wayland: roundtrip: log error and abort when wl_display_roundtrip() fails

ayl_roundtrip() has the following code:

    wl_display_roundtrip(wayl->display);

    while (wl_display_prepare_read(wayl->display) != 0)
        wl_display_dispatch_pending(wayl->display);
    wayl_flush(wayl);

If the first wl_display_roundtrip() fails, for example because the
Wayland socket has been closed, we may get stuck in the while-loop.

This happens if the read queue isn’t empty, in which case
wl_display_prepare_read() will return -1 and we’ll continue trying to
dispatch the pending events forever, never succeeding since the socket
is gone.

Closes #542
This commit is contained in:
Daniel Eklöf 2021-05-24 20:42:55 +02:00
parent 361fb74a8f
commit 7bdecaae3b
No known key found for this signature in database
GPG key ID: 5BBD4992C116573F
2 changed files with 13 additions and 3 deletions

View file

@ -126,6 +126,9 @@
* Rare occurrences where the window did not close when the shell
exited. Only seen on FreeBSD
(https://codeberg.org/dnkl/foot/issues/534)
* Foot process(es) sometimes remaining, using 100% CPU, when closing
multiple foot windows at the same time
(https://codeberg.org/dnkl/foot/issues/542).
### Security

View file

@ -1589,14 +1589,21 @@ void
wayl_roundtrip(struct wayland *wayl)
{
wl_display_cancel_read(wayl->display);
wl_display_roundtrip(wayl->display);
if (wl_display_roundtrip(wayl->display) < 0) {
LOG_ERRNO("failed to roundtrip Wayland display");
return;
}
/* I suspect the roundtrip above clears the pending queue, and
* that prepare_read() will always succeed in the first call. But,
* better safe than sorry... */
while (wl_display_prepare_read(wayl->display) != 0)
wl_display_dispatch_pending(wayl->display);
while (wl_display_prepare_read(wayl->display) != 0) {
if (wl_display_dispatch_pending(wayl->display) < 0) {
LOG_ERRNO("failed to dispatch pending Wayland events");
return;
}
}
wayl_flush(wayl);
}