refactor(ddg): use threadpool with active polling for state

csaxs_bec/device_configs/endstation.yaml

@@ -32,7 +32,7 @@ mcs:
 
 ids_cam:
   description: IDS camera for live image acquisition
-  deviceClass: csaxs_bec.devices.ids_cameras.ids_camera_new.IDSCamera
+  deviceClass: csaxs_bec.devices.ids_cameras.IDSCamera
   deviceConfig:
     camera_id: 201
     bits_per_pixel: 24

csaxs_bec/devices/epics/delay_generator_csaxs/ddg_1.py

@@ -31,11 +31,14 @@ DELAY CHANNELS:
 
 from __future__ import annotations
 
+import threading
 import time
+from concurrent.futures import Future, ThreadPoolExecutor
 from typing import TYPE_CHECKING
 
 from bec_lib.logger import bec_logger
-from ophyd import DeviceStatus, StatusBase
+from ophyd import Component as Cpt
+from ophyd import DeviceStatus, Signal, StatusBase
 from ophyd_devices import CompareStatus, TransitionStatus
 from ophyd_devices.interfaces.base_classes.psi_device_base import PSIDeviceBase
 
@@ -48,6 +51,7 @@ from csaxs_bec.devices.epics.delay_generator_csaxs.delay_generator_csaxs import
     AllChannelNames,
     ChannelConfig,
     DelayGeneratorCSAXS,
+    StatusBitsCompareStatus,
 )
 from csaxs_bec.devices.epics.mcs_card.mcs_card_csaxs import ACQUIRING, READYTOREAD
 
@@ -110,6 +114,9 @@ class DDG1(PSIDeviceBase, DelayGeneratorCSAXS):
             name=name, prefix=prefix, scan_info=scan_info, device_manager=device_manager, **kwargs
         )
         self.device_manager = device_manager
+        self._threadpool = ThreadPoolExecutor(max_workers=1)
+        self._status_thread_event = threading.Event()
+        self._status_future = None  # Future for the status job
 
     # pylint: disable=attribute-defined-outside-init
     def on_connected(self) -> None:
@@ -124,7 +131,7 @@ class DDG1(PSIDeviceBase, DelayGeneratorCSAXS):
         self.set_trigger(DEFAULT_TRIGGER_SOURCE)
         self.set_references_for_channels(DEFAULT_REFERENCES)
         # Set proc status to passively update with 5Hz (0.2s)
-        self.state.proc_status_mode.put(PROC_EVENT_MODE.FREQ_5HZ)
+        self.state.proc_status_mode.put(PROC_EVENT_MODE.EVENT)
 
     def on_stage(self) -> DeviceStatus | StatusBase | None:
         """
@@ -134,7 +141,8 @@ class DDG1(PSIDeviceBase, DelayGeneratorCSAXS):
 
         This DDG is always not in burst mode.
         """
-        self.burst_disable()
+        exp_time = self.scan_info.msg.scan_parameters["exp_time"]
+        self.burst_enable(1, 0, exp_time)
         exp_time = self.scan_info.msg.scan_parameters["exp_time"]
         frames_per_trigger = self.scan_info.msg.scan_parameters["frames_per_trigger"]
         # Trigger DDG2
@@ -151,73 +159,96 @@ class DDG1(PSIDeviceBase, DelayGeneratorCSAXS):
         # e has refernce to d, f has reference to e
         self.set_delay_pairs(channel="ef", delay=0, width=1e-6)
 
+    def _prepare_mcs_on_trigger(self, mcs: MCSCardCSAXS) -> None:
+        """Prepare the MCS card for the next trigger.
+        This method holds the logic to ensure that the MCS card is ready to read.
+        It's logic is coupled to the MCS card implementation and the DDG1 trigger logic.
+        """
+        status_ready_read = CompareStatus(mcs.ready_to_read, READYTOREAD.DONE)
+        mcs.stop_all.put(1)
+        status_acquiring = TransitionStatus(mcs.acquiring, [ACQUIRING.DONE, ACQUIRING.ACQUIRING])
+        self.cancel_on_stop(status_ready_read)
+        self.cancel_on_stop(status_acquiring)
+        status_ready_read.wait(10)
+
+        mcs.ready_to_read.put(READYTOREAD.PROCESSING)
+        mcs.erase_start.put(1)
+        status_acquiring.wait(timeout=10)  # Allow 10 seconds in case communication is slow
+
+    def _reset_status_event_future(self) -> None:
+        """Reset the status future and thread event."""
+        if self._status_future and not self._status_future.done():
+            self._status_thread_event.set()
+            self._status_future.result(timeout=10)  # Allow 10 seconds for communication to finish
+
+        # Reset to known state
+        self._status_thread_event.clear()
+        self.state.proc_status.put(1, use_complete=True)
+
+    def _prepare_trigger_status_event(self, timeout: float | None = None) -> DeviceStatus:
+        """Prepare the trigger status event for the DDG1, and trigger the de"""
+        if timeout is None:
+            # Default timeout of 5 seconds + exposure time * frames_per_trigger
+            timeout = 5 + self.scan_info.msg.scan_parameters.get(
+                "exp_time", 0.1
+            ) * self.scan_info.msg.scan_parameters.get("frames_per_trigger", 1)
+
+        # Callback to cancel the status if the device is stopped
+        def cancel_cb(status: CompareStatus) -> None:
+            """Callback to cancel the status if the device is stopped."""
+            self._status_thread_event.set()
+
+        status = StatusBitsCompareStatus(
+            self.state.event_status, STATUSBITS.END_OF_BURST, timeout=timeout, run=False
+        )
+        status.add_callback(cancel_cb)
+        self.cancel_on_stop(status)
+
+        # Callback to poll events, this gets executed in a separate thread by the threadpool
+        def _status_job():
+            """Callback to poll event status an update the status_event signal."""
+            while not self._status_thread_event.is_set():
+                self.state.proc_status.put(1, use_complete=True)
+                time.sleep(0.02)  # 20ms delay for processing
+                self.state.event_status.get(use_monitor=False)
+                time.sleep(0.02)  # 20ms delay for processing
+
+        # Submit the status job to the threadpool
+        self._status_future = self._threadpool.submit(_status_job)
+        return status
+
     def on_trigger(self) -> DeviceStatus | StatusBase | None:
         """Note, we need to add a delay to the StatusBits callback on the event_status.
         If we don't then subsequent triggers may reach the DDG too early, and will be ignored. To
         avoid this, we've added the option to specify a delay via add_delay, default here is 50ms.
         """
-        status = CompareStatus(self.state.event_status, STATUSBITS.NONE)
-        self.cancel_on_stop(status)
+        # Make sure to reset the status future and thread event
+        self._reset_status_event_future()
+
+        # Prepare the MCS card for the next software trigger
         mcs = self.device_manager.devices.get("mcs", None)
         if mcs is None:
             logger.info("Did not find mcs card with name 'mcs' in current session")
         else:
-            mcs: MCSCardCSAXS
-            status_ready_read = CompareStatus(mcs.ready_to_read, READYTOREAD.DONE)
-            mcs.stop_all.put(1)
-            status_acquiring = TransitionStatus(
-                mcs.acquiring, [ACQUIRING.DONE, ACQUIRING.ACQUIRING]
-            )
-            self.cancel_on_stop(status_ready_read)
-            self.cancel_on_stop(status_acquiring)
-            status_ready_read.wait(10)
-
-            mcs.ready_to_read.put(READYTOREAD.PROCESSING)
-            mcs.erase_start.put(1)
-            status_acquiring.wait(
-                timeout=10
-            )  # 2 s wait for mcs card to start should be more than enough..
-        status.wait(timeout=10)
-        # Default timeout of 5 seconds + exposure time * frames_per_trigger
-        timeout = 5 + self.scan_info.msg.scan_parameters.get(
-            "exp_time", 0.1
-        ) * self.scan_info.msg.scan_parameters.get("frames_per_trigger", 1)
-        status = CompareStatus(self.state.event_status, STATUSBITS.END_OF_DELAY, timeout=timeout)
-        self.cancel_on_stop(status)
+            self._prepare_mcs_on_trigger(mcs)
+        # Prepare status to wait for the end of burst
+        status = self._prepare_trigger_status_event()
+        # Trigger the DDG1
         self.trigger_shot.put(1, use_complete=True)
         return status
 
-    def wait_for_status(
-        self, status: DeviceStatus, bit_event: STATUSBITS, timeout: float = 2
-    ) -> None:
-        """Wait for a event status bit to be set.
-
-        Args:
-            status (DeviceStatus): The status object to update.
-            bit_event (STATUSBITS): The event status bit to wait for.
-            timeout (float): Maximum time to wait for the event status bit to be set.
-        """
-        current_time = time.time()
-        while not status.done:
-            self.state.proc_status.put(1, use_complete=True)
-            event_status = self.state.event_status.get()
-            if (STATUSBITS(event_status) & bit_event) == bit_event:
-                status.set_finished()
-            if time.time() - current_time > timeout:
-                status.set_exception(
-                    TimeoutError(
-                        f"Timeout waiting for status of device {self.name} for event_status {bit_event}"
-                    )
-                )
-                break
-            time.sleep(0.1)
-        time.sleep(0.05)  # Give time for the IOC to be ready again
-        return status
-
     def on_stop(self) -> None:
         """Stop the delay generator by setting the burst mode to 0"""
         self.stop_ddg()
 
+    def on_destroy(self):
+        """Clean up resources when the device is destroyed."""
+        self._status_thread_event.set()
+        if hasattr(self, "_threadpool") and self._threadpool is not None:
+            self._threadpool.shutdown(wait=False)
+            self._threadpool = None
+        super().on_destroy()
+
 
 if __name__ == "__main__":
     ddg = DDG1(name="ddg1", prefix="X12SA-CPCL-DDG1:")

csaxs_bec/devices/epics/delay_generator_csaxs/delay_generator_csaxs.py

@@ -402,7 +402,6 @@ class DelayGeneratorEventStatus(Device):
         EpicsSignal,
         "EventStatusLI.PROC",
         name="proc_status",
-        auto_monitor=True,
         kind=Kind.omitted,
         doc="Poll and flush the latest event status register entry from the HW to the event_status signal",
     )

tests/tests_devices/test_delay_generator_csaxs.py

@@ -191,7 +191,10 @@ def test_ddg1_stage(mock_ddg1):
 
     mock_ddg1.stage()
 
-    assert np.isclose(mock_ddg1.burst_mode.get(), 0)  # Burst mode is disabled
+    assert np.isclose(mock_ddg1.burst_mode.get(), 1)  # burst mode is enabled
+    assert np.isclose(mock_ddg1.burst_delay.get(), 0)
+    assert np.isclose(mock_ddg1.burst_period.get(), exp_time)
+
     # Trigger DDG2 through EXT/EN
 
     assert np.isclose(mock_ddg1.ab.delay.get(), 2e-3)
@@ -218,7 +221,7 @@ def test_ddg1_trigger(mock_ddg1):
         assert status.done is False
         assert status.success is False
         assert mock_ddg1.trigger_shot.get() == 1
-        mock_ddg1.state.event_status._read_pv.mock_data = STATUSBITS.END_OF_DELAY.value
+        mock_ddg1.state.event_status._read_pv.mock_data = STATUSBITS.END_OF_BURST.value
         status.wait(timeout=1)  # Wait for the status to be done
         assert status.done is True
         assert status.success is True