diff options
Diffstat (limited to 'python/qemu/console_socket.py')
| -rw-r--r-- | python/qemu/console_socket.py | 137 |
1 files changed, 78 insertions, 59 deletions
diff --git a/python/qemu/console_socket.py b/python/qemu/console_socket.py index 830cb7c628..70869fbbdc 100644 --- a/python/qemu/console_socket.py +++ b/python/qemu/console_socket.py @@ -1,12 +1,9 @@ -#!/usr/bin/env python3 -# -# This python module implements a ConsoleSocket object which is -# designed always drain the socket itself, and place -# the bytes into a in memory buffer for later processing. -# -# Optionally a file path can be passed in and we will also -# dump the characters to this file for debug. -# +""" +QEMU Console Socket Module: + +This python module implements a ConsoleSocket object, +which can drain a socket and optionally dump the bytes to file. +""" # Copyright 2020 Linaro # # Authors: @@ -15,96 +12,118 @@ # This code is licensed under the GPL version 2 or later. See # the COPYING file in the top-level directory. # -import asyncore + import socket import threading -import io -import os -import sys from collections import deque import time -import traceback -class ConsoleSocket(asyncore.dispatcher): - def __init__(self, address, file=None): +class ConsoleSocket(socket.socket): + """ + ConsoleSocket represents a socket attached to a char device. + + Optionally (if drain==True), drains the socket and places the bytes + into an in memory buffer for later processing. + + Optionally a file path can be passed in and we will also + dump the characters to this file for debugging purposes. + """ + def __init__(self, address, file=None, drain=False): self._recv_timeout_sec = 300 + self._sleep_time = 0.5 self._buffer = deque() - self._asyncore_thread = None - self._sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM) - self._sock.connect(address) + socket.socket.__init__(self, socket.AF_UNIX, socket.SOCK_STREAM) + self.connect(address) self._logfile = None if file: self._logfile = open(file, "w") - asyncore.dispatcher.__init__(self, sock=self._sock) self._open = True - self._thread_start() + if drain: + self._drain_thread = self._thread_start() + else: + self._drain_thread = None - def _thread_start(self): - """Kick off a thread to wait on the asyncore.loop""" - if self._asyncore_thread is not None: - return - self._asyncore_thread = threading.Thread(target=asyncore.loop, - kwargs={'timeout':1}) - self._asyncore_thread.daemon = True - self._asyncore_thread.start() + def _drain_fn(self): + """Drains the socket and runs while the socket is open.""" + while self._open: + try: + self._drain_socket() + except socket.timeout: + # The socket is expected to timeout since we set a + # short timeout to allow the thread to exit when + # self._open is set to False. + time.sleep(self._sleep_time) - def handle_close(self): - """redirect close to base class""" - # Call the base class close, but not self.close() since - # handle_close() occurs in the context of the thread which - # self.close() attempts to join. - asyncore.dispatcher.close(self) + def _thread_start(self): + """Kick off a thread to drain the socket.""" + # Configure socket to not block and timeout. + # This allows our drain thread to not block + # on recieve and exit smoothly. + socket.socket.setblocking(self, False) + socket.socket.settimeout(self, 1) + drain_thread = threading.Thread(target=self._drain_fn) + drain_thread.daemon = True + drain_thread.start() + return drain_thread def close(self): """Close the base object and wait for the thread to terminate""" if self._open: self._open = False - asyncore.dispatcher.close(self) - if self._asyncore_thread is not None: - thread, self._asyncore_thread = self._asyncore_thread, None + if self._drain_thread is not None: + thread, self._drain_thread = self._drain_thread, None thread.join() + socket.socket.close(self) if self._logfile: self._logfile.close() self._logfile = None - def handle_read(self): + def _drain_socket(self): """process arriving characters into in memory _buffer""" - try: - data = asyncore.dispatcher.recv(self, 1) - # latin1 is needed since there are some chars - # we are receiving that cannot be encoded to utf-8 - # such as 0xe2, 0x80, 0xA6. - string = data.decode("latin1") - except: - print("Exception seen.") - traceback.print_exc() - return + data = socket.socket.recv(self, 1) + # latin1 is needed since there are some chars + # we are receiving that cannot be encoded to utf-8 + # such as 0xe2, 0x80, 0xA6. + string = data.decode("latin1") if self._logfile: self._logfile.write("{}".format(string)) self._logfile.flush() for c in string: self._buffer.extend(c) - def recv(self, n=1, sleep_delay_s=0.1): - """Return chars from in memory buffer""" + def recv(self, bufsize=1): + """Return chars from in memory buffer. + Maintains the same API as socket.socket.recv. + """ + if self._drain_thread is None: + # Not buffering the socket, pass thru to socket. + return socket.socket.recv(self, bufsize) start_time = time.time() - while len(self._buffer) < n: - time.sleep(sleep_delay_s) + while len(self._buffer) < bufsize: + time.sleep(self._sleep_time) elapsed_sec = time.time() - start_time if elapsed_sec > self._recv_timeout_sec: raise socket.timeout - chars = ''.join([self._buffer.popleft() for i in range(n)]) + chars = ''.join([self._buffer.popleft() for i in range(bufsize)]) # We choose to use latin1 to remain consistent with # handle_read() and give back the same data as the user would # receive if they were reading directly from the # socket w/o our intervention. return chars.encode("latin1") - def set_blocking(self): - """Maintain compatibility with socket API""" - pass + def setblocking(self, value): + """When not draining we pass thru to the socket, + since when draining we control socket blocking. + """ + if self._drain_thread is None: + socket.socket.setblocking(self, value) def settimeout(self, seconds): - """Set current timeout on recv""" - self._recv_timeout_sec = seconds + """When not draining we pass thru to the socket, + since when draining we control the timeout. + """ + if seconds is not None: + self._recv_timeout_sec = seconds + if self._drain_thread is None: + socket.socket.settimeout(self, seconds) |