Potential Unsound issue in unlock

[CXWorks]

Hi, thanks for your time to read this issue.

Our static analyzer find a potential unsound issue (data races) in ProcessLock, where the unlock fuction needs to be marked as unsafe explicitly, otherwise safe Rust can have data races when user unlock unexpectedly, you can check lock-api for details.

ProcessLock/src/lib.rs

Lines 51 to 54 in 0c53991

	/// 释放进程锁, 通常情况不主动调用, 由LockGuard的生存周期来控制锁的占用周期
	pub fn unlock(&self) -> Result<()> {
	self.0.unlock()
	}

A potentail PoC code is like:

#[deny(unsafe_code)]
use std::sync::Arc;
use process_lock::*;
use std::thread;
use std::time::Duration;


fn main() {
    let mut s1 = Arc::new(ProcessLock::new("test".parse().unwrap(), None).unwrap());
    let mut s2 = s1.clone();
    let h = std::thread::spawn(move || {
        if let Ok(mut guard) = s2.lock() {
            thread::sleep(Duration::from_secs(1));
            // data race 1
        }
    });
    thread::sleep(Duration::from_secs(1));
    if let Ok(_) = s1.unlock(){
      if let Ok(guard2) = s1.lock(){
          println!("data races");
          // data race 2
      }
    }
    h.join().unwrap();
}

Thanks again for your time.