Function opentelemetry::trace::mark_span_as_active

#[must_use = "Dropping the guard detaches the context."]pub fn mark_span_as_active<T: Span + Send + Sync>(span: T) -> ContextGuard

Mark a given Span as active.

The Tracer MUST provide a way to update its active Span, and MAY provide convenience methods to manage a Span's lifetime and the scope in which a Span is active. When an active Span is made inactive, the previously-active Span SHOULD be made active. A Span maybe finished (i.e. have a non-null end time) but still be active. A Span may be active on one thread after it has been made inactive on another.

Examples

use opentelemetry::{global, trace::{Span, Tracer}, KeyValue};
use opentelemetry::trace::{get_active_span, mark_span_as_active};

fn my_function() {
    let tracer = global::tracer("my-component-a");
    // start an active span in one function
    let span = tracer.start("span-name");
    let _guard = mark_span_as_active(span);
    // anything happening in functions we call can still access the active span...
    my_other_function();
}

fn my_other_function() {
    // call methods on the current span from
    get_active_span(|span| {
        span.add_event("An event!".to_string(), vec![KeyValue::new("happened", true)]);
    });
}