tracing-shared-rs

Share a logger between a dylib/cdylib and the main binary

Usage

[dependencies]
tracing-shared = "0.1"

checkout examples/example.rs

cdylib's case

use tracing_shared::SharedLogger;

fn main() {
    let dylib = unsafe { libloading::Library::new(dylib) }.expect("error loading dylib");
    let setup_logger: FnSetupLogger = unsafe { *dylib.get(b"setup_shared_logger_ref").unwrap() };
    let run: FnRun = unsafe { *dylib.get(b"run").unwrap() };
    let logger = SharedLogger::new();
    setup_logger(&logger);
    run("cdylib")
}

dylib's case

use tracing_shared::SharedLogger;

fn main() {
    let logger = SharedLogger::new();
    example_lib::setup_shared_logger_ref(&logger);
    example_lib::run("dylib");
}

Exported entry points

When you expose functions from your shared library so the host binary can dlsym/GetProcAddress them, add #[no_mangle] to keep the symbol names predictable.

#[no_mangle]
pub fn run(src: &str) {
    println!(
        "{} feature = log is enabled: {}",
        src,
        cfg!(feature = "log")
    );
    println!("{} println!", src);
    tracing::info!("{} tracing::info!", src);
    #[cfg(feature = "log")]
    log::info!("{} log::info!", src);
}