rcore-tutorial/user/src/bin/adder_atomic.rs
2023-01-13 09:59:46 +08:00

72 lines
1.7 KiB
Rust

#![no_std]
#![no_main]
#[macro_use]
extern crate user_lib;
extern crate alloc;
use alloc::vec::Vec;
use core::sync::atomic::{AtomicBool, Ordering};
use user_lib::{exit, get_time, thread_create, waittid, yield_};
static mut A: usize = 0;
static OCCUPIED: AtomicBool = AtomicBool::new(false);
const PER_THREAD_DEFAULT: usize = 10000;
const THREAD_COUNT_DEFAULT: usize = 16;
static mut PER_THREAD: usize = 0;
unsafe fn critical_section(t: &mut usize) {
let a = &mut A as *mut usize;
let cur = a.read_volatile();
for _ in 0..500 {
*t = (*t) * (*t) % 10007;
}
a.write_volatile(cur + 1);
}
fn lock() {
while OCCUPIED
.compare_exchange(false, true, Ordering::Relaxed, Ordering::Relaxed)
.is_err()
{
yield_();
}
}
fn unlock() {
OCCUPIED.store(false, Ordering::Relaxed);
}
unsafe fn f() -> ! {
let mut t = 2usize;
for _ in 0..PER_THREAD {
lock();
critical_section(&mut t);
unlock();
}
exit(t as i32)
}
#[no_mangle]
pub fn main(argc: usize, argv: &[&str]) -> i32 {
let mut thread_count = THREAD_COUNT_DEFAULT;
let mut per_thread = PER_THREAD_DEFAULT;
if argc >= 2 {
thread_count = argv[1].parse().unwrap();
if argc >= 3 {
per_thread = argv[2].parse().unwrap();
}
}
unsafe { PER_THREAD = per_thread; }
let start = get_time();
let mut v = Vec::new();
for _ in 0..thread_count {
v.push(thread_create(f as usize, 0) as usize);
}
for tid in v.into_iter() {
waittid(tid);
}
println!("time cost is {}ms", get_time() - start);
assert_eq!(unsafe { A }, unsafe { PER_THREAD } * thread_count);
0
}