Adds the possibility to keep a strong persistent reference to
a JS object while a `SetImmediate()` call is in effect.

Backport-PR-URL: #18050
PR-URL: #17183
Reviewed-By: James M Snell <[email protected]>
Reviewed-By: Franziska Hinkelmann <[email protected]>
Reviewed-By: Anatoli Papirovski <[email protected]>

Calling into JS land from GC is not allowed, so delay
the resolution of pending pings when a session is destroyed.

Backport-PR-URL: #18050
PR-URL: #17183
Reviewed-By: James M Snell <[email protected]>
Reviewed-By: Franziska Hinkelmann <[email protected]>
Reviewed-By: Anatoli Papirovski <[email protected]>

Introduce an `Http2Scope` class that, when it goes out of scope,
checks whether a write to the network is desired by nghttp2.
If that is the case, schedule a write using `SetImmediate()`
rather than a custom per-session libuv handle.

Backport-PR-URL: #18050
PR-URL: #17183
Reviewed-By: James M Snell <[email protected]>
Reviewed-By: Franziska Hinkelmann <[email protected]>
Reviewed-By: Anatoli Papirovski <[email protected]>

PR-URL: #17406
Reviewed-By: Matteo Collina <[email protected]>
Reviewed-By: Anna Henningsen <[email protected]>
Reviewed-By: Anatoli Papirovski <[email protected]>

Backport-PR-URL: #18050

Backport-PR-URL: #18050
PR-URL: #17406
Reviewed-By: Matteo Collina <[email protected]>
Reviewed-By: Anna Henningsen <[email protected]>
Reviewed-By: Anatoli Papirovski <[email protected]>

This is a significant cleanup and refactoring of the
cleanup/close/destroy logic for Http2Stream and Http2Session.
There are significant changes here in the timing and ordering
of cleanup logic, JS apis. and various related necessary edits.

`nghttp2_stream_write_t` was not a necessary redirection layer
and came with the cost of one additional allocation per stream write.

Also, having both `nghttp2_stream_write` and `nghttp2_stream_write_t`
as identifiers did not help with readability.

Backport-PR-URL: #18050
PR-URL: #17718
Reviewed-By: James M Snell <[email protected]>

- Only finish outgoing `WriteWrap`s once data has actually been
  passed to the underlying socket.
  - This makes HTTP2 streams respect backpressure
- Use `DoTryWrite` as a shortcut for sending out as much of
  the data synchronously without blocking as possible
- Use `NGHTTP2_DATA_FLAG_NO_COPY` to avoid copying DATA frame
  contents into nghttp2’s buffers before sending them out.

Backport-PR-URL: #18050
PR-URL: #17718
Reviewed-By: James M Snell <[email protected]>

Backport-PR-URL: #18050
PR-URL: #17763
Refs: #17746
Reviewed-By: Matteo Collina <[email protected]>

Backport-PR-URL: #18050
PR-URL: #17863
Fixes: #17840
Reviewed-By: Anatoli Papirovski <[email protected]>
Reviewed-By: James M Snell <[email protected]>
Reviewed-By: Colin Ihrig <[email protected]>

Keep a local handle as a reference to the JS `Http2Session`
object so that it will not be garbage collected
when inside an `Http2Scope`, because the presence of the
latter usually indicates that further actions on
the session object are expected.

Strictly speaking, storing the `session_handle_` as a
property on the scope object is not necessary, but
this is not very costly and makes the code more
obviously correct.

Fixes: #17840

Backport-PR-URL: #18050
PR-URL: #17863
Fixes: #17840
Reviewed-By: Anatoli Papirovski <[email protected]>
Reviewed-By: James M Snell <[email protected]>
Reviewed-By: Colin Ihrig <[email protected]>

Backport-PR-URL: #18050
PR-URL: #17620
Reviewed-By: James M Snell <[email protected]>
Reviewed-By: Anna Henningsen <[email protected]>

Backport-PR-URL: #18050
PR-URL: #17939
Reviewed-By: Colin Ihrig <[email protected]>
Reviewed-By: Jon Moss <[email protected]>
Reviewed-By: James M Snell <[email protected]>

Collect and report basic timing information about `Http2Session`
and `Http2Stream` instances.

Backport-PR-URL: #18050
PR-URL: #17906
Refs: #17746
Reviewed-By: Matteo Collina <[email protected]>

Strictly limit the number of concurrent streams based on the
current setting of the MAX_CONCURRENT_STREAMS setting

Backport-PR-URL: #18050
PR-URL: #16766
Reviewed-By: Matteo Collina <[email protected]>
Reviewed-By: Anatoli Papirovski <[email protected]>
Reviewed-By: Sebastiaan Deckers <[email protected]>

Add support for sending and receiving ALTSVC frames.

Backport-PR-URL: #18050
PR-URL: #17917
Reviewed-By: Anna Henningsen <[email protected]>
Reviewed-By: Tiancheng "Timothy" Gu <[email protected]>
Reviewed-By: Matteo Collina <[email protected]>

Backport-PR-URL: #18050
PR-URL: #17935
Reviewed-By: Anatoli Papirovski <[email protected]>
Reviewed-By: Sebastiaan Deckers <[email protected]>
Reviewed-By: Tiancheng "Timothy" Gu <[email protected]>

Add new properties to `Http2Session` to identify alpnProtocol,
and indicator about whether the session is TLS or not, and
initial support for origin set (preparinng for `ORIGIN` frame
support and the client-side `Pool` implementation.

The `originSet` is the set of origins for which an `Http2Session`
may be considered authoritative. Per the `ORIGIN` frame spec,
the originSet is only valid on TLS connections, so this is only
exposed when using a `TLSSocket`.

Backport-PR-URL: #18050
PR-URL: #17935
Reviewed-By: Anatoli Papirovski <[email protected]>
Reviewed-By: Sebastiaan Deckers <[email protected]>
Reviewed-By: Tiancheng "Timothy" Gu <[email protected]>

Add a padding strategy option that makes a best attempt to ensure
that total frame length for DATA and HEADERS frames are aligned
on multiples of 8-bytes.

Backport-PR-URL: #18050
PR-URL: #17938
Reviewed-By: Anna Henningsen <[email protected]>
Reviewed-By: Matteo Collina <[email protected]>

Backport-PR-URL: #18050
PR-URL: #17942
Reviewed-By: Matteo Collina <[email protected]>

Backport-PR-URL: #18050
PR-URL: #17942
Reviewed-By: Matteo Collina <[email protected]>

Backport-PR-URL: #18050
PR-URL: #17954
Reviewed-By: Anatoli Papirovski <[email protected]>
Reviewed-By: James M Snell <[email protected]>
Reviewed-By: Anna Henningsen <[email protected]>

The maxSessionMemory is a cap for the amount of memory an
Http2Session is permitted to consume. If exceeded, new
`Http2Stream` sessions will be rejected with an
`ENHANCE_YOUR_CALM` error and existing `Http2Stream`
instances that are still receiving headers will be
terminated with an `ENHANCE_YOUR_CALM` error.

Backport-PR-URL: #18050
PR-URL: #17967
Reviewed-By: Anna Henningsen <[email protected]>
Reviewed-By: Matteo Collina <[email protected]>

Backport-PR-URL: #18050
PR-URL: #17968
Reviewed-By: Anna Henningsen <[email protected]>

Backport-PR-URL: #18050
PR-URL: #17972
Reviewed-By: Weijia Wang <[email protected]>
Reviewed-By: Jon Moss <[email protected]>
Reviewed-By: Evan Lucas <[email protected]>
Reviewed-By: James M Snell <[email protected]>
Reviewed-By: Luigi Pinca <[email protected]>
Reviewed-By: Colin Ihrig <[email protected]>
Reviewed-By: Ruben Bridgewater <[email protected]>
Reviewed-By: Tobias Nießen <[email protected]>

* verify protections against ping and settings flooding
* Strictly handle and verify handling of unsolicited ping and
  settings frame acks.

Backport-PR-URL: #18050
PR-URL: #17969
Reviewed-By: Anna Henningsen <[email protected]>
Reviewed-By: Anatoli Papirovski <[email protected]>
Reviewed-By: Matteo Collina <[email protected]>

Backport-PR-URL: #18050
PR-URL: #17911
Reviewed-By: James M Snell <[email protected]>
Reviewed-By: Rich Trott <[email protected]>
Reviewed-By: Daniel Bevenius <[email protected]>
Reviewed-By: Luigi Pinca <[email protected]>
Reviewed-By: Gibson Fahnestock <[email protected]>
Reviewed-By: Tobias Nießen <[email protected]>
Reviewed-By: Colin Ihrig <[email protected]>
Reviewed-By: Ruben Bridgewater <[email protected]>
Reviewed-By: Gireesh Punathil <[email protected]>
Reviewed-By: Weijia Wang <[email protected]>

Scheduling a PerformanceGCCallback should not keep the
loop alive but due to the recent switch to using the
native SetImmediate method, it does. Go back to using
uv_async_t and add a regression test.

Backport-PR-URL: #18050
PR-URL: #18051
Fixes: #18047
Refs: #18020
Reviewed-By: James M Snell <[email protected]>
Reviewed-By: Anna Henningsen <[email protected]>

Introduce an `Http2Scope` class that, when it goes out of scope,
checks whether a write to the network is desired by nghttp2.
If that is the case, schedule a write using `SetImmediate()`
rather than a custom per-session libuv handle.

Backport-PR-URL: nodejs#18050
PR-URL: nodejs#17183
Reviewed-By: James M Snell <[email protected]>
Reviewed-By: Franziska Hinkelmann <[email protected]>
Reviewed-By: Anatoli Papirovski <[email protected]>