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rospy.sleep doesn't get awaken

asked 2011-11-01 09:29:25 -0500

130s gravatar image

updated 2011-11-01 12:16:33 -0500

Only on one of my machine, this elementary subscribe/publishing tutorial (WritingPublisherSubscriber(python)) doesn't work. In talker.py, thread never returns from rospy.sleep(t) (t can be double number). On my other machine this doesn't happen. Any idea?

Environment:

  • where problem occurs: Ubuntu 11.04, electric, Python 2.7.1+
  • where does not: Ubuntu 10.10, electric, Python 2.6.6

Looking at these diff, I just tried to use python 2.6.6 (by downgrading like this), and found no effect.

Source code (exactly the same with the one in the tutorial page):

#!/usr/bin/env python
import roslib; roslib.load_manifest('beginner_tutorials')
import rospy
from std_msgs.msg import String
def talker():
    pub = rospy.Publisher('chatter', String)
    rospy.init_node('talker')
    while not rospy.is_shutdown():
        str = "hello world %s"%rospy.get_time()
        rospy.loginfo(str)
        pub.publish(String(str))
        rospy.sleep(1.0)
if __name__ == '__main__':
    try:
        talker()
    except rospy.ROSInterruptException: pass

Update) It also occurred when I use C++ version of the same tutorial.

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2 Answers

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answered 2011-11-01 12:19:41 -0500

130s gravatar image

updated 2011-11-01 12:20:10 -0500

Solved - After I reboot OS, this phenomenon has stopped to happen. Still don't know the root cause though...The last time OS was rebooted was for a few days ago and I hibernated it a few times.

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answered 2011-11-01 20:00:42 -0500

Lorenz gravatar image

I suspect that the parameter /use_sim_time was set to True. Maybe you started either stage or gazebo before?

When /use_sim_time is set and no time provider is running, all ROS sleep methods will just block infinitely.

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Comments

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@Lorenz thanks. I'll keep that parameter in mind although now I can't reproduce the phenom. I haven't explicitly turned it on but is there any trigger that could make the parameter on without knowing?
130s gravatar image130s ( 2011-11-02 03:46:19 -0500 )edit

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Asked: 2011-11-01 09:29:25 -0500

Seen: 1,809 times

Last updated: Nov 01 '11