在线程中调用dbus-python

Question

我在线程中调用dbus方法时遇到段错误.这是我的场景:我有一个程序Service1公开方法测试.第二个程序Service2公开了一个方法公开.由于这个方法做了一些严肃的数值计算,我将一些params从expose传递给正在运行的线程读取器.反过来,该线程在结束其工作时调用Service1的方法测试.我在最后一次dbus调用中发现了段错误.

代码:

# Service1.py
class Service1(Object):
    def __init__(self, bus):
        name = BusName('com.example.Service1', bus)
        path = '/'
       super(Service1, self).__init__(name, path)

    @method(dbus_interface='com.example.Service1',
        in_signature='s', out_signature='s')
    def test(self, test):
        print 'test being called'
        return test

dbus_loop = DBusGMainLoop()
dsession = SessionBus(mainloop=dbus_loop)
loop = gobject.MainLoop()
gobject.threads_init()

im = Service1(dsession)
loop.run()


# Service2.py
dbus_loop = DBusGMainLoop()
dsession = SessionBus(mainloop=dbus_loop)

class Service2(Object):
def __init__(self, bus):
    name = BusName('com.example.Service2', bus)
    super(Service2, self).__init__(name, '/')

    self.queue = Queue()
    self.db = bus.get_object('com.example.Service1', '/')
    self.dbi = dbus.Interface(self.db, dbus_interface='com.example.Service1')

@method(dbus_interface='com.example.Service2',
        in_signature='', out_signature='')
def expose(self):
    print 'calling expose'
    self.queue.put(('params',))

def reader(self):
    while True:
        val = self.queue.get()
        dd = self.dbi.test('test')
        print dd
        self.queue.task_done()


gobject.threads_init()
loop = gobject.MainLoop()

im = Service2(dsession)
reader = threading.Thread(target=im.reader)
reader.start()

loop.run()

要进行测试,请运行Service1.py,Service2.py以及稍后的代码段:

dbus_loop = DBusGMainLoop()
session = SessionBus(mainloop=dbus_loop)
proxy = session.get_object('com.example.Service2', '/')
test_i = dbus.Interface(proxy, dbus_interface='com.example.Service2')
test_i.expose()

运行此代码几次后Service2.py应该崩溃.但为什么？

Answer 1

gobject.threads_init()是不够的,你需要调用dbus.mainloop.glib.threads_init()dbus-glib线程安全.