From 9eb2e5d4133271592e68b09b8f25ea4cf607ff77 Mon Sep 17 00:00:00 2001
From: Kevin F <beardog@mailbox.org>
Date: Thu, 12 Jan 2023 21:42:22 -0600
Subject: [PATCH] Added multiprocess wrapper to do simple function calls in a
 seperate process

---
 src/utils/multiproc.py | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)
 create mode 100644 src/utils/multiproc.py

diff --git a/src/utils/multiproc.py b/src/utils/multiproc.py
new file mode 100644
index 00000000..661c15dc
--- /dev/null
+++ b/src/utils/multiproc.py
@@ -0,0 +1,31 @@
+from typing import Callable
+import multiprocessing
+import time
+
+
+def _compute(q: multiprocessing.Queue, func: Callable, *args, **kwargs):
+    q.put(func(*args, **kwargs))
+
+def subprocess_compute(func: Callable, wallclock_timeout: int, *args, **kwargs):
+    """
+    Call func in a subprocess, and return the result. Set wallclock_timeout to <= 0 to disable
+    Raises TimeoutError if the function does not return in time
+    Raises ChildProcessError if the subprocess dies before returning
+    """
+    q = multiprocessing.Queue()
+    p = multiprocessing.Process(
+        target=_compute, args=(q, func, *args), kwargs=kwargs, daemon=True)
+    wallclock_timeout = max(wallclock_timeout, 0)
+
+    p.start()
+    start = time.time()
+    while True:
+        try:
+            return q.get(timeout=1)
+        except multiprocessing.queues.Empty:
+            if not p.is_alive():
+                raise ChildProcessError("Process died before returning")
+            if wallclock_timeout:
+                if time.time() - start >= wallclock_timeout:
+                    raise TimeoutError("Process did not return in time")
+