Alex Bennée <[email protected]> writes:
> [email protected] writes:
>
>> From: Marc-André Lureau <[email protected]>
>>
>> As per comment, presumably to avoid syscall in critical section.
>>
>> Fixes: 0210c3b39bef08 ("monitor: Use LOCK_GUARD macros")
>> Signed-off-by: Marc-André Lureau <[email protected]>
>
> I know this is already merged but as an academic exercise we could have
> kept the lock guard with a little restructuring like this:
>
> void qmp_closefd(const char *fdname, Error **errp)
Marc-André is patching qmp_getfd(), not qmp_closefd().
> {
> Monitor *cur_mon = monitor_cur();
> mon_fd_t *monfd;
> int tmp_fd = -1;
>
> WITH_QEMU_LOCK_GUARD(&cur_mon->mon_lock) {
> QLIST_FOREACH(monfd, &cur_mon->fds, next) {
> if (strcmp(monfd->name, fdname) != 0) {
> continue;
> }
>
> QLIST_REMOVE(monfd, next);
> tmp_fd = monfd->fd;
> g_free(monfd->name);
> g_free(monfd);
> break;
> }
> }
>
> if (tmp_fd > 0) {
> /* close() must be outside critical section */
> close(tmp_fd);
> } else {
> error_setg(errp, "File descriptor named '%s' not found", fdname);
> }
> }
>
> To my mind it makes it easier to reason about locking but I probably
> have an irrational aversion to multiple exit paths for locks.
