# Flume
A blazingly fast multi-producer, single-consumer channel (now with `select` support!).
[](
https://crates.io/crates/flume)
[](
https://docs.rs/flume)
[](
https://github.com/zesterer/flume)
```rust
let (tx, rx) = flume::unbounded();
tx.send(i);
}
});
let received = rx
.iter()
.sum();
assert_eq!((0..10).sum(), received);
```
## Features
- Bounded/unbounded queues
- Senders implement `Send` and may be cloned
- No unsafe code
- Simple design, few dependencies, very fast to compile
- Feature parity with `std::sync::mpsc`
- Support for a `select` interface (see [examples/select.rs])
## Usage
To use Flume, place the following line under the `[dependencies]` section in your `Cargo.toml`:
```
flume = "x.y"
```
## Safety
Flume has no `unsafe` code, so you can be sure that it's not going to leave you with [nasal demons](http://catb.org/jargon/html/N/nasal-demons.html).
## Simplicity
Flume is implemented in just a few hundred lines of code and has very few dependencies. This makes it extremely fast to compile.
## Performance
Flume is considerably faster than `std`'s `mpsc` and often outperforms `crossbeam_channel`.
The following benchmarks were performed on a quad-core (8 logical cores) 2.8 GHz Ryzen 7 CPU running the standard Arch Linux kernel.
```
Create a channel
----------------
create-flume time: [124.53 ns]
create-crossbeam time: [175.76 ns]
create-std time: [47.773 ns] <--- Fastest
Create a channel, then send/recv a single message on it
-------------------------------------------------------
oneshot-flume time: [147.49 ns]
oneshot-crossbeam time: [326.60 ns]
oneshot-std time: [64.348 ns] <--- Fastest
Send/recv single messages on an existing channel
------------------------------------------------
inout-flume time: [18.123 ns] <--- Fastest
inout-crossbeam time: [56.132 ns]
inout-std time: [42.288 ns]
Send 1 message to 32 threads, then send 1 message back from each
------------------------------------------------------------------
hydra-32t-1m-flume time: [98.227 us] <--- Fastest
hydra-32t-1m-crossbeam time: [423.58 us]
hydra-32t-1m-std time: [102.00 us]
Send 1,000 messages to 32 threads, then send 1,000 messages back from each
------------------------------------------------------------------
hydra-32t-1000m-flume time: [1.6267 ms] <--- Fastest
hydra-32t-1000m-crossbeam time: [3.6800 ms]
hydra-32t-1000m-std time: [3.2338 ms]
Send 1,000 messages to 1 thread, then send 1,000 messages back
------------------------------------------------------------------
hydra-1t-1000m-flume time: [89.608 us]
hydra-1t-1000m-crossbeam time: [71.650 us] <--- Fastest
hydra-1t-1000m-std time: [180.53 us]
Send 10,000 messages to 4 threads, then send 10,000 messages back from each
------------------------------------------------------------------
hydra-4t-10000m-flume time: [2.7487 ms] <--- Fastest
hydra-4t-10000m-crossbeam time: [3.2055 ms]
hydra-4t-10000m-std time: [4.8473 ms]
```
## License
Flume is licensed under either of:
- Apache License 2.0, (http://www.apache.org/licenses/LICENSE-2.0)
- MIT license (http://opensource.org/licenses/MIT)