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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [qemu-xen staging] python/qemu: Change ConsoleSocket to optionally drain socket.
commit 80ded8e99d9fc44c206f6b2fae6638df7dcf9305
Author: Robert Foley <robert.foley@xxxxxxxxxx>
AuthorDate: Fri Jul 24 07:45:08 2020 +0100
Commit: Alex Bennée <alex.bennee@xxxxxxxxxx>
CommitDate: Mon Jul 27 09:41:56 2020 +0100
python/qemu: Change ConsoleSocket to optionally drain socket.
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@xxxxxxxxxx>
Signed-off-by: Alex Bennée <alex.bennee@xxxxxxxxxx>
Message-Id: <20200717203041.9867-3-robert.foley@xxxxxxxxxx>
Message-Id: <20200724064509.331-16-alex.bennee@xxxxxxxxxx>
---
python/qemu/console_socket.py | 92 ++++++++++++++++++++++++++-----------------
python/qemu/machine.py | 13 ++----
2 files changed, 59 insertions(+), 46 deletions(-)
diff --git a/python/qemu/console_socket.py b/python/qemu/console_socket.py
index 09986bc215..70869fbbdc 100644
--- a/python/qemu/console_socket.py
+++ b/python/qemu/console_socket.py
@@ -13,68 +13,75 @@ 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)
+ 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"""
- 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.
@@ -85,27 +92,38 @@ class ConsoleSocket(asyncore.dispatcher):
for c in string:
self._buffer.extend(c)
- def recv(self, buffer_size=1):
+ 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) < buffer_size:
+ 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(buffer_size)])
+ 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)
diff --git a/python/qemu/machine.py b/python/qemu/machine.py
index a09768e9f9..82f3731fc3 100644
--- a/python/qemu/machine.py
+++ b/python/qemu/machine.py
@@ -23,7 +23,6 @@ import os
import subprocess
import shutil
import signal
-import socket
import tempfile
from typing import Optional, Type
from types import TracebackType
@@ -673,12 +672,8 @@ 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
--
generated by git-patchbot for /home/xen/git/qemu-xen.git#staging
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