (i = 0; i < n_mark_words - 1; i++) {
+ result += set_bits(hhdr -> hb_marks[i]);
+ }
+# ifdef MARK_BIT_PER_OBJ
+ result += set_bits((hhdr -> hb_marks[n_mark_words - 1])
+ << (n_mark_words * WORDSZ - n_objs));
+# else
+ result += set_bits(hhdr -> hb_marks[n_mark_words - 1]);
+# endif
+ return(result - 1);
+}
+
+#endif /* !USE_MARK_BYTES */
+
+STATIC void GC_print_block_descr(struct hblk *h,
+ word /* struct PrintStats */ raw_ps)
+{
+ hdr * hhdr = HDR(h);
+ size_t bytes = hhdr -> hb_sz;
+ struct Print_stats *ps;
+ unsigned n_marks = GC_n_set_marks(hhdr);
+
+ if (hhdr -> hb_n_marks != n_marks) {
+ GC_printf("(%u:%u,%u!=%u)", hhdr -> hb_obj_kind, (unsigned)bytes,
+ (unsigned)hhdr -> hb_n_marks, n_marks);
+ } else {
+ GC_printf("(%u:%u,%u)", hhdr -> hb_obj_kind,
+ (unsigned)bytes, n_marks);
+ }
+ bytes += HBLKSIZE-1;
+ bytes &= ~(HBLKSIZE-1);
+
+ ps = (struct Print_stats *)raw_ps;
+ ps->total_bytes += bytes;
+ ps->number_of_blocks++;
+}
+
+void GC_print_block_list(void)
+{
+ struct Print_stats pstats;
+
+ GC_printf("(kind(0=ptrfree,1=normal,2=unc.):size_in_bytes, #_marks_set)\n");
+ pstats.number_of_blocks = 0;
+ pstats.total_bytes = 0;
+ GC_apply_to_all_blocks(GC_print_block_descr, (word)&pstats);
+ GC_printf("\nblocks = %lu, bytes = %lu\n",
+ (unsigned long)pstats.number_of_blocks,
+ (unsigned long)pstats.total_bytes);
+}
+
+/* Currently for debugger use only: */
+void GC_print_free_list(int kind, size_t sz_in_granules)
+{
+ struct obj_kind * ok = &GC_obj_kinds[kind];
+ ptr_t flh = ok -> ok_freelist[sz_in_granules];
+ struct hblk *lastBlock = 0;
+ int n;
+
+ for (n = 1; flh; n++) {
+ struct hblk *block = HBLKPTR(flh);
+ if (block != lastBlock) {
+ GC_printf("\nIn heap block at %p:\n\t", block);
+ lastBlock = block;
+ }
+ GC_printf("%d: %p;", n, flh);
+ flh = obj_link(flh);
+ }
+}
+
+#endif /* !NO_DEBUGGING */
+
+/*
+ * Clear all obj_link pointers in the list of free objects *flp.
+ * Clear *flp.
+ * This must be done before dropping a list of free gcj-style objects,
+ * since may otherwise end up with dangling "descriptor" pointers.
+ * It may help for other pointer-containing objects.
+ */
+STATIC void GC_clear_fl_links(void **flp)
+{
+ void *next = *flp;
+
+ while (0 != next) {
+ *flp = 0;
+ flp = &(obj_link(next));
+ next = *flp;
+ }
+}
+
+/*
+ * Perform GC_reclaim_block on the entire heap, after first clearing
+ * small object free lists (if we are not just looking for leaks).
+ */
+GC_INNER void GC_start_reclaim(GC_bool report_if_found)
+{
+ unsigned kind;
+
+# if defined(PARALLEL_MARK)
+ GC_ASSERT(0 == GC_fl_builder_count);
+# endif
+ /* Reset in use counters. GC_reclaim_block recomputes them. */
+ GC_composite_in_use = 0;
+ GC_atomic_in_use = 0;
+ /* Clear reclaim- and free-lists */
+ for (kind = 0; kind < GC_n_kinds; kind++) {
+ void **fop;
+ void **lim;
+ struct hblk ** rlist = GC_obj_kinds[kind].ok_reclaim_list;
+ GC_bool should_clobber = (GC_obj_kinds[kind].ok_descriptor != 0);
+
+ if (rlist == 0) continue; /* This kind not used. */
+ if (!report_if_found) {
+ lim = &(GC_obj_kinds[kind].ok_freelist[MAXOBJGRANULES+1]);
+ for( fop = GC_obj_kinds[kind].ok_freelist; fop < lim; fop++ ) {
+ if (*fop != 0) {
+ if (should_clobber) {
+ GC_clear_fl_links(fop);
+ } else {
+ *fop = 0;
+ }
+ }
+ }
+ } /* otherwise free list objects are marked, */
+ /* and its safe to leave them */
+ BZERO(rlist, (MAXOBJGRANULES + 1) * sizeof(void *));
+ }
+
+
+ /* Go through all heap blocks (in hblklist) and reclaim unmarked objects */
+ /* or enqueue the block for later processing. */
+ GC_apply_to_all_blocks(GC_reclaim_block, (word)report_if_found);
+
+# ifdef EAGER_SWEEP
+ /* This is a very stupid thing to do. We make it possible anyway, */
+ /* so that you can convince yourself that it really is very stupid. */
+ GC_reclaim_all((GC_stop_func)0, FALSE);
+# endif
+# if defined(PARALLEL_MARK)
+ GC_ASSERT(0 == GC_fl_builder_count);
+# endif
+
+}
+
+/*
+ * Sweep blocks of the indicated object size and kind until either the
+ * appropriate free list is nonempty, or there are no more blocks to
+ * sweep.
+ */
+GC_INNER void GC_continue_reclaim(size_t sz /* granules */, int kind)
+{
+ hdr * hhdr;
+ struct hblk * hbp;
+ struct obj_kind * ok = &(GC_obj_kinds[kind]);
+ struct hblk ** rlh = ok -> ok_reclaim_list;
+ void **flh = &(ok -> ok_freelist[sz]);
+
+ if (rlh == 0) return; /* No blocks of this kind. */
+ rlh += sz;
+ while ((hbp = *rlh) != 0) {
+ hhdr = HDR(hbp);
+ *rlh = hhdr -> hb_next;
+ GC_reclaim_small_nonempty_block(hbp, FALSE);
+ if (*flh != 0) break;
+ }
+}
+
+/*
+ * Reclaim all small blocks waiting to be reclaimed.
+ * Abort and return FALSE when/if (*stop_func)() returns TRUE.
+ * If this returns TRUE, then it's safe to restart the world
+ * with incorrectly cleared mark bits.
+ * If ignore_old is TRUE, then reclaim only blocks that have been
+ * recently reclaimed, and discard the rest.
+ * Stop_func may be 0.
+ */
+GC_INNER GC_bool GC_reclaim_all(GC_stop_func stop_func, GC_bool ignore_old)
+{
+ word sz;
+ unsigned kind;
+ hdr * hhdr;
+ struct hblk * hbp;
+ struct obj_kind * ok;
+ struct hblk ** rlp;
+ struct hblk ** rlh;
+# ifndef SMALL_CONFIG
+ CLOCK_TYPE start_time = 0; /* initialized to prevent warning. */
+ CLOCK_TYPE done_time;
+
+ if (GC_print_stats == VERBOSE)
+ GET_TIME(start_time);
+# endif
+
+ for (kind = 0; kind < GC_n_kinds; kind++) {
+ ok = &(GC_obj_kinds[kind]);
+ rlp = ok -> ok_reclaim_list;
+ if (rlp == 0) continue;
+ for (sz = 1; sz <= MAXOBJGRANULES; sz++) {
+ rlh = rlp + sz;
+ while ((hbp = *rlh) != 0) {
+ if (stop_func != (GC_stop_func)0 && (*stop_func)()) {
+ return(FALSE);
+ }
+ hhdr = HDR(hbp);
+ *rlh = hhdr -> hb_next;
+ if (!ignore_old || hhdr -> hb_last_reclaimed == GC_gc_no - 1) {
+ /* It's likely we'll need it this time, too */
+ /* It's been touched recently, so this */
+ /* shouldn't trigger paging. */
+ GC_reclaim_small_nonempty_block(hbp, FALSE);
+ }
+ }
+ }
+ }
+# ifndef SMALL_CONFIG
+ if (GC_print_stats == VERBOSE) {
+ GET_TIME(done_time);
+ GC_log_printf("Disposing of reclaim lists took %lu msecs\n",
+ MS_TIME_DIFF(done_time,start_time));
+ }
+# endif
+ return(TRUE);
+}
projects / hs-boehmgc.git / blobdiff