Introduce BeforeCallEnteredCallback.

include/v8.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 /** \mainpage V8 API Reference Guide
  *
  * V8 is Google's open source JavaScript engine.
  *
  * This set of documents provides reference material generated from the
  * V8 header file, include/v8.h.
@@ skipping 4991 matching lines @@
   enum AllocationAction {
     kAllocationActionAllocate = 1 << 0,
     kAllocationActionFree = 1 << 1,
     kAllocationActionAll = kAllocationActionAllocate | kAllocationActionFree
   };
 
 typedef void (*MemoryAllocationCallback)(ObjectSpace space,
                                          AllocationAction action,
                                          int size);
 
-// --- Leave Script Callback ---
+// --- Enter/Leave Script Callback ---
+typedef void (*BeforeCallEnteredCallback)(Isolate*);

[jochen (gone - plz use gerrit), 2016/02/17 12:58:48]

what's the reason we need an isolate ptr here, but not on the call completed
callback?

[dgozman, 2016/02/17 16:51:12]

Passing isolate replaces the need to call Isolate::GetCurrent from inside the
callback. I think that's a cleaner contract which does not assume anything about
entered isolate before making a call.

 typedef void (*CallCompletedCallback)();

[jochen (gone - plz use gerrit), 2016/02/18 13:48:38]

can you add an isolate* parameter here as well then?

you can typedef void (*DeprecatedCallCompletedCallback)(); and then overload the
methods to add and remove the callback.

Due to C calling conventions, it's safe to reinterpret_cast<> the deprecated to
a new one internally

[dgozman, 2016/02/19 01:59:42]

Done.

 
 // --- Promise Reject Callback ---
 enum PromiseRejectEvent {
   kPromiseRejectWithNoHandler = 0,
   kPromiseHandlerAddedAfterReject = 1
 };
 
 class PromiseRejectMessage {
  public:
   PromiseRejectMessage(Local<Promise> promise, PromiseRejectEvent event,
@@ skipping 779 matching lines @@
    * schedule.
    */
   void RequestGarbageCollectionForTesting(GarbageCollectionType type);
 
   /**
    * Set the callback to invoke for logging event.
    */
   void SetEventLogger(LogEventCallback that);
 
   /**
+   * Adds a callback to notify the host application right before a script
+   * is about to run. If a script re-enters the runtime during executing, the
+   * BeforeCallEnteredCallback is invoked for each re-entrance.
+   * Executing scripts inside the callback will re-trigger the callback.
+   */
+  void AddBeforeCallEnteredCallback(BeforeCallEnteredCallback callback);
+
+  /**
+   * Removes callback that was installed by AddBeforeCallEnteredCallback.
+   */
+  void RemoveBeforeCallEnteredCallback(BeforeCallEnteredCallback callback);
+
+  /**
    * Adds a callback to notify the host application when a script finished
    * running.  If a script re-enters the runtime during executing, the
    * CallCompletedCallback is only invoked when the outer-most script
    * execution ends.  Executing scripts inside the callback do not trigger
    * further callbacks.
    */
   void AddCallCompletedCallback(CallCompletedCallback callback);
 
   /**
    * Removes callback that was installed by AddCallCompletedCallback.
    */
   void RemoveCallCompletedCallback(CallCompletedCallback callback);
 
-
   /**
    * Set callback to notify about promise reject with no handler, or
    * revocation of such a previous notification once the handler is added.
    */
   void SetPromiseRejectCallback(PromiseRejectCallback callback);
 
   /**
    * Experimental: Runs the Microtask Work Queue until empty
    * Any exceptions thrown by microtask callbacks are swallowed.
    */
@@ skipping 2698 matching lines @@
  */
 
 
 }  // namespace v8
 
 
 #undef TYPE_CHECK
 
 
 #endif  // INCLUDE_V8_H_