mpm: avoid importing from rpc_server when importing usrp_mpm

Importing from usrp_mpm.rpc_server imports a lot of dependencies which are
unnecessary if the rpc_server functionality is not actually needed.

Move the decorator functions to a new file rpc_utils.py and import only
from this file inside periph_manager.

usrp_hwd.py needs additional dependencies which are specifically imported:
- usrp_mpm.rpc_server.spawn_rpc_process
- usrp_mpm.discovery.spawn_discovery_process

mpm/python/usrp_hwd.py

@@ -13,6 +13,8 @@ import time
 import argparse
 from gevent import signal
 import usrp_mpm as mpm
+import usrp_mpm.rpc_server
+import usrp_mpm.discovery
 from usrp_mpm.mpmtypes import SharedState
 from usrp_mpm.sys_utils import watchdog
 
@@ -162,14 +164,14 @@ def spawn_processes(log, args):
     shared = SharedState()
     log.info("Spawning RPC process...")
     _PROCESSES.append(
-        mpm.spawn_rpc_process(
+        mpm.rpc_server.spawn_rpc_process(
             shared, mpm.mpmtypes.MPM_RPC_PORT, args.default_args))
     log.debug("RPC process has PID: %d", _PROCESSES[-1].pid)
     if watchdog.has_watchdog():
         watchdog.transfer_control(_PROCESSES[-1].pid)
     log.info("Spawning discovery process...")
     _PROCESSES.append(
-        mpm.spawn_discovery_process(shared, args.discovery_addr)
+        mpm.discovery.spawn_discovery_process(shared, args.discovery_addr)
     )
     log.debug("Discovery process has PID: %d", _PROCESSES[-1].pid)
     log.info("Processes launched. Registering signal handlers.")

mpm/python/usrp_mpm/__init__.py.in

@@ -9,8 +9,6 @@ MPM Module
 
 __simulated__ = ("${MPM_DEVICE}" == "sim")
 
-from .discovery import spawn_discovery_process
-from .rpc_server import spawn_rpc_process
 from . import compat_num
 from . import mpmtypes
 from . import gpsd_iface

mpm/python/usrp_mpm/components.py

@@ -10,7 +10,7 @@ import os
 import re
 import shutil
 import subprocess
-from usrp_mpm.rpc_server import no_rpc
+from usrp_mpm.rpc_utils import no_rpc
 
 
 class ZynqComponents:

mpm/python/usrp_mpm/dboard_manager/x4xx_db.py

@@ -10,7 +10,7 @@ Mixin class for daughterboard classes that live on a X4xx motherboard
 from usrp_mpm.mpmlog import get_logger
 from usrp_mpm import tlv_eeprom
 from usrp_mpm.sys_utils.udev import get_eeprom_paths_by_symbol
-from usrp_mpm.rpc_server import no_rpc
+from usrp_mpm.rpc_utils import no_rpc
 
 # pylint: disable=too-few-public-methods
 class EepromTagMap:

mpm/python/usrp_mpm/periph_manager/base.py

@@ -22,7 +22,7 @@ from usrp_mpm.sys_utils.udev import get_spidev_nodes
 from usrp_mpm.sys_utils import dtoverlay
 from usrp_mpm.sys_utils import net
 from usrp_mpm.xports import XportAdapterMgr
-from usrp_mpm.rpc_server import no_claim, no_rpc
+from usrp_mpm.rpc_utils import no_claim, no_rpc
 from usrp_mpm.mpmutils import get_dboard_class_from_pid
 from usrp_mpm import eeprom
 from usrp_mpm import prefs

mpm/python/usrp_mpm/periph_manager/e31x.py

@@ -16,7 +16,7 @@ from usrp_mpm.dboard_manager import E31x_db
 from usrp_mpm.gpsd_iface import GPSDIfaceExtension
 from usrp_mpm.mpmutils import assert_compat_number, str2bool
 from usrp_mpm.periph_manager import PeriphManagerBase
-from usrp_mpm.rpc_server import no_rpc, _get_map_for_rpc
+from usrp_mpm.rpc_utils import no_rpc, get_map_for_rpc
 from usrp_mpm.sys_utils import dtoverlay
 from usrp_mpm.sys_utils.sysfs_thermal import read_sysfs_sensors_value
 from usrp_mpm.sys_utils.udev import get_spidev_nodes
@@ -696,7 +696,7 @@ class e31x(ZynqComponents, PeriphManagerBase):
         mboard info again. This filters the EEPROM contents to what we think
         the user wants to know/see.
         """
-        return _get_map_for_rpc(self.mboard_info, self.log)
+        return get_map_for_rpc(self.mboard_info, self.log)
 
     def set_mb_eeprom(self, _eeprom_vals):
         """

mpm/python/usrp_mpm/periph_manager/e320.py

@@ -18,7 +18,7 @@ from usrp_mpm.dboard_manager import Neon
 from usrp_mpm.gpsd_iface import GPSDIfaceExtension
 from usrp_mpm.mpmutils import assert_compat_number, str2bool
 from usrp_mpm.periph_manager import PeriphManagerBase
-from usrp_mpm.rpc_server import no_rpc, _get_map_for_rpc
+from usrp_mpm.rpc_utils import no_rpc, get_map_for_rpc
 from usrp_mpm.sys_utils import dtoverlay
 from usrp_mpm.sys_utils.sysfs_thermal import read_thermal_sensor_value, read_thermal_sensors_value
 from usrp_mpm.sys_utils.udev import get_spidev_nodes
@@ -647,7 +647,7 @@ class e320(ZynqComponents, PeriphManagerBase):
         mboard info again. This filters the EEPROM contents to what we think
         the user wants to know/see.
         """
-        return _get_map_for_rpc(self.mboard_info, self.log)
+        return get_map_for_rpc(self.mboard_info, self.log)
 
     def set_mb_eeprom(self, eeprom_vals):
         """

mpm/python/usrp_mpm/periph_manager/n3xx.py

@@ -18,7 +18,7 @@ from usrp_mpm.components import ZynqComponents
 from usrp_mpm.gpsd_iface import GPSDIfaceExtension
 from usrp_mpm.periph_manager import PeriphManagerBase
 from usrp_mpm.mpmutils import assert_compat_number, str2bool, poll_with_timeout
-from usrp_mpm.rpc_server import no_rpc, _get_map_for_rpc
+from usrp_mpm.rpc_utils import no_rpc, get_map_for_rpc
 from usrp_mpm.sys_utils import dtoverlay
 from usrp_mpm.sys_utils import i2c_dev
 from usrp_mpm.sys_utils.sysfs_thermal import read_thermal_sensor_value
@@ -927,7 +927,7 @@ class n3xx(ZynqComponents, PeriphManagerBase):
         mboard info again. This filters the EEPROM contents to what we think
         the user wants to know/see.
         """
-        return _get_map_for_rpc(self.mboard_info, self.log)
+        return get_map_for_rpc(self.mboard_info, self.log)
 
     def get_db_eeprom(self, dboard_idx):
         """

mpm/python/usrp_mpm/periph_manager/sim.py

@@ -13,7 +13,7 @@ configuration by using the cmake flag -DMPM_DEVICE=sim
 from pyroute2 import IPRoute
 from usrp_mpm.xports import XportMgrUDP
 from usrp_mpm.mpmlog import get_logger
-from usrp_mpm.rpc_server import no_claim
+from usrp_mpm.rpc_utils import no_claim
 from usrp_mpm.periph_manager import PeriphManagerBase
 from usrp_mpm.simulator.sim_dboard import registry as dboards
 from usrp_mpm.simulator.chdr_endpoint import ChdrEndpoint

mpm/python/usrp_mpm/periph_manager/x4xx.py

@@ -21,7 +21,7 @@ from usrp_mpm.sys_utils import ectool
 from usrp_mpm.sys_utils import i2c_dev
 from usrp_mpm.sys_utils.gpio import Gpio
 from usrp_mpm.sys_utils.udev import dt_symbol_get_spidev
-from usrp_mpm.rpc_server import no_claim, no_rpc
+from usrp_mpm.rpc_utils import no_claim, no_rpc
 from usrp_mpm.mpmutils import assert_compat_number, poll_with_timeout
 from usrp_mpm.periph_manager import PeriphManagerBase
 from usrp_mpm.xports import XportMgrUDP

mpm/python/usrp_mpm/periph_manager/x4xx_clock_mgr.py

@@ -45,7 +45,7 @@ from usrp_mpm.mpmutils import parse_multi_device_arg, str2bool
 from usrp_mpm.periph_manager.x4xx_clk_aux import ClockingAuxBrdControl
 from usrp_mpm.periph_manager.x4xx_clock_types import RpllRefSel, BrcSource
 from usrp_mpm.periph_manager.x4xx_clock_ctrl import X4xxClockCtrl
-from usrp_mpm.rpc_server import no_rpc
+from usrp_mpm.rpc_utils import no_rpc
 
 class X4xxClockManager:
     """

mpm/python/usrp_mpm/periph_manager/x4xx_rfdc_ctrl.py

@@ -12,7 +12,7 @@ import itertools
 from dataclasses import dataclass
 from usrp_mpm import lib # Pulls in everything from C++-land
 from usrp_mpm.periph_manager.x4xx_rfdc_regs import RfdcRegsControl
-from usrp_mpm.rpc_server import no_rpc
+from usrp_mpm.rpc_utils import no_rpc
 from usrp_mpm.mpmutils import LogRuntimeError
 
 RFDC_DEVICE_ID = 0

mpm/python/usrp_mpm/rpc_server.py

@@ -29,6 +29,8 @@ from usrp_mpm.mpmlog import get_main_logger
 from usrp_mpm.mpmutils import to_binary_str
 from usrp_mpm.sys_utils import watchdog
 from usrp_mpm.sys_utils import net
+from usrp_mpm.rpc_utils import get_map_for_rpc
+
 
 TIMEOUT_INTERVAL = 5.0 # Seconds before claim expires (default value)
 LOCK_ACQ_TIMEOUT = 1 # Seconds to wait for acquiring shared lock (default value)
@@ -36,16 +38,6 @@ TOKEN_LEN = 16 # Length of the token string
 # Compatibility number for MPM
 MPM_COMPAT_NUM = (5, 3)
 
-def no_claim(func):
-    " Decorator for functions that require no token check "
-    func._notok = True
-    return func
-
-def no_rpc(func):
-    " Decorator for functions that should not be exposed via RPC "
-    func._norpc = True
-    return func
-
 class MPMServer(RPCServer):
     """
     Main MPM RPC class which holds the periph_manager object and translates
@@ -442,7 +434,7 @@ class MPMServer(RPCServer):
         get device information
         This is as safe method which can be called without a claim on the device
         """
-        info = _get_map_for_rpc(self.periph_manager.get_device_info(), self.log)
+        info = get_map_for_rpc(self.periph_manager.get_device_info(), self.log)
         info["mpm_version"] = "{}.{}".format(*MPM_COMPAT_NUM)
         if _is_connection_local(self.client_host):
             info["connection"] = "local"
@@ -654,16 +646,3 @@ def spawn_rpc_process(state, udp_port, default_args):
     )
     proc.start()
     return proc
-
-
-def _get_map_for_rpc(map, log):
-    """
-    ensure the map contains only string values otherwise it cannot be
-    casted to std::map<string, string> in C++
-    # TODO reconsider the workaround once we transition away from mprpc
-    """
-    for key, value in map.items():
-        if value is None:
-            log.warning('casting parameter "{}" from None to "n/a"'.format(key))
-            map[key] = "n/a"
-    return map

mpm/python/usrp_mpm/rpc_utils.py

@@ -0,0 +1,31 @@
+#!/usr/bin/env python3
+#
+# Copyright 2018 Ettus Research, a National Instruments Company
+#
+# SPDX-License-Identifier: GPL-3.0-or-later
+#
+"""
+Implements decorators and utility functions to be used with the RPC server
+"""
+
+def no_claim(func):
+    " Decorator for functions that require no token check "
+    func._notok = True
+    return func
+
+def no_rpc(func):
+    " Decorator for functions that should not be exposed via RPC "
+    func._norpc = True
+    return func
+
+def get_map_for_rpc(map, log):
+    """
+    ensure the map contains only string values otherwise it cannot be
+    casted to std::map<string, string> in C++
+    # TODO reconsider the workaround once we transition away from mprpc
+    """
+    for key, value in map.items():
+        if value is None:
+            log.warning('casting parameter "{}" from None to "n/a"'.format(key))
+            map[key] = "n/a"
+    return map