diff options
Diffstat (limited to 'indra/llcommon/llsingleton.h')
| -rw-r--r-- | indra/llcommon/llsingleton.h | 47 |
1 files changed, 45 insertions, 2 deletions
diff --git a/indra/llcommon/llsingleton.h b/indra/llcommon/llsingleton.h index 2e7d845bf7..f55fafadd8 100644 --- a/indra/llcommon/llsingleton.h +++ b/indra/llcommon/llsingleton.h @@ -33,7 +33,41 @@ #include "llerror.h" // *TODO: eliminate this +#include <typeinfo> #include <boost/noncopyable.hpp> +#include <boost/any.hpp> + +/// @brief A global registry of all singletons to prevent duplicate allocations +/// across shared library boundaries +class LL_COMMON_API LLSingletonRegistry { + private: + typedef std::map<std::string, void *> TypeMap; + static TypeMap * sSingletonMap; + + static void checkInit() + { + if(sSingletonMap == NULL) + { + sSingletonMap = new TypeMap(); + } + } + + public: + template<typename T> static void * & get() + { + std::string name(typeid(T).name()); + + checkInit(); + + // the first entry of the pair returned by insert will be either the existing + // iterator matching our key, or the newly inserted NULL initialized entry + // see "Insert element" in http://www.sgi.com/tech/stl/UniqueAssociativeContainer.html + TypeMap::iterator result = + sSingletonMap->insert(std::make_pair(name, (void*)NULL)).first; + + return result->second; + } +}; // LLSingleton implements the getInstance() method part of the Singleton // pattern. It can't make the derived class constructors protected, though, so @@ -107,8 +141,17 @@ public: static SingletonInstanceData& getData() { - static SingletonInstanceData data; - return data; + // this is static to cache the lookup results + static void * & registry = LLSingletonRegistry::get<DERIVED_TYPE>(); + + // *TODO - look into making this threadsafe + if(NULL == registry) + { + static SingletonInstanceData data; + registry = &data; + } + + return *static_cast<SingletonInstanceData *>(registry); } static DERIVED_TYPE* getInstance() |