Merge branch 'navmesh_job' into 'master'

Store async navmesh jobs in the same container until they are processed

See merge request OpenMW/openmw!1131

components/detournavigator/asyncnavmeshupdater.cpp

@@ -20,6 +20,8 @@ namespace
     using DetourNavigator::TilePosition;
     using DetourNavigator::UpdateType;
     using DetourNavigator::ChangeType;
+    using DetourNavigator::Job;
+    using DetourNavigator::JobIt;
 
     int getManhattanDistance(const TilePosition& lhs, const TilePosition& rhs)
     {
@@ -27,14 +29,13 @@ namespace
     }
 
     int getMinDistanceTo(const TilePosition& position, int maxDistance,
-                         const std::map<osg::Vec3f, std::set<TilePosition>>& tilesPerHalfExtents,
+                         const std::set<std::tuple<osg::Vec3f, TilePosition>>& pushedTiles,
                          const std::set<std::tuple<osg::Vec3f, TilePosition>>& presentTiles)
     {
         int result = maxDistance;
-        for (const auto& [halfExtents, tiles] : tilesPerHalfExtents)
-            for (const TilePosition& tile : tiles)
-                if (presentTiles.find(std::make_tuple(halfExtents, tile)) == presentTiles.end())
-                    result = std::min(result, getManhattanDistance(position, tile));
+        for (const auto& [halfExtents, tile] : pushedTiles)
+            if (presentTiles.find(std::tie(halfExtents, tile)) == presentTiles.end())
+                result = std::min(result, getManhattanDistance(position, tile));
         return result;
     }
 
@@ -44,34 +45,45 @@ namespace
             return UpdateType::Temporary;
         return UpdateType::Persistent;
     }
+
+    auto getPriority(const Job& job) noexcept
+    {
+        return std::make_tuple(job.mProcessTime, job.mTryNumber, job.mChangeType, job.mDistanceToPlayer, job.mDistanceToOrigin);
+    }
+
+    struct LessByJobPriority
+    {
+        bool operator()(JobIt lhs, JobIt rhs) const noexcept
+        {
+            return getPriority(*lhs) < getPriority(*rhs);
+        }
+    };
+
+    void insertPrioritizedJob(JobIt job, std::deque<JobIt>& queue)
+    {
+        const auto it = std::upper_bound(queue.begin(), queue.end(), job, LessByJobPriority {});
+        queue.insert(it, job);
+    }
+
+    auto getAgentAndTile(const Job& job) noexcept
+    {
+        return std::make_tuple(job.mAgentHalfExtents, job.mChangedTile);
+    }
 }
 
 namespace DetourNavigator
 {
-    static std::ostream& operator <<(std::ostream& stream, UpdateNavMeshStatus value)
+    Job::Job(const osg::Vec3f& agentHalfExtents, std::weak_ptr<GuardedNavMeshCacheItem> navMeshCacheItem,
+        const TilePosition& changedTile, ChangeType changeType, int distanceToPlayer,
+        std::chrono::steady_clock::time_point processTime)
+        : mAgentHalfExtents(agentHalfExtents)
+        , mNavMeshCacheItem(std::move(navMeshCacheItem))
+        , mChangedTile(changedTile)
+        , mProcessTime(processTime)
+        , mChangeType(changeType)
+        , mDistanceToPlayer(distanceToPlayer)
+        , mDistanceToOrigin(getManhattanDistance(changedTile, TilePosition {0, 0}))
     {
-        switch (value)
-        {
-            case UpdateNavMeshStatus::ignored:
-                return stream << "ignore";
-            case UpdateNavMeshStatus::removed:
-                return stream << "removed";
-            case UpdateNavMeshStatus::added:
-                return stream << "add";
-            case UpdateNavMeshStatus::replaced:
-                return stream << "replaced";
-            case UpdateNavMeshStatus::failed:
-                return stream << "failed";
-            case UpdateNavMeshStatus::lost:
-                return stream << "lost";
-            case UpdateNavMeshStatus::cached:
-                return stream << "cached";
-            case UpdateNavMeshStatus::unchanged:
-                return stream << "unchanged";
-            case UpdateNavMeshStatus::restored:
-                return stream << "restored";
-        }
-        return stream << "unknown(" << static_cast<unsigned>(value) << ")";
     }
 
     AsyncNavMeshUpdater::AsyncNavMeshUpdater(const Settings& settings, TileCachedRecastMeshManager& recastMeshManager,
@@ -90,7 +102,8 @@ namespace DetourNavigator
     {
         mShouldStop = true;
         std::unique_lock<std::mutex> lock(mMutex);
-        mJobs = decltype(mJobs)();
+        mThreadsQueues.clear();
+        mWaiting.clear();
         mHasJob.notify_all();
         lock.unlock();
         for (auto& thread : mThreads)
@@ -114,44 +127,33 @@ namespace DetourNavigator
         const std::lock_guard<std::mutex> lock(mMutex);
 
         if (playerTileChanged)
-            for (auto& job : mJobs)
-                job.mDistanceToPlayer = getManhattanDistance(job.mChangedTile, playerTile);
+            for (JobIt job : mWaiting)
+                job->mDistanceToPlayer = getManhattanDistance(job->mChangedTile, playerTile);
 
-        for (const auto& changedTile : changedTiles)
+        for (const auto& [changedTile, changeType] : changedTiles)
         {
-            if (mPushed[agentHalfExtents].insert(changedTile.first).second)
+            if (mPushed.emplace(agentHalfExtents, changedTile).second)
             {
-                Job job;
-
-                job.mAgentHalfExtents = agentHalfExtents;
-                job.mNavMeshCacheItem = navMeshCacheItem;
-                job.mChangedTile = changedTile.first;
-                job.mTryNumber = 0;
-                job.mChangeType = changedTile.second;
-                job.mDistanceToPlayer = getManhattanDistance(changedTile.first, playerTile);
-                job.mDistanceToOrigin = getManhattanDistance(changedTile.first, TilePosition {0, 0});
-                job.mProcessTime = job.mChangeType == ChangeType::update
-                    ? mLastUpdates[job.mAgentHalfExtents][job.mChangedTile] + mSettings.get().mMinUpdateInterval
+                const auto processTime = changeType == ChangeType::update
+                    ? mLastUpdates[std::tie(agentHalfExtents, changedTile)] + mSettings.get().mMinUpdateInterval
                     : std::chrono::steady_clock::time_point();
 
+                const JobIt it = mJobs.emplace(mJobs.end(), agentHalfExtents, navMeshCacheItem, changedTile,
+                    changeType, getManhattanDistance(changedTile, playerTile), processTime);
+
                 if (playerTileChanged)
-                {
-                    mJobs.push_back(std::move(job));
-                }
+                    mWaiting.push_back(it);
                 else
-                {
-                    const auto it = std::upper_bound(mJobs.begin(), mJobs.end(), job);
-                    mJobs.insert(it, std::move(job));
-                }
+                    insertPrioritizedJob(it, mWaiting);
             }
         }
 
         if (playerTileChanged)
-            std::sort(mJobs.begin(), mJobs.end());
+            std::sort(mWaiting.begin(), mWaiting.end(), LessByJobPriority {});
 
         Log(Debug::Debug) << "Posted " << mJobs.size() << " navigator jobs";
 
-        if (!mJobs.empty())
+        if (!mWaiting.empty())
             mHasJob.notify_all();
     }
 
@@ -192,15 +194,13 @@ namespace DetourNavigator
         int minDistanceToPlayer = 0;
         const auto isDone = [&]
         {
-            jobsLeft = mJobs.size() + getTotalThreadJobsUnsafe();
+            jobsLeft = mJobs.size();
             if (jobsLeft == 0)
             {
                 minDistanceToPlayer = 0;
                 return true;
             }
             minDistanceToPlayer = getMinDistanceTo(playerPosition, maxDistanceToPlayer, mPushed, mPresentTiles);
-            for (const auto& [threadId, queue] : mThreadsQueues)
-                minDistanceToPlayer = getMinDistanceTo(playerPosition, minDistanceToPlayer, queue.mPushed, mPresentTiles);
             return minDistanceToPlayer >= maxDistanceToPlayer;
         };
         std::unique_lock<std::mutex> lock(mMutex);
@@ -227,7 +227,7 @@ namespace DetourNavigator
     {
         {
             std::unique_lock<std::mutex> lock(mMutex);
-            mDone.wait(lock, [this] { return mJobs.size() + getTotalThreadJobsUnsafe() == 0; });
+            mDone.wait(lock, [this] { return mJobs.size() == 0; });
         }
         mProcessingTiles.wait(mProcessed, [] (const auto& v) { return v.empty(); });
     }
@@ -238,7 +238,7 @@ namespace DetourNavigator
 
         {
             const std::lock_guard<std::mutex> lock(mMutex);
-            jobs = mJobs.size() + getTotalThreadJobsUnsafe();
+            jobs = mJobs.size();
         }
 
         stats.setAttribute(frameNumber, "NavMesh UpdateJobs", jobs);
@@ -254,12 +254,14 @@ namespace DetourNavigator
         {
             try
             {
-                if (auto job = getNextJob())
+                if (JobIt job = getNextJob(); job != mJobs.end())
                 {
                     const auto processed = processJob(*job);
                     unlockTile(job->mAgentHalfExtents, job->mChangedTile);
-                    if (!processed)
-                        repost(std::move(*job));
+                    if (processed)
+                        removeJob(job);
+                    else
+                        repost(job);
                 }
                 else
                     cleanupLastUpdates();
@@ -279,8 +281,6 @@ namespace DetourNavigator
 
         const auto start = std::chrono::steady_clock::now();
 
-        const auto firstStart = setFirstStart(start);
-
         const auto navMeshCacheItem = job.mNavMeshCacheItem.lock();
 
         if (!navMeshCacheItem)
@@ -331,13 +331,12 @@ namespace DetourNavigator
             " generation=" << locked->getGeneration() <<
             " revision=" << locked->getNavMeshRevision() <<
             " time=" << std::chrono::duration_cast<FloatMs>(finish - start).count() << "ms" <<
-            " total_time=" << std::chrono::duration_cast<FloatMs>(finish - firstStart).count() << "ms"
             " thread=" << std::this_thread::get_id();
 
         return isSuccess(status);
     }
 
-    std::optional<AsyncNavMeshUpdater::Job> AsyncNavMeshUpdater::getNextJob()
+    JobIt AsyncNavMeshUpdater::getNextJob()
     {
         std::unique_lock<std::mutex> lock(mMutex);
 
@@ -347,54 +346,51 @@ namespace DetourNavigator
         while (true)
         {
             const auto hasJob = [&] {
-                return (!mJobs.empty() && mJobs.front().mProcessTime <= std::chrono::steady_clock::now())
-                    || !threadQueue.mJobs.empty();
+                return (!mWaiting.empty() && mWaiting.front()->mProcessTime <= std::chrono::steady_clock::now())
+                    || !threadQueue.empty();
             };
 
             if (!mHasJob.wait_for(lock, std::chrono::milliseconds(10), hasJob))
             {
-                mFirstStart.lock()->reset();
-                if (mJobs.empty() && getTotalThreadJobsUnsafe() == 0)
+                if (mJobs.empty())
                     mDone.notify_all();
-                return std::nullopt;
+                return mJobs.end();
             }
 
             Log(Debug::Debug) << "Got " << mJobs.size() << " navigator jobs and "
-                << threadQueue.mJobs.size() << " thread jobs by thread=" << std::this_thread::get_id();
+                << threadQueue.size() << " thread jobs by thread=" << std::this_thread::get_id();
 
-            auto job = threadQueue.mJobs.empty()
-                ? getJob(mJobs, mPushed, true)
-                : getJob(threadQueue.mJobs, threadQueue.mPushed, false);
+            const JobIt job = threadQueue.empty()
+                ? getJob(mWaiting, true)
+                : getJob(threadQueue, false);
 
-            if (!job)
+            if (job == mJobs.end())
                 continue;
 
             const auto owner = lockTile(job->mAgentHalfExtents, job->mChangedTile);
 
             if (owner == threadId)
+            {
+                mPushed.erase(getAgentAndTile(*job));
                 return job;
+            }
 
-            postThreadJob(std::move(*job), mThreadsQueues[owner]);
+            postThreadJob(job, mThreadsQueues[owner]);
         }
     }
 
-    std::optional<AsyncNavMeshUpdater::Job> AsyncNavMeshUpdater::getJob(Jobs& jobs, Pushed& pushed, bool changeLastUpdate)
+    JobIt AsyncNavMeshUpdater::getJob(std::deque<JobIt>& jobs, bool changeLastUpdate)
     {
         const auto now = std::chrono::steady_clock::now();
+        JobIt job = jobs.front();
 
-        if (jobs.front().mProcessTime > now)
-            return {};
+        if (job->mProcessTime > now)
+            return mJobs.end();
 
-        Job job = jobs.front();
         jobs.pop_front();
 
-        if (changeLastUpdate && job.mChangeType == ChangeType::update)
-            mLastUpdates[job.mAgentHalfExtents][job.mChangedTile] = now;
-
-        const auto it = pushed.find(job.mAgentHalfExtents);
-        it->second.erase(job.mChangedTile);
-        if (it->second.empty())
-            pushed.erase(it);
+        if (changeLastUpdate && job->mChangeType == ChangeType::update)
+            mLastUpdates[getAgentAndTile(*job)] = now;
 
         return job;
     }
@@ -422,36 +418,28 @@ namespace DetourNavigator
                 writeToFile(shared->lockConst()->getImpl(), mSettings.get().mNavMeshPathPrefix, navMeshRevision);
     }
 
-    std::chrono::steady_clock::time_point AsyncNavMeshUpdater::setFirstStart(const std::chrono::steady_clock::time_point& value)
+    void AsyncNavMeshUpdater::repost(JobIt job)
     {
-        const auto locked = mFirstStart.lock();
-        if (!*locked)
-            *locked = value;
-        return *locked.get();
-    }
-
-    void AsyncNavMeshUpdater::repost(Job&& job)
-    {
-        if (mShouldStop || job.mTryNumber > 2)
+        if (mShouldStop || job->mTryNumber > 2)
             return;
 
         const std::lock_guard<std::mutex> lock(mMutex);
 
-        if (mPushed[job.mAgentHalfExtents].insert(job.mChangedTile).second)
+        if (mPushed.emplace(job->mAgentHalfExtents, job->mChangedTile).second)
         {
-            ++job.mTryNumber;
-            mJobs.push_back(std::move(job));
+            ++job->mTryNumber;
+            mWaiting.push_back(job);
             mHasJob.notify_all();
+            return;
         }
+
+        mJobs.erase(job);
     }
 
-    void AsyncNavMeshUpdater::postThreadJob(Job&& job, Queue& queue)
+    void AsyncNavMeshUpdater::postThreadJob(JobIt job, std::deque<JobIt>& queue)
     {
-        if (queue.mPushed[job.mAgentHalfExtents].insert(job.mChangedTile).second)
-        {
-            queue.mJobs.push_back(std::move(job));
-            mHasJob.notify_all();
-        }
+        queue.push_back(job);
+        mHasJob.notify_all();
     }
 
     std::thread::id AsyncNavMeshUpdater::lockTile(const osg::Vec3f& agentHalfExtents, const TilePosition& changedTile)
@@ -460,23 +448,13 @@ namespace DetourNavigator
             return std::this_thread::get_id();
 
         auto locked = mProcessingTiles.lock();
-
-        auto agent = locked->find(agentHalfExtents);
-        if (agent == locked->end())
+        const auto tile = locked->find(std::make_tuple(agentHalfExtents, changedTile));
+        if (tile == locked->end())
         {
             const auto threadId = std::this_thread::get_id();
-            locked->emplace(agentHalfExtents, std::map<TilePosition, std::thread::id>({{changedTile, threadId}}));
+            locked->emplace(std::tie(agentHalfExtents, changedTile), threadId);
             return threadId;
         }
-
-        auto tile = agent->second.find(changedTile);
-        if (tile == agent->second.end())
-        {
-            const auto threadId = std::this_thread::get_id();
-            agent->second.emplace(changedTile, threadId);
-            return threadId;
-        }
-
         return tile->second;
     }
 
@@ -484,22 +462,8 @@ namespace DetourNavigator
     {
         if (mSettings.get().mAsyncNavMeshUpdaterThreads <= 1)
             return;
-
         auto locked = mProcessingTiles.lock();
-
-        auto agent = locked->find(agentHalfExtents);
-        if (agent == locked->end())
-            return;
-
-        auto tile = agent->second.find(changedTile);
-        if (tile == agent->second.end())
-            return;
-
-        agent->second.erase(tile);
-
-        if (agent->second.empty())
-            locked->erase(agent);
-
+        locked->erase(std::tie(agentHalfExtents, changedTile));
         if (locked->empty())
             mProcessed.notify_all();
     }
@@ -507,13 +471,7 @@ namespace DetourNavigator
     std::size_t AsyncNavMeshUpdater::getTotalJobs() const
     {
         const std::scoped_lock lock(mMutex);
-        return mJobs.size() + getTotalThreadJobsUnsafe();
-    }
-
-    std::size_t AsyncNavMeshUpdater::getTotalThreadJobsUnsafe() const
-    {
-        return std::accumulate(mThreadsQueues.begin(), mThreadsQueues.end(), std::size_t(0),
-            [] (auto r, const auto& v) { return r + v.second.mJobs.size(); });
+        return mJobs.size();
     }
 
     void AsyncNavMeshUpdater::cleanupLastUpdates()
@@ -522,20 +480,18 @@ namespace DetourNavigator
 
         const std::lock_guard<std::mutex> lock(mMutex);
 
-        for (auto agent = mLastUpdates.begin(); agent != mLastUpdates.end();)
+        for (auto it = mLastUpdates.begin(); it != mLastUpdates.end();)
         {
-            for (auto tile = agent->second.begin(); tile != agent->second.end();)
-            {
-                if (now - tile->second > mSettings.get().mMinUpdateInterval)
-                    tile = agent->second.erase(tile);
-                else
-                    ++tile;
-            }
-
-            if (agent->second.empty())
-                agent = mLastUpdates.erase(agent);
+            if (now - it->second > mSettings.get().mMinUpdateInterval)
+                it = mLastUpdates.erase(it);
             else
-                ++agent;
+                ++it;
         }
     }
+
+    void AsyncNavMeshUpdater::removeJob(JobIt job)
+    {
+        const std::lock_guard lock(mMutex);
+        mJobs.erase(job);
+    }
 }

components/detournavigator/asyncnavmeshupdater.hpp

@@ -19,6 +19,7 @@
 #include <set>
 #include <thread>
 #include <tuple>
+#include <list>
 
 class dtNavMesh;
 
@@ -52,6 +53,24 @@ namespace DetourNavigator
         return stream << "ChangeType::" << static_cast<int>(value);
     }
 
+    struct Job
+    {
+        const osg::Vec3f mAgentHalfExtents;
+        const std::weak_ptr<GuardedNavMeshCacheItem> mNavMeshCacheItem;
+        const TilePosition mChangedTile;
+        const std::chrono::steady_clock::time_point mProcessTime;
+        unsigned mTryNumber = 0;
+        const ChangeType mChangeType;
+        int mDistanceToPlayer;
+        const int mDistanceToOrigin;
+
+        Job(const osg::Vec3f& agentHalfExtents, std::weak_ptr<GuardedNavMeshCacheItem> navMeshCacheItem,
+            const TilePosition& changedTile, ChangeType changeType, int distanceToPlayer,
+            std::chrono::steady_clock::time_point processTime);
+    };
+
+    using JobIt = std::list<Job>::iterator;
+
     class AsyncNavMeshUpdater
     {
     public:
@@ -67,39 +86,6 @@ namespace DetourNavigator
         void reportStats(unsigned int frameNumber, osg::Stats& stats) const;
 
     private:
-        struct Job
-        {
-            osg::Vec3f mAgentHalfExtents;
-            std::weak_ptr<GuardedNavMeshCacheItem> mNavMeshCacheItem;
-            TilePosition mChangedTile;
-            unsigned mTryNumber;
-            ChangeType mChangeType;
-            int mDistanceToPlayer;
-            int mDistanceToOrigin;
-            std::chrono::steady_clock::time_point mProcessTime;
-
-            std::tuple<std::chrono::steady_clock::time_point, unsigned, ChangeType, int, int> getPriority() const
-            {
-                return std::make_tuple(mProcessTime, mTryNumber, mChangeType, mDistanceToPlayer, mDistanceToOrigin);
-            }
-
-            friend inline bool operator <(const Job& lhs, const Job& rhs)
-            {
-                return lhs.getPriority() < rhs.getPriority();
-            }
-        };
-
-        using Jobs = std::deque<Job>;
-        using Pushed = std::map<osg::Vec3f, std::set<TilePosition>>;
-
-        struct Queue
-        {
-            Jobs mJobs;
-            Pushed mPushed;
-
-            Queue() = default;
-        };
-
         std::reference_wrapper<const Settings> mSettings;
         std::reference_wrapper<TileCachedRecastMeshManager> mRecastMeshManager;
         std::reference_wrapper<OffMeshConnectionsManager> mOffMeshConnectionsManager;
@@ -108,32 +94,30 @@ namespace DetourNavigator
         std::condition_variable mHasJob;
         std::condition_variable mDone;
         std::condition_variable mProcessed;
-        Jobs mJobs;
-        std::map<osg::Vec3f, std::set<TilePosition>> mPushed;
+        std::list<Job> mJobs;
+        std::deque<JobIt> mWaiting;
+        std::set<std::tuple<osg::Vec3f, TilePosition>> mPushed;
         Misc::ScopeGuarded<TilePosition> mPlayerTile;
-        Misc::ScopeGuarded<std::optional<std::chrono::steady_clock::time_point>> mFirstStart;
         NavMeshTilesCache mNavMeshTilesCache;
-        Misc::ScopeGuarded<std::map<osg::Vec3f, std::map<TilePosition, std::thread::id>>> mProcessingTiles;
-        std::map<osg::Vec3f, std::map<TilePosition, std::chrono::steady_clock::time_point>> mLastUpdates;
+        Misc::ScopeGuarded<std::map<std::tuple<osg::Vec3f, TilePosition>, std::thread::id>> mProcessingTiles;
+        std::map<std::tuple<osg::Vec3f, TilePosition>, std::chrono::steady_clock::time_point> mLastUpdates;
         std::set<std::tuple<osg::Vec3f, TilePosition>> mPresentTiles;
-        std::map<std::thread::id, Queue> mThreadsQueues;
+        std::map<std::thread::id, std::deque<JobIt>> mThreadsQueues;
         std::vector<std::thread> mThreads;
 
         void process() noexcept;
 
         bool processJob(const Job& job);
 
-        std::optional<Job> getNextJob();
+        JobIt getNextJob();
 
-        std::optional<Job> getJob(Jobs& jobs, Pushed& pushed, bool changeLastUpdate);
+        JobIt getJob(std::deque<JobIt>& jobs, bool changeLastUpdate);
 
-        void postThreadJob(Job&& job, Queue& queue);
+        void postThreadJob(JobIt job, std::deque<JobIt>& queue);
 
         void writeDebugFiles(const Job& job, const RecastMesh* recastMesh) const;
 
-        std::chrono::steady_clock::time_point setFirstStart(const std::chrono::steady_clock::time_point& value);
-
-        void repost(Job&& job);
+        void repost(JobIt job);
 
         std::thread::id lockTile(const osg::Vec3f& agentHalfExtents, const TilePosition& changedTile);
 
@@ -141,13 +125,13 @@ namespace DetourNavigator
 
         inline std::size_t getTotalJobs() const;
 
-        inline std::size_t getTotalThreadJobsUnsafe() const;
-
         void cleanupLastUpdates();
 
         int waitUntilJobsDoneForNotPresentTiles(const std::size_t initialJobsLeft, std::size_t& maxJobsLeft, Loading::Listener& listener);
 
         void waitUntilAllJobsDone();
+
+        inline void removeJob(JobIt job);
     };
 }
 

components/detournavigator/navmeshcacheitem.hpp

@@ -10,6 +10,7 @@
 #include <components/misc/guarded.hpp>
 
 #include <map>
+#include <ostream>
 
 struct dtMeshTile;
 
@@ -33,6 +34,32 @@ namespace DetourNavigator
         return (static_cast<unsigned>(value) & static_cast<unsigned>(UpdateNavMeshStatus::failed)) == 0;
     }
 
+    inline std::ostream& operator <<(std::ostream& stream, UpdateNavMeshStatus value)
+    {
+        switch (value)
+        {
+            case UpdateNavMeshStatus::ignored:
+                return stream << "ignore";
+            case UpdateNavMeshStatus::removed:
+                return stream << "removed";
+            case UpdateNavMeshStatus::added:
+                return stream << "add";
+            case UpdateNavMeshStatus::replaced:
+                return stream << "replaced";
+            case UpdateNavMeshStatus::failed:
+                return stream << "failed";
+            case UpdateNavMeshStatus::lost:
+                return stream << "lost";
+            case UpdateNavMeshStatus::cached:
+                return stream << "cached";
+            case UpdateNavMeshStatus::unchanged:
+                return stream << "unchanged";
+            case UpdateNavMeshStatus::restored:
+                return stream << "restored";
+        }
+        return stream << "unknown(" << static_cast<unsigned>(value) << ")";
+    }
+
     class UpdateNavMeshStatusBuilder
     {
     public: