* add C examples

* change doxygen to output stuff in "doxygen/" instead of "doxygen-doc/"
* implement avahi_entry_group_{reset,is_empty}() and make everyone use it
* move holdoff (SLEEPING) time checking from server to entry group
* add preliminary error codes


git-svn-id: file:///home/lennart/svn/public/avahi/trunk@216 941a03a8-eaeb-0310-b9a0-b1bbd8fe43fe

6 files changed, 207 insertions, 97 deletions

diff --git a/avahi-core/avahi-test.c b/avahi-core/avahi-test.c
index d91e698..cc950d4 100644
--- a/avahi-core/avahi-test.c
+++ b/avahi-core/avahi-test.c
@@ -101,16 +101,18 @@ static void server_callback(AvahiServer *s, AvahiServerState state, gpointer use
 
 static void remove_entries(void) {
     if (group)
-        avahi_entry_group_free(group);
-
-    group = NULL;
+        avahi_entry_group_reset(group);
 }
 
 static void create_entries(gboolean new_name) {
     AvahiAddress a;
+
     remove_entries();
-    
-    group = avahi_entry_group_new(server, entry_group_callback, NULL);   
+
+    if (!group) 
+        group = avahi_entry_group_new(server, entry_group_callback, NULL);
+
+    g_assert(avahi_entry_group_is_empty(group));
     
     if (!service_name)
         service_name = g_strdup("Test Service");
diff --git a/avahi-core/conformance-test.c b/avahi-core/conformance-test.c
index f8e0c93..ccc9a12 100644
--- a/avahi-core/conformance-test.c
+++ b/avahi-core/conformance-test.c
@@ -56,17 +56,15 @@ static void create_service(const gchar *t) {
 
     g_assert(t || name);
 
-    if (group)
-        avahi_entry_group_free(group);
-    
     n = t ? g_strdup(t) : avahi_alternative_service_name(name);
     g_free(name);
     name = n;
 
-    if (try > 10)
-        sleep(2); /* ugly ugly ugly hack */
+    if (group)
+        avahi_entry_group_reset(group);
+    else
+        group = avahi_entry_group_new(avahi, entry_group_callback, NULL);
     
-    group = avahi_entry_group_new(avahi, entry_group_callback, NULL);   
     avahi_server_add_service(avahi, group, 0, AF_UNSPEC, name, "_http._tcp", NULL, NULL, 80, "foo", NULL);   
     avahi_entry_group_commit(group);
 
@@ -94,14 +92,17 @@ static void entry_group_callback(AvahiServer *s, AvahiEntryGroup *g, AvahiEntryG
 
 static void server_callback(AvahiServer *s, AvahiServerState state, gpointer userdata) {
     avahi_log_debug("server state: %i", state);
+
+    if (state == AVAHI_SERVER_RUNNING) {
+        create_service("gurke");
+        avahi_server_dump(avahi, dump_line, NULL);
+    }
 }
 
 int main(int argc, char *argv[]) {
     GMainLoop *loop = NULL;
 
     avahi = avahi_server_new(NULL, NULL, server_callback, NULL);
-    create_service("gurke");
-    avahi_server_dump(avahi, dump_line, NULL);
     
     loop = g_main_loop_new(NULL, FALSE);
     g_timeout_add(1000*5, dump_timeout, avahi);
@@ -109,7 +110,8 @@ int main(int argc, char *argv[]) {
     g_main_loop_run(loop);
     g_main_loop_unref(loop);
 
-    avahi_entry_group_free(group);   
+    if (group)
+        avahi_entry_group_free(group);   
     avahi_server_free(avahi);
     
     return 0;
diff --git a/avahi-core/core.h b/avahi-core/core.h
index bacb97e..aa6b809 100644
--- a/avahi-core/core.h
+++ b/avahi-core/core.h
@@ -26,6 +26,13 @@
 
 /** \file core.h The Avahi Multicast DNS and DNS Service Discovery implmentation. */
 
+/** \example publish-service.c Example how to register a DNS-SD
+ * service using an embedded mDNS stack. It behaves like a network
+ * printer registering both an IPP and a BSD LPR service. */
+
+/** \example browse-services.c Example how to browse for DNS-SD
+ * services using an embedded mDNS stack. */
+
 #include <avahi-common/cdecl.h>
 
 AVAHI_C_DECL_BEGIN
@@ -47,13 +54,19 @@ AVAHI_C_DECL_END
 
 AVAHI_C_DECL_BEGIN
 
+/** Error codes used by avahi */
+enum { 
+    AVAHI_OK = 0,                      /**< OK */
+    AVAHI_ERR_FAILURE = -1,            /**< Generic error code */
+    AVAHI_ERR_BAD_STATE = -2           /**< Object was in a bad state */
+};
+
 /** States of a server object */
 typedef enum {
     AVAHI_SERVER_INVALID = -1,     /**< Invalid state (initial) */ 
     AVAHI_SERVER_REGISTERING = 0,  /**< Host RRs are being registered */
     AVAHI_SERVER_RUNNING,          /**< All host RRs have been established */
-    AVAHI_SERVER_COLLISION,        /**< There is a collision with a host RR. All host RRs have been withdrawn, the user should set a new host name via avahi_server_set_host_name() */
-    AVAHI_SERVER_SLEEPING          /**< The host or domain name has changed and the server waits for old entries to be expired */
+    AVAHI_SERVER_COLLISION         /**< There is a collision with a host RR. All host RRs have been withdrawn, the user should set a new host name via avahi_server_set_host_name() */
 } AvahiServerState;
 
 /** Flags for server entries */
@@ -70,7 +83,8 @@ typedef enum {
     AVAHI_ENTRY_GROUP_UNCOMMITED = -1,   /**< The group has not yet been commited, the user must still call avahi_entry_group_commit() */
     AVAHI_ENTRY_GROUP_REGISTERING = 0,   /**< The entries of the group are currently being registered */
     AVAHI_ENTRY_GROUP_ESTABLISHED,       /**< The entries have successfully been established */
-    AVAHI_ENTRY_GROUP_COLLISION          /**< A name collision for one of the entries in the group has been detected, the entries have been withdrawn */ 
+    AVAHI_ENTRY_GROUP_COLLISION,          /**< A name collision for one of the entries in the group has been detected, the entries have been withdrawn */ 
+    AVAHI_ENTRY_GROUP_SLEEPING           /**< Rate limiting of probe packets is active */
 } AvahiEntryGroupState;
 
 /** Prototype for callback functions which are called whenever the state of an AvahiServer object changes */
@@ -189,6 +203,12 @@ void avahi_entry_group_free(AvahiEntryGroup *g);
 /** Commit an entry group. This starts the probing and registration process for all RRs in the group */
 gint avahi_entry_group_commit(AvahiEntryGroup *g);
 
+/** Remove all entries from the entry group and reset the state to AVAHI_ENTRY_GROUP_UNCOMMITED. */
+void avahi_entry_group_reset(AvahiEntryGroup *g);
+
+/** Return TRUE if the entry group is empty, i.e. has no records attached. */
+gboolean avahi_entry_group_is_empty(AvahiEntryGroup *g);
+
 /** Return the current state of the specified entry group */
 AvahiEntryGroupState avahi_entry_group_get_state(AvahiEntryGroup *g);
 
diff --git a/avahi-core/iface.c b/avahi-core/iface.c
index ad26ab0..4376008 100644
--- a/avahi-core/iface.c
+++ b/avahi-core/iface.c
@@ -50,24 +50,31 @@ static void update_address_rr(AvahiInterfaceMonitor *m, AvahiInterfaceAddress *a
         (m->server->state == AVAHI_SERVER_RUNNING ||
         m->server->state == AVAHI_SERVER_REGISTERING)) {
 
-        if (!a->entry_group) {
+        /* Fill the entry group */
+        if (!a->entry_group) 
             a->entry_group = avahi_entry_group_new(m->server, avahi_host_rr_entry_group_callback, NULL);
+
+        if (avahi_entry_group_is_empty(a->entry_group)) {
+
             if (avahi_server_add_address(m->server, a->entry_group, a->interface->hardware->index, a->interface->protocol, 0, NULL, &a->address) < 0) {
                 avahi_log_warn(__FILE__": avahi_server_add_address() failed.");
                 avahi_entry_group_free(a->entry_group);
                 a->entry_group = NULL;
-            } else
-                avahi_entry_group_commit(a->entry_group);
+                return;
+            }
+
+            avahi_entry_group_commit(a->entry_group);
         }
     } else {
 
-        if (a->entry_group) {
+        /* Clear the entry group */
+
+        if (a->entry_group && !avahi_entry_group_is_empty(a->entry_group)) {
 
             if (avahi_entry_group_get_state(a->entry_group) == AVAHI_ENTRY_GROUP_REGISTERING)
                 avahi_server_decrease_host_rr_pending(m->server);
             
-            avahi_entry_group_free(a->entry_group);
-            a->entry_group = NULL;
+            avahi_entry_group_reset(a->entry_group);
         }
     } 
 }
@@ -96,13 +103,16 @@ static void update_hw_interface_rr(AvahiInterfaceMonitor *m, AvahiHwInterface *h
         (m->server->state == AVAHI_SERVER_RUNNING ||
         m->server->state == AVAHI_SERVER_REGISTERING)) {
 
-        if (!hw->entry_group) {
+        if (!hw->entry_group)
+            hw->entry_group = avahi_entry_group_new(m->server, avahi_host_rr_entry_group_callback, NULL);
+
+        if (avahi_entry_group_is_empty(hw->entry_group)) {
             gchar *name;
             gchar *t = avahi_format_mac_address(hw->mac_address, hw->mac_address_size);
+            
             name = g_strdup_printf("%s [%s]", m->server->host_name, t);
             g_free(t);
             
-            hw->entry_group = avahi_entry_group_new(m->server, avahi_host_rr_entry_group_callback, NULL);
             if (avahi_server_add_service(m->server, hw->entry_group, hw->index, AVAHI_PROTO_UNSPEC, name, "_workstation._tcp", NULL, NULL, 9, NULL) < 0) { 
                 avahi_log_warn(__FILE__": avahi_server_add_service() failed.");
                 avahi_entry_group_free(hw->entry_group);
@@ -115,13 +125,12 @@ static void update_hw_interface_rr(AvahiInterfaceMonitor *m, AvahiHwInterface *h
         
     } else {
 
-        if (hw->entry_group) {
+        if (hw->entry_group && !avahi_entry_group_is_empty(hw->entry_group)) {
 
             if (avahi_entry_group_get_state(hw->entry_group) == AVAHI_ENTRY_GROUP_REGISTERING)
                 avahi_server_decrease_host_rr_pending(m->server);
 
-            avahi_entry_group_free(hw->entry_group);
-            hw->entry_group = NULL;
+            avahi_entry_group_reset(hw->entry_group);
         }
     }
 }
@@ -133,6 +142,9 @@ static void free_address(AvahiInterfaceMonitor *m, AvahiInterfaceAddress *a) {
 
     update_address_rr(m, a, TRUE);
     AVAHI_LLIST_REMOVE(AvahiInterfaceAddress, address, a->interface->addresses, a);
+
+    if (a->entry_group)
+        avahi_entry_group_free(a->entry_group);
     
     g_free(a);
 }
@@ -171,6 +183,9 @@ static void free_hw_interface(AvahiInterfaceMonitor *m, AvahiHwInterface *hw, gb
     while (hw->interfaces)
         free_interface(m, hw->interfaces, send_goodbye);
 
+    if (hw->entry_group)
+        avahi_entry_group_free(hw->entry_group);
+    
     AVAHI_LLIST_REMOVE(AvahiHwInterface, hardware, m->hw_interfaces, hw);
     g_hash_table_remove(m->hash_table, &hw->index);
 
@@ -305,7 +320,7 @@ static void netlink_callback(AvahiNetlink *nl, struct nlmsghdr *n, gpointer user
             hw->name = NULL;
             hw->flags = 0;
             hw->mtu = 1500;
-            hw->index = ifinfomsg->ifi_index;
+            hw->index = (AvahiIfIndex) ifinfomsg->ifi_index;
             hw->mac_address_size = 0;
             hw->entry_group = NULL;
 
@@ -363,7 +378,7 @@ static void netlink_callback(AvahiNetlink *nl, struct nlmsghdr *n, gpointer user
         if (ifinfomsg->ifi_family != AF_UNSPEC)
             return;
         
-        if (!(hw = avahi_interface_monitor_get_hw_interface(m, ifinfomsg->ifi_index)))
+        if (!(hw = avahi_interface_monitor_get_hw_interface(m, (AvahiIfIndex) ifinfomsg->ifi_index)))
             return;
 
         update_hw_interface_rr(m, hw, TRUE);
@@ -381,10 +396,10 @@ static void netlink_callback(AvahiNetlink *nl, struct nlmsghdr *n, gpointer user
         if (ifaddrmsg->ifa_family != AVAHI_PROTO_INET && ifaddrmsg->ifa_family != AVAHI_PROTO_INET6)
             return;
 
-        if (!(i = (AvahiInterface*) avahi_interface_monitor_get_interface(m, ifaddrmsg->ifa_index, ifaddrmsg->ifa_family)))
+        if (!(i = (AvahiInterface*) avahi_interface_monitor_get_interface(m, (AvahiIfIndex) ifaddrmsg->ifa_index, (AvahiProtocol) ifaddrmsg->ifa_family)))
             return;
 
-        raddr.family = ifaddrmsg->ifa_family;
+        raddr.family = (AvahiProtocol) ifaddrmsg->ifa_family;
 
         l = NLMSG_PAYLOAD(n, sizeof(struct ifaddrmsg));
         a = IFA_RTA(ifaddrmsg);
diff --git a/avahi-core/server.c b/avahi-core/server.c
index 4507aea..e3929db 100644
--- a/avahi-core/server.c
+++ b/avahi-core/server.c
@@ -38,7 +38,9 @@
 #include "browse.h"
 #include "log.h"
 
-#define AVAHI_HOST_RR_HOLDOFF_MSEC 2000
+#define AVAHI_RR_HOLDOFF_MSEC 1000
+#define AVAHI_RR_HOLDOFF_MSEC_RATE_LIMIT 60000
+#define AVAHI_RR_RATE_LIMIT_COUNT 15
 
 static void free_entry(AvahiServer*s, AvahiEntry *e) {
     AvahiEntry *t;
@@ -74,6 +76,9 @@ static void free_group(AvahiServer *s, AvahiEntryGroup *g) {
     while (g->entries)
         free_entry(s, g->entries);
 
+    if (g->register_time_event)
+        avahi_time_event_queue_remove(s->time_event_queue, g->register_time_event);
+    
     AVAHI_LLIST_REMOVE(AvahiEntryGroup, groups, s->groups, g);
     g_free(g);
 }
@@ -192,10 +197,14 @@ static void withdraw_entry(AvahiServer *s, AvahiEntry *e) {
         AvahiEntry *k;
         
         for (k = e->group->entries; k; k = k->by_group_next) {
-            avahi_goodbye_entry(s, k, FALSE);
-            k->dead = TRUE;
+            if (!k->dead) {
+                avahi_goodbye_entry(s, k, FALSE);
+                k->dead = TRUE;
+            }
         }
-        
+
+        e->group->n_probing = 0;
+
         avahi_entry_group_change_state(e->group, AVAHI_ENTRY_GROUP_COLLISION);
     } else {
         avahi_goodbye_entry(s, e, FALSE);
@@ -763,7 +772,7 @@ static void reflect_legacy_unicast_query_packet(AvahiServer *s, AvahiDnsPacket *
     if (!s->config.enable_reflector)
         return;
 
-/*     avahi_log_debug("legacy unicast reflectr"); */
+/*     avahi_log_debug("legacy unicast reflector"); */
     
     /* Reflecting legacy unicast queries is a little more complicated
        than reflecting normal queries, since we must route the
@@ -1090,15 +1099,11 @@ static void server_set_state(AvahiServer *s, AvahiServerState state) {
 static void withdraw_host_rrs(AvahiServer *s) {
     g_assert(s);
 
-    if (s->hinfo_entry_group) {
-        avahi_entry_group_free(s->hinfo_entry_group);
-        s->hinfo_entry_group = NULL;
-    }
+    if (s->hinfo_entry_group)
+        avahi_entry_group_reset(s->hinfo_entry_group);
 
-    if (s->browse_domain_entry_group) {
-        avahi_entry_group_free(s->browse_domain_entry_group);
-        s->browse_domain_entry_group = NULL;
-    }
+    if (s->browse_domain_entry_group)
+        avahi_entry_group_reset(s->browse_domain_entry_group);
 
     avahi_update_host_rrs(s->monitor, TRUE);
     s->n_host_rr_pending = 0;
@@ -1141,10 +1146,13 @@ static void register_hinfo(AvahiServer *s) {
     
     g_assert(s);
     
-    if (!s->config.publish_hinfo || s->hinfo_entry_group)
+    if (!s->config.publish_hinfo)
         return;
-    
-    s->hinfo_entry_group = avahi_entry_group_new(s, avahi_host_rr_entry_group_callback, NULL);
+
+    if (s->hinfo_entry_group)
+        g_assert(avahi_entry_group_is_empty(s->hinfo_entry_group));
+    else
+        s->hinfo_entry_group = avahi_entry_group_new(s, avahi_host_rr_entry_group_callback, NULL);
     
     /* Fill in HINFO rr */
     r = avahi_record_new_full(s->host_name_fqdn, AVAHI_DNS_CLASS_IN, AVAHI_DNS_TYPE_HINFO, AVAHI_DEFAULT_TTL_HOST_NAME);
@@ -1172,10 +1180,14 @@ static void register_localhost(AvahiServer *s) {
 static void register_browse_domain(AvahiServer *s) {
     g_assert(s);
 
-    if (!s->config.publish_domain || s->browse_domain_entry_group)
+    if (!s->config.publish_domain)
         return;
 
-    s->browse_domain_entry_group = avahi_entry_group_new(s, NULL, NULL);
+    if (s->browse_domain_entry_group)
+        g_assert(avahi_entry_group_is_empty(s->browse_domain_entry_group));
+    else
+        s->browse_domain_entry_group = avahi_entry_group_new(s, NULL, NULL);
+    
     avahi_server_add_ptr(s, s->browse_domain_entry_group, AVAHI_IF_UNSPEC, AVAHI_PROTO_UNSPEC, 0, AVAHI_DEFAULT_TTL, "b._dns-sd._udp.local", s->domain_name);
     avahi_entry_group_commit(s->browse_domain_entry_group);
 }
@@ -1202,38 +1214,10 @@ static void update_fqdn(AvahiServer *s) {
     s->host_name_fqdn = g_strdup_printf("%s.%s", s->host_name, s->domain_name);
 }
 
-static void register_time_event_callback(AvahiTimeEvent *e, gpointer userdata) {
-    AvahiServer *s = userdata;
-    
-    g_assert(e);
-    g_assert(s);
-
-    g_assert(e == s->register_time_event);
-    avahi_time_event_queue_remove(s->time_event_queue, s->register_time_event);
-    s->register_time_event = NULL;
-
-    if (s->state == AVAHI_SERVER_SLEEPING)
-        register_stuff(s);
-}
-
-static void delayed_register_stuff(AvahiServer *s) {
-    GTimeVal tv;
-    
-    g_assert(s);
-
-    avahi_elapse_time(&tv, AVAHI_HOST_RR_HOLDOFF_MSEC, 0);
-
-    if (s->register_time_event)
-        avahi_time_event_queue_update(s->time_event_queue, s->register_time_event, &tv);
-    else
-        s->register_time_event = avahi_time_event_queue_add(s->time_event_queue, &tv, register_time_event_callback, s);
-}
-
 gint avahi_server_set_host_name(AvahiServer *s, const gchar *host_name) {
     g_assert(s);
     g_assert(host_name);
 
-    server_set_state(s, AVAHI_SERVER_SLEEPING);
     withdraw_host_rrs(s);
 
     g_free(s->host_name);
@@ -1241,26 +1225,24 @@ gint avahi_server_set_host_name(AvahiServer *s, const gchar *host_name) {
     s->host_name[strcspn(s->host_name, ".")] = 0;
     update_fqdn(s);
 
-    delayed_register_stuff(s);
-    return 0;
+    register_stuff(s);
+    return AVAHI_OK;
 }
 
 gint avahi_server_set_domain_name(AvahiServer *s, const gchar *domain_name) {
     g_assert(s);
     g_assert(domain_name);
 
-    server_set_state(s, AVAHI_SERVER_SLEEPING);
     withdraw_host_rrs(s);
 
     g_free(s->domain_name);
     s->domain_name = domain_name ? avahi_normalize_name(domain_name) : g_strdup("local");
     update_fqdn(s);
 
-    delayed_register_stuff(s);
-    return 0;
+    register_stuff(s);
+    return AVAHI_OK;
 }
 
-
 static void prepare_pollfd(AvahiServer *s, GPollFD *pollfd, gint fd) {
     g_assert(s);
     g_assert(pollfd);
@@ -1358,7 +1340,6 @@ AvahiServer *avahi_server_new(GMainContext *c, const AvahiServerConfig *sc, Avah
     s->record_list = avahi_record_list_new();
 
     s->time_event_queue = avahi_time_event_queue_new(s->context, G_PRIORITY_DEFAULT+10); /* Slightly less priority than the FDs */
-    s->register_time_event = NULL;
     
     s->state = AVAHI_SERVER_INVALID;
 
@@ -1407,8 +1388,6 @@ void avahi_server_free(AvahiServer* s) {
 
     g_hash_table_destroy(s->entries_by_key);
 
-    if (s->register_time_event)
-        avahi_time_event_queue_remove(s->time_event_queue, s->register_time_event);
     avahi_time_event_queue_free(s->time_event_queue);
 
     avahi_record_list_free(s->record_list);
@@ -1984,6 +1963,10 @@ AvahiEntryGroup *avahi_entry_group_new(AvahiServer *s, AvahiEntryGroupCallback c
     g->dead = FALSE;
     g->state = AVAHI_ENTRY_GROUP_UNCOMMITED;
     g->n_probing = 0;
+    g->n_register_try = 0;
+    g->register_time_event = NULL;
+    g->register_time.tv_sec = 0;
+    g->register_time.tv_usec = 0;
     AVAHI_LLIST_HEAD_INIT(AvahiEntry, g->entries);
 
     AVAHI_LLIST_PREPEND(AvahiEntryGroup, groups, s->groups, g);
@@ -1997,8 +1980,15 @@ void avahi_entry_group_free(AvahiEntryGroup *g) {
     g_assert(g->server);
 
     for (e = g->entries; e; e = e->by_group_next) {
-        avahi_goodbye_entry(g->server, e, TRUE);
-        e->dead = TRUE;
+        if (!e->dead) {
+            avahi_goodbye_entry(g->server, e, TRUE);
+            e->dead = TRUE;
+        }
+    }
+
+    if (g->register_time_event) {
+        avahi_time_event_queue_remove(g->server->time_event_queue, g->register_time_event);
+        g->register_time_event = NULL;
     }
 
     g->dead = TRUE;
@@ -2007,18 +1997,85 @@ void avahi_entry_group_free(AvahiEntryGroup *g) {
     g->server->need_entry_cleanup = TRUE;
 }
 
-gint avahi_entry_group_commit(AvahiEntryGroup *g) {
+static void entry_group_commit_real(AvahiEntryGroup *g) {
     g_assert(g);
-    g_assert(!g->dead);
-
-    if (g->state != AVAHI_ENTRY_GROUP_UNCOMMITED)
-        return -1;
 
     avahi_entry_group_change_state(g, AVAHI_ENTRY_GROUP_REGISTERING);
     avahi_announce_group(g->server, g);
     avahi_entry_group_check_probed(g, FALSE);
 
-    return 0;
+    g_get_current_time(&g->register_time);
+}
+
+static void entry_group_register_time_event_callback(AvahiTimeEvent *e, gpointer userdata) {
+    AvahiEntryGroup *g = userdata;
+    g_assert(g);
+
+    avahi_log_debug("Holdoff passed, waking up and going on.");
+
+    avahi_time_event_queue_remove(g->server->time_event_queue, g->register_time_event);
+    g->register_time_event = NULL;
+    
+    /* Holdoff time passed, so let's start probing */
+    entry_group_commit_real(g);
+}
+
+gint avahi_entry_group_commit(AvahiEntryGroup *g) {
+    GTimeVal now;
+    
+    g_assert(g);
+    g_assert(!g->dead);
+
+    if (g->state != AVAHI_ENTRY_GROUP_UNCOMMITED && g->state != AVAHI_ENTRY_GROUP_COLLISION)
+        return AVAHI_ERR_BAD_STATE;
+
+    g->n_register_try++;
+
+    avahi_timeval_add(&g->register_time,
+                      1000*(g->n_register_try >= AVAHI_RR_RATE_LIMIT_COUNT ?
+                            AVAHI_RR_HOLDOFF_MSEC_RATE_LIMIT :
+                            AVAHI_RR_HOLDOFF_MSEC));
+
+    g_get_current_time(&now);
+
+    if (avahi_timeval_compare(&g->register_time, &now) <= 0) {
+        /* Holdoff time passed, so let's start probing */
+        avahi_log_debug("Holdoff passed, directly going on.");
+
+        entry_group_commit_real(g);
+    } else {
+        avahi_log_debug("Holdoff not passed, sleeping.");
+
+        /* Holdoff time has not yet passed, so let's wait */
+        avahi_entry_group_change_state(g, AVAHI_ENTRY_GROUP_SLEEPING);
+        
+        g_assert(!g->register_time_event);
+        g->register_time_event = avahi_time_event_queue_add(g->server->time_event_queue, &g->register_time, entry_group_register_time_event_callback, g);
+    }
+
+    return AVAHI_OK;
+}
+
+void avahi_entry_group_reset(AvahiEntryGroup *g) {
+    AvahiEntry *e;
+    g_assert(g);
+    
+    if (g->register_time_event) {
+        avahi_time_event_queue_remove(g->server->time_event_queue, g->register_time_event);
+        g->register_time_event = NULL;
+    }
+    
+    for (e = g->entries; e; e = e->by_group_next) {
+        if (!e->dead) {
+            avahi_goodbye_entry(g->server, e, TRUE);
+            e->dead = TRUE;
+        }
+    }
+    
+    g->server->need_entry_cleanup = TRUE;
+    g->n_probing = 0;
+
+    avahi_entry_group_change_state(g, AVAHI_ENTRY_GROUP_UNCOMMITED);
 }
 
 gboolean avahi_entry_commited(AvahiEntry *e) {
@@ -2049,6 +2106,18 @@ gpointer avahi_entry_group_get_data(AvahiEntryGroup *g) {
     return g->userdata;
 }
 
+gboolean avahi_entry_group_is_empty(AvahiEntryGroup *g) {
+    AvahiEntry *e;
+    g_assert(g);
+
+    /* Look for an entry that is not dead */
+    for (e = g->entries; e; e = e->by_group_next)
+        if (!e->dead)
+            return FALSE;
+
+    return TRUE;
+}
+
 const gchar* avahi_server_get_domain_name(AvahiServer *s) {
     g_assert(s);
 
diff --git a/avahi-core/server.h b/avahi-core/server.h
index 97febc5..7049f58 100644
--- a/avahi-core/server.h
+++ b/avahi-core/server.h
@@ -75,6 +75,10 @@ struct AvahiEntryGroup {
 
     guint n_probing;
     
+    guint n_register_try;
+    GTimeVal register_time;
+    AvahiTimeEvent *register_time_event;
+    
     AVAHI_LLIST_FIELDS(AvahiEntryGroup, groups);
     AVAHI_LLIST_HEAD(AvahiEntry, entries);
 };
@@ -121,8 +125,6 @@ struct AvahiServer {
     AvahiEntryGroup *browse_domain_entry_group;
     guint n_host_rr_pending;
 
-    AvahiTimeEvent *register_time_event;
-    
     /* Used for assembling responses */
     AvahiRecordList *record_list;