Dining Philosophers example

1 files changed, 68 insertions, 0 deletions

diff --git a/examples/dining_philosophers.rs b/examples/dining_philosophers.rs
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+++ b/examples/dining_philosophers.rs
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+use std::{thread, time::Duration};
+
+use happylock::{LockCollection, Mutex, ThreadKey};
+
+static PHILOSOPHERS: [Philosopher; 5] = [
+	Philosopher {
+		name: "Socrates",
+		left: 0,
+		right: 1,
+	},
+	Philosopher {
+		name: "John Rawls",
+		left: 1,
+		right: 2,
+	},
+	Philosopher {
+		name: "Jeremy Bentham",
+		left: 2,
+		right: 3,
+	},
+	Philosopher {
+		name: "John Stuart Mill",
+		left: 3,
+		right: 4,
+	},
+	Philosopher {
+		name: "Judith Butler",
+		left: 4,
+		right: 0,
+	},
+];
+
+static FORKS: [Mutex<()>; 5] = [
+	Mutex::new(()),
+	Mutex::new(()),
+	Mutex::new(()),
+	Mutex::new(()),
+	Mutex::new(()),
+];
+
+struct Philosopher {
+	name: &'static str,
+	left: usize,
+	right: usize,
+}
+
+impl Philosopher {
+	fn cycle(&self) {
+		let key = ThreadKey::lock().unwrap();
+		thread::sleep(Duration::from_secs(1));
+		let forks = LockCollection::new([&FORKS[self.left], &FORKS[self.right]]).unwrap();
+		let forks = forks.lock(key);
+		println!("{} is eating...", self.name);
+		thread::sleep(Duration::from_secs(1));
+		println!("{} is done eating", self.name);
+		drop(forks);
+	}
+}
+
+fn main() {
+	let handles = PHILOSOPHERS
+		.iter()
+		.map(|philosopher| thread::spawn(move || philosopher.cycle()));
+
+	for handle in handles {
+		_ = handle.join();
+	}
+}