Struct SyncArbiter

pub struct SyncArbiter<A>
where
    A: Actor<Context = SyncContext<A>>,
{ /* private fields */ }

SyncArbiter provides the resources for a single Sync Actor to run on a dedicated thread or threads. This is generally used for CPU bound concurrent workloads. It’s important to note, that the SyncArbiter generates a single address for the pool of hosted Sync Actors. Any message sent to this Address, will be operated on by a single Sync Actor from the pool.

Sync Actors have a different lifecycle compared to Actors on the System Arbiter. For more, see SyncContext.

Examples

use actix::prelude::*;

struct Fibonacci(pub u32);


struct SyncActor;

impl Actor for SyncActor {
    // It's important to note that you use "SyncContext" here instead of "Context".
    type Context = SyncContext<Self>;
}

impl Handler<Fibonacci> for SyncActor {
    type Result = Result<u64, ()>;

    fn handle(&mut self, msg: Fibonacci, _: &mut Self::Context) -> Self::Result {
        if msg.0 == 0 {
            Err(())
        } else if msg.0 == 1 {
            Ok(1)
        } else {
            let mut i = 0;
            let mut sum = 0;
            let mut last = 0;
            let mut curr = 1;
            while i < msg.0 - 1 {
                sum = last + curr;
                last = curr;
                curr = sum;
                i += 1;
            }
            Ok(sum)
        }
    }
}

fn main() {
    System::new().block_on(async {
        // Start the SyncArbiter with 2 threads, and receive the address of the Actor pool.
        let addr = SyncArbiter::start(2, || SyncActor);

        // send 5 messages
        for n in 5..10 {
            // As there are 2 threads, there are at least 2 messages always being processed
            // concurrently by the SyncActor.
            addr.do_send(Fibonacci(n));
        }

    });
}

Implementations

impl<A> SyncArbiter<A>

where A: Actor<Context = SyncContext<A>>,

pub fn start<F>(threads: usize, factory: F) -> Addr<A>

where F: Fn() -> A + Send + Sync + 'static,

Start a new SyncArbiter with specified number of worker threads. Returns a single address of the started actor. A single address is used to communicate to the actor(s), and messages are handled by the next available Actor in the SyncArbiter.

pub fn start_with_thread_builder<F, BF>( threads: usize, thread_builder_factory: BF, factory: F, ) -> Addr<A>

where F: Fn() -> A + Send + Sync + 'static, BF: FnMut() -> Builder,

Start a new SyncArbiter with specified number of worker threads. Each worker thread is spawned from the std::thread::Builder returned by a new call to thread_builder_factory. Returns a single address of the started actor. A single address is used to communicate to the actor(s), and messages are handled by the next available Actor in the SyncArbiter.

Trait Implementations

impl<A> Actor for SyncArbiter<A>

where A: Actor<Context = SyncContext<A>>,

type Context = Context<SyncArbiter<A>>

Actor execution context type

fn started(&mut self, ctx: &mut Self::Context)

Called when an actor gets polled the first time.

fn stopping(&mut self, ctx: &mut Self::Context) -> Running

Called after an actor is in Actor::Stopping state.

fn stopped(&mut self, ctx: &mut Self::Context)

Called after an actor is stopped.

fn start(self) -> Addr<Self>

where Self: Actor<Context = Context<Self>>,

Start a new asynchronous actor, returning its address.

fn start_in_arbiter<F>(wrk: &ArbiterHandle, f: F) -> Addr<Self>

where Self: Actor<Context = Context<Self>>, F: FnOnce(&mut Context<Self>) -> Self + Send + 'static,

Start new actor in arbiter’s thread.

fn create<F>(f: F) -> Addr<Self>

where Self: Actor<Context = Context<Self>>, F: FnOnce(&mut Context<Self>) -> Self,

Start a new asynchronous actor given a Context.