Struct ThreadPool 

pub struct ThreadPool { /* private fields */ }

A collection of threads and a queue for jobs (FnOnce structs) they execute.

Threads stop when they execute a job that panics. If one thread survives, it will recreate all the threads. The next call to schedule or try_schedule also recreates threads.

If your threadpool load is bursty and you want to automatically recover from an all-threads-panicked state, you could use safina_timer to periodically call schedule or try_schedule.

After drop, threads stop as they become idle.

Example

let pool =
    safina_threadpool::ThreadPool::new("worker", 2).unwrap();
let receiver = {
    let (sender, receiver) =
        std::sync::mpsc::channel();
    for data in data_source {
        let sender_clone = sender.clone();
        pool.schedule(
            move || process_data(data, sender_clone));
    }
    receiver
};
let results: Vec<ProcessResult> =
    receiver.iter().collect();
// ...

let pool =
    Arc::new(
        safina_threadpool::ThreadPool::new("worker", 2).unwrap());
let executor = safina_executor::Executor::default();
safina_timer::start_timer_thread();
let pool_clone = pool.clone();
executor.spawn(async move {
    loop {
        safina_timer::sleep_for(Duration::from_millis(500)).await;
        pool_clone.schedule(|| {});
    }
});

Implementations

impl ThreadPool

pub fn new(name: &'static str, size: usize) -> Result<Self, NewThreadPoolError>

Creates a new thread pool containing size threads. The threads all start immediately.

Threads are named with name with a number. For example, ThreadPool::new("worker", 2) creates threads named “worker-1” and “worker-2”. If one of those threads panics, the pool creates “worker-3”.

After the ThreadPool struct drops, the threads continue processing jobs and stop when the queue is empty.

Errors

Returns an error when name is empty, size is zero, or it fails to start the threads.

pub fn size(&self) -> usize

Returns the number of threads in the pool.

pub fn num_live_threads(&self) -> usize

Returns the number of threads currently alive.

pub fn schedule<F: FnOnce() + Send + 'static>(&self, f: F)

Adds a job to the queue. The next idle thread will execute it. Jobs are started in FIFO order.

Blocks when the queue is full or no threads are running. See try_schedule.

Recreates any threads that panicked. Retries on failure to start a new thread.

Puts f in a Box before adding it to the queue.

pub fn try_schedule( &self, f: impl FnOnce() + Send + 'static, ) -> Result<(), TryScheduleError>

Adds a job to the queue and then starts threads to replace any panicked threads. The next idle thread will execute the job. Starts jobs in FIFO order.

Puts f in a Box before adding it to the queue.

Errors

Returns an error when the queue is full or it fails to start a thread. If the return value is not TryScheduleError::QueueFull then it added the job to the queue.

pub fn join(self)

Consumes the thread pool and waits for all threads to stop.

pub fn try_join(self, timeout: Duration) -> Result<(), String>

Consumes the thread pool and waits for all threads to stop.

Errors

Returns an error if the threads do not stop within the timeout duration.

Trait Implementations

impl Debug for ThreadPool

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.