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author | David Sherret <dsherret@users.noreply.github.com> | 2024-06-05 15:17:35 -0400 |
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committer | GitHub <noreply@github.com> | 2024-06-05 15:17:35 -0400 |
commit | 1b355d8a87a3ad43bf240aa66b88eb98c1cd777f (patch) | |
tree | 0422d22a6a0e40873eea4c1ef3eff9d6648f1c51 /cli/npm/managed/cache/value_creator.rs | |
parent | 7ed90a20d04982ae15a52ae2378cbffd4b6839df (diff) |
refactor(npm): improve locking around updating npm resolution (#24104)
Introduces a `SyncReadAsyncWriteLock` to make it harder to write to the
npm resolution without first waiting async in a queue. For the npm
resolution, reading synchronously is fine, but when updating, someone
should wait async, clone the data, then write the data at the end back.
Diffstat (limited to 'cli/npm/managed/cache/value_creator.rs')
-rw-r--r-- | cli/npm/managed/cache/value_creator.rs | 101 |
1 files changed, 0 insertions, 101 deletions
diff --git a/cli/npm/managed/cache/value_creator.rs b/cli/npm/managed/cache/value_creator.rs deleted file mode 100644 index 38801b3aa..000000000 --- a/cli/npm/managed/cache/value_creator.rs +++ /dev/null @@ -1,101 +0,0 @@ -// Copyright 2018-2024 the Deno authors. All rights reserved. MIT license. - -use std::sync::Arc; - -use deno_core::error::AnyError; -use deno_core::futures::future::BoxFuture; -use deno_core::futures::future::LocalBoxFuture; -use deno_core::futures::future::Shared; -use deno_core::futures::FutureExt; -use deno_core::parking_lot::Mutex; -use tokio::task::JoinError; - -// todo(dsherret): unit test this - -type FutureResult<TResult> = Result<TResult, Arc<AnyError>>; -type JoinResult<TResult> = Result<FutureResult<TResult>, Arc<JoinError>>; - -#[derive(Debug)] -struct State<TResult> { - retry_index: usize, - future: Shared<BoxFuture<'static, JoinResult<TResult>>>, -} - -/// Attempts to create a shared value asynchronously on one tokio runtime while -/// many runtimes are requesting the value. -/// -/// This is only useful when the value needs to get created once across -/// many runtimes. -/// -/// This handles the case where one tokio runtime goes down while another -/// one is still running. -#[derive(Debug)] -pub struct MultiRuntimeAsyncValueCreator<TResult: Send + Clone + 'static> { - state: Mutex<State<TResult>>, -} - -impl<TResult: Send + Clone + 'static> MultiRuntimeAsyncValueCreator<TResult> { - pub fn new( - future: LocalBoxFuture<'static, Result<TResult, AnyError>>, - ) -> Self { - Self { - state: Mutex::new(State { - retry_index: 0, - future: Self::create_shared_future(future), - }), - } - } - - pub async fn get( - &self, - recreate_future: impl Fn() -> LocalBoxFuture<'static, Result<TResult, AnyError>>, - ) -> Result<TResult, Arc<AnyError>> { - let (mut future, mut retry_index) = { - let state = self.state.lock(); - (state.future.clone(), state.retry_index) - }; - - loop { - let result = future.await; - - match result { - Ok(result) => return result, - Err(join_error) => { - if join_error.is_cancelled() { - let mut state = self.state.lock(); - - if state.retry_index == retry_index { - // we were the first one to retry, so create a new future - // that we'll run from the current runtime - state.retry_index += 1; - state.future = Self::create_shared_future(recreate_future()); - } - - retry_index = state.retry_index; - future = state.future.clone(); - - // just in case we're stuck in a loop - if retry_index > 1000 { - panic!("Something went wrong.") // should never happen - } - } else { - panic!("{}", join_error); - } - } - } - } - } - - fn create_shared_future( - future: LocalBoxFuture<'static, Result<TResult, AnyError>>, - ) -> Shared<BoxFuture<'static, JoinResult<TResult>>> { - deno_core::unsync::spawn(future) - .map(|result| match result { - Ok(Ok(value)) => Ok(Ok(value)), - Ok(Err(err)) => Ok(Err(Arc::new(err))), - Err(err) => Err(Arc::new(err)), - }) - .boxed() - .shared() - } -} |