Arpad Müller eb0a698adc Make page cache and read_blk async (#5023) ...

## Problem

`read_blk` does I/O and thus we would like to make it async. We can't
make the function async as long as the `PageReadGuard` returned by
`read_blk` isn't `Send`. The page cache is called by `read_blk`, and
thus it can't be async without `read_blk` being async. Thus, we have a
circular dependency.

## Summary of changes

Due to the circular dependency, we convert both the page cache and
`read_blk` to async at the same time:

We make the page cache use `tokio::sync` synchronization primitives as
those are `Send`. This makes all the places that acquire a lock require
async though, which we then also do. This includes also asyncification
of the `read_blk` function.

Builds upon #4994, #5015, #5056, and #5129.

Part of #4743.

2023-08-30 09:04:31 +02:00

..

src

Make page cache and read_blk async (#5023)

2023-08-30 09:04:31 +02:00

Cargo.toml

Preparatory pageserver async conversions (#4773)

2023-07-24 14:01:54 +02:00