X-Git-Url: http://wien.tomnetworks.com/gitweb/?p=hs-boehmgc.git;a=blobdiff_plain;f=gc-7.2%2Freclaim.c;fp=gc-7.2%2Freclaim.c;h=44b4909b222f459a90ecfa6545e2f6fcc7190e82;hp=0000000000000000000000000000000000000000;hb=324587ba93dc77f37406d41fd2a20d0e0d94fb1d;hpb=2a4ea609491b225a1ceb06da70396e93916f137a

diff --git a/gc-7.2/reclaim.c b/gc-7.2/reclaim.c
new file mode 100644
index 0000000..44b4909
--- /dev/null
+++ b/gc-7.2/reclaim.c
@@ -0,0 +1,624 @@
+/*
+ * 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);
+}