Address @promano comments

docs/source/capi/index.rst

@@ -271,7 +271,7 @@ Functions
    Get number of batches to simulate
 
    :param int* n_batches: Number of batches to simulate
-   :param int* get_max_batches: Whether to return `n_batches` or `n_max_batches` (only relevant when triggers are used)
+   :param bool get_max_batches: Whether to return `n_batches` or `n_max_batches` (only relevant when triggers are used)
    :return: Return status (negative if an error occurred)
    :rtype: int
 

openmc/lib/settings.py

@@ -66,14 +66,14 @@ class _Settings:
         _dll.openmc_set_seed(seed)
 
     def set_batches(self, n_batches, set_max_batches=True, add_sp_batch=True):
-        """Set n_batches
+        """Set number of batches or maximum number of batches
 
         Parameters
         ----------
         n_batches : int
             Number of batches to simulate
-        set_max_batches : int
-            Whether to set maximum number of batches. If true, the value of
+        set_max_batches : bool
+            Whether to set maximum number of batches. If True, the value of
             `n_max_batches` is overridden, otherwise the value of `n_batches`
             is overridden. Only has an effect when triggers are used
         add_sp_batch : bool

src/settings.cpp

@@ -849,13 +849,13 @@ openmc_set_n_batches(int32_t n_batches, bool set_max_batches,
     // Set n_batches and n_max_batches to same value
     settings::n_batches = n_batches;
     settings::n_max_batches = n_batches;
-  }
-  else {
+  } else {
     // Set n_batches and n_max_batches based on value of set_max_batches
-    if (set_max_batches)
+    if (set_max_batches) {
       settings::n_max_batches = n_batches;
-    else
+    } else {
       settings::n_batches = n_batches;
+    }
   }
 
   // Update size of k_generation and entropy
@@ -874,10 +874,7 @@ openmc_set_n_batches(int32_t n_batches, bool set_max_batches,
 extern "C" int
 openmc_get_n_batches(int* n_batches, bool get_max_batches)
 {
-  if (get_max_batches)
-    *n_batches = settings::n_max_batches;
-  else
-    *n_batches = settings::n_batches;
+  *n_batches = get_max_batches ? settings::n_max_batches : settings::n_batches;
 
   return 0;
 }

tests/unit_tests/test_lib.py

@@ -49,6 +49,37 @@ def pincell_model():
         yield
 
 
+@pytest.fixture(scope='module')
+def uo2_trigger_model():
+    """Set up a simple UO2 model with k-eff trigger"""
+    model = openmc.model.Model()
+    m = openmc.Material(name='UO2')
+    m.add_nuclide('U235', 1.0)
+    m.add_nuclide('O16', 2.0)
+    m.set_density('g/cm3', 10.0)
+    model.materials.append(m)
+
+    cyl = openmc.ZCylinder(r=1.0, boundary_type='vacuum')
+    c = openmc.Cell(fill=m, region=-cyl)
+    model.geometry.root_universe = openmc.Universe(cells=[c])
+
+    model.settings.batches = 10
+    model.settings.inactive = 5
+    model.settings.particles = 100
+    model.settings.source = openmc.Source(space=openmc.stats.Box(
+        [-0.5, -0.5, -1], [0.5, 0.5, 1], only_fissionable=True))
+    model.settings.verbosity = 1
+    model.settings.keff_trigger = {'type': 'std_dev', 'threshold': 0.001}
+    model.settings.trigger_active = True
+    model.settings.trigger_max_batches = 10
+    model.settings.trigger_batch_interval = 1
+
+    # Write XML files in tmpdir
+    with cdtemp():
+        model.export_to_xml()
+        yield
+
+
 @pytest.fixture(scope='module')
 def lib_init(pincell_model, mpi_intracomm):
     openmc.lib.init(intracomm=mpi_intracomm)
@@ -550,17 +581,7 @@ def test_global_bounding_box(lib_init):
     assert tuple(urc) == expected_urc
 
 
-def test_trigger_set_n_batches(lib_run, mpi_intracomm):
-    openmc.reset_auto_ids()
-    pincell = openmc.examples.pwr_pin_cell()
-    pincell.settings.verbosity = 1
-    pincell.settings.keff_trigger = {'type': 'std_dev', 'threshold': 0.01}
-    pincell.settings.trigger_active = True
-    pincell.settings.trigger_max_batches = 10
-    pincell.settings.trigger_batch_interval = 1
-
-    pincell.export_to_xml()
-    openmc.lib.hard_reset()
+def test_trigger_set_n_batches(uo2_trigger_model, mpi_intracomm):
     openmc.lib.finalize()
     openmc.lib.init(intracomm=mpi_intracomm)
     openmc.lib.simulation_init()