nim-ffi/examples/timer

timer example

This example is a self-contained Nimble project demonstrating how to import nim-ffi and use the .ffiCtor. / .ffi. abstraction.

Two ABIs, one library

Every generated library exports two ABIs side by side, and you choose per call site:

ABI	Header / symbols	Use it for
Native (pure C)	<lib>.h / <name>	Same-process / local calls. Flat C structs by value, zero serialization.
CBOR	<lib>_cbor.h / <name>_cbor	Inter-process communication only — a different process or machine, where the request must be serialized to cross the boundary.

In a shared address space the CBOR round-trip is pure overhead, so default to the native ABI locally and reach for CBOR only when you actually cross a process/machine boundary (see ipc/). The per-language examples below: native C (c_bindings/), native Go (go_bindings/), native/CBOR C++ (cpp_bindings/), CBOR Rust (rust_client/), and CBOR-over-socket IPC (ipc/).

Usage

1. Change into the example directory:

   cd examples/timer
   

2. Install the local ffi dependency:

   nimble install -y ../..
   

3. Build the example library:

   nimble build
   

4. Generate bindings:

   nimble genbindings_rust
   nimble genbindings_cpp
   

Rust example clients

The Rust client lives in examples/timer/rust_client.

• Run the sync example:

  cd examples/timer/rust_client
  cargo run --bin rust_client
  

• Run the Tokio example:

  cd examples/timer/rust_client
  cargo run --bin tokio_client
  

C++ example

The generated C++ example lives in examples/timer/cpp_bindings.

Build and run it with:

cd examples/timer/cpp_bindings
cmake -S . -B build
cmake --build build
./build/example