split functionality file across new module as was getting too long on its own. All functions remian the same, but imports will need to be updated.

functionality/process_io.py

@@ -0,0 +1,41 @@
+"""
+This file contains functions for reading and writing between processes.
+
+Author(s): David Marchant
+"""
+
+from os import name as osName
+from typing import List
+
+from multiprocessing.connection import Connection, wait as multi_wait
+# Need to import additional Connection type for Windows machines
+if osName == 'nt':
+    from multiprocessing.connection import PipeConnection
+from multiprocessing.queues import Queue
+from core.correctness.vars import VALID_CHANNELS
+
+
+def wait(inputs:List[VALID_CHANNELS])->List[VALID_CHANNELS]:
+    if osName == 'nt':
+        return wait_windows(inputs)
+    return wait_linux(inputs)
+
+def wait_windows(inputs:List[VALID_CHANNELS])->List[VALID_CHANNELS]:
+    all_connections = [i for i in inputs if type(i) is Connection] \
+        + [i for i in inputs if type(i) is PipeConnection] \
+        + [i._reader for i in inputs if type(i) is Queue]
+    ready = multi_wait(all_connections)
+    ready_inputs = [i for i in inputs if \
+        (type(i) is Connection and i in ready) \
+        or (type(i) is PipeConnection and i in ready) \
+        or (type(i) is Queue and i._reader in ready)]
+    return ready_inputs
+
+def wait_linux(inputs:List[VALID_CHANNELS])->List[VALID_CHANNELS]:
+    all_connections = [i for i in inputs if type(i) is Connection] \
+        + [i._reader for i in inputs if type(i) is Queue]
+    ready = multi_wait(all_connections)
+    ready_inputs = [i for i in inputs if \
+        (type(i) is Connection and i in ready) \
+        or (type(i) is Queue and i._reader in ready)]
+    return ready_inputs