tokio/tokio-trace/tokio-trace-core
Eliza Weisman 46149f031e
trace-core: Fix NoSubscriber causing panics (#975)
PR #973 changed the `tokio_trace_core::span::Id::from_u64` function to
require that the provided `u64` be greater than zero. However, I had
forgotten that the implementation of `Subscriber` for the `NoSubscriber`
type (which is used when no default subscriber is set) always returned
`span::Id::from_u64(0)` from its `new_span` method. In combination with
the assert added in #973, this means that every time a span is hit when
no subscriber is set, `tokio-trace-core` will panic.

This branch fixes the panics by having `NoSubscriber` construct span IDs
using a different (arbitrarily chosen) non-zero constant.

Signed-off-by: Eliza Weisman <eliza@buoyant.io>
2019-03-11 17:08:04 -07:00
..
2019-02-19 12:15:01 -08:00
2019-02-19 12:15:01 -08:00

tokio-trace-core

Core primitives for tokio-trace.

Documentation

Overview

tokio-trace is a framework for instrumenting Rust programs to collect structured, event-based diagnostic information. This crate defines the core primitives of tokio-trace.

The crate provides:

  • Span identifies a span within the execution of a program.

  • Event represents a single event within a trace.

  • Subscriber, the trait implemented to collect trace data.

  • Metadata and Callsite provide information describing Spans.

  • Field, FieldSet, Value, and ValueSet represent the structured data attached to a Span.

  • Dispatch allows span events to be dispatched to Subscribers.

In addition, it defines the global callsite registry and per-thread current dispatcher which other components of the tracing system rely on.

Application authors will typically not use this crate directly. Instead, they will use the tokio-trace crate, which provides a much more fully-featured API. However, this crate's API will change very infrequently, so it may be used when dependencies must be very stable.

License

This project is licensed under the MIT license.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in Tokio by you, shall be licensed as MIT, without any additional terms or conditions.