diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:11:28 +0000 |
---|---|---|
committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:11:28 +0000 |
commit | 94a0819fe3a0d679c3042a77bfe6a2afc505daea (patch) | |
tree | 2b827afe6a05f3538db3f7803a88c4587fe85648 /vendor/tracing-core | |
parent | Adding upstream version 1.64.0+dfsg1. (diff) | |
download | rustc-94a0819fe3a0d679c3042a77bfe6a2afc505daea.tar.xz rustc-94a0819fe3a0d679c3042a77bfe6a2afc505daea.zip |
Adding upstream version 1.66.0+dfsg1.upstream/1.66.0+dfsg1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'vendor/tracing-core')
-rw-r--r-- | vendor/tracing-core/.cargo-checksum.json | 2 | ||||
-rw-r--r-- | vendor/tracing-core/CHANGELOG.md | 41 | ||||
-rw-r--r-- | vendor/tracing-core/Cargo.toml | 6 | ||||
-rw-r--r-- | vendor/tracing-core/README.md | 26 | ||||
-rw-r--r-- | vendor/tracing-core/src/callsite.rs | 10 | ||||
-rw-r--r-- | vendor/tracing-core/src/dispatcher.rs | 128 | ||||
-rw-r--r-- | vendor/tracing-core/src/field.rs | 44 | ||||
-rw-r--r-- | vendor/tracing-core/src/metadata.rs | 89 | ||||
-rw-r--r-- | vendor/tracing-core/src/subscriber.rs | 27 |
9 files changed, 326 insertions, 47 deletions
diff --git a/vendor/tracing-core/.cargo-checksum.json b/vendor/tracing-core/.cargo-checksum.json index 157a61ad4..6a9cec13f 100644 --- a/vendor/tracing-core/.cargo-checksum.json +++ b/vendor/tracing-core/.cargo-checksum.json @@ -1 +1 @@ -{"files":{"CHANGELOG.md":"291325b2d5ae0101a9cb9dadfa64810c1c98d04f43c7c1fcee4dc585cb34cf37","Cargo.toml":"d4029f638b3bbb553470ab93080fe78a155db13780e8e52d073d6ca10939614d","LICENSE":"898b1ae9821e98daf8964c8d6c7f61641f5f5aa78ad500020771c0939ee0dea1","README.md":"31f1a3504716da08f771f2fd10e06298a1fd6ecfdc2c78fd1cd66cce693d4e1c","src/callsite.rs":"6a69e08ba8e70234f4ca2a5c6215cdb5ce8d1b0e637102501787169448cbf2a1","src/dispatcher.rs":"5ffade623f3f19a7c497bc72da2d15fcdbd1ab65b1f393c9a9271dd742d99867","src/event.rs":"f2673bf5d266972e567e521c9cd92fb33f28b0c7e010937e3bc2bf9eb483087f","src/field.rs":"ec7f20bdb7a9d79b900777fc444ce82282bdfc4be4afe6223e2b7617da63964d","src/lazy.rs":"318e3558e4446abf26294287167c0788e343044a28072f9217bd985929809087","src/lib.rs":"088b29ecce4bdb5b68df9cbe3984f4b22d7124988866d5aace0e7029ea033d58","src/metadata.rs":"1019ffecd3d8a3636708c6654f34074c041af88b6221c4950037c6bbf09af835","src/parent.rs":"5d5ad733343280a64a1feb6a008e186c39305ec554f14279012b8d7915821471","src/span.rs":"dcf2135e4ca158c1be45007f0be25426c375a4081f8f3c5a4d7f7382d8a950a4","src/spin/LICENSE":"58545fed1565e42d687aecec6897d35c6d37ccb71479a137c0deb2203e125c79","src/spin/mod.rs":"c458ce5e875acb7fbfb279f23254f4924d7c6d6fee419b740800d2e8087d1524","src/spin/mutex.rs":"4d30ff2b59b18fd7909f016e1abdf9aa0c04aa11d047a46e98cffe1319e32dad","src/spin/once.rs":"3781fd4eae0db04d80c03a039906c99b1e01d1583b29ac0144e6fbbd5a0fef0b","src/stdlib.rs":"698693062b8109cace3ffea02e9c2372b7d5b5d43c0b11cb4800b0e7b1a69971","src/subscriber.rs":"916d315ca324a752f70fc3cc557089418a63779ceda54955f55f0ab3c1f3fc7b","tests/common/mod.rs":"0bbb217baa17df0f96cc1ff57dfa74ccc5a959e7f66b15bb7d25d5f43358a278","tests/dispatch.rs":"d3f000fab43734a854c82a7783142910c5e79f806cbd3f8ec5eded598c59ddb1","tests/global_dispatch.rs":"cdc05d77e448ee8b50bfb930abafa3f19b4c6f922b7bebc7797fa1dbdaa1d398","tests/macros.rs":"b1603d888b349c8d103794deceec3b1ae4538b8d3eba805f3f561899e8ad0dd2"},"package":"7b7358be39f2f274f322d2aaed611acc57f382e8eb1e5b48cb9ae30933495ce7"}
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\ No newline at end of file diff --git a/vendor/tracing-core/CHANGELOG.md b/vendor/tracing-core/CHANGELOG.md index c6afcb077..cf0d8e3b9 100644 --- a/vendor/tracing-core/CHANGELOG.md +++ b/vendor/tracing-core/CHANGELOG.md @@ -1,3 +1,44 @@ +# 0.1.30 (October 6, 2022) + +This release of `tracing-core` adds a new `on_register_dispatch` method to the +`Subscriber` trait to allow the `Subscriber` to perform initialization after +being registered as a `Dispatch`, and a `WeakDispatch` type to allow a +`Subscriber` to store its own `Dispatch` without creating reference count +cycles. + +### Added + +- `Subscriber::on_register_dispatch` method ([#2269]) +- `WeakDispatch` type and `Dispatch::downgrade()` function ([#2293]) + +Thanks to @jswrenn for contributing to this release! + +[#2269]: https://github.com/tokio-rs/tracing/pull/2269 +[#2293]: https://github.com/tokio-rs/tracing/pull/2293 + +# 0.1.29 (July 29, 2022) + +This release of `tracing-core` adds `PartialEq` and `Eq` implementations for +metadata types, and improves error messages when setting the global default +subscriber fails. + +### Added + +- `PartialEq` and `Eq` implementations for `Metadata` ([#2229]) +- `PartialEq` and `Eq` implementations for `FieldSet` ([#2229]) + +### Fixed + +- Fixed unhelpful `fmt::Debug` output for `dispatcher::SetGlobalDefaultError` + ([#2250]) +- Fixed compilation with `-Z minimal-versions` ([#2246]) + +Thanks to @jswrenn and @CAD97 for contributing to this release! + +[#2229]: https://github.com/tokio-rs/tracing/pull/2229 +[#2246]: https://github.com/tokio-rs/tracing/pull/2246 +[#2250]: https://github.com/tokio-rs/tracing/pull/2250 + # 0.1.28 (June 23, 2022) This release of `tracing-core` adds new `Value` implementations, including one diff --git a/vendor/tracing-core/Cargo.toml b/vendor/tracing-core/Cargo.toml index 40d797d54..806006141 100644 --- a/vendor/tracing-core/Cargo.toml +++ b/vendor/tracing-core/Cargo.toml @@ -13,7 +13,7 @@ edition = "2018" rust-version = "1.49.0" name = "tracing-core" -version = "0.1.28" +version = "0.1.30" authors = ["Tokio Contributors <team@tokio.rs>"] description = """ Core primitives for application-level tracing. @@ -47,7 +47,7 @@ rustc-args = [ ] [dependencies.once_cell] -version = "1.12" +version = "1.13.0" optional = true [features] @@ -60,7 +60,7 @@ std = ["once_cell"] [target."cfg(tracing_unstable)".dependencies.valuable] version = "0.1.0" optional = true -default_features = false +default-features = false [badges.maintenance] status = "actively-developed" diff --git a/vendor/tracing-core/README.md b/vendor/tracing-core/README.md index f3afec07e..f06c76059 100644 --- a/vendor/tracing-core/README.md +++ b/vendor/tracing-core/README.md @@ -16,9 +16,9 @@ Core primitives for application-level tracing. [Documentation][docs-url] | [Chat][discord-url] [crates-badge]: https://img.shields.io/crates/v/tracing-core.svg -[crates-url]: https://crates.io/crates/tracing-core/0.1.28 +[crates-url]: https://crates.io/crates/tracing-core/0.1.30 [docs-badge]: https://docs.rs/tracing-core/badge.svg -[docs-url]: https://docs.rs/tracing-core/0.1.28 +[docs-url]: https://docs.rs/tracing-core/0.1.30 [docs-master-badge]: https://img.shields.io/badge/docs-master-blue [docs-master-url]: https://tracing-rs.netlify.com/tracing_core [mit-badge]: https://img.shields.io/badge/license-MIT-blue.svg @@ -79,22 +79,22 @@ The following crate feature flags are available: ```toml [dependencies] - tracing-core = { version = "0.1.28", default-features = false } + tracing-core = { version = "0.1.30", default-features = false } ``` **Note**:`tracing-core`'s `no_std` support requires `liballoc`. [`tracing`]: ../tracing -[`span::Id`]: https://docs.rs/tracing-core/0.1.28/tracing_core/span/struct.Id.html -[`Event`]: https://docs.rs/tracing-core/0.1.28/tracing_core/event/struct.Event.html -[`Subscriber`]: https://docs.rs/tracing-core/0.1.28/tracing_core/subscriber/trait.Subscriber.html -[`Metadata`]: https://docs.rs/tracing-core/0.1.28/tracing_core/metadata/struct.Metadata.html -[`Callsite`]: https://docs.rs/tracing-core/0.1.28/tracing_core/callsite/trait.Callsite.html -[`Field`]: https://docs.rs/tracing-core/0.1.28/tracing_core/field/struct.Field.html -[`FieldSet`]: https://docs.rs/tracing-core/0.1.28/tracing_core/field/struct.FieldSet.html -[`Value`]: https://docs.rs/tracing-core/0.1.28/tracing_core/field/trait.Value.html -[`ValueSet`]: https://docs.rs/tracing-core/0.1.28/tracing_core/field/struct.ValueSet.html -[`Dispatch`]: https://docs.rs/tracing-core/0.1.28/tracing_core/dispatcher/struct.Dispatch.html +[`span::Id`]: https://docs.rs/tracing-core/0.1.30/tracing_core/span/struct.Id.html +[`Event`]: https://docs.rs/tracing-core/0.1.30/tracing_core/event/struct.Event.html +[`Subscriber`]: https://docs.rs/tracing-core/0.1.30/tracing_core/subscriber/trait.Subscriber.html +[`Metadata`]: https://docs.rs/tracing-core/0.1.30/tracing_core/metadata/struct.Metadata.html +[`Callsite`]: https://docs.rs/tracing-core/0.1.30/tracing_core/callsite/trait.Callsite.html +[`Field`]: https://docs.rs/tracing-core/0.1.30/tracing_core/field/struct.Field.html +[`FieldSet`]: https://docs.rs/tracing-core/0.1.30/tracing_core/field/struct.FieldSet.html +[`Value`]: https://docs.rs/tracing-core/0.1.30/tracing_core/field/trait.Value.html +[`ValueSet`]: https://docs.rs/tracing-core/0.1.30/tracing_core/field/struct.ValueSet.html +[`Dispatch`]: https://docs.rs/tracing-core/0.1.30/tracing_core/dispatcher/struct.Dispatch.html ## Supported Rust Versions diff --git a/vendor/tracing-core/src/callsite.rs b/vendor/tracing-core/src/callsite.rs index d0fe1a3d6..f88713236 100644 --- a/vendor/tracing-core/src/callsite.rs +++ b/vendor/tracing-core/src/callsite.rs @@ -137,6 +137,15 @@ pub trait Callsite: Sync { /// Returns the [metadata] associated with the callsite. /// + /// <div class="example-wrap" style="display:inline-block"> + /// <pre class="ignore" style="white-space:normal;font:inherit;"> + /// + /// **Note:** Implementations of this method should not produce [`Metadata`] + /// that share the same callsite [`Identifier`] but otherwise differ in any + /// way (e.g., have different `name`s). + /// + /// </pre></div> + /// /// [metadata]: super::metadata::Metadata fn metadata(&self) -> &Metadata<'_>; @@ -478,6 +487,7 @@ impl Callsites { pub(crate) fn register_dispatch(dispatch: &Dispatch) { let dispatchers = DISPATCHERS.register_dispatch(dispatch); + dispatch.subscriber().on_register_dispatch(dispatch); CALLSITES.rebuild_interest(dispatchers); } diff --git a/vendor/tracing-core/src/dispatcher.rs b/vendor/tracing-core/src/dispatcher.rs index 041722c36..36b3cfd85 100644 --- a/vendor/tracing-core/src/dispatcher.rs +++ b/vendor/tracing-core/src/dispatcher.rs @@ -134,7 +134,7 @@ use crate::stdlib::{ fmt, sync::{ atomic::{AtomicBool, AtomicUsize, Ordering}, - Arc, + Arc, Weak, }, }; @@ -142,16 +142,50 @@ use crate::stdlib::{ use crate::stdlib::{ cell::{Cell, RefCell, RefMut}, error, - sync::Weak, }; +#[cfg(feature = "alloc")] +use alloc::sync::{Arc, Weak}; + +#[cfg(feature = "alloc")] +use core::ops::Deref; + /// `Dispatch` trace data to a [`Subscriber`]. -/// #[derive(Clone)] pub struct Dispatch { subscriber: Arc<dyn Subscriber + Send + Sync>, } +/// `WeakDispatch` is a version of [`Dispatch`] that holds a non-owning reference +/// to a [`Subscriber`]. +/// +/// The Subscriber` may be accessed by calling [`WeakDispatch::upgrade`], +/// which returns an `Option<Dispatch>`. If all [`Dispatch`] clones that point +/// at the `Subscriber` have been dropped, [`WeakDispatch::upgrade`] will return +/// `None`. Otherwise, it will return `Some(Dispatch)`. +/// +/// A `WeakDispatch` may be created from a [`Dispatch`] by calling the +/// [`Dispatch::downgrade`] method. The primary use for creating a +/// [`WeakDispatch`] is to allow a Subscriber` to hold a cyclical reference to +/// itself without creating a memory leak. See [here] for details. +/// +/// This type is analogous to the [`std::sync::Weak`] type, but for a +/// [`Dispatch`] rather than an [`Arc`]. +/// +/// [`Arc`]: std::sync::Arc +/// [here]: Subscriber#avoiding-memory-leaks +#[derive(Clone)] +pub struct WeakDispatch { + subscriber: Weak<dyn Subscriber + Send + Sync>, +} + +#[cfg(feature = "alloc")] +#[derive(Clone)] +enum Kind<T> { + Global(&'static (dyn Collect + Send + Sync)), + Scoped(T), +} + #[cfg(feature = "std")] thread_local! { static CURRENT_STATE: State = State { @@ -293,14 +327,21 @@ pub fn has_been_set() -> bool { } /// Returned if setting the global dispatcher fails. -#[derive(Debug)] pub struct SetGlobalDefaultError { _no_construct: (), } +impl fmt::Debug for SetGlobalDefaultError { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_tuple("SetGlobalDefaultError") + .field(&Self::MESSAGE) + .finish() + } +} + impl fmt::Display for SetGlobalDefaultError { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { - f.pad("a global default trace dispatcher has already been set") + f.pad(Self::MESSAGE) } } @@ -308,6 +349,10 @@ impl fmt::Display for SetGlobalDefaultError { #[cfg_attr(docsrs, doc(cfg(feature = "std")))] impl error::Error for SetGlobalDefaultError {} +impl SetGlobalDefaultError { + const MESSAGE: &'static str = "a global default trace dispatcher has already been set"; +} + /// Executes a closure with a reference to this thread's current [dispatcher]. /// /// Note that calls to `get_default` should not be nested; if this function is @@ -419,8 +464,34 @@ impl Dispatch { Registrar(Arc::downgrade(&self.subscriber)) } - /// Registers a new callsite with this subscriber, returning whether or not - /// the subscriber is interested in being notified about the callsite. + /// Creates a [`WeakDispatch`] from this `Dispatch`. + /// + /// A [`WeakDispatch`] is similar to a [`Dispatch`], but it does not prevent + /// the underlying [`Subscriber`] from being dropped. Instead, it only permits + /// access while other references to the `Subscriber` exist. This is equivalent + /// to the standard library's [`Arc::downgrade`] method, but for `Dispatch` + /// rather than `Arc`. + /// + /// The primary use for creating a [`WeakDispatch`] is to allow a `Subscriber` + /// to hold a cyclical reference to itself without creating a memory leak. + /// See [here] for details. + /// + /// [`Arc::downgrade`]: std::sync::Arc::downgrade + /// [here]: Subscriber#avoiding-memory-leaks + pub fn downgrade(&self) -> WeakDispatch { + WeakDispatch { + subscriber: Arc::downgrade(&self.subscriber), + } + } + + #[inline(always)] + #[cfg(not(feature = "alloc"))] + pub(crate) fn subscriber(&self) -> &(dyn Subscriber + Send + Sync) { + &self.subscriber + } + + /// Registers a new callsite with this collector, returning whether or not + /// the collector is interested in being notified about the callsite. /// /// This calls the [`register_callsite`] function on the [`Subscriber`] /// that this `Dispatch` forwards to. @@ -620,14 +691,14 @@ impl Dispatch { /// `T`. #[inline] pub fn is<T: Any>(&self) -> bool { - <dyn Subscriber>::is::<T>(&*self.subscriber) + <dyn Subscriber>::is::<T>(&self.subscriber) } /// Returns some reference to the `Subscriber` this `Dispatch` forwards to /// if it is of type `T`, or `None` if it isn't. #[inline] pub fn downcast_ref<T: Any>(&self) -> Option<&T> { - <dyn Subscriber>::downcast_ref(&*self.subscriber) + <dyn Subscriber>::downcast_ref(&self.subscriber) } } @@ -656,6 +727,45 @@ where } } +// === impl WeakDispatch === + +impl WeakDispatch { + /// Attempts to upgrade this `WeakDispatch` to a [`Dispatch`]. + /// + /// Returns `None` if the referenced `Dispatch` has already been dropped. + /// + /// ## Examples + /// + /// ``` + /// # use tracing_core::subscriber::NoSubscriber; + /// # use tracing_core::dispatcher::Dispatch; + /// let strong = Dispatch::new(NoSubscriber::default()); + /// let weak = strong.downgrade(); + /// + /// // The strong here keeps it alive, so we can still access the object. + /// assert!(weak.upgrade().is_some()); + /// + /// drop(strong); // But not any more. + /// assert!(weak.upgrade().is_none()); + /// ``` + pub fn upgrade(&self) -> Option<Dispatch> { + self.subscriber + .upgrade() + .map(|subscriber| Dispatch { subscriber }) + } +} + +impl fmt::Debug for WeakDispatch { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + let mut tuple = f.debug_tuple("WeakDispatch"); + match self.subscriber.upgrade() { + Some(subscriber) => tuple.field(&format_args!("Some({:p})", subscriber)), + None => tuple.field(&format_args!("None")), + }; + tuple.finish() + } +} + #[cfg(feature = "std")] impl Registrar { pub(crate) fn upgrade(&self) -> Option<Dispatch> { diff --git a/vendor/tracing-core/src/field.rs b/vendor/tracing-core/src/field.rs index c9869ce2c..e103c75a9 100644 --- a/vendor/tracing-core/src/field.rs +++ b/vendor/tracing-core/src/field.rs @@ -145,6 +145,16 @@ pub struct Field { pub struct Empty; /// Describes the fields present on a span. +/// +/// ## Equality +/// +/// In well-behaved applications, two `FieldSet`s [initialized] with equal +/// [callsite identifiers] will have identical fields. Consequently, in release +/// builds, [`FieldSet::eq`] *only* checks that its arguments have equal +/// callsites. However, the equality of field names is checked in debug builds. +/// +/// [initialized]: Self::new +/// [callsite identifiers]: callsite::Identifier pub struct FieldSet { /// The names of each field on the described span. names: &'static [&'static str], @@ -911,6 +921,40 @@ impl fmt::Display for FieldSet { } } +impl Eq for FieldSet {} + +impl PartialEq for FieldSet { + fn eq(&self, other: &Self) -> bool { + if core::ptr::eq(&self, &other) { + true + } else if cfg!(not(debug_assertions)) { + // In a well-behaving application, two `FieldSet`s can be assumed to + // be totally equal so long as they share the same callsite. + self.callsite == other.callsite + } else { + // However, when debug-assertions are enabled, do NOT assume that + // the application is well-behaving; check every the field names of + // each `FieldSet` for equality. + + // `FieldSet` is destructured here to ensure a compile-error if the + // fields of `FieldSet` change. + let Self { + names: lhs_names, + callsite: lhs_callsite, + } = self; + + let Self { + names: rhs_names, + callsite: rhs_callsite, + } = &other; + + // Check callsite equality first, as it is probably cheaper to do + // than str equality. + lhs_callsite == rhs_callsite && lhs_names == rhs_names + } + } +} + // ===== impl Iter ===== impl Iterator for Iter { diff --git a/vendor/tracing-core/src/metadata.rs b/vendor/tracing-core/src/metadata.rs index 47b9388a4..a154419a7 100644 --- a/vendor/tracing-core/src/metadata.rs +++ b/vendor/tracing-core/src/metadata.rs @@ -35,28 +35,25 @@ use crate::stdlib::{ /// _significantly_ lower than that of creating the actual span. Therefore, /// filtering is based on metadata, rather than on the constructed span. /// -/// <pre class="ignore" style="white-space:normal;font:inherit;"> -/// <strong>Note</strong>: Although instances of <code>Metadata</code> -/// cannot be compared directly, they provide a method -/// <a href="struct.Metadata.html#method.id"><code>id</code></a>, returning -/// an opaque <a href="../callsite/struct.Identifier.html">callsite -/// identifier</a>which uniquely identifies the callsite where the metadata -/// originated. This can be used to determine if two <code>Metadata</code> -/// correspond to the same callsite. -/// </pre> +/// ## Equality +/// +/// In well-behaved applications, two `Metadata` with equal +/// [callsite identifiers] will be equal in all other ways (i.e., have the same +/// `name`, `target`, etc.). Consequently, in release builds, [`Metadata::eq`] +/// *only* checks that its arguments have equal callsites. However, the equality +/// of `Metadata`'s other fields is checked in debug builds. /// /// [span]: super::span /// [event]: super::event -/// [name]: Metadata::name() -/// [target]: Metadata::target() -/// [fields]: Metadata::fields() -/// [verbosity level]: Metadata::level() -/// [file name]: Metadata::file() -/// [line number]: Metadata::line() -/// [module path]: Metadata::module_path() +/// [name]: Self::name +/// [target]: Self::target +/// [fields]: Self::fields +/// [verbosity level]: Self::level +/// [file name]: Self::file +/// [line number]: Self::line +/// [module path]: Self::module_path /// [`Subscriber`]: super::subscriber::Subscriber -/// [`id`]: Metadata::id -/// [callsite identifier]: super::callsite::Identifier +/// [callsite identifiers]: Self::callsite pub struct Metadata<'a> { /// The name of the span described by this metadata. name: &'static str, @@ -443,6 +440,62 @@ impl fmt::Debug for Kind { } } +impl<'a> Eq for Metadata<'a> {} + +impl<'a> PartialEq for Metadata<'a> { + #[inline] + fn eq(&self, other: &Self) -> bool { + if core::ptr::eq(&self, &other) { + true + } else if cfg!(not(debug_assertions)) { + // In a well-behaving application, two `Metadata` can be assumed to + // be totally equal so long as they share the same callsite. + self.callsite() == other.callsite() + } else { + // However, when debug-assertions are enabled, do not assume that + // the application is well-behaving; check every field of `Metadata` + // for equality. + + // `Metadata` is destructured here to ensure a compile-error if the + // fields of `Metadata` change. + let Metadata { + name: lhs_name, + target: lhs_target, + level: lhs_level, + module_path: lhs_module_path, + file: lhs_file, + line: lhs_line, + fields: lhs_fields, + kind: lhs_kind, + } = self; + + let Metadata { + name: rhs_name, + target: rhs_target, + level: rhs_level, + module_path: rhs_module_path, + file: rhs_file, + line: rhs_line, + fields: rhs_fields, + kind: rhs_kind, + } = &other; + + // The initial comparison of callsites is purely an optimization; + // it can be removed without affecting the overall semantics of the + // expression. + self.callsite() == other.callsite() + && lhs_name == rhs_name + && lhs_target == rhs_target + && lhs_level == rhs_level + && lhs_module_path == rhs_module_path + && lhs_file == rhs_file + && lhs_line == rhs_line + && lhs_fields == rhs_fields + && lhs_kind == rhs_kind + } + } +} + // ===== impl Level ===== impl Level { diff --git a/vendor/tracing-core/src/subscriber.rs b/vendor/tracing-core/src/subscriber.rs index a6f0834e2..e8f444119 100644 --- a/vendor/tracing-core/src/subscriber.rs +++ b/vendor/tracing-core/src/subscriber.rs @@ -1,5 +1,5 @@ -//! Subscribers collect and record trace data. -use crate::{span, Event, LevelFilter, Metadata}; +//! Collectors collect and record trace data. +use crate::{span, Dispatch, Event, LevelFilter, Metadata}; use crate::stdlib::{ any::{Any, TypeId}, @@ -81,7 +81,28 @@ use crate::stdlib::{ /// [`event`]: Subscriber::event /// [`event_enabled`]: Subscriber::event_enabled pub trait Subscriber: 'static { - // === Span registry methods ============================================== + /// Invoked when this subscriber becomes a [`Dispatch`]. + /// + /// ## Avoiding Memory Leaks + /// + /// `Subscriber`s should not store their own [`Dispatch`]. Because the + /// `Dispatch` owns the `Subscriber`, storing the `Dispatch` within the + /// `Subscriber` will create a reference count cycle, preventing the `Dispatch` + /// from ever being dropped. + /// + /// Instead, when it is necessary to store a cyclical reference to the + /// `Dispatch` within a `Subscriber`, use [`Dispatch::downgrade`] to convert a + /// `Dispatch` into a [`WeakDispatch`]. This type is analogous to + /// [`std::sync::Weak`], and does not create a reference count cycle. A + /// [`WeakDispatch`] can be stored within a `Subscriber` without causing a + /// memory leak, and can be [upgraded] into a `Dispatch` temporarily when + /// the `Dispatch` must be accessed by the `Subscriber`. + /// + /// [`WeakDispatch`]: crate::dispatcher::WeakDispatch + /// [upgraded]: crate::dispatcher::WeakDispatch::upgrade + fn on_register_dispatch(&self, subscriber: &Dispatch) { + let _ = subscriber; + } /// Registers a new [callsite] with this subscriber, returning whether or not /// the subscriber is interested in being notified about the callsite. |