Hands-On Design Patterns and Best Practices with Julia

Chapter 11

What technique can we use to implement the abstract factory pattern?

To implement the abstract factory pattern, we can create a hierarchy of abstract types. Then, we can implement concrete functions that take a singleton type in the argument. By way of multiple dispatches, we should be able to call the right function for the right platform or environment.  

How do we avoid a singleton from being initialized multiple times in a multithreaded application?

To avoid multiple initializations of a singleton, we can use a reentrant lock to synchronize the threads. The first thread would be able to obtain the lock and initialize the singleton, while the other threads should wait until the initialization is finished. The lock must be released ...