feat: ✨ PYTHON_INJECTION_THREADSAFE env var

Author: remimd

README.md

@@ -64,8 +64,14 @@ if __name__ == "__main__":
 
 ## Resources
 
-> ⚠️ The package isn't threadsafe, for better performance in single-threaded applications and those using `asyncio`.
-> So remember to use `threading.Lock` if you're writing a multithreaded program.
+> ⚠️ The package isn't threadsafe by default, for better performance in single-threaded applications and those using
+> `asyncio`.
+> 
+> Non-threadsafe functions are those that resolve dependencies or define scopes. They all come with an optional 
+> parameter `threadsafe`.
+> 
+> You can set `PYTHON_INJECTION_THREADSAFE=1` in environment variables to make the package fully threadsafe. The 
+> environment variable is resolved at the **Python module level**, so be careful if the variable is defined dynamically.
 
 * [**Basic usage**](https://github.com/100nm/python-injection/tree/prod/documentation/basic-usage.md)
 * [**Scoped dependencies**](https://github.com/100nm/python-injection/tree/prod/documentation/scoped-dependencies.md)

injection/_core/common/threading.py

@@ -1,7 +1,11 @@
 from contextlib import nullcontext
+from os import getenv
 from threading import RLock
-from typing import Any, ContextManager
+from typing import Any, ContextManager, Final
+
+_PYTHON_INJECTION_THREADSAFE: Final[bool] = bool(getenv("PYTHON_INJECTION_THREADSAFE"))
 
 
 def get_lock(threadsafe: bool | None = None) -> ContextManager[Any]:
-    return RLock() if threadsafe else nullcontext()
+    cond = _PYTHON_INJECTION_THREADSAFE if threadsafe is None else threadsafe
+    return RLock() if cond else nullcontext()