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[PATCH 2/2] python/qemu: Change ConsoleSocket to optionally drain socket
From: |
Robert Foley |
Subject: |
[PATCH 2/2] python/qemu: Change ConsoleSocket to optionally drain socket. |
Date: |
Wed, 15 Jul 2020 16:48:14 -0400 |
The primary purpose of this change is to clean up
machine.py's console_socket property to return a single type,
a ConsoleSocket.
ConsoleSocket now derives from a socket, which means that
in the default case (of not draining), machine.py
will see the same behavior as it did prior to ConsoleSocket.
Signed-off-by: Robert Foley <robert.foley@linaro.org>
---
python/qemu/console_socket.py | 81 +++++++++++++++++++++--------------
python/qemu/machine.py | 13 ++----
2 files changed, 54 insertions(+), 40 deletions(-)
diff --git a/python/qemu/console_socket.py b/python/qemu/console_socket.py
index 6a746c1dbf..475de5b101 100644
--- a/python/qemu/console_socket.py
+++ b/python/qemu/console_socket.py
@@ -13,68 +13,76 @@ which can drain a socket and optionally dump the bytes to
file.
# the COPYING file in the top-level directory.
#
-import asyncore
import socket
import threading
from collections import deque
import time
-class ConsoleSocket(asyncore.dispatcher):
+class ConsoleSocket(socket.socket):
"""
ConsoleSocket represents a socket attached to a char device.
- Drains the socket and places the bytes into an in memory buffer
- for later processing.
+ 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):
+ 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)
+ self._drain_thread = None
+ socket.socket.__init__(self, socket.AF_UNIX, socket.SOCK_STREAM)
+ self.connect(address)
+ self._drain = drain
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._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 _thread_start(self):
- """Kick off a thread to wait on the asyncore.loop"""
- if self._asyncore_thread is not None:
+ """Kick off a thread to drain the socket."""
+ if self._drain_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 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)
+ # Configure socket to not block and timeout.
+ # This allows our drain thread to not block
+ # on recieve and exit smoothly.
+ socket.socket.setblocking(self, 0)
+ socket.socket.settimeout(self, 1)
+ self._drain_thread = threading.Thread(target=self._drain_fn)
+ self._drain_thread.daemon = True
+ self._drain_thread.start()
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 and 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"""
- data = asyncore.dispatcher.recv(self, 1)
+ 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.
@@ -89,6 +97,9 @@ class ConsoleSocket(asyncore.dispatcher):
"""Return chars from in memory buffer.
Maintains the same API as socket.socket.recv.
"""
+ if not self._drain:
+ # Not buffering the socket, pass thru to socket.
+ return socket.socket.recv(self, buffer_size)
start_time = time.time()
while len(self._buffer) < buffer_size:
time.sleep(self._sleep_time)
@@ -102,9 +113,17 @@ class ConsoleSocket(asyncore.dispatcher):
# socket w/o our intervention.
return chars.encode("latin1")
- def set_blocking(self):
- """Maintain compatibility with socket API"""
+ def setblocking(self, value):
+ """When not draining we pass thru to the socket,
+ since when draining we control socket blocking.
+ """
+ if not self._drain:
+ socket.socket.setblocking(self, value)
def settimeout(self, seconds):
- """Set current timeout on recv"""
+ """When not draining we pass thru to the socket,
+ since when draining we control the timeout.
+ """
self._recv_timeout_sec = seconds
+ if not self._drain:
+ socket.socket.settimeout(self, seconds)
diff --git a/python/qemu/machine.py b/python/qemu/machine.py
index 6769359766..62709d86e4 100644
--- a/python/qemu/machine.py
+++ b/python/qemu/machine.py
@@ -22,7 +22,6 @@ import logging
import os
import subprocess
import shutil
-import socket
import tempfile
from typing import Optional, Type
from types import TracebackType
@@ -591,12 +590,8 @@ class QEMUMachine:
Returns a socket connected to the console
"""
if self._console_socket is None:
- if self._drain_console:
- self._console_socket = console_socket.ConsoleSocket(
- self._console_address,
- file=self._console_log_path)
- else:
- self._console_socket = socket.socket(socket.AF_UNIX,
- socket.SOCK_STREAM)
- self._console_socket.connect(self._console_address)
+ self._console_socket = console_socket.ConsoleSocket(
+ self._console_address,
+ file=self._console_log_path,
+ drain=self._drain_console)
return self._console_socket
--
2.17.1
[PATCH 2/2] python/qemu: Change ConsoleSocket to optionally drain socket.,
Robert Foley <=