以下は、私が使用することになった回避策です。adbの障害が発生する可能性のある関数は、次のデコレータを使用する必要があります。
from subprocess import call, PIPE, Popen
from time import sleep
def check_connection(f):
"""
adb is unstable and cannot be trusted. When there's a problem, a
SocketException will be thrown, but caught internally by MonkeyRunner
and simply logged. As a hacky solution, this checks if the stderr log
grows after f is called (a false positive isn't going to cause any harm).
If so, the connection will be repaired and the decorated function/method
will be called again.
Make sure that stderr is redirected at the command line to the file
specified by config.STDERR. Also, this decorator will only work for
functions/methods that take a Device object as the first argument.
"""
def wrapper(*args, **kwargs):
while True:
cmd = "wc -l %s | awk '{print $1}'" % config.STDERR
p = Popen(cmd, shell=True, stdout=PIPE)
(line_count_pre, stderr) = p.communicate()
line_count_pre = line_count_pre.strip()
f(*args, **kwargs)
p = Popen(cmd, shell=True, stdout=PIPE)
(line_count_post, stderr) = p.communicate()
line_count_post = line_count_post.strip()
if line_count_pre == line_count_post:
# the connection was fine
break
print 'Connection error. Restarting adb...'
sleep(1)
call('adb kill-server', shell=True)
call('adb start-server', shell=True)
args[0].connection = MonkeyRunner.waitForConnection()
return wrapper
これにより新しい接続が作成される可能性があるため、現在の接続をDeviceオブジェクトでラップして、変更できるようにする必要があります。これが私のDeviceクラスです(クラスのほとんどは便宜上のものであり、必要なのはconnection
メンバーだけです:
class Device:
def __init__(self):
self.connection = MonkeyRunner.waitForConnection()
self.width = int(self.connection.getProperty('display.width'))
self.height = int(self.connection.getProperty('display.height'))
self.model = self.connection.getProperty('build.model')
def touch(self, x, y, press=MonkeyDevice.DOWN_AND_UP):
self.connection.touch(x, y, press)
デコレータの使用例:
@check_connection
def screenshot(device, filename):
screen = device.connection.takeSnapshot()
screen.writeToFile(filename + '.png', 'png')