Introduce Ractor::IsolationError

Ractor has several restrictions to keep each ractor being isolated
and some operation such as `CONST="foo"` in non-main ractor raises
an exception. This kind of operation raises an error but there is
confusion (some code raises RuntimeError and some code raises
NameError).

To make clear we introduce Ractor::IsolationError which is raised
when the isolation between ractors is violated.

1 files changed, 9 insertions, 12 deletions

diff --git a/ractor.c b/ractor.c
index 8c4f06a6b0..b8564199d5 100644
--- a/ractor.c
+++ b/ractor.c
@@ -18,18 +18,14 @@
 #include "transient_heap.h"
 
 VALUE rb_cRactor;
+
+VALUE rb_eRactorUnsafeError;
+VALUE rb_eRactorIsolationError;
 static VALUE rb_eRactorError;
 static VALUE rb_eRactorRemoteError;
 static VALUE rb_eRactorMovedError;
 static VALUE rb_eRactorClosedError;
 static VALUE rb_cRactorMovedObject;
-VALUE rb_eRactorUnsafeError;
-
-VALUE
-rb_ractor_error_class(void)
-{
-    return rb_eRactorError;
-}
 
 static void vm_ractor_blocking_cnt_inc(rb_vm_t *vm, rb_ractor_t *r, const char *file, int line);
 
@@ -2023,11 +2019,12 @@ void
 Init_Ractor(void)
 {
     rb_cRactor = rb_define_class("Ractor", rb_cObject);
-    rb_eRactorError       = rb_define_class_under(rb_cRactor, "Error", rb_eRuntimeError);
-    rb_eRactorRemoteError = rb_define_class_under(rb_cRactor, "RemoteError", rb_eRactorError);
-    rb_eRactorMovedError  = rb_define_class_under(rb_cRactor, "MovedError",  rb_eRactorError);
-    rb_eRactorClosedError = rb_define_class_under(rb_cRactor, "ClosedError", rb_eStopIteration);
-    rb_eRactorUnsafeError = rb_define_class_under(rb_cRactor, "UnsafeError", rb_eRactorError);
+    rb_eRactorError          = rb_define_class_under(rb_cRactor, "Error", rb_eRuntimeError);
+    rb_eRactorIsolationError = rb_define_class_under(rb_cRactor, "IsolationError", rb_eRactorError);
+    rb_eRactorRemoteError    = rb_define_class_under(rb_cRactor, "RemoteError", rb_eRactorError);
+    rb_eRactorMovedError     = rb_define_class_under(rb_cRactor, "MovedError",  rb_eRactorError);
+    rb_eRactorClosedError    = rb_define_class_under(rb_cRactor, "ClosedError", rb_eStopIteration);
+    rb_eRactorUnsafeError    = rb_define_class_under(rb_cRactor, "UnsafeError", rb_eRactorError);
 
     rb_cRactorMovedObject = rb_define_class_under(rb_cRactor, "MovedObject", rb_cBasicObject);
     rb_undef_alloc_func(rb_cRactorMovedObject);