1 files changed, 54 insertions, 9 deletions

diff --git a/src/rw.rs b/src/rw.rs
index 1f8fa92..96031cc 100644
--- a/src/rw.rs
+++ b/src/rw.rs
@@ -4,6 +4,10 @@ use std::{
     io::{self, PipeReader, PipeWriter, Read, Write},
     os::fd::{AsFd, BorrowedFd},
     process::Stdio,
+    sync::{
+        Arc,
+        atomic::{AtomicBool, Ordering::SeqCst},
+    },
 };
 
 use nix::poll::{PollFd, PollFlags};
@@ -40,6 +44,26 @@ impl From<Output> for Stdio {
     }
 }
 
+impl Input {
+    pub fn try_clone(&self) -> io::Result<Self> {
+        Ok(match self {
+            Input::Stdin => Input::Stdin,
+            Input::Pipe(pr) => Input::Pipe(pr.try_clone()?),
+            Input::File(f) => Input::File(f.try_clone()?),
+        })
+    }
+}
+
+impl Output {
+    pub fn try_clone(&self) -> io::Result<Self> {
+        Ok(match self {
+            Output::Stdout => Output::Stdout,
+            Output::Pipe(pw) => Output::Pipe(pw.try_clone()?),
+            Output::File(f) => Output::File(f.try_clone()?),
+        })
+    }
+}
+
 pub struct Canceler {
     tx: PipeWriter,
 }
@@ -53,7 +77,7 @@ impl Canceler {
 pub struct InputReader {
     input: Input,
     cancel: PipeReader,
-    canceled: bool,
+    canceled: Arc<AtomicBool>,
 }
 
 impl InputReader {
@@ -63,11 +87,22 @@ impl InputReader {
             Self {
                 input,
                 cancel,
-                canceled: false,
+                canceled: Arc::new(AtomicBool::new(false)),
             },
             Canceler { tx },
         )
     }
+
+    pub fn try_clone(&self) -> io::Result<Self> {
+        let input = self.input.try_clone()?;
+        let cancel = self.cancel.try_clone()?;
+        let canceled = self.canceled.clone();
+        Ok(Self {
+            input,
+            cancel,
+            canceled,
+        })
+    }
 }
 
 const TIMEOUT_MS: u16 = 1000;
@@ -79,12 +114,12 @@ enum PollStatus {
 }
 
 fn check<'a>(
-    canceled: &mut bool,
+    canceled: &AtomicBool,
     cancel: &PipeReader,
     fd: BorrowedFd<'a>,
     flags: PollFlags,
 ) -> PollStatus {
-    if *canceled {
+    if canceled.load(SeqCst) {
         return PollStatus::Cancel;
     }
 
@@ -94,13 +129,13 @@ fn check<'a>(
     ];
 
     if nix::poll::poll(&mut poll_fds, TIMEOUT_MS).is_err() {
-        *canceled = true;
+        canceled.store(true, SeqCst);
         return PollStatus::Cancel;
     };
 
     if let Some(event) = poll_fds[0].revents() {
         if event.contains(PollFlags::POLLIN) {
-            *canceled = true;
+            canceled.store(true, SeqCst);
             return PollStatus::Cancel;
         }
     }
@@ -122,7 +157,7 @@ impl InputReader {
             Input::Pipe(pipe) => pipe.as_fd(),
             Input::File(file) => file.as_fd(),
         };
-        check(&mut self.canceled, &self.cancel, read_fd, PollFlags::POLLIN)
+        check(&*self.canceled, &self.cancel, read_fd, PollFlags::POLLIN)
     }
 }
 
@@ -157,7 +192,7 @@ impl Read for InputReader {
 pub struct OutputWriter {
     output: Output,
     cancel: PipeReader,
-    canceled: bool,
+    canceled: Arc<AtomicBool>,
 }
 
 impl OutputWriter {
@@ -167,7 +202,7 @@ impl OutputWriter {
             Self {
                 output,
                 cancel,
-                canceled: false,
+                canceled: Arc::new(AtomicBool::new(false)),
             },
             Canceler { tx },
         )
@@ -186,6 +221,16 @@ impl OutputWriter {
             PollFlags::POLLOUT,
         )
     }
+    pub fn try_clone(&self) -> io::Result<Self> {
+        let output = self.output.try_clone()?;
+        let cancel = self.cancel.try_clone()?;
+        let canceled = self.canceled.clone();
+        Ok(Self {
+            output,
+            cancel,
+            canceled,
+        })
+    }
 }
 
 impl Write for OutputWriter {