user: add peterson algorithm and Eisenberg & McGuire algorithm

user/src/bin/peterson.rs

@@ -0,0 +1,59 @@
+#![no_std]
+#![no_main]
+#![feature(core_intrinsics)]
+
+#[macro_use]
+extern crate user_lib;
+extern crate alloc;
+extern crate core;
+
+use user_lib::{thread_create, waittid, exit, sleep};
+use alloc::vec::Vec;
+const N: usize = 3;
+
+static mut TURN: usize = 0;
+static mut FLAG: [bool; 2] = [false; 2];
+
+fn peterson_enter_critical(id: usize, peer_id: usize) {
+    println!("Thread {} try enter", id);
+    store!(&FLAG[id], true);
+    store!(&TURN, peer_id);
+    memory_fence!();
+    while load!(&FLAG[peer_id]) && load!(&TURN) == peer_id {
+        println!("Thread {} enter fail", id);
+        sleep(1);
+        println!("Thread {} retry enter", id);
+    }
+    println!("Thread {} enter", id);
+}
+
+fn peterson_exit_critical(id: usize) {
+    store!(&FLAG[id], false);
+    println!("Thread {} exit", id);
+}
+
+pub fn thread_fn(id: usize) -> ! {
+    println!("Thread {} init.", id);
+    let peer_id: usize = id ^ 1;
+    for _ in 0..N {
+        peterson_enter_critical(id, peer_id);
+        for _ in 0..3 {
+            sleep(2);
+        }
+        peterson_exit_critical(id);
+    }
+    exit(0)
+}
+
+#[no_mangle]
+pub fn main() -> i32 {
+    let mut v = Vec::new();
+    v.push(thread_create(thread_fn as usize, 0));
+    v.push(thread_create(thread_fn as usize, 1));
+    for tid in v.iter() {
+        let exit_code = waittid(*tid as usize);
+        println!("thread#{} exited with code {}", tid, exit_code);
+    }
+    println!("main thread exited.");
+    0
+}