Created
July 17, 2022 12:50
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| use std::io::Write; | |
| use std::sync::atomic::{self, AtomicU8}; | |
| use std::sync::Arc; | |
| use std::thread::{self}; | |
| struct SpinLock { | |
| flag: AtomicU8, | |
| } | |
| impl SpinLock { | |
| pub fn new() -> Self { | |
| SpinLock { | |
| flag: AtomicU8::new(0), | |
| } | |
| } | |
| pub fn lock(&self) { | |
| loop { | |
| match self.flag.compare_exchange_weak( | |
| 0, | |
| 1, | |
| atomic::Ordering::AcqRel, | |
| atomic::Ordering::Relaxed, | |
| ) { | |
| Ok(v) => { | |
| assert_eq!(v, 0); | |
| break; | |
| } | |
| Err(v) => { | |
| assert_eq!(v, 1); | |
| continue; | |
| } | |
| } | |
| } | |
| } | |
| pub fn unlock(&self) { | |
| self.flag.store(0, atomic::Ordering::Release); | |
| } | |
| } | |
| fn main() { | |
| let lock = Arc::new(SpinLock::new()); | |
| let a_lock = lock.clone(); | |
| let a = thread::spawn(move || { | |
| a_lock.lock(); | |
| for i in 0..10 { | |
| thread::sleep(std::time::Duration::from_millis(100)); | |
| print!("{} ", i); | |
| _ = std::io::stdout().flush(); | |
| } | |
| a_lock.unlock(); | |
| }); | |
| let b_lock = lock.clone(); | |
| let b = thread::spawn(move || { | |
| b_lock.lock(); | |
| for i in 10..20 { | |
| thread::sleep(std::time::Duration::from_millis(100)); | |
| print!("{} ", i); | |
| _ = std::io::stdout().flush(); | |
| } | |
| b_lock.unlock(); | |
| }); | |
| _ = a.join(); | |
| _ = b.join(); | |
| } |
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