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-rwxr-xr-xindra/llcommon/llsingleton.h143
1 files changed, 60 insertions, 83 deletions
diff --git a/indra/llcommon/llsingleton.h b/indra/llcommon/llsingleton.h
index 49d99f2cd0..40002313f1 100755
--- a/indra/llcommon/llsingleton.h
+++ b/indra/llcommon/llsingleton.h
@@ -30,38 +30,6 @@
#include <typeinfo>
#include <boost/noncopyable.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
// you have to do that yourself.
@@ -101,20 +69,23 @@ private:
} EInitState;
// stores pointer to singleton instance
- // and tracks initialization state of singleton
- struct SingletonInstanceData
+ struct SingletonLifetimeManager
{
- EInitState mInitState;
- DERIVED_TYPE* mSingletonInstance;
-
- SingletonInstanceData()
- : mSingletonInstance(NULL),
- mInitState(UNINITIALIZED)
- {}
-
- ~SingletonInstanceData()
+ SingletonLifetimeManager()
+ {
+ construct();
+ }
+
+ static void construct()
{
- if (mInitState != DELETED)
+ sData.mInitState = CONSTRUCTING;
+ sData.mInstance = new DERIVED_TYPE();
+ sData.mInitState = INITIALIZING;
+ }
+
+ ~SingletonLifetimeManager()
+ {
+ if (sData.mInitState != DELETED)
{
deleteSingleton();
}
@@ -124,9 +95,8 @@ private:
public:
virtual ~LLSingleton()
{
- SingletonInstanceData& data = getData();
- data.mSingletonInstance = NULL;
- data.mInitState = DELETED;
+ sData.mInstance = NULL;
+ sData.mInitState = DELETED;
}
/**
@@ -151,50 +121,46 @@ public:
*/
static void deleteSingleton()
{
- delete getData().mSingletonInstance;
- getData().mSingletonInstance = NULL;
- getData().mInitState = DELETED;
+ delete sData.mInstance;
+ sData.mInstance = NULL;
+ sData.mInitState = DELETED;
}
- static SingletonInstanceData& getData()
- {
- // 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()
{
- SingletonInstanceData& data = getData();
+ static SingletonLifetimeManager sLifeTimeMgr;
- if (data.mInitState == CONSTRUCTING)
+ switch (sData.mInitState)
{
+ case UNINITIALIZED:
+ // should never be uninitialized at this point
+ llassert(false);
+ return NULL;
+ case CONSTRUCTING:
llerrs << "Tried to access singleton " << typeid(DERIVED_TYPE).name() << " from singleton constructor!" << llendl;
- }
-
- if (data.mInitState == DELETED)
- {
+ return NULL;
+ case INITIALIZING:
+ // go ahead and flag ourselves as initialized so we can be reentrant during initialization
+ sData.mInitState = INITIALIZED;
+ sData.mInstance->initSingleton();
+ return sData.mInstance;
+ case INITIALIZED:
+ return sData.mInstance;
+ case DELETED:
llwarns << "Trying to access deleted singleton " << typeid(DERIVED_TYPE).name() << " creating new instance" << llendl;
+ SingletonLifetimeManager::construct();
+ sData.mInitState = INITIALIZED;
+ sData.mInstance->initSingleton();
+ return sData.mInstance;
}
-
- if (!data.mSingletonInstance)
- {
- data.mInitState = CONSTRUCTING;
- data.mSingletonInstance = new DERIVED_TYPE();
- data.mInitState = INITIALIZING;
- data.mSingletonInstance->initSingleton();
- data.mInitState = INITIALIZED;
- }
-
- return data.mSingletonInstance;
+
+ return NULL;
+ }
+
+ static DERIVED_TYPE* getIfExists()
+ {
+ return sData.mInstance;
}
// Reference version of getInstance()
@@ -208,18 +174,29 @@ public:
// Use this to avoid accessing singletons before the can safely be constructed
static bool instanceExists()
{
- return getData().mInitState == INITIALIZED;
+ return sData.mInitState == INITIALIZED;
}
// Has this singleton already been deleted?
// Use this to avoid accessing singletons from a static object's destructor
static bool destroyed()
{
- return getData().mInitState == DELETED;
+ return sData.mInitState == DELETED;
}
private:
+
virtual void initSingleton() {}
+
+ struct SingletonData
+ {
+ EInitState mInitState;
+ DERIVED_TYPE* mInstance;
+ };
+ static SingletonData sData;
};
+template<typename T>
+typename LLSingleton<T>::SingletonData LLSingleton<T>::sData;
+
#endif