sync: add `watch::Sender::send_modify` method #4310

nylonicious · 2021-12-10T11:21:22Z

send_modify allows to modify inner value without having to allocate new value which can be expensive if the inner value is for example struct that holds a lot of data.

tokio/src/sync/watch.rs

Darksonn · 2021-12-10T11:27:22Z

The CI failure is mio#1539.

tokio/src/sync/watch.rs

tokio/tests/sync_watch.rs

tokio/src/sync/watch.rs

Co-authored-by: Alice Ryhl <alice@ryhl.io>

Darksonn

Hi. Sorry about the delay in reviewing this. Beyond the following comment, then I think this is ready to merge.

tokio/src/sync/watch.rs

nylonicious · 2022-01-10T12:01:34Z

The delay was not a problem, thanks for the review.

virtualritz · 2022-02-22T20:22:58Z

This is exactly what I need.
Case at hand: a realtime system that receives updates, e.g. sensor data, etc. All these are complex structs that contain sometimes dozens of members, sub structs, and containers.
When a single member (or just a few) of such a struct change(s) the channel's value needs to be updated.
But cloning the struct takes too long. In such systems every millisecond counts.

# 1.18.0 (April 27, 2022) This release adds a number of new APIs in `tokio::net`, `tokio::signal`, and `tokio::sync`. In addition, it adds new unstable APIs to `tokio::task` (`Id`s for uniquely identifying a task, and `AbortHandle` for remotely cancelling a task), as well as a number of bugfixes. ### Fixed - blocking: add missing `#[track_caller]` for `spawn_blocking` ([#4616]) - macros: fix `select` macro to process 64 branches ([#4519]) - net: fix `try_io` methods not calling Mio's `try_io` internally ([#4582]) - runtime: recover when OS fails to spawn a new thread ([#4485]) ### Added - macros: support setting a custom crate name for `#[tokio::main]` and `#[tokio::test]` ([#4613]) - net: add `UdpSocket::peer_addr` ([#4611]) - net: add `try_read_buf` method for named pipes ([#4626]) - signal: add `SignalKind` `Hash`/`Eq` impls and `c_int` conversion ([#4540]) - signal: add support for signals up to `SIGRTMAX` ([#4555]) - sync: add `watch::Sender::send_modify` method ([#4310]) - sync: add `broadcast::Receiver::len` method ([#4542]) - sync: add `watch::Receiver::same_channel` method ([#4581]) - sync: implement `Clone` for `RecvError` types ([#4560]) ### Changed - update `nix` to 0.24, limit features ([#4631]) - update `mio` to 0.8.1 ([#4582]) - macros: rename `tokio::select!`'s internal `util` module ([#4543]) - runtime: use `Vec::with_capacity` when building runtime ([#4553]) ### Documented - improve docs for `tokio_unstable` ([#4524]) - runtime: include more documentation for thread_pool/worker ([#4511]) - runtime: update `Handle::current`'s docs to mention `EnterGuard` ([#4567]) - time: clarify platform specific timer resolution ([#4474]) - signal: document that `Signal::recv` is cancel-safe ([#4634]) - sync: `UnboundedReceiver` close docs ([#4548]) ### Unstable The following changes only apply when building with `--cfg tokio_unstable`: - task: add `task::Id` type ([#4630]) - task: add `AbortHandle` type for cancelling tasks in a `JoinSet` ([#4530], [#4640]) - task: fix missing `doc(cfg(...))` attributes for `JoinSet` ([#4531]) - task: fix broken link in `AbortHandle` RustDoc ([#4545]) - metrics: add initial IO driver metrics ([#4507]) [#4616]: #4616 [#4519]: #4519 [#4582]: #4582 [#4485]: #4485 [#4613]: #4613 [#4611]: #4611 [#4626]: #4626 [#4540]: #4540 [#4555]: #4555 [#4310]: #4310 [#4542]: #4542 [#4581]: #4581 [#4560]: #4560 [#4631]: #4631 [#4582]: #4582 [#4543]: #4543 [#4553]: #4553 [#4524]: #4524 [#4511]: #4511 [#4567]: #4567 [#4474]: #4474 [#4634]: #4634 [#4548]: #4548 [#4630]: #4630 [#4530]: #4530 [#4640]: #4640 [#4531]: #4531 [#4545]: #4545 [#4507]: #4507

# 1.18.0 (April 27, 2022) This release adds a number of new APIs in `tokio::net`, `tokio::signal`, and `tokio::sync`. In addition, it adds new unstable APIs to `tokio::task` (`Id`s for uniquely identifying a task, and `AbortHandle` for remotely cancelling a task), as well as a number of bugfixes. ### Fixed - blocking: add missing `#[track_caller]` for `spawn_blocking` ([#4616]) - macros: fix `select` macro to process 64 branches ([#4519]) - net: fix `try_io` methods not calling Mio's `try_io` internally ([#4582]) - runtime: recover when OS fails to spawn a new thread ([#4485]) ### Added - macros: support setting a custom crate name for `#[tokio::main]` and `#[tokio::test]` ([#4613]) - net: add `UdpSocket::peer_addr` ([#4611]) - net: add `try_read_buf` method for named pipes ([#4626]) - signal: add `SignalKind` `Hash`/`Eq` impls and `c_int` conversion ([#4540]) - signal: add support for signals up to `SIGRTMAX` ([#4555]) - sync: add `watch::Sender::send_modify` method ([#4310]) - sync: add `broadcast::Receiver::len` method ([#4542]) - sync: add `watch::Receiver::same_channel` method ([#4581]) - sync: implement `Clone` for `RecvError` types ([#4560]) ### Changed - update `nix` to 0.24, limit features ([#4631]) - update `mio` to 0.8.1 ([#4582]) - macros: rename `tokio::select!`'s internal `util` module ([#4543]) - runtime: use `Vec::with_capacity` when building runtime ([#4553]) ### Documented - improve docs for `tokio_unstable` ([#4524]) - runtime: include more documentation for thread_pool/worker ([#4511]) - runtime: update `Handle::current`'s docs to mention `EnterGuard` ([#4567]) - time: clarify platform specific timer resolution ([#4474]) - signal: document that `Signal::recv` is cancel-safe ([#4634]) - sync: `UnboundedReceiver` close docs ([#4548]) ### Unstable The following changes only apply when building with `--cfg tokio_unstable`: - task: add `task::Id` type ([#4630]) - task: add `AbortHandle` type for cancelling tasks in a `JoinSet` ([#4530], [#4640]) - task: fix missing `doc(cfg(...))` attributes for `JoinSet` ([#4531]) - task: fix broken link in `AbortHandle` RustDoc ([#4545]) - metrics: add initial IO driver metrics ([#4507]) [#4616]: #4616 [#4519]: #4519 [#4582]: #4582 [#4485]: #4485 [#4613]: #4613 [#4611]: #4611 [#4626]: #4626 [#4540]: #4540 [#4555]: #4555 [#4310]: #4310 [#4542]: #4542 [#4581]: #4581 [#4560]: #4560 [#4631]: #4631 [#4582]: #4582 [#4543]: #4543 [#4553]: #4553 [#4524]: #4524 [#4511]: #4511 [#4567]: #4567 [#4474]: #4474 [#4634]: #4634 [#4548]: #4548 [#4630]: #4630 [#4530]: #4530 [#4640]: #4640 [#4531]: #4531 [#4545]: #4545 [#4507]: #4507 Signed-off-by: Eliza Weisman <eliza@buoyant.io>

This PR contains the following updates: | Package | Type | Update | Change | |---|---|---|---| | [tokio](https://tokio.rs) ([source](https://github.com/tokio-rs/tokio)) | dependencies | minor | `1.17.0` -> `1.18.0` | | [tokio](https://tokio.rs) ([source](https://github.com/tokio-rs/tokio)) | dev-dependencies | minor | `1.17.0` -> `1.18.0` | --- ### Release Notes <details> <summary>tokio-rs/tokio</summary> ### [`v1.18.0`](https://github.com/tokio-rs/tokio/releases/tokio-1.18.0) [Compare Source](tokio-rs/tokio@tokio-1.17.0...tokio-1.18.0) ##### 1.18.0 (April 27, 2022) This release adds a number of new APIs in `tokio::net`, `tokio::signal`, and `tokio::sync`. In addition, it adds new unstable APIs to `tokio::task` (`Id`s for uniquely identifying a task, and `AbortHandle` for remotely cancelling a task), as well as a number of bugfixes. ##### Fixed - blocking: add missing `#[track_caller]` for `spawn_blocking` ([#4616](tokio-rs/tokio#4616)) - macros: fix `select` macro to process 64 branches ([#4519](tokio-rs/tokio#4519)) - net: fix `try_io` methods not calling Mio's `try_io` internally ([#4582](tokio-rs/tokio#4582)) - runtime: recover when OS fails to spawn a new thread ([#4485](tokio-rs/tokio#4485)) ##### Added - macros: support setting a custom crate name for `#[tokio::main]` and `#[tokio::test]` ([#4613](tokio-rs/tokio#4613)) - net: add `UdpSocket::peer_addr` ([#4611](tokio-rs/tokio#4611)) - net: add `try_read_buf` method for named pipes ([#4626](tokio-rs/tokio#4626)) - signal: add `SignalKind` `Hash`/`Eq` impls and `c_int` conversion ([#4540](tokio-rs/tokio#4540)) - signal: add support for signals up to `SIGRTMAX` ([#4555](tokio-rs/tokio#4555)) - sync: add `watch::Sender::send_modify` method ([#4310](tokio-rs/tokio#4310)) - sync: add `broadcast::Receiver::len` method ([#4542](tokio-rs/tokio#4542)) - sync: add `watch::Receiver::same_channel` method ([#4581](tokio-rs/tokio#4581)) - sync: implement `Clone` for `RecvError` types ([#4560](tokio-rs/tokio#4560)) ##### Changed - update `mio` to 0.8.1 ([#4582](tokio-rs/tokio#4582)) - macros: rename `tokio::select!`'s internal `util` module ([#4543](tokio-rs/tokio#4543)) - runtime: use `Vec::with_capacity` when building runtime ([#4553](tokio-rs/tokio#4553)) ##### Documented - improve docs for `tokio_unstable` ([#4524](tokio-rs/tokio#4524)) - runtime: include more documentation for thread_pool/worker ([#4511](tokio-rs/tokio#4511)) - runtime: update `Handle::current`'s docs to mention `EnterGuard` ([#4567](tokio-rs/tokio#4567)) - time: clarify platform specific timer resolution ([#4474](tokio-rs/tokio#4474)) - signal: document that `Signal::recv` is cancel-safe ([#4634](tokio-rs/tokio#4634)) - sync: `UnboundedReceiver` close docs ([#4548](tokio-rs/tokio#4548)) ##### Unstable The following changes only apply when building with `--cfg tokio_unstable`: - task: add `task::Id` type ([#4630](tokio-rs/tokio#4630)) - task: add `AbortHandle` type for cancelling tasks in a `JoinSet` ([#4530](tokio-rs/tokio#4530)], \[[#4640](tokio-rs/tokio#4640)) - task: fix missing `doc(cfg(...))` attributes for `JoinSet` ([#4531](tokio-rs/tokio#4531)) - task: fix broken link in `AbortHandle` RustDoc ([#4545](tokio-rs/tokio#4545)) - metrics: add initial IO driver metrics ([#4507](tokio-rs/tokio#4507)) </details> --- ### Configuration 📅 **Schedule**: At any time (no schedule defined). 🚦 **Automerge**: Disabled by config. Please merge this manually once you are satisfied. ♻ **Rebasing**: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox. 🔕 **Ignore**: Close this PR and you won't be reminded about these updates again. --- - [ ] If you want to rebase/retry this PR, click this checkbox. --- This PR has been generated by [Renovate Bot](https://github.com/renovatebot/renovate). Co-authored-by: cabr2-bot <cabr2.help@gmail.com> Reviewed-on: https://codeberg.org/Calciumdibromid/CaBr2/pulls/1327 Reviewed-by: crapStone <crapstone@noreply.codeberg.org> Co-authored-by: Calciumdibromid Bot <cabr2_bot@noreply.codeberg.org> Co-committed-by: Calciumdibromid Bot <cabr2_bot@noreply.codeberg.org>

nylonicious added 2 commits December 10, 2021 12:05

sync: add watch::Sender::send_modify method

d720599

fix typo

e1e73da

github-actions bot added the R-loom Run loom tests on this PR label Dec 10, 2021