node exits with error: getWindowSize EINTR

[jkryl]

• Version: v4.3.0
• Platform: SunOS with 32bit userland

Occasionally (happens once a month or so) the node process exits with following message on screen:

Error: getWindowSize EINTR
    at exports._errnoException (util.js:870:11)
    at WriteStream._refreshSize (tty.js:82:24)
    at process.<anonymous> (node.js:638:18)
    at emitNone (events.js:72:20)
    at process.emit (events.js:166:7)
    at Signal.wrap.onsignal (node.js:802:46)

What I think that happens is that the node is trying to get new size of screen after receiving SIGWINCH signal and the call to getWindowSize is interrupted by another signal and because SA_RESTART flag for sigaction() is not set by default on solaris unlike on other platforms, the interrupted syscall is not repeated and EINTR error is emitted on stream (

node/lib/tty.js

Line 71 in fdeb862

this.emit('error', errnoException(err, 'getWindowSize'));

) and makes the program to exit. I have no reproducible test case or proof that my assumptions are correct. Also I have seen a couple of places in nodejs code where EINTR is explicitly checked and function call repeated if that's the case. Perhaps something similar could be done for this piece of code as well.

[bnoordhuis]

That sounds plausible. It's probably Solaris-specific because I don't think the other Unixes return EINTR from ioctl(TIOCGWINSZ).

This patch should help. I'll get it upstreamed in libuv:

diff --git a/deps/uv/src/unix/tty.c b/deps/uv/src/unix/tty.c
index 7cc5b71..f62b59f 100644
--- a/deps/uv/src/unix/tty.c
+++ b/deps/uv/src/unix/tty.c
@@ -185,8 +185,13 @@ int uv_tty_set_mode(uv_tty_t* tty, uv_tty_mode_t mode) {

 int uv_tty_get_winsize(uv_tty_t* tty, int* width, int* height) {
   struct winsize ws;
+  int err;
+
+  do
+    err = ioctl(uv__stream_fd(tty), TIOCGWINSZ, &ws);
+  while (err == -1 && errno == EINTR);

-  if (ioctl(uv__stream_fd(tty), TIOCGWINSZ, &ws))
+  if (err)
     return -errno;

   *width = ws.ws_col;

[jkryl]

Thanks for quick response and the patch!