Lua: Add MP.CreateTimedEvent as CreateThread replacement

Changelog.md

@@ -21,6 +21,7 @@
 - ADDED `MP.HttpsPOST(host,port,target,body,content_type) -> status,body`: Does a synchronous HTTPS POST request
 - ADDED `MP.GetStateMemoryUsage() -> number`: Current memory usage of the current state in bytes
 - ADDED `MP.GetLuaMemoryUsage() -> number`: Current memory usage of all states combined, in bytes
+- ADDED `MP.CreateTimedEvent(event,interval_ms)`: Replacement for `CreateThread` - calls the event in the given interval
 
 # v2.3.3
 

include/TLuaEngine.h

@@ -75,12 +75,12 @@ public:
     void RegisterEvent(const std::string& EventName, TLuaStateId StateId, const std::string& FunctionName);
     template <typename... ArgsT>
     [[nodiscard]] std::vector<std::shared_ptr<TLuaResult>> TriggerEvent(const std::string& EventName, TLuaStateId IgnoreId, ArgsT&&... Args) {
-        std::unique_lock Lock(mEventsMutex);
+        std::unique_lock Lock(mLuaEventsMutex);
-        if (mEvents.find(EventName) == mEvents.end()) {
+        if (mLuaEvents.find(EventName) == mLuaEvents.end()) {
             return {};
         }
         std::vector<std::shared_ptr<TLuaResult>> Results;
-        for (const auto& Event : mEvents.at(EventName)) {
+        for (const auto& Event : mLuaEvents.at(EventName)) {
             for (const auto& Function : Event.second) {
                 if (Event.first != IgnoreId) {
                     Results.push_back(EnqueueFunctionCall(Event.first, Function, { TLuaArgTypes { std::forward<ArgsT>(Args) }... }));
@@ -90,6 +90,7 @@ public:
         return Results;
     }
     std::set<std::string> GetEventHandlersForState(const std::string& EventName, TLuaStateId StateId);
+    void CreateTimedEvent(const std::string& EventName, TLuaStateId StateId, size_t IntervalMS);
 
     static constexpr const char* BeamMPFnNotFoundError = "BEAMMP_FN_NOT_FOUND";
 
@@ -134,6 +135,15 @@ private:
         std::recursive_mutex mPathsMutex;
     };
 
+    struct TimedEvent {
+        const std::chrono::high_resolution_clock::duration Duration {};
+        std::chrono::high_resolution_clock::time_point LastCompletion {  };
+        std::string EventName;
+        TLuaStateId StateId;
+        bool Expired();
+        void Reset();
+    };
+
     TNetwork* mNetwork;
     TServer* mServer;
     std::atomic_bool mShutdown { false };
@@ -141,8 +151,10 @@ private:
     std::vector<TLuaPlugin*> mLuaPlugins;
     std::unordered_map<TLuaStateId, std::unique_ptr<StateThreadData>> mLuaStates;
     std::recursive_mutex mLuaStatesMutex;
-    std::unordered_map<std::string /* event name */, std::unordered_map<TLuaStateId, std::set<std::string>>> mEvents;
+    std::unordered_map<std::string /* event name */, std::unordered_map<TLuaStateId, std::set<std::string>>> mLuaEvents;
-    std::recursive_mutex mEventsMutex;
+    std::recursive_mutex mLuaEventsMutex;
+    std::vector<TimedEvent> mTimedEvents;
+    std::recursive_mutex mTimedEventsMutex;
 };
 
 //std::any TriggerLuaEvent(const std::string& Event, bool local, TLuaPlugin* Caller, std::shared_ptr<TLuaArg> arg, bool Wait);

src/TLuaEngine.cpp

@@ -42,9 +42,23 @@ void TLuaEngine::operator()() {
             beammp_lua_error("Calling \"onInit\" on \"" + Future->StateId + "\" failed: " + Future->ErrorMessage);
         }
     }
-    // this thread handles timers
+    // event loop
     while (!mShutdown) {
-        std::this_thread::sleep_for(std::chrono::milliseconds(10));
+        auto Before = std::chrono::high_resolution_clock::now();
+        std::unique_lock Lock(mTimedEventsMutex);
+        for (auto& Timer : mTimedEvents) {
+            if (Timer.Expired()) {
+                Timer.Reset();
+                std::unique_lock Lock2(mLuaStatesMutex);
+                beammp_ignore(mLuaStates[Timer.StateId]->EnqueueFunctionCall("TriggerLocalEvent", { Timer.EventName }));
+            }
+        }
+        // sleep for the remaining time to get to 1ms (our atom duration)
+        if (std::chrono::high_resolution_clock::duration Diff;
+            (Diff = Before - std::chrono::high_resolution_clock::now())
+            < std::chrono::milliseconds(1)) {
+            std::this_thread::sleep_for(Diff);
+        }
     }
 }
 
@@ -138,12 +152,12 @@ void TLuaEngine::EnsureStateExists(TLuaStateId StateId, const std::string& Name,
 }
 
 void TLuaEngine::RegisterEvent(const std::string& EventName, TLuaStateId StateId, const std::string& FunctionName) {
-    std::unique_lock Lock(mEventsMutex);
+    std::unique_lock Lock(mLuaEventsMutex);
-    mEvents[EventName][StateId].insert(FunctionName);
+    mLuaEvents[EventName][StateId].insert(FunctionName);
 }
 
 std::set<std::string> TLuaEngine::GetEventHandlersForState(const std::string& EventName, TLuaStateId StateId) {
-    return mEvents[EventName][StateId];
+    return mLuaEvents[EventName][StateId];
 }
 
 sol::table TLuaEngine::StateThreadData::Lua_TriggerGlobalEvent(const std::string& EventName, sol::variadic_args EventArgs) {
@@ -343,6 +357,9 @@ TLuaEngine::StateThreadData::StateThreadData(const std::string& Name, std::atomi
     });
     MPTable.set_function("Sleep", &LuaAPI::MP::Sleep);
     MPTable.set_function("PrintRaw", &LuaAPI::MP::PrintRaw);
+    MPTable.set_function("CreateTimedEvent", [&](const std::string& EventName, size_t IntervalMS) {
+        mEngine->CreateTimedEvent(EventName, mStateId, IntervalMS);
+    });
     MPTable.set_function("Set", &LuaAPI::MP::Set);
     MPTable.set_function("HttpsGET", [&](const std::string& Host, int Port, const std::string& Target) -> std::tuple<int, std::string> {
         unsigned Status;
@@ -497,6 +514,17 @@ void TLuaEngine::StateThreadData::operator()() {
     }
 }
 
+void TLuaEngine::CreateTimedEvent(const std::string& EventName, TLuaStateId StateId, size_t IntervalMS) {
+    std::unique_lock Lock(mTimedEventsMutex);
+    TimedEvent Event {
+        std::chrono::high_resolution_clock::duration { std::chrono::milliseconds(IntervalMS) },
+        std::chrono::high_resolution_clock::now(),
+        EventName,
+        StateId
+    };
+    mTimedEvents.push_back(std::move(Event));
+}
+
 void TLuaEngine::StateThreadData::AddPath(const fs::path& Path) {
     std::unique_lock Lock(mPathsMutex);
     mPaths.push(Path);
@@ -513,3 +541,12 @@ TLuaChunk::TLuaChunk(std::shared_ptr<std::string> Content, std::string FileName,
     , FileName(FileName)
     , PluginPath(PluginPath) {
 }
+
+bool TLuaEngine::TimedEvent::Expired() {
+    auto Waited = (std::chrono::high_resolution_clock::now() - LastCompletion);
+    return Waited < Duration;
+}
+
+void TLuaEngine::TimedEvent::Reset() {
+    LastCompletion = std::chrono::high_resolution_clock::now();
+}