Revert r7483 "Move SafeStackFrameIterator::active_count_ into an isolate."

It broke the Mac build.

Sampler::SampleStack() can't use Isolate::Current() when called from
the sampler thread (from SampleContext). We have to pass the isolate
pointer.

TBR=mikhail.naganov@gmail.com

Review URL: http://codereview.chromium.org/6791014

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7485 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/frames.cc

@@ -39,6 +39,9 @@
 namespace v8 {
 namespace internal {
 
+
+int SafeStackFrameIterator::active_count_ = 0;
+
 // Iterator that supports traversing the stack handlers of a
 // particular frame. Needs to know the top of the handler chain.
 class StackHandlerIterator BASE_EMBEDDED {
@@ -218,24 +221,10 @@ bool SafeStackFrameIterator::ExitFrameValidator::IsValidFP(Address fp) {
 }
 
 
-SafeStackFrameIterator::ActiveCountMaintainer::ActiveCountMaintainer(
-    Isolate* isolate)
-    : isolate_(isolate) {
-  isolate_->set_safe_stack_iterator_counter(
-      isolate_->safe_stack_iterator_counter() + 1);
-}
-
-
-SafeStackFrameIterator::ActiveCountMaintainer::~ActiveCountMaintainer() {
-  isolate_->set_safe_stack_iterator_counter(
-      isolate_->safe_stack_iterator_counter() - 1);
-}
-
-
 SafeStackFrameIterator::SafeStackFrameIterator(
     Isolate* isolate,
     Address fp, Address sp, Address low_bound, Address high_bound) :
-    maintainer_(isolate),
+    maintainer_(),
     stack_validator_(low_bound, high_bound),
     is_valid_top_(IsValidTop(isolate, low_bound, high_bound)),
     is_valid_fp_(IsWithinBounds(low_bound, high_bound, fp)),
@@ -244,10 +233,6 @@ SafeStackFrameIterator::SafeStackFrameIterator(
     iterator_(isolate, is_valid_top_, is_valid_fp_ ? fp : NULL, sp) {
 }
 
-bool SafeStackFrameIterator::is_active(Isolate* isolate) {
-  return isolate->safe_stack_iterator_counter() > 0;
-}
-
 
 bool SafeStackFrameIterator::IsValidTop(Isolate* isolate,
                                         Address low_bound, Address high_bound) {
@@ -403,14 +388,13 @@ StackFrame::Type StackFrame::ComputeType(State* state) {
   const int offset = StandardFrameConstants::kMarkerOffset;
   Object* marker = Memory::Object_at(state->fp + offset);
   if (!marker->IsSmi()) {
-    Isolate* isolate = Isolate::Current();
     // If we're using a "safe" stack iterator, we treat optimized
     // frames as normal JavaScript frames to avoid having to look
     // into the heap to determine the state. This is safe as long
     // as nobody tries to GC...
-    if (SafeStackFrameIterator::is_active(isolate))
-      return JAVA_SCRIPT;
-    Code::Kind kind = GetContainingCode(isolate, *(state->pc_address))->kind();
+    if (SafeStackFrameIterator::is_active()) return JAVA_SCRIPT;
+    Code::Kind kind = GetContainingCode(Isolate::Current(),
+                                        *(state->pc_address))->kind();
     ASSERT(kind == Code::FUNCTION || kind == Code::OPTIMIZED_FUNCTION);
     return (kind == Code::OPTIMIZED_FUNCTION) ? OPTIMIZED : JAVA_SCRIPT;
   }
@@ -555,7 +539,7 @@ void OptimizedFrame::Iterate(ObjectVisitor* v) const {
 
   // Make sure that we're not doing "safe" stack frame iteration. We cannot
   // possibly find pointers in optimized frames in that state.
-  ASSERT(!SafeStackFrameIterator::is_active(Isolate::Current()));
+  ASSERT(!SafeStackFrameIterator::is_active());
 
   // Compute the safepoint information.
   unsigned stack_slots = 0;
@@ -656,9 +640,8 @@ Code* JavaScriptFrame::unchecked_code() const {
 
 Address JavaScriptFrame::GetCallerStackPointer() const {
   int arguments;
-  Isolate* isolate = Isolate::Current();
-  if (SafeStackFrameIterator::is_active(isolate) ||
-      isolate->heap()->gc_state() != Heap::NOT_IN_GC) {
+  if (SafeStackFrameIterator::is_active() ||
+      HEAP->gc_state() != Heap::NOT_IN_GC) {
     // If the we are currently iterating the safe stack the
     // arguments for frames are traversed as if they were
     // expression stack elements of the calling frame. The reason for

src/frames.h

@@ -739,7 +739,7 @@ class SafeStackFrameIterator BASE_EMBEDDED {
   void Advance();
   void Reset();
 
-  static bool is_active(Isolate* isolate);
+  static bool is_active() { return active_count_ > 0; }
 
   static bool IsWithinBounds(
       Address low_bound, Address high_bound, Address addr) {
@@ -786,13 +786,13 @@ class SafeStackFrameIterator BASE_EMBEDDED {
   // heap objects.
   class ActiveCountMaintainer BASE_EMBEDDED {
    public:
-    explicit ActiveCountMaintainer(Isolate* isolate);
-    ~ActiveCountMaintainer();
-   private:
-    Isolate* isolate_;
+    ActiveCountMaintainer() { active_count_++; }
+    ~ActiveCountMaintainer() { active_count_--; }
   };
 
   ActiveCountMaintainer maintainer_;
+  // TODO(isolates): this is dangerous.
+  static int active_count_;
   StackAddressValidator stack_validator_;
   const bool is_valid_top_;
   const bool is_valid_fp_;

src/isolate.h

@@ -316,8 +316,6 @@ typedef List<HeapObject*, PreallocatedStorage> DebugObjectCache;
   /* AstNode state. */                                                         \
   V(unsigned, ast_node_id, 0)                                                  \
   V(unsigned, ast_node_count, 0)                                               \
-  /* SafeStackFrameIterator activations count. */                              \
-  V(int, safe_stack_iterator_counter, 0)                                       \
   ISOLATE_PLATFORM_INIT_LIST(V)                                                \
   ISOLATE_LOGGING_INIT_LIST(V)                                                 \
   ISOLATE_DEBUGGER_INIT_LIST(V)