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Carl Fredrik Samson
2020-01-26 20:41:41 +01:00
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book/0_2_naive_implementation.html
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<!DOCTYPE HTML>
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<nav id="sidebar" class="sidebar" aria-label="Table of contents">
<div id="sidebar-scrollbox" class="sidebar-scrollbox">
<ol class="chapter"><li class="expanded "><a href="0_0_introduction.html"><strong aria-hidden="true">1.</strong> Introduction</a></li><li class="expanded "><a href="0_1_background_information.html"><strong aria-hidden="true">2.</strong> Some background information</a></li><li class="expanded "><a href="0_2_naive_implementation.html" class="active"><strong aria-hidden="true">3.</strong> Naive example</a></li><li class="expanded "><a href="0_3_proper_waker.html"><strong aria-hidden="true">4.</strong> Proper Waker</a></li><li class="expanded "><a href="0_4_proper_future.html"><strong aria-hidden="true">5.</strong> Proper Future</a></li><li class="expanded "><a href="0_5_async_wait.html"><strong aria-hidden="true">6.</strong> Supporting async/await</a></li><li class="expanded "><a href="0_6_concurrent_futures.html"><strong aria-hidden="true">7.</strong> Bonus: concurrent futures</a></li></ol>
<div class="sidebar-scrollbox">
<ol class="chapter"><li><a href="0_0_introduction.html"><strong aria-hidden="true">1.</strong> Introduction</a></li><li><a href="0_1_background_information.html"><strong aria-hidden="true">2.</strong> Some background information</a></li><li><ol class="section"><li><a href="0_1_1_trait_objects.html"><strong aria-hidden="true">2.1.</strong> Trait objects and fat pointers</a></li><li><a href="0_1_2_generators_pin.html"><strong aria-hidden="true">2.2.</strong> Generators and Pin</a></li></ol></li><li><a href="0_2_naive_implementation.html" class="active"><strong aria-hidden="true">3.</strong> Naive example</a></li><li><a href="0_3_proper_waker.html"><strong aria-hidden="true">4.</strong> Proper Waker</a></li><li><a href="0_4_proper_future.html"><strong aria-hidden="true">5.</strong> Proper Future</a></li><li><a href="0_5_async_wait.html"><strong aria-hidden="true">6.</strong> Supporting async/await</a></li><li><a href="0_6_concurrent_futures.html"><strong aria-hidden="true">7.</strong> Bonus: concurrent futures</a></li></ol>
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@@ -297,125 +294,125 @@ fn main() {
executor_run(reactor, readylist);
}
<span class="boring">// ====== EXECUTOR ======
</span><span class="boring">fn executor_run(mut reactor: Reactor, rl: Arc&lt;Mutex&lt;Vec&lt;usize&gt;&gt;&gt;) {
</span><span class="boring"> let start = Instant::now();
</span><span class="boring"> loop {
</span><span class="boring"> let mut rl_locked = rl.lock().unwrap();
</span><span class="boring"> while let Some(event) = rl_locked.pop() {
</span><span class="boring"> let dur = (Instant::now() - start).as_secs_f32();
</span><span class="boring"> println!(&quot;Event {} just happened at time: {:.2}.&quot;, event, dur);
</span><span class="boring"> reactor.outstanding.fetch_sub(1, Ordering::Relaxed);
</span><span class="boring"> }
</span><span class="boring"> drop(rl_locked);
</span><span class="boring">
</span><span class="boring"> if reactor.outstanding.load(Ordering::Relaxed) == 0 {
</span><span class="boring"> reactor.close();
</span><span class="boring"> break;
</span><span class="boring"> }
</span><span class="boring">
</span><span class="boring"> thread::park();
</span><span class="boring"> }
</span><span class="boring">}
</span><span class="boring">
</span><span class="boring">// ====== &quot;FUTURE&quot; IMPL ======
</span><span class="boring">#[derive(Debug)]
</span><span class="boring">struct MyWaker {
</span><span class="boring"> id: usize,
</span><span class="boring"> thread: thread::Thread,
</span><span class="boring"> readylist: Arc&lt;Mutex&lt;Vec&lt;usize&gt;&gt;&gt;,
</span><span class="boring">}
</span><span class="boring">
</span><span class="boring">impl MyWaker {
</span><span class="boring"> fn new(id: usize, thread: thread::Thread, readylist: Arc&lt;Mutex&lt;Vec&lt;usize&gt;&gt;&gt;) -&gt; Self {
</span><span class="boring"> MyWaker {
</span><span class="boring"> id,
</span><span class="boring"> thread,
</span><span class="boring"> readylist,
</span><span class="boring"> }
</span><span class="boring"> }
</span><span class="boring">
</span><span class="boring"> fn wake(&amp;self) {
</span><span class="boring"> self.readylist.lock().map(|mut rl| rl.push(self.id)).unwrap();
</span><span class="boring"> self.thread.unpark();
</span><span class="boring"> }
</span><span class="boring">}
</span><span class="boring">
</span><span class="boring">
</span><span class="boring">#[derive(Debug, Clone)]
</span><span class="boring">pub struct Task {
</span><span class="boring"> id: usize,
</span><span class="boring"> pending: bool,
</span><span class="boring">}
</span><span class="boring">
</span><span class="boring">// ===== REACTOR =====
</span><span class="boring">struct Reactor {
</span><span class="boring"> dispatcher: Sender&lt;Event&gt;,
</span><span class="boring"> handle: Option&lt;JoinHandle&lt;()&gt;&gt;,
</span><span class="boring"> outstanding: AtomicUsize,
</span><span class="boring">}
</span><span class="boring">#[derive(Debug)]
</span><span class="boring">enum Event {
</span><span class="boring"> Close,
</span><span class="boring"> Simple(MyWaker, u64),
</span><span class="boring">}
</span><span class="boring">
</span><span class="boring">impl Reactor {
</span><span class="boring"> fn new() -&gt; Self {
</span><span class="boring"> let (tx, rx) = channel::&lt;Event&gt;();
</span><span class="boring"> let mut handles = vec![];
</span><span class="boring"> let handle = thread::spawn(move || {
</span><span class="boring"> // This simulates some I/O resource
</span><span class="boring"> for event in rx {
</span><span class="boring"> match event {
</span><span class="boring"> Event::Close =&gt; break,
</span><span class="boring"> Event::Simple(mywaker, duration) =&gt; {
</span><span class="boring"> let event_handle = thread::spawn(move || {
</span><span class="boring"> thread::sleep(Duration::from_secs(duration));
</span><span class="boring"> mywaker.wake();
</span><span class="boring"> });
</span><span class="boring"> handles.push(event_handle);
</span><span class="boring"> }
</span><span class="boring"> }
</span><span class="boring"> }
</span><span class="boring">
</span><span class="boring"> for handle in handles {
</span><span class="boring"> handle.join().unwrap();
</span><span class="boring"> }
</span><span class="boring"> });
</span><span class="boring">
</span><span class="boring"> Reactor {
</span><span class="boring"> dispatcher: tx,
</span><span class="boring"> handle: Some(handle),
</span><span class="boring"> outstanding: AtomicUsize::new(0),
</span><span class="boring"> }
</span><span class="boring"> }
</span><span class="boring">
</span><span class="boring"> fn register(&amp;mut self, duration: u64, mywaker: MyWaker) {
</span><span class="boring"> self.dispatcher
</span><span class="boring"> .send(Event::Simple(mywaker, duration))
</span><span class="boring"> .unwrap();
</span><span class="boring"> self.outstanding.fetch_add(1, Ordering::Relaxed);
</span><span class="boring"> }
</span><span class="boring">
</span><span class="boring"> fn close(&amp;mut self) {
</span><span class="boring"> self.dispatcher.send(Event::Close).unwrap();
</span><span class="boring"> }
</span><span class="boring">}
</span><span class="boring">
</span><span class="boring">impl Drop for Reactor {
</span><span class="boring"> fn drop(&amp;mut self) {
</span><span class="boring"> self.handle.take().map(|h| h.join().unwrap()).unwrap();
</span><span class="boring"> }
</span><span class="boring">}
</span></code></pre></pre>
# // ====== EXECUTOR ======
# fn executor_run(mut reactor: Reactor, rl: Arc&lt;Mutex&lt;Vec&lt;usize&gt;&gt;&gt;) {
# let start = Instant::now();
# loop {
# let mut rl_locked = rl.lock().unwrap();
# while let Some(event) = rl_locked.pop() {
# let dur = (Instant::now() - start).as_secs_f32();
# println!(&quot;Event {} just happened at time: {:.2}.&quot;, event, dur);
# reactor.outstanding.fetch_sub(1, Ordering::Relaxed);
# }
# drop(rl_locked);
#
# if reactor.outstanding.load(Ordering::Relaxed) == 0 {
# reactor.close();
# break;
# }
#
# thread::park();
# }
# }
#
# // ====== &quot;FUTURE&quot; IMPL ======
# #[derive(Debug)]
# struct MyWaker {
# id: usize,
# thread: thread::Thread,
# readylist: Arc&lt;Mutex&lt;Vec&lt;usize&gt;&gt;&gt;,
# }
#
# impl MyWaker {
# fn new(id: usize, thread: thread::Thread, readylist: Arc&lt;Mutex&lt;Vec&lt;usize&gt;&gt;&gt;) -&gt; Self {
# MyWaker {
# id,
# thread,
# readylist,
# }
# }
#
# fn wake(&amp;self) {
# self.readylist.lock().map(|mut rl| rl.push(self.id)).unwrap();
# self.thread.unpark();
# }
# }
#
#
# #[derive(Debug, Clone)]
# pub struct Task {
# id: usize,
# pending: bool,
# }
#
# // ===== REACTOR =====
# struct Reactor {
# dispatcher: Sender&lt;Event&gt;,
# handle: Option&lt;JoinHandle&lt;()&gt;&gt;,
# outstanding: AtomicUsize,
# }
# #[derive(Debug)]
# enum Event {
# Close,
# Simple(MyWaker, u64),
# }
#
# impl Reactor {
# fn new() -&gt; Self {
# let (tx, rx) = channel::&lt;Event&gt;();
# let mut handles = vec![];
# let handle = thread::spawn(move || {
# // This simulates some I/O resource
# for event in rx {
# match event {
# Event::Close =&gt; break,
# Event::Simple(mywaker, duration) =&gt; {
# let event_handle = thread::spawn(move || {
# thread::sleep(Duration::from_secs(duration));
# mywaker.wake();
# });
# handles.push(event_handle);
# }
# }
# }
#
# for handle in handles {
# handle.join().unwrap();
# }
# });
#
# Reactor {
# dispatcher: tx,
# handle: Some(handle),
# outstanding: AtomicUsize::new(0),
# }
# }
#
# fn register(&amp;mut self, duration: u64, mywaker: MyWaker) {
# self.dispatcher
# .send(Event::Simple(mywaker, duration))
# .unwrap();
# self.outstanding.fetch_add(1, Ordering::Relaxed);
# }
#
# fn close(&amp;mut self) {
# self.dispatcher.send(Event::Close).unwrap();
# }
# }
#
# impl Drop for Reactor {
# fn drop(&amp;mut self) {
# self.handle.take().map(|h| h.join().unwrap()).unwrap();
# }
# }
</code></pre></pre>
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