diff --git a/test/main.cpp b/test/main.cpp
index c50fafe..a2bc740 100644
--- a/test/main.cpp
+++ b/test/main.cpp
@@ -12,19 +12,19 @@ QVector<QObject*>* suites__ = nullptr;
 
 } // internal-linkage
 
-TestSuite::TestSuite(void) {
+TestSuite::TestSuite() {
     static struct __ {
         QVector<QObject*> suites_;
-        __(void) { suites__ = &suites_; }
+        __() { suites__ = &suites_; }
     } _;
     _.suites_ << this;
 }
 
-const char* TestSuite::name(void) const {
+const char* TestSuite::name() const {
     return "";
 }
 
-void TestSuite::initTestCase(void) {
+void TestSuite::initTestCase() {
     qDebug() << QString("#### Start: %1 ####").arg(name());
 }
 
diff --git a/test/test.h b/test/test.h
index 5fee10f..5fb915d 100644
--- a/test/test.h
+++ b/test/test.h
@@ -7,11 +7,11 @@ class TestSuite : public QObject
     Q_OBJECT
 
 public:
-    explicit TestSuite(void);
+    explicit TestSuite();
 
 protected:
-    virtual const char* name(void) const;
+    virtual const char* name() const;
 
 protected slots:
-    virtual void initTestCase(void);
+    virtual void initTestCase();
 };
diff --git a/test/test_circ.cpp b/test/test_circ.cpp
index 23860b3..a3603ad 100644
--- a/test/test_circ.cpp
+++ b/test/test_circ.cpp
@@ -17,21 +17,21 @@ namespace {
 class Unit : public TestSuite {
     Q_OBJECT
 
-    const char* name(void) const {
+    const char* name() const {
         return "test_circ";
     }
 
 private slots:
-    void initTestCase(void);
-    void cleanupTestCase(void);
+    void initTestCase();
+    void cleanupTestCase();
 
-    void test_inst(void);
-    void test_prod_cons_1v1(void);
-    void test_prod_cons_1v3(void);
-    void test_prod_cons_3v1(void);
-    void test_prod_cons_performance(void);
+    void test_inst();
+    void test_prod_cons_1v1();
+    void test_prod_cons_1v3();
+    void test_prod_cons_3v1();
+    void test_prod_cons_performance();
 
-    void test_queue(void);
+    void test_queue();
 } unit__;
 
 #include "test_circ.moc"
@@ -41,16 +41,16 @@ cq_t* cq__;
 
 constexpr int LoopCount = 1000000;
 
-void Unit::initTestCase(void) {
+void Unit::initTestCase() {
     TestSuite::initTestCase();
     cq__ = new cq_t;
 }
 
-void Unit::cleanupTestCase(void) {
+void Unit::cleanupTestCase() {
     delete cq__;
 }
 
-void Unit::test_inst(void) {
+void Unit::test_inst() {
     std::cout << "cq_t::head_size  = " << cq_t::head_size  << std::endl;
     std::cout << "cq_t::data_size  = " << cq_t::data_size  << std::endl;
     std::cout << "cq_t::elem_size  = " << cq_t::elem_size  << std::endl;
@@ -77,7 +77,7 @@ struct test_stopwatch {
     capo::stopwatch<> sw_;
     std::atomic_flag started_ = ATOMIC_FLAG_INIT;
 
-    void start(void) {
+    void start() {
         if (!started_.test_and_set()) {
             sw_.start();
         }
@@ -101,7 +101,7 @@ struct test_verify {
                 ];
     }
 
-    ~test_verify(void) {
+    ~test_verify() {
         delete [] list_;
     }
 
@@ -152,7 +152,7 @@ struct test_cq<ipc::circ::elem_array<D>> {
         ::new (ca) ca_t;
     }
 
-    cn_t connect(void) {
+    cn_t connect() {
         auto cur = ca_->cursor();
         ca_->connect();
         return cur;
@@ -201,7 +201,7 @@ struct test_cq<ipc::circ::queue<T>> {
         ::new (ca_) ca_t;
     }
 
-    cn_t connect(void) {
+    cn_t connect() {
         cn_t queue;
         [&] {
             queue.attach(ca_);
@@ -284,25 +284,25 @@ void test_prod_cons(T* cq) {
 }
 
 template <int N, int M, bool V = true, int Loops = LoopCount>
-void test_prod_cons(void) {
+void test_prod_cons() {
     test_prod_cons<N, M, V, Loops>(cq__);
 }
 
-void Unit::test_prod_cons_1v1(void) {
+void Unit::test_prod_cons_1v1() {
     test_prod_cons<1, 1>();
 }
 
-void Unit::test_prod_cons_1v3(void) {
+void Unit::test_prod_cons_1v3() {
     test_prod_cons<1, 3>();
 }
 
-void Unit::test_prod_cons_3v1(void) {
+void Unit::test_prod_cons_3v1() {
     test_prod_cons<3, 1>();
 }
 
 template <int P, int C>
 struct test_performance {
-    static void start(void) {
+    static void start() {
         test_performance<P - 1, C - 1>::start();
         test_prod_cons<P, C, false>();
     }
@@ -310,7 +310,7 @@ struct test_performance {
 
 template <int C>
 struct test_performance<1, C> {
-    static void start(void) {
+    static void start() {
         test_performance<1, C - 1>::start();
         test_prod_cons<1, C, false>();
     }
@@ -318,7 +318,7 @@ struct test_performance<1, C> {
 
 template <int P>
 struct test_performance<P, 1> {
-    static void start(void) {
+    static void start() {
         test_performance<P - 1, 1>::start();
         test_prod_cons<P, 1, false>();
     }
@@ -326,19 +326,19 @@ struct test_performance<P, 1> {
 
 template <>
 struct test_performance<1, 1> {
-    static void start(void) {
+    static void start() {
         test_prod_cons<1, 1, false>();
     }
 };
 
-void Unit::test_prod_cons_performance(void) {
+void Unit::test_prod_cons_performance() {
     test_performance<1 , 10>::start();
     test_performance<10, 1 >::start();
     test_performance<10, 10>::start();
     test_prod_cons  <3 , 3 >(); // test & verify
 }
 
-void Unit::test_queue(void) {
+void Unit::test_queue() {
     ipc::circ::queue<msg_t> queue;
     queue.push(1, 2);
     QVERIFY_EXCEPTION_THROWN(queue.pop(), std::exception);
diff --git a/test/test_ipc.cpp b/test/test_ipc.cpp
index 31d1748..2f199a7 100644
--- a/test/test_ipc.cpp
+++ b/test/test_ipc.cpp
@@ -6,17 +6,18 @@ namespace {
 class Unit : public TestSuite {
     Q_OBJECT
 
-    const char* name(void) const {
+    const char* name() const {
         return "test_ipc";
     }
 
 private slots:
-    void test_send_recv(void);
+    void test_send_recv();
+    void test_rw_lock();
 } unit__;
 
 #include "test_ipc.moc"
 
-void Unit::test_send_recv(void) {
+void Unit::test_send_recv() {
     auto h = ipc::connect("my-ipc");
     QVERIFY(h != nullptr);
     char data[] = "hello ipc!";
@@ -26,4 +27,8 @@ void Unit::test_send_recv(void) {
     ipc::disconnect(h);
 }
 
+void Unit::test_rw_lock() {
+
+}
+
 } // internal-linkage
diff --git a/test/test_shm.cpp b/test/test_shm.cpp
index d49dc60..8d096e0 100644
--- a/test/test_shm.cpp
+++ b/test/test_shm.cpp
@@ -12,23 +12,23 @@ namespace {
 class Unit : public TestSuite {
     Q_OBJECT
 
-    const char* name(void) const {
+    const char* name() const {
         return "test_shm";
     }
 
 private slots:
-    void test_acquire(void);
-    void test_release(void);
-    void test_get(void);
-    void test_hello(void);
-    void test_mt(void);
+    void test_acquire();
+    void test_release();
+    void test_get();
+    void test_hello();
+    void test_mt();
 } unit__;
 
 #include "test_shm.moc"
 
 handle shm_hd__;
 
-void Unit::test_acquire(void) {
+void Unit::test_acquire() {
     QVERIFY(!shm_hd__.valid());
 
     QVERIFY(shm_hd__.acquire("my-test-1", 1024));
@@ -44,13 +44,13 @@ void Unit::test_acquire(void) {
     QCOMPARE(shm_hd__.name(), "my-test-3");
 }
 
-void Unit::test_release(void) {
+void Unit::test_release() {
     QVERIFY(shm_hd__.valid());
     shm_hd__.release();
     QVERIFY(!shm_hd__.valid());
 }
 
-void Unit::test_get(void) {
+void Unit::test_get() {
     QVERIFY(shm_hd__.get() == nullptr);
     QVERIFY(shm_hd__.acquire("my-test", 1024));
 
@@ -66,7 +66,7 @@ void Unit::test_get(void) {
     QVERIFY(mem == shm_hd__.get());
 }
 
-void Unit::test_hello(void) {
+void Unit::test_hello() {
     auto mem = shm_hd__.get();
     QVERIFY(mem != nullptr);
 
@@ -76,7 +76,7 @@ void Unit::test_hello(void) {
     QCOMPARE((char*)shm_hd__.get(), hello);
 }
 
-void Unit::test_mt(void) {
+void Unit::test_mt() {
     std::thread {
         [] {
             handle shm_mt(shm_hd__.name(), shm_hd__.size());