ec3po: Update platform/ec/ side of ec3po to use threadproc_shim.py.

This removes direct use of multiprocessing module from the platform/ec/
side of ec3po.  Once the third_party/hdctools/ side has been updated to use
threadproc_shim.py as well, that library can be updated with
threading-oriented implementations.

BRANCH=none
BUG=b:79684405
TEST=With a servo_micro connected to an octopus_ite, functionality
involving the EC console continues to work.  I tested dut-control
ec_uart_pty (including using the UART with minicom), dut_i2c_mux,
enable_ite_dfu, get_ite_chipid commands.

Change-Id: I68eb2d8cd1d927d63b12696938169281e51de6fc
Signed-off-by: Matthew Blecker <matthewb@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/1279153
Reviewed-by: Ruben Rodriguez Buchillon <coconutruben@chromium.org>

4 files changed, 47 insertions, 45 deletions

diff --git a/util/ec3po/console.py b/util/ec3po/console.py
index 29fc705d61..61d2315e7c 100755
--- a/util/ec3po/console.py
+++ b/util/ec3po/console.py
@@ -17,7 +17,6 @@ import ctypes
 import binascii
 # pylint: disable=cros-logging-import
 import logging
-import multiprocessing
 import os
 import pty
 import re
@@ -27,6 +26,7 @@ import sys
 import traceback
 
 import interpreter
+import threadproc_shim
 
 
 PROMPT = '> '
@@ -96,14 +96,15 @@ class Console(object):
     master_pty: File descriptor to the master side of the PTY.  Used for driving
       output to the user and receiving user input.
     user_pty: A string representing the PTY name of the served console.
-    cmd_pipe: A multiprocessing.Connection object which represents the console
-      side of the command pipe.  This must be a bidirectional pipe.  Console
-      commands and responses utilize this pipe.
-    dbg_pipe: A multiprocessing.Connection object which represents the console's
-      read-only side of the debug pipe.  This must be a unidirectional pipe
-      attached to the intepreter.  EC debug messages use this pipe.
-    oobm_queue: A multiprocessing.Queue which is used for out of band management
-      for the interactive console.
+    cmd_pipe: A socket.socket or multiprocessing.Connection object which
+      represents the console side of the command pipe.  This must be a
+      bidirectional pipe.  Console commands and responses utilize this pipe.
+    dbg_pipe: A socket.socket or multiprocessing.Connection object which
+      represents the console's read-only side of the debug pipe.  This must be a
+      unidirectional pipe attached to the intepreter.  EC debug messages use
+      this pipe.
+    oobm_queue: A Queue.Queue or multiprocessing.Queue which is used for out of
+      band management for the interactive console.
     input_buffer: A string representing the current input command.
     input_buffer_pos: An integer representing the current position in the buffer
       to insert a char.
@@ -139,12 +140,13 @@ class Console(object):
     user_pty: A string representing the PTY name of the served console.
     interface_pty: A string representing the PTY name of the served command
       interface.
-    cmd_pipe: A multiprocessing.Connection object which represents the console
-      side of the command pipe.  This must be a bidirectional pipe.  Console
-      commands and responses utilize this pipe.
-    dbg_pipe: A multiprocessing.Connection object which represents the console's
-      read-only side of the debug pipe.  This must be a unidirectional pipe
-      attached to the intepreter.  EC debug messages use this pipe.
+    cmd_pipe: A socket.socket or multiprocessing.Connection object which
+      represents the console side of the command pipe.  This must be a
+      bidirectional pipe.  Console commands and responses utilize this pipe.
+    dbg_pipe: A socket.socket or multiprocessing.Connection object which
+      represents the console's read-only side of the debug pipe.  This must be a
+      unidirectional pipe attached to the intepreter.  EC debug messages use
+      this pipe.
     """
     logger = logging.getLogger('EC3PO.Console')
     self.logger = interpreter.LoggerAdapter(logger, {'pty': user_pty})
@@ -153,7 +155,7 @@ class Console(object):
     self.interface_pty = interface_pty
     self.cmd_pipe = cmd_pipe
     self.dbg_pipe = dbg_pipe
-    self.oobm_queue = multiprocessing.Queue()
+    self.oobm_queue = threadproc_shim.Queue()
     self.input_buffer = ''
     self.input_buffer_pos = 0
     self.partial_cmd = ''
@@ -822,8 +824,9 @@ def StartLoop(console, command_active, shutdown_pipe=None):
 
   Args:
     console: A Console object that has been properly initialzed.
-    command_active: multiprocessing.Value indicating if servod owns
-        the console, or user owns the console. This prevents input collisions.
+    command_active: ctypes data object or multiprocessing.Value indicating if
+      servod owns the console, or user owns the console. This prevents input
+      collisions.
     shutdown_pipe: A file object for a pipe or equivalent that becomes readable
       (not blocked) to indicate that the loop should exit.  Can be None to never
       exit the loop.
@@ -987,17 +990,17 @@ def main(argv):
 
   # Create some pipes to communicate between the interpreter and the console.
   # The command pipe is bidirectional.
-  cmd_pipe_interactive, cmd_pipe_interp = multiprocessing.Pipe()
+  cmd_pipe_interactive, cmd_pipe_interp = threadproc_shim.Pipe()
   # The debug pipe is unidirectional from interpreter to console only.
-  dbg_pipe_interactive, dbg_pipe_interp = multiprocessing.Pipe(duplex=False)
+  dbg_pipe_interactive, dbg_pipe_interp = threadproc_shim.Pipe(duplex=False)
 
   # Create an interpreter instance.
   itpr = interpreter.Interpreter(opts.ec_uart_pty, cmd_pipe_interp,
                                  dbg_pipe_interp, log_level)
 
   # Spawn an interpreter process.
-  itpr_process = multiprocessing.Process(target=interpreter.StartLoop,
-                                         args=(itpr,))
+  itpr_process = threadproc_shim.ThreadOrProcess(
+      target=interpreter.StartLoop, args=(itpr,))
   # Make sure to kill the interpreter when we terminate.
   itpr_process.daemon = True
   # Start the interpreter.
@@ -1012,7 +1015,7 @@ def main(argv):
   console = Console(master_pty, os.ttyname(user_pty), cmd_pipe_interactive,
                     dbg_pipe_interactive)
   # Start serving the console.
-  v = multiprocessing.Value(ctypes.c_bool, False)
+  v = threadproc_shim.Value(ctypes.c_bool, False)
   StartLoop(console, v)
 
 
diff --git a/util/ec3po/console_unittest.py b/util/ec3po/console_unittest.py
index 1e9dae9efd..22d468263b 100755
--- a/util/ec3po/console_unittest.py
+++ b/util/ec3po/console_unittest.py
@@ -11,12 +11,12 @@ import binascii
 # pylint: disable=cros-logging-import
 import logging
 import mock
-import multiprocessing
 import tempfile
 import unittest
 
 import console
 import interpreter
+import threadproc_shim
 
 ESC_STRING = chr(console.ControlKey.ESC)
 
@@ -238,7 +238,7 @@ class TestConsoleEditingMethods(unittest.TestCase):
 
     # Create some dummy pipes.  These won't be used since we'll mock out sends
     # to the interpreter.
-    dummy_pipe_end_0, dummy_pipe_end_1 = multiprocessing.Pipe()
+    dummy_pipe_end_0, dummy_pipe_end_1 = threadproc_shim.Pipe()
     self.console = console.Console(self.tempfile.fileno(), self.tempfile,
                                    tempfile.TemporaryFile(),
                                    dummy_pipe_end_0, dummy_pipe_end_1)
@@ -250,9 +250,6 @@ class TestConsoleEditingMethods(unittest.TestCase):
     self.console.enhanced_ec = True
     self.console.CheckForEnhancedECImage = mock.MagicMock(return_value=True)
 
-    # Mock out sends to the interpreter.
-    multiprocessing.Pipe.send = mock.MagicMock()
-
   def test_EnteringChars(self):
     """Verify that characters are echoed onto the console."""
     test_str = 'abc'
diff --git a/util/ec3po/interpreter.py b/util/ec3po/interpreter.py
index 3957466dbf..e713c32f1a 100644
--- a/util/ec3po/interpreter.py
+++ b/util/ec3po/interpreter.py
@@ -47,12 +47,13 @@ class Interpreter(object):
     logger: A logger for this module.
     ec_uart_pty: An opened file object to the raw EC UART PTY.
     ec_uart_pty_name: A string containing the name of the raw EC UART PTY.
-    cmd_pipe: A multiprocessing.Connection object which represents the
-      Interpreter side of the command pipe.  This must be a bidirectional pipe.
-      Commands and responses will utilize this pipe.
-    dbg_pipe: A multiprocessing.Connection object which represents the
-      Interpreter side of the debug pipe. This must be a unidirectional pipe
-      with write capabilities.  EC debug output will utilize this pipe.
+    cmd_pipe: A socket.socket or multiprocessing.Connection object which
+      represents the Interpreter side of the command pipe.  This must be a
+      bidirectional pipe.  Commands and responses will utilize this pipe.
+    dbg_pipe: A socket.socket or multiprocessing.Connection object which
+      represents the Interpreter side of the debug pipe. This must be a
+      unidirectional pipe with write capabilities.  EC debug output will utilize
+      this pipe.
     cmd_retries: An integer representing the number of attempts the console
       should retry commands if it receives an error.
     log_level: An integer representing the numeric value of the log level.
@@ -77,12 +78,13 @@ class Interpreter(object):
 
     Args:
       ec_uart_pty: A string representing the EC UART to connect to.
-      cmd_pipe: A multiprocessing.Connection object which represents the
-        Interpreter side of the command pipe.  This must be a bidirectional
-        pipe.  Commands and responses will utilize this pipe.
-      dbg_pipe: A multiprocessing.Connection object which represents the
-        Interpreter side of the debug pipe. This must be a unidirectional pipe
-        with write capabilities.  EC debug output will utilize this pipe.
+      cmd_pipe: A socket.socket or multiprocessing.Connection object which
+        represents the Interpreter side of the command pipe.  This must be a
+        bidirectional pipe.  Commands and responses will utilize this pipe.
+      dbg_pipe: A socket.socket or multiprocessing.Connection object which
+        represents the Interpreter side of the debug pipe. This must be a
+        unidirectional pipe with write capabilities.  EC debug output will
+        utilize this pipe.
       cmd_retries: An integer representing the number of attempts the console
         should retry commands if it receives an error.
       log_level: An optional integer representing the numeric value of the log
diff --git a/util/ec3po/interpreter_unittest.py b/util/ec3po/interpreter_unittest.py
index 6eb6b3abda..8b9578a242 100755
--- a/util/ec3po/interpreter_unittest.py
+++ b/util/ec3po/interpreter_unittest.py
@@ -10,11 +10,11 @@ from __future__ import print_function
 # pylint: disable=cros-logging-import
 import logging
 import mock
-import multiprocessing
 import tempfile
 import unittest
 
 import interpreter
+import threadproc_shim
 
 class TestEnhancedECBehaviour(unittest.TestCase):
   """Test case to verify all enhanced EC interpretation tasks."""
@@ -29,8 +29,8 @@ class TestEnhancedECBehaviour(unittest.TestCase):
     self.tempfile = tempfile.NamedTemporaryFile()
 
     # Create the pipes that the interpreter will use.
-    self.cmd_pipe_user, self.cmd_pipe_itpr = multiprocessing.Pipe()
-    self.dbg_pipe_user, self.dbg_pipe_itpr = multiprocessing.Pipe(duplex=False)
+    self.cmd_pipe_user, self.cmd_pipe_itpr = threadproc_shim.Pipe()
+    self.dbg_pipe_user, self.dbg_pipe_itpr = threadproc_shim.Pipe(duplex=False)
 
     # Mock the open() function so we can inspect reads/writes to the EC.
     self.ec_uart_pty = mock.mock_open()
@@ -264,8 +264,8 @@ class TestUARTDisconnection(unittest.TestCase):
     self.tempfile = tempfile.NamedTemporaryFile()
 
     # Create the pipes that the interpreter will use.
-    self.cmd_pipe_user, self.cmd_pipe_itpr = multiprocessing.Pipe()
-    self.dbg_pipe_user, self.dbg_pipe_itpr = multiprocessing.Pipe(duplex=False)
+    self.cmd_pipe_user, self.cmd_pipe_itpr = threadproc_shim.Pipe()
+    self.dbg_pipe_user, self.dbg_pipe_itpr = threadproc_shim.Pipe(duplex=False)
 
     # Mock the open() function so we can inspect reads/writes to the EC.
     self.ec_uart_pty = mock.mock_open()