//========= Copyright Valve Corporation, All rights reserved. ============//
//
// Purpose:
//
// $NoKeywords: $
//
//=============================================================================//

// Initializers are a way to register your object to be initialized at startup
// time. They're a good way to have global variables without worrying about
// dependent constructors being called. They also make it so init code doesn't
// depend on the global objects it's initializing.

// To use initializers, just use REGISTER_INITIALIZER to register your global
// variable like this: class SomeClass {....} SomeClass *g_pSomeClassSingleton =
// NULL; REGISTER_INITIALIZER(SomeClass, &g_pSomeClassSingleton);

#ifndef INITIALIZER_H
#define INITIALIZER_H

typedef void *(*CreateInitializerObjectFn)();
typedef void (*DeleteInitializerObjectFn)(void *ptr);

class Initializer {
   public:
    Initializer(void **pVar, CreateInitializerObjectFn createFn,
                DeleteInitializerObjectFn deleteFn);

    // Allocates all the global objects.
    static bool InitializeAllObjects();

    // Free all the global objects.
    static void FreeAllObjects();

   private:
    static Initializer *s_pInitializers;

    void **m_pVar;
    CreateInitializerObjectFn m_CreateFn;
    DeleteInitializerObjectFn m_DeleteFn;
    Initializer *m_pNext;
};

#define REGISTER_INITIALIZER(className, varPointer)                \
    static void *__Initializer__Create##className##Fn() {          \
        return new className;                                      \
    }                                                              \
    static void *__Initializer__Delete##className##Fn(void *ptr) { \
        delete (className *)ptr;                                   \
    }                                                              \
    static Initializer g_Initializer_##className##(                \
        varPointer, __Initializer__Create##className##Fn,          \
        __Initializer__Delete##className##Fn);

#define REGISTER_FUNCTION_INITIALIZER(functionName)          \
    static void *__Initializer__Create##functionName##Fn() { \
        functionName();                                      \
        return 0;                                            \
    }                                                        \
    static Initializer g_Initializer_##functionName##(       \
        0, __Initializer__Create##functionName##Fn, 0);

#endif