From a6f608c616265ee3ed4620edd646c8d9f1f25292 Mon Sep 17 00:00:00 2001
From: Wilson Snyder <wsnyder@wsnyder.org>
Date: Sun, 21 Dec 2025 15:28:10 -0500
Subject: [PATCH] Tests: Add t_rand_stability_class

---
 test_regress/t/t_rand_stability_class.py | 18 +++++++++++++
 test_regress/t/t_rand_stability_class.v  | 33 ++++++++++++++++++++++++
 2 files changed, 51 insertions(+)
 create mode 100755 test_regress/t/t_rand_stability_class.py
 create mode 100644 test_regress/t/t_rand_stability_class.v

diff --git a/test_regress/t/t_rand_stability_class.py b/test_regress/t/t_rand_stability_class.py
new file mode 100755
index 000000000..f989a35fb
--- /dev/null
+++ b/test_regress/t/t_rand_stability_class.py
@@ -0,0 +1,18 @@
+#!/usr/bin/env python3
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2025 by Wilson Snyder. This program is free software; you
+# can redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+# SPDX-License-Identifier: LGPL-3.0-only OR Artistic-2.0
+
+import vltest_bootstrap
+
+test.scenarios('simulator')
+
+test.compile()
+
+test.execute()
+
+test.passes()
diff --git a/test_regress/t/t_rand_stability_class.v b/test_regress/t/t_rand_stability_class.v
new file mode 100644
index 000000000..f139994ae
--- /dev/null
+++ b/test_regress/t/t_rand_stability_class.v
@@ -0,0 +1,33 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// This file ONLY is placed under the Creative Commons Public Domain, for
+// any use, without warranty, 2025 by Wilson Snyder.
+// SPDX-License-Identifier: CC0-1.0
+
+module t;
+  class Cls;
+    task test_srandom;
+      int i, j, k;
+      // $urandom is per-process thread, not affected by object stability/this.srandom(seed)
+      // "Each object maintains its own internal RNG, which is used exclusively by its randomize() method."
+      // THis was moved to t_rand_stability_class.v
+      this.srandom(1234);
+      i = $urandom;
+      this.srandom(1234);
+      j = $urandom;
+      this.srandom(1234);
+      k = $urandom;
+      if (i == j && i == k) $stop;  // Small chance randomly i == j, or j == k
+    endtask
+  endclass
+
+  Cls c1;
+
+  initial begin
+    c1 = new;
+    c1.test_srandom;
+
+    $write("*-* All Finished *-*\n");
+    $finish;
+  end
+endmodule