kms: working state

src/backend/kms/session_fd.rs

@@ -0,0 +1,37 @@
+use std::{
+    fmt,
+    rc::Rc,
+    os::unix::io::{RawFd, AsRawFd},
+};
+use smithay::reexports::nix::unistd::close;
+
+#[derive(Clone)]
+pub struct SessionFd(Rc<DropFd>);
+
+struct DropFd(RawFd);
+
+impl SessionFd {
+    pub fn new(fd: RawFd) -> SessionFd {
+        SessionFd(Rc::new(DropFd(fd)))
+    }
+}
+
+impl fmt::Debug for SessionFd {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "Session-provided File Descriptor [{}]", self.0.0)
+    }
+}
+
+impl AsRawFd for SessionFd {
+    fn as_raw_fd(&self) -> RawFd {
+        self.0.0
+    }
+}
+
+impl Drop for DropFd {
+    fn drop(&mut self) {
+        if let Err(err) = close(self.0) {
+            slog_scope::warn!("Failed to close file descriptor {}", self.0);
+        }
+    }
+}