Issue with monotonic clocks

[sonhal]

Hi, first thank you for this great project! I am having an issue with a filter targeting wasm32-wasi. When using code like:

std::time::Instant::now() or wasi::clock_time_get(CLOCKID_MONOTONIC, 1_000_000)

I get the following panic:

proxy_1 | [2021-04-25 19:52:37.278][8][critical][wasm] [source/extensions/common/wasm/context.cc:1180] wasm log: panicked at 'calledResult::unwrap()on anErrvalue: Error { code: 58, message: "Not supported, or operation not supported on socket." }', library/std/src/sys/wasi/time.rs:18:10

Seems like monotonic ClockId is not supported in Envoy host environment? Are you aware of this issue and do you know of any solution? I am aware that there is a proxy specific hostcall to get time, but I am depending on Json Web Token libraries that require monotonic clocks.

Example JWT library code for wasi target:

    #[cfg(target_os = "wasi")]
    fn _now() -> u64 {
        use wasi::{clock_time_get, CLOCKID_MONOTONIC};
        let nsec =
            unsafe { clock_time_get(CLOCKID_MONOTONIC, 1_000_000).expect("Clock not available") };
        _nsecs_to_u64(nsec)
    }

[mathetake]

currently only the realtime clock is supported on cpp-host implementation, but it's easy to implement. let me handle this.

[sonhal]

Great! But does that mean I have to wait until the next Envoy release (or compile myself) to get the fix?

[PiotrSikora]

Correct, there is no way to get monotonic clock right now.

[mathetake]

here it is: proxy-wasm/proxy-wasm-cpp-host#156

[jedisct1]

A temporary workaround for this was added to the coarsetime crate.

I'm going to tag a new version shortly, so that people can use code depending on it with the current version of Envoy.

Edit: Done.