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, 1 insertions, 2 deletions

diff --git a/vm.c b/vm.c
index ee28a2d4ad..9ed358f73d 100644
--- a/vm.c
+++ b/vm.c
@@ -994,7 +994,6 @@ collect_outer_variable_names(ID id, VALUE val, void *ptr)
     return ID_TABLE_CONTINUE;
 }
 
-VALUE rb_ractor_error_class(void);
 VALUE rb_ractor_make_shareable(VALUE obj);
 
 static const rb_env_t *
@@ -1015,7 +1014,7 @@ env_copy(const VALUE *src_ep, VALUE read_only_variables)
                 if (id ==  src_env->iseq->body->local_table[j]) {
                     VALUE v = src_env->env[j];
                     if (!rb_ractor_shareable_p(v)) {
-                        rb_raise(rb_ractor_error_class(),
+                        rb_raise(rb_eRactorIsolationError,
                                  "can not make shareable Proc because it can refer unshareable object %"
                                  PRIsVALUE" from variable `%s'", rb_inspect(v), rb_id2name(id));
                     }