ruby: remove the cpu assumptions for the random tester

configs/example/ruby_random_test.py

@@ -90,8 +90,7 @@ if buildEnv['PROTOCOL'] == 'MOESI_hammer':
 
 tester = RubyTester(check_flush = check_flush,
                     checks_to_complete = options.checks,
-                    wakeup_frequency = options.wakeup_freq,
-                    num_cpus = options.num_cpus)
+                    wakeup_frequency = options.wakeup_freq)
 
 #
 # Create the M5 system.  Note that the Memory Object isn't
@@ -104,6 +103,8 @@ Ruby.create_system(options, system)
 
 assert(options.num_cpus == len(system.ruby._cpu_ruby_ports))
 
+tester.num_cpus = len(system.ruby._cpu_ruby_ports)
+
 #
 # The tester is most effective when randomization is turned on and
 # artifical delay is randomly inserted on messages

src/cpu/testers/rubytest/CheckTable.cc

@@ -106,6 +106,7 @@ CheckTable::addCheck(const Address& address)
 Check*
 CheckTable::getRandomCheck()
 {
+    assert(m_check_vector.size() > 0);
     return m_check_vector[random() % m_check_vector.size()];
 }