Open fifo twice to have independent file descriptor

So that setting `O_NONBLOCK` would not affect other.

Signed-off-by: Jiahao XU <Jiahao_XU@outlook.com>

src/error.rs

@@ -36,8 +36,6 @@ pub enum FromEnvErrorKind {
     NotAPipe,
     /// Jobserver inheritance is not supported on this platform.
     Unsupported,
-    /// Cannot clone the jobserver fifo fd
-    CannotClone,
 }
 
 impl FromEnvError {
@@ -52,7 +50,6 @@ impl FromEnvError {
             FromEnvErrorInner::NegativeFd(..) => FromEnvErrorKind::NegativeFd,
             FromEnvErrorInner::NotAPipe(..) => FromEnvErrorKind::NotAPipe,
             FromEnvErrorInner::Unsupported => FromEnvErrorKind::Unsupported,
-            FromEnvErrorInner::CannotClone(..) => FromEnvErrorKind::CannotClone,
         }
     }
 }
@@ -69,17 +66,16 @@ impl std::fmt::Display for FromEnvError {
             FromEnvErrorInner::NotAPipe(fd, None) => write!(f, "file descriptor {fd} from the jobserver environment variable value is not a pipe"),
             FromEnvErrorInner::NotAPipe(fd, Some(err)) => write!(f, "file descriptor {fd} from the jobserver environment variable value is not a pipe: {err}"),
             FromEnvErrorInner::Unsupported => write!(f, "jobserver inheritance is not supported on this platform"),
-            FromEnvErrorInner::CannotClone(fd, err) => write!(f, "file descriptor {fd} created fromjobserver environment variable value cannot be cloned: {err}"),
         }
     }
 }
 impl std::error::Error for FromEnvError {
     fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
         match &self.inner {
             FromEnvErrorInner::CannotOpenPath(_, err) => Some(err),
-            FromEnvErrorInner::NotAPipe(_, Some(err))
-            | FromEnvErrorInner::CannotOpenFd(_, err)
-            | FromEnvErrorInner::CannotClone(_, err) => Some(err),
+            FromEnvErrorInner::NotAPipe(_, Some(err)) | FromEnvErrorInner::CannotOpenFd(_, err) => {
+                Some(err)
+            }
             _ => None,
         }
     }
@@ -96,5 +92,4 @@ pub(crate) enum FromEnvErrorInner {
     NegativeFd(RawFd),
     NotAPipe(RawFd, Option<std::io::Error>),
     Unsupported,
-    CannotClone(RawFd, std::io::Error),
 }

src/lib.rs

@@ -644,7 +644,7 @@ mod test {
         client.try_acquire().unwrap().unwrap();
     }
 
-    #[cfg(any(not(unix), linux))]
+    #[cfg(any(windows, target_os = "linux"))]
     #[test]
     fn test_try_acquire() {
         let client = Client::new(0).unwrap();

src/unix.rs

@@ -114,17 +114,17 @@ impl Client {
         })?;
         let path = Path::new(path_str);
 
-        let file = OpenOptions::new()
-            .read(true)
-            .write(true)
-            .open(path)
-            .map_err(|err| FromEnvErrorInner::CannotOpenPath(path_str.to_string(), err))?;
+        let open_file = || {
+            OpenOptions::new()
+                .read(true)
+                .write(true)
+                .open(path)
+                .map_err(|err| FromEnvErrorInner::CannotOpenPath(path_str.to_string(), err))
+        };
 
         Ok(Some(Client {
-            read: file
-                .try_clone()
-                .map_err(|err| FromEnvErrorInner::CannotClone(file.as_raw_fd(), err))?,
-            write: file,
+            read: open_file()?,
+            write: open_file()?,
             creation_arg: ClientCreationArg::Fifo(path.into()),
             is_non_blocking: Some(AtomicBool::new(false)),
         }))