diff options
Diffstat (limited to 'include/astra/Singleton.h')
| -rw-r--r-- | include/astra/Singleton.h | 28 |
1 files changed, 19 insertions, 9 deletions
diff --git a/include/astra/Singleton.h b/include/astra/Singleton.h index a256187..9d3c088 100644 --- a/include/astra/Singleton.h +++ b/include/astra/Singleton.h @@ -45,11 +45,7 @@ class Singleton { public: // constructor - Singleton() { - assert(!m_singleton); - int offset = (uintptr_t)(T*)1 - (uintptr_t)(Singleton<T>*)(T*)1; - m_singleton = (T*)((uintptr_t)this + offset); - }; + Singleton() { } // destructor virtual ~Singleton() { @@ -57,15 +53,17 @@ class Singleton { m_singleton = 0; } + static void construct(); + // get singleton static T& getSingleton() { if (!m_singleton) - m_singleton = new T(); + construct(); return *m_singleton; } static T* getSingletonPtr() { if (!m_singleton) - m_singleton = new T(); + construct(); return m_singleton; } @@ -76,11 +74,23 @@ class Singleton { }; -#define DEFINE_SINGLETON(T) template<> T* Singleton<T >::m_singleton = 0 +// We specifically avoid defining construct() in the header. +// That way, the call to new is always executed by code inside libastra. +// This avoids the situation where a singleton gets created by a copy +// of the constructor linked into an object file outside of libastra, such +// as a .mex file, which would then also cause the vtable to be outside of +// libastra. This situation would cause issues when .mex files are unloaded. + +#define DEFINE_SINGLETON(T) \ +template<> void Singleton<T >::construct() { assert(!m_singleton); m_singleton = new T(); } \ +template<> T* Singleton<T >::m_singleton = 0 + // This is a hack to support statements like // DEFINE_SINGLETON2(CTemplatedClass<C1, C2>); -#define DEFINE_SINGLETON2(A,B) template<> A,B* Singleton<A,B >::m_singleton = 0 +#define DEFINE_SINGLETON2(A,B) \ +template<> void Singleton<A,B >::construct() { assert(!m_singleton); m_singleton = new A,B(); } \ +template<> A,B* Singleton<A,B >::m_singleton = 0 } // end namespace |