Use shared_ptr to store plugins (#1640)

examples/client_example/main.cc

@@ -18,7 +18,7 @@ int main()
     {
         auto client = HttpClient::newHttpClient("http://www.baidu.com");
         client->setSockOptCallback([](int fd) {
-            std::cout << "setSockOptCallback" << std::endl;
+            std::cout << "setSockOptCallback:" << fd << std::endl;
 #ifdef __linux__
             int optval = 10;
             ::setsockopt(fd,

lib/inc/drogon/DrClassMap.h

@@ -33,6 +33,7 @@ namespace drogon
 {
 class DrObjectBase;
 using DrAllocFunc = std::function<DrObjectBase *()>;
+using DrSharedAllocFunc = std::function<std::shared_ptr<DrObjectBase>()>;
 
 /**
  * @brief A map class which can create DrObjects from names.
@@ -47,7 +48,8 @@ class DROGON_EXPORT DrClassMap
      * @param func The function which can create a new instance of the class.
      */
     static void registerClass(const std::string &className,
-                              const DrAllocFunc &func);
+                              const DrAllocFunc &func,
+                              const DrSharedAllocFunc &sharedFunc = nullptr);
 
     /**
      * @brief Create a new instance of the class named by className
@@ -57,6 +59,12 @@ class DROGON_EXPORT DrClassMap
      */
     static DrObjectBase *newObject(const std::string &className);
 
+    /**
+     * @brief Get the shared_ptr instance of the class named by className
+     */
+    static std::shared_ptr<DrObjectBase> newSharedObject(
+        const std::string &className);
+
     /**
      * @brief Get the singleton object of the class named by className
      *
@@ -129,7 +137,8 @@ class DROGON_EXPORT DrClassMap
     }
 
   protected:
-    static std::unordered_map<std::string, DrAllocFunc> &getMap();
+    static std::unordered_map<std::string,
+                              std::pair<DrAllocFunc, DrSharedAllocFunc>>
+        &getMap();
 };
-
 }  // namespace drogon

lib/inc/drogon/DrObject.h

@@ -102,8 +102,12 @@ class DrObject : public virtual DrObjectBase
                                 void>::type
         registerClass()
         {
-            DrClassMap::registerClass(className(),
-                                      []() -> DrObjectBase * { return new T; });
+            DrClassMap::registerClass(
+                className(),
+                []() -> DrObjectBase * { return new T; },
+                []() -> std::shared_ptr<DrObjectBase> {
+                    return std::make_shared<T>();
+                });
         }
         template <typename D>
         typename std::enable_if<!std::is_default_constructible<D>::value,

lib/inc/drogon/HttpAppFramework.h

@@ -199,7 +199,26 @@ class DROGON_EXPORT HttpAppFramework : public trantor::NonCopyable
         return pluginPtr;
     }
 
-    /// Get the plugin object registered in the framework
+    /// Get the shared_ptr plugin object registered in the framework
+    /**
+     * @note
+     * This method is usually called after the framework runs.
+     * Calling this method in the initAndStart() method of plugins is also
+     * valid.
+     */
+    template <typename T>
+    std::shared_ptr<T> getSharedPlugin()
+    {
+        static_assert(IsPlugin<T>::value,
+                      "The Template parameter must be a subclass of "
+                      "PluginBase");
+        assert(isRunning());
+        static auto pluginPtr =
+            std::dynamic_pointer_cast<T>(getSharedPlugin(T::classTypeName()));
+        return pluginPtr;
+    }
+
+    /// @brief the plugin object registered in the framework
     /**
      * @param name is the class name of the plugin.
      *
@@ -210,6 +229,17 @@ class DROGON_EXPORT HttpAppFramework : public trantor::NonCopyable
      */
     virtual PluginBase *getPlugin(const std::string &name) = 0;
 
+    /**
+     * @brief Get the shared_ptr plugin object registered in the framework
+     *
+     * @note
+     * This method is usually called after the framework runs.
+     * Calling this method in the initAndStart() method of plugins is also
+     * valid.
+     */
+    virtual std::shared_ptr<PluginBase> getSharedPlugin(
+        const std::string &name) = 0;
+
     /* The following is a series of methods of AOP */
 
     /// Register a beginning advice

lib/inc/drogon/plugins/GlobalFilters.h

@@ -39,7 +39,9 @@ class DROGON_EXPORT GlobalFilters
       public std::enable_shared_from_this<GlobalFilters>
 {
   public:
-    GlobalFilters() = default;
+    GlobalFilters()
+    {
+    }
     void initAndStart(const Json::Value &config) override;
     void shutdown() override;
 
@@ -49,4 +51,4 @@ class DROGON_EXPORT GlobalFilters
     bool regexFlag_{false};
 };
 }  // namespace plugin
-}  // namespace drogon
+}  // namespace drogon

lib/src/DrClassMap.cc

@@ -40,10 +40,12 @@ static std::mutex &getMapMutex()
 }  // namespace drogon
 
 void DrClassMap::registerClass(const std::string &className,
-                               const DrAllocFunc &func)
+                               const DrAllocFunc &func,
+                               const DrSharedAllocFunc &sharedFunc)
 {
     LOG_TRACE << "Register class:" << className;
-    getMap().insert(std::make_pair(className, func));
+    getMap().insert(
+        std::make_pair(className, std::make_pair(func, sharedFunc)));
 }
 
 DrObjectBase *DrClassMap::newObject(const std::string &className)
@@ -51,12 +53,26 @@ DrObjectBase *DrClassMap::newObject(const std::string &className)
     auto iter = getMap().find(className);
     if (iter != getMap().end())
     {
-        return iter->second();
+        return iter->second.first();
     }
     else
         return nullptr;
 }
 
+std::shared_ptr<DrObjectBase> DrClassMap::newSharedObject(
+    const std::string &className)
+{
+    auto iter = getMap().find(className);
+    if (iter != getMap().end())
+    {
+        if (iter->second.second)
+            return iter->second.second();
+        else
+            return std::shared_ptr<DrObjectBase>(iter->second.first());
+    }
+    else
+        return nullptr;
+}
 const std::shared_ptr<DrObjectBase> &DrClassMap::getSingleInstance(
     const std::string &className)
 {
@@ -68,7 +84,7 @@ const std::shared_ptr<DrObjectBase> &DrClassMap::getSingleInstance(
         if (iter != singleInstanceMap.end())
             return iter->second;
     }
-    auto newObj = std::shared_ptr<DrObjectBase>(newObject(className));
+    auto newObj = newSharedObject(className);
     {
         std::lock_guard<std::mutex> lock(mtx);
         auto ret = singleInstanceMap.insert(
@@ -95,8 +111,11 @@ std::vector<std::string> DrClassMap::getAllClassName()
     return ret;
 }
 
-std::unordered_map<std::string, DrAllocFunc> &DrClassMap::getMap()
+std::unordered_map<std::string, std::pair<DrAllocFunc, DrSharedAllocFunc>>
+    &DrClassMap::getMap()
 {
-    static std::unordered_map<std::string, DrAllocFunc> map;
+    static std::unordered_map<std::string,
+                              std::pair<DrAllocFunc, DrSharedAllocFunc>>
+        map;
     return map;
 }

lib/src/HttpAppFrameworkImpl.cc

@@ -348,6 +348,12 @@ PluginBase *HttpAppFrameworkImpl::getPlugin(const std::string &name)
 {
     return pluginsManagerPtr_->getPlugin(name);
 }
+
+std::shared_ptr<PluginBase> HttpAppFrameworkImpl::getSharedPlugin(
+    const std::string &name)
+{
+    return pluginsManagerPtr_->getSharedPlugin(name);
+}
 void HttpAppFrameworkImpl::addPlugin(
     const std::string &name,
     const std::vector<std::string> &dependencies,

lib/src/HttpAppFrameworkImpl.h

@@ -57,6 +57,8 @@ class HttpAppFrameworkImpl final : public HttpAppFramework
     }
 
     PluginBase *getPlugin(const std::string &name) override;
+    std::shared_ptr<PluginBase> getSharedPlugin(
+        const std::string &name) override;
     void addPlugins(const Json::Value &configs);
     void addPlugin(const std::string &name,
                    const std::vector<std::string> &dependencies,

lib/src/PluginsManager.cc

@@ -88,16 +88,14 @@ void PluginsManager::initializeAllPlugins(
 }
 void PluginsManager::createPlugin(const std::string &pluginName)
 {
-    auto *p = DrClassMap::newObject(pluginName);
-    auto *pluginPtr = dynamic_cast<PluginBase *>(p);
+    auto pluginPtr = std::dynamic_pointer_cast<PluginBase>(
+        DrClassMap::newSharedObject(pluginName));
     if (!pluginPtr)
     {
-        if (p)
-            delete p;
         LOG_ERROR << "Plugin " << pluginName << " undefined!";
         return;
     }
-    pluginsMap_[pluginName].reset(pluginPtr);
+    pluginsMap_[pluginName] = pluginPtr;
 }
 PluginBase *PluginsManager::getPlugin(const std::string &pluginName)
 {
@@ -107,4 +105,15 @@ PluginBase *PluginsManager::getPlugin(const std::string &pluginName)
         return iter->second.get();
     }
     return nullptr;
+}
+
+std::shared_ptr<PluginBase> PluginsManager::getSharedPlugin(
+    const std::string &pluginName)
+{
+    auto iter = pluginsMap_.find(pluginName);
+    if (iter != pluginsMap_.end())
+    {
+        return iter->second;
+    }
+    return nullptr;
 }

lib/src/PluginsManager.h

@@ -18,7 +18,7 @@
 
 namespace drogon
 {
-using PluginBasePtr = std::unique_ptr<PluginBase>;
+using PluginBasePtr = std::shared_ptr<PluginBase>;
 
 class PluginsManager : trantor::NonCopyable
 {
@@ -29,6 +29,8 @@ class PluginsManager : trantor::NonCopyable
 
     PluginBase *getPlugin(const std::string &pluginName);
 
+    std::shared_ptr<PluginBase> getSharedPlugin(const std::string &pluginName);
+
     ~PluginsManager();
 
   private:

trantor

@@ -1 +1 @@
-Subproject commit 60fb0a0577eb06c1725e927c8ef3d549611090c0
+Subproject commit 8601bb91130f4254f9cc710d80860f4c210c8b58