From 790e3721647e1d481a9dba8e26c48df30fa9571c Mon Sep 17 00:00:00 2001
From: ppinchuk <ppinchuk@nrel.gov>
Date: Tue, 21 Nov 2023 16:11:36 -0700
Subject: [PATCH 1/3] Set mw to `None` if omitted from config file + test

---
 reV/generation/cli_gen.py |  1 +
 tests/test_gen_config.py  | 44 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 45 insertions(+)

diff --git a/reV/generation/cli_gen.py b/reV/generation/cli_gen.py
index 3882a4bdf..69c62bc49 100644
--- a/reV/generation/cli_gen.py
+++ b/reV/generation/cli_gen.py
@@ -43,6 +43,7 @@ def _preprocessor(config, job_name, log_directory, verbose,
         Updated config file.
     """
     init_cli_logging(job_name, log_directory, verbose)
+    config.get("execution_control", {}).setdefault("max_workers")
     analysis_years = format_analysis_years(analysis_years)
 
     config["resource_file"] = _parse_res_files(config["resource_file"],
diff --git a/tests/test_gen_config.py b/tests/test_gen_config.py
index 45e7098f0..d5e06da1c 100644
--- a/tests/test_gen_config.py
+++ b/tests/test_gen_config.py
@@ -17,6 +17,7 @@
 
 from reV.cli import main
 from reV.config.project_points import ProjectPoints
+from reV.generation.base import BaseGen
 from reV.generation.generation import Gen
 from reV import TESTDATADIR
 from reV.handlers.outputs import Outputs
@@ -181,6 +182,49 @@ def test_sam_config(tech):
                            gen_dict.out['cf_profile']), msg
 
 
+@pytest.mark.parametrize('expected_log_message',
+                         ["Running serial generation for",
+                          "Running parallel generation for"])
+def test_gen_mw_config_input(runner, clear_loggers, expected_log_message):
+    """Test max_workers input from gen config"""
+    with tempfile.TemporaryDirectory() as td:
+
+        run_dir = os.path.join(td, 'generation')
+        os.mkdir(run_dir)
+        project_points = os.path.join(TESTDATADIR, 'config', '..',
+                                      'config', "wtk_pp_2012_10.csv")
+        resource_file = os.path.join(TESTDATADIR, 'wtk/ri_100_wtk_{}.h5')
+        sam_files = {"wind0":
+                     os.path.join(TESTDATADIR,
+                                  "SAM/wind_gen_standard_losses_0.json")}
+
+        config = os.path.join(TESTDATADIR, 'config', 'local_wind.json')
+        config = safe_json_load(config)
+        if "parallel" in expected_log_message:
+            config["execution_control"].pop("max_workers")
+        else:
+            config["execution_control"]["max_workers"] = 1
+
+        config['project_points'] = project_points
+        config['resource_file'] = resource_file
+        config['sam_files'] = sam_files
+        config['log_directory'] = run_dir
+
+        config_path = os.path.join(run_dir, 'config.json')
+        with open(config_path, 'w') as f:
+            json.dump(config, f)
+
+        result = runner.invoke(main, ['generation', '-c', config_path])
+        msg = ('Failed with error {}'
+               .format(traceback.print_exception(*result.exc_info)))
+        assert result.exit_code == 0, msg
+
+        log_file = os.path.join(run_dir, 'generation_generation.log')
+        with open(log_file, "r") as fh:
+            assert expected_log_message in fh.read()
+        clear_loggers()
+
+
 def execute_pytest(capture='all', flags='-rapP'):
     """Execute module as pytest with detailed summary report.
 

From 65404331410d9aa8d1c5c8fcba282281a2a00bb8 Mon Sep 17 00:00:00 2001
From: ppinchuk <ppinchuk@nrel.gov>
Date: Tue, 21 Nov 2023 16:11:54 -0700
Subject: [PATCH 2/3] Updated documentation for new behavior

---
 reV/generation/generation.py | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/reV/generation/generation.py b/reV/generation/generation.py
index 42a8a0530..ef45e3f80 100644
--- a/reV/generation/generation.py
+++ b/reV/generation/generation.py
@@ -782,7 +782,10 @@ def run(self, out_fpath=None, max_workers=1, timeout=1800,
             module name and/or resource data year will get added to the
             output file name. By default, ``None``.
         max_workers : int, optional
-            Number of local workers to run on. By default, ``1``.
+            Number of local workers to run on. If ``None``, or if
+            running from the command line and omitting this argument
+            from your config file completely, this input is set to
+            ``os.cpu_count()``. Otherwise, the default is ``1``.
         timeout : int, optional
             Number of seconds to wait for parallel run iteration to
             complete before returning zeros. By default, ``1800``

From ec710b639d08351270d9b8b2519f200e57b77350 Mon Sep 17 00:00:00 2001
From: ppinchuk <ppinchuk@nrel.gov>
Date: Tue, 21 Nov 2023 16:15:14 -0700
Subject: [PATCH 3/3] Remove unused import

---
 tests/test_gen_config.py | 1 -
 1 file changed, 1 deletion(-)

diff --git a/tests/test_gen_config.py b/tests/test_gen_config.py
index d5e06da1c..364dd43c5 100644
--- a/tests/test_gen_config.py
+++ b/tests/test_gen_config.py
@@ -17,7 +17,6 @@
 
 from reV.cli import main
 from reV.config.project_points import ProjectPoints
-from reV.generation.base import BaseGen
 from reV.generation.generation import Gen
 from reV import TESTDATADIR
 from reV.handlers.outputs import Outputs