Avoid magic ret-code integers in the generated callback helpers. The C
trampolines already reference NIMFFI_RET_STALE_WARN; mirror that in the other
two backends: define the canonical NIMFFI_RET_* set once in the C++ header
prelude (guarded so a mixed TU keeps a single definition) and emit module-level
NIMFFI_RET_* consts in the Rust crate, then use the named constants for the
stale-warn, ok, and missing-callback checks instead of 3/0/2.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
nim-ffi never times a handler out: a hard-cancel mid-call into the
underlying library (Waku/libp2p) can leave it half-applied. Instead, while
a request is still in flight its result callback receives a non-terminal
RET_STALE_WARN every StaleWarnInterval (5s default, Android's ANR interval;
-d:ffiStaleWarnIntervalMs to override), carrying the elapsed milliseconds as
a decimal string. The request always ends with exactly one terminal
RET_OK/RET_ERR — the dev decides what to do with a slow one, nim-ffi does
not decide for them.
This replaces the never-released per-proc {.ffi: "timeout = <ms>".} override
and the defaultRequestTimeout context field (issue #93), whose hard abort
unblocked the caller early. The stale-warn interval is an internal context
seam (staleWarnInterval), not a per-proc pragma.
Codegen: emit RET_STALE_WARN in the C/C++ headers, and guard every generated
trampoline (C, C++, Rust, and the Nim abi=c reply trampolines) to early-return
on the non-terminal code so the repeated callback can't double-free the
one-shot reply box. Typed wrappers ignore the progress signal for now; it is
delivered at the raw result-callback boundary.
Closes#126.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
* rust examples: sync main.rs + tokio main.rs demoing the listener API
Adds two bundled examples to the generated Rust crate:
- examples/main.rs: sync flow using std::sync::mpsc to bridge a typed
on_echo_fired listener into main + a wildcard add_event_listener
that uses decode_event_payload::<EchoEvent>(envelope) for the
matching event id.
- examples/tokio_main.rs: same shape via #[tokio::main] +
tokio::sync::mpsc.
Bumps generateCargoToml to ship `[dev-dependencies]` with tokio's
`rt-multi-thread` + `macros` features so the bundled examples can use
#[tokio::main] without polluting the library's runtime profile.
Run with `cargo run --example main` (set DYLD_LIBRARY_PATH=<repo> on
macOS until build.rs emits an rpath).
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
* simplify examples
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Co-authored-by: Claude Opus 4.7 <noreply@anthropic.com>
