On Thu, Dec 03, 2020 at 01:57:21PM +0000, Stefan Hajnoczi wrote:
On Tue, Nov 24, 2020 at 08:08:26PM +0800, Coiby Xu wrote:
Hi Stefan,
On Wed, Nov 11, 2020 at 12:43:26PM +0000, Stefan Hajnoczi wrote:
> Do not leave stdin and stdout open after fork. stdout is the
> tap-driver.pl pipe. If we keep the pipe open then tap-driver.pl will not
> detect that qos-test has terminated and it will hang.
I wonder under which situation this would happen. I couldn't re-produce
this issue locally.
Try adding g_assert_not_reached() to one of the tests so the qos-test
process aborts. Then tap-driver.pl will hang because the pipe hasn't
been closed and "make check" never completes.
Thank you for the explanation! I thought closing fork child file is
for dealing with a subtle race condition. So it's actually for dealing
with the situation when g_assert_* fails.
Do you think g_spawn_async_with_pipes is a better way than fork/exec
since g_spawn_* could help us take care of closing standard file
descriptors?
g_test_message("starting vhost-user backend: %s",
storage_daemon_command->str);
GPid child_pid;
g_autoptr(GError) error = NULL;
const gchar * const argv[] = { "/bin/sh", "-c",
storage_daemon_command->str, NULL };
g_spawn_async_with_pipes (NULL, argv, NULL, G_SPAWN_STDOUT_TO_DEV_NULL,
NULL,
NULL, &child_pid, NULL, NULL,
NULL, &error);
if (error != NULL)
{
g_error ("Starting qemu-storage-daemon failed: %s", error->message);
abort();
}
g_string_free(storage_daemon_command, true);
--
Best regards,
Coiby
