From 860f7eb1fc654fc7ba5a03204fd6ac70f01fece4 Mon Sep 17 00:00:00 2001
From: Tim Pillinger <26465611+wxtim@users.noreply.github.com>
Date: Wed, 25 Oct 2023 15:26:12 +0100
Subject: [PATCH] Stop task proxy clock trigger time being cached to prevent
 all clock triggers being the same.

---
 cylc/flow/task_proxy.py   | 29 ++++++++++++++++-------------
 cylc/flow/xtrigger_mgr.py |  1 +
 2 files changed, 17 insertions(+), 13 deletions(-)

diff --git a/cylc/flow/task_proxy.py b/cylc/flow/task_proxy.py
index 271049126fd..0e0317aac9a 100644
--- a/cylc/flow/task_proxy.py
+++ b/cylc/flow/task_proxy.py
@@ -355,25 +355,28 @@ def get_point_as_seconds(self):
                 self.point_as_seconds += utc_offset_in_seconds
         return self.point_as_seconds
 
-    def get_clock_trigger_time(self, offset_str):
-        """Compute, cache, and return trigger time relative to cycle point.
+    @staticmethod
+    def get_clock_trigger_time(
+        point: 'PointBase', offset_str: Optional[str] = None
+    ) -> int:
+        """Compute and return trigger time relative to cycle point.
 
         Args:
-            offset_str: ISO8601Interval string, e.g. "PT2M".
-                        Can be None for zero offset.
+            point: String representing itask string.
+            offset_str:
+                ISO8601Interval string, e.g. "PT2M".
+                Can be None for zero offset.
         Returns:
             Absolute trigger time in seconds since Unix epoch.
 
         """
-        if self.clock_trigger_time is None:
-            if offset_str is None:
-                trigger_time = self.point
-            else:
-                trigger_time = self.point + ISO8601Interval(offset_str)
-            self.clock_trigger_time = int(
-                point_parse(str(trigger_time)).seconds_since_unix_epoch
-            )
-        return self.clock_trigger_time
+        if offset_str is None:
+            trigger_time = point
+        else:
+            trigger_time = point + ISO8601Interval(offset_str)
+
+        return int(
+            point_parse(str(trigger_time)).seconds_since_unix_epoch)
 
     def get_try_num(self):
         """Return the number of automatic tries (try number)."""
diff --git a/cylc/flow/xtrigger_mgr.py b/cylc/flow/xtrigger_mgr.py
index 4512d97b7c8..35b8e88b36c 100644
--- a/cylc/flow/xtrigger_mgr.py
+++ b/cylc/flow/xtrigger_mgr.py
@@ -388,6 +388,7 @@ def get_xtrig_ctx(self, itask: TaskProxy, label: str) -> SubFuncContext:
                 # External (clock xtrigger): convert offset to trigger_time.
                 # Datetime cycling only.
                 kwargs["trigger_time"] = itask.get_clock_trigger_time(
+                    itask.point,
                     ctx.func_kwargs["offset"]
                 )
             else: