Re:Writing Pythonic Rust
by rmdashrfstar on Monday May 24, 2021 @03:26PM
(#27268625)
Indeed, this blanket advice does not apply in situations where shared resources that require mutable access need to be synchronized. If my async HTTP router is serving two requests that are using the same database client to persist changes, that needs to be synchronized. How does one do this without a mutex?
The lifetime/borrow-checking is the mutex. If you've got a database client that must only be used by one caller at a time, make a function that takes the client as &mut.
Re:Writing Pythonic Rust
by waffletower on Monday May 24, 2021 @04:22PM
(#27269251)
There are STM (Software Transactional Memory) implementations in Rust.
Re:Writing Pythonic Rust
by ibraheemdev on Monday May 24, 2021 @04:02PM
(#27269027)
Use a database pool, although some pool implementations may use mutexes internally.
By acquiring and releasing resources. I’m not intimately familiar with Rust, so I’ll use Go as an example.
Create a one-buffered channel: `make(chan T, 1)`. To acquire, receive from the channel. If the object is in use, the receive will block (goroutine put to sleep) until it’s available. To release, send the acquired object to the channel.
On a language level, no mutexes.
Mutexes aren't an entirely foreign concept to many programmers. Obviously if someone can architect their system in a way that doesn't require Arc<Mutex<_>> then go for it, but we need to be careful about giving blanket advice without alternatives.