Merge pull request #2810 from nicolossus/port_issue_2282

Port `issue-2282.sli` to Pytest

testsuite/pytests/sli2py_regressions/test_issue_2282.py

@@ -0,0 +1,78 @@
+# -*- coding: utf-8 -*-
+#
+# test_issue_2282.py
+#
+# This file is part of NEST.
+#
+# Copyright (C) 2004 The NEST Initiative
+#
+# NEST is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 2 of the License, or
+# (at your option) any later version.
+#
+# NEST is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with NEST.  If not, see <http://www.gnu.org/licenses/>.
+
+"""
+Regression test for Issue #2282 (GitHub).
+
+The test ensures that the `multimeter` cannot be connected to a
+`noise_generator` if NEST runs with multiple threads.
+"""
+
+import numpy as np
+import pytest
+
+import nest
+
+pytestmark = pytest.mark.skipif_missing_threads
+
+
+def simulator(num_threads):
+    """
+    Simulator for the tests.
+
+    The simulator sets up a system with a multimeter-recording from
+    `noise_generator`, which is allowed in single-threaded mode but
+    prohibited in multi-threaded mode.
+    """
+
+    nest.ResetKernel()
+    nest.local_num_threads = num_threads
+
+    nrns = nest.Create("iaf_psc_alpha", 3)
+    noise = nest.Create("noise_generator", 3, {"mean": 1000.0, "std": 1.0, "dt": 0.1})
+    mm = nest.Create("multimeter", {"record_from": ["I"], "interval": 0.1})
+
+    nest.Connect(noise, nrns, "one_to_one", {"delay": 0.1})
+    nest.Connect(mm, noise)
+
+    nest.Simulate(2.0)
+
+    recording = mm.events.get("I")
+
+    return recording
+
+
+def test_allowed_multimeter_record_noise_generator_singlethreaded():
+    """
+    Test that single-threaded mode works.
+
+    The recording returned by `simulator` should only contain non-zero values.
+    """
+
+    recording = simulator(num_threads=1)
+    assert np.all(recording > 0.0)
+
+
+def test_prohibited_multimeter_record_noise_generator_multithreaded():
+    """Test that an error is thrown in multi-threaded mode."""
+
+    with pytest.raises(nest.kernel.NESTError):
+        simulator(num_threads=2)