From e9b5ea71b3cfe3feef7472f92af5e7f1f442f03b Mon Sep 17 00:00:00 2001
From: Micha Reiser <micha@reiser.io>
Date: Wed, 2 Jul 2025 15:55:37 +0200
Subject: [PATCH] Update Salsa (#19020)

## Summary

This PR updates Salsa to pull in Ibraheem's multithreading improvements (https://github.com/salsa-rs/salsa/pull/921).

## Performance

A small regression for single-threaded benchmarks is expected because
papaya is slightly slower than a `Mutex<FxHashMap>` in the uncontested
case (~10%). However, this shouldn't matter as much in practice because:

1. Salsa has a fast-path when only using 1 DB instance which is the
common case in production. This fast-path is not impacted by the changes
but we measure the slow paths in our benchmarks (because we use multiple
db instances)
2. Fixing the 10x slowdown for the congested case (multi threading)
outweights the downsides of a 10% perf regression for single threaded
use cases, especially considering that ty is heavily multi threaded.

## Test Plan

`cargo test`
---
 Cargo.lock      | 33 +++++++++++++++++++++++++++------
 Cargo.toml      |  2 +-
 fuzz/Cargo.toml |  2 +-
 3 files changed, 29 insertions(+), 8 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 0362914efa..46fa35f15d 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2136,6 +2136,16 @@ version = "0.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b15813163c1d831bf4a13c3610c05c0d03b39feb07f7e09fa234dac9b15aaf39"
 
+[[package]]
+name = "papaya"
+version = "0.2.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f92dd0b07c53a0a0c764db2ace8c541dc47320dad97c2200c2a637ab9dd2328f"
+dependencies = [
+ "equivalent",
+ "seize",
+]
+
 [[package]]
 name = "parking_lot"
 version = "0.12.3"
@@ -3411,8 +3421,8 @@ checksum = "28d3b2b1366ec20994f1fd18c3c594f05c5dd4bc44d8bb0c1c632c8d6829481f"
 
 [[package]]
 name = "salsa"
-version = "0.22.0"
-source = "git+https://github.com/salsa-rs/salsa?rev=0666e2018bc35376b1ac4f98906f2d04d11e5fe4#0666e2018bc35376b1ac4f98906f2d04d11e5fe4"
+version = "0.23.0"
+source = "git+https://github.com/salsa-rs/salsa?rev=fc00eba89e5dcaa5edba51c41aa5f309b5cb126b#fc00eba89e5dcaa5edba51c41aa5f309b5cb126b"
 dependencies = [
  "boxcar",
  "compact_str",
@@ -3422,6 +3432,7 @@ dependencies = [
  "hashlink",
  "indexmap",
  "intrusive-collections",
+ "papaya",
  "parking_lot",
  "portable-atomic",
  "rayon",
@@ -3435,13 +3446,13 @@ dependencies = [
 
 [[package]]
 name = "salsa-macro-rules"
-version = "0.22.0"
-source = "git+https://github.com/salsa-rs/salsa?rev=0666e2018bc35376b1ac4f98906f2d04d11e5fe4#0666e2018bc35376b1ac4f98906f2d04d11e5fe4"
+version = "0.23.0"
+source = "git+https://github.com/salsa-rs/salsa?rev=fc00eba89e5dcaa5edba51c41aa5f309b5cb126b#fc00eba89e5dcaa5edba51c41aa5f309b5cb126b"
 
 [[package]]
 name = "salsa-macros"
-version = "0.22.0"
-source = "git+https://github.com/salsa-rs/salsa?rev=0666e2018bc35376b1ac4f98906f2d04d11e5fe4#0666e2018bc35376b1ac4f98906f2d04d11e5fe4"
+version = "0.23.0"
+source = "git+https://github.com/salsa-rs/salsa?rev=fc00eba89e5dcaa5edba51c41aa5f309b5cb126b#fc00eba89e5dcaa5edba51c41aa5f309b5cb126b"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -3494,6 +3505,16 @@ version = "4.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1c107b6f4780854c8b126e228ea8869f4d7b71260f962fefb57b996b8959ba6b"
 
+[[package]]
+name = "seize"
+version = "0.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e4b8d813387d566f627f3ea1b914c068aac94c40ae27ec43f5f33bde65abefe7"
+dependencies = [
+ "libc",
+ "windows-sys 0.52.0",
+]
+
 [[package]]
 name = "serde"
 version = "1.0.219"
diff --git a/Cargo.toml b/Cargo.toml
index f37c81410b..67548c30e6 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -137,7 +137,7 @@ regex-automata = { version = "0.4.9" }
 rustc-hash = { version = "2.0.0" }
 rustc-stable-hash = { version = "0.1.2" }
 # When updating salsa, make sure to also update the revision in `fuzz/Cargo.toml`
-salsa = { git = "https://github.com/salsa-rs/salsa", rev = "0666e2018bc35376b1ac4f98906f2d04d11e5fe4" }
+salsa = { git = "https://github.com/salsa-rs/salsa", rev = "fc00eba89e5dcaa5edba51c41aa5f309b5cb126b" }
 schemars = { version = "0.8.16" }
 seahash = { version = "4.1.0" }
 serde = { version = "1.0.197", features = ["derive"] }
diff --git a/fuzz/Cargo.toml b/fuzz/Cargo.toml
index 0df27e82b9..e3d0cb63f8 100644
--- a/fuzz/Cargo.toml
+++ b/fuzz/Cargo.toml
@@ -30,7 +30,7 @@ ty_python_semantic = { path = "../crates/ty_python_semantic" }
 ty_vendored = { path = "../crates/ty_vendored" }
 
 libfuzzer-sys = { git = "https://github.com/rust-fuzz/libfuzzer", default-features = false }
-salsa = { git = "https://github.com/salsa-rs/salsa", rev = "0666e2018bc35376b1ac4f98906f2d04d11e5fe4" }
+salsa = { git = "https://github.com/salsa-rs/salsa", rev = "fc00eba89e5dcaa5edba51c41aa5f309b5cb126b" }
 similar = { version = "2.5.0" }
 tracing = { version = "0.1.40" }