[#891,!592] make StatsMgr thread safe

src/lib/stats/context.cc

@@ -7,39 +7,111 @@
 #include <config.h>
 
 #include <stats/context.h>
+#include <util/multi_threading_mgr.h>
 #include <map>
 
+using namespace std;
+using namespace isc::data;
+using namespace isc::util;
+
 namespace isc {
 namespace stats {
 
 ObservationPtr StatContext::get(const std::string& name) const {
-    std::map<std::string, ObservationPtr>::const_iterator obs = stats_.find(name);
-    if (obs == stats_.end()) {
-        return (ObservationPtr());
-    } else {
-        return (obs->second);
-    }
+    ObservationPtr result;
+    auto lambda = [&]() {
+        auto obs = stats_.find(name);
+        if (obs != stats_.end()) {
+            result = obs->second;
+        }
+    };
+    MultiThreadingMgr::call(mutex_, lambda);
+    return (result);
 }
 
 void StatContext::add(const ObservationPtr& obs) {
-    std::map<std::string, ObservationPtr>::iterator existing = stats_.find(obs->getName());
-    if (existing == stats_.end()) {
-        stats_.insert(make_pair(obs->getName() ,obs));
-    } else {
-        isc_throw(DuplicateStat, "Statistic named " << obs->getName()
-                  << " already exists.");
-    }
-
+    auto lambda = [&]() {
+        auto existing = stats_.find(obs->getName());
+        if (existing == stats_.end()) {
+            stats_.insert(make_pair(obs->getName() ,obs));
+        } else {
+            isc_throw(DuplicateStat, "Statistic named " << obs->getName()
+                      << " already exists.");
+        }
+    };
+    MultiThreadingMgr::call(mutex_, lambda);
 }
 
 bool StatContext::del(const std::string& name) {
-    std::map<std::string, ObservationPtr>::iterator obs = stats_.find(name);
-    if (obs == stats_.end()) {
-        return (false);
-    } else {
-        stats_.erase(obs);
-        return (true);
-    }
+    bool result = false;
+    auto lambda = [&]() {
+        auto obs = stats_.find(name);
+        if (obs != stats_.end()) {
+            stats_.erase(obs);
+            result = true;
+        }
+    };
+    MultiThreadingMgr::call(mutex_, lambda);
+    return (result);
+}
+
+size_t StatContext::size() {
+    size_t size;
+    MultiThreadingMgr::call(mutex_, [&]() {size = stats_.size();});
+    return (size);
+}
+
+void StatContext::clear() {
+    MultiThreadingMgr::call(mutex_, [&]() {stats_.clear();});
+}
+
+void StatContext::reset() {
+    auto lambda = [&]() {
+        // Let's iterate over all stored statistics...
+        for (auto s : stats_) {
+            // ... and reset each statistic.
+            s.second->reset();
+        }
+    };
+    MultiThreadingMgr::call(mutex_, lambda);
+}
+
+ConstElementPtr
+StatContext::getAll() const {
+    ElementPtr map = isc::data::Element::createMap(); // a map
+    auto lambda = [&]() {
+        // Let's iterate over all stored statistics...
+        for (auto s : stats_) {
+            // ... and add each of them to the map.
+            map->set(s.first, s.second->getJSON());
+        }
+    };
+    MultiThreadingMgr::call(mutex_, lambda);
+    return (map);
+}
+
+void
+StatContext::setMaxSampleAgeAll(const StatsDuration& duration) {
+    auto lambda = [&]() {
+        // Let's iterate over all stored statistics...
+        for (auto s : stats_) {
+            // ... and set duration limit for each statistic.
+            s.second->setMaxSampleAge(duration);
+        }
+    };
+    MultiThreadingMgr::call(mutex_, lambda);
+}
+
+void
+StatContext::setMaxSampleCountAll(uint32_t max_samples) {
+    auto lambda = [&]() {
+        // Let's iterate over all stored statistics...
+        for (auto s : stats_) {
+            // ... and set count limit for each statistic.
+            s.second->setMaxSampleCount(max_samples);
+        }
+    };
+    MultiThreadingMgr::call(mutex_, lambda);
 }
 
 };

src/lib/stats/context.h

@@ -9,6 +9,7 @@
 
 #include <stats/observation.h>
 #include <boost/shared_ptr.hpp>
+#include <mutex>
 #include <string>
 
 namespace isc {
@@ -28,7 +29,7 @@ public:
 /// all statistics related to a given subnet or all statistics related to a
 /// given network interface.
 struct StatContext {
- public:
+public:
 
     /// @brief attempts to get an observation
     /// @param name name of the statistic
@@ -45,14 +46,23 @@ struct StatContext {
     /// @return true if successful, false if no such statistic was found
     bool del(const std::string& name);
 
+    size_t size();
+
+    void clear();
+
+    void reset();
+
+    void setMaxSampleAgeAll(const StatsDuration& duration);
+
+    void setMaxSampleCountAll(uint32_t max_samples);
+
+    isc::data::ConstElementPtr getAll() const;
+
+private:
     /// @brief Statistics container
-    ///
-    /// It is public to allow various operations that require iterating over
-    /// all elements. In particular, two operations (setting all stats to 0;
-    /// reporting all stats) will take advantage of this. Alternatively, we
-    /// could make it protected and then return a pointer to it, but that
-    /// would defeat the purpose of the hermetization in the first place.
     std::map<std::string, ObservationPtr> stats_;
+
+    mutable std::mutex mutex_;
 };
 
 /// @brief Pointer to the statistics context

src/lib/stats/stats_mgr.cc

@@ -11,183 +11,220 @@
 #include <cc/data.h>
 #include <cc/command_interpreter.h>
 #include <util/boost_time_utils.h>
+#include <util/multi_threading_mgr.h>
 #include <boost/date_time/posix_time/posix_time.hpp>
 
 using namespace std;
 using namespace isc::data;
 using namespace isc::config;
+using namespace isc::util;
 
 namespace isc {
 namespace stats {
 
-StatsMgr& StatsMgr::instance() {
+StatsMgr&
+StatsMgr::instance() {
     static StatsMgr stats_mgr;
     return (stats_mgr);
 }
 
 StatsMgr::StatsMgr() :
     global_(new StatContext()) {
-
 }
 
-void StatsMgr::setValue(const std::string& name, const int64_t value) {
-    setValueInternal(name, value);
+void
+StatsMgr::setValue(const string& name, const int64_t value) {
+    MultiThreadingMgr::call(mutex_, [&]() {setValueInternal(name, value);});
 }
 
-void StatsMgr::setValue(const std::string& name, const double value) {
-    setValueInternal(name, value);
+void
+StatsMgr::setValue(const string& name, const double value) {
+    MultiThreadingMgr::call(mutex_, [&]() {setValueInternal(name, value);});
 }
 
-void StatsMgr::setValue(const std::string& name, const StatsDuration& value) {
-    setValueInternal(name, value);
-}
-void StatsMgr::setValue(const std::string& name, const std::string& value) {
-    setValueInternal(name, value);
+void
+StatsMgr::setValue(const string& name, const StatsDuration& value) {
+    MultiThreadingMgr::call(mutex_, [&]() {setValueInternal(name, value);});
 }
 
-void StatsMgr::addValue(const std::string& name, const int64_t value) {
-    addValueInternal(name, value);
+void
+StatsMgr::setValue(const string& name, const string& value) {
+    MultiThreadingMgr::call(mutex_, [&]() {setValueInternal(name, value);});
 }
 
-void StatsMgr::addValue(const std::string& name, const double value) {
-    addValueInternal(name, value);
+void
+StatsMgr::addValue(const string& name, const int64_t value) {
+    MultiThreadingMgr::call(mutex_, [&]() {addValueInternal(name, value);});
 }
 
-void StatsMgr::addValue(const std::string& name, const StatsDuration& value) {
-    addValueInternal(name, value);
+void
+StatsMgr::addValue(const string& name, const double value) {
+    MultiThreadingMgr::call(mutex_, [&]() {addValueInternal(name, value);});
 }
 
-void StatsMgr::addValue(const std::string& name, const std::string& value) {
-    addValueInternal(name, value);
+void
+StatsMgr::addValue(const string& name, const StatsDuration& value) {
+    MultiThreadingMgr::call(mutex_, [&]() {addValueInternal(name, value);});
 }
 
-ObservationPtr StatsMgr::getObservation(const std::string& name) const {
+void
+StatsMgr::addValue(const string& name, const string& value) {
+    MultiThreadingMgr::call(mutex_, [&]() {addValueInternal(name, value);});
+}
+
+ObservationPtr
+StatsMgr::getObservation(const string& name) const {
+    ObservationPtr result;
+    MultiThreadingMgr::call(mutex_, [&]() {result = getObservationInternal(name);});
+    return (result);
+}
+
+ObservationPtr
+StatsMgr::getObservationInternal(const string& name) const {
     /// @todo: Implement contexts.
     // Currently we keep everything in a global context.
     return (global_->get(name));
 }
 
-void StatsMgr::addObservation(const ObservationPtr& stat) {
+void
+StatsMgr::addObservation(const ObservationPtr& stat) {
+    MultiThreadingMgr::call(mutex_, [&]() {addObservationInternal(stat);});
+}
+
+void
+StatsMgr::addObservationInternal(const ObservationPtr& stat) {
     /// @todo: Implement contexts.
     // Currently we keep everything in a global context.
     return (global_->add(stat));
 }
 
-bool StatsMgr::deleteObservation(const std::string& name) {
+bool
+StatsMgr::deleteObservation(const string& name) {
+    bool result;
+    MultiThreadingMgr::call(mutex_, [&]() {result = deleteObservationInternal(name);});
+    return (result);
+}
+
+bool
+StatsMgr::deleteObservationInternal(const string& name) {
     /// @todo: Implement contexts.
     // Currently we keep everything in a global context.
     return (global_->del(name));
 }
 
-bool StatsMgr::setMaxSampleAge(const std::string& name,
-                               const StatsDuration& duration) {
-    ObservationPtr obs = getObservation(name);
-    if (obs) {
-        obs->setMaxSampleAge(duration);
-        return (true);
-    } else {
-        return (false);
-    }
+bool
+StatsMgr::setMaxSampleAge(const string& name, const StatsDuration& duration) {
+    bool result = false;
+    auto lambda = [&]() {
+        ObservationPtr obs = getObservationInternal(name);
+        if (obs) {
+            obs->setMaxSampleAge(duration);
+            result = true;
+        }
+    };
+    MultiThreadingMgr::call(mutex_, lambda);
+    return (result);
 }
 
-bool StatsMgr::setMaxSampleCount(const std::string& name,
-                                 uint32_t max_samples) {
-    ObservationPtr obs = getObservation(name);
-    if (obs) {
-        obs->setMaxSampleCount(max_samples);
-        return (true);
-    } else {
-        return (false);
-    }
+bool
+StatsMgr::setMaxSampleCount(const string& name, uint32_t max_samples) {
+    bool result = false;
+    auto lambda = [&]() {
+        ObservationPtr obs = getObservationInternal(name);
+        if (obs) {
+            obs->setMaxSampleCount(max_samples);
+            result = true;
+        }
+    };
+    MultiThreadingMgr::call(mutex_, lambda);
+    return (result);
 }
 
-void StatsMgr::setMaxSampleAgeAll(const StatsDuration& duration) {
-    // Let's iterate over all stored statistics...
-    for (std::map<std::string, ObservationPtr>::iterator s = global_->stats_.begin();
-         s != global_->stats_.end(); ++s) {
-
-        // ... and set duration limit for each statistic.
-        s->second->setMaxSampleAge(duration);
-    }
+void
+StatsMgr::setMaxSampleAgeAll(const StatsDuration& duration) {
+    MultiThreadingMgr::call(mutex_, [&]() {global_->setMaxSampleAgeAll(duration);});
 }
 
-void StatsMgr::setMaxSampleCountAll(uint32_t max_samples) {
-    // Let's iterate over all stored statistics...
-    for (std::map<std::string, ObservationPtr>::iterator s = global_->stats_.begin();
-         s != global_->stats_.end(); ++s) {
-
-        // ... and set count limit for each statistic.
-        s->second->setMaxSampleCount(max_samples);
-    }
+void
+StatsMgr::setMaxSampleCountAll(uint32_t max_samples) {
+    MultiThreadingMgr::call(mutex_, [&]() {global_->setMaxSampleCountAll(max_samples);});
 }
 
-bool StatsMgr::reset(const std::string& name) {
-    ObservationPtr obs = getObservation(name);
-    if (obs) {
-        obs->reset();
-        return (true);
-    } else {
-        return (false);
-    }
+bool
+StatsMgr::reset(const string& name) {
+    bool result = false;
+    auto lambda = [&]() {
+        ObservationPtr obs = getObservationInternal(name);
+        if (obs) {
+            obs->reset();
+            result = true;
+        }
+    };
+    MultiThreadingMgr::call(mutex_, lambda);
+    return (result);
 }
 
-bool StatsMgr::del(const std::string& name) {
-    return (global_->del(name));
+bool
+StatsMgr::del(const string& name) {
+    bool result;
+    MultiThreadingMgr::call(mutex_, [&]() {result = global_->del(name);});
+    return (result);
 }
 
-void StatsMgr::removeAll() {
-    global_->stats_.clear();
+void
+StatsMgr::removeAll() {
+    MultiThreadingMgr::call(mutex_, [&]() {global_->clear();});
 }
 
-isc::data::ConstElementPtr StatsMgr::get(const std::string& name) const {
+ConstElementPtr
+StatsMgr::get(const string& name) const {
     isc::data::ElementPtr response = isc::data::Element::createMap(); // a map
-    ObservationPtr obs = getObservation(name);
-    if (obs) {
-        response->set(name, obs->getJSON()); // that contains observations
-    }
+    auto lambda = [&]() {
+        ObservationPtr obs = getObservationInternal(name);
+        if (obs) {
+            response->set(name, obs->getJSON()); // that contains observations
+        }
+    };
+    MultiThreadingMgr::call(mutex_, lambda);
     return (response);
 }
 
-isc::data::ConstElementPtr StatsMgr::getAll() const {
-    isc::data::ElementPtr map = isc::data::Element::createMap(); // a map
-
-    // Let's iterate over all stored statistics...
-    for (std::map<std::string, ObservationPtr>::iterator s = global_->stats_.begin();
-         s != global_->stats_.end(); ++s) {
-
-        // ... and add each of them to the map.
-        map->set(s->first, s->second->getJSON());
-    }
-    return (map);
+ConstElementPtr
+StatsMgr::getAll() const {
+    ConstElementPtr result;
+    MultiThreadingMgr::call(mutex_, [&]() {result = global_->getAll();});
+    return (result);
 }
 
-void StatsMgr::resetAll() {
-    // Let's iterate over all stored statistics...
-    for (std::map<std::string, ObservationPtr>::iterator s = global_->stats_.begin();
-         s != global_->stats_.end(); ++s) {
-
-        // ... and reset each statistic.
-        s->second->reset();
-    }
+void
+StatsMgr::resetAll() {
+    MultiThreadingMgr::call(mutex_, [&]() {global_->reset();});
 }
 
-size_t StatsMgr::getSize(const std::string& name) const {
-    ObservationPtr obs = getObservation(name);
+size_t
+StatsMgr::getSize(const string& name) const {
     size_t size = 0;
-    if (obs) {
-        size = obs->getSize();
-    }
+    auto lambda = [&]() {
+        ObservationPtr obs = getObservationInternal(name);
+        if (obs) {
+            size = obs->getSize();
+        }
+    };
+    MultiThreadingMgr::call(mutex_, lambda);
     return (size);
 }
 
-size_t StatsMgr::count() const {
-    return (global_->stats_.size());
+size_t
+StatsMgr::count() const {
+    size_t result;
+    MultiThreadingMgr::call(mutex_, [&]() {result = global_->size();});
+    return (result);
 }
 
-isc::data::ConstElementPtr
-StatsMgr::statisticSetMaxSampleAgeHandler(const std::string& /*name*/,
-                                          const isc::data::ConstElementPtr& params) {
-    std::string name, error;
+ConstElementPtr
+StatsMgr::statisticSetMaxSampleAgeHandler(const string& /*name*/,
+                                          const ConstElementPtr& params) {
+    string name, error;
     StatsDuration duration;
     if (!StatsMgr::getStatName(params, name, error)) {
         return (createAnswer(CONTROL_RESULT_ERROR, error));
@@ -204,10 +241,10 @@ StatsMgr::statisticSetMaxSampleAgeHandler(const std::string& /*name*/,
     }
 }
 
-isc::data::ConstElementPtr
-StatsMgr::statisticSetMaxSampleCountHandler(const std::string& /*name*/,
-                                            const isc::data::ConstElementPtr& params) {
-    std::string name, error;
+ConstElementPtr
+StatsMgr::statisticSetMaxSampleCountHandler(const string& /*name*/,
+                                            const ConstElementPtr& params) {
+    string name, error;
     uint32_t max_samples;
     if (!StatsMgr::getStatName(params, name, error)) {
         return (createAnswer(CONTROL_RESULT_ERROR, error));
@@ -224,10 +261,10 @@ StatsMgr::statisticSetMaxSampleCountHandler(const std::string& /*name*/,
     }
 }
 
-isc::data::ConstElementPtr
-StatsMgr::statisticGetHandler(const std::string& /*name*/,
-                              const isc::data::ConstElementPtr& params) {
-    std::string name, error;
+ConstElementPtr
+StatsMgr::statisticGetHandler(const string& /*name*/,
+                              const ConstElementPtr& params) {
+    string name, error;
     if (!StatsMgr::getStatName(params, name, error)) {
         return (createAnswer(CONTROL_RESULT_ERROR, error));
     }
@@ -235,14 +272,13 @@ StatsMgr::statisticGetHandler(const std::string& /*name*/,
                          StatsMgr::instance().get(name)));
 }
 
-isc::data::ConstElementPtr
-StatsMgr::statisticResetHandler(const std::string& /*name*/,
-                                const isc::data::ConstElementPtr& params) {
-    std::string name, error;
+ConstElementPtr
+StatsMgr::statisticResetHandler(const string& /*name*/,
+                                const ConstElementPtr& params) {
+    string name, error;
     if (!StatsMgr::getStatName(params, name, error)) {
         return (createAnswer(CONTROL_RESULT_ERROR, error));
     }
-
     if (StatsMgr::instance().reset(name)) {
         return (createAnswer(CONTROL_RESULT_SUCCESS,
                              "Statistic '" + name + "' reset."));
@@ -252,10 +288,10 @@ StatsMgr::statisticResetHandler(const std::string& /*name*/,
     }
 }
 
-isc::data::ConstElementPtr
-StatsMgr::statisticRemoveHandler(const std::string& /*name*/,
-                                 const isc::data::ConstElementPtr& params) {
-    std::string name, error;
+ConstElementPtr
+StatsMgr::statisticRemoveHandler(const string& /*name*/,
+                                 const ConstElementPtr& params) {
+    string name, error;
     if (!StatsMgr::getStatName(params, name, error)) {
         return (createAnswer(CONTROL_RESULT_ERROR, error));
     }
@@ -269,33 +305,33 @@ StatsMgr::statisticRemoveHandler(const std::string& /*name*/,
 
 }
 
-isc::data::ConstElementPtr
-StatsMgr::statisticRemoveAllHandler(const std::string& /*name*/,
-                                    const isc::data::ConstElementPtr& /*params*/) {
+ConstElementPtr
+StatsMgr::statisticRemoveAllHandler(const string& /*name*/,
+                                    const ConstElementPtr& /*params*/) {
     StatsMgr::instance().removeAll();
     return (createAnswer(CONTROL_RESULT_SUCCESS,
                          "All statistics removed."));
 }
 
-isc::data::ConstElementPtr
-StatsMgr::statisticGetAllHandler(const std::string& /*name*/,
-                                 const isc::data::ConstElementPtr& /*params*/) {
+ConstElementPtr
+StatsMgr::statisticGetAllHandler(const string& /*name*/,
+                                 const ConstElementPtr& /*params*/) {
     ConstElementPtr all_stats = StatsMgr::instance().getAll();
     return (createAnswer(CONTROL_RESULT_SUCCESS, all_stats));
 }
 
-isc::data::ConstElementPtr
-StatsMgr::statisticResetAllHandler(const std::string& /*name*/,
-                                   const isc::data::ConstElementPtr& /*params*/) {
+ConstElementPtr
+StatsMgr::statisticResetAllHandler(const string& /*name*/,
+                                   const ConstElementPtr& /*params*/) {
     StatsMgr::instance().resetAll();
     return (createAnswer(CONTROL_RESULT_SUCCESS,
                          "All statistics reset to neutral values."));
 }
 
-isc::data::ConstElementPtr
-StatsMgr::statisticSetMaxSampleAgeAllHandler(const std::string& /*name*/,
-                                             const isc::data::ConstElementPtr& params) {
-    std::string error;
+ConstElementPtr
+StatsMgr::statisticSetMaxSampleAgeAllHandler(const string& /*name*/,
+                                             const ConstElementPtr& params) {
+    string error;
     StatsDuration duration;
     if (!StatsMgr::getStatDuration(params, duration, error)) {
         return (createAnswer(CONTROL_RESULT_ERROR, error));
@@ -305,10 +341,10 @@ StatsMgr::statisticSetMaxSampleAgeAllHandler(const std::string& /*name*/,
                          "All statistics duration limit are set."));
 }
 
-isc::data::ConstElementPtr
-StatsMgr::statisticSetMaxSampleCountAllHandler(const std::string& /*name*/,
-                                               const isc::data::ConstElementPtr& params) {
-    std::string error;
+ConstElementPtr
+StatsMgr::statisticSetMaxSampleCountAllHandler(const string& /*name*/,
+                                               const ConstElementPtr& params) {
+    string error;
     uint32_t max_samples;
     if (!StatsMgr::getStatMaxSamples(params, max_samples, error)) {
         return (createAnswer(CONTROL_RESULT_ERROR, error));
@@ -319,9 +355,9 @@ StatsMgr::statisticSetMaxSampleCountAllHandler(const std::string& /*name*/,
 }
 
 bool
-StatsMgr::getStatName(const isc::data::ConstElementPtr& params,
-                      std::string& name,
-                      std::string& reason) {
+StatsMgr::getStatName(const ConstElementPtr& params,
+                      string& name,
+                      string& reason) {
     if (!params) {
         reason = "Missing mandatory 'name' parameter.";
         return (false);
@@ -335,15 +371,14 @@ StatsMgr::getStatName(const isc::data::ConstElementPtr& params,
         reason = "'name' parameter expected to be a string.";
         return (false);
     }
-
     name = stat_name->stringValue();
     return (true);
 }
 
 bool
-StatsMgr::getStatDuration(const isc::data::ConstElementPtr& params,
+StatsMgr::getStatDuration(const ConstElementPtr& params,
                           StatsDuration& duration,
-                          std::string& reason) {
+                          string& reason) {
     if (!params) {
         reason = "Missing mandatory 'duration' parameter.";
         return (false);
@@ -353,24 +388,20 @@ StatsMgr::getStatDuration(const isc::data::ConstElementPtr& params,
         reason = "Missing mandatory 'duration' parameter.";
         return (false);
     }
-
     int64_t time_duration = stat_duration->intValue();
-
     int64_t hours = time_duration / 3600;
     time_duration -= hours * 3600;
-
     int64_t minutes = time_duration / 60;
     time_duration -= minutes * 60;
-
     int64_t seconds = time_duration;
     duration = boost::posix_time::time_duration(hours, minutes, seconds, 0);
     return (true);
 }
 
 bool
-StatsMgr::getStatMaxSamples(const isc::data::ConstElementPtr& params,
+StatsMgr::getStatMaxSamples(const ConstElementPtr& params,
                             uint32_t& max_samples,
-                            std::string& reason) {
+                            string& reason) {
     if (!params) {
         reason = "Missing mandatory 'max-samples' parameter.";
         return (false);
@@ -384,7 +415,6 @@ StatsMgr::getStatMaxSamples(const isc::data::ConstElementPtr& params,
         reason = "'max-samples' parameter expected to be an integer.";
         return (false);
     }
-
     max_samples = stat_max_samples->intValue();
     return (true);
 }

src/lib/stats/stats_mgr.h

@@ -12,6 +12,7 @@
 #include <boost/noncopyable.hpp>
 
 #include <map>
+#include <mutex>
 #include <string>
 #include <vector>
 #include <sstream>
@@ -224,6 +225,8 @@ class StatsMgr : public boost::noncopyable {
     /// @return Pointer to the Observation object
     ObservationPtr getObservation(const std::string& name) const;
 
+    ObservationPtr getObservationInternal(const std::string& name) const;
+
     /// @brief Generates statistic name in a given context
     ///
     /// Example:
@@ -447,14 +450,13 @@ private:
     /// @throw InvalidStatType is statistic exists and has a different type.
     template<typename DataType>
     void setValueInternal(const std::string& name, DataType value) {
-
         // If we want to log each observation, here would be the best place for it.
-        ObservationPtr stat = getObservation(name);
+        ObservationPtr stat = getObservationInternal(name);
         if (stat) {
             stat->setValue(value);
         } else {
             stat.reset(new Observation(name, value));
-            addObservation(stat);
+            addObservationInternal(stat);
         }
     }
 
@@ -472,14 +474,13 @@ private:
     /// @throw InvalidStatType is statistic exists and has a different type.
     template<typename DataType>
     void addValueInternal(const std::string& name, DataType value) {
-
         // If we want to log each observation, here would be the best place for it.
-        ObservationPtr existing = getObservation(name);
+        ObservationPtr existing = getObservationInternal(name);
         if (!existing) {
             // We tried to add to a non-existing statistic. We can recover from
             // that. Simply add the new incremental value as a new statistic and
             // we're done.
-            setValue(name, value);
+            setValueInternal(name, value);
             return;
         } else {
             // Let's hope it is of correct type. If not, the underlying
@@ -497,6 +498,8 @@ private:
     /// @param stat observation
     void addObservation(const ObservationPtr& stat);
 
+    void addObservationInternal(const ObservationPtr& stat);
+
     /// @private
 
     /// @brief Tries to delete an observation.
@@ -505,6 +508,8 @@ private:
     /// @return true if deleted, false if not found
     bool deleteObservation(const std::string& name);
 
+    bool deleteObservationInternal(const std::string& name);
+
     /// @brief Utility method that attempts to extract statistic name
     ///
     /// This method attempts to extract statistic name from the params
@@ -562,6 +567,9 @@ private:
 
     // This is a global context. All statistics will initially be stored here.
     StatContextPtr global_;
+
+    /// @brief Mutex for protecting stats.
+    mutable std::mutex mutex_;
 };
 
 };

src/lib/stats/tests/context_unittest.cc

@@ -24,8 +24,7 @@ TEST(ContextTest, basic) {
     StatContext ctx;
 
     // By default the context does not hold any statistics.
-    EXPECT_EQ(0, ctx.stats_.size());
-    EXPECT_TRUE(ctx.stats_.empty());
+    EXPECT_EQ(0, ctx.size());
 
     // It should be possible to add 'a' statistic
     EXPECT_NO_THROW(ctx.add(a));
@@ -38,8 +37,7 @@ TEST(ContextTest, basic) {
     EXPECT_NO_THROW(ctx.add(c));
 
     // By now we should have 3 statistics recorded
-    EXPECT_EQ(3, ctx.stats_.size());
-    EXPECT_FALSE(ctx.stats_.empty());
+    EXPECT_EQ(3, ctx.size());
 
     // Let's try to retrieve them
     ObservationPtr from_ctx;

src/lib/util/multi_threading_mgr.h

@@ -8,6 +8,7 @@
 #define MULTI_THREADING_MGR_H
 
 #include <boost/noncopyable.hpp>
+#include <mutex>
 
 namespace isc {
 namespace util {
@@ -62,6 +63,16 @@ public:
     /// @param enabled The new mode.
     void setMode(bool enabled);
 
+    template<typename Callable>
+    static void call(std::mutex& lk, const Callable& f) {
+        if (MultiThreadingMgr::instance().getMode()) {
+            std::lock_guard<std::mutex> lock(lk);
+            f();
+        } else {
+            f();
+        }
+    }
+
 protected:
 
     /// @brief Constructor.