| Filename | Latest commit message | Latest commit date |
|---|---|---|
5ab4c627d7
The last pass's only non-comment source change was held by nothing. Reverting the hold's guard so it fires unconditionally survived all five scenarios, because no scenario ever had a call in both states at once: the timeout scenario never arms the hold, and the hold scenarios never let a timeout expire. `holdtimeout` is the missing state. The hold is armed, the runtime is idle, and one poll asks for 150 ms while the hold stays armed for 800. A call the wait woke is the seam's to park; a call whose own timeout expired is on its way out, and parking it would let `holdclose` report the bridge keeping a host call inside the library when what kept it was the fixture. The measurement is which of those two numbers the poll comes back at. Two entries, and the loosening is the one worth reading: the same two conditions in the other order. The hold blocks, so the order is the rule — asked first, it parks the call and then decides whether it should have. Both die on `holdtimeout` at about 800 ms and on nothing else; `holdclose` and `latecall` stay green under both, which is the point. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> |
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| .. | ||
| include | ||
| tests | ||
| CMakeLists.txt | ||
| cultmesh_quic_native.cpp | ||
| README.md | ||
GameCult.Mesh.Quic.Native
One MsQuic body for every CultMesh host that is not .NET: two roles (provider and consumer), two platforms (Windows x64 and Linux x64), and no callbacks across the host boundary.
The bridge owns MsQuic registration, configuration, listener, connection and
stream handles, TLS credential loading, the cultmesh-state-v1 ALPN, the
1-byte-kind plus 4-byte-LE-length QUIC stream framing, and one event queue per
runtime. It owns transport and nothing else: it never decodes a CultMesh frame,
never decides delivery semantics, never coalesces, never reconnects, and in the
v2 path never decides whether to trust a certificate. Frame meaning stays in
GameCult.Mesh and in the TypeScript codec; trust stays with the host.
No host callbacks
Every crossing is the host calling in, including the one blocking wait. MsQuic's worker threads only ever push onto the queue and wake that wait, so no host runtime is called from a thread it does not own. That is what lets one binary serve a Node process through FFI and a Unity player through P/Invoke without either one's threading rules leaking into the other.
It is also why nothing here includes a Node header, a Unity header, or a JavaScript engine: the bridge does not know what is on the other side.
Two ABIs
v2 is the runtime-neutral queue API, and the one new hosts should use. It is
stated once, in include/cultmesh_quic_native.h:
the 64-byte event struct with its field order and asserted offsets, the thirteen
exports with their signatures, the id and return-code conventions, the object
lifetime rules and the threading rules. That file is the contract. This README
does not restate it, and where the two ever disagree the header is right.
A host that can include it should. A host that cannot — koffi, Unity's P/Invoke — declares the same thing in its own FFI and is checked against the header by a test rather than by eye.
Two things worth reading before writing a host, because they are easy to get wrong from the outside:
- Return codes are negative on a bad call, on every platform.
-1is a bad call,-2a rejected argument,<= -1000a MsQuic refusal.QUIC_STATUSitself is not portable — a negative HRESULT on Windows, a positive errno on POSIX — so it never reaches a host;cultmesh_quic_last_statushands over the raw value for diagnostics and nothing else. cultmesh_quic_runtime_closequiesces. It marks the runtime closing, wakes every blockedcultmesh_quic_next_event, and waits for every in-flight call to return before it frees anything. No host call may begin after it starts.
A client connection defers certificate validation: the bridge indicates the
certificate, emits event 3 carrying the DER, and answers MsQuic only when the
host calls cultmesh_quic_connection_certificate_complete. If the host never
answers, MsQuic's 10-second handshake timeout closes the connection and event 4
reports it. Providers load their certificate as PKCS12; the advertised
cert-sha256 pin is computed by the host from that same PKCS12, not here.
v1 is the five exports the shipped Unity package imports by name
(cultmesh_quic_open, _state, _poll, _error, _close). They are Windows
only, matching CultMeshNativeQuicRealtimeTransport.CanConnect, and are
implemented on top of a private v2 runtime holding one connection. They decide
nothing the v2 path does not, with one exception: a v1 connection carries a
SHA-256 pin that is compared here, in C, because that is the contract the
managed connector was built against. A v2 connection never carries one.
Building
Windows x64, from the repo root:
powershell -File scripts/build-quic-native.ps1
MsQuic comes from Microsoft.Native.Quic.MsQuic.OpenSSL 2.5.9, pinned twice: the
NuGet zip by digest and size, and the msquic.dll inside it by digest and size,
because the archive is what the download is checked against and the DLL is what
actually ships beside the bridge. The OpenSSL flavour rather than Schannel
because Schannel's MsQuic refuses QUIC_CREDENTIAL_TYPE_CERTIFICATE_PKCS12,
which is the only credential type a provider has on both platforms.
The build uses MSVC with /Brepro so that a build reproduces itself: the link
timestamps are dropped, and building the same source twice gives the same bytes.
It links the CRT statically (/MT), because a Node or Unity host without the
Visual C++ redistributable cannot load a DLL that imports vcruntime140.dll,
and the failure it reports names no missing runtime; the bridge carries its own.
A rebuild does not reproduce the committed Unity plugin. That plugin
(unity/org.gamecult.cultlib/Runtime/Plugins/x86_64/gamecult_mesh_quic_native.dll,
40,448 bytes) is the older build — before /MT and before the move off
Schannel — and it still imports VCRUNTIME140.dll and MSVCP140.dll. The
current source builds to 302,080 bytes with no CRT import. The committed plugin
stays the older build until the Unity package build runs and replaces it.
Linux x64, on a Debian 13 host:
scripts/build-quic-native.sh
MsQuic comes from Microsoft's Debian 13 pool as a pinned .deb, and the POSIX
headers from the msquic source tree at the matching tag; all four downloads are
verified by SHA-256. The bridge is linked with -fvisibility=hidden so only the
v2 exports leave the .so, and with RPATH $ORIGIN so the libmsquic.so.2
shipped beside it resolves without being installed system-wide.
A Linux host still needs MsQuic's own runtime dependencies present:
libssl3t64, libnuma1, libxdp1, libnl-route-3-200.
The development loop for it is one committed image,
scripts/quic-native-linux-dev.Dockerfile,
pinned to the same debian:13 digest the release workflow builds in. It carries
the toolchain, MsQuic's runtime dependencies, setarch, and Node, because the
mutation harness that drives the runtime-lifetime scenarios is a Node script and
a container that cannot run it cannot check the bridge it just built:
docker build -t cultlib-quic-native-dev -f scripts/quic-native-linux-dev.Dockerfile scripts
docker run --rm --security-opt seccomp=unconfined -v "${PWD}:/src" -w /src cultlib-quic-native-dev bash -lc "scripts/build-quic-native.sh && node scripts/mutate-cultmesh.mjs native"
Both lines are run from the repository root, and the mount is that root wherever
it is: ${PWD} in PowerShell, $(pwd) in a POSIX shell. The second is one line
because the shell it is offered to is not decided here; a continuation would have
to pick one, and a backtick pasted into a POSIX shell is not a continuation.
--security-opt seccomp=unconfined is load-bearing, not caution. The
ThreadSanitizer configuration needs the process's address space where it expects
it, so scripts/mutate-cultmesh.mjs re-executes those runs under setarch -R,
which asks the kernel for personality(ADDR_NO_RANDOMIZE). Docker's default
seccomp profile denies that call. Without it ThreadSanitizer dies before main
with "unexpected memory mapping" — a configuration that never starts, which a
mutation harness would otherwise read as every mutant being killed. The harness
stops with that diagnosis rather than reporting kills it did not earn.
The win32-x64 half of the harness needs the checkout somewhere short — near a drive root rather than under a deep temporary directory. MSVC builds the bridge and its scenario runner through MSBuild, whose file tracker gives out on long paths, and the build then fails for every mutant including the no-op control. The harness stops on a red control rather than reporting a table of kills, so the failure is loud, but it names MSBuild and not the path.
Where an artifact was built is part of what it is. The Linux binary is linked against Debian 13's glibc, so a build from anywhere else is a different artifact whatever the file name says.