在SMACH并发容器的不同状态下使用相同的数据

Question

假设我们有一个并发SMACH容器sm_con，它包括两个状态机SM1和SM2。我需要找到一种方法，让SM1不断地更新一些数据，并使SM2能够访问(并最终修改)相同的数据。我想通过将sm_con的用户数据传递给SM1和SM2作为输入和输出键来解决这个问题，希望如果SM1修改数据，它将自动覆盖_sm_con_s用户数据(有点像使用c++中的指针)，但这不起作用。

相应的代码如下所示：

import smach
import smach_ros
import rospy

class st1(smach.State):
    def __init__(self, outcomes=['successful', 'preempted']):
        smach.State.__init__(self, outcomes, input_keys=['in_test'], output_keys=['out_test'])

    def execute(self, userdata):
        if self.preempt_requested():
            self.service_preempt()
            return 'preempted'
        rospy.logerr('test 1: '+str(userdata.in_test))
        userdata.out_test=userdata.in_test+1
        return 'successful'

class st2(smach.State):
    def __init__(self, outcomes=['successful', 'preempted']):
        smach.State.__init__(self, outcomes, input_keys=['in_test'])

    def execute(self, userdata):
        #time.sleep(2)
        if self.preempt_requested():
            self.service_preempt()
            return 'preempted'
        rospy.logerr('test 2: ' + str(userdata.in_test))
        return 'successful'


if __name__=="__main__":
    rospy.init_node('test_state_machine')

    sm_con = smach.Concurrence(outcomes=['success'],
                               default_outcome='success'
                               )
    sm_con.userdata.testdata = 0
    with sm_con:
        sm_1 = smach.StateMachine(outcomes=['success', 'preempted'], input_keys=['testdata'], output_keys=['testdata'])
        with sm_1:
            smach.StateMachine.add('ST1', st1(),
                                   remapping={'in_test': 'testdata', 'out_test': 'testdata'},
                                   transitions={'successful': 'ST1'})

        sm_2 = smach.StateMachine(outcomes=['success', 'preempted'], input_keys=['testdata'])
        with sm_2:
            smach.StateMachine.add('ST2', st2(),
                                   remapping={'in_test':'testdata'},
                                   transitions={'successful': 'ST2'})

        smach.Concurrence.add('SM1', sm_1)
        smach.Concurrence.add('SM2', sm_2)

    # Execute SMACH plan
    outcome = sm_con.execute()
    print('exit-outcome:' + outcome)
    # Wait for ctrl-c to stop the application
    rospy.spin()

运行此代码，输出“test 1：.”显示在SM1内部，当输出'test 2：.‘时，用户数据会增加。显示当输出保持不变时，SM2不访问递增的数据。

如何在SM1中修改某些数据并访问SM2中的修改数据

Answer 1

我使用描述的这里这样的可变对象找到了解决办法。

应用于上面的代码，如下所示：

import smach
import smach_ros
import rospy

class st1(smach.State):
    def __init__(self, outcomes=['successful', 'preempted']):
        smach.State.__init__(self, outcomes, input_keys=['in_test'])

    def execute(self, userdata):
        if self.preempt_requested():
            self.service_preempt()
            return 'preempted'
        rospy.logerr('test 1: '+str(userdata.in_test))
        userdata.in_test[0]=userdata.in_test[0]+1
        return 'successful'

class st2(smach.State):
    def __init__(self, outcomes=['successful', 'preempted']):
        smach.State.__init__(self, outcomes, input_keys=['in_test'])

    def execute(self, userdata):
        #time.sleep(2)
        if self.preempt_requested():
            self.service_preempt()
            return 'preempted'
        rospy.logerr('test 2: ' + str(userdata.in_test[0]))
        return 'successful'


if __name__=="__main__":
    rospy.init_node('test_state_machine')

    sm_con = smach.Concurrence(outcomes=['success'],
                               default_outcome='success'
                               )
    sm_con.userdata.testdata = [0]
    with sm_con:
        sm_1 = smach.StateMachine(outcomes=['success', 'preempted'], input_keys=['testdata'])
        with sm_1:
            smach.StateMachine.add('ST1', st1(),
                                   remapping={'in_test': 'testdata'},
                                   transitions={'successful': 'ST1'})

        sm_2 = smach.StateMachine(outcomes=['success', 'preempted'], input_keys=['testdata'])
        with sm_2:
            smach.StateMachine.add('ST2', st2(),
                                   remapping={'in_test':'testdata'},
                                   transitions={'successful': 'ST2'})

        smach.Concurrence.add('SM1', sm_1)
        smach.Concurrence.add('SM2', sm_2)

    # Execute SMACH plan
    outcome = sm_con.execute()
    print('exit-outcome:' + outcome)
    # Wait for ctrl-c to stop the application
    rospy.spin()

由于这只是一个解决办法，请参考我相应的问题-post 这里以获得更多信息。