Introduce an API mirroring the gc extension

include/v8.h

Index: include/v8.h
diff --git a/include/v8.h b/include/v8.h
index c56295ac78dd8a4c6561f97f12717e5972381520..5b311c4a57027a91a84276e9548bb0b686332f79 100644
--- a/include/v8.h
+++ b/include/v8.h
@@ -3973,6 +3973,15 @@ class V8_EXPORT Isolate {
   };
 
   /**
+   * Types of garbage collections that can be requested via
+   * RequestGarbageCollection.
+   */
+  enum GarbageCollectionType {
+    kFullGarbageCollection,
+    kMinorGarbageCollection
+  };
+
+  /**
    * Creates a new isolate.  Does not change the currently entered
    * isolate.
    *
@@ -4184,6 +4193,12 @@ class V8_EXPORT Isolate {
    */
   void ClearInterrupt();
 
+  /**
+   * Request garbage collection in this Isolate. If |minor| is true, a
+   * minor garbage collection is performed.
+   */
+  void RequestGarbageCollection(GarbageCollectionType type);

[Michael Starzinger, 2014/01/13 10:13:24]

I don't like exposing this through the API at all. This should never be called
in production code. IIUC it is only used to replace the gc-extension for tests.

As discussed offline with Jochen: Using a "ForTesting" postfix in the name would
prevent that. I would strongly argue for renaming it in that way.

Also the comment needs to be adapted saying that this actually tanks performance
and only exists for testing purposes. I was thinking along the lines of ...

/**
 * Request garbage collection in this Isolate. If |minor| is true, a
 * minor garbage collection is performed.
 *
 * This should only be used for testing purposes and not to enforce a garbage
 * collection schedule. It has strong negative impact on the garbage collection
 * performance. Use IdleNotification() or LowMemoryNotification() instead to
 * influence the garbage collection schedule.
 */

(yes, at least four lines saying "don't use this")

+
  private:
   Isolate();
   Isolate(const Isolate&);