Fix race in root marking.

There was a race which caused the class linker / intern table to not
become dirty after adding a root. We now guard the is dirty flag by
the corresponding locks to prevent this from occuring. This was
causing roots to be occasionally missed.

Also fixes the bug where we occasionally scan more cards than
needed.

Bug: 10626133

Change-Id: I0f6e72d92035ff463954d66988ef610ea0df61be

1 files changed, 2 insertions, 7 deletions

diff --git a/runtime/intern_table.h b/runtime/intern_table.h
index a804d1f..07615dc 100644
--- a/runtime/intern_table.h
+++ b/runtime/intern_table.h
@@ -62,15 +62,10 @@ class InternTable {
 
   size_t Size() const;
 
-  void VisitRoots(RootVisitor* visitor, void* arg, bool clean_dirty);
+  void VisitRoots(RootVisitor* visitor, void* arg, bool only_dirty, bool clean_dirty);
 
   void DumpForSigQuit(std::ostream& os) const;
 
-  bool IsDirty() const { return is_dirty_; }
-  void Dirty() {
-    is_dirty_ = true;
-  }
-
  private:
   typedef std::multimap<int32_t, mirror::String*> Table;
 
@@ -83,7 +78,7 @@ class InternTable {
   void Remove(Table& table, const mirror::String* s, uint32_t hash_code);
 
   mutable Mutex intern_table_lock_;
-  bool is_dirty_;
+  bool is_dirty_ GUARDED_BY(intern_table_lock_);
   Table strong_interns_ GUARDED_BY(intern_table_lock_);
   Table weak_interns_ GUARDED_BY(intern_table_lock_);
 };