Parallel test configuration

test/conftest.py

@@ -1,3 +1,4 @@
+from subprocess import check_call
 
 
 def pytest_runtest_teardown(item, nextitem):
@@ -12,3 +13,84 @@ def pytest_runtest_teardown(item, nextitem):
     Kernel._cache.clear()
     TSFCKernel._cache.clear()
     JITModule._cache.clear()
+
+
+def parallel(item):
+    """
+    Run a test in parallel.
+
+    NOTE: Copied from firedrake/src/firedrake/tests/conftest.py
+
+    :arg item: The test item to run.
+    """
+    from mpi4py import MPI
+    if MPI.COMM_WORLD.size > 1:
+        raise RuntimeError("Parallel test can't be run within parallel environment")
+    marker = item.get_closest_marker("parallel")
+    if marker is None:
+        raise RuntimeError("Parallel test doesn't have parallel marker")
+    nprocs = marker.kwargs.get("nprocs", 3)
+    if nprocs < 2:
+        raise RuntimeError("Need at least two processes to run parallel test")
+
+    # Only spew tracebacks on rank 0.
+    # Run xfailing tests to ensure that errors are reported to calling process
+    call = [
+        "mpiexec", "-n", "1", "python", "-m", "pytest", "--runxfail", "-s", "-q",
+        "%s::%s" % (item.fspath, item.name)
+    ]
+    call.extend([
+        ":", "-n", "%d" % (nprocs - 1), "python", "-m", "pytest", "--runxfail", "--tb=no", "-q",
+        "%s::%s" % (item.fspath, item.name)
+    ])
+    check_call(call)
+
+
+def pytest_configure(config):
+    """
+    Register an additional marker.
+
+    NOTE: Copied from firedrake/src/firedrake/tests/conftest.py
+    """
+    config.addinivalue_line(
+        "markers",
+        "parallel(nprocs): mark test to run in parallel on nprocs processors")
+
+
+def pytest_runtest_setup(item):
+    """
+    Special setup for parallel tests.
+
+    NOTE: Copied from firedrake/src/firedrake/tests/conftest.py
+    """
+    if item.get_closest_marker("parallel"):
+        from mpi4py import MPI
+        if MPI.COMM_WORLD.size > 1:
+            # Turn on source hash checking
+            from firedrake import parameters
+            from functools import partial
+
+            def _reset(check):
+                parameters["pyop2_options"]["check_src_hashes"] = check
+
+            # Reset to current value when test is cleaned up
+            item.addfinalizer(partial(_reset,
+                                      parameters["pyop2_options"]["check_src_hashes"]))
+
+            parameters["pyop2_options"]["check_src_hashes"] = True
+        else:
+            # Blow away function arg in "master" process, to ensure
+            # this test isn't run on only one process.
+            item.obj = lambda *args, **kwargs: True
+
+
+def pytest_runtest_call(item):
+    """
+    Special call for parallel tests.
+
+    NOTE: Copied from firedrake/src/firedrake/tests/conftest.py
+    """
+    from mpi4py import MPI
+    if item.get_closest_marker("parallel") and MPI.COMM_WORLD.size == 1:
+        # Spawn parallel processes to run test
+        parallel(item)