Merge pull request #176 from DiamondLightSource/aioca_1.8_fixes

Fixes for aioca 1.8.*

.github/workflows/code.yml

@@ -95,7 +95,11 @@ jobs:
         env:
           CIBW_BUILD: ${{ matrix.python }}*64
           CIBW_TEST_EXTRAS: dev
-          CIBW_TEST_COMMAND: pytest {project}/tests --cov-report xml:${{ matrix.cov_file }} --junit-xml=${{ matrix.results_file }}
+          # Added a sleep command afterwards to let all cleanup finish; sometimes
+          # cibuildwheel reports it cannot clean up the temp dir used for testing,
+          # and fails the build. Sleeping seems to give pytest enough time to
+          # fully clean up.
+          CIBW_TEST_COMMAND: pytest {project}/tests --cov-report xml:${{ matrix.cov_file }} --junit-xml=${{ matrix.results_file }} && sleep 2
           # Run with faulthandler and -s in the hope we get a stack trace on seg fault on windows...
           CIBW_TEST_COMMAND_WINDOWS: python -X faulthandler -m pytest -s {project}/tests --cov-report xml:${{ matrix.cov_file }} --junit-xml=${{ matrix.results_file }}
           # Disable auditwheel as it isn't compatible with setuptools_dso approach

tests/conftest.py

@@ -6,9 +6,20 @@
 import string
 import subprocess
 import sys
+from packaging.version import Version
 from typing import Any
 import pytest
 
+# It is necessary to ensure we always import cothread.catools before aioca as
+# doing this import will cause an EPICS context to be created, and it will also
+# register an atexit function to delete it.
+# If we were to import aioca first it would create an EPICS context, note it has
+# created it, then try to delete it in its own atexit function which will
+# collide with cothread's attempts to do the same (despite the fact in this
+# configuration cothread did not create the context)
+if os.name != "nt":
+    import cothread.catools
+
 from softioc import builder
 from softioc.builder import ClearRecords, SetDeviceName, GetRecordNames
 
@@ -73,12 +84,17 @@ def cothread_ioc():
 
 
 def aioca_cleanup():
-    from aioca import purge_channel_caches, _catools
+    from aioca import purge_channel_caches, _catools, __version__
     # Unregister the aioca atexit handler as it conflicts with the one installed
     # by cothread. If we don't do this we get a seg fault. This is not a problem
     # in production as we won't mix aioca and cothread, but we do mix them in
     # the tests so need to do this.
-    atexit.unregister(_catools._Context._destroy_context)
+    # In aioca 1.8 the atexit function was changed to no longer cause this
+    # issue, when coupled with ensuring cothread is always imported first.
+    if Version(__version__) < Version("1.8"):
+        unregister_func = _catools._Context._destroy_context
+        atexit.unregister(unregister_func)
+
     # purge the channels before the event loop goes
     purge_channel_caches()