Island: Use read/write lock in FileRepositoryLockingDecorator

monkey/monkey_island/cc/repository/file_repository_locking_decorator.py

@@ -1,30 +1,27 @@
-from multiprocessing import Lock
 from typing import BinaryIO
 
-from . import IFileRepository
+from readerwriterlock import rwlock
 
-# TODO: Use a read-write lock. See:
-#           - https://pypi.org/project/readerwriterlock/
-#           - https://www.oreilly.com/library/view/python-cookbook/0596001673/ch06s04.html
+from . import IFileRepository
 
 
 class FileRepositoryLockingDecorator(IFileRepository):
     def __init__(self, file_repository: IFileRepository):
         self._file_repository = file_repository
-        self._lock = Lock()
+        self._rwlock = rwlock.RWLockFair()
 
     def save_file(self, unsafe_file_name: str, file_contents: BinaryIO):
-        with self._lock:
+        with self._rwlock.gen_wlock():
             return self._file_repository.save_file(unsafe_file_name, file_contents)
 
     def open_file(self, unsafe_file_name: str) -> BinaryIO:
-        with self._lock:
+        with self._rwlock.gen_rlock():
             return self._file_repository.open_file(unsafe_file_name)
 
     def delete_file(self, unsafe_file_name: str):
-        with self._lock:
+        with self._rwlock.gen_wlock():
             return self._file_repository.delete_file(unsafe_file_name)
 
     def delete_all_files(self):
-        with self._lock:
+        with self._rwlock.gen_wlock():
             return self._file_repository.delete_all_files()