tracing-core: Add Dispatch::downgrade() and WeakDispatch
#2293
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jswrenn
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hawkw,
carllerche,
davidbarsky and
a team
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@jswrenn if this won't get merged soon, let's point the PR (or make a separate one) for the |
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why does this need to be pointed at the |
hawkw
reviewed
Sep 7, 2022
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@jswrenn any updates on this? |
Allows collectors and subscribers to stash their own `Dispatch` without causing a memory leak.
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hawkw
requested changes
Sep 20, 2022
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I'd like to get this one merged before cutting another |
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Thanks! I agree with all your suggestions! |
hawkw
approved these changes
Sep 24, 2022
This was creating an `&&'static (dyn Collect + ...)` rather than copying the `&'static (dyn Collect + ...)` into the `WeakDispatch` struct, and the reference to a static reference to a `dyn Collect + ...` doesn't forward trait impls. Removing the `&` un-breaks this.
hawkw
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Sep 24, 2022
Allows `Subscriber`s and `Layer`s to stash their own `Dispatch` without causing a memory leak. ## Motivation Resolves a shortcoming of #2269: that it's impossible for `Subscriber`s or `Layer`s to stash a copy of their own `Dispatch` without creating a reference cycle that would prevent them from being dropped. ## Solution Introduces `WeakDispatch` (analogous to `std::sync::Weak`) that holds a weak pointer to a `Subscriber`. `WeakDispatch` can be created via `Dispatch::downgrade`, and can be transformed into a `Dispatch` via `WeakDispatch::upgrade`. Co-authored-by: Eliza Weisman <[email protected]>
hawkw
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Sep 24, 2022
Allows `Subscriber`s and `Layer`s to stash their own `Dispatch` without causing a memory leak. ## Motivation Resolves a shortcoming of #2269: that it's impossible for `Subscriber`s or `Layer`s to stash a copy of their own `Dispatch` without creating a reference cycle that would prevent them from being dropped. ## Solution Introduces `WeakDispatch` (analogous to `std::sync::Weak`) that holds a weak pointer to a `Subscriber`. `WeakDispatch` can be created via `Dispatch::downgrade`, and can be transformed into a `Dispatch` via `WeakDispatch::upgrade`. Co-authored-by: Eliza Weisman <[email protected]>
hawkw
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Sep 30, 2022
Allows `Subscriber`s and `Layer`s to stash their own `Dispatch` without causing a memory leak. ## Motivation Resolves a shortcoming of #2269: that it's impossible for `Subscriber`s or `Layer`s to stash a copy of their own `Dispatch` without creating a reference cycle that would prevent them from being dropped. ## Solution Introduces `WeakDispatch` (analogous to `std::sync::Weak`) that holds a weak pointer to a `Subscriber`. `WeakDispatch` can be created via `Dispatch::downgrade`, and can be transformed into a `Dispatch` via `WeakDispatch::upgrade`. Co-authored-by: Eliza Weisman <[email protected]>
hawkw
added a commit
that referenced
this pull request
Sep 30, 2022
Allows `Subscriber`s and `Layer`s to stash their own `Dispatch` without causing a memory leak. ## Motivation Resolves a shortcoming of #2269: that it's impossible for `Subscriber`s or `Layer`s to stash a copy of their own `Dispatch` without creating a reference cycle that would prevent them from being dropped. ## Solution Introduces `WeakDispatch` (analogous to `std::sync::Weak`) that holds a weak pointer to a `Subscriber`. `WeakDispatch` can be created via `Dispatch::downgrade`, and can be transformed into a `Dispatch` via `WeakDispatch::upgrade`. Co-authored-by: Eliza Weisman <[email protected]>
hawkw
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Oct 6, 2022
# 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]: #2269 [#2293]: #2293
hawkw
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Oct 6, 2022
# 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]: #2269 [#2293]: #2293
hawkw
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Oct 6, 2022
# 0.1.37 (October 6, 2022) This release of `tracing` incorporates changes from `tracing-core` [v0.1.30][core-0.1.30] and `tracing-attributes` [v0.1.23][0.1.23], including the new `Subscriber::on_register_dispatch` method for performing late initialization after a `Subscriber` is registered as a `Dispatch`, and bugfixes for the `#[instrument]` attribute. Additionally, it fixes instances of the `bare_trait_objects` lint, which is now a warning on `tracing`'s MSRV and will become an error in the next edition. ### Fixed - **attributes**: Incorrect handling of inner attributes in `#[instrument]`ed functions (#2307) - **attributes**: Incorrect location of compiler diagnostic spans generated for type errors in `#[instrument]`ed `async fn`s (#2270) - **attributes**: Updated `syn` dependency to fix compilation with `-Z minimal-versions` (#2246) - `bare_trait_objects` warning in `valueset!` macro expansion (#2308) ### Added - **core**: `Subscriber::on_register_dispatch` method (#2269) - **core**: `WeakDispatch` type and `Dispatch::downgrade()` function (#2293) ### Changed - `tracing-core`: updated to [0.1.30][core-0.1.30] - `tracing-attributes`: updated to [0.1.23][attrs-0.1.23] ### Documented - Added [`tracing-web`] and [`reqwest-tracing`] to related crates (#2283], [#2331) Thanks to new contributors @compiler-errors, @e-nomem, @WorldSEnder, @Xiami2012, and @tl-rodrigo-gryzinski, as well as @jswrenn and @CAD97, for contributing to this release! [core-0.1.30]: https://github.com/tokio-rs/tracing/releases/tag/tracing-core-0.1.30 [attrs-0.1.23]: https://github.com/tokio-rs/tracing/releases/tag/tracing-attributes-0.1.23 [`tracing-web`]: https://crates.io/crates/tracing-web/ [`reqwest-tracing`]: https://crates.io/crates/reqwest-tracing/
hawkw
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Oct 6, 2022
# 0.1.37 (October 6, 2022) This release of `tracing` incorporates changes from `tracing-core` [v0.1.30][core-0.1.30] and `tracing-attributes` [v0.1.23][attrs-0.1.23], including the new `Subscriber::on_register_dispatch` method for performing late initialization after a `Subscriber` is registered as a `Dispatch`, and bugfixes for the `#[instrument]` attribute. Additionally, it fixes instances of the `bare_trait_objects` lint, which is now a warning on `tracing`'s MSRV and will become an error in the next edition. ### Fixed - **attributes**: Incorrect handling of inner attributes in `#[instrument]`ed functions (#2307) - **attributes**: Incorrect location of compiler diagnostic spans generated for type errors in `#[instrument]`ed `async fn`s (#2270) - **attributes**: Updated `syn` dependency to fix compilation with `-Z minimal-versions` (#2246) - `bare_trait_objects` warning in `valueset!` macro expansion (#2308) ### Added - **core**: `Subscriber::on_register_dispatch` method (#2269) - **core**: `WeakDispatch` type and `Dispatch::downgrade()` function (#2293) ### Changed - `tracing-core`: updated to [0.1.30][core-0.1.30] - `tracing-attributes`: updated to [0.1.23][attrs-0.1.23] ### Documented - Added [`tracing-web`] and [`reqwest-tracing`] to related crates (#2283, #2331) Thanks to new contributors @compiler-errors, @e-nomem, @WorldSEnder, @Xiami2012, and @tl-rodrigo-gryzinski, as well as @jswrenn and @CAD97, for contributing to this release! [core-0.1.30]: https://github.com/tokio-rs/tracing/releases/tag/tracing-core-0.1.30 [attrs-0.1.23]: https://github.com/tokio-rs/tracing/releases/tag/tracing-attributes-0.1.23 [`tracing-web`]: https://crates.io/crates/tracing-web/ [`reqwest-tracing`]: https://crates.io/crates/reqwest-tracing/
hawkw
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Oct 6, 2022
)" This reverts commit a0824d3 (PR #2247). As discussed in [this comment][1], the implementation for `Arc`s may cause subtly incorrect behavior if actually used, due to the `&mut self` receiver of the `LookupSpan::register_filter` method, since the `Arc` cannot be mutably borrowed if any clones of it exist. The APIs added in PRs #2269 and #2293 offer an alternative solution to the same problems this change was intended to solve, and --- since this change hasn't been published yet --- it can safely be reverted. [1]: https://giethub.com/tokio-rs/tracing/pull/2247#issuecomment-1199924876
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kaffarell
pushed a commit
to kaffarell/tracing
that referenced
this pull request
May 22, 2024
Allows `Subscriber`s and `Layer`s to stash their own `Dispatch` without causing a memory leak. ## Motivation Resolves a shortcoming of tokio-rs#2269: that it's impossible for `Subscriber`s or `Layer`s to stash a copy of their own `Dispatch` without creating a reference cycle that would prevent them from being dropped. ## Solution Introduces `WeakDispatch` (analogous to `std::sync::Weak`) that holds a weak pointer to a `Subscriber`. `WeakDispatch` can be created via `Dispatch::downgrade`, and can be transformed into a `Dispatch` via `WeakDispatch::upgrade`. Co-authored-by: Eliza Weisman <[email protected]>
kaffarell
pushed a commit
to kaffarell/tracing
that referenced
this pull request
May 22, 2024
# 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 ([tokio-rs#2269]) - `WeakDispatch` type and `Dispatch::downgrade()` function ([tokio-rs#2293]) Thanks to @jswrenn for contributing to this release! [tokio-rs#2269]: tokio-rs#2269 [tokio-rs#2293]: tokio-rs#2293
kaffarell
pushed a commit
to kaffarell/tracing
that referenced
this pull request
May 22, 2024
# 0.1.37 (October 6, 2022) This release of `tracing` incorporates changes from `tracing-core` [v0.1.30][core-0.1.30] and `tracing-attributes` [v0.1.23][attrs-0.1.23], including the new `Subscriber::on_register_dispatch` method for performing late initialization after a `Subscriber` is registered as a `Dispatch`, and bugfixes for the `#[instrument]` attribute. Additionally, it fixes instances of the `bare_trait_objects` lint, which is now a warning on `tracing`'s MSRV and will become an error in the next edition. ### Fixed - **attributes**: Incorrect handling of inner attributes in `#[instrument]`ed functions (tokio-rs#2307) - **attributes**: Incorrect location of compiler diagnostic spans generated for type errors in `#[instrument]`ed `async fn`s (tokio-rs#2270) - **attributes**: Updated `syn` dependency to fix compilation with `-Z minimal-versions` (tokio-rs#2246) - `bare_trait_objects` warning in `valueset!` macro expansion (tokio-rs#2308) ### Added - **core**: `Subscriber::on_register_dispatch` method (tokio-rs#2269) - **core**: `WeakDispatch` type and `Dispatch::downgrade()` function (tokio-rs#2293) ### Changed - `tracing-core`: updated to [0.1.30][core-0.1.30] - `tracing-attributes`: updated to [0.1.23][attrs-0.1.23] ### Documented - Added [`tracing-web`] and [`reqwest-tracing`] to related crates (tokio-rs#2283, tokio-rs#2331) Thanks to new contributors @compiler-errors, @e-nomem, @WorldSEnder, @Xiami2012, and @tl-rodrigo-gryzinski, as well as @jswrenn and @CAD97, for contributing to this release! [core-0.1.30]: https://github.com/tokio-rs/tracing/releases/tag/tracing-core-0.1.30 [attrs-0.1.23]: https://github.com/tokio-rs/tracing/releases/tag/tracing-attributes-0.1.23 [`tracing-web`]: https://crates.io/crates/tracing-web/ [`reqwest-tracing`]: https://crates.io/crates/reqwest-tracing/
kaffarell
pushed a commit
to kaffarell/tracing
that referenced
this pull request
May 22, 2024
…kio-rs#2247)" This reverts commit a0824d3 (PR tokio-rs#2247). As discussed in [this comment][1], the implementation for `Arc`s may cause subtly incorrect behavior if actually used, due to the `&mut self` receiver of the `LookupSpan::register_filter` method, since the `Arc` cannot be mutably borrowed if any clones of it exist. The APIs added in PRs tokio-rs#2269 and tokio-rs#2293 offer an alternative solution to the same problems this change was intended to solve, and --- since this change hasn't been published yet --- it can safely be reverted. [1]: https://giethub.com/tokio-rs/tracing/pull/2247#issuecomment-1199924876
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Allows collectors and subscribers to stash their own
Dispatchwithout causing a memory leak.Motivation
Resolves a shortcoming of #2269: that it's impossible for collectors or subscribers to stash a copy of their own
Dispatchwithout creating a reference cycle that would prevent them from being dropped.Solution
Introduces
WeakDispatch(analogous tostd::sync::Weak) that holds a weak pointer to a collector.WeakDispatchcan be created viaDispatch::downgrade, and can be transformed into aDispatchviaWeakDispatch::upgrade.