static T& instance()
{
T * tmp = pInstance_.load(std::memory_order_acquire);
if (tmp == nullptr)
{
std::lock_guard<std::mutex> lock(mutex_);
tmp = pInstance_.load(std::memory_order_relaxed);
if (tmp == nullptr)
{
if (destroyed_)
{
destroyed_ = false;
onDeadReference();
}
else
{
tmp = CreatePolicy<T>::create();
pInstance_.store(tmp, std::memory_order_release);
#ifndef MAPNIK_NO_ATEXIT
// register destruction
std::atexit(&DestroySingleton);
#endif
}
}
}
return *tmp;
}
static T& instance()
{
if (! pInstance_)
{
#ifdef MAPNIK_THREADSAFE
mapnik::scoped_lock lock(mutex_);
#endif
if (! pInstance_)
{
if (destroyed_)
{
destroyed_ = false;
onDeadReference();
}
else
{
pInstance_ = CreatePolicy<T>::create();
// register destruction
std::atexit(&DestroySingleton);
}
}
}
return *pInstance_;
}
PhoenixSingleton* getInstance()
{
if(!pInstance_)
{ if(isDestroyed_) onDeadReference(); }
else createInstance();
return pInstance_;
}
