Пример #1
0
/* Make sure the minor heap is empty by performing a minor collection
   if needed.
*/
void caml_empty_minor_heap (void)
{
    value **r;
    uintnat prev_alloc_words;

    if (caml_young_ptr != caml_young_end) {
        if (caml_minor_gc_begin_hook != NULL) (*caml_minor_gc_begin_hook) ();
        prev_alloc_words = caml_allocated_words;
        caml_in_minor_collection = 1;
        caml_gc_message (0x02, "<", 0);
        caml_oldify_local_roots();
        for (r = caml_ref_table.base; r < caml_ref_table.ptr; r++) {
            caml_oldify_one (**r, *r);
        }
        caml_oldify_mopup ();
        for (r = caml_weak_ref_table.base; r < caml_weak_ref_table.ptr; r++) {
            if (Is_block (**r) && Is_young (**r)) {
                if (Hd_val (**r) == 0) {
                    **r = Field (**r, 0);
                } else {
                    **r = caml_weak_none;
                }
            }
        }
        if (caml_young_ptr < caml_young_start) caml_young_ptr = caml_young_start;
        caml_stat_minor_words += Wsize_bsize (caml_young_end - caml_young_ptr);
        caml_young_ptr = caml_young_end;
        caml_young_limit = caml_young_start;
        clear_table (&caml_ref_table);
        clear_table (&caml_weak_ref_table);
        caml_gc_message (0x02, ">", 0);
        caml_in_minor_collection = 0;
        caml_stat_promoted_words += caml_allocated_words - prev_alloc_words;
        ++ caml_stat_minor_collections;
        caml_final_empty_young ();
        if (caml_minor_gc_end_hook != NULL) (*caml_minor_gc_end_hook) ();
    } else {
        caml_final_empty_young ();
    }
#ifdef DEBUG
    {
        value *p;
        for (p = (value *) caml_young_start; p < (value *) caml_young_end; ++p) {
            *p = Debug_free_minor;
        }
        ++ minor_gc_counter;
    }
#endif
}
Пример #2
0
void caml_empty_minor_heap_domain (struct domain* domain)
{
  CAMLnoalloc;
  caml_domain_state* domain_state = domain->state;
  struct caml_minor_tables *minor_tables = domain_state->minor_tables;
  unsigned rewrite_successes = 0;
  unsigned rewrite_failures = 0;
  char* young_ptr = domain_state->young_ptr;
  char* young_end = domain_state->young_end;
  uintnat minor_allocated_bytes = young_end - young_ptr;
  struct oldify_state st = {0};
  value **r;
  struct caml_ephe_ref_elt *re;
  struct caml_custom_elt *elt;

  st.promote_domain = domain;

  if (minor_allocated_bytes != 0) {
    uintnat prev_alloc_words = domain_state->allocated_words;

#ifdef DEBUG
    /* In DEBUG mode, verify that the minor_ref table contains all young-young pointers
       from older to younger objects */
    {
    struct addrmap young_young_ptrs = ADDRMAP_INIT;
    mlsize_t i;
    value iter;
    for (r = minor_tables->minor_ref.base; r < minor_tables->minor_ref.ptr; r++) {
      *caml_addrmap_insert_pos(&young_young_ptrs, (value)*r) = 1;
    }
    for (iter = (value)young_ptr;
         iter < (value)young_end;
         iter = next_minor_block(domain_state, iter)) {
      value hd = Hd_hp(iter);
      if (hd != 0) {
        value curr = Val_hp(iter);
        tag_t tag = Tag_hd (hd);

        if (tag < No_scan_tag && tag != Cont_tag) {
          // FIXME: should scan Cont_tag
          for (i = 0; i < Wosize_hd(hd); i++) {
            value* f = Op_val(curr) + i;
            if (Is_block(*f) && is_in_interval(*f, young_ptr, young_end) &&
                *f < curr) {
              CAMLassert(caml_addrmap_contains(&young_young_ptrs, (value)f));
            }
          }
        }
      }
    }
    caml_addrmap_clear(&young_young_ptrs);
    }
#endif

    caml_gc_log ("Minor collection of domain %d starting", domain->state->id);
    caml_ev_begin("minor_gc");
    caml_ev_begin("minor_gc/roots");
    caml_do_local_roots(&oldify_one, &st, domain, 0);

    caml_scan_stack(&oldify_one, &st, domain_state->current_stack);

    for (r = minor_tables->major_ref.base; r < minor_tables->major_ref.ptr; r++) {
      value x = **r;
      oldify_one (&st, x, &x);
    }
    caml_ev_end("minor_gc/roots");

    caml_ev_begin("minor_gc/promote");
    oldify_mopup (&st);
    caml_ev_end("minor_gc/promote");

    caml_ev_begin("minor_gc/ephemerons");
    for (re = minor_tables->ephe_ref.base;
         re < minor_tables->ephe_ref.ptr; re++) {
      CAMLassert (Ephe_domain(re->ephe) == domain);
      if (re->offset == CAML_EPHE_DATA_OFFSET) {
        /* Data field has already been handled in oldify_mopup. Handle only
         * keys here. */
        continue;
      }
      value* key = &Op_val(re->ephe)[re->offset];
      if (*key != caml_ephe_none && Is_block(*key) &&
          is_in_interval(*key, young_ptr, young_end)) {
        resolve_infix_val(key);
        if (Hd_val(*key) == 0) { /* value copied to major heap */
          *key = Op_val(*key)[0];
        } else {
          CAMLassert(!ephe_check_alive_data(re,young_ptr,young_end));
          *key = caml_ephe_none;
          Ephe_data(re->ephe) = caml_ephe_none;
        }
      }
    }
    caml_ev_end("minor_gc/ephemerons");

    caml_ev_begin("minor_gc/update_minor_tables");
    for (r = minor_tables->major_ref.base;
         r < minor_tables->major_ref.ptr; r++) {
      value v = **r;
      if (Is_block (v) && is_in_interval ((value)Hp_val(v), young_ptr, young_end)) {
        value vnew;
        header_t hd = Hd_val(v);
        int offset = 0;
        if (Tag_hd(hd) == Infix_tag) {
          offset = Infix_offset_hd(hd);
          v -= offset;
        }
        CAMLassert (Hd_val(v) == 0);
        vnew = Op_val(v)[0] + offset;
        CAMLassert (Is_block(vnew) && !Is_minor(vnew));
        CAMLassert (Hd_val(vnew));
        if (Tag_hd(hd) == Infix_tag) {
          CAMLassert(Tag_val(vnew) == Infix_tag);
          v += offset;
        }
        if (caml_domain_alone()) {
          **r = vnew;
          ++rewrite_successes;
        } else {
          if (atomic_compare_exchange_strong((atomic_value*)*r, &v, vnew))
            ++rewrite_successes;
          else
            ++rewrite_failures;
        }
      }
    }
    CAMLassert (!caml_domain_alone() || rewrite_failures == 0);
    caml_ev_end("minor_gc/update_minor_tables");

    caml_ev_begin("minor_gc/finalisers");
    caml_final_update_last_minor(domain);
    /* Run custom block finalisation of dead minor values */
    for (elt = minor_tables->custom.base; elt < minor_tables->custom.ptr; elt++) {
      value v = elt->block;
      if (Hd_val(v) == 0) {
        /* !!caml_adjust_gc_speed(elt->mem, elt->max); */
      } else {
        /* Block will be freed: call finalisation function, if any */
        void (*final_fun)(value) = Custom_ops_val(v)->finalize;
        if (final_fun != NULL) final_fun(v);
      }
    }
    caml_final_empty_young(domain);
    caml_ev_end("minor_gc/finalisers");


    clear_table ((struct generic_table *)&minor_tables->major_ref);
    clear_table ((struct generic_table *)&minor_tables->minor_ref);
    clear_table ((struct generic_table *)&minor_tables->ephe_ref);
    clear_table ((struct generic_table *)&minor_tables->custom);

    domain_state->young_ptr = domain_state->young_end;
    domain_state->stat_minor_words += Wsize_bsize (minor_allocated_bytes);
    domain_state->stat_minor_collections++;
    domain_state->stat_promoted_words += domain_state->allocated_words - prev_alloc_words;

    caml_ev_end("minor_gc");
    caml_gc_log ("Minor collection of domain %d completed: %2.0f%% of %u KB live, rewrite: successes=%u failures=%u",
                 domain->state->id,
                 100.0 * (double)st.live_bytes / (double)minor_allocated_bytes,
                 (unsigned)(minor_allocated_bytes + 512)/1024, rewrite_successes, rewrite_failures);
  }
  else {
    caml_final_empty_young(domain);
    caml_gc_log ("Minor collection of domain %d: skipping", domain->state->id);
  }

#ifdef DEBUG
  {
    value *p;
    for (p = (value *) domain_state->young_start;
         p < (value *) domain_state->young_end; ++p){
      *p = Debug_free_minor;
    }
  }
#endif
}