verilator/test_regress/t/t_mailbox_concurrent.v

// DESCRIPTION: Verilator: Verilog Test module
//
// This file ONLY is placed under the Creative Commons Public Domain.
// SPDX-FileCopyrightText: 2024 Liam Braun
// SPDX-License-Identifier: CC0-1.0

module t;
  mailbox #(int) m;

  task automatic test_get;
    int v;
    m.get(v);
    // Only one thread should be here at a time (mailbox empty)
    $display("mailbox read %0t", $time);
    #1;
    m.put(v);
  endtask

  task automatic test_put;
    int v;
    m.put(42);
    // Only one thread should be here at a time (mailbox full)
    $display("mailbox write %0t", $time);
    #1;
    m.get(v);
  endtask

  initial begin
    m = new(1);
    m.put(42);

    fork
      test_get();
      test_get();
      test_get();
    join

    m = new(1);

    fork
      test_put();
      test_put();
      test_put();
    join

    $write("*-* All Finished *-*\n");
    $finish;
  end
endmodule