On FreeBSD polling a master pty while the other end is not connected
with G_IO_OUT only results in an endless wait. This is different from
the Linux behaviour, that returns immediately. In order to demonstrate
this, I have the following example code:
http://xenbits.xen.org/people/royger/test_poll.c
When executed on Linux:
$ ./test_poll
In callback
On FreeBSD instead, the callback never gets called:
$ ./test_poll
So, in order to workaround this, poll the source with G_IO_HUP (which
makes the code behave the same way on both Linux and FreeBSD).
Signed-off-by: Roger Pau Monné <roger....@citrix.com>
Cc: Peter Crosthwaite <peter.crosthwa...@xilinx.com>
Cc: Michael Tokarev <m...@tls.msk.ru>
Cc: "Andreas Färber" <afaer...@suse.de>
Cc: Paolo Bonzini <pbonz...@redhat.com>
Cc: xen-de...@lists.xenproject.org
---
Changes since v1:
- Fix other users of qemu_chr_fe_add_watch to use G_IO_HUP.
---
hw/char/serial.c | 2 +-
hw/char/virtio-console.c | 3 ++-
hw/usb/redirect.c | 2 +-
monitor.c | 2 +-
4 files changed, 5 insertions(+), 4 deletions(-)
diff --git a/hw/char/serial.c b/hw/char/serial.c
index f4d167f..2a2c9e5 100644
--- a/hw/char/serial.c
+++ b/hw/char/serial.c
@@ -246,7 +246,7 @@ static gboolean serial_xmit(GIOChannel *chan, GIOCondition
cond, void *opaque)
serial_receive1(s, &s->tsr, 1);
} else if (qemu_chr_fe_write(s->chr, &s->tsr, 1) != 1) {
if (s->tsr_retry >= 0 && s->tsr_retry < MAX_XMIT_RETRY &&
- qemu_chr_fe_add_watch(s->chr, G_IO_OUT, serial_xmit, s) > 0) {
+ qemu_chr_fe_add_watch(s->chr, G_IO_OUT|G_IO_HUP, serial_xmit, s) >
0) {
s->tsr_retry++;
return FALSE;
}
diff --git a/hw/char/virtio-console.c b/hw/char/virtio-console.c
index 6c8be0f..38e290a 100644
--- a/hw/char/virtio-console.c
+++ b/hw/char/virtio-console.c
@@ -69,7 +69,8 @@ static ssize_t flush_buf(VirtIOSerialPort *port,
if (!k->is_console) {
virtio_serial_throttle_port(port, true);
if (!vcon->watch) {
- vcon->watch = qemu_chr_fe_add_watch(vcon->chr, G_IO_OUT,
+ vcon->watch = qemu_chr_fe_add_watch(vcon->chr,
+ G_IO_OUT|G_IO_HUP,
chr_write_unblocked, vcon);
}
}
diff --git a/hw/usb/redirect.c b/hw/usb/redirect.c
index 287a505..06e757d 100644
--- a/hw/usb/redirect.c
+++ b/hw/usb/redirect.c
@@ -284,7 +284,7 @@ static int usbredir_write(void *priv, uint8_t *data, int
count)
r = qemu_chr_fe_write(dev->cs, data, count);
if (r < count) {
if (!dev->watch) {
- dev->watch = qemu_chr_fe_add_watch(dev->cs, G_IO_OUT,
+ dev->watch = qemu_chr_fe_add_watch(dev->cs, G_IO_OUT|G_IO_HUP,
usbredir_write_unblocked, dev);
}
if (r < 0) {
diff --git a/monitor.c b/monitor.c
index 593679a..ae1c539 100644
--- a/monitor.c
+++ b/monitor.c
@@ -304,7 +304,7 @@ void monitor_flush(Monitor *mon)
mon->outbuf = tmp;
}
if (mon->watch == 0) {
- mon->watch = qemu_chr_fe_add_watch(mon->chr, G_IO_OUT,
+ mon->watch = qemu_chr_fe_add_watch(mon->chr, G_IO_OUT|G_IO_HUP,
monitor_unblocked, mon);
}
}
