Fix call stack sampling for the case when native callback invokes JS function

src/frames.cc

 // 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 18 matching lines @@
 
 #include "ast.h"
 #include "deoptimizer.h"
 #include "frames-inl.h"
 #include "full-codegen.h"
 #include "lazy-instance.h"
 #include "mark-compact.h"
 #include "safepoint-table.h"
 #include "scopeinfo.h"
 #include "string-stream.h"
+#include "vm-state-inl.h"
 
 #include "allocation-inl.h"
 
 namespace v8 {
 namespace internal {
 
 
 ReturnAddressLocationResolver
     StackFrame::return_address_location_resolver_ = NULL;
 
@@ skipping 165 matching lines @@
 
 // -------------------------------------------------------------------------
 
 
 SafeStackFrameIterator::SafeStackFrameIterator(
     Isolate* isolate,
     Address fp, Address sp, Address js_entry_sp)
     : StackFrameIteratorBase(isolate, false),
       low_bound_(sp),
       high_bound_(js_entry_sp),
-      top_frame_type_(StackFrame::NONE) {
+      top_frame_type_(StackFrame::NONE),
+      external_callback_scope_(isolate->external_callback_scope()) {
   StackFrame::State state;
   StackFrame::Type type;
   ThreadLocalTop* top = isolate->thread_local_top();
   if (IsValidTop(top)) {
     type = ExitFrame::GetStateForFramePointer(Isolate::c_entry_fp(top), &state);
     top_frame_type_ = type;
   } else if (IsValidStackAddress(fp)) {
     ASSERT(fp != NULL);
     state.fp = fp;
     state.sp = sp;
@@ skipping 15 matching lines @@
       type = StackFrame::JAVA_SCRIPT;
       // Top frame is incomplete so we cannot reliably determine its type.
       top_frame_type_ = StackFrame::NONE;
     }
   } else {
     return;
   }
   if (SingletonFor(type) == NULL) return;
   frame_ = SingletonFor(type, &state);
 
   if (!done()) Advance();

[loislo, 2013/07/22 14:18:54]

if (frame_ == NULL) return;

Advance();

if (frame_ != NULL &&
    !frame_->is_exit() &&
    external_callback_scope_ &&
    external_callback_scope_->scope_address() < frame_->fp()) {
  // Skip top ExternalCallbackScope if we already advanced to a JS frame
  // under it. Sampler will anyways take this top external callback.
  external_callback_scope_ = external_callback_scope_->previous();
}

[yurys, 2013/07/22 14:24:08]

Done.

+
+  if (done() || frame_->is_exit() || external_callback_scope_ == NULL) return;
+  if (external_callback_scope_->scope_address() < frame_->fp()) {
+    // Skip top ExternalCallbackScope if we already advanced to a JS frame
+    // under it. Sampler will anyways take this top external callback.
+    external_callback_scope_ = external_callback_scope_->previous();
+  }
 }
 
 
 bool SafeStackFrameIterator::IsValidTop(ThreadLocalTop* top) const {
-  Address fp = Isolate::c_entry_fp(top);
-  if (!IsValidExitFrame(fp)) return false;
+  Address c_entry_fp = Isolate::c_entry_fp(top);
+  if (!IsValidExitFrame(c_entry_fp)) return false;
   // There should be at least one JS_ENTRY stack handler.
-  return Isolate::handler(top) != NULL;
+  Address handler = Isolate::handler(top);
+  if (handler == NULL) return false;
+  // Check that there are no js frames on top of the native frames.
+  return c_entry_fp < handler;
 }
 
 
 void SafeStackFrameIterator::AdvanceOneFrame() {
   ASSERT(!done());
   StackFrame* last_frame = frame_;
   Address last_sp = last_frame->sp(), last_fp = last_frame->fp();
   // Before advancing to the next stack frame, perform pointer validity tests.
   if (!IsValidFrame(last_frame) || !IsValidCaller(last_frame)) {
     frame_ = NULL;
@@ skipping 54 matching lines @@
   }
   return *state.pc_address != NULL;
 }
 
 
 void SafeStackFrameIterator::Advance() {
   while (true) {
     AdvanceOneFrame();
     if (done()) return;
     if (frame_->is_java_script()) return;
+    if (frame_->is_exit() && external_callback_scope_) {
+      // Some of the EXIT frames may have ExternalCallbackScope allocated on
+      // top of them. In that case the scope corresponds to the first EXIT
+      // frame beneath it. There may be other EXIT frames on top of the
+      // ExternalCallbackScope, just skip them as we cannot collect any useful
+      // information about them.
+      if (external_callback_scope_->scope_address() < frame_->fp()) {
+        Address* callback_address =
+            external_callback_scope_->callback_address();
+        if (*callback_address != NULL) {
+          frame_->state_.pc_address = callback_address;
+        }
+        external_callback_scope_ = external_callback_scope_->previous();
+        return;
+      }
+    }
   }
 }
 
 
 // -------------------------------------------------------------------------
 
 
 Code* StackFrame::GetSafepointData(Isolate* isolate,
                                    Address inner_pointer,
                                    SafepointEntry* safepoint_entry,
@@ skipping 1243 matching lines @@
   ZoneList<StackFrame*> list(10, zone);
   for (StackFrameIterator it(isolate); !it.done(); it.Advance()) {
     StackFrame* frame = AllocateFrameCopy(it.frame(), zone);
     list.Add(frame, zone);
   }
   return list.ToVector();
 }
 
 
 } }  // namespace v8::internal