Introduce API to temporarily interrupt long running JavaScript code.

include/v8.h

Index: include/v8.h
diff --git a/include/v8.h b/include/v8.h
index 815f43db7b2fb392ec521940c3b43821f190196b..3a814f14b73b02073cb0666e339647ac70d3ee53 100644
--- a/include/v8.h
+++ b/include/v8.h
@@ -4117,6 +4117,8 @@ enum GCCallbackFlags {
 typedef void (*GCPrologueCallback)(GCType type, GCCallbackFlags flags);
 typedef void (*GCEpilogueCallback)(GCType type, GCCallbackFlags flags);
 
+typedef void (*InterruptCallback)(Isolate* isolate, void* data);
+
 
 /**
  * Collection of V8 heap information.
@@ -4377,6 +4379,23 @@ class V8_EXPORT Isolate {
    */
   void RemoveGCEpilogueCallback(GCEpilogueCallback callback);
 
+  /**
+   * Request V8 to interrupt long running JavaScript code and invoke
+   * the given |callback| passing the given |data| to it. After |callback|
+   * returns control will be returned to the JavaScript code.
+   * At any given moment V8 can remember only a single callback for the very
+   * last interrupt request.
+   * Can be called from another thread without acquiring a |Locker|.
+   * Registered |callback| must not reenter interrupted Isolate.
+   */
+  void RequestInterrupt(InterruptCallback callback, void* data);
+
+  /**
+   * Clear interrupt request created by |RequestInterrupt|.
+   * Can be called from another thread without acquiring a |Locker|.
+   */
+  void ClearInterrupt();
+
  private:
   Isolate();
   Isolate(const Isolate&);