Correct copy in io_latency_probe:

Fixes: https://github.com/ripple/rippled/issues/2521

Copy ctor missed one member. Also added move since we have some rvalues
passed around here.

src/test/beast/beast_io_latency_probe_test.cpp

@@ -0,0 +1,120 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of rippled: https://github.com/ripple/rippled
+    Copyright (c) 2018 Ripple Labs Inc.
+
+    Permission to use, copy, modify, and/or distribute this software for any
+    purpose  with  or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+#include <ripple/beast/asio/io_latency_probe.h>
+#include <ripple/beast/unit_test.h>
+#include <beast/test/yield_to.hpp>
+#include <boost/asio/deadline_timer.hpp>
+#include <chrono>
+
+using namespace std::chrono_literals;
+
+class io_latency_probe_test :
+    public beast::unit_test::suite, public beast::test::enable_yield_to
+{
+    using MyTimer = boost::asio::basic_waitable_timer<std::chrono::steady_clock>;
+
+    struct test_sampler
+    {
+        beast::io_latency_probe <std::chrono::steady_clock> probe_;
+        std::vector<std::chrono::steady_clock::duration> durations_;
+
+        test_sampler (
+            std::chrono::milliseconds interval,
+            boost::asio::io_service& ios)
+            : probe_ (interval, ios)
+        {
+        }
+
+        void
+        start()
+        {
+            probe_.sample (std::ref(*this));
+        }
+
+        void
+        start_one()
+        {
+            probe_.sample_one (std::ref(*this));
+        }
+
+        void operator() (std::chrono::steady_clock::duration const& elapsed)
+        {
+            durations_.push_back(elapsed);
+        }
+    };
+
+    void
+    testSampleOne(boost::asio::yield_context& yield)
+    {
+        testcase << "sample one";
+        boost::system::error_code ec;
+        test_sampler io_probe {100ms, get_io_service()};
+        io_probe.start_one();
+        MyTimer timer {get_io_service(), 1s};
+        timer.async_wait(yield[ec]);
+        if(! BEAST_EXPECTS(! ec, ec.message()))
+            return;
+        BEAST_EXPECT(io_probe.durations_.size() == 1);
+        io_probe.probe_.cancel_async();
+    }
+
+    void
+    testSampleOngoing(boost::asio::yield_context& yield)
+    {
+        testcase << "sample ongoing";
+        boost::system::error_code ec;
+        test_sampler io_probe {99ms, get_io_service()};
+        io_probe.start();
+        MyTimer timer {get_io_service(), 1s};
+        timer.async_wait(yield[ec]);
+        if(! BEAST_EXPECTS(! ec, ec.message()))
+            return;
+        auto probes_seen = io_probe.durations_.size();
+        BEAST_EXPECTS(probes_seen >=9 && probes_seen <= 11,
+            std::string("probe count is ") + std::to_string(probes_seen));
+        io_probe.probe_.cancel_async();
+        // wait again in order to flush the remaining
+        // probes from the work queue
+        timer.expires_from_now(1s);
+        timer.async_wait(yield[ec]);
+    }
+
+    void
+    testCanceled(boost::asio::yield_context& yield)
+    {
+        testcase << "canceled";
+        test_sampler io_probe {100ms, get_io_service()};
+        io_probe.probe_.cancel_async();
+        except<std::logic_error>( [&io_probe](){ io_probe.start_one(); });
+        except<std::logic_error>( [&io_probe](){ io_probe.start(); });
+    }
+
+public:
+    void run () override
+    {
+        yield_to([&](boost::asio::yield_context& yield)
+        {
+            testSampleOne (yield);
+            testSampleOngoing (yield);
+            testCanceled (yield);
+        });
+    }
+};
+
+BEAST_DEFINE_TESTSUITE(io_latency_probe, asio, beast);

src/test/unity/beast_test_unity1.cpp

@@ -22,6 +22,7 @@
 #include <test/beast/beast_abstract_clock_test.cpp>
 #include <test/beast/beast_asio_error_test.cpp>
 #include <test/beast/beast_basic_seconds_clock_test.cpp>
+#include <test/beast/beast_io_latency_probe_test.cpp>
 #include <test/beast/beast_CurrentThreadName_test.cpp>
 #include <test/beast/beast_Debug_test.cpp>
 #include <test/beast/beast_Journal_test.cpp>