efficient thread-safe singleton in C++

Question

The usual pattern for a singleton class is something like

static Foo &getInst()
{
  static Foo *inst = NULL;
  if(inst == NULL)
    inst = new Foo(...);
         


        

Answer 1

TTBOMK, the only guaranteed thread-safe way to do this without locking would be to initialize all your singletons before you ever start a thread.