Dne 5.10.2018 v 16:47 Takashi Sakamoto napsal(a):
> At present, handlers for control nodes are maintained by one-dimensional
> array. This is not necessarily useful to maintain handlers with
> associated information.
>
> This commit adds link-list for the maintenance.
Thanks for the improved code.
Please, use macros in list.h to manage linked list which are inherited
from the kernel here.
Jaroslav
>
> Signed-off-by: Takashi Sakamoto <o-takashi@xxxxxxxxxxxxx>
> ---
> alsactl/monitor.c | 84 +++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 84 insertions(+)
>
> diff --git a/alsactl/monitor.c b/alsactl/monitor.c
> index cf5c50a..8b16307 100644
> --- a/alsactl/monitor.c
> +++ b/alsactl/monitor.c
> @@ -29,6 +29,16 @@
> static int signal_type;
> static bool interrupted;
>
> +struct src_entry {
> + snd_ctl_t *handle;
> + char *name;
> + unsigned int pfd_count;
> + struct {
> + struct src_entry *prev;
> + struct src_entry *next;
> + } list;
> +};
> +
> #define MAX_CARDS 256
>
> struct snd_card_iterator {
> @@ -59,6 +69,72 @@ static const char *snd_card_iterator_next(struct snd_card_iterator *iter)
> return (const char *)iter->name;
> }
>
> +static inline void remove_source_entry(struct src_entry *src)
> +{
> + struct src_entry *prev = src->list.prev;
> + struct src_entry *next = src->list.next;
> +
> + if (prev)
> + prev->list.next = src->list.next;
> + if (next)
> + next->list.prev = src->list.prev;
> + free(src->name);
> + free(src);
> +}
> +
> +static void clear_source_list(struct src_entry **srcs)
> +{
> + while (*srcs) {
> + struct src_entry *src = *srcs;
> + *srcs = src->list.next;
> +
> + remove_source_entry(src);
> + }
> +}
> +
> +static int insert_source_entry(struct src_entry **head, snd_ctl_t *handle,
> + const char *name)
> +{
> + struct src_entry *src;
> + int count;
> + int err;
> +
> + src = calloc(1, sizeof(*src));
> + if (!src)
> + return -ENOMEM;
> + src->handle = handle;
> +
> + src->name = strdup(name);
> + if (!src->name) {
> + err = -ENOMEM;
> + goto error;
> + }
> +
> + count = snd_ctl_poll_descriptors_count(handle);
> + if (count < 0) {
> + err = count;
> + goto error;
> + }
> + if (count == 0) {
> + err = -ENXIO;
> + goto error;
> + }
> + src->pfd_count = count;
> +
> + if (*head) {
> + src->list.next = (*head)->list.next;
> + src->list.prev = *head;
> + (*head)->list.next = src;
> + } else {
> + *head = src;
> + }
> +
> + return 0;
> +error:
> + free(src);
> + return err;
> +}
> +
> static int open_ctl(const char *name, snd_ctl_t **ctlp)
> {
> snd_ctl_t *ctl;
> @@ -259,6 +335,7 @@ static int prepare_signal_handler(void)
>
> int monitor(const char *name)
> {
> + struct src_entry *srcs = NULL;
> snd_ctl_t *ctls[MAX_CARDS] = {0};
> int ncards = 0;
> int show_cards;
> @@ -281,6 +358,9 @@ int monitor(const char *name)
> snd_card_iterator_init(&iter);
> while ((cardname = snd_card_iterator_next(&iter))) {
> err = open_ctl(cardname, &ctls[ncards]);
> + if (err < 0)
> + goto error;
> + err = insert_source_entry(&srcs, ctls[ncards], cardname);
> if (err < 0)
> goto error;
> ++ncards;
> @@ -288,6 +368,9 @@ int monitor(const char *name)
> show_cards = 1;
> } else {
> err = open_ctl(name, &ctls[0]);
> + if (err < 0)
> + goto error;
> + err = insert_source_entry(&srcs, ctls[ncards], name);
> if (err < 0)
> goto error;
> ncards++;
> @@ -300,6 +383,7 @@ int monitor(const char *name)
> clear_dispatcher(epfd, ctls, ncards);
>
> error:
> + clear_source_list(&srcs);
> for (i = 0; i < ncards; i++) {
> if (ctls[i])
> snd_ctl_close(ctls[i]);
>
--
Jaroslav Kysela <perex@xxxxxxxx>
Linux Sound Maintainer; ALSA Project; Red Hat, Inc.
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