On 2011-02-18 14:17, Tristan Gingold wrote:
> Fix compilation failure on Darwin.
>
> Signed-off-by: Tristan Gingold <ging...@adacore.com>
> ---
> compatfd.c | 36 ++++++++++++++++++------------------
> 1 files changed, 18 insertions(+), 18 deletions(-)
>
> diff --git a/compatfd.c b/compatfd.c
> index a7cebc4..bd377c4 100644
> --- a/compatfd.c
> +++ b/compatfd.c
> @@ -26,45 +26,45 @@ struct sigfd_compat_info
> static void *sigwait_compat(void *opaque)
> {
> struct sigfd_compat_info *info = opaque;
> - int err;
> sigset_t all;
>
> sigfillset(&all);
> sigprocmask(SIG_BLOCK, &all, NULL);
>
> - do {
> - siginfo_t siginfo;
> + while (1) {
> + int sig;
> + int err;
>
> - err = sigwaitinfo(&info->mask, &siginfo);
> - if (err == -1 && errno == EINTR) {
> - err = 0;
> - continue;
> - }
> -
> - if (err > 0) {
> - char buffer[128];
> + err = sigwait(&info->mask, &sig);
> + if (err != 0) {
> + if (errno == EINTR) {
> + continue;
> + } else {
> + return NULL;
> + }
> + } else {
> + struct qemu_signalfd_siginfo buffer;
> size_t offset = 0;
>
> - memcpy(buffer, &err, sizeof(err));
> + memset(&buffer, 0, sizeof(buffer));
> + buffer.ssi_signo = sig;
> +
> while (offset < sizeof(buffer)) {
> ssize_t len;
>
> - len = write(info->fd, buffer + offset,
> + len = write(info->fd, (char *)&buffer + offset,
> sizeof(buffer) - offset);
> if (len == -1 && errno == EINTR)
> continue;
>
> if (len <= 0) {
> - err = -1;
> - break;
> + return NULL;
This and the above handling of sigwait return codes changes the error
handling strategy. So far we silently skipped errors, now we silently
terminate the compatfd thread. I think none of both approaches is good.
Failing sigwait is likely a reason to bail out, but loudly, writing some
error message to the console and triggering a shutdown of qemu.
An overflow of the compatfd pipe to the main thread may be due to some
very unfortunate overload scenario. Not sure if that qualifies for a
thread termination (definitely not for a silent one).
Error handling should probably be adjusted independently of this darwin
build fix.
Jan
--
Siemens AG, Corporate Technology, CT T DE IT 1
Corporate Competence Center Embedded Linux
