Question about publisher dds_suspend()

[AngelVI13]

Hello, I just want to ask for information on dds_suspend() and dds_resume() functionality for publishers. Is there any plans for the implementation of these features? I looked at the roadmap but was confused if these are covered by some of the bullet points there. Thank you very much in advance and have a lovely day :)

[eboasson]

Hi @AngelVI13 I had completely forgotten about them 😱 Clearly that means I currently have no plans for it, but it can be done fairly easily. Currently it does support batching via a QoS where you explicitly have to flush the batch when you want to be sure it gets sent. That you can set via dds_qset_writer_batching, which ultimately makes it way to whc_batch, which then controls whether data gets sent immediately or not, at:

cyclonedds/src/core/ddsc/src/dds_write.c

Lines 443 to 444 in b475370

	if (!wr->whc_batch)
	ddsi_xpack_send (wr->m_xp, false);

So changing that whc_batch to an int and letting dds_suspend increment it, dds_resume decrement it and calling ddsi_xpack_send send in dds_resume if whc_batch becomes 0 should do it.

If you feel adventurous, do try! I'd be happy to merge a PR that implements it.