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Do topic msg queues allow blocking reads.

asked 2013-09-23 05:45:32 -0500

rnunziata gravatar image

updated 2013-09-23 07:05:57 -0500

Is there support for topic msg queues to allow blocking reads rather then callbacks. I would like to synchronize two queues. Drive one by call back and wait on the other if a msg is not available. How would you sync two independent queues?

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@rnunziata Mark the "check" sign at the answer if you're satisfied with it, instead of "closing".

130s gravatar image 130s  ( 2013-09-24 03:06:49 -0500 )edit

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answered 2013-09-23 17:59:21 -0500

If your question is actually about message synchronization, then please check message_filters.

The TimeSynchronizer filter can subscribe to several topics simultaneously and will call back a single function with messages from all the topics as its arguments. This method will work only when the time stamps of all the messages are exactly same.

To synchronize the messages from sensors that are not synchronized in hardware, e.g. camera and laser, you may need to use ApproximateTime policy.

Regarding message queues you can find some information here: roscpp/Overview/Callbacks and spinning.

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Thanks a lot....still have much to learn

rnunziata gravatar image rnunziata  ( 2013-09-24 02:16:41 -0500 )edit

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Asked: 2013-09-23 05:45:32 -0500

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Last updated: Sep 23 '13