RFR: 8370024: HttpClient: QUIC congestion controller doesn't implement pacing [v2]

[Daniel Jeliński]

> Implement pacing for QUIC.
> 
> This is required by RFC 9002. Also, it improves the network utilization on links with long round-trip times.
> 
> The pacing algorithm itself was created based on the suggestions found in RFC 9002, and on the description of the Linux pacing algorithm.
> 
> Pacing is enabled when the round-trip time is less than twice the period at which the selector timeout fires. On Linux the selector timeout fires every millisecond, on Windows it's 15.6 milliseconds by default.
> 
> HttpClient tests came back clean.

Daniel Jeliński has updated the pull request incrementally with one additional commit since the last revision:

  Remove unnecessary object allocation

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/28156/files
  - new: https://git.openjdk.org/jdk/pull/28156/files/dab80e58..2bd6a87c

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=28156&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=28156&range=00-01

  Stats: 3 lines in 1 file changed: 1 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/28156.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/28156/head:pull/28156

PR: https://git.openjdk.org/jdk/pull/28156