Port issue-1640.sli to Pytest

testsuite/pytests/sli2py_regressions/test_issue_1640.py

@@ -0,0 +1,68 @@
+# -*- coding: utf-8 -*-
+#
+# test_issue_1640.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 #1640 (GitHub).
+"""
+
+import numpy as np
+import pytest
+
+import nest
+
+
+@pytest.mark.skipif_missing_threads
+@pytest.mark.parametrize("num_threads", [2, 3, 4])
+@pytest.mark.parametrize("num_neurons", range(1, 11))
+def test_getconnections_with_pre_post_device_multithreaded(num_threads, num_neurons):
+    """
+    Multithreaded test of `GetConnections` with devices as source and target.
+
+    The test ensures that `GetConnections` does not return erroneous connections
+    when devices are connected as both source and target while using
+    multiple threads.
+    """
+
+    nest.ResetKernel()
+    nest.local_num_threads = num_threads
+
+    neurons = nest.Create("iaf_psc_alpha", num_neurons)
+    pgen = nest.Create("poisson_generator")
+    srec = nest.Create("spike_recorder")
+
+    # A poisson_generator is connected as source
+    nest.Connect(pgen, neurons)
+    # An additional device is connected as target
+    nest.Connect(neurons, srec)
+
+    # We only want the connections where the poisson_generator is source
+    conns = nest.GetConnections(source=pgen)
+
+    # Check that the poisson_generator is the source for all connections
+    expected_src_id = pgen.global_id
+    actual_src_ids = conns.get("source")
+    actual_src_ids = np.atleast_1d(actual_src_ids)  # Ensure source ids are iterable
+    assert np.all(actual_src_ids == expected_src_id)
+
+    # Check that number of connections is correct
+    expected_num_conns = num_neurons
+    actual_num_conns = actual_src_ids.size
+    assert actual_num_conns == expected_num_conns