hotspot/src/share/vm/gc_implementation/g1/g1CardCounts.cpp
changeset 26160 aba6b01cb988
parent 24424 2658d7834c6e
child 27149 9246fc481aa3
--- a/hotspot/src/share/vm/gc_implementation/g1/g1CardCounts.cpp	Mon Aug 18 19:30:24 2014 -0700
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1CardCounts.cpp	Tue Aug 19 14:09:10 2014 +0200
@@ -33,31 +33,26 @@
 
 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
 
+void G1CardCountsMappingChangedListener::on_commit(uint start_idx, size_t num_regions) {
+  MemRegion mr(G1CollectedHeap::heap()->bottom_addr_for_region(start_idx), num_regions * HeapRegion::GrainWords);
+  _counts->clear_range(mr);
+}
+
 void G1CardCounts::clear_range(size_t from_card_num, size_t to_card_num) {
   if (has_count_table()) {
-    assert(from_card_num >= 0 && from_card_num < _committed_max_card_num,
-           err_msg("from card num out of range: "SIZE_FORMAT, from_card_num));
     assert(from_card_num < to_card_num,
            err_msg("Wrong order? from: " SIZE_FORMAT ", to: "SIZE_FORMAT,
                    from_card_num, to_card_num));
-    assert(to_card_num <= _committed_max_card_num,
-           err_msg("to card num out of range: "
-                   "to: "SIZE_FORMAT ", "
-                   "max: "SIZE_FORMAT,
-                   to_card_num, _committed_max_card_num));
-
-    to_card_num = MIN2(_committed_max_card_num, to_card_num);
-
     Copy::fill_to_bytes(&_card_counts[from_card_num], (to_card_num - from_card_num));
   }
 }
 
 G1CardCounts::G1CardCounts(G1CollectedHeap *g1h):
-  _g1h(g1h), _card_counts(NULL),
-  _reserved_max_card_num(0), _committed_max_card_num(0),
-  _committed_size(0) {}
+  _listener(), _g1h(g1h), _card_counts(NULL), _reserved_max_card_num(0) {
+  _listener.set_cardcounts(this);
+}
 
-void G1CardCounts::initialize() {
+void G1CardCounts::initialize(G1RegionToSpaceMapper* mapper) {
   assert(_g1h->max_capacity() > 0, "initialization order");
   assert(_g1h->capacity() == 0, "initialization order");
 
@@ -70,70 +65,9 @@
     _ct_bs = _g1h->g1_barrier_set();
     _ct_bot = _ct_bs->byte_for_const(_g1h->reserved_region().start());
 
-    // Allocate/Reserve the counts table
-    size_t reserved_bytes = _g1h->max_capacity();
-    _reserved_max_card_num = reserved_bytes >> CardTableModRefBS::card_shift;
-
-    size_t reserved_size = _reserved_max_card_num * sizeof(jbyte);
-    ReservedSpace rs(ReservedSpace::allocation_align_size_up(reserved_size));
-    if (!rs.is_reserved()) {
-      warning("Could not reserve enough space for the card counts table");
-      guarantee(!has_reserved_count_table(), "should be NULL");
-      return;
-    }
-
-    MemTracker::record_virtual_memory_type((address)rs.base(), mtGC);
-
-    _card_counts_storage.initialize(rs, 0);
-    _card_counts = (jubyte*) _card_counts_storage.low();
-  }
-}
-
-void G1CardCounts::resize(size_t heap_capacity) {
-  // Expand the card counts table to handle a heap with the given capacity.
-
-  if (!has_reserved_count_table()) {
-    // Don't expand if we failed to reserve the card counts table.
-    return;
-  }
-
-  assert(_committed_size ==
-         ReservedSpace::allocation_align_size_up(_committed_size),
-         err_msg("Unaligned? committed_size: " SIZE_FORMAT, _committed_size));
-
-  // Verify that the committed space for the card counts matches our
-  // committed max card num. Note for some allocation alignments, the
-  // amount of space actually committed for the counts table will be able
-  // to span more cards than the number spanned by the maximum heap.
-  size_t prev_committed_size = _committed_size;
-  size_t prev_committed_card_num = committed_to_card_num(prev_committed_size);
-
-  assert(prev_committed_card_num == _committed_max_card_num,
-         err_msg("Card mismatch: "
-                 "prev: " SIZE_FORMAT ", "
-                 "committed: "SIZE_FORMAT", "
-                 "reserved: "SIZE_FORMAT,
-                 prev_committed_card_num, _committed_max_card_num, _reserved_max_card_num));
-
-  size_t new_size = (heap_capacity >> CardTableModRefBS::card_shift) * sizeof(jbyte);
-  size_t new_committed_size = ReservedSpace::allocation_align_size_up(new_size);
-  size_t new_committed_card_num = committed_to_card_num(new_committed_size);
-
-  if (_committed_max_card_num < new_committed_card_num) {
-    // we need to expand the backing store for the card counts
-    size_t expand_size = new_committed_size - prev_committed_size;
-
-    if (!_card_counts_storage.expand_by(expand_size)) {
-      warning("Card counts table backing store commit failure");
-      return;
-    }
-    assert(_card_counts_storage.committed_size() == new_committed_size,
-           "expansion commit failure");
-
-    _committed_size = new_committed_size;
-    _committed_max_card_num = new_committed_card_num;
-
-    clear_range(prev_committed_card_num, _committed_max_card_num);
+    _card_counts = (jubyte*) mapper->reserved().start();
+    _reserved_max_card_num = mapper->reserved().byte_size();
+    mapper->set_mapping_changed_listener(&_listener);
   }
 }
 
@@ -149,12 +83,13 @@
   uint count = 0;
   if (has_count_table()) {
     size_t card_num = ptr_2_card_num(card_ptr);
-    if (card_num < _committed_max_card_num) {
-      count = (uint) _card_counts[card_num];
-      if (count < G1ConcRSHotCardLimit) {
-        _card_counts[card_num] =
-          (jubyte)(MIN2((uintx)(_card_counts[card_num] + 1), G1ConcRSHotCardLimit));
-      }
+    assert(card_num < _reserved_max_card_num,
+           err_msg("Card "SIZE_FORMAT" outside of card counts table (max size "SIZE_FORMAT")",
+                   card_num, _reserved_max_card_num));
+    count = (uint) _card_counts[card_num];
+    if (count < G1ConcRSHotCardLimit) {
+      _card_counts[card_num] =
+        (jubyte)(MIN2((uintx)(_card_counts[card_num] + 1), G1ConcRSHotCardLimit));
     }
   }
   return count;
@@ -165,31 +100,23 @@
 }
 
 void G1CardCounts::clear_region(HeapRegion* hr) {
-  assert(!hr->isHumongous(), "Should have been cleared");
-  if (has_count_table()) {
-    HeapWord* bottom = hr->bottom();
+  MemRegion mr(hr->bottom(), hr->end());
+  clear_range(mr);
+}
 
-    // We use the last address in hr as hr could be the
-    // last region in the heap. In which case trying to find
-    // the card for hr->end() will be an OOB access to the
-    // card table.
-    HeapWord* last = hr->end() - 1;
-    assert(_g1h->g1_committed().contains(last),
-           err_msg("last not in committed: "
-                   "last: " PTR_FORMAT ", "
-                   "committed: [" PTR_FORMAT ", " PTR_FORMAT ")",
-                   last,
-                   _g1h->g1_committed().start(),
-                   _g1h->g1_committed().end()));
-
-    const jbyte* from_card_ptr = _ct_bs->byte_for_const(bottom);
-    const jbyte* last_card_ptr = _ct_bs->byte_for_const(last);
+void G1CardCounts::clear_range(MemRegion mr) {
+  if (has_count_table()) {
+    const jbyte* from_card_ptr = _ct_bs->byte_for_const(mr.start());
+    // We use the last address in the range as the range could represent the
+    // last region in the heap. In which case trying to find the card will be an
+    // OOB access to the card table.
+    const jbyte* last_card_ptr = _ct_bs->byte_for_const(mr.last());
 
 #ifdef ASSERT
     HeapWord* start_addr = _ct_bs->addr_for(from_card_ptr);
-    assert(start_addr == hr->bottom(), "alignment");
+    assert(start_addr == mr.start(), "MemRegion start must be aligned to a card.");
     HeapWord* last_addr = _ct_bs->addr_for(last_card_ptr);
-    assert((last_addr + CardTableModRefBS::card_size_in_words) == hr->end(), "alignment");
+    assert((last_addr + CardTableModRefBS::card_size_in_words) == mr.end(), "MemRegion end must be aligned to a card.");
 #endif // ASSERT
 
     // Clear the counts for the (exclusive) card range.
@@ -199,14 +126,22 @@
   }
 }
 
+class G1CardCountsClearClosure : public HeapRegionClosure {
+ private:
+  G1CardCounts* _card_counts;
+ public:
+  G1CardCountsClearClosure(G1CardCounts* card_counts) :
+    HeapRegionClosure(), _card_counts(card_counts) { }
+
+
+  virtual bool doHeapRegion(HeapRegion* r) {
+    _card_counts->clear_region(r);
+    return false;
+  }
+};
+
 void G1CardCounts::clear_all() {
   assert(SafepointSynchronize::is_at_safepoint(), "don't call this otherwise");
-  clear_range((size_t)0, _committed_max_card_num);
+  G1CardCountsClearClosure cl(this);
+  _g1h->heap_region_iterate(&cl);
 }
-
-G1CardCounts::~G1CardCounts() {
-  if (has_reserved_count_table()) {
-    _card_counts_storage.release();
-  }
-}
-