Add algorithm to programmatically enable/disable perf

GaudiExamples/tests/pytest/test_perf_profile.py

+#####################################################################################
+# (c) Copyright 2022-2023 CERN for the benefit of the LHCb and ATLAS collaborations #
+#                                                                                   #
+# This software is distributed under the terms of the Apache version 2 licence,     #
+# copied verbatim in the file "LICENSE".                                            #
+#                                                                                   #
+# In applying this licence, CERN does not waive the privileges and immunities       #
+# granted to it by virtue of its status as an Intergovernmental Organization        #
+# or submit itself to any jurisdiction.                                             #
+#####################################################################################
+import os
+from threading import Thread
+
+from GaudiTests import run_gaudi
+
+
+def config():
+    from Configurables import ApplicationMgr, PerfProfile
+
+    prof = PerfProfile(
+        FIFOPath="control.fifo",
+        StartFromEventN=3,
+        StopAtEventN=8,
+    )
+    ApplicationMgr(
+        EvtSel="NONE",
+        EvtMax=10,
+        TopAlg=[prof],
+    )
+
+
+def test(tmp_path):
+    """Emulate perf record --control"""
+    fifo = tmp_path / "control.fifo"
+    fifo_lines = []
+    os.mkfifo(fifo)
+
+    def reader():
+        # open blocks until FIFO is opened for writing by PerfProfile::initialize(), so run it in a thread
+        with open(fifo) as f:
+            for line in f:
+                fifo_lines.append(line)
+
+    t = Thread(target=reader)
+    t.start()
+
+    run_gaudi(f"{__file__}:config", check=True, cwd=tmp_path)
+
+    t.join()
+
+    assert fifo_lines == ["enable\n", "disable\n"]