Restore time_sync module on macOS

.github/workflows/test.yml

@@ -13,7 +13,6 @@ jobs:
         python-version: ["3.7", "3.8", "3.9", "3.10", "3.11"]
         include:
           - python-version: "3.10"
-            os: ubuntu-20.04
             coverage: "yes"
     steps:
       - uses: actions/checkout@v3

.pre-commit-config.yaml

@@ -25,7 +25,7 @@ repos:
     hooks:
       - id: flake8
   - repo: https://github.com/pre-commit/mirrors-mypy
-    rev: 'v0.990'
+    rev: 'v1.4.1'
     hooks:
       - id: mypy
         # Passing filenames to mypy can do odd things. See

src/aiokatcp/__init__.py

@@ -1,4 +1,4 @@
-# Copyright 2017, 2022 National Research Foundation (SARAO)
+# Copyright 2017, 2022, 2023 National Research Foundation (SARAO)
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are met:
@@ -37,8 +37,6 @@
     __version__ = _katversion.get_version(__path__[0])
 # END VERSION CHECK
 
-import sys
-
 from .client import (  # noqa: F401
     AbstractSensorWatcher,
     Client,
@@ -70,9 +68,7 @@
     SimpleAggregateSensor,
 )
 from .server import DeviceServer, RequestContext  # noqa: F401
-
-if sys.platform == "linux":
-    from .time_sync import ClockState, TimeSyncUpdater  # noqa: F401
+from .time_sync import ClockState, TimeSyncUpdater  # noqa: F401
 
 
 def minor_version():

src/aiokatcp/adjtimex.py

@@ -1,4 +1,4 @@
-# Copyright 2022 National Research Foundation (SARAO)
+# Copyright 2022, 2023 National Research Foundation (SARAO)
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are met:
@@ -25,10 +25,7 @@
 # OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-"""Python wrapper for the Linux-specific :func:`adjtimex` system call.
-
-Importing this module on a non-Linux system is likely to fail.
-"""
+"""Python wrapper for the Linux-specific :func:`adjtimex` system call."""
 
 import ctypes
 import os
@@ -85,13 +82,17 @@
 
 
 class Timeval(ctypes.Structure):
+    """See https://man7.org/linux/man-pages/man3/adjtime.3.html."""
+
     _fields_ = [
         ("tv_sec", ctypes.c_long),
         ("tv_usec", ctypes.c_long),
     ]
 
 
 class Timex(ctypes.Structure):
+    """See https://man7.org/linux/man-pages/man2/adjtimex.2.html."""
+
     _fields_ = [
         ("modes", ctypes.c_int),
         ("offset", ctypes.c_long),
@@ -117,18 +118,27 @@ class Timex(ctypes.Structure):
     ]
 
 
+def _no_adjtimex(timex: Timex) -> int:
+    raise NotImplementedError("System call 'adjtimex' is only available on Linux")
+
+
 def _errcheck(result, func, args):
     if result == -1:
         e = ctypes.get_errno()
         raise OSError(e, os.strerror(e))
     return result
 
 
-_libc = ctypes.CDLL("libc.so.6", use_errno=True)
-adjtimex = _libc.adjtimex
-adjtimex.argtypes = [ctypes.POINTER(Timex)]
-adjtimex.restype = ctypes.c_int
-adjtimex.errcheck = _errcheck  # type: ignore
+try:
+    _libc = ctypes.CDLL("libc.so.6", use_errno=True)
+except OSError:
+    adjtimex = _no_adjtimex
+else:
+    _real_adjtimex = _libc.adjtimex
+    _real_adjtimex.argtypes = [ctypes.POINTER(Timex)]
+    _real_adjtimex.restype = ctypes.c_int
+    _real_adjtimex.errcheck = _errcheck
+    adjtimex = _real_adjtimex
 
 
 def get_adjtimex() -> Tuple[int, Timex]:
@@ -142,6 +152,6 @@ def get_adjtimex() -> Tuple[int, Timex]:
         Clock information
     """
     timex = Timex()
-    timex.mode = 0
+    timex.modes = 0
     state = adjtimex(timex)
     return state, timex

src/aiokatcp/time_sync.py

@@ -1,4 +1,4 @@
-# Copyright 2022 National Research Foundation (SARAO)
+# Copyright 2022, 2023 National Research Foundation (SARAO)
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are met:
@@ -84,7 +84,13 @@ def __init__(self, sensor_map: Mapping[str, Sensor]) -> None:
 
     def update(self) -> None:
         """Update the sensors now."""
-        state, timex = adjtimex.get_adjtimex()
+        try:
+            state, timex = adjtimex.get_adjtimex()
+        except NotImplementedError:
+            for sensor in self.sensor_map.values():
+                sensor.set_value(sensor.value, Sensor.Status.INACTIVE)
+            return
+
         if timex.status & adjtimex.STA_NANO:
             scale = 1e-9
         else:

tests/test_time_sync.py

@@ -1,4 +1,4 @@
-# Copyright 2017, 2022 National Research Foundation (SARAO)
+# Copyright 2017, 2022, 2023 National Research Foundation (SARAO)
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are met:
@@ -31,9 +31,6 @@
 
 import pytest
 
-if sys.platform != "linux":
-    pytest.skip("skipping Linux-only tests based on adjtimex", allow_module_level=True)
-
 import aiokatcp.adjtimex
 from aiokatcp import Sensor, SensorSet
 from aiokatcp.time_sync import ClockState, TimeSyncUpdater
@@ -53,6 +50,14 @@ def updater(sensors: SensorSet) -> TimeSyncUpdater:
     return TimeSyncUpdater({sensor.name[4:]: sensor for sensor in sensors.values()})
 
 
+@pytest.fixture(params=[False, True])
+def pretend_no_adjtimex(mocker, request) -> bool:
+    """Optionally replace adjtimex with _no_adjtimex (i.e. pretend it is absent)."""
+    if request.param:
+        mocker.patch("aiokatcp.adjtimex.adjtimex", side_effect=aiokatcp.adjtimex._no_adjtimex)
+    return request.param
+
+
 @pytest.fixture(params=[False, True])
 def mock_adjtimex(mocker, request) -> None:
     """Replace get_adjtimex with a mock version with known values."""
@@ -62,22 +67,31 @@ def mock_adjtimex(mocker, request) -> None:
     timex.maxerror = 4567
     timex.time.tv_sec = 1234567890
     timex.time.tv_usec = 654321
+    # Check both microsecond and nanosecond versions of the timex struct
     if request.param:
         timex.status |= aiokatcp.adjtimex.STA_NANO
         timex.time.tv_usec *= 1000
     return_value = (aiokatcp.adjtimex.TIME_OK, timex)
     mocker.patch("aiokatcp.adjtimex.get_adjtimex", return_value=return_value)
 
 
-def test_smoke(sensors: SensorSet, updater: TimeSyncUpdater) -> None:
-    """Test with real adjtimex, to make sure it interacts cleanly with the kernel."""
+def test_smoke(sensors: SensorSet, updater: TimeSyncUpdater, pretend_no_adjtimex) -> None:
+    """Test with real adjtimex, to make sure it interacts cleanly with the kernel.
+
+    On non-Linux systems, check that the sensors are inactive instead. Also
+    pretend that we don't have adjtimex just to check both code paths on Linux.
+    """
     updater.update()
     assert isinstance(sensors["ntp.esterror"].value, float)
     assert isinstance(sensors["ntp.maxerror"].value, float)
     assert isinstance(sensors["ntp.state"].value, ClockState)
+    if not pretend_no_adjtimex and sys.platform == "linux":
+        expected_status = Sensor.Status.NOMINAL
+    else:
+        expected_status = Sensor.Status.INACTIVE
     for sensor in sensors.values():
         # Check that it actually got updated
-        assert sensor.status == Sensor.Status.NOMINAL
+        assert sensor.status == expected_status
 
 
 def test_bad_key(sensors) -> None: