Initial GetSample implementation.

include/v8.h

Index: include/v8.h
diff --git a/include/v8.h b/include/v8.h
index 73384946ba7d93594fd5c3d78753dfe01c2726f6..8491b22272240fa7c4c0a855cec86053af87c1ed 100644
--- a/include/v8.h
+++ b/include/v8.h
@@ -1298,6 +1298,41 @@ class V8_EXPORT StackFrame {
 
 
 /**
+ * Isolate::Getsample collects the current JS execution state as a sample.

[alph, 2014/09/08 12:47:40]

nit: GetSample

[gholap, 2014/09/08 23:57:38]

Done.

+ * A collected sample contains program counter values.
+ *
+ * Example: Printing out the stack frames' addresses, from top to bottom.
+ *
+ * Isolate* isolate = Isolate::Current();
+ * Sample sample;
+ * isolate->GetSample(&sample);
+ * const void* const* i;
+ * for (i = sample.begin(); i != sample.end(); ++i) {
+ *   printf("%p\n", *i);
+ * }
+ */
+class V8_EXPORT Sample {
+ public:
+  enum { kMaxSize = 255u };
+
+  Sample() : size_(0) {}
+  template <class InputIterator>
+  Sample(InputIterator first, InputIterator last) : size_(0) {
+    for (; first != last && size_ < kMaxSize; ++first)
+      data_[size_++] = *first;
+  }
+
+  typedef const void* const* const_iterator;
+  const_iterator begin() const { return &data_[0]; }
+  const_iterator end() const { return &data_[size_]; }
+  size_t size() const { return size_; }
+
+ private:
+  void const* data_[kMaxSize];

[alph, 2014/09/08 12:47:40]

nit: const void

[gholap, 2014/09/08 23:57:38]

Done.

+  size_t size_;
+};
+
+/**
  * A JSON Parser.
  */
 class V8_EXPORT JSON {
@@ -4217,6 +4252,11 @@ class V8_EXPORT Isolate {
   void GetHeapStatistics(HeapStatistics* heap_statistics);
 
   /**
+   * Get a sample from the isolate.
+   */
+  void GetSample(Sample* sample);
+
+  /**
    * Adjusts the amount of registered external memory. Used to give V8 an
    * indication of the amount of externally allocated memory that is kept alive
    * by JavaScript objects. V8 uses this to decide when to perform global