Add FFI Global Initializer pattern

docs/creation/ffi-global-initializer.md

@@ -0,0 +1,42 @@
+---
+hide:
+  - toc
+---
+
+# FFI Global Initializer
+
+## Problem
+
+You are working with a library via [Pony's C-FFI](https://tutorial.ponylang.io/c-ffi/) and need to initialize the library before you can use it. And you'd like to do this initialization once and only once.
+
+## Solution
+
+Pony's primitives can serve a variety of design purposes. Here we will use a primitive to initialize our imaginary C library.
+
+```pony
+use @magic_global_initialization[None]()
+
+primitive LibraryInitializer
+  fun _init() =>
+    @magic_global_initialization()
+```
+
+## Discussion
+
+Only a single instance of a Pony `primitive` will exist in our binary. User defined primitives are singletons. We can combine this with the fact that primitives have an `_init` function that is called when the primitive is created.
+
+Wrapping our "should only be done once" initialization code in a primitive's `_init` method is a good way to ensure that the initialization code is only run once. It is important to note that this approach doesn't protect you from someone mistakenly calling the initializer via C-FFI directly again,
+
+If we need to teardown the library, we can add a `_final` method to `LibraryInitializer` which will be executed on program shutdown.
+
+```pony
+use @magic_global_initialization[None]()
+use @magic_global_shutdown[None]()
+
+primitive LibraryInitializer
+  fun _init() =>
+    @magic_global_initialization()
+
+  fun _final() =>
+    @magic_global_shutdown()
+```

mkdocs.yml

@@ -84,6 +84,7 @@ nav:
     - Notifier: 'code-sharing/notifier.md'
   - Creation Patterns:
     - Overview: 'creation/index.md'
+    - FFI Global Initializer: 'creation/ffi-global-initializer.md'
     - Static Constructor: 'creation/static-constructor.md'
     - Supply Chain: 'creation/supply-chain.md'
   - Data Sharing Patterns: