HyStart++ implementation [RFC 9406]

[hfstco]

WORK IN PROGRESS

RFC 9406

To avoid big changes in the testbed, prevent problems in currently running research using picoquic and I also want to compare SS, HyStart and HyStart++ for my research, HyStart++ can be enabled as an option. Current HyStart implementation is still the default option.

alg_number:
0 = HyStart disabled (Slow Start)
1 = HyStart enabled (default option)
2 = HyStart++ enabled

./picoquicdemo -H <alg_number>
picoquic_set_default_hystart_algorithm(quic, alg_number)
picoquic_set_hystart_algorithm(cnx, alg_number)

HyStart++ is only implemented into CUBIC currently. I want to implement it for more CC algos and write some test cases before the code is merged into the master branch.

Will update this PR with more information and results.

#1694

[huitema]

I will look at the link failure issue, that should be simple using Visual Studio. Then prepare a PR for your branch.

[hfstco]

I will look at the link failure issue, that should be simple using Visual Studio. Then prepare a PR for your branch.

Thank you! I am not using Windows/Visual Studio and haven't enough time today to fire up my VM.

[huitema]

Seems to be working now. I only had to add hystart_test.c to the picoquictest project.

[huitema]

Question: how do you expect to specify "use of cubic and hystart++" in a run of picoquic_ns?

[hfstco]

Question: how do you expect to specify "use of cubic and hystart++" in a run of picoquic_ns?

I think the best idea is to create an additional variable to st_picoquic_ns_spec_t(e.g. int hystart_algo) and set the default HyStart algorithm in picoquic_ns_create_ctx() for the quic contexts by using picoquic_set_default_hystart_algorithm() or picoquic_set_hystart_algorithm().

Edit: Maybe it is good idea to introduce a enum instead of using an int for hystart_algo.
Edit: Have added an example.