Run unit tests in parallel. (#45812)

(cherry picked from commit abe8e4c9e8)

test/runner/lib/executor.py

@@ -1156,6 +1156,7 @@ def command_units(args):
             'pytest',
             '--boxed',
             '-r', 'a',
+            '-n', 'auto',
             '--color',
             'yes' if args.color else 'no',
             '--junit-xml',

test/units/conftest.py

@@ -24,8 +24,16 @@ def pytest_configure():
             coverage_instances.append(obj)
 
     if not coverage_instances:
+        coverage_config = os.environ.get('_ANSIBLE_COVERAGE_CONFIG')
+
+        if not coverage_config:
             return
 
+        cov = coverage.Coverage(config_file=coverage_config)
+        coverage_instances.append(cov)
+    else:
+        cov = None
+
     os_exit = os._exit
 
     def coverage_exit(*args, **kwargs):
@@ -36,3 +44,6 @@ def pytest_configure():
         os_exit(*args, **kwargs)
 
     os._exit = coverage_exit
+
+    if cov:
+        cov.start()