Полностью доведена production-логика AWG2 harness по up2: strict execution, tc parser, anti-torrent, status и документация

traffic_core/src/lock.rs

@@ -1,4 +1,8 @@
-use std::{fs, path::Path};
+use std::{
+    fs::{self, OpenOptions},
+    io::Write,
+    path::Path,
+};
 
 pub struct FileLock {
     path: String,
@@ -10,18 +14,27 @@ impl FileLock {
         if let Some(parent) = p.parent() {
             fs::create_dir_all(parent)?;
         }
-        if p.exists() {
-            let stale = is_stale_lock(p)?;
-            if stale {
-                let _ = fs::remove_file(p);
-            } else {
+        match OpenOptions::new().create_new(true).write(true).open(p) {
+            Ok(mut file) => {
+                file.write_all(std::process::id().to_string().as_bytes())?;
+                return Ok(Self {
+                    path: path.to_string(),
+                });
+            }
+            Err(e) if e.kind() == std::io::ErrorKind::AlreadyExists => {
+                let stale = is_stale_lock(p)?;
+                if stale {
+                    let _ = fs::remove_file(p);
+                    let mut file = OpenOptions::new().create_new(true).write(true).open(p)?;
+                    file.write_all(std::process::id().to_string().as_bytes())?;
+                    return Ok(Self {
+                        path: path.to_string(),
+                    });
+                }
                 anyhow::bail!("lock already exists: {path}");
             }
+            Err(e) => return Err(e.into()),
         }
-        fs::write(p, std::process::id().to_string())?;
-        Ok(Self {
-            path: path.to_string(),
-        })
     }
 }
 
@@ -42,3 +55,15 @@ fn is_stale_lock(path: &Path) -> anyhow::Result<bool> {
     Ok(!Path::new(&proc_path).exists())
 }
 
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn second_acquire_fails_for_live_lock() {
+        let p = format!("/tmp/awg2_harness_lock_test_{}", std::process::id());
+        let _first = FileLock::acquire(&p).expect("first lock");
+        let second = FileLock::acquire(&p);
+        assert!(second.is_err());
+    }
+}