From 6e0d888d946a0d6a6db7856fcf84730a8118bb82 Mon Sep 17 00:00:00 2001
From: Brett <brettgraham@gmail.com>
Date: Tue, 12 Mar 2024 12:51:40 -0400
Subject: [PATCH 1/3] add python 3.12 ci job

---
 .github/workflows/ci.yml | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index d37a88bb..0291cf65 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -31,7 +31,8 @@ jobs:
         - linux: py39-oldestdeps-cov-xdist
         - linux: py39-xdist
         - linux: py310-xdist
-        - linux: py311-cov-xdist
+        - linux: py311-xdist
+        - linux: py312-cov-xdist
           coverage: codecov
         - macos: py311-xdist
   test_downstream:

From a053db73ca2bfb41b851baf46da94c53429d7b19 Mon Sep 17 00:00:00 2001
From: Brett <brettgraham@gmail.com>
Date: Tue, 12 Mar 2024 12:58:33 -0400
Subject: [PATCH 2/3] use get_context for multiprocessing

---
 src/stcal/jump/jump.py            | 7 ++++---
 src/stcal/ramp_fitting/ols_fit.py | 5 +++--
 2 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/src/stcal/jump/jump.py b/src/stcal/jump/jump.py
index a047ce6e..03405c08 100644
--- a/src/stcal/jump/jump.py
+++ b/src/stcal/jump/jump.py
@@ -391,9 +391,10 @@ def detect_jumps(
             ),
         )
         log.info("Creating %d processes for jump detection ", n_slices)
-        pool = multiprocessing.Pool(processes=n_slices)
-######### JUST FOR DEBUGGING #########################
-#        pool = multiprocessing.Pool(processes=1)
+        ctx = multiprocessing.get_context("forkserver")
+        pool = ctx.Pool(processes=n_slices)
+        ######### JUST FOR DEBUGGING #########################
+        # pool = ctx.Pool(processes=1)
         # Starts each slice in its own process. Starmap allows more than one
         # parameter to be passed.
         real_result = pool.starmap(twopt.find_crs, slices)
diff --git a/src/stcal/ramp_fitting/ols_fit.py b/src/stcal/ramp_fitting/ols_fit.py
index a52e2fba..66d19b76 100644
--- a/src/stcal/ramp_fitting/ols_fit.py
+++ b/src/stcal/ramp_fitting/ols_fit.py
@@ -1,10 +1,10 @@
 #! /usr/bin/env python
 
 import logging
+import multiprocessing
 import time
 import warnings
 from multiprocessing import cpu_count
-from multiprocessing.pool import Pool
 
 import numpy as np
 
@@ -160,7 +160,8 @@ def ols_ramp_fit_multiprocessing(
         ramp_data, buffsize, save_opt, readnoise_2d, gain_2d, weighting, number_slices
     )
 
-    pool = Pool(processes=number_slices)
+    ctx = multiprocessing.get_context("forkserver")
+    pool = ctx.Pool(processes=number_slices)
     pool_results = pool.starmap(ols_ramp_fit_single, slices)
     pool.close()
     pool.join()

From 987e19fa1e0b20142f3c08274628518eddbbaa31 Mon Sep 17 00:00:00 2001
From: Brett <brettgraham@gmail.com>
Date: Tue, 12 Mar 2024 13:04:32 -0400
Subject: [PATCH 3/3] add changelog entry

---
 CHANGES.rst | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/CHANGES.rst b/CHANGES.rst
index cf7bc1f8..6b1162d6 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -4,6 +4,16 @@
 Changes to API
 --------------
 
+jump
+~~~~
+
+- Switch multiprocessing method to ``fork_server``. [#249]
+
+ramp_fitting
+~~~~~~~~~~~~
+
+- Switch multiprocessing method to ``fork_server``. [#249]
+
 Bug Fixes
 ---------