ART: clear dirty cards of alloc space in pause phase

Clear the dirty cards of alloc spaces when scanning them in pause phase,
the dirty cards of image or zygote space will not be cleared in order to
track the references to the other spaces.

Change-Id: I519f071d954a589aa33dbce0cdba405f2d2cef71
Signed-off-by: Lei Li <lei.l.li@intel.com>

2 files changed, 11 insertions, 2 deletions

diff --git a/runtime/gc/accounting/card_table-inl.h b/runtime/gc/accounting/card_table-inl.h
index 15562e506e..83ad33e145 100644
--- a/runtime/gc/accounting/card_table-inl.h
+++ b/runtime/gc/accounting/card_table-inl.h
@@ -48,7 +48,7 @@ static inline bool byte_cas(uint8_t old_value, uint8_t new_value, uint8_t* addre
 #endif
 }
 
-template <typename Visitor>
+template <bool kClearCard, typename Visitor>
 inline size_t CardTable::Scan(ContinuousSpaceBitmap* bitmap, uint8_t* scan_begin, uint8_t* scan_end,
                               const Visitor& visitor, const uint8_t minimum_age) const {
   DCHECK_GE(scan_begin, reinterpret_cast<uint8_t*>(bitmap->HeapBegin()));
@@ -66,6 +66,9 @@ inline size_t CardTable::Scan(ContinuousSpaceBitmap* bitmap, uint8_t* scan_begin
       uintptr_t start = reinterpret_cast<uintptr_t>(AddrFromCard(card_cur));
       bitmap->VisitMarkedRange(start, start + kCardSize, visitor);
       ++cards_scanned;
+      if (kClearCard) {
+        *card_cur = 0;
+      }
     }
     ++card_cur;
   }
@@ -95,6 +98,9 @@ inline size_t CardTable::Scan(ContinuousSpaceBitmap* bitmap, uint8_t* scan_begin
             << "card " << static_cast<size_t>(*card) << " intptr_t " << (start_word & 0xFF);
         bitmap->VisitMarkedRange(start, start + kCardSize, visitor);
         ++cards_scanned;
+        if (kClearCard) {
+          *card = 0;
+        }
       }
       start_word >>= 8;
       start += kCardSize;
@@ -109,6 +115,9 @@ inline size_t CardTable::Scan(ContinuousSpaceBitmap* bitmap, uint8_t* scan_begin
       uintptr_t start = reinterpret_cast<uintptr_t>(AddrFromCard(card_cur));
       bitmap->VisitMarkedRange(start, start + kCardSize, visitor);
       ++cards_scanned;
+      if (kClearCard) {
+        *card_cur = 0;
+      }
     }
     ++card_cur;
   }
diff --git a/runtime/gc/accounting/card_table.h b/runtime/gc/accounting/card_table.h
index 9bd3fbaf7a..a84cf34300 100644
--- a/runtime/gc/accounting/card_table.h
+++ b/runtime/gc/accounting/card_table.h
@@ -101,7 +101,7 @@ class CardTable {
 
   // For every dirty at least minumum age between begin and end invoke the visitor with the
   // specified argument. Returns how many cards the visitor was run on.
-  template <typename Visitor>
+  template <bool kClearCard, typename Visitor>
   size_t Scan(SpaceBitmap<kObjectAlignment>* bitmap, uint8_t* scan_begin, uint8_t* scan_end,
               const Visitor& visitor,
               const uint8_t minimum_age = kCardDirty) const