Spawn workers on demand

async
Manos Pitsidianakis 2020-06-11 12:01:11 +03:00
parent 40f66f3333
commit bc0189ffa1
Signed by: Manos Pitsidianakis
GPG Key ID: 73627C2F690DF710
1 changed files with 60 additions and 33 deletions

View File

@ -30,6 +30,7 @@ use melib::async_workers::{Work, WorkContext};
use melib::datetime::{self, UnixTimestamp};
use melib::text_processing::Truncate;
use std::collections::HashMap;
use std::sync::atomic::{AtomicUsize, Ordering};
use std::sync::Arc;
use std::sync::Mutex;
use std::thread;
@ -174,6 +175,8 @@ impl WorkController {
};
let queue: WorkQueue = WorkQueue::new(new_jobs_tx, work_context.clone());
let active_threads = Arc::new(AtomicUsize::new(MAX_WORKER));
// Create a SyncFlag to share whether or not there are more jobs to be done.
let (thread_end_tx, thread_end_rx) = bounded(1);
@ -185,13 +188,14 @@ impl WorkController {
let mut threads = threads_lock.lock().unwrap();
/* spawn worker threads */
for thread_num in 0..MAX_WORKER {
for _ in 0..MAX_WORKER {
/* Each worker thread will wait on two channels: thread_end and new_jobs. thread_end
* informs the worker that it should quit and new_jobs informs that there is a new job
* available inside the queue. Only one worker will get each job, and others will
* go back to waiting on the channels */
let thread_queue = queue.clone();
let active_threads = active_threads.clone();
let thread_end_rx = thread_end_rx.clone();
let new_jobs_rx = new_jobs_rx.clone();
let new_jobs_rx = new_jobs_rx.clone();
@ -199,37 +203,14 @@ impl WorkController {
let work_context = work_context.clone();
let pulse = pulse.clone();
let handle = thread::spawn(move || {
let mut work_done = 0;
'work_loop: loop {
debug!("Waiting for work");
select! {
recv(thread_end_rx) -> _ => {
debug!("received thread_end_rx, quitting");
break 'work_loop;
},
recv(new_jobs_rx) -> _ => {
while let Some(work) = thread_queue.get_work() {
debug!("Got some work");
work.compute(work_context.clone());
debug!("finished work");
work_done += 1;
work_context.set_name.send((std::thread::current().id(), "idle-worker".to_string())).unwrap();
work_context.set_status.send((std::thread::current().id(), "inactive".to_string())).unwrap();
pulse.send(ThreadEvent::Pulse).unwrap();
std::thread::yield_now();
}
continue 'work_loop;
},
}
}
/* report the amount of work done. */
debug!("Thread {} did {} jobs.", thread_num, work_done);
});
let handle = spawn_worker(
thread_queue,
active_threads,
thread_end_rx,
new_jobs_rx,
work_context,
pulse,
);
/* add the handle for the newly spawned thread to the list of handles */
threads.insert(handle.thread().id(), String::from("idle-worker").into());
@ -242,7 +223,6 @@ impl WorkController {
let threads_lock = threads_lock.clone();
let _static_threads_lock = static_threads_lock.clone();
let thread_queue = queue.clone();
let threads_lock = threads_lock.clone();
let thread_end_rx = thread_end_rx.clone();
let work_context = work_context.clone();
@ -259,6 +239,19 @@ impl WorkController {
let handle = thread::spawn(move || work.compute(work_context));
_static_threads_lock.lock().unwrap().insert(handle.thread().id(), String::new().into());
} else {
if active_threads.load(Ordering::SeqCst) == 0 {
let handle = spawn_worker(
thread_queue.clone(),
active_threads.clone(),
thread_end_rx.clone(),
new_jobs_rx.clone(),
work_context.clone(),
pulse.clone(),
);
/* add the handle for the newly spawned thread to the list of handles */
threads_lock.lock().unwrap().insert(handle.thread().id(), String::from("idle-worker").into());
}
thread_queue.add_work(work);
}
}
@ -356,3 +349,37 @@ impl WorkController {
self.work_context.clone()
}
}
fn spawn_worker(
thread_queue: WorkQueue,
active_threads: Arc<AtomicUsize>,
thread_end_rx: crossbeam::Receiver<bool>,
new_jobs_rx: crossbeam::Receiver<bool>,
work_context: WorkContext,
pulse: crossbeam::Sender<ThreadEvent>,
) -> std::thread::JoinHandle<()> {
thread::spawn(move || 'work_loop: loop {
debug!("Waiting for work");
select! {
recv(thread_end_rx) -> _ => {
debug!("received thread_end_rx, quitting");
active_threads.fetch_sub(1, Ordering::SeqCst);
break 'work_loop;
},
recv(new_jobs_rx) -> _ => {
active_threads.fetch_sub(1, Ordering::SeqCst);
while let Some(work) = thread_queue.get_work() {
debug!("Got some work");
work.compute(work_context.clone());
debug!("finished work");
work_context.set_name.send((std::thread::current().id(), "idle-worker".to_string())).unwrap();
work_context.set_status.send((std::thread::current().id(), "inactive".to_string())).unwrap();
pulse.send(ThreadEvent::Pulse).unwrap();
std::thread::yield_now();
}
active_threads.fetch_add(1, Ordering::SeqCst);
},
}
})
}