Incremental changes from background compilation work

runtime/vm/object.cc

Index: runtime/vm/object.cc
diff --git a/runtime/vm/object.cc b/runtime/vm/object.cc
index cb3c236ceaed86a1656ef32bd8b97bfafd230697..29a74d5ebccb5df32c58735d0d7745feaafc5e94 100644
--- a/runtime/vm/object.cc
+++ b/runtime/vm/object.cc
@@ -9591,7 +9591,10 @@ bool Library::LookupResolvedNamesCache(const String& name,
   ResolvedNamesMap cache(resolved_names());
   bool present = false;
   *obj = cache.GetOrNull(name, &present);
-  ASSERT(cache.Release().raw() == resolved_names());
+  // Mutator compiler thread may add entries and therefore
+  // change 'resolved_names()' while running a background compilation;
+  // do not ASSERT that 'resolved_names()' has not changed.

[siva, 2015/12/22 19:43:46]

The background compiler will only add entries and not remove them, maybe there
is a way of asserting that, currently count_ is not exposed by hash map. We
could expose it and store old_count initially and then
add an assert to ensure the count doesn't become less than old_count.

[srdjan, 2015/12/22 20:23:10]

I agreed with you originally, but realized that the count is tied to the local
stack object, not to the array. Not doing anything for the moment.

+  cache.Release();
   return present;
 }