From 7718a63b24cf8dc35758a5b9020acbf993dc2292 Mon Sep 17 00:00:00 2001
From: mutouyun <orz@orzz.org>
Date: Wed, 21 Nov 2018 21:38:29 +0800
Subject: [PATCH] print spent time & performance

---
 src/circ_queue.h         |   5 +-
 test/stopwatch.hpp       | 109 +++++++++++++++++++++++++++++++++++++++
 test/test_circ_queue.cpp |  24 +++++----
 3 files changed, 125 insertions(+), 13 deletions(-)
 create mode 100644 test/stopwatch.hpp

diff --git a/src/circ_queue.h b/src/circ_queue.h
index 4167308..1485503 100644
--- a/src/circ_queue.h
+++ b/src/circ_queue.h
@@ -62,10 +62,7 @@ public:
         auto st = begin() + id(cr_.load(std::memory_order_relaxed));
         do {
             // check remain count of consumers
-            if (st->head_.load(std::memory_order_acquire)) {
-                std::this_thread::yield();
-            }
-            else {
+            if (!st->head_.load(std::memory_order_acquire)) {
                 st->head_.store(conn_count());
                 break;
             }
diff --git a/test/stopwatch.hpp b/test/stopwatch.hpp
new file mode 100644
index 0000000..1e96dcb
--- /dev/null
+++ b/test/stopwatch.hpp
@@ -0,0 +1,109 @@
+/*
+    The Capo Library
+    Code covered by the MIT License
+
+    Author: mutouyun (http://orzz.org)
+*/
+
+#pragma once
+
+#include <chrono>   // std::chrono
+#include <array>    // std::array
+#include <utility>  // std::pair, std::declval
+#include <cstddef>  // size_t
+
+namespace capo {
+
+////////////////////////////////////////////////////////////////
+/// Stopwatch - can store multiple sets of time
+////////////////////////////////////////////////////////////////
+
+template <size_t CountN = 1, class ClockT = std::chrono::steady_clock>
+class stopwatch : public ClockT
+{
+    using base_t = ClockT;
+
+    static_assert(CountN > 0, "The count must be greater than 0");
+
+public:
+    using rep        = typename ClockT::rep;
+    using period     = typename ClockT::period;
+    using duration   = typename ClockT::duration;
+    using time_point = typename ClockT::time_point;
+
+private:
+    using pair_t = std::pair<time_point/*start*/, time_point/*paused*/>;
+
+    std::array<pair_t, CountN> points_;
+    bool is_stopped_ = true;
+
+public:
+    stopwatch(bool start_watch = false)
+    {
+        if (start_watch) start();
+    }
+
+public:
+    bool is_stopped(void) const
+    {
+        return is_stopped_;
+    }
+
+    template <size_t N = 0>
+    bool is_paused(void) const
+    {
+        return (points_[N].second != points_[N].first);
+    }
+
+    template <size_t N = 0>
+    duration elapsed(void)
+    {
+        if (is_stopped())
+            return duration::zero();
+        else
+        if (is_paused<N>())
+            return (points_[N].second - points_[N].first);
+        else
+            return ClockT::now() - points_[N].first;
+    }
+
+    template <typename ToDur, size_t N = 0>
+    auto elapsed(void) -> decltype(std::declval<ToDur>().count())
+    {
+        return std::chrono::duration_cast<ToDur>(elapsed<N>()).count();
+    }
+
+    template <size_t N = 0>
+    void pause(void)
+    {
+        points_[N].second = ClockT::now();
+    }
+
+    template <size_t N = 0>
+    void restart(void)
+    {
+        points_[N].second = points_[N].first =
+            ClockT::now() - (points_[N].second - points_[N].first);
+    }
+
+    void start(void)
+    {
+        time_point now = ClockT::now();
+        for (auto& pt : points_)
+        {
+            pt.second = pt.first = now - (pt.second - pt.first);
+        }
+        is_stopped_ = false;
+    }
+
+    void stop(void)
+    {
+        for (auto& pt : points_)
+        {
+            pt.second = pt.first;
+        }
+        is_stopped_ = true;
+    }
+};
+
+} // namespace capo
diff --git a/test/test_circ_queue.cpp b/test/test_circ_queue.cpp
index 40a97f5..618d453 100644
--- a/test/test_circ_queue.cpp
+++ b/test/test_circ_queue.cpp
@@ -2,9 +2,11 @@
 #include <string>
 #include <type_traits>
 #include <memory>
+#include <new>
 
 #include "circ_queue.h"
 #include "test.h"
+#include "stopwatch.hpp"
 
 namespace {
 
@@ -32,8 +34,8 @@ void Unit::test_inst(void) {
 }
 
 void Unit::test_producer(void) {
-    cq__ = new cq_t;
-    std::thread consumers[3];
+    ::new (cq__) cq_t;
+    std::thread consumers[1];
 
     for (auto& c : consumers) {
         c = std::thread{[&c] {
@@ -48,11 +50,8 @@ void Unit::test_producer(void) {
             do {
                 while (cur != cq__->cursor()) {
                     int d = *static_cast<const int*>(cq__->get(cur));
-//                    std::cout << &c << ": cur = " << (int)cur << ", " << d << std::endl;
-                    if (d < 0) {
-                        return;
-                    }
-                    else QCOMPARE(d, i);
+                    if (d < 0) return;
+                    QCOMPARE(d, i);
                     ++cur;
                     ++i;
                 }
@@ -63,20 +62,27 @@ void Unit::test_producer(void) {
     while (cq__->conn_count() != std::extent<decltype(consumers)>::value) {
         std::this_thread::yield();
     }
+    capo::stopwatch<> sw;
+    constexpr static int loops = 1000000;
+
     std::cout << "start producer..." << std::endl;
-    for (int i = 0; i < 1000; ++i) {
+    sw.start();
+    for (int i = 0; i < loops; ++i) {
         auto d = static_cast<int*>(cq__->acquire());
         *d = i;
         cq__->commit();
     }
     auto d = static_cast<int*>(cq__->acquire());
     *d = -1;
-    std::cout << "put: quit..." << std::endl;
     cq__->commit();
 
     for (auto& c : consumers) {
         c.join();
     }
+
+    auto ts = sw.elapsed<std::chrono::microseconds>();
+    std::cout << "time spent : " << (ts / 1000) << " ms" << std::endl;
+    std::cout << "performance: " << (double(ts) / double(loops)) << " us/msg" << std::endl;
 }
 
 } // internal-linkage