Add remove observer logic when delete resource.

In case of deleting resource using oc_delete_resource(),
add remove observer logic in delete resource logic.
If observer is not removed when delete resource, it will
occur crash when remove every observers from shutdown(because
observer has resource pointer in their member struct).

Change-Id: Ic71b90b76fce43df2ca7d8aa2a3904d892959044
Signed-off-by: Jaehyun Cho <jaehyun3.cho@samsung.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/26575
Tested-by: IoTivity Jenkins <jenkins-daemon@iotivity.org>
Reviewed-by: Jaehong Jo <jaehong.jo@samsung.com>
Reviewed-by: Kishen Maloor <kishen.maloor@intel.com>

api/oc_ri.c

@@ -316,6 +316,9 @@ oc_ri_delete_resource(oc_resource_t *resource)
   if (!resource)
     return false;
 
+  if (resource->num_observers > 0) {
+    coap_remove_observer_by_resource(resource);
+  }
   oc_list_remove(app_resources, resource);
   oc_ri_free_resource_properties(resource);
   oc_memb_free(&app_resources_s, resource);

messaging/coap/observe.c

@@ -246,6 +246,26 @@ coap_remove_observer_by_mid(oc_endpoint_t *endpoint, uint16_t mid)
   OC_DBG("Removed %d observers", removed);
   return removed;
 }
+/*---------------------------------------------------------------------------*/
+int
+coap_remove_observer_by_resource(const oc_resource_t *rsc)
+{
+  int removed = 0;
+  coap_observer_t *obs = (coap_observer_t *)oc_list_head(observers_list), *next;
+
+  while (obs) {
+    next = obs->next;
+    if ((obs->resource == rsc) && (oc_string(rsc->uri) &&
+                                   memcmp(obs->url, oc_string(rsc->uri) + 1,
+                                          oc_string_len(rsc->uri) - 1) == 0)) {
+      obs->resource->num_observers--;
+      coap_remove_observer(obs);
+      removed++;
+    }
+    obs = next;
+  }
+  return removed;
+}
 
 /*---------------------------------------------------------------------------*/
 /*- Notification ------------------------------------------------------------*/

messaging/coap/observe.h

@@ -83,6 +83,7 @@ int coap_remove_observer_by_client(oc_endpoint_t *endpoint);
 int coap_remove_observer_by_token(oc_endpoint_t *endpoint, uint8_t *token,
                                   size_t token_len);
 int coap_remove_observer_by_mid(oc_endpoint_t *endpoint, uint16_t mid);
+int coap_remove_observer_by_resource(const oc_resource_t *rsc);
 void coap_free_all_observers(void);
 
 int coap_notify_observers(oc_resource_t *resource,