Skip lock acquisition in CrewTrainingHandler.load when file is missing (#5935)

Every agent kickoff calls _use_trained_data, which calls
CrewTrainingHandler(...).load(). Since #4827 wrapped load() in store_lock,
that means every kickoff acquires the cross-process (Redis-backed when
REDIS_URL is set) lock even on deployments that never train and have no
trained-agents file on disk.

Move the missing/empty-file short-circuit above store_lock so the lock is
only acquired when there is actually a file to read. save() and the real
read remain locked.

lib/crewai/src/crewai/utilities/file_handler.py

@@ -167,17 +167,12 @@ class PickleHandler:
         Returns:
             The data loaded from the file.
         """
-        with store_lock(f"file:{os.path.realpath(self.file_path)}"):
-            if (
-                not os.path.exists(self.file_path)
-                or os.path.getsize(self.file_path) == 0
-            ):
-                return {}
+        if not os.path.exists(self.file_path):
+            return {}
 
-            with open(self.file_path, "rb") as file:
-                try:
+        with store_lock(f"file:{os.path.realpath(self.file_path)}"):
+            try:
+                with open(self.file_path, "rb") as file:
                     return pickle.load(file)  # noqa: S301
-                except EOFError:
-                    return {}
-                except Exception:
-                    raise
+            except (FileNotFoundError, EOFError):
+                return {}

lib/crewai/tests/agents/test_agent.py

@@ -1083,6 +1083,21 @@ def test_agent_use_trained_data_honors_env_var(crew_training_handler, monkeypatc
     )
 
 
+def test_agent_use_trained_data_skips_load_when_file_missing(tmp_path, monkeypatch):
+    monkeypatch.setenv(
+        "CREWAI_TRAINED_AGENTS_FILE", str(tmp_path / "does_not_exist.pkl")
+    )
+    agent = Agent(role="researcher", goal="test goal", backstory="test backstory")
+
+    with patch(
+        "crewai.utilities.file_handler.store_lock",
+        side_effect=AssertionError("kickoff acquired lock with no trained-agents file"),
+    ):
+        result = agent._use_trained_data(task_prompt="What is 1 + 1?")
+
+    assert result == "What is 1 + 1?"
+
+
 def test_agent_max_retry_limit():
     agent = Agent(
         role="test role",

lib/crewai/tests/utilities/test_training_handler.py

@@ -1,6 +1,7 @@
 import os
 import tempfile
 import unittest
+from unittest.mock import patch
 
 from crewai.utilities.training_handler import CrewTrainingHandler
 
@@ -53,3 +54,23 @@ class InternalCrewTrainingHandler(unittest.TestCase):
         # Assert that the new agent and data are appended correctly
         data = self.handler.load()
         assert data[agent_id][train_iteration] == new_data
+
+    def test_load_missing_file_does_not_acquire_lock(self):
+        handler = CrewTrainingHandler(self.temp_file.name + ".missing")
+
+        with patch(
+            "crewai.utilities.file_handler.store_lock",
+            side_effect=AssertionError("load() acquired lock for missing file"),
+        ):
+            assert handler.load() == {}
+
+    def test_load_acquires_lock_for_zero_size_file(self):
+        # Empty file mimics a concurrent save() mid-truncation (open "wb").
+        assert os.path.getsize(self.temp_file.name) == 0
+
+        with patch(
+            "crewai.utilities.file_handler.store_lock",
+            side_effect=AssertionError("load() short-circuited on size 0"),
+        ):
+            with self.assertRaises(AssertionError):
+                self.handler.load()