Merge #2871

Fake work for resolution models testing.

(The correct version of branch now)

configure.ac

@@ -1201,6 +1201,7 @@ AC_CONFIG_FILES([Makefile
                  src/bin/dhcp4/tests/Makefile
                  src/bin/resolver/Makefile
                  src/bin/resolver/tests/Makefile
+                 src/bin/resolver/bench/Makefile
                  src/bin/sysinfo/Makefile
                  src/bin/sockcreator/Makefile
                  src/bin/sockcreator/tests/Makefile

src/bin/resolver/Makefile.am

@@ -1,4 +1,4 @@
-SUBDIRS = . tests
+SUBDIRS = . tests bench
 
 AM_CPPFLAGS = -I$(top_srcdir)/src/lib -I$(top_builddir)/src/lib
 AM_CPPFLAGS += -I$(top_srcdir)/src/bin -I$(top_builddir)/src/bin

src/bin/resolver/bench/Makefile.am

@@ -0,0 +1,25 @@
+AM_CPPFLAGS = -I$(top_srcdir)/src/lib -I$(top_builddir)/src/lib
+AM_CPPFLAGS += -I$(top_builddir)/src/lib/dns -I$(top_srcdir)/src/bin
+AM_CPPFLAGS += -I$(top_builddir)/src/lib/cc
+AM_CPPFLAGS += -I$(top_builddir)/src/bin/resolver
+AM_CPPFLAGS += $(BOOST_INCLUDES)
+
+AM_CXXFLAGS = $(B10_CXXFLAGS)
+
+if USE_STATIC_LINK
+AM_LDFLAGS = -static
+endif
+
+CLEANFILES = *.gcno *.gcda
+
+noinst_PROGRAMS = resolver-bench
+
+resolver_bench_SOURCES = main.cc
+resolver_bench_SOURCES += fake_resolution.h fake_resolution.cc
+resolver_bench_SOURCES += dummy_work.h dummy_work.cc
+resolver_bench_SOURCES += naive_resolver.h naive_resolver.cc
+
+resolver_bench_LDADD  = $(GTEST_LDADD)
+resolver_bench_LDADD += $(top_builddir)/src/lib/exceptions/libb10-exceptions.la
+resolver_bench_LDADD += $(top_builddir)/src/lib/asiolink/libb10-asiolink.la
+

src/bin/resolver/bench/dummy_work.cc

@@ -0,0 +1,28 @@
+// Copyright (C) 2013  Internet Systems Consortium, Inc. ("ISC")
+//
+// 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 ISC DISCLAIMS ALL WARRANTIES WITH
+// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+// AND FITNESS.  IN NO EVENT SHALL ISC 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 <resolver/bench/dummy_work.h>
+
+namespace isc {
+namespace resolver {
+namespace bench {
+
+void
+dummy_work() {
+    // Function left intentonally blank.
+};
+
+}
+}
+}

src/bin/resolver/bench/dummy_work.h

@@ -0,0 +1,36 @@
+// Copyright (C) 2013  Internet Systems Consortium, Inc. ("ISC")
+//
+// 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 ISC DISCLAIMS ALL WARRANTIES WITH
+// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+// AND FITNESS.  IN NO EVENT SHALL ISC 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.
+
+#ifndef DUMMY_WORK_H
+#define DUMMY_WORK_H
+
+namespace isc {
+namespace resolver {
+namespace bench {
+
+/// \brief An empty function.
+///
+/// An empty function, to fill the CPU with something during the benchmark.
+/// It is expected to be called many times by whatever simulates doing some
+/// real CPU-bound work.
+///
+/// It is defined in separate translation unit, so the compiler does not
+/// know it is empty and can't optimise the call out.
+void dummy_work();
+
+}
+}
+}
+
+#endif

src/bin/resolver/bench/fake_resolution.cc

@@ -0,0 +1,172 @@
+// Copyright (C) 2013  Internet Systems Consortium, Inc. ("ISC")
+//
+// 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 ISC DISCLAIMS ALL WARRANTIES WITH
+// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+// AND FITNESS.  IN NO EVENT SHALL ISC 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 <resolver/bench/fake_resolution.h>
+#include <resolver/bench/dummy_work.h>
+
+#include <asiolink/interval_timer.h>
+
+#include <boost/bind.hpp>
+#include <boost/foreach.hpp>
+#include <algorithm>
+#include <cstdlib>
+
+namespace isc {
+namespace resolver {
+namespace bench {
+
+// Parameters of the generated queries.
+// How much work is each operation?
+const size_t parse_size = 100000;
+const size_t render_size = 100000;
+const size_t send_size = 1000;
+const size_t cache_read_size = 10000;
+const size_t cache_write_size = 10000;
+// How large a change is to terminate in this iteration (either by getting
+// the complete answer, or by finding it in the cache). With 0.5, half the
+// queries are found in the cache directly. Half of the rest needs just one
+// upstream query. Etc.
+const float chance_complete = 0.5;
+// Number of milliseconds an upstream query can take. It picks a random number
+// in between.
+const size_t upstream_time_min = 2;
+const size_t upstream_time_max = 50;
+
+FakeQuery::FakeQuery(FakeInterface& interface) :
+    interface_(&interface),
+    outstanding_(false)
+{
+    // Schedule what tasks are needed.
+    // First, parse the query
+    steps_.push_back(Step(Compute, parse_size));
+    // Look into the cache if it is there
+    steps_.push_back(Step(CacheRead, cache_read_size));
+    while ((1.0 * random()) / RAND_MAX > chance_complete) {
+        // Needs another step of recursion. Render the upstream query.
+        steps_.push_back(Step(Compute, render_size));
+        // Send it and wait for the answer.
+        steps_.push_back(Step(Upstream, upstream_time_min +
+                              (random() *
+                               (upstream_time_max - upstream_time_min) /
+                               RAND_MAX)));
+        // After it comes, parse the answer and store it in the cache.
+        steps_.push_back(Step(Compute, parse_size));
+        steps_.push_back(Step(CacheWrite, cache_write_size));
+    }
+    // Last, render the answer and send it.
+    steps_.push_back(Step(Compute, render_size));
+    steps_.push_back(Step(Send, send_size));
+    // Reverse it, so we can pop_back the tasks as we work on them.
+    std::reverse(steps_.begin(), steps_.end());
+}
+
+void
+FakeQuery::performTask(const StepCallback& callback) {
+    // nextTask also does all the sanity checking we need.
+    if (nextTask() == Upstream) {
+        outstanding_ = true;
+        interface_->scheduleUpstreamAnswer(this, callback,
+                                           steps_.back().second);
+        steps_.pop_back();
+    } else {
+        for (size_t i = 0; i < steps_.back().second; ++i) {
+            dummy_work();
+        }
+        steps_.pop_back();
+        callback();
+    }
+}
+
+FakeInterface::FakeInterface(size_t query_count) :
+    queries_(query_count)
+{
+    BOOST_FOREACH(FakeQueryPtr& query, queries_) {
+        query = FakeQueryPtr(new FakeQuery(*this));
+    }
+}
+
+void
+FakeInterface::processEvents() {
+    service_.run_one();
+}
+
+namespace {
+
+void
+processDone(bool* flag) {
+    *flag = true;
+}
+
+}
+
+FakeQueryPtr
+FakeInterface::receiveQuery() {
+    // Handle all the events that are already scheduled.
+    // As processEvents blocks until an event happens and we want to terminate
+    // if there are no events, we do a small trick. We post an event to the end
+    // of the queue and work until it is found. This should process all the
+    // events that were there already.
+    bool processed = false;
+    service_.post(boost::bind(&processDone, &processed));
+    while (!processed) {
+        processEvents();
+    }
+
+    // Now, look if there are more queries to return.
+    if (queries_.empty()) {
+        return (FakeQueryPtr());
+    } else {
+        // Take from the back. The order doesn't matter and it's faster from
+        // there.
+        FakeQueryPtr result(queries_.back());
+        queries_.pop_back();
+        return (result);
+    }
+}
+
+class FakeInterface::UpstreamQuery {
+public:
+    UpstreamQuery(FakeQuery* query, const FakeQuery::StepCallback& callback,
+                  const boost::shared_ptr<asiolink::IntervalTimer> timer) :
+        query_(query),
+        callback_(callback),
+        timer_(timer)
+    {}
+    void trigger() {
+        query_->outstanding_ = false;
+        callback_();
+        // We are not needed any more.
+        delete this;
+    }
+private:
+    FakeQuery* const query_;
+    const FakeQuery::StepCallback callback_;
+    // Just to hold it alive before the callback is called.
+    const boost::shared_ptr<asiolink::IntervalTimer> timer_;
+};
+
+void
+FakeInterface::scheduleUpstreamAnswer(FakeQuery* query,
+                                      const FakeQuery::StepCallback& callback,
+                                      size_t msec)
+{
+    const boost::shared_ptr<asiolink::IntervalTimer>
+        timer(new asiolink::IntervalTimer(service_));
+    UpstreamQuery* q(new UpstreamQuery(query, callback, timer));
+    timer->setup(boost::bind(&UpstreamQuery::trigger, q), msec);
+}
+
+}
+}
+}

src/bin/resolver/bench/fake_resolution.h

@@ -0,0 +1,221 @@
+// Copyright (C) 2013  Internet Systems Consortium, Inc. ("ISC")
+//
+// 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 ISC DISCLAIMS ALL WARRANTIES WITH
+// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+// AND FITNESS.  IN NO EVENT SHALL ISC 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.
+
+#ifndef FAKE_RESOLUTION_H
+#define FAKE_RESOLUTION_H
+
+#include <exceptions/exceptions.h>
+#include <asiolink/io_service.h>
+
+#include <boost/function.hpp>
+#include <boost/shared_ptr.hpp>
+
+#include <utility>
+#include <vector>
+
+namespace isc {
+namespace resolver {
+namespace bench {
+
+/// \brief The kind of task a FakeQuery might want to perform.
+///
+/// The benchmark should examine which kind of task the query needs to perform
+/// to progress forward. According to the task, some resources might need to be
+/// locked, something re-scheduled, or such.
+enum Task {
+    /// \brief Some CPU-bound computation.
+    ///
+    /// The query needs to do some computation without any shared resources.
+    /// This might be parsing or rendering of the query, verification of
+    /// signatures, etc.
+    Compute,
+    /// \brief The query needs to read data from cache.
+    CacheRead,
+    /// \brief The query needs to modify the cache.
+    CacheWrite,
+    /// \brief A response is to be sent.
+    ///
+    /// This needs to access the interface/socket. If the socket is shared
+    /// between threads, it might need to lock it.
+    Send,
+    /// \brief An answer from upstream server is needed.
+    ///
+    /// The query needs to send a query to some authoritative server and wait
+    /// for the answer. Something might need to be locked (or not, depending
+    /// on the architecture of the thing that sends and receives). Also, the
+    /// task will not complete immediately, the callback of performTask
+    /// will be called at later time.
+    Upstream
+};
+
+class FakeInterface;
+
+/// \brief Imitation of the work done to resolve a query.
+///
+/// An object of this class represents some fake work that should look like
+/// the work needed to perform resolution of one query. No real work is done,
+/// but several steps are scheduled, with characteristics hopefully
+/// corresponding to steps of the real query.
+///
+/// The idea is that benchmark will repeatedly check if the query is done.
+/// If not, it examines the next task by calling nextTask(). Depending on
+/// the result, it'd lock or prepare any shared resources. After that, it'd
+/// call performTask() to do the task. Once the query calls the callback
+/// passed, it can proceed to the next step.
+///
+/// See naive_resolver.cc for example code how this could be done.
+class FakeQuery {
+private:
+    // The queries come only through an interface. Don't let others create.
+    friend class FakeInterface;
+    /// \brief Constructor
+    FakeQuery(FakeInterface& interface);
+public:
+    /// \brief Is work on the query completely done?
+    ///
+    /// If this returns true, do not call performTask or nextTask any more.
+    /// The resolution is done.
+    ///
+    /// \throw isc::InvalidOperation if upstream query is still in progress.
+    bool done() const {
+        if (outstanding_) {
+            isc_throw(isc::InvalidOperation, "Upstream query outstanding");
+        }
+        return (steps_.empty());
+    }
+    /// \brief Callback to signify a task has been performed.
+    typedef boost::function<void()> StepCallback;
+    /// \brief Perform next step in the resolution.
+    ///
+    /// Do whatever is needed to be done for the next step of resolution.
+    /// Once the step is done, the callback is called.
+    ///
+    /// The callback is usually called from within this call. However, in
+    /// the case when the nextTask() returned `Upstream`, the call to the
+    /// callback is delayed for some period of time after the method
+    /// returns.
+    ///
+    /// \throw isc::InvalidOperation if it is called when done() is true, or
+    ///     if an upstream query is still in progress (performTask was called
+    ///     before and the callback was not called by the query yet).
+    void performTask(const StepCallback& callback);
+    /// \brief Examine the kind of the next resolution process.
+    ///
+    /// Call this to know what kind of task will performTask do next.
+    ///
+    /// \throw isc::InvalidOperation if it is called when done() is true, or
+    ///     if an upstream query is still in progress (performTask was called
+    ///     before and the callback was not called by the query yet).
+    Task nextTask() const {
+        // Will check for outstanding_ internally too
+        if (done()) {
+            isc_throw(isc::InvalidOperation, "We are done, no more tasks");
+        }
+        return (steps_.back().first);
+    }
+    /// \brief Move network communication to different interface.
+    ///
+    /// By default, a query does all the "communication" on the interface
+    /// it was born on. This may be used to move a query from one interface
+    /// to another.
+    ///
+    /// You don't have to lock either of the interfaces to do so, this
+    /// only switches the data in the query.
+    ///
+    /// \throw isc::InvalidOperation if it is called while an upstream query
+    ///     is in progress.
+    void migrateTo(FakeInterface& dst_interface) {
+        if (outstanding_) {
+            isc_throw(isc::InvalidOperation,
+                      "Can't migrate in the middle of query");
+        }
+        interface_ = &dst_interface;
+    }
+private:
+    // The scheduled steps for this task.
+    typedef std::pair<Task, size_t> Step;
+    // The scheduled steps. Reversed (first to be done at the end), so we can
+    // pop_back() the completed steps.
+    std::vector<Step> steps_;
+    // The interface to schedule timeouts on.
+    FakeInterface* interface_;
+    // Is an upstream query outstanding?
+    bool outstanding_;
+};
+
+typedef boost::shared_ptr<FakeQuery> FakeQueryPtr;
+
+/// \brief An imitation of interface for receiving queries.
+///
+/// This is effectively a little bit smarter factory for queries. You can
+/// request a new query from it, or let process events (incoming answers).
+///
+/// It contains its own event loop. If the benchmark has more threads, have
+/// one in each of the threads (if the threads ever handles network
+/// communication -- if it accepts queries, sends answers or does upstream
+/// queries).
+///
+/// If the model simulated would share the same interface between multiple
+/// threads, it is better to have one in each thread as well, but lock
+/// access to receiveQuery() so only one is used at once (no idea what happens
+/// if ASIO loop is accessed from multiple threads).
+///
+/// Note that the creation of the queries is not thread safe (due to
+/// the random() function inside). The interface generates all its queries
+/// in advance, on creation time. But you need to create all the needed
+/// interfaces from single thread and then distribute them to your threads.
+class FakeInterface {
+public:
+    /// \brief Constructor
+    ///
+    /// Initiarile the interface and create query_count queries for the
+    /// benchmark. They will be handed out one by one with receiveQuery().
+    FakeInterface(size_t query_count);
+    /// \brief Wait for answers from upstream servers.
+    ///
+    /// Wait until at least one "answer" comes from the remote server. This
+    /// will effectively block the calling thread until it is time to call
+    /// a callback of performTask.
+    ///
+    /// It is not legal to call it without any outstanding upstream queries
+    /// on this interface. However, the situation is not explicitly checked.
+    ///
+    /// \note Due to internal implementation, it is not impossible no or more
+    ///    than one callbacks to be called from within this method.
+    void processEvents();
+    /// \brief Accept another query.
+    ///
+    /// Generate a new fake query to resolve.
+    ///
+    /// This method might call callbacks of other queries waiting for upstream
+    /// answer.
+    ///
+    /// This returns a NULL pointer when there are no more queries to answer
+    /// (the number designated for the benchmark was reached).
+    FakeQueryPtr receiveQuery();
+private:
+    class UpstreamQuery;
+    friend class FakeQuery;
+    void scheduleUpstreamAnswer(FakeQuery* query,
+                                const FakeQuery::StepCallback& callback,
+                                size_t msec);
+    asiolink::IOService service_;
+    std::vector<FakeQueryPtr> queries_;
+};
+
+}
+}
+}
+
+#endif

src/bin/resolver/bench/main.cc

@@ -0,0 +1,27 @@
+// Copyright (C) 2013  Internet Systems Consortium, Inc. ("ISC")
+//
+// 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 ISC DISCLAIMS ALL WARRANTIES WITH
+// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+// AND FITNESS.  IN NO EVENT SHALL ISC 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 <resolver/bench/naive_resolver.h>
+
+#include <bench/benchmark.h>
+
+const size_t count = 1000; // TODO: We may want to read this from argv.
+
+int main(int, const char**) {
+    // Run the naive implementation
+    isc::resolver::bench::NaiveResolver naive_resolver(count);
+    isc::bench::BenchMark<isc::resolver::bench::NaiveResolver>
+        (1, naive_resolver, true);
+    return 0;
+}

src/bin/resolver/bench/naive_resolver.cc

@@ -0,0 +1,66 @@
+// Copyright (C) 2013  Internet Systems Consortium, Inc. ("ISC")
+//
+// 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 ISC DISCLAIMS ALL WARRANTIES WITH
+// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+// AND FITNESS.  IN NO EVENT SHALL ISC 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 <resolver/bench/naive_resolver.h>
+
+#include <cassert>
+#include <boost/bind.hpp>
+
+namespace isc {
+namespace resolver {
+namespace bench {
+
+NaiveResolver::NaiveResolver(size_t query_count) :
+    interface_(query_count),
+    processed_(false)
+{}
+
+namespace {
+
+void
+stepDone(bool* flag) {
+    *flag = true;
+}
+
+}
+
+size_t
+NaiveResolver::run() {
+    assert(!processed_);
+    size_t count = 0;
+    FakeQueryPtr query;
+    // Process a query at a time. As the previous is already handled, the
+    // receiveQuery may never trigger other events.
+    while ((query = interface_.receiveQuery())) {
+        // Handle each step
+        while (!query->done()) {
+            bool done = false; // This step is not yet done.
+            // If there were more queries/threads/whatever, we would examine
+            // the query->nextTask() and lock or prepare resources accordingly.
+            // But as there's just one, we simply do the task, without caring.
+            query->performTask(boost::bind(&stepDone, &done));
+            // We may need to wait for the upstream query.
+            while (!done) {
+                interface_.processEvents();
+            }
+        }
+        count ++;
+    }
+    processed_ = true;
+    return (count);
+}
+
+}
+}
+}

src/bin/resolver/bench/naive_resolver.h

@@ -0,0 +1,44 @@
+// Copyright (C) 2013  Internet Systems Consortium, Inc. ("ISC")
+//
+// 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 ISC DISCLAIMS ALL WARRANTIES WITH
+// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+// AND FITNESS.  IN NO EVENT SHALL ISC 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.
+
+#ifndef RESOLVER_BENCH_NAIVE_H
+#define RESOLVER_BENCH_NAIVE_H
+
+#include <resolver/bench/fake_resolution.h>
+
+namespace isc {
+namespace resolver {
+namespace bench {
+
+/// \brief Naive implementation of resolver for the benchmark
+///
+/// This is here mostly to show how to implement the other benchmark
+/// implementations. Look at the code inside how to use the fake
+/// resolution.
+class NaiveResolver {
+public:
+    /// \brief Constructor. Initializes the data.
+    NaiveResolver(size_t query_count);
+    /// \brief Run the resolution.
+    size_t run();
+private:
+    FakeInterface interface_;
+    bool processed_;
+};
+
+}
+}
+}
+
+#endif

src/lib/asiolink/io_service.cc

@@ -1,4 +1,4 @@
-// Copyright (C) 2011  Internet Systems Consortium, Inc. ("ISC")
+// Copyright (C) 2011,2013  Internet Systems Consortium, Inc. ("ISC")
 //
 // Permission to use, copy, modify, and/or distribute this software for any
 // purpose with or without fee is hereby granted, provided that the above
@@ -63,6 +63,9 @@ public:
     /// It will eventually be removed once the wrapper interface is
     /// generalized.
     asio::io_service& get_io_service() { return io_service_; };
+    void post(const boost::function<void ()>& callback) {
+        io_service_.post(callback);
+    }
 private:
     asio::io_service io_service_;
     asio::io_service::work work_;
@@ -96,5 +99,10 @@ IOService::get_io_service() {
     return (io_impl_->get_io_service());
 }
 
+void
+IOService::post(const boost::function<void ()>& callback) {
+    return (io_impl_->post(callback));
+}
+
 } // namespace asiolink
 } // namespace isc

src/lib/asiolink/io_service.h

@@ -1,4 +1,4 @@
-// Copyright (C) 2011  Internet Systems Consortium, Inc. ("ISC")
+// Copyright (C) 2011,2013  Internet Systems Consortium, Inc. ("ISC")
 //
 // Permission to use, copy, modify, and/or distribute this software for any
 // purpose with or without fee is hereby granted, provided that the above
@@ -15,6 +15,8 @@
 #ifndef ASIOLINK_IO_SERVICE_H
 #define ASIOLINK_IO_SERVICE_H 1
 
+#include <boost/function.hpp>
+
 namespace asio {
     class io_service;
 }
@@ -70,6 +72,17 @@ public:
     /// generalized.
     asio::io_service& get_io_service();
 
+    /// \brief Post a callback to the end of the queue.
+    ///
+    /// Requests the callback be called sometime later. It is not guaranteed
+    /// by the underlying asio, but it can reasonably be expected the callback
+    /// is put to the end of the callback queue. It is not called from within
+    /// this function.
+    ///
+    /// It may be used to implement "background" work, for example (doing stuff
+    /// by small bits that are called from time to time).
+    void post(const boost::function<void ()>& callback);
+
 private:
     IOServiceImpl* io_impl_;
 };

src/lib/asiolink/tests/Makefile.am

@@ -33,6 +33,7 @@ run_unittests_SOURCES += tcp_endpoint_unittest.cc
 run_unittests_SOURCES += tcp_socket_unittest.cc
 run_unittests_SOURCES += udp_endpoint_unittest.cc
 run_unittests_SOURCES += udp_socket_unittest.cc
+run_unittests_SOURCES += io_service_unittest.cc
 
 run_unittests_CPPFLAGS = $(AM_CPPFLAGS) $(GTEST_INCLUDES)
 

src/lib/asiolink/tests/io_service_unittest.cc

@@ -0,0 +1,48 @@
+// Copyright (C) 2013  Internet Systems Consortium, Inc. ("ISC")
+//
+// 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 ISC DISCLAIMS ALL WARRANTIES WITH
+// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+// AND FITNESS.  IN NO EVENT SHALL ISC 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 <asiolink/io_service.h>
+
+#include <gtest/gtest.h>
+#include <boost/bind.hpp>
+#include <vector>
+
+using namespace isc::asiolink;
+
+namespace {
+
+void
+postedEvent(std::vector<int>* destination, int value) {
+    destination->push_back(value);
+}
+
+// Check the posted events are called, in the same order they are posted.
+TEST(IOService, post) {
+    std::vector<int> called;
+    IOService service;
+    // Post two events
+    service.post(boost::bind(&postedEvent, &called, 1));
+    service.post(boost::bind(&postedEvent, &called, 2));
+    // They have not yet been called
+    EXPECT_TRUE(called.empty());
+    // Process two events
+    service.run_one();
+    service.run_one();
+    // Both events were called in the right order
+    ASSERT_EQ(2, called.size());
+    EXPECT_EQ(1, called[0]);
+    EXPECT_EQ(2, called[1]);
+}
+
+}

src/lib/bench/benchmark.h

@@ -1,4 +1,4 @@
-// Copyright (C) 2010  Internet Systems Consortium, Inc. ("ISC")
+// Copyright (C) 2010,2013  Internet Systems Consortium, Inc. ("ISC")
 //
 // Permission to use, copy, modify, and/or distribute this software for any
 // purpose with or without fee is hereby granted, provided that the above
@@ -93,7 +93,7 @@ namespace bench {
 ///        vector<int>::const_iterator end_key = keys_.end();
 ///        for (iter = keys_.begin(); iter != end_key; ++iter) {
 ///            data_.find(*iter);
-///        }        
+///        }
 ///        return (keys_.size());
 ///    }
 ///    const set<int>& data_;