Move code flushing support into shared visitor.

src/mark-compact.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 414 matching lines @@
  private:
   static const int kChainLengthThreshold = 15;
 
   intptr_t idx_;
   intptr_t chain_length_;
   SlotsBuffer* next_;
   ObjectSlot slots_[kNumberOfElements];
 };
 
 
+// CodeFlusher collects candidates for code flushing during marking and
+// processes those candidates after marking has completed in order to
+// reset those functions referencing code objects that would otherwise
+// be unreachable. Code objects can be referenced in two ways:
+//    - SharedFunctionInfo references unoptimized code.
+//    - JSFunction references either unoptimized or optimized code.
+// We are not allowed to flush unoptimized code for functions that got
+// optimized or inlined into optimized code, because we might bailout
+// into the unoptimized code again during deoptimization.
+class CodeFlusher {
+ public:
+  explicit CodeFlusher(Isolate* isolate)
+      : isolate_(isolate),
+        jsfunction_candidates_head_(NULL),
+        shared_function_info_candidates_head_(NULL) {}
+
+  void AddCandidate(SharedFunctionInfo* shared_info) {
+    SetNextCandidate(shared_info, shared_function_info_candidates_head_);
+    shared_function_info_candidates_head_ = shared_info;
+  }
+
+  void AddCandidate(JSFunction* function) {
+    ASSERT(function->code() == function->shared()->code());
+    SetNextCandidate(function, jsfunction_candidates_head_);
+    jsfunction_candidates_head_ = function;
+  }
+
+  void ProcessCandidates() {
+    ProcessSharedFunctionInfoCandidates();
+    ProcessJSFunctionCandidates();
+  }
+
+ private:
+  void ProcessJSFunctionCandidates();
+  void ProcessSharedFunctionInfoCandidates();
+
+  static JSFunction** GetNextCandidateField(JSFunction* candidate) {
+    return reinterpret_cast<JSFunction**>(
+        candidate->address() + JSFunction::kCodeEntryOffset);
+  }
+
+  static JSFunction* GetNextCandidate(JSFunction* candidate) {
+    return *GetNextCandidateField(candidate);
+  }
+
+  static void SetNextCandidate(JSFunction* candidate,
+                               JSFunction* next_candidate) {
+    *GetNextCandidateField(candidate) = next_candidate;
+  }
+
+  static SharedFunctionInfo** GetNextCandidateField(
+      SharedFunctionInfo* candidate) {
+    Code* code = candidate->code();
+    return reinterpret_cast<SharedFunctionInfo**>(
+        code->address() + Code::kGCMetadataOffset);
+  }
+
+  static SharedFunctionInfo* GetNextCandidate(SharedFunctionInfo* candidate) {
+    return reinterpret_cast<SharedFunctionInfo*>(
+        candidate->code()->gc_metadata());
+  }
+
+  static void SetNextCandidate(SharedFunctionInfo* candidate,
+                               SharedFunctionInfo* next_candidate) {
+    candidate->code()->set_gc_metadata(next_candidate);
+  }
+
+  Isolate* isolate_;
+  JSFunction* jsfunction_candidates_head_;
+  SharedFunctionInfo* shared_function_info_candidates_head_;
+
+  DISALLOW_COPY_AND_ASSIGN(CodeFlusher);
+};
+
+
 // Defined in isolate.h.
 class ThreadLocalTop;
 
 
 // -------------------------------------------------------------------------
 // Mark-Compact collector
 class MarkCompactCollector {
  public:
   // Type of functions to compute forwarding addresses of objects in
   // compacted spaces.  Given an object and its size, return a (non-failure)
@@ skipping 211 matching lines @@
   //          normal state.
   //
   //   After: Live objects are marked and non-live objects are unmarked.
 
   friend class RootMarkingVisitor;
   friend class MarkingVisitor;
   friend class MarkCompactMarkingVisitor;
   friend class CodeMarkingVisitor;
   friend class SharedFunctionInfoMarkingVisitor;
 
-  // Mark non-optimize code for functions inlined into the given optimized
-  // code. This will prevent it from being flushed.
-  void MarkInlinedFunctionsCode(Code* code);
-
   // Mark code objects that are active on the stack to prevent them
   // from being flushed.
   void PrepareThreadForCodeFlushing(Isolate* isolate, ThreadLocalTop* top);
 
   void PrepareForCodeFlushing();
 
   // Marking operations for objects reachable from roots.
   void MarkLiveObjects();
 
   void AfterMarking();
@@ skipping 114 matching lines @@
 
   friend class Heap;
 };
 
 
 const char* AllocationSpaceName(AllocationSpace space);
 
 } }  // namespace v8::internal
 
 #endif  // V8_MARK_COMPACT_H_