MicroJIT: avoid having to invalidate running output code

1 files changed, 27 insertions, 0 deletions

diff --git a/test/ruby/test_microjit.rb b/test/ruby/test_microjit.rb
new file mode 100644
index 0000000000..f0c876b70f
--- /dev/null
+++ b/test/ruby/test_microjit.rb
@@ -0,0 +1,27 @@
+# frozen_string_literal: true
+require 'test/unit'
+
+class TestMicroJIT < Test::Unit::TestCase
+  # MicroJIT's code invalidation mechanism can't invalidate
+  # code that is executing. Test that we don't try to do that.
+  def test_code_invalidation
+    klass = Class.new do
+      def alias_then_hash(klass, method_to_redefine)
+        klass.alias_method(method_to_redefine, :itself)
+        hash
+      end
+    end
+
+    instance = klass.new
+    i = 0
+    while i < 12
+      if i < 11
+        instance.alias_then_hash(klass, :bar)
+      else
+        ret = instance.alias_then_hash(klass, :hash)
+        assert(instance.equal?(ret))
+      end
+      i += 1
+    end
+  end
+end