linkedlist helpers

diff --git a/lib/libwebsockets.h b/lib/libwebsockets.h
index 3358910..2e79395 100644 (file)
--- a/lib/libwebsockets.h
+++ b/lib/libwebsockets.h
@@ -4197,6 +4197,74 @@ lws_interface_to_sa(int ipv6, const char *ifname, struct sockaddr_in *addr,
 ///@{
 
 /**
+ * lws_start_foreach_ll(): linkedlist iterator helper start
+ *
+ * \param type: type of iteration, eg, struct xyz *
+ * \param it: iterator var name to create
+ * \param start: start of list
+ *
+ * This helper creates an iterator and starts a while (it) {
+ * loop.  The iterator runs through the linked list starting at start and
+ * ends when it gets a NULL.
+ * The while loop should be terminated using lws_start_foreach_ll().
+ */
+#define lws_start_foreach_ll(type, it, start)\
+{ \
+       type it = start; \
+       while (it) {
+
+/**
+ * lws_end_foreach_ll(): linkedlist iterator helper end
+ *
+ * \param it: same iterator var name given when starting
+ * \param nxt: member name in the iterator pointing to next list element
+ *
+ * This helper is the partner for lws_start_foreach_ll() that ends the
+ * while loop.
+ */
+
+#define lws_end_foreach_ll(it, nxt) \
+               it = it->nxt; \
+       } \
+}
+
+/**
+ * lws_start_foreach_llp(): linkedlist pointer iterator helper start
+ *
+ * \param type: type of iteration, eg, struct xyz **
+ * \param it: iterator var name to create
+ * \param start: start of list
+ *
+ * This helper creates an iterator and starts a while (it) {
+ * loop.  The iterator runs through the linked list starting at the
+ * address of start and ends when it gets a NULL.
+ * The while loop should be terminated using lws_start_foreach_llp().
+ *
+ * This helper variant iterates using a pointer to the previous linked-list
+ * element.  That allows you to easily delete list members by rewriting the
+ * previous pointer to the element's next pointer.
+ */
+#define lws_start_foreach_llp(type, it, start)\
+{ \
+       type it = &(start); \
+       while (*(it)) {
+
+/**
+ * lws_end_foreach_llp(): linkedlist pointer iterator helper end
+ *
+ * \param it: same iterator var name given when starting
+ * \param nxt: member name in the iterator pointing to next list element
+ *
+ * This helper is the partner for lws_start_foreach_llp() that ends the
+ * while loop.
+ */
+
+#define lws_end_foreach_llp(it, nxt) \
+               it = &(*(it))->nxt; \
+       } \
+}
+
+/**
  * lws_snprintf(): snprintf that truncates the returned length too
  *
  * \param str: destination buffer

diff --git a/plugins/protocol_lws_mirror.c b/plugins/protocol_lws_mirror.c
index 33af7ce..afac1b6 100644 (file)
--- a/plugins/protocol_lws_mirror.c
+++ b/plugins/protocol_lws_mirror.c
@@ -68,13 +68,12 @@ callback_lws_mirror(struct lws *wsi, enum lws_callback_reasons reason,
                    void *user, void *in, size_t len)
 {
        struct per_session_data__lws_mirror *pss =
-                       (struct per_session_data__lws_mirror *)user, **ppss,
-                       *pss1;
+                       (struct per_session_data__lws_mirror *)user;
        struct per_vhost_data__lws_mirror *v =
                        (struct per_vhost_data__lws_mirror *)
                        lws_protocol_vh_priv_get(lws_get_vhost(wsi),
                                        lws_get_protocol(wsi));
-       struct lws_mirror_instance *mi, **pmi;
+       struct lws_mirror_instance *mi = NULL;
        char name[30];
        int n, m, count_mi = 0;
 
@@ -95,17 +94,16 @@ callback_lws_mirror(struct lws *wsi, enum lws_callback_reasons reason,
 
                /* is there already a mirror instance of this name? */
 
-               mi = v->mi_list;
-               while (mi) {
-                       if (!strcmp(name, mi->name)) {
-                               lwsl_notice("Joining existing mi %p '%s'\n",
-                                               mi, name);
-                               /* yes... we will join it */
-                               break;
-                       }
+               lws_start_foreach_ll(struct lws_mirror_instance *,
+                                    mi1, v->mi_list) {
                        count_mi++;
-                       mi = mi->next;
-               }
+                       if (strcmp(name, mi1->name))
+                               continue;
+                       /* yes... we will join it */
+                       lwsl_notice("Joining existing mi %p '%s'\n", mi1, name);
+                       mi = mi1;
+                       break;
+               } lws_end_foreach_ll(mi1, next);
 
                if (!mi) {
 
@@ -123,7 +121,6 @@ callback_lws_mirror(struct lws *wsi, enum lws_callback_reasons reason,
                        strcpy(mi->name, name);
                        mi->ringbuffer_head = 0;
 
-
                        lwsl_notice("Created new mi %p '%s'\n", mi, name);
                }
 
@@ -147,42 +144,40 @@ callback_lws_mirror(struct lws *wsi, enum lws_callback_reasons reason,
                mi = pss->mi;
                if (!mi)
                        break;
-               ppss = &mi->same_mi_pss_list;
 
-               while (*ppss) {
+               lws_start_foreach_llp(struct per_session_data__lws_mirror **,
+                       ppss, mi->same_mi_pss_list) {
                        if (*ppss == pss) {
+
                                *ppss = pss->same_mi_pss_list;
                                break;
                        }
+               } lws_end_foreach_llp(ppss, same_mi_pss_list);
 
-                       ppss = &(*ppss)->same_mi_pss_list;
-               }
+               pss->mi = NULL;
 
-               if (!mi->same_mi_pss_list) {
+               if (mi->same_mi_pss_list)
+                       break;
 
-                       /* last pss unbound from mi... delete mi */
+               /* last pss unbound from mi... delete mi */
 
-                       pmi = &v->mi_list;
-                       while (*pmi) {
-                               if (*pmi == mi) {
-                                       *pmi = (*pmi)->next;
+               lws_start_foreach_llp(struct lws_mirror_instance **,
+                               pmi, v->mi_list) {
+                       if (*pmi != mi)
+                               continue;
 
-                                       if (!pss->mi)
-                                               break;
-                                       lwsl_info("%s: mirror protocol cleaning up %p\n", __func__, v);
-                                       for (n = 0; n < ARRAY_SIZE(pss->mi->ringbuffer); n++)
-                                               if (pss->mi->ringbuffer[n].payload) {
-                                                       free(pss->mi->ringbuffer[n].payload);
-                                                       pss->mi->ringbuffer[n].payload = NULL;
-                                               }
+                       *pmi = (*pmi)->next;
 
-                                       free(mi);
-                                       break;
+                       lwsl_info("%s: mirror cleaniup %p\n", __func__, v);
+                       for (n = 0; n < ARRAY_SIZE(mi->ringbuffer); n++)
+                               if (mi->ringbuffer[n].payload) {
+                                       free(mi->ringbuffer[n].payload);
+                                       mi->ringbuffer[n].payload = NULL;
                                }
-                               count_mi++;
-                               pmi = &(*pmi)->next;
-                       }
-               }
+
+                       free(mi);
+                       break;
+               } lws_end_foreach_llp(pmi, next);
 
                break;
 
@@ -257,12 +252,10 @@ done:
                 *  ask for WRITABLE callback for every wsi bound to this
                 * mirror instance
                 */
-
-               pss1 = pss->mi->same_mi_pss_list;
-               while (pss1) {
+               lws_start_foreach_ll(struct per_session_data__lws_mirror *,
+                                       pss1, pss->mi->same_mi_pss_list) {
                        lws_callback_on_writable(pss1->wsi);
-                       pss1 = pss1->same_mi_pss_list;
-               }
+               } lws_end_foreach_ll(pss1, same_mi_pss_list);
                break;
 
        default: