console: Update socket timeout functionality for Macs
This adjusts the original timeout code to use getsockopt(..., SO_NWRITE) to get
the number of sent but not acknowledged bytes. This is supported on all
BSD-derived/POSIX compliant systems since 4.3 BSD, but apparently Linux is the
sole outlier and only supports the fcntl() method.
Change-Id: I6ad4cb8d3f5e04d70bfbfa855de133674087814b
diff --git a/mdt/console.py b/mdt/console.py
index 5e31fcb..d01aa76 100644
--- a/mdt/console.py
+++ b/mdt/console.py
@@ -53,7 +53,7 @@
self.channel = channel
self.inputfile = inputfile
self.has_tty = False
- self.linux = os.uname()[0] == 'Linux'
+ self.uname = os.uname()
def _updateWindowSize(self, signum, stackFrame):
if self.has_tty:
@@ -61,15 +61,20 @@
self.channel.resize_pty(columns, rows, 0, 0)
def _socketSendQueueLevel(self):
- # Only supported on Linux
- if not self.linux:
- return 0
-
import fcntl
+ import socket
import struct
+
SIOCOUTQ = 0x5411
+ SO_NWRITE = 0x1024
sock = self.channel.get_transport().sock
- return struct.unpack("I", fcntl.ioctl(sock.fileno(), SIOCOUTQ, '\0\0\0\0'))[0]
+
+ # Only Linux doesn't support SO_NWRITE, which has been available since 4.3 BSD. O.o
+ if uname == "Linux":
+ return struct.unpack("I", fcntl.ioctl(sock.fileno(), SIOCOUTQ, '\0\0\0\0'))[0]
+
+ return sock.getsockopt(socket.SOL_SOCKET, SO_NWRITE)
+
def run(self):
import termios
@@ -108,24 +113,26 @@
try:
self.channel.settimeout(0)
self.channel.get_transport().set_keepalive(KEEP_ALIVE_SECONDS)
- timeouts = 0
- tx_level = 0
+ timeout_count = 0
+ initial_tx_level = 0
while True:
read, write, exception = select.select([self.channel,
self.inputfile],
[], [], KEEP_ALIVE_SECONDS + 1)
- timeout = not read and not write and not exception
- if self.linux and timeout:
- timeouts += 1
- if timeouts == 1:
- tx_level = self._socketSendQueueLevel()
+
+ select_timedout = not read and not write and not exception
+ if select_timedout:
+ timeout_count += 1
+
+ if timeout_count == 1:
+ initial_tx_level = self._socketSendQueueLevel()
else:
current_tx_level = self._socketSendQueueLevel()
- if current_tx_level and current_tx_level >= tx_level:
+ if current_tx_level and current_tx_level >= initial_tx_level:
raise SocketTimeoutError(socket.timeout())
else:
- timeouts = 0
+ timeout_count = 0
# data from device to host
if self.channel in read:
