Simplify isolates access during stack iteration (WAS: Move SafeStackFrameIterator::active_count_...)

src/frames.h

 // Copyright 2006-2008 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 140 matching lines @@
     NO_ID = 0
   };
 
   struct State {
     State() : sp(NULL), fp(NULL), pc_address(NULL) { }
     Address sp;
     Address fp;
     Address* pc_address;
   };
 
-  // Copy constructor; it breaks the connection to host iterator.
+  // Copy constructor; it breaks the connection to host iterator
+  // (as an iterator usually lives on stack). But as we need
+  // a pointer to isolate, we store it in place of the iterator ptr,
+  // and tag accordingly.
   StackFrame(const StackFrame& original) {
     this->state_ = original.state_;
-    this->iterator_ = NULL;
+    this->tagged_isolate_ptr_ =
+        reinterpret_cast<intptr_t>(original.isolate()) | kIsolateTag;
   }
 
   // Type testers.
   bool is_entry() const { return type() == ENTRY; }
   bool is_entry_construct() const { return type() == ENTRY_CONSTRUCT; }
   bool is_exit() const { return type() == EXIT; }
   bool is_optimized() const { return type() == OPTIMIZED; }
   bool is_arguments_adaptor() const { return type() == ARGUMENTS_ADAPTOR; }
   bool is_internal() const { return type() == INTERNAL; }
   bool is_construct() const { return type() == CONSTRUCT; }
@@ skipping 23 matching lines @@
   bool HasHandler() const;
 
   // Get the type of this frame.
   virtual Type type() const = 0;
 
   // Get the code associated with this frame.
   // This method could be called during marking phase of GC.
   virtual Code* unchecked_code() const = 0;
 
   // Get the code associated with this frame.
-  Code* LookupCode(Isolate* isolate) const {
-    return GetContainingCode(isolate, pc());
+  Code* LookupCode() const {
+    return GetContainingCode(isolate(), pc());
   }
 
   // Get the code object that contains the given pc.
   static inline Code* GetContainingCode(Isolate* isolate, Address pc);
 
   // Get the code object containing the given pc and fill in the
   // safepoint entry and the number of stack slots. The pc must be at
   // a safepoint.
-  static Code* GetSafepointData(Address pc,
+  static Code* GetSafepointData(Isolate* isolate,
+                                Address pc,
                                 SafepointEntry* safepoint_entry,
                                 unsigned* stack_slots);
 
   virtual void Iterate(ObjectVisitor* v) const = 0;
   static void IteratePc(ObjectVisitor* v, Address* pc_address, Code* holder);
 
 
   // Printing support.
   enum PrintMode { OVERVIEW, DETAILS };
   virtual void Print(StringStream* accumulator,
                      PrintMode mode,
                      int index) const { }
 
  protected:
   explicit StackFrame(StackFrameIterator* iterator) : iterator_(iterator) { }
   virtual ~StackFrame() { }
 
+  inline Isolate* isolate() const;
+
   // Compute the stack pointer for the calling frame.
   virtual Address GetCallerStackPointer() const = 0;
 
   // Printing support.
   static void PrintIndex(StringStream* accumulator,
                          PrintMode mode,
                          int index);
 
   // Get the top handler from the current stack iterator.
   inline StackHandler* top_handler() const;
 
   // Compute the stack frame type for the given state.
-  static Type ComputeType(State* state);
+  static Type ComputeType(Isolate* isolate, State* state);
 
  private:
-  const StackFrameIterator* iterator_;
+  union {
+    const StackFrameIterator* iterator_;
+    intptr_t tagged_isolate_ptr_;
+  };
   State state_;
 
   // Fill in the state of the calling frame.
   virtual void ComputeCallerState(State* state) const = 0;
 
   // Get the type and the state of the calling frame.
   virtual Type GetCallerState(State* state) const;
 
+  static const intptr_t kIsolateTag = 1;
+
   friend class StackFrameIterator;
   friend class StackHandlerIterator;
   friend class SafeStackFrameIterator;
 
  private:
   void operator=(const StackFrame& original);
 };
 
 
 // Entry frames are used to enter JavaScript execution from C.
@@ skipping 332 matching lines @@
   explicit ConstructFrame(StackFrameIterator* iterator)
       : InternalFrame(iterator) { }
 
  private:
   friend class StackFrameIterator;
 };
 
 
 class StackFrameIterator BASE_EMBEDDED {
  public:
-  // An iterator that iterates over the current thread's stack.
+  // An iterator that iterates over the current thread's stack,
+  // and uses current isolate.
   StackFrameIterator();
 
+  // An iterator that iterates over the isolate's current thread's stack,
+  explicit StackFrameIterator(Isolate* isolate);
+
   // An iterator that iterates over a given thread's stack.
-  explicit StackFrameIterator(ThreadLocalTop* thread);
+  StackFrameIterator(Isolate* isolate, ThreadLocalTop* t);
 
   // An iterator that can start from a given FP address.
   // If use_top, then work as usual, if fp isn't NULL, use it,
   // otherwise, do nothing.
   StackFrameIterator(Isolate* isolate, bool use_top, Address fp, Address sp);
 
   StackFrame* frame() const {
     ASSERT(!done());
     return frame_;
   }
 
+  Isolate* isolate() const { return isolate_; }
+
   bool done() const { return frame_ == NULL; }
   void Advance() { (this->*advance_)(); }
 
   // Go back to the first frame.
   void Reset();
 
  private:
 #define DECLARE_SINGLETON(ignore, type) type type##_;
   STACK_FRAME_TYPE_LIST(DECLARE_SINGLETON)
 #undef DECLARE_SINGLETON
   StackFrame* frame_;
   StackHandler* handler_;
+  Isolate* isolate_;
   ThreadLocalTop* thread_;
   Address fp_;
   Address sp_;
   void (StackFrameIterator::*advance_)();
 
   StackHandler* handler() const {
     ASSERT(!done());
     return handler_;
   }
 
@@ skipping 10 matching lines @@
   DISALLOW_COPY_AND_ASSIGN(StackFrameIterator);
 };
 
 
 // Iterator that supports iterating through all JavaScript frames.
 template<typename Iterator>
 class JavaScriptFrameIteratorTemp BASE_EMBEDDED {
  public:
   JavaScriptFrameIteratorTemp() { if (!done()) Advance(); }
 
-  explicit JavaScriptFrameIteratorTemp(ThreadLocalTop* thread) :
-      iterator_(thread) {
-    if (!done()) Advance();
-  }
+  inline explicit JavaScriptFrameIteratorTemp(Isolate* isolate);
 
   // Skip frames until the frame with the given id is reached.
-  explicit JavaScriptFrameIteratorTemp(StackFrame::Id id);
+  explicit JavaScriptFrameIteratorTemp(StackFrame::Id id) { AdvanceToId(id); }
+
+  inline JavaScriptFrameIteratorTemp(Isolate* isolate, StackFrame::Id id);
 
   JavaScriptFrameIteratorTemp(Address fp, Address sp,
                               Address low_bound, Address high_bound) :
       iterator_(fp, sp, low_bound, high_bound) {
     if (!done()) Advance();
   }
 
   JavaScriptFrameIteratorTemp(Isolate* isolate,
                               Address fp, Address sp,
                               Address low_bound, Address high_bound) :
       iterator_(isolate, fp, sp, low_bound, high_bound) {
     if (!done()) Advance();
   }
 
   inline JavaScriptFrame* frame() const;
 
   bool done() const { return iterator_.done(); }
   void Advance();
 
   // Advance to the frame holding the arguments for the current
   // frame. This only affects the current frame if it has adapted
   // arguments.
   void AdvanceToArgumentsFrame();
 
   // Go back to the first frame.
   void Reset();
 
  private:
+  inline void AdvanceToId(StackFrame::Id id);
+
   Iterator iterator_;
 };
 
 
 typedef JavaScriptFrameIteratorTemp<StackFrameIterator> JavaScriptFrameIterator;
 
 
 // NOTE: The stack trace frame iterator is an iterator that only
 // traverse proper JavaScript frames; that is JavaScript frames that
 // have proper JavaScript functions. This excludes the problematic
 // functions in runtime.js.
 class StackTraceFrameIterator: public JavaScriptFrameIterator {
  public:
   StackTraceFrameIterator();
+  explicit StackTraceFrameIterator(Isolate* isolate);
   void Advance();
 
  private:
   bool IsValidFrame();
 };
 
 
 class SafeStackFrameIterator BASE_EMBEDDED {
  public:
   SafeStackFrameIterator(Isolate* isolate,
                          Address fp, Address sp,
                          Address low_bound, Address high_bound);
 
   StackFrame* frame() const {
     ASSERT(is_working_iterator_);
     return iterator_.frame();
   }
 
   bool done() const { return iteration_done_ ? true : iterator_.done(); }
 
   void Advance();
   void Reset();
 
-  static bool is_active() { return active_count_ > 0; }
+  static bool is_active(Isolate* isolate);
 
   static bool IsWithinBounds(
       Address low_bound, Address high_bound, Address addr) {
     return low_bound <= addr && addr <= high_bound;
   }
 
  private:
   class StackAddressValidator {
    public:
     StackAddressValidator(Address low_bound, Address high_bound)
@@ skipping 26 matching lines @@
   static bool IsValidTop(Isolate* isolate,
                          Address low_bound, Address high_bound);
 
   // This is a nasty hack to make sure the active count is incremented
   // before the constructor for the embedded iterator is invoked. This
   // is needed because the constructor will start looking at frames
   // right away and we need to make sure it doesn't start inspecting
   // heap objects.
   class ActiveCountMaintainer BASE_EMBEDDED {
    public:
-    ActiveCountMaintainer() { active_count_++; }
-    ~ActiveCountMaintainer() { active_count_--; }
+    explicit ActiveCountMaintainer(Isolate* isolate);
+    ~ActiveCountMaintainer();
+   private:
+    Isolate* isolate_;
   };
 
   ActiveCountMaintainer maintainer_;
-  // TODO(isolates): this is dangerous.
-  static int active_count_;
   StackAddressValidator stack_validator_;
   const bool is_valid_top_;
   const bool is_valid_fp_;
   const bool is_working_iterator_;
   bool iteration_done_;
   StackFrameIterator iterator_;
 };
 
 
 #ifdef ENABLE_LOGGING_AND_PROFILING
@@ skipping 22 matching lines @@
 };
 
 
 // Reads all frames on the current stack and copies them into the current
 // zone memory.
 Vector<StackFrame*> CreateStackMap();
 
 } }  // namespace v8::internal
 
 #endif  // V8_FRAMES_H_