Core/Game: Add a dynamic script reloader which reloads scripts modules on changes.

* is responsible for registering plain modules.
* requires compilation with the `WITH_DYNAMIC_LINKING` flag.
* requires further support of the ScriptMgr.

src/server/game/Scripting/ScriptMgr.cpp

@@ -263,12 +263,19 @@ void ScriptMgr::Initialize()
 
     FillSpellSummary();
 
+    // Load core script systems
+    // SmartAI
+    BeginScriptContext("core scripts");
     AddSC_SmartScripts();
+    FinishScriptContext();
 
+    // Load all static linked scripts through the script loader function.
+    BeginScriptContext("static scripts");
     ASSERT(_script_loader_callback,
            "Script loader callback wasn't registered!");
 
     _script_loader_callback();
+    FinishScriptContext();
 
 #ifdef SCRIPTS
     for (std::string const& scriptName : UnusedScriptNames)
@@ -280,6 +287,21 @@ void ScriptMgr::Initialize()
     TC_LOG_INFO("server.loading", ">> Loaded %u C++ scripts in %u ms", GetScriptCount(), GetMSTimeDiffToNow(oldMSTime));
 }
 
+void ScriptMgr::BeginScriptContext(std::string const& context)
+{
+    _currentContext = context;
+}
+
+void ScriptMgr::FinishScriptContext()
+{
+    _currentContext.clear();
+}
+
+void ScriptMgr::ReleaseScriptContext(std::string const& /*context*/)
+{
+    // ToDo
+}
+
 void ScriptMgr::Unload()
 {
     #define SCR_CLEAR(T) \

src/server/game/Scripting/ScriptMgr.h

@@ -837,9 +837,6 @@ class TC_GAME_API GroupScript : public ScriptObject
         virtual void OnDisband(Group* /*group*/) { }
 };
 
-// Placed here due to ScriptRegistry::AddScript dependency.
-#define sScriptMgr ScriptMgr::instance()
-
 // namespace
 // {
     typedef std::list<std::string> UnusedScriptNamesContainer;
@@ -855,12 +852,13 @@ class TC_GAME_API ScriptMgr
         ScriptMgr();
         virtual ~ScriptMgr();
 
+        void FillSpellSummary();
+        void LoadDatabase();
+
     public: /* Initialization */
         static ScriptMgr* instance();
 
         void Initialize();
-        void LoadDatabase();
-        void FillSpellSummary();
 
         const char* ScriptsVersion() const { return "Integrated Trinity Scripts"; }
 
@@ -876,6 +874,12 @@ class TC_GAME_API ScriptMgr
             _script_loader_callback = script_loader_callback;
         }
 
+    public: /* Script contexts */
+        void BeginScriptContext(std::string const& context);
+        void FinishScriptContext();
+
+        void ReleaseScriptContext(std::string const& context);
+
     public: /* Unloading */
 
         void Unload();
@@ -1106,13 +1110,16 @@ class TC_GAME_API ScriptMgr
         bool IsScriptScheduled() const { return _scheduledScripts > 0; }
 
     private:
-
         uint32 _scriptCount;
 
         //atomic op counter for active scripts amount
         std::atomic<uint32> _scheduledScripts;
 
         ScriptLoaderCallbackType _script_loader_callback;
+
+        std::string _currentContext;
 };
 
+#define sScriptMgr ScriptMgr::instance()
+
 #endif

src/server/game/Scripting/ScriptReloadMgr.h

@@ -0,0 +1,82 @@
+/*
+ * Copyright (C) 2008-2016 TrinityCore <http://www.trinitycore.org/>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef SCRIPT_RELOADER_H
+#define SCRIPT_RELOADER_H
+
+#include <memory>
+#include <string>
+#include "Define.h"
+#include <boost/filesystem/path.hpp>
+
+/// Represents a strong reference to a dynamic library which
+/// provides C++ scripts. As long as one reference to the library exists
+/// the library is kept loaded in the server, which makes it possible to lazy
+/// unload several script types on demand (like SpellScripts), and to
+/// provide multiple versions of the same script to the script factories.
+///
+/// Acquire a new reference through using:
+/// `ScriptReloadMgr::AcquireModuleReferenceOfContext`
+class ModuleReference
+{
+public:
+    virtual ~ModuleReference() { }
+
+    /// Returns the git revision hash of the referenced script module
+    virtual char const* GetScriptModuleRevisionHash() const = 0;
+    /// Returns the name of the referenced script module
+    virtual char const* GetScriptModule() const = 0;
+    /// Returns the path to the script module
+    virtual boost::filesystem::path const& GetModulePath() const = 0;
+};
+
+/// Provides the whole physical dynamic library unloading capability.
+/// Loads, Reloads and Unloads dynamic libraries on changes and
+/// informs the ScriptMgr about changes which were made.
+/// The ScriptReloadMgr is also responsible for watching the source directory
+/// and to invoke a build on changes.
+class TC_GAME_API ScriptReloadMgr
+{
+protected:
+    ScriptReloadMgr() { }
+
+public:
+    virtual ~ScriptReloadMgr() { }
+
+    /// Initializes the ScriptReloadMgr
+    virtual void Initialize() { }
+
+    /// Needs to be called periodically to check for updates on script modules.
+    /// Expects to be invoked in a thread safe way which means it's required that
+    /// the current thread is the only one which accesses the world data.
+    virtual void Update() { }
+
+    /// Unloads the ScriptReloadMgr
+    virtual void Unload() { }
+
+    /// Returns an owning reference to the current module of the given context
+    static std::shared_ptr<ModuleReference> AcquireModuleReferenceOfContext(
+        std::string const& context);
+
+    /// Returns the unique ScriptReloadMgr singleton instance
+    static ScriptReloadMgr* instance();
+};
+
+#define sScriptReloadMgr ScriptReloadMgr::instance()
+
+#endif // SCRIPT_RELOADER_H
+

src/server/game/World/World.cpp

@@ -54,6 +54,7 @@
 #include "PoolMgr.h"
 #include "GitRevision.h"
 #include "ScriptMgr.h"
+#include "ScriptReloadMgr.h"
 #include "SkillDiscovery.h"
 #include "SkillExtraItems.h"
 #include "SmartAI.h"
@@ -1385,9 +1386,18 @@ void World::LoadConfigSettings(bool reload)
     m_bool_configs[CONFIG_CALCULATE_CREATURE_ZONE_AREA_DATA] = sConfigMgr->GetBoolDefault("Calculate.Creature.Zone.Area.Data", false);
     m_bool_configs[CONFIG_CALCULATE_GAMEOBJECT_ZONE_AREA_DATA] = sConfigMgr->GetBoolDefault("Calculate.Gameoject.Zone.Area.Data", false);
 
+
     // prevent character rename on character customization
     m_bool_configs[CONFIG_PREVENT_RENAME_CUSTOMIZATION] = sConfigMgr->GetBoolDefault("PreventRenameCharacterOnCustomization", false);
 
+    // HotSwap
+    m_bool_configs[CONFIG_HOTSWAP_ENABLED] = sConfigMgr->GetBoolDefault("HotSwap.Enabled", true);
+    m_bool_configs[CONFIG_HOTSWAP_RECOMPILER_ENABLED] = sConfigMgr->GetBoolDefault("HotSwap.EnableReCompiler", true);
+    m_bool_configs[CONFIG_HOTSWAP_EARLY_TERMINATION_ENABLED] = sConfigMgr->GetBoolDefault("HotSwap.EnableEarlyTermination", true);
+    m_bool_configs[CONFIG_HOTSWAP_BUILD_FILE_RECREATION_ENABLED] = sConfigMgr->GetBoolDefault("HotSwap.EnableBuildFileRecreation", true);
+    m_bool_configs[CONFIG_HOTSWAP_INSTALL_ENABLED] = sConfigMgr->GetBoolDefault("HotSwap.EnableInstall", true);
+    m_bool_configs[CONFIG_HOTSWAP_PREFIX_CORRECTION_ENABLED] = sConfigMgr->GetBoolDefault("HotSwap.EnablePrefixCorrection", true);
+
     // call ScriptMgr if we're reloading the configuration
     if (reload)
         sScriptMgr->OnConfigLoad(reload);
@@ -1891,6 +1901,7 @@ void World::SetInitialWorldSettings()
     TC_LOG_INFO("server.loading", "Initializing Scripts...");
     sScriptMgr->Initialize();
     sScriptMgr->OnConfigLoad(false);                                // must be done after the ScriptMgr has been properly initialized
+    sScriptReloadMgr->Initialize();
 
     TC_LOG_INFO("server.loading", "Validating spell scripts...");
     sObjectMgr->ValidateSpellScripts();
@@ -1926,6 +1937,8 @@ void World::SetInitialWorldSettings()
 
     m_timers[WUPDATE_PINGDB].SetInterval(getIntConfig(CONFIG_DB_PING_INTERVAL)*MINUTE*IN_MILLISECONDS);    // Mysql ping time in minutes
 
+    m_timers[WUPDATE_CHECK_FILECHANGES].SetInterval(500);
+
     m_timers[WUPDATE_GUILDSAVE].SetInterval(getIntConfig(CONFIG_GUILD_SAVE_INTERVAL) * MINUTE * IN_MILLISECONDS);
 
     //to set mailtimer to return mails every day between 4 and 5 am
@@ -2182,6 +2195,13 @@ void World::Update(uint32 diff)
         m_timers[WUPDATE_AHBOT].Reset();
     }
 
+    /// <li> Handle file changes
+    if (m_timers[WUPDATE_CHECK_FILECHANGES].Passed())
+    {
+        sScriptReloadMgr->Update();
+        m_timers[WUPDATE_CHECK_FILECHANGES].Reset();
+    }
+
     /// <li> Handle session updates when the timer has passed
     ResetTimeDiffRecord();
     UpdateSessions(diff);

src/server/game/World/World.h

@@ -91,6 +91,7 @@ enum WorldTimers
     WUPDATE_AHBOT,
     WUPDATE_PINGDB,
     WUPDATE_GUILDSAVE,
+    WUPDATE_CHECK_FILECHANGES,
     WUPDATE_COUNT
 };
 
@@ -178,6 +179,12 @@ enum WorldBoolConfigs
     CONFIG_BASEMAP_LOAD_GRIDS,
     CONFIG_INSTANCEMAP_LOAD_GRIDS,
     CONFIG_PREVENT_RENAME_CUSTOMIZATION,
+    CONFIG_HOTSWAP_ENABLED,
+    CONFIG_HOTSWAP_RECOMPILER_ENABLED,
+    CONFIG_HOTSWAP_EARLY_TERMINATION_ENABLED,
+    CONFIG_HOTSWAP_BUILD_FILE_RECREATION_ENABLED,
+    CONFIG_HOTSWAP_INSTALL_ENABLED,
+    CONFIG_HOTSWAP_PREFIX_CORRECTION_ENABLED,
     BOOL_CONFIG_VALUE_COUNT
 };
 

src/server/worldserver/Main.cpp

@@ -35,6 +35,7 @@
 #include "InstanceSaveMgr.h"
 #include "ObjectAccessor.h"
 #include "ScriptMgr.h"
+#include "ScriptReloadMgr.h"
 #include "ScriptLoader.h"
 #include "OutdoorPvP/OutdoorPvPMgr.h"
 #include "BattlegroundMgr.h"
@@ -280,6 +281,7 @@ extern int main(int argc, char** argv)
     sOutdoorPvPMgr->Die();
     sMapMgr->UnloadAll();                     // unload all grids (including locked in memory)
     sScriptMgr->Unload();
+    sScriptReloadMgr->Unload();
 
     // set server offline
     LoginDatabase.DirectPExecute("UPDATE realmlist SET flag = flag | %u WHERE id = '%d'", REALM_FLAG_OFFLINE, realm.Id.Realm);

src/server/worldserver/worldserver.conf.dist

@@ -12,6 +12,7 @@
 #    SERVER LOGGING
 #    SERVER SETTINGS
 #    UPDATE SETTINGS
+#    HOTSWAP SETTINGS
 #    WARDEN SETTINGS
 #    PLAYER INTERACTION
 #    CREATURE SETTINGS
@@ -1261,6 +1262,78 @@ Updates.CleanDeadRefMaxCount = 3
 #
 ###################################################################################################
 
+###################################################################################################
+# HOTSWAP SETTINGS
+#
+#    HotSwap.Enabled (Requires compilation with DYNAMIC_LINKING=1)
+#        Description: Enables dynamic script hotswapping.
+#                     Reloads scripts on changes.
+#        Default:     1 - (Enabled)
+#                     0 - (Disabled)
+
+HotSwap.Enabled = 1
+
+#
+#    HotSwap.ScriptDir
+#        Description: Directory containing the script shared libraries (.dll/.so).
+#        Example:     "/usr/local/scripts"
+#        Default:     "scripts"
+
+HotSwap.ScriptDir = "scripts"
+
+#    HotSwap.EnableReCompiler
+#        Description: Enables the dynamic script recompiler.
+#                     Watches your script source directories and recompiles the
+#                     script modules on changes.
+#        Default:     0 - (Disabled)
+#                     1 - (Enabled)
+
+HotSwap.EnableReCompiler = 1
+
+#    HotSwap.EnableEarlyTermination
+#        Description: Terminate the build of a module when an associated
+#                     source file was changed meanwhile.
+#        Default:     1 - (Enabled)
+#                     0 - (Disabled)
+
+HotSwap.EnableEarlyTermination = 1
+
+#    HotSwap.EnableBuildFileRecreation
+#        Description: Recreate build files when sources to a module
+#                     were added or removed.
+#        Default:     1 - (Enabled)
+#                     0 - (Disabled)
+
+HotSwap.EnableBuildFileRecreation = 1
+
+#
+#    HotSwap.EnableInstall
+#        Description: Enables cmake install after automatic builds have finished
+#        Default:     1 - (Enabled)
+#                     0 - (Disabled)
+
+HotSwap.EnableInstall = 1
+
+#
+#    HotSwap.EnablePrefixCorrection
+#        Description: Allows the core to automatic set the CMAKE_INSTALL_PREFIX
+#                     to it's current location in the filesystem.
+#        Default:     1 - (Enabled)
+#                     0 - (Disabled)
+
+HotSwap.EnablePrefixCorrection = 1
+
+#    HotSwap.ReCompilerBuildType
+#        Description: Defines the build type of the builds invoked by the recompiler.
+#        Default:     "" - Built-in build type of the module is used.
+#                     "Release" - Release builds only
+#                     "Debug" - Debug builds only
+
+HotSwap.ReCompilerBuildType = ""
+
+#
+###################################################################################################
+
 ###################################################################################################
 # WARDEN SETTINGS
 #
@@ -3622,6 +3695,7 @@ Logger.sql.updates=3,Console Server
 #Logger.rbac=3,Console Server
 #Logger.scripts=3,Console Server
 #Logger.scripts.ai=3,Console Server
+#Logger.scripts.hotswap=3,Console Server
 #Logger.server.authserver=3,Console Server
 #Logger.spells=3,Console Server
 #Logger.spells.periodic=3,Console Server