Introduce `Fiber#storage` for inheritable fiber-scoped variables. (#6612)

1 files changed, 21 insertions, 0 deletions

diff --git a/include/ruby/internal/intern/cont.h b/include/ruby/internal/intern/cont.h
index 37493009f5..3ee8b08dee 100644
--- a/include/ruby/internal/intern/cont.h
+++ b/include/ruby/internal/intern/cont.h
@@ -39,6 +39,27 @@ RBIMPL_SYMBOL_EXPORT_BEGIN()
 VALUE rb_fiber_new(rb_block_call_func_t func, VALUE callback_obj);
 
 /**
+ * Creates a Fiber instance from a C-backended block with the specified storage.
+ *
+ * If the given storage is Qundef, this function is equivalent to
+ * rb_fiber_new() which inherits storage from the current fiber.
+ *
+ * If the given storage is Qfalse, this function uses the current fiber's
+ * storage by reference.
+ *
+ * If the given storage is Qnil, this function will lazy initialize the
+ * internal storage which starts of empty (without any inheritance).
+ *
+ * Otherwise, the given storage is used as the internal storage.
+ *
+ * @param[in]  func          A function, to become the fiber's body.
+ * @param[in]  callback_obj  Passed as-is to `func`.
+ * @return     An allocated  new instance  of rb_cFiber, which  is ready  to be
+ *             "resume"d.
+ */
+VALUE rb_fiber_new_storage(rb_block_call_func_t func, VALUE callback_obj, VALUE storage);
+
+/**
  * Queries  the fiber  which  is  calling this  function.   Any ruby  execution
  * context has its fiber, either explicitly or implicitly.
  *