From: Jaroslav Kysela <perex@perex.cz>
Date: Tue, 13 Feb 2001 12:53:19 +0000 (+0000)
Subject: Added the safe version of the list_for_each function.
X-Git-Tag: v1.0.3~963
X-Git-Url: https://git.alsa-project.org/?a=commitdiff_plain;h=6ea4260c1c2100ced5ad69d34330a331bd53b887;p=alsa-lib.git

Added the safe version of the list_for_each function.
---

diff --git a/aserver/aserver.c b/aserver/aserver.c
index e15221a2..dcf8d0a9 100644
--- a/aserver/aserver.c
+++ b/aserver/aserver.c
@@ -753,7 +753,7 @@ int inet_pending_handler(waiter_t *waiter, unsigned short events)
 	inet_pending_t *pdata;
 	client_t *client;
 	uint32_t cookie;
-	struct list_head *item, *next;
+	struct list_head *item;
 	int remove = 0;
 	if (events & POLLHUP)
 		remove = 1;
@@ -775,7 +775,7 @@ int inet_pending_handler(waiter_t *waiter, unsigned short events)
 		return 0;
 	}
 
-	list_for_each(item, next, &inet_pendings) {
+	list_for_each(item, &inet_pendings) {
 		pdata = list_entry(item, inet_pending_t, list);
 		if (pdata->cookie == cookie)
 			goto found;
diff --git a/include/list.h b/include/list.h
index 90f54951..65c81422 100644
--- a/include/list.h
+++ b/include/list.h
@@ -139,10 +139,18 @@ static __inline__ void list_splice(struct list_head *list, struct list_head *hea
 /**
  * list_for_each	-	iterate over a list
  * @pos:	the &struct list_head to use as a loop counter.
+ * @head:	the head for your list.
+ */
+#define list_for_each(pos, head) \
+	for (pos = (head)->next ; pos != (head); pos = pos->next)
+
+/**
+ * list_for_each_safe	-	iterate over a list safely (actual pointer can be invalidated)
+ * @pos:	the &struct list_head to use as a loop counter.
  * @next:	the &struct list_head to use to save next.
  * @head:	the head for your list.
  */
-#define list_for_each(pos, npos, head) \
+#define list_for_each_safe(pos, npos, head) \
 	for (pos = (head)->next, npos = pos->next ; pos != (head); pos = npos, npos = pos->next)
 
 /**
diff --git a/src/mixer/bag.c b/src/mixer/bag.c
index d1c5c544..69444e05 100644
--- a/src/mixer/bag.c
+++ b/src/mixer/bag.c
@@ -54,8 +54,8 @@ int bag_add(bag_t *bag, void *ptr)
 
 int bag_del(bag_t *bag, void *ptr)
 {
-	struct list_head *pos, *next;
-	list_for_each(pos, next, bag) {
+	struct list_head *pos;
+	list_for_each(pos, bag) {
 		bag1_t *b = list_entry(pos, bag1_t, list);
 		if (b->ptr == ptr) {
 			list_del(&b->list);
diff --git a/src/mixer/mixer.c b/src/mixer/mixer.c
index efce4307..ea58ab3c 100644
--- a/src/mixer/mixer.c
+++ b/src/mixer/mixer.c
@@ -96,8 +96,8 @@ static int hctl_elem_event_handler(snd_hctl_elem_t *helem,
 	case SND_CTL_EVENT_INFO:
 	{
 		int err = 0;
-		bag_iterator_t i, n;
-		bag_for_each(i, n, bag) {
+		bag_iterator_t i;
+		bag_for_each(i, bag) {
 			snd_mixer_elem_t *melem = bag_iterator_entry(i);
 			snd_mixer_class_t *class = melem->class;
 			err = class->event(class, event, helem, melem);
@@ -110,7 +110,7 @@ static int hctl_elem_event_handler(snd_hctl_elem_t *helem,
 	{
 		int err;
 		bag_iterator_t i, n;
-		bag_for_each(i, n, bag) {
+		bag_for_each_safe(i, n, bag) {
 			snd_mixer_elem_t *melem = bag_iterator_entry(i);
 			snd_mixer_class_t *class = melem->class;
 			err = class->event(class, event, helem, melem);
@@ -137,14 +137,14 @@ static int hctl_event_handler(snd_hctl_t *hctl, snd_ctl_event_type_t event,
 	switch (event) {
 	case SND_CTL_EVENT_ADD:
 	{
-		struct list_head *pos, *next;
+		struct list_head *pos;
 		bag_t *bag;
 		int err = bag_new(&bag);
 		if (err < 0)
 			return err;
 		snd_hctl_elem_set_callback(elem, hctl_elem_event_handler);
 		snd_hctl_elem_set_callback_private(elem, bag);
-		list_for_each(pos, next, &mixer->classes) {
+		list_for_each(pos, &mixer->classes) {
 			snd_mixer_class_t *c;
 			c = list_entry(pos, snd_mixer_class_t, list);
 			err = c->event(c, event, elem, NULL);
@@ -189,8 +189,8 @@ int snd_mixer_attach(snd_mixer_t *mixer, const char *name)
 
 int snd_mixer_detach(snd_mixer_t *mixer, const char *name)
 {
-	struct list_head *pos, *next;
-	list_for_each(pos, next, &mixer->slaves) {
+	struct list_head *pos;
+	list_for_each(pos, &mixer->slaves) {
 		snd_mixer_slave_t *s;
 		s = list_entry(pos, snd_mixer_slave_t, list);
 		if (strcmp(name, snd_hctl_name(s->hctl)) == 0) {
@@ -292,11 +292,9 @@ int snd_mixer_elem_remove(snd_mixer_elem_t *elem)
 	idx = _snd_mixer_find_elem(mixer, elem, &dir);
 	if (dir != 0)
 		return -EINVAL;
-      __again:
-	bag_for_each(i, n, &elem->helems) {
+	bag_for_each_safe(i, n, &elem->helems) {
 		snd_hctl_elem_t *helem = bag_iterator_entry(i);
 		snd_mixer_elem_detach(elem, helem);
-		goto __again;		/* FIXME: optimize */
 	}
 	err = snd_mixer_elem_throw_event(elem, SND_CTL_EVENT_REMOVE);
 	list_del(&elem->list);
@@ -320,12 +318,12 @@ int snd_mixer_elem_change(snd_mixer_elem_t *elem)
 
 int snd_mixer_class_register(snd_mixer_class_t *class, snd_mixer_t *mixer)
 {
-	struct list_head *pos, *next;
+	struct list_head *pos;
 	class->mixer = mixer;
 	list_add_tail(&class->list, &mixer->classes);
 	if (!class->event)
 		return 0;
-	list_for_each(pos, next, &mixer->slaves) {
+	list_for_each(pos, &mixer->slaves) {
 		int err;
 		snd_mixer_slave_t *slave;
 		snd_hctl_elem_t *elem;
@@ -360,8 +358,8 @@ int snd_mixer_class_unregister(snd_mixer_class_t *class)
 
 int snd_mixer_load(snd_mixer_t *mixer)
 {
-	struct list_head *pos, *next;
-	list_for_each(pos, next, &mixer->slaves) {
+	struct list_head *pos;
+	list_for_each(pos, &mixer->slaves) {
 		int err;
 		snd_mixer_slave_t *s;
 		s = list_entry(pos, snd_mixer_slave_t, list);
@@ -374,8 +372,8 @@ int snd_mixer_load(snd_mixer_t *mixer)
 
 void snd_mixer_free(snd_mixer_t *mixer)
 {
-	struct list_head *pos, *next;
-	list_for_each(pos, next, &mixer->slaves) {
+	struct list_head *pos;
+	list_for_each(pos, &mixer->slaves) {
 		snd_mixer_slave_t *s;
 		s = list_entry(pos, snd_mixer_slave_t, list);
 		snd_hctl_free(s->hctl);
@@ -456,10 +454,10 @@ int snd_mixer_set_compare(snd_mixer_t *mixer, snd_mixer_compare_t msort)
 
 int snd_mixer_poll_descriptors(snd_mixer_t *mixer, struct pollfd *pfds, unsigned int space)
 {
-	struct list_head *pos, *next;
+	struct list_head *pos;
 	unsigned int count = 0;
 	assert(mixer);
-	list_for_each(pos, next, &mixer->slaves) {
+	list_for_each(pos, &mixer->slaves) {
 		snd_mixer_slave_t *s;
 		int n;
 		s = list_entry(pos, snd_mixer_slave_t, list);
@@ -532,10 +530,10 @@ snd_mixer_elem_t *snd_mixer_elem_prev(snd_mixer_elem_t *elem)
 
 int snd_mixer_handle_events(snd_mixer_t *mixer)
 {
-	struct list_head *pos, *next;
+	struct list_head *pos;
 	assert(mixer);
 	mixer->events = 0;
-	list_for_each(pos, next, &mixer->slaves) {
+	list_for_each(pos, &mixer->slaves) {
 		int err;
 		snd_mixer_slave_t *s;
 		s = list_entry(pos, snd_mixer_slave_t, list);
diff --git a/src/mixer/mixer_local.h b/src/mixer/mixer_local.h
index 0e8dd9fe..5910d0fa 100644
--- a/src/mixer/mixer_local.h
+++ b/src/mixer/mixer_local.h
@@ -39,7 +39,8 @@ int bag_empty(bag_t *bag);
 typedef struct list_head *bag_iterator_t;
 
 #define bag_iterator_entry(i) (list_entry((i), bag1_t, list)->ptr)
-#define bag_for_each(pos, next, bag) list_for_each(pos, next, bag)
+#define bag_for_each(pos, bag) list_for_each(pos, bag)
+#define bag_for_each_safe(pos, next, bag) list_for_each_safe(pos, next, bag)
 
 #define MIXER_COMPARE_WEIGHT_SIMPLE_BASE	0
 #define MIXER_COMPARE_WEIGHT_NEXT_BASE		10000000
diff --git a/src/mixer/simple.c b/src/mixer/simple.c
index 1eeb6546..889cad04 100644
--- a/src/mixer/simple.c
+++ b/src/mixer/simple.c
@@ -836,8 +836,8 @@ int snd_mixer_selem_register(snd_mixer_t *mixer, snd_mixer_class_t **classp)
 snd_mixer_elem_t *snd_mixer_find_selem(snd_mixer_t *mixer,
 				       const snd_mixer_selem_id_t *id)
 {
-	struct list_head *list, *next;
-	list_for_each(list, next, &mixer->elems) {
+	struct list_head *list;
+	list_for_each(list, &mixer->elems) {
 		snd_mixer_elem_t *e;
 		selem_t *s;
 		e = list_entry(list, snd_mixer_elem_t, list);