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Ros threading to have multiple processes?

asked 2014-01-21 09:44:38 -0500

Phorce gravatar image

updated 2014-01-28 17:06:33 -0500

ngrennan gravatar image

So basically, what I want to have is this:

1) Have ROS collect data, and process this data into a vector. (This is done)

2) Once the data has been recorded, write the vector to a text file (Not done)

The problem that I have is, how do I stop ros from spinning? How can I then just simply run the function which writes the text to the file?

I've been thinking along the lines of threading, I create a thread that subscribes handles the callback function and another thread that handles writing to the text file. So in essence, the plan would be to have thread1 run for a set amount of time, then halt thread1 and begin to start thread2

Is this possible using ROS? And, is this the only method to solving the above?

Thanks

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Comments

Do you want to do 1) and 2) repeatedly, or just once? In any case try checking out the suggestion by @ahendrix.

demmeln gravatar image demmeln  ( 2014-01-21 11:48:01 -0500 )edit

3 Answers

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answered 2014-01-21 22:19:22 -0500

dornhege gravatar image

If I understand your problem correctly, use ros::spinOnce() to manually spin. Somewhat along the lines of:

while(ros::ok() && !got_all_data) {
    ros::spinOnce();
    loop_rate.sleep();
}

Alternatively if you want to collect all data first and write afterwards, just use ros::spin(); and write the file afterwards. Ctrl-C should stop the spinning. (You might want to test that before doing something critical).

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answered 2014-01-21 10:30:53 -0500

ahendrix gravatar image

Why not record the data you're interested in to a bag file, and then process that bag file later using python bag API?

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0

answered 2014-01-22 00:48:16 -0500

Hamid Didari gravatar image

Hi

I think this Link is helpful for you

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Asked: 2014-01-21 09:44:38 -0500

Seen: 240 times

Last updated: Jan 22 '14