Retain maps for several garbage collections

test/cctest/test-heap.cc

Index: test/cctest/test-heap.cc
diff --git a/test/cctest/test-heap.cc b/test/cctest/test-heap.cc
index ef870733d83b8e9d4aaf5c375f99123182f445ef..10cb7a0070b6be09c67ca6ad81ed868581dfdb15 100644
--- a/test/cctest/test-heap.cc
+++ b/test/cctest/test-heap.cc
@@ -1499,6 +1499,7 @@ TEST(TestInternalWeakLists) {
   // Some flags turn Scavenge collections into Mark-sweep collections
   // and hence are incompatible with this test case.
   if (FLAG_gc_global || FLAG_stress_compaction) return;
+  FLAG_retain_maps_for_n_gc = 0;
 
   static const int kNumTestContexts = 10;
 
@@ -2863,6 +2864,7 @@ TEST(Regress1465) {
   i::FLAG_stress_compaction = false;
   i::FLAG_allow_natives_syntax = true;
   i::FLAG_trace_incremental_marking = true;
+  i::FLAG_retain_maps_for_n_gc = 0;
   CcTest::InitializeVM();
   v8::HandleScope scope(CcTest::isolate());
   static const int transitions_count = 256;
@@ -2925,6 +2927,7 @@ static void AddPropertyTo(
   Handle<Smi> twenty_three(Smi::FromInt(23), isolate);
   i::FLAG_gc_interval = gc_count;
   i::FLAG_gc_global = true;
+  i::FLAG_retain_maps_for_n_gc = 0;
   CcTest::heap()->set_allocation_timeout(gc_count);
   JSReceiver::SetProperty(object, prop_name, twenty_three, SLOPPY).Check();
 }
@@ -4147,7 +4150,7 @@ TEST(EnsureAllocationSiteDependentCodesProcessed) {
   // Now make sure that a gc should get rid of the function, even though we
   // still have the allocation site alive.
   for (int i = 0; i < 4; i++) {
-    heap->CollectAllGarbage(Heap::kNoGCFlags);
+    heap->CollectAllGarbage(Heap::kAbortIncrementalMarkingMask);
   }
 
   // TODO(mvstanton): this test fails when FLAG_vector_ics is true because
@@ -4258,6 +4261,7 @@ TEST(NoWeakHashTableLeakWithIncrementalMarking) {
   i::FLAG_weak_embedded_objects_in_optimized_code = true;
   i::FLAG_allow_natives_syntax = true;
   i::FLAG_compilation_cache = false;
+  i::FLAG_retain_maps_for_n_gc = 0;
   CcTest::InitializeVM();
   Isolate* isolate = CcTest::i_isolate();
   v8::internal::Heap* heap = CcTest::heap();
@@ -4948,6 +4952,27 @@ TEST(Regress3631) {
 }
 
 
+TEST(MapRetaining) {

[Hannes Payer (out of office), 2014/12/16 17:15:35]

Please also test the flag for n == 0, n in between start and end, and n outside
start and end.

[ulan, 2014/12/17 11:13:34]

Done.

+  CcTest::InitializeVM();
+  v8::HandleScope scope(CcTest::isolate());
+  Isolate* isolate = CcTest::i_isolate();
+  Heap* heap = isolate->heap();
+  Handle<WeakCell> weak_cell;
+  {
+    HandleScope inner_scope(isolate);
+    Handle<Map> map = Map::Create(isolate, 1);
+    weak_cell = inner_scope.CloseAndEscape(Map::WeakCellForMap(map));
+  }
+  CHECK(!weak_cell->cleared());
+  for (int i = 0; i < FLAG_retain_maps_for_n_gc; i++) {
+    heap->CollectGarbage(OLD_POINTER_SPACE);
+  }
+  CHECK(!weak_cell->cleared());
+  heap->CollectGarbage(OLD_POINTER_SPACE);
+  CHECK(weak_cell->cleared());
+}
+
+
 #ifdef DEBUG
 TEST(PathTracer) {
   CcTest::InitializeVM();