On Tue, Dec 13, 2016 at 02:19:47PM +0100, Jan Wickbom wrote:
> +
> + poll(pfdset->rwfds, numfds, 1000 /* millisecs */);
> +
> + for (i = 0; i < numfds; ) {
> pthread_mutex_lock(&pfdset->fd_mutex);
> +
> pfdentry = &pfdset->fd[i];
> fd = pfdentry->fd;
> + pfd = &pfdset->rwfds[i];
> +
> + if (fd < 0) {
> + /* Removed during poll */
> + /* shrink first, last migth be deleted*/
> +
> + fdset_shrink(pfdset);
> + fdset_move_last(pfdset, i);
> + fdset_shrink(pfdset);
> +
> + pthread_mutex_unlock(&pfdset->fd_mutex);
This patch looks better, but as said, I will not do shrink in the
event processing loop: I would simply set a flag, something like
"need_shrink" here, and do the shrink outside this for loop.
> + if (remove1 || remove2) {
> + pthread_mutex_lock(&pfdset->fd_mutex);
> +
> + /* shrink first, last migth be deleted*/
> + fdset_shrink(pfdset);
> + fdset_move_last(pfdset, i);
> + fdset_shrink(pfdset);
> +
> + pthread_mutex_unlock(&pfdset->fd_mutex);
> +
> + continue;
Same here: just sets a flag.
> + }
> +
> + i++;
> }
> +
> + /* fdset_del do not shrink, pack eventual remainings of array */
> + pthread_mutex_lock(&pfdset->fd_mutex);
> +
> + fdset_shrink(pfdset);
> +
> + for ( ; i < pfdset->num; i++) {
> + pfdentry = &pfdset->fd[i];
> +
> + if (pfdentry->fd < 0) {
> + fdset_move_last(pfdset, i);
> + fdset_shrink(pfdset);
> + }
> + }
And yes, do the shrink here (when the shrink flag is set). But I would
simply call fdset_shrink() here (without the for loop), and let the
fdset_shrink() to handle the details: it could either be a swap with
last __valid__ entry, or simply a memmov.
That said, if you prefer to choose fdset_move_last(), fine, invoke it
inside fdset_shrink() then. Let fdset_shrink be able to remove an fd
in the middle.
> +
> + pthread_mutex_unlock(&pfdset->fd_mutex);
> }
> }
> diff --git a/lib/librte_vhost/fd_man.h b/lib/librte_vhost/fd_man.h
> index bd66ed1..03e7881 100644
> --- a/lib/librte_vhost/fd_man.h
> +++ b/lib/librte_vhost/fd_man.h
> @@ -35,6 +35,7 @@
> #define _FD_MAN_H_
> #include <stdint.h>
> #include <pthread.h>
> +#include <poll.h>
>
> #define MAX_FDS 1024
>
> @@ -49,9 +50,10 @@ struct fdentry {
> };
>
> struct fdset {
> + struct pollfd rwfds[MAX_FDS];
> struct fdentry fd[MAX_FDS];
> pthread_mutex_t fd_mutex;
> - int num; /* current fd number of this fdset */
> + int num; /* highest index occupied in fd array + 1 */
I don't see the comment change makes it more readable.
--yliu
