[heap] Aggressive code flushing in GC stress mode.

src/heap/objects-visiting-inl.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_OBJECTS_VISITING_INL_H_
 #define V8_OBJECTS_VISITING_INL_H_
 
 #include "src/heap/array-buffer-tracker.h"
 #include "src/heap/objects-visiting.h"
 #include "src/ic/ic-state.h"
@@ skipping 609 matching lines @@
   MarkBit code_mark = Marking::MarkBitFrom(function->code());
   if (Marking::IsBlackOrGrey(code_mark)) {
     return false;
   }
 
   // We do not (yet) flush code for optimized functions.
   if (function->code() != shared_info->code()) {
     return false;
   }
 
-  // Check age of optimized code.
-  if (FLAG_age_code && !function->code()->IsOld()) {
-    return false;
-  }
-
   return IsFlushable(heap, shared_info);
 }
 
 
 template <typename StaticVisitor>
 bool StaticMarkingVisitor<StaticVisitor>::IsFlushable(
     Heap* heap, SharedFunctionInfo* shared_info) {
   // Code is either on stack, in compilation cache or referenced
   // by optimized version of function.
   MarkBit code_mark = Marking::MarkBitFrom(shared_info->code());
@@ skipping 38 matching lines @@
   if (shared_info->IsBuiltin()) {
     return false;
   }
 
   // If this is a function initialized with %SetCode then the one-to-one
   // relation between SharedFunctionInfo and Code is broken.
   if (shared_info->dont_flush()) {
     return false;
   }
 
+  // ----------------------------------------------------------------
+  // The above predicates up to this line are hard invariants, below
+  // this line are heuristics that should not affect correctness.
+  // ----------------------------------------------------------------
+
+  // In stress mode we are aggressive.
+  if (FLAG_stress_compaction) {
+    return true;
+  }
+
   // Check age of code. If code aging is disabled we never flush.
   if (!FLAG_age_code || !shared_info->code()->IsOld()) {
     return false;
   }
 
   return true;
 }
 
 
 template <typename StaticVisitor>
@@ skipping 44 matching lines @@
   typedef FlexibleBodyVisitor<StaticVisitor, JSFunction::BodyDescriptorWeakCode,
                               void> JSFunctionWeakCodeBodyVisitor;
   JSFunctionWeakCodeBodyVisitor::Visit(map, object);
 }
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_OBJECTS_VISITING_INL_H_