feature 1320 OMP_NUM_THREADS

docs/Users_Guide/glossary.rst

@@ -8693,3 +8693,13 @@ METplus Configuration Glossary
      :term:`VALID_TIME_FMT` or they will be skipped.
 
      | *Used by:* All
+
+   OMP_NUM_THREADS
+     Sets environment variable of the same name that determines the number
+     of threads to use in the MET executables. Defaults to 1 thread.
+     If the environment variable of the same name is already set in the
+     user's environment, then that value will be used instead of the value
+     set in the METplus configuration. A warning will be output if this is the
+     case and the values differ between them.
+
+     | *Used by:* All

docs/Users_Guide/systemconfiguration.rst

@@ -205,6 +205,13 @@ By default this is a directory called **stage** inside the
 
 This value is rarely changed, but it can be if desired.
 
+OMP_NUM_THREADS
+^^^^^^^^^^^^^^^
+
+If the MET executables were installed with threading support, then the number
+of threads used by the tools can be configured with this variable. See
+the glossary entry for :term:`OMP_NUM_THREADS` for more information.
+
 CONVERT
 ^^^^^^^
 

metplus/util/met_util.py

@@ -88,6 +88,11 @@ def pre_run_setup(config_inputs):
     # handle dir to write temporary files
     handle_tmp_dir(config)
 
+    # handle OMP_NUM_THREADS environment variable
+    handle_env_var_config(config,
+                          env_var_name='OMP_NUM_THREADS',
+                          config_name='OMP_NUM_THREADS')
+
     config.env = os.environ.copy()
 
     return config
@@ -230,19 +235,7 @@ def handle_tmp_dir(config):
      get config temp dir using getdir_nocheck to bypass check for /path/to
      this is done so the user can set env MET_TMP_DIR instead of config TMP_DIR
      and config TMP_DIR will be set automatically"""
-    met_tmp_dir = os.environ.get('MET_TMP_DIR', '')
-    conf_tmp_dir = config.getdir_nocheck('TMP_DIR', '')
-
-    # if env MET_TMP_DIR is set
-    if met_tmp_dir:
-        # override config TMP_DIR to env MET_TMP_DIR value
-        config.set('config', 'TMP_DIR', met_tmp_dir)
-
-        # if config TMP_DIR differed from env MET_TMP_DIR, warn
-        if conf_tmp_dir != met_tmp_dir:
-            msg = 'TMP_DIR in config will be overridden by the ' +\
-                'environment variable MET_TMP_DIR ({})'.format(met_tmp_dir)
-            config.logger.warning(msg)
+    handle_env_var_config(config, 'MET_TMP_DIR', 'TMP_DIR')
 
     # create temp dir if it doesn't exist already
     # this will fail if TMP_DIR is not set correctly and
@@ -251,6 +244,30 @@ def handle_tmp_dir(config):
     if not os.path.exists(tmp_dir):
         os.makedirs(tmp_dir)
 
+def handle_env_var_config(config, env_var_name, config_name):
+    """! If environment variable is set, use that value
+     for the config variable and warn if the previous config value differs
+
+     @param config METplusConfig object to read
+     @param env_var_name name of environment variable to read
+     @param config_name name of METplus config variable to check
+    """
+    env_var_value = os.environ.get(env_var_name, '')
+    config_value = config.getdir_nocheck(config_name, '')
+
+    # do nothing if environment variable is not set
+    if not env_var_value:
+        return
+
+    # override config config variable to environment variable value
+    config.set('config', config_name, env_var_value)
+
+    # if config config value differed from environment variable value, warn
+    if config_value != env_var_value:
+        config.logger.warning(f'Config variable {config_name} ({config_value}) '
+                              'will be overridden by the environment variable '
+                              f'{env_var_name} ({env_var_value})')
+
 def get_skip_times(config, wrapper_name=None):
     """! Read SKIP_TIMES config variable and populate dictionary of times that should be skipped.
          SKIP_TIMES should be in the format: "%m:begin_end_incr(3,11,1)", "%d:30,31", "%Y%m%d:20201031"

metplus/wrappers/command_builder.py

@@ -70,6 +70,7 @@ def __init__(self, config, instance=None, config_overrides=None):
         # list of environment variables to set before running command
         self.env_var_keys = [
             'MET_TMP_DIR',
+            'OMP_NUM_THREADS',
         ]
         if hasattr(self, 'WRAPPER_ENV_VAR_KEYS'):
             self.env_var_keys.extend(self.WRAPPER_ENV_VAR_KEYS)
@@ -117,6 +118,11 @@ def __init__(self, config, instance=None, config_overrides=None):
         # where the MET tools write temporary files
         self.env_var_dict['MET_TMP_DIR'] = self.config.getdir('TMP_DIR')
 
+        # set OMP_NUM_THREADS environment variable
+        self.env_var_dict['OMP_NUM_THREADS'] = (
+            self.config.getstr('config', 'OMP_NUM_THREADS')
+        )
+
         self.check_for_externals()
 
         self.cmdrunner = CommandRunner(

parm/metplus_config/defaults.conf

@@ -57,13 +57,18 @@ GFDL_TRACKER_EXEC = /path/to/standalone_gfdl-vortextracker_v3.9a/trk_exec
 
 ###############################################################################
 # Runtime Configuration                                                       #
+#   * OMP_NUM_THREADS sets an environment variable of the same name that      #
+#     determines the number of threads to use in the MET executables. If the  #
+#     environment variable is already set in the user's environment, then     #
+#     that value will be used instead of the value set in this file.          #
 ###############################################################################
 
 
 LOOP_ORDER = processes
 
 PROCESS_LIST = Usage
 
+OMP_NUM_THREADS = 1
 
 ###############################################################################
 # Log File Information (Where to write logs files)                            #