refactor give_sim_work_first for running on gen_workers if no points_to_evaluate. add test for mixed existing sample plus calling a gen

Author: jlnav

libensemble/alloc_funcs/give_sim_work_first.py

@@ -64,15 +64,19 @@ def give_sim_work_first(
     Work = {}
 
     points_to_evaluate = ~H["sim_started"] & ~H["cancel_requested"]
-    for wid in support.avail_worker_ids():
-        if np.any(points_to_evaluate):
+
+    if np.any(points_to_evaluate):
+        for wid in support.avail_worker_ids(gen_workers=False):
             sim_ids_to_send = support.points_by_priority(H, points_avail=points_to_evaluate, batch=batch_give)
             try:
                 Work[wid] = support.sim_work(wid, H, sim_specs["in"], sim_ids_to_send, persis_info.get(wid))
             except InsufficientFreeResources:
                 break
             points_to_evaluate[sim_ids_to_send] = False
-        else:
+            if not np.any(points_to_evaluate):
+                break
+    else:
+        for wid in support.avail_worker_ids(gen_workers=True):
             # Allow at most num_active_gens active generator instances
             if gen_count >= user.get("num_active_gens", gen_count + 1):
                 break

libensemble/tests/functionality_tests/test_evaluate_existing_plus_gen.py

@@ -0,0 +1,70 @@
+"""
+Test libEnsemble's capability to evalute existing points and then generate
+new samples via gen_on_manager.
+
+Execute via one of the following commands (e.g. 3 workers):
+   mpiexec -np 4 python test_evaluate_existing_sample.py
+   python test_evaluate_existing_sample.py --nworkers 3 --comms local
+   python test_evaluate_existing_sample.py --nworkers 3 --comms tcp
+
+The number of concurrent evaluations of the objective function will be 4-1=3.
+"""
+
+# Do not change these lines - they are parsed by run-tests.sh
+# TESTSUITE_COMMS: mpi local tcp
+# TESTSUITE_NPROCS: 2 4
+
+import numpy as np
+
+# Import libEnsemble items for this test
+from libensemble import Ensemble
+from libensemble.gen_funcs.sampling import latin_hypercube_sample as gen_f
+from libensemble.sim_funcs.six_hump_camel import six_hump_camel as sim_f
+from libensemble.specs import ExitCriteria, GenSpecs, SimSpecs
+from libensemble.tools import add_unique_random_streams
+
+
+def create_H0(persis_info, gen_specs, H0_size):
+    """Create an H0 for give_pregenerated_sim_work"""
+    # Manually creating H0
+    ub = gen_specs["user"]["ub"]
+    lb = gen_specs["user"]["lb"]
+    n = len(lb)
+    b = H0_size
+
+    H0 = np.zeros(b, dtype=[("x", float, 2), ("sim_id", int), ("sim_started", bool)])
+    H0["x"] = persis_info[0]["rand_stream"].uniform(lb, ub, (b, n))
+    H0["sim_id"] = range(b)
+    H0["sim_started"] = False
+    return H0
+
+
+# Main block is necessary only when using local comms with spawn start method (default on macOS and Windows).
+if __name__ == "__main__":
+
+    sampling = Ensemble(parse_args=True)
+    sampling.libE_specs.gen_on_manager = True
+    sampling.sim_specs = SimSpecs(sim_f=sim_f, inputs=["x"], out=[("f", float)])
+
+    gen_specs = {
+        "gen_f": gen_f,
+        "outputs": [("x", float, (2,))],
+        "user": {
+            "gen_batch_size": 50,
+            "lb": np.array([-3, -3]),
+            "ub": np.array([3, 3]),
+        },
+    }
+    sampling.gen_specs = GenSpecs(**gen_specs)
+    sampling.exit_criteria = ExitCriteria(sim_max=100)
+    sampling.persis_info = add_unique_random_streams({}, sampling.nworkers + 1)
+    sampling.H0 = create_H0(sampling.persis_info, gen_specs, 50)
+    sampling.run()
+
+    if sampling.is_manager:
+        assert len(sampling.H) == 2 * len(sampling.H0)
+        assert np.array_equal(sampling.H0["x"][:50], sampling.H["x"][:50])
+        assert np.all(sampling.H["sim_ended"])
+        assert np.all(sampling.H["gen_worker"] == 0)
+        print("\nlibEnsemble correctly didn't add anything to initial sample")
+        sampling.save_output(__file__)