alloc_observe.Span

1/// A thread-bound tracking token representing an active observation interval.2/// When created while observation is enabled, unsuppressed, and backed by an3/// installed sink, an active span records the current thread parent operation4/// ID, updates the thread current operation ID, increments the active operation5/// count, and captures the sink reference. Active spans must be finished6/// strictly in last-in, first-out order on their originating thread, and each7/// token must be owned and finished by a single authoritative holder. When8/// observation is disabled, suppressed, or running without an installed sink,9/// the token is inert. Concrete field layouts differ between enabled and10/// disabled builds.11pub const Span = if (enabled) EnabledSpan else DisabledSpan;

1/// A thread-bound tracking token representing an active observation interval.2/// When created while observation is enabled, unsuppressed, and backed by an3/// installed sink, an active span records the current thread parent operation4/// ID, updates the thread current operation ID, increments the active operation5/// count, and captures the sink reference. Active spans must be finished6/// strictly in last-in, first-out order on their originating thread, and each7/// token must be owned and finished by a single authoritative holder. When8/// observation is disabled, suppressed, or running without an installed sink,9/// the token is inert. Concrete field layouts differ between enabled and10/// disabled builds.11pub const Span = protocol.Span;