Handle EINTR retry in os.write() (PEP 475)

youknowone · youknowone · commit 301b4d6c7798 · 2026-03-23T14:38:15.000+09:00
Add EINTR retry loop to os.write(), matching the existing
pattern in os.read() and os.readinto(). Remove the
expectedFailure marker from test_write in _test_eintr.py.
diff --git a/Lib/test/_test_eintr.py b/Lib/test/_test_eintr.py
@@ -163,7 +163,6 @@ def test_readinto(self):
             self.assertEqual(os.readinto(fd, buffer), len(expected))
             self.assertEqual(buffer, expected)
 
-    @unittest.expectedFailure  # TODO: RUSTPYTHON; InterruptedError: [Errno 4] Interrupted system call
     def test_write(self):
         rd, wr = os.pipe()
         self.addCleanup(os.close, wr)
diff --git a/crates/vm/src/stdlib/os.rs b/crates/vm/src/stdlib/os.rs
@@ -325,8 +325,17 @@ pub(super) mod _os {
         fd: crt_fd::Borrowed<'_>,
         data: ArgBytesLike,
         vm: &VirtualMachine,
-    ) -> io::Result<usize> {
-        data.with_ref(|b| vm.allow_threads(|| crt_fd::write(fd, b)))
+    ) -> PyResult<usize> {
+        data.with_ref(|b| loop {
+            match vm.allow_threads(|| crt_fd::write(fd, b)) {
+                Ok(n) => return Ok(n),
+                Err(e) if e.raw_os_error() == Some(libc::EINTR) => {
+                    vm.check_signals()?;
+                    continue;
+                }
+                Err(e) => return Err(e.into_pyexception(vm)),
+            }
+        })
     }
 
     #[cfg(not(windows))]
