diff --git a/src/core/ddsc/include/dds/dds.h b/src/core/ddsc/include/dds/dds.h
index 6c9ae53..a6f7f73 100644
--- a/src/core/ddsc/include/dds/dds.h
+++ b/src/core/ddsc/include/dds/dds.h
@@ -755,11 +755,8 @@ dds_create_participant(
  * @param[in]  domain The domain to be created. DEFAULT_DOMAIN is not allowed.
  * @param[in]  config A configuration string containing file names and/or XML fragments representing the configuration.
  *
- * @returns A return code
+ * @returns A valid entity handle or an error code.
  *
- * @retval DDS_RETCODE_OK
- *             The domain with the domain identifier has been created from
- *             given configuration string.
  * @retval DDS_RETCODE_BAD_PARAMETER
  *             Illegal value for domain id or the configfile parameter is NULL.
  * @retval DDS_PRECONDITION_NOT_MET
@@ -767,7 +764,7 @@ dds_create_participant(
  * @retval DDS_RETCODE_ERROR
  *             An internal error has occurred.
  */
-DDS_EXPORT dds_return_t
+DDS_EXPORT dds_entity_t
 dds_create_domain(const dds_domainid_t domain, const char *config);
 
 /**
diff --git a/src/core/ddsc/src/dds__domain.h b/src/core/ddsc/src/dds__domain.h
index db5d7bc..4719440 100644
--- a/src/core/ddsc/src/dds__domain.h
+++ b/src/core/ddsc/src/dds__domain.h
@@ -18,7 +18,7 @@
 extern "C" {
 #endif
 
-DDS_EXPORT dds_return_t dds_domain_create_internal (dds_domain **domain_out, dds_domainid_t id, bool use_existing, const char *config) ddsrt_nonnull((1,4));
+DDS_EXPORT dds_entity_t dds_domain_create_internal (dds_domain **domain_out, dds_domainid_t id, bool implicit, const char *config) ddsrt_nonnull((1,4));
 DDS_EXPORT dds_domain *dds_domain_find_locked (dds_domainid_t id);
 
 #if defined (__cplusplus)
diff --git a/src/core/ddsc/src/dds__entity.h b/src/core/ddsc/src/dds__entity.h
index 8f4e34c..3725d83 100644
--- a/src/core/ddsc/src/dds__entity.h
+++ b/src/core/ddsc/src/dds__entity.h
@@ -24,6 +24,7 @@ dds_entity_init(
   dds_entity * e,
   dds_entity * parent,
   dds_entity_kind_t kind,
+  bool implicit,
   dds_qos_t * qos,
   const dds_listener_t *listener,
   status_mask_t mask);
@@ -38,6 +39,12 @@ dds_entity_register_child (
 DDS_EXPORT void
 dds_entity_add_ref_locked(dds_entity *e);
 
+DDS_EXPORT void
+dds_entity_drop_ref(dds_entity *e);
+
+DDS_EXPORT void
+dds_entity_unpin_and_drop_ref (dds_entity *e);
+
 #define DEFINE_ENTITY_LOCK_UNLOCK(qualifier_, type_, kind_) \
   qualifier_ dds_return_t type_##_lock (dds_entity_t hdl, type_ **x) \
   { \
@@ -96,6 +103,8 @@ dds_entity_pin (
   dds_entity_t hdl,
   dds_entity **eptr);
 
+DDS_EXPORT dds_return_t dds_entity_pin_for_delete (dds_entity_t hdl, bool explicit, dds_entity **eptr);
+
 DDS_EXPORT void dds_entity_unpin (
   dds_entity *e);
 
diff --git a/src/core/ddsc/src/dds__handles.h b/src/core/ddsc/src/dds__handles.h
index de7d2cd..db85ce7 100644
--- a/src/core/ddsc/src/dds__handles.h
+++ b/src/core/ddsc/src/dds__handles.h
@@ -72,9 +72,11 @@ typedef int32_t dds_handle_t;
 
 /* Closing & closed can be combined, but having two gives a means for enforcing
    that close() be called first, then close_wait(), and then delete(). */
-#define HDL_FLAG_CLOSING   (0x80000000u)
-#define HDL_FLAG_CLOSED    (0x40000000u)
-#define HDL_FLAG_PENDING   (0x20000000u)
+#define HDL_FLAG_CLOSING         (0x80000000u)
+#define HDL_FLAG_DELETE_DEFERRED (0x40000000u)
+#define HDL_FLAG_PENDING         (0x20000000u)
+#define HDL_FLAG_IMPLICIT        (0x10000000u)
+#define HDL_FLAG_ALLOW_CHILDREN  (0x08000000u) /* refc counts children */
 
 struct dds_handle_link {
   dds_handle_t hdl;
@@ -116,7 +118,9 @@ dds_handle_server_fini(void);
  */
 DDS_EXPORT dds_handle_t
 dds_handle_create(
-        struct dds_handle_link *link);
+        struct dds_handle_link *link,
+        bool implicit,
+        bool allow_children);
 
 
 /*
@@ -124,7 +128,7 @@ dds_handle_create(
  */
 DDS_EXPORT dds_return_t
 dds_handle_register_special (
-        struct dds_handle_link *link, dds_handle_t handle);
+        struct dds_handle_link *link, bool implicit, bool allow_children, dds_handle_t handle);
 
 DDS_EXPORT void dds_handle_unpend (struct dds_handle_link *link);
 
@@ -181,6 +185,8 @@ DDS_EXPORT void
 dds_handle_unpin(
         struct dds_handle_link *link);
 
+int32_t dds_handle_pin_for_delete (dds_handle_t hdl, bool explicit, struct dds_handle_link **link);
+bool dds_handle_drop_childref_and_pin (struct dds_handle_link *link, bool may_delete_parent);
 
 /*
  * Check if the handle is closed.
@@ -195,11 +201,15 @@ dds_handle_unpin(
 
 DDS_EXPORT void dds_handle_add_ref (struct dds_handle_link *link);
 DDS_EXPORT bool dds_handle_drop_ref (struct dds_handle_link *link);
+DDS_EXPORT bool dds_handle_close (struct dds_handle_link *link);
+DDS_EXPORT bool dds_handle_unpin_and_drop_ref (struct dds_handle_link *link);
 
 DDS_EXPORT inline bool dds_handle_is_closed (struct dds_handle_link *link) {
-  return (ddsrt_atomic_ld32 (&link->cnt_flags) & (HDL_FLAG_CLOSED | HDL_FLAG_CLOSING)) != 0;
+  return (ddsrt_atomic_ld32 (&link->cnt_flags) & HDL_FLAG_CLOSING) != 0;
 }
 
+DDS_EXPORT bool dds_handle_is_not_refd (struct dds_handle_link *link);
+
 #if defined (__cplusplus)
 }
 #endif
diff --git a/src/core/ddsc/src/dds__publisher.h b/src/core/ddsc/src/dds__publisher.h
index 517abff..d1be193 100644
--- a/src/core/ddsc/src/dds__publisher.h
+++ b/src/core/ddsc/src/dds__publisher.h
@@ -21,6 +21,13 @@ extern "C" {
 
 DEFINE_ENTITY_LOCK_UNLOCK(inline, dds_publisher, DDS_KIND_PUBLISHER)
 
+dds_entity_t
+dds__create_publisher_l(
+  struct dds_participant *participant, /* entity-lock must be held */
+  bool implicit,
+  const dds_qos_t *qos,
+  const dds_listener_t *listener);
+
 dds_return_t dds_publisher_begin_coherent (dds_entity_t e);
 dds_return_t dds_publisher_end_coherent (dds_entity_t e);
 
diff --git a/src/core/ddsc/src/dds__subscriber.h b/src/core/ddsc/src/dds__subscriber.h
index 966f43e..f713dda 100644
--- a/src/core/ddsc/src/dds__subscriber.h
+++ b/src/core/ddsc/src/dds__subscriber.h
@@ -24,6 +24,7 @@ DEFINE_ENTITY_LOCK_UNLOCK(inline, dds_subscriber, DDS_KIND_SUBSCRIBER)
 dds_entity_t
 dds__create_subscriber_l(
   struct dds_participant *participant, /* entity-lock must be held */
+  bool implicit,
   const dds_qos_t *qos,
   const dds_listener_t *listener);
 
diff --git a/src/core/ddsc/src/dds__types.h b/src/core/ddsc/src/dds__types.h
index 7d65792..4b9eec5 100644
--- a/src/core/ddsc/src/dds__types.h
+++ b/src/core/ddsc/src/dds__types.h
@@ -245,7 +245,7 @@ typedef struct dds_participant {
 
 typedef struct dds_reader {
   struct dds_entity m_entity;
-  const struct dds_topic *m_topic;
+  struct dds_topic *m_topic;
   struct dds_rhc *m_rhc; /* aliases m_rd->rhc with a wider interface, FIXME: but m_rd owns it for resource management */
   struct reader *m_rd;
   bool m_data_on_readers;
@@ -265,7 +265,7 @@ typedef struct dds_reader {
 
 typedef struct dds_writer {
   struct dds_entity m_entity;
-  const struct dds_topic *m_topic;
+  struct dds_topic *m_topic;
   struct nn_xpack *m_xp;
   struct writer *m_wr;
   struct whc *m_whc; /* FIXME: ownership still with underlying DDSI writer (cos of DDSI built-in writers )*/
diff --git a/src/core/ddsc/src/dds_builtin.c b/src/core/ddsc/src/dds_builtin.c
index 5720f7d..5b1c71c 100644
--- a/src/core/ddsc/src/dds_builtin.c
+++ b/src/core/ddsc/src/dds_builtin.c
@@ -131,7 +131,7 @@ bool dds__validate_builtin_reader_qos (const dds_domain *dom, dds_entity_t topic
 static dds_entity_t dds__create_builtin_subscriber (dds_participant *participant)
 {
   dds_qos_t *qos = dds__create_builtin_qos ();
-  dds_entity_t sub = dds__create_subscriber_l (participant, qos, NULL);
+  dds_entity_t sub = dds__create_subscriber_l (participant, false, qos, NULL);
   dds_delete_qos (qos);
   return sub;
 }
diff --git a/src/core/ddsc/src/dds_domain.c b/src/core/ddsc/src/dds_domain.c
index feaed61..78028af 100644
--- a/src/core/ddsc/src/dds_domain.c
+++ b/src/core/ddsc/src/dds_domain.c
@@ -48,16 +48,14 @@ static int dds_domain_compare (const void *va, const void *vb)
 static const ddsrt_avl_treedef_t dds_domaintree_def = DDSRT_AVL_TREEDEF_INITIALIZER (
   offsetof (dds_domain, m_node), offsetof (dds_domain, m_id), dds_domain_compare, 0);
 
-static dds_return_t dds_domain_init (dds_domain *domain, dds_domainid_t domain_id, const char *config)
+static dds_return_t dds_domain_init (dds_domain *domain, dds_domainid_t domain_id, const char *config, bool implicit)
 {
-  dds_return_t ret = DDS_RETCODE_OK;
+  dds_entity_t domh;
   uint32_t len;
-  dds_entity_t domain_handle;
 
-  if ((domain_handle = dds_entity_init (&domain->m_entity, &dds_global.m_entity, DDS_KIND_DOMAIN, NULL, NULL, 0)) < 0)
-    return domain_handle;
+  if ((domh = dds_entity_init (&domain->m_entity, &dds_global.m_entity, DDS_KIND_DOMAIN, implicit, NULL, NULL, 0)) < 0)
+    return domh;
   domain->m_entity.m_domain = domain;
-  domain->m_entity.m_flags |= DDS_ENTITY_IMPLICIT;
   domain->m_entity.m_iid = ddsi_iid_gen ();
 
   domain->gv.tstart = now ();
@@ -90,7 +88,7 @@ static dds_return_t dds_domain_init (dds_domain *domain, dds_domainid_t domain_i
   if (domain->cfgst == NULL)
   {
     DDS_ILOG (DDS_LC_CONFIG, domain_id, "Failed to parse configuration\n");
-    ret = DDS_RETCODE_ERROR;
+    domh = DDS_RETCODE_ERROR;
     goto fail_config;
   }
 
@@ -100,14 +98,14 @@ static dds_return_t dds_domain_init (dds_domain *domain, dds_domainid_t domain_i
   if (rtps_config_prep (&domain->gv, domain->cfgst) != 0)
   {
     DDS_ILOG (DDS_LC_CONFIG, domain->m_id, "Failed to configure RTPS\n");
-    ret = DDS_RETCODE_ERROR;
+    domh = DDS_RETCODE_ERROR;
     goto fail_rtps_config;
   }
 
   if (rtps_init (&domain->gv) < 0)
   {
     DDS_ILOG (DDS_LC_CONFIG, domain->m_id, "Failed to initialize RTPS\n");
-    ret = DDS_RETCODE_ERROR;
+    domh = DDS_RETCODE_ERROR;
     goto fail_rtps_init;
   }
 
@@ -122,14 +120,14 @@ static dds_return_t dds_domain_init (dds_domain *domain, dds_domainid_t domain_i
       if (dds_global.threadmon == NULL)
       {
         DDS_ILOG (DDS_LC_CONFIG, domain->m_id, "Failed to create a thread liveliness monitor\n");
-        ret = DDS_RETCODE_OUT_OF_RESOURCES;
+        domh = DDS_RETCODE_OUT_OF_RESOURCES;
         goto fail_threadmon_new;
       }
       /* FIXME: thread properties */
       if (ddsi_threadmon_start (dds_global.threadmon, "threadmon") < 0)
       {
         DDS_ILOG (DDS_LC_ERROR, domain->m_id, "Failed to start the thread liveliness monitor\n");
-        ret = DDS_RETCODE_ERROR;
+        domh = DDS_RETCODE_ERROR;
         goto fail_threadmon_start;
       }
     }
@@ -159,14 +157,14 @@ static dds_return_t dds_domain_init (dds_domain *domain, dds_domainid_t domain_i
   if (rtps_start (&domain->gv) < 0)
   {
     DDS_ILOG (DDS_LC_CONFIG, domain->m_id, "Failed to start RTPS\n");
-    ret = DDS_RETCODE_ERROR;
+    domh = DDS_RETCODE_ERROR;
     goto fail_rtps_start;
   }
 
   if (domain->gv.config.liveliness_monitoring)
     ddsi_threadmon_register_domain (dds_global.threadmon, &domain->gv);
   dds_entity_init_complete (&domain->m_entity);
-  return DDS_RETCODE_OK;
+  return domh;
 
 fail_rtps_start:
   if (domain->gv.config.liveliness_monitoring && dds_global.threadmon_count == 1)
@@ -184,7 +182,7 @@ fail_rtps_config:
   config_fini (domain->cfgst);
 fail_config:
   dds_handle_delete (&domain->m_entity.m_hdllink);
-  return ret;
+  return domh;
 }
 
 dds_domain *dds_domain_find_locked (dds_domainid_t id)
@@ -192,10 +190,10 @@ dds_domain *dds_domain_find_locked (dds_domainid_t id)
   return ddsrt_avl_lookup (&dds_domaintree_def, &dds_global.m_domains, &id);
 }
 
-dds_return_t dds_domain_create_internal (dds_domain **domain_out, dds_domainid_t id, bool use_existing, const char *config)
+dds_entity_t dds_domain_create_internal (dds_domain **domain_out, dds_domainid_t id, bool implicit, const char *config)
 {
   struct dds_domain *dom;
-  dds_return_t ret;
+  dds_entity_t domh;
 
   /* FIXME: should perhaps lock parent object just like everywhere */
   ddsrt_mutex_lock (&dds_global.m_mutex);
@@ -203,60 +201,71 @@ dds_return_t dds_domain_create_internal (dds_domain **domain_out, dds_domainid_t
   if (id != DDS_DOMAIN_DEFAULT)
   {
     if ((dom = dds_domain_find_locked (id)) == NULL)
-      ret = DDS_RETCODE_NOT_FOUND;
+      domh = DDS_RETCODE_NOT_FOUND;
     else
-      ret = DDS_RETCODE_OK;
+      domh = dom->m_entity.m_hdllink.hdl;
   }
   else
   {
     if ((dom = ddsrt_avl_find_min (&dds_domaintree_def, &dds_global.m_domains)) != NULL)
-      ret = DDS_RETCODE_OK;
+      domh = dom->m_entity.m_hdllink.hdl;
     else
-      ret = DDS_RETCODE_NOT_FOUND;
+      domh = DDS_RETCODE_NOT_FOUND;
   }
 
-  switch (ret)
+  if (domh == DDS_RETCODE_NOT_FOUND)
   {
-    case DDS_RETCODE_OK:
-      if (!use_existing)
-      {
-        ret = DDS_RETCODE_PRECONDITION_NOT_MET;
-        break;
-      }
+    dom = dds_alloc (sizeof (*dom));
+    if ((domh = dds_domain_init (dom, id, config, implicit)) < 0)
+      dds_free (dom);
+    else
+    {
       ddsrt_mutex_lock (&dom->m_entity.m_mutex);
-      if (dds_handle_is_closed (&dom->m_entity.m_hdllink))
-      {
-        ddsrt_mutex_unlock (&dom->m_entity.m_mutex);
-        ddsrt_cond_wait (&dds_global.m_cond, &dds_global.m_mutex);
-        goto retry;
-      }
-      else
+      ddsrt_avl_insert (&dds_domaintree_def, &dds_global.m_domains, dom);
+      dds_entity_register_child (&dds_global.m_entity, &dom->m_entity);
+      if (implicit)
       {
         dds_entity_add_ref_locked (&dom->m_entity);
-        ddsrt_mutex_unlock (&dom->m_entity.m_mutex);
-        *domain_out = dom;
+        dds_handle_repin (&dom->m_entity.m_hdllink);
       }
-      break;
-    case DDS_RETCODE_NOT_FOUND:
-      dom = dds_alloc (sizeof (*dom));
-      if ((ret = dds_domain_init (dom, id, config)) < 0)
-        dds_free (dom);
-      else
+      ddsrt_mutex_unlock (&dom->m_entity.m_mutex);
+      *domain_out = dom;
+    }
+  }
+  else if (domh <= DDS_RETCODE_OK)
+  {
+    assert (0);
+    domh = DDS_RETCODE_ERROR;
+  }
+  else if (!implicit)
+  {
+    domh = DDS_RETCODE_PRECONDITION_NOT_MET;
+  }
+  else
+  {
+    ddsrt_mutex_lock (&dom->m_entity.m_mutex);
+    if (dds_handle_is_closed (&dom->m_entity.m_hdllink))
+    {
+      ddsrt_mutex_unlock (&dom->m_entity.m_mutex);
+      ddsrt_cond_wait (&dds_global.m_cond, &dds_global.m_mutex);
+      goto retry;
+    }
+    else
+    {
+      if (implicit)
       {
-        ddsrt_mutex_lock (&dom->m_entity.m_mutex);
-        ddsrt_avl_insert (&dds_domaintree_def, &dds_global.m_domains, dom);
-        dds_entity_register_child (&dds_global.m_entity, &dom->m_entity);
         dds_entity_add_ref_locked (&dom->m_entity);
-        ddsrt_mutex_unlock (&dom->m_entity.m_mutex);
-        *domain_out = dom;
+        dds_handle_repin (&dom->m_entity.m_hdllink);
       }
-      break;
+      ddsrt_mutex_unlock (&dom->m_entity.m_mutex);
+      *domain_out = dom;
+    }
   }
   ddsrt_mutex_unlock (&dds_global.m_mutex);
-  return ret;
+  return domh;
 }
 
-dds_return_t dds_create_domain(const dds_domainid_t domain, const char *config)
+dds_entity_t dds_create_domain (const dds_domainid_t domain, const char *config)
 {
   dds_domain *dom;
   dds_entity_t ret;
@@ -266,16 +275,10 @@ dds_return_t dds_create_domain(const dds_domainid_t domain, const char *config)
 
   /* Make sure DDS instance is initialized. */
   if ((ret = dds_init ()) < 0)
-    goto err_dds_init;
+    return ret;
 
-  if ((ret = dds_domain_create_internal (&dom, domain, false, config)) < 0)
-    goto err_domain_create;
-
-  return DDS_RETCODE_OK;
-
-err_domain_create:
-  dds_delete_impl_pinned (&dds_global.m_entity, DIS_EXPLICIT);
-err_dds_init:
+  ret = dds_domain_create_internal (&dom, domain, false, config);
+  dds_entity_unpin_and_drop_ref (&dds_global.m_entity);
   return ret;
 }
 
@@ -368,5 +371,5 @@ void dds_write_set_batch (bool enable)
     }
   }
   ddsrt_mutex_unlock (&dds_global.m_mutex);
-  dds_delete_impl_pinned (&dds_global.m_entity, DIS_EXPLICIT);
+  dds_entity_unpin_and_drop_ref (&dds_global.m_entity);
 }
diff --git a/src/core/ddsc/src/dds_entity.c b/src/core/ddsc/src/dds_entity.c
index 56a5ce4..4288f4b 100644
--- a/src/core/ddsc/src/dds_entity.c
+++ b/src/core/ddsc/src/dds_entity.c
@@ -80,11 +80,40 @@ const ddsrt_avl_treedef_t dds_entity_children_td = DDSRT_AVL_TREEDEF_INITIALIZER
 static void dds_entity_observers_signal (dds_entity *observed, uint32_t status);
 static void dds_entity_observers_signal_delete (dds_entity *observed);
 
+static dds_return_t dds_delete_impl (dds_entity_t entity, enum delete_impl_state delstate);
+static dds_return_t really_delete_pinned_closed_locked (struct dds_entity *e, enum delete_impl_state delstate);
+
 void dds_entity_add_ref_locked (dds_entity *e)
 {
   dds_handle_add_ref (&e->m_hdllink);
 }
 
+void dds_entity_drop_ref (dds_entity *e)
+{
+  if (dds_handle_drop_ref (&e->m_hdllink))
+  {
+    /* increment pin count unconditionally to satisfy the "pinned" requirement */
+    dds_handle_repin (&e->m_hdllink);
+    ddsrt_mutex_lock (&e->m_mutex);
+    dds_return_t ret = really_delete_pinned_closed_locked (e, DIS_EXPLICIT);
+    assert (ret == DDS_RETCODE_OK);
+    (void) ret;
+  }
+}
+
+void dds_entity_unpin_and_drop_ref (dds_entity *e)
+{
+  if (dds_handle_unpin_and_drop_ref (&e->m_hdllink))
+  {
+    /* increment pin count unconditionally to satisfy the "pinned" requirement */
+    dds_handle_repin (&e->m_hdllink);
+    ddsrt_mutex_lock (&e->m_mutex);
+    dds_return_t ret = really_delete_pinned_closed_locked (e, DIS_EXPLICIT);
+    assert (ret == DDS_RETCODE_OK);
+    (void) ret;
+  }
+}
+
 static bool entity_has_status (const dds_entity *e)
 {
   switch (e->m_kind)
@@ -110,7 +139,7 @@ static bool entity_has_status (const dds_entity *e)
   return false;
 }
 
-dds_entity_t dds_entity_init (dds_entity *e, dds_entity *parent, dds_entity_kind_t kind, dds_qos_t *qos, const dds_listener_t *listener, status_mask_t mask)
+dds_entity_t dds_entity_init (dds_entity *e, dds_entity *parent, dds_entity_kind_t kind, bool implicit, dds_qos_t *qos, const dds_listener_t *listener, status_mask_t mask)
 {
   dds_handle_t handle;
 
@@ -125,6 +154,8 @@ dds_entity_t dds_entity_init (dds_entity *e, dds_entity *parent, dds_entity_kind
 
   /* TODO: CHAM-96: Implement dynamic enabling of entity. */
   e->m_flags |= DDS_ENTITY_ENABLED;
+  if (implicit)
+    e->m_flags |= DDS_ENTITY_IMPLICIT;
 
   /* set the status enable based on kind */
   if (entity_has_status (e))
@@ -162,12 +193,14 @@ dds_entity_t dds_entity_init (dds_entity *e, dds_entity *parent, dds_entity_kind
 
   if (kind == DDS_KIND_CYCLONEDDS)
   {
-    if ((handle = dds_handle_register_special (&e->m_hdllink, DDS_CYCLONEDDS_HANDLE)) <= 0)
+    if ((handle = dds_handle_register_special (&e->m_hdllink, implicit, true, DDS_CYCLONEDDS_HANDLE)) <= 0)
       return (dds_entity_t) handle;
   }
   else
   {
-    if ((handle = dds_handle_create (&e->m_hdllink)) <= 0)
+    /* for topics, refc counts readers/writers, for all others, it counts children (this we can get away with
+       as long as topics can't have children) */
+    if ((handle = dds_handle_create (&e->m_hdllink, implicit, (kind != DDS_KIND_TOPIC))) <= 0)
       return (dds_entity_t) handle;
   }
 
@@ -182,9 +215,12 @@ void dds_entity_init_complete (dds_entity *entity)
 
 void dds_entity_register_child (dds_entity *parent, dds_entity *child)
 {
+  /* parent must be tracking children in its refc, or children can't be added */
+  assert (ddsrt_atomic_ld32 (&parent->m_hdllink.cnt_flags) & HDL_FLAG_ALLOW_CHILDREN);
   assert (child->m_iid != 0);
   assert (ddsrt_avl_lookup (&dds_entity_children_td, &parent->m_children, &child->m_iid) == NULL);
   ddsrt_avl_insert (&dds_entity_children_td, &parent->m_children, child);
+  dds_entity_add_ref_locked (parent);
 }
 
 static dds_entity *next_non_topic_child (ddsrt_avl_tree_t *remaining_children)
@@ -227,13 +263,11 @@ static void print_delete (const dds_entity *e, enum delete_impl_state delstate ,
   printf ("delete(%p, delstate %s, iid %"PRIx64"): %s%s %d pin %u refc %u %s %s\n",
           (void *) e, (delstate == DIS_IMPLICIT) ? "implicit" : (delstate == DIS_EXPLICIT) ? "explicit" : "from_parent", iid,
           entity_kindstr (e->m_kind), (e->m_flags & DDS_ENTITY_IMPLICIT) ? " [implicit]" : "",
-          e->m_hdllink.hdl, cm & 0xfff, (cm >> 12) & 0xffff, (cm & 0x80000000) ? "closed" : "open",
+          e->m_hdllink.hdl, cm & 0xfff, (cm >> 12) & 0x7fff, (cm & 0x80000000) ? "closed" : "open",
           ddsrt_avl_is_empty (&e->m_children) ? "childless" : "has-children");
 }
 #endif
 
-static dds_return_t dds_delete_impl (dds_entity_t entity, enum delete_impl_state delstate);
-
 dds_return_t dds_delete (dds_entity_t entity)
 {
   return dds_delete_impl (entity, DIS_EXPLICIT);
@@ -252,53 +286,34 @@ static dds_return_t dds_delete_impl (dds_entity_t entity, enum delete_impl_state
 {
   dds_entity *e;
   dds_return_t ret;
-  if ((ret = dds_entity_pin (entity, &e)) < 0)
-    return ret;
-  else
+  if ((ret = dds_entity_pin_for_delete (entity, (delstate != DIS_IMPLICIT), &e)) == DDS_RETCODE_OK)
     return dds_delete_impl_pinned (e, delstate);
+  else if (ret == DDS_RETCODE_TRY_AGAIN) /* non-child refs exist */
+    return DDS_RETCODE_OK;
+  else
+    return ret;
 }
 
 dds_return_t dds_delete_impl_pinned (dds_entity *e, enum delete_impl_state delstate)
 {
-  dds_entity *child;
-  dds_return_t ret;
-
   /* Any number of threads pinning it, possibly in delete, or having pinned it and
      trying to acquire m_mutex */
 
   ddsrt_mutex_lock (&e->m_mutex);
 #if TRACE_DELETE
-  print_delete (e, delstate, iid);
+  print_delete (e, delstate, e->m_iid);
 #endif
 
   /* If another thread was racing us in delete, it will have set the CLOSING flag
      while holding m_mutex and we had better bail out. */
-  if (dds_handle_is_closed (&e->m_hdllink))
-  {
-    dds_entity_unlock (e);
-    return DDS_RETCODE_OK;
-  }
+  assert (dds_handle_is_closed (&e->m_hdllink));
+  return really_delete_pinned_closed_locked (e, delstate);
+}
 
-  /* Ignore children calling up to delete an implicit parent if there are still
-     (or again) children */
-  if (delstate == DIS_IMPLICIT)
-  {
-    if (!((e->m_flags & DDS_ENTITY_IMPLICIT) && ddsrt_avl_is_empty (&e->m_children)))
-    {
-      dds_entity_unlock (e);
-      return DDS_RETCODE_OK;
-    }
-  }
-
-  /* Drop reference, atomically setting CLOSING if no other references remain.
-     FIXME: that's not quite right: this is really only for topics.  After a call
-     to delete, the handle ought to become invalid even if the topic stays (and
-     should perhaps even be revivable via find_topic). */
-  if (! dds_handle_drop_ref (&e->m_hdllink))
-  {
-    dds_entity_unlock (e);
-    return DDS_RETCODE_OK;
-  }
+static dds_return_t really_delete_pinned_closed_locked (struct dds_entity *e, enum delete_impl_state delstate)
+{
+  dds_entity *child;
+  dds_return_t ret;
 
   /* No threads pinning it anymore, no need to worry about other threads deleting
      it, but there can still be plenty of threads that have it pinned and are
@@ -360,15 +375,23 @@ dds_return_t dds_delete_impl_pinned (dds_entity *e, enum delete_impl_state delst
     /* FIXME: dds_delete can fail if the child is being deleted in parallel, in which case: wait */
     dds_entity_t child_handle = child->m_hdllink.hdl;
     ddsrt_mutex_unlock (&e->m_mutex);
-    (void) dds_delete_impl (child_handle, DIS_FROM_PARENT);
+    ret = dds_delete_impl (child_handle, DIS_FROM_PARENT);
+    assert (ret == DDS_RETCODE_OK || ret == DDS_RETCODE_BAD_PARAMETER);
+    (void) ret;
     ddsrt_mutex_lock (&e->m_mutex);
+    if (ret == DDS_RETCODE_BAD_PARAMETER && child == next_non_topic_child (&e->m_children))
+    {
+      ddsrt_cond_wait (&e->m_cond, &e->m_mutex);
+    }
   }
   while ((child = ddsrt_avl_find_min (&dds_entity_children_td, &e->m_children)) != NULL)
   {
     assert (dds_entity_kind (child) == DDS_KIND_TOPIC);
     dds_entity_t child_handle = child->m_hdllink.hdl;
     ddsrt_mutex_unlock (&e->m_mutex);
-    (void) dds_delete_impl (child_handle, DIS_FROM_PARENT);
+    ret = dds_delete_impl (child_handle, DIS_FROM_PARENT);
+    assert (ret == DDS_RETCODE_OK);
+    (void) ret;
     ddsrt_mutex_lock (&e->m_mutex);
   }
   ddsrt_mutex_unlock (&e->m_mutex);
@@ -391,15 +414,15 @@ dds_return_t dds_delete_impl_pinned (dds_entity *e, enum delete_impl_state delst
     ddsrt_mutex_lock (&p->m_mutex);
     assert (ddsrt_avl_lookup (&dds_entity_children_td, &p->m_children, &e->m_iid) != NULL);
     ddsrt_avl_delete (&dds_entity_children_td, &p->m_children, e);
+    if (dds_handle_drop_childref_and_pin (&p->m_hdllink, delstate != DIS_FROM_PARENT))
+    {
+      assert (dds_handle_is_closed (&p->m_hdllink));
+      assert (dds_handle_is_not_refd (&p->m_hdllink));
+      assert (ddsrt_avl_is_empty (&p->m_children));
+      parent_to_delete = p;
+    }
     /* trigger parent in case it is waiting in delete */
     ddsrt_cond_broadcast (&p->m_cond);
-
-    if (delstate != DIS_FROM_PARENT && (p->m_flags & DDS_ENTITY_IMPLICIT) && ddsrt_avl_is_empty (&p->m_children))
-    {
-      if ((ret = dds_entity_pin (p->m_hdllink.hdl, &parent_to_delete)) < 0)
-        parent_to_delete = NULL;
-    }
-
     ddsrt_mutex_unlock (&p->m_mutex);
   }
 
@@ -1121,6 +1144,19 @@ dds_return_t dds_entity_pin (dds_entity_t hdl, dds_entity **eptr)
   }
 }
 
+dds_return_t dds_entity_pin_for_delete (dds_entity_t hdl, bool explicit, dds_entity **eptr)
+{
+  dds_return_t hres;
+  struct dds_handle_link *hdllink;
+  if ((hres = dds_handle_pin_for_delete (hdl, explicit, &hdllink)) < 0)
+    return hres;
+  else
+  {
+    *eptr = dds_entity_from_handle_link (hdllink);
+    return DDS_RETCODE_OK;
+  }
+}
+
 void dds_entity_unpin (dds_entity *e)
 {
   dds_handle_unpin (&e->m_hdllink);
diff --git a/src/core/ddsc/src/dds_guardcond.c b/src/core/ddsc/src/dds_guardcond.c
index 0549d52..b78dd1a 100644
--- a/src/core/ddsc/src/dds_guardcond.c
+++ b/src/core/ddsc/src/dds_guardcond.c
@@ -57,18 +57,18 @@ dds_entity_t dds_create_guardcondition (dds_entity_t owner)
   }
 
   dds_guardcond *gcond = dds_alloc (sizeof (*gcond));
-  dds_entity_t hdl = dds_entity_init (&gcond->m_entity, e, DDS_KIND_COND_GUARD, NULL, NULL, 0);
+  dds_entity_t hdl = dds_entity_init (&gcond->m_entity, e, DDS_KIND_COND_GUARD, false, NULL, NULL, 0);
   gcond->m_entity.m_iid = ddsi_iid_gen ();
   dds_entity_register_child (e, &gcond->m_entity);
   dds_entity_init_complete (&gcond->m_entity);
   dds_entity_unlock (e);
-  dds_delete_impl_pinned (&dds_global.m_entity, DIS_EXPLICIT);
+  dds_entity_unpin_and_drop_ref (&dds_global.m_entity);
   return hdl;
 
  err_entity_kind:
   dds_entity_unlock (e);
  err_entity_lock:
-  dds_delete_impl_pinned (&dds_global.m_entity, DIS_EXPLICIT);
+  dds_entity_unpin_and_drop_ref (&dds_global.m_entity);
   return rc;
 }
 
diff --git a/src/core/ddsc/src/dds_handles.c b/src/core/ddsc/src/dds_handles.c
index c4f1f6c..4e22e4e 100644
--- a/src/core/ddsc/src/dds_handles.c
+++ b/src/core/ddsc/src/dds_handles.c
@@ -20,11 +20,36 @@
 #include "dds__handles.h"
 #include "dds__types.h"
 
-#define HDL_REFCOUNT_MASK  (0x0ffff000u)
+#define HDL_REFCOUNT_MASK  (0x07fff000u)
 #define HDL_REFCOUNT_UNIT  (0x00001000u)
 #define HDL_REFCOUNT_SHIFT 12
 #define HDL_PINCOUNT_MASK  (0x00000fffu)
 
+/*
+"regular" entities other than topics:
+  - create makes it
+  - delete deletes it and its children immediately
+  - explicit domain: additional protection for bootstrapping complications need extra care
+
+implicit entities other than topics (pub, sub, domain, cyclonedds):
+  - created "spontaneously" as a consequence of creating the writer/reader/participant
+  - delete of last child causes it to disappear
+  - explicit delete treated like a delete of a "regular" entity
+  - domain, cyclonedds: bootstrapping complications require additional protection
+
+topics:
+  - create makes it
+  - never has children (so the handle's cnt_flags can have a different meaning)
+  - readers, writers keep it in existence
+  - delete deferred until no readers/writers exist
+  - an attempt at deleting it fails if in "deferred delete" state (or should it simply
+    return ok while doing nothing?), other operations keep going so, e.g., listeners
+    remain useful
+
+built-in topics:
+  - implicit variant of a topic
+*/
+
 /* Maximum number of handles is INT32_MAX - 1, but as the allocator relies on a
    random generator for finding a free one, the time spent in the dds_handle_create
    increases with an increasing number of handles.  16M handles seems likely to be
@@ -82,7 +107,7 @@ void dds_handle_server_fini (void)
                  cf & HDL_PINCOUNT_MASK, (cf & HDL_REFCOUNT_MASK) >> HDL_REFCOUNT_SHIFT,
                  cf & HDL_FLAG_PENDING ? " pending" : "",
                  cf & HDL_FLAG_CLOSING ? " closing" : "",
-                 cf & HDL_FLAG_CLOSED ? " closed" : "");
+                 cf & HDL_FLAG_DELETE_DEFERRED ? " delete-deferred" : "");
     }
     assert (ddsrt_hh_iter_first (handles.ht, &it) == NULL);
 #endif
@@ -94,9 +119,9 @@ void dds_handle_server_fini (void)
 }
 
 static bool hhadd (struct ddsrt_hh *ht, void *elem) { return ddsrt_hh_add (ht, elem); }
-static dds_handle_t dds_handle_create_int (struct dds_handle_link *link)
+static dds_handle_t dds_handle_create_int (struct dds_handle_link *link, bool implicit, bool refc_counts_children)
 {
-  ddsrt_atomic_st32 (&link->cnt_flags, HDL_FLAG_PENDING | HDL_REFCOUNT_UNIT | 1u);
+  ddsrt_atomic_st32 (&link->cnt_flags, HDL_FLAG_PENDING | (implicit ? HDL_FLAG_IMPLICIT : HDL_REFCOUNT_UNIT) | (refc_counts_children ? HDL_FLAG_ALLOW_CHILDREN : 0) | 1u);
   do {
     do {
       link->hdl = (int32_t) (ddsrt_random () & INT32_MAX);
@@ -105,7 +130,7 @@ static dds_handle_t dds_handle_create_int (struct dds_handle_link *link)
   return link->hdl;
 }
 
-dds_handle_t dds_handle_create (struct dds_handle_link *link)
+dds_handle_t dds_handle_create (struct dds_handle_link *link, bool implicit, bool allow_children)
 {
   dds_handle_t ret;
   ddsrt_mutex_lock (&handles.lock);
@@ -117,14 +142,14 @@ dds_handle_t dds_handle_create (struct dds_handle_link *link)
   else
   {
     handles.count++;
-    ret = dds_handle_create_int (link);
+    ret = dds_handle_create_int (link, implicit, allow_children);
     ddsrt_mutex_unlock (&handles.lock);
     assert (ret > 0);
   }
   return ret;
 }
 
-dds_return_t dds_handle_register_special (struct dds_handle_link *link, dds_handle_t handle)
+dds_return_t dds_handle_register_special (struct dds_handle_link *link, bool implicit, bool allow_children, dds_handle_t handle)
 {
   dds_return_t ret;
   if (handle <= 0)
@@ -138,7 +163,7 @@ dds_return_t dds_handle_register_special (struct dds_handle_link *link, dds_hand
   else
   {
     handles.count++;
-    ddsrt_atomic_st32 (&link->cnt_flags, HDL_FLAG_PENDING | HDL_REFCOUNT_UNIT | 1u);
+    ddsrt_atomic_st32 (&link->cnt_flags, HDL_FLAG_PENDING | (implicit ? HDL_FLAG_IMPLICIT : HDL_REFCOUNT_UNIT) | (allow_children ? HDL_FLAG_ALLOW_CHILDREN : 0) | 1u);
     link->hdl = handle;
     if (hhadd (handles.ht, link))
       ret = handle;
@@ -155,9 +180,9 @@ void dds_handle_unpend (struct dds_handle_link *link)
 #ifndef NDEBUG
   uint32_t cf = ddsrt_atomic_ld32 (&link->cnt_flags);
   assert ((cf & HDL_FLAG_PENDING));
-  assert (!(cf & HDL_FLAG_CLOSED));
+  assert (!(cf & HDL_FLAG_DELETE_DEFERRED));
   assert (!(cf & HDL_FLAG_CLOSING));
-  assert ((cf & HDL_REFCOUNT_MASK) >= HDL_REFCOUNT_UNIT);
+  assert ((cf & HDL_REFCOUNT_MASK) >= HDL_REFCOUNT_UNIT || (cf & HDL_FLAG_IMPLICIT));
   assert ((cf & HDL_PINCOUNT_MASK) >= 1u);
 #endif
   ddsrt_atomic_and32 (&link->cnt_flags, ~HDL_FLAG_PENDING);
@@ -171,7 +196,6 @@ int32_t dds_handle_delete (struct dds_handle_link *link)
   if (!(cf & HDL_FLAG_PENDING))
   {
     assert (cf & HDL_FLAG_CLOSING);
-    assert (cf & HDL_FLAG_CLOSED);
     assert ((cf & HDL_REFCOUNT_MASK) == 0u);
   }
   assert ((cf & HDL_PINCOUNT_MASK) == 1u);
@@ -213,7 +237,7 @@ static int32_t dds_handle_pin_int (dds_handle_t hdl, uint32_t delta, struct dds_
     rc = DDS_RETCODE_OK;
     do {
       cf = ddsrt_atomic_ld32 (&(*link)->cnt_flags);
-      if (cf & (HDL_FLAG_CLOSED | HDL_FLAG_CLOSING | HDL_FLAG_PENDING))
+      if (cf & (HDL_FLAG_CLOSING | HDL_FLAG_PENDING))
       {
         rc = DDS_RETCODE_BAD_PARAMETER;
         break;
@@ -229,6 +253,149 @@ int32_t dds_handle_pin (dds_handle_t hdl, struct dds_handle_link **link)
   return dds_handle_pin_int (hdl, 1u, link);
 }
 
+int32_t dds_handle_pin_for_delete (dds_handle_t hdl, bool explicit, struct dds_handle_link **link)
+{
+  struct dds_handle_link dummy = { .hdl = hdl };
+  int32_t rc;
+  /* it makes sense to check here for initialization: the first thing any operation
+     (other than create_participant) does is to call dds_handle_pin on the supplied
+     entity, so checking here whether the library has been initialised helps avoid
+     crashes if someone forgets to create a participant (or allows a program to
+     continue after failing to create one).
+
+     One could check that the handle is > 0, but that would catch fewer errors
+     without any advantages. */
+  if (handles.ht == NULL)
+    return DDS_RETCODE_PRECONDITION_NOT_MET;
+
+  ddsrt_mutex_lock (&handles.lock);
+  *link = ddsrt_hh_lookup (handles.ht, &dummy);
+  if (*link == NULL)
+    rc = DDS_RETCODE_BAD_PARAMETER;
+  else
+  {
+    uint32_t cf, cf1;
+    /* Assume success; bail out if the object turns out to be in the process of
+       being deleted */
+    rc = DDS_RETCODE_OK;
+    do {
+      cf = ddsrt_atomic_ld32 (&(*link)->cnt_flags);
+
+      if (cf & (HDL_FLAG_CLOSING | HDL_FLAG_PENDING))
+      {
+        /* Only one can succeed (and if closing is already set, the handle's reference has
+           already been dropped) */
+        rc = DDS_RETCODE_BAD_PARAMETER;
+        break;
+      }
+      else if (cf & HDL_FLAG_DELETE_DEFERRED)
+      {
+        /* Someone already called delete, but the operation was deferred becauses there are still
+           outstanding references.  This implies that there are no children, because then the
+           entire hierarchy would simply have been deleted.  */
+        assert (!(cf & HDL_FLAG_ALLOW_CHILDREN));
+        rc = DDS_RETCODE_ALREADY_DELETED;
+        break;
+      }
+      else if (explicit)
+      {
+        /* Explicit call to dds_delete (either by application or by parent deleting its children) */
+        if (cf & HDL_FLAG_IMPLICIT)
+        {
+          /* Entity is implicit, so handle doesn't hold a reference */
+          cf1 = (cf + 1u) | HDL_FLAG_CLOSING;
+        }
+        else if (cf & HDL_FLAG_ALLOW_CHILDREN)
+        {
+          /* Entity is explicit, so handle held a reference, refc only counts children as so is not our concern */
+          assert ((cf & HDL_REFCOUNT_MASK) > 0);
+          cf1 = (cf - HDL_REFCOUNT_UNIT + 1u) | HDL_FLAG_CLOSING;
+        }
+        else
+        {
+          /* Entity is explicit, so handle held a reference, refc counts non-children, refc > 1 means drop ref and error (so don't pin) */
+          assert ((cf & HDL_REFCOUNT_MASK) > 0);
+          if ((cf & HDL_REFCOUNT_MASK) == HDL_REFCOUNT_UNIT)
+            cf1 = (cf - HDL_REFCOUNT_UNIT + 1u) | HDL_FLAG_CLOSING;
+          else
+          {
+            cf1 = (cf - HDL_REFCOUNT_UNIT) | HDL_FLAG_DELETE_DEFERRED;
+          }
+        }
+      }
+      else
+      {
+        /* Implicit call to dds_delete (child invoking delete on its parent) */
+        if (cf & HDL_FLAG_IMPLICIT)
+        {
+          if ((cf & HDL_REFCOUNT_MASK) == HDL_REFCOUNT_UNIT)
+            cf1 = (cf - HDL_REFCOUNT_UNIT + 1u) | HDL_FLAG_CLOSING;
+          else
+          {
+            assert ((cf & HDL_REFCOUNT_MASK) > 0);
+            cf1 = (cf - HDL_REFCOUNT_UNIT);
+          }
+        }
+        else
+        {
+          /* Child can't delete an explicit parent */
+          rc = DDS_RETCODE_ILLEGAL_OPERATION;
+          break;
+        }
+      }
+
+      rc = ((cf1 & HDL_REFCOUNT_MASK) == 0 || (cf1 & HDL_FLAG_ALLOW_CHILDREN)) ? DDS_RETCODE_OK : DDS_RETCODE_TRY_AGAIN;
+    } while (!ddsrt_atomic_cas32 (&(*link)->cnt_flags, cf, cf1));
+  }
+  ddsrt_mutex_unlock (&handles.lock);
+  return rc;
+}
+
+bool dds_handle_drop_childref_and_pin (struct dds_handle_link *link, bool may_delete_parent)
+{
+  bool del_parent = false;
+  ddsrt_mutex_lock (&handles.lock);
+  uint32_t cf, cf1;
+  do {
+    cf = ddsrt_atomic_ld32 (&link->cnt_flags);
+
+    if (cf & (HDL_FLAG_CLOSING | HDL_FLAG_PENDING))
+    {
+      /* Only one can succeed; child ref still to be removed */
+      assert ((cf & HDL_REFCOUNT_MASK) > 0);
+      cf1 = (cf - HDL_REFCOUNT_UNIT);
+      del_parent = false;
+    }
+    else
+    {
+      if (cf & HDL_FLAG_IMPLICIT)
+      {
+        /* Implicit parent: delete if last ref */
+        if ((cf & HDL_REFCOUNT_MASK) == HDL_REFCOUNT_UNIT && may_delete_parent)
+        {
+          cf1 = (cf - HDL_REFCOUNT_UNIT + 1u) | HDL_FLAG_CLOSING;
+          del_parent = true;
+        }
+        else
+        {
+          assert ((cf & HDL_REFCOUNT_MASK) > 0);
+          cf1 = (cf - HDL_REFCOUNT_UNIT);
+          del_parent = false;
+        }
+      }
+      else
+      {
+        /* Child can't delete an explicit parent; child ref still to be removed */
+        assert ((cf & HDL_REFCOUNT_MASK) > 0);
+        cf1 = (cf - HDL_REFCOUNT_UNIT);
+        del_parent = false;
+      }
+    }
+  } while (!ddsrt_atomic_cas32 (&link->cnt_flags, cf, cf1));
+  ddsrt_mutex_unlock (&handles.lock);
+  return del_parent;
+}
+
 int32_t dds_handle_pin_and_ref (dds_handle_t hdl, struct dds_handle_link **link)
 {
   return dds_handle_pin_int (hdl, HDL_REFCOUNT_UNIT + 1u, link);
@@ -237,7 +404,6 @@ int32_t dds_handle_pin_and_ref (dds_handle_t hdl, struct dds_handle_link **link)
 void dds_handle_repin (struct dds_handle_link *link)
 {
   uint32_t x = ddsrt_atomic_inc32_nv (&link->cnt_flags);
-  assert (!(x & HDL_FLAG_CLOSED));
   (void) x;
 }
 
@@ -245,7 +411,6 @@ void dds_handle_unpin (struct dds_handle_link *link)
 {
 #ifndef NDEBUG
   uint32_t cf = ddsrt_atomic_ld32 (&link->cnt_flags);
-  assert (!(cf & HDL_FLAG_CLOSED));
   if (cf & HDL_FLAG_CLOSING)
     assert ((cf & HDL_PINCOUNT_MASK) > 1u);
   else
@@ -266,16 +431,47 @@ void dds_handle_add_ref (struct dds_handle_link *link)
 
 bool dds_handle_drop_ref (struct dds_handle_link *link)
 {
-  assert ((ddsrt_atomic_ld32 (&link->cnt_flags) & HDL_REFCOUNT_MASK) != 0);
   uint32_t old, new;
   do {
     old = ddsrt_atomic_ld32 (&link->cnt_flags);
-    if ((old & HDL_REFCOUNT_MASK) != HDL_REFCOUNT_UNIT)
-      new = old - HDL_REFCOUNT_UNIT;
-    else
-      new = (old - HDL_REFCOUNT_UNIT) | HDL_FLAG_CLOSING;
+    assert ((old & HDL_REFCOUNT_MASK) > 0);
+    new = old - HDL_REFCOUNT_UNIT;
+    if ((old & HDL_REFCOUNT_MASK) == HDL_REFCOUNT_UNIT)
+      new |= HDL_FLAG_CLOSING;
   } while (!ddsrt_atomic_cas32 (&link->cnt_flags, old, new));
-  return (new & HDL_REFCOUNT_MASK) == 0;
+  ddsrt_mutex_lock (&handles.lock);
+  if ((new & (HDL_FLAG_CLOSING | HDL_PINCOUNT_MASK)) == (HDL_FLAG_CLOSING | 1u))
+  {
+    ddsrt_cond_broadcast (&handles.cond);
+  }
+  ddsrt_mutex_unlock (&handles.lock);
+  return (new & (HDL_FLAG_CLOSING | HDL_REFCOUNT_MASK)) == (HDL_FLAG_CLOSING | 0);
+}
+
+bool dds_handle_unpin_and_drop_ref (struct dds_handle_link *link)
+{
+  uint32_t old, new;
+  do {
+    old = ddsrt_atomic_ld32 (&link->cnt_flags);
+    assert ((old & HDL_REFCOUNT_MASK) > 0);
+    assert ((old & HDL_PINCOUNT_MASK) > 0);
+    new = old - HDL_REFCOUNT_UNIT - 1u;
+    if ((old & HDL_REFCOUNT_MASK) == HDL_REFCOUNT_UNIT && (old & HDL_FLAG_IMPLICIT))
+      new |= HDL_FLAG_CLOSING;
+  } while (!ddsrt_atomic_cas32 (&link->cnt_flags, old, new));
+  ddsrt_mutex_lock (&handles.lock);
+  if ((new & (HDL_FLAG_CLOSING | HDL_PINCOUNT_MASK)) == (HDL_FLAG_CLOSING | 1u))
+  {
+    ddsrt_cond_broadcast (&handles.cond);
+  }
+  ddsrt_mutex_unlock (&handles.lock);
+  return (new & (HDL_FLAG_CLOSING | HDL_REFCOUNT_MASK)) == (HDL_FLAG_CLOSING | 0);
+}
+
+bool dds_handle_close (struct dds_handle_link *link)
+{
+  uint32_t old = ddsrt_atomic_or32_ov (&link->cnt_flags, HDL_FLAG_CLOSING);
+  return (old & HDL_REFCOUNT_MASK) == 0;
 }
 
 void dds_handle_close_wait (struct dds_handle_link *link)
@@ -283,17 +479,18 @@ void dds_handle_close_wait (struct dds_handle_link *link)
 #ifndef NDEBUG
   uint32_t cf = ddsrt_atomic_ld32 (&link->cnt_flags);
   assert ((cf & HDL_FLAG_CLOSING));
-  assert (!(cf & HDL_FLAG_CLOSED));
-  assert ((cf & HDL_REFCOUNT_MASK) == 0u);
   assert ((cf & HDL_PINCOUNT_MASK) >= 1u);
 #endif
   ddsrt_mutex_lock (&handles.lock);
   while ((ddsrt_atomic_ld32 (&link->cnt_flags) & HDL_PINCOUNT_MASK) != 1u)
     ddsrt_cond_wait (&handles.cond, &handles.lock);
   /* only one thread may call close_wait on a given handle */
-  assert (!(ddsrt_atomic_ld32 (&link->cnt_flags) & HDL_FLAG_CLOSED));
-  ddsrt_atomic_or32 (&link->cnt_flags, HDL_FLAG_CLOSED);
   ddsrt_mutex_unlock (&handles.lock);
 }
 
+bool dds_handle_is_not_refd (struct dds_handle_link *link)
+{
+  return ((ddsrt_atomic_ld32 (&link->cnt_flags) & HDL_REFCOUNT_MASK) == 0);
+}
+
 extern inline bool dds_handle_is_closed (struct dds_handle_link *link);
diff --git a/src/core/ddsc/src/dds_init.c b/src/core/ddsc/src/dds_init.c
index 9ad0299..7444a26 100644
--- a/src/core/ddsc/src/dds_init.c
+++ b/src/core/ddsc/src/dds_init.c
@@ -119,9 +119,8 @@ dds_return_t dds_init (void)
     goto fail_handleserver;
   }
 
-  dds_entity_init (&dds_global.m_entity, NULL, DDS_KIND_CYCLONEDDS, NULL, NULL, 0);
+  dds_entity_init (&dds_global.m_entity, NULL, DDS_KIND_CYCLONEDDS, true, NULL, NULL, 0);
   dds_global.m_entity.m_iid = ddsi_iid_gen ();
-  dds_global.m_entity.m_flags = DDS_ENTITY_IMPLICIT;
   dds_handle_repin (&dds_global.m_entity.m_hdllink);
   dds_entity_add_ref_locked (&dds_global.m_entity);
   dds_entity_init_complete (&dds_global.m_entity);
diff --git a/src/core/ddsc/src/dds_participant.c b/src/core/ddsc/src/dds_participant.c
index 4825f23..cafa6f9 100644
--- a/src/core/ddsc/src/dds_participant.c
+++ b/src/core/ddsc/src/dds_participant.c
@@ -117,7 +117,7 @@ dds_entity_t dds_create_participant (const dds_domainid_t domain, const dds_qos_
   }
 
   pp = dds_alloc (sizeof (*pp));
-  if ((ret = dds_entity_init (&pp->m_entity, &dom->m_entity, DDS_KIND_PARTICIPANT, new_qos, listener, DDS_PARTICIPANT_STATUS_MASK)) < 0)
+  if ((ret = dds_entity_init (&pp->m_entity, &dom->m_entity, DDS_KIND_PARTICIPANT, false, new_qos, listener, DDS_PARTICIPANT_STATUS_MASK)) < 0)
     goto err_entity_init;
 
   pp->m_entity.m_guid = guid;
@@ -132,8 +132,8 @@ dds_entity_t dds_create_participant (const dds_domainid_t domain, const dds_qos_
 
   dds_entity_init_complete (&pp->m_entity);
   /* drop temporary extra ref to domain, dds_init */
-  dds_delete (dom->m_entity.m_hdllink.hdl);
-  dds_delete_impl_pinned (&dds_global.m_entity, DIS_EXPLICIT);
+  dds_entity_unpin_and_drop_ref (&dom->m_entity);
+  dds_entity_unpin_and_drop_ref (&dds_global.m_entity);
   return ret;
 
 err_entity_init:
@@ -141,9 +141,9 @@ err_entity_init:
 err_new_participant:
 err_qos_validation:
   dds_delete_qos (new_qos);
-  dds_delete (dom->m_entity.m_hdllink.hdl);
+  dds_entity_unpin_and_drop_ref (&dom->m_entity);
 err_domain_create:
-  dds_delete_impl_pinned (&dds_global.m_entity, DIS_EXPLICIT);
+  dds_entity_unpin_and_drop_ref (&dds_global.m_entity);
 err_dds_init:
   return ret;
 }
@@ -175,6 +175,6 @@ dds_return_t dds_lookup_participant (dds_domainid_t domain_id, dds_entity_t *par
     }
   }
   ddsrt_mutex_unlock (&dds_global.m_mutex);
-  dds_delete_impl_pinned (&dds_global.m_entity, DIS_EXPLICIT);
+  dds_entity_unpin_and_drop_ref (&dds_global.m_entity);
   return ret;
 }
diff --git a/src/core/ddsc/src/dds_publisher.c b/src/core/ddsc/src/dds_publisher.c
index dc059af..ae20658 100644
--- a/src/core/ddsc/src/dds_publisher.c
+++ b/src/core/ddsc/src/dds_publisher.c
@@ -45,17 +45,13 @@ const struct dds_entity_deriver dds_entity_deriver_publisher = {
   .validate_status = dds_publisher_status_validate
 };
 
-dds_entity_t dds_create_publisher (dds_entity_t participant, const dds_qos_t *qos, const dds_listener_t *listener)
+dds_entity_t dds__create_publisher_l (dds_participant *par, bool implicit, const dds_qos_t *qos, const dds_listener_t *listener)
 {
-  dds_participant *par;
   dds_publisher *pub;
   dds_entity_t hdl;
   dds_qos_t *new_qos;
   dds_return_t ret;
 
-  if ((ret = dds_participant_lock (participant, &par)) != DDS_RETCODE_OK)
-    return ret;
-
   new_qos = dds_create_qos ();
   if (qos)
     nn_xqos_mergein_missing (new_qos, qos, DDS_PUBLISHER_QOS_MASK);
@@ -67,10 +63,21 @@ dds_entity_t dds_create_publisher (dds_entity_t participant, const dds_qos_t *qo
   }
 
   pub = dds_alloc (sizeof (*pub));
-  hdl = dds_entity_init (&pub->m_entity, &par->m_entity, DDS_KIND_PUBLISHER, new_qos, listener, DDS_PUBLISHER_STATUS_MASK);
+  hdl = dds_entity_init (&pub->m_entity, &par->m_entity, DDS_KIND_PUBLISHER, implicit, new_qos, listener, DDS_PUBLISHER_STATUS_MASK);
   pub->m_entity.m_iid = ddsi_iid_gen ();
   dds_entity_register_child (&par->m_entity, &pub->m_entity);
   dds_entity_init_complete (&pub->m_entity);
+  return hdl;
+}
+
+dds_entity_t dds_create_publisher (dds_entity_t participant, const dds_qos_t *qos, const dds_listener_t *listener)
+{
+  dds_participant *par;
+  dds_entity_t hdl;
+  dds_return_t ret;
+  if ((ret = dds_participant_lock (participant, &par)) != DDS_RETCODE_OK)
+    return ret;
+  hdl = dds__create_publisher_l (par, false, qos, listener);
   dds_participant_unlock (par);
   return hdl;
 }
diff --git a/src/core/ddsc/src/dds_readcond.c b/src/core/ddsc/src/dds_readcond.c
index 806f913..8028a1d 100644
--- a/src/core/ddsc/src/dds_readcond.c
+++ b/src/core/ddsc/src/dds_readcond.c
@@ -41,7 +41,7 @@ dds_readcond *dds_create_readcond (dds_reader *rd, dds_entity_kind_t kind, uint3
 {
   dds_readcond *cond = dds_alloc (sizeof (*cond));
   assert ((kind == DDS_KIND_COND_READ && filter == 0) || (kind == DDS_KIND_COND_QUERY && filter != 0));
-  (void) dds_entity_init (&cond->m_entity, &rd->m_entity, kind, NULL, NULL, 0);
+  (void) dds_entity_init (&cond->m_entity, &rd->m_entity, kind, false, NULL, NULL, 0);
   cond->m_entity.m_iid = ddsi_iid_gen ();
   dds_entity_register_child (&rd->m_entity, &cond->m_entity);
   cond->m_sample_states = mask & DDS_ANY_SAMPLE_STATE;
diff --git a/src/core/ddsc/src/dds_reader.c b/src/core/ddsc/src/dds_reader.c
index 4fcf222..22e118b 100644
--- a/src/core/ddsc/src/dds_reader.c
+++ b/src/core/ddsc/src/dds_reader.c
@@ -62,11 +62,11 @@ static dds_return_t dds_reader_delete (dds_entity *e) ddsrt_nonnull_all;
 static dds_return_t dds_reader_delete (dds_entity *e)
 {
   dds_reader * const rd = (dds_reader *) e;
-  (void) dds_delete (rd->m_topic->m_entity.m_hdllink.hdl);
   dds_free (rd->m_loan);
   thread_state_awake (lookup_thread_state (), &e->m_domain->gv);
   dds_rhc_free (rd->m_rhc);
   thread_state_asleep (lookup_thread_state ());
+  dds_entity_drop_ref (&rd->m_topic->m_entity);
   return DDS_RETCODE_OK;
 }
 
@@ -332,36 +332,37 @@ static dds_entity_t dds_create_reader_int (dds_entity_t participant_or_subscribe
     case DDS_BUILTIN_TOPIC_DCPSSUBSCRIPTION:
       internal_topic = true;
       subscriber = dds__get_builtin_subscriber (participant_or_subscriber);
+      if ((ret = dds_subscriber_lock (subscriber, &sub)) != DDS_RETCODE_OK)
+        return ret;
       t = dds__get_builtin_topic (subscriber, topic);
       break;
 
     default: {
       dds_entity *p_or_s;
-      if ((ret = dds_entity_pin (participant_or_subscriber, &p_or_s)) != DDS_RETCODE_OK)
+      if ((ret = dds_entity_lock (participant_or_subscriber, DDS_KIND_DONTCARE, &p_or_s)) != DDS_RETCODE_OK)
         return ret;
-      if (dds_entity_kind (p_or_s) == DDS_KIND_PARTICIPANT)
-        subscriber = dds_create_subscriber (participant_or_subscriber, qos, NULL);
-      else
-        subscriber = participant_or_subscriber;
-      dds_entity_unpin (p_or_s);
+      switch (dds_entity_kind (p_or_s))
+      {
+        case DDS_KIND_SUBSCRIBER:
+          subscriber = participant_or_subscriber;
+          sub = (dds_subscriber *) p_or_s;
+          break;
+        case DDS_KIND_PARTICIPANT:
+          subscriber = dds__create_subscriber_l ((dds_participant *) p_or_s, true, qos, NULL);
+          dds_entity_unlock (p_or_s);
+          if ((ret = dds_subscriber_lock (subscriber, &sub)) < 0)
+            return ret;
+          break;
+        default:
+          dds_entity_unlock (p_or_s);
+          return DDS_RETCODE_ILLEGAL_OPERATION;
+      }
       internal_topic = false;
       t = topic;
       break;
     }
   }
 
-  if ((ret = dds_subscriber_lock (subscriber, &sub)) != DDS_RETCODE_OK)
-  {
-    reader = ret;
-    goto err_sub_lock;
-  }
-
-  if (subscriber != participant_or_subscriber && !internal_topic)
-  {
-    /* Delete implicit subscriber if reader creation fails */
-    sub->m_entity.m_flags |= DDS_ENTITY_IMPLICIT;
-  }
-
   if ((ret = dds_topic_lock (t, &tp)) != DDS_RETCODE_OK)
   {
     reader = ret;
@@ -405,7 +406,7 @@ static dds_entity_t dds_create_reader_int (dds_entity_t participant_or_subscribe
 
   /* Create reader and associated read cache (if not provided by caller) */
   rd = dds_alloc (sizeof (*rd));
-  reader = dds_entity_init (&rd->m_entity, &sub->m_entity, DDS_KIND_READER, rqos, listener, DDS_READER_STATUS_MASK);
+  reader = dds_entity_init (&rd->m_entity, &sub->m_entity, DDS_KIND_READER, false, rqos, listener, DDS_READER_STATUS_MASK);
   rd->m_sample_rejected_status.last_reason = DDS_NOT_REJECTED;
   rd->m_topic = tp;
   rd->m_rhc = rhc ? rhc : dds_rhc_default_new (rd, tp->m_stopic);
@@ -431,12 +432,6 @@ static dds_entity_t dds_create_reader_int (dds_entity_t participant_or_subscribe
 
   dds_topic_unlock (tp);
   dds_subscriber_unlock (sub);
-
-  if (internal_topic)
-  {
-    /* If topic is builtin, then the topic entity is local and should be deleted because the application won't. */
-    dds_delete (t);
-  }
   return reader;
 
 err_bad_qos:
@@ -446,9 +441,6 @@ err_tp_lock:
   dds_subscriber_unlock (sub);
   if ((sub->m_entity.m_flags & DDS_ENTITY_IMPLICIT) != 0)
     (void) dds_delete (subscriber);
-err_sub_lock:
-  if (internal_topic)
-    dds_delete (t);
   return reader;
 }
 
diff --git a/src/core/ddsc/src/dds_subscriber.c b/src/core/ddsc/src/dds_subscriber.c
index 9fe13bc..0729064 100644
--- a/src/core/ddsc/src/dds_subscriber.c
+++ b/src/core/ddsc/src/dds_subscriber.c
@@ -45,7 +45,7 @@ const struct dds_entity_deriver dds_entity_deriver_subscriber = {
   .validate_status = dds_subscriber_status_validate
 };
 
-dds_entity_t dds__create_subscriber_l (dds_participant *participant, const dds_qos_t *qos, const dds_listener_t *listener)
+dds_entity_t dds__create_subscriber_l (dds_participant *participant, bool implicit, const dds_qos_t *qos, const dds_listener_t *listener)
 {
   /* participant entity lock must be held */
   dds_subscriber *sub;
@@ -64,7 +64,7 @@ dds_entity_t dds__create_subscriber_l (dds_participant *participant, const dds_q
   }
 
   sub = dds_alloc (sizeof (*sub));
-  subscriber = dds_entity_init (&sub->m_entity, &participant->m_entity, DDS_KIND_SUBSCRIBER, new_qos, listener, DDS_SUBSCRIBER_STATUS_MASK);
+  subscriber = dds_entity_init (&sub->m_entity, &participant->m_entity, DDS_KIND_SUBSCRIBER, implicit, new_qos, listener, DDS_SUBSCRIBER_STATUS_MASK);
   sub->m_entity.m_iid = ddsi_iid_gen ();
   dds_entity_register_child (&participant->m_entity, &sub->m_entity);
   dds_entity_init_complete (&sub->m_entity);
@@ -78,7 +78,7 @@ dds_entity_t dds_create_subscriber (dds_entity_t participant, const dds_qos_t *q
   dds_return_t ret;
   if ((ret = dds_participant_lock (participant, &par)) != DDS_RETCODE_OK)
     return ret;
-  hdl = dds__create_subscriber_l (par, qos, listener);
+  hdl = dds__create_subscriber_l (par, false, qos, listener);
   dds_participant_unlock (par);
   return hdl;
 }
diff --git a/src/core/ddsc/src/dds_topic.c b/src/core/ddsc/src/dds_topic.c
index 6101b79..4630336 100644
--- a/src/core/ddsc/src/dds_topic.c
+++ b/src/core/ddsc/src/dds_topic.c
@@ -31,6 +31,7 @@
 #include "dds/ddsi/ddsi_iid.h"
 #include "dds/ddsi/q_plist.h"
 #include "dds/ddsi/q_globals.h"
+#include "dds__serdata_builtintopic.h"
 
 DECL_ENTITY_LOCK_UNLOCK (extern inline, dds_topic)
 
@@ -135,12 +136,16 @@ static bool dds_find_topic_check_and_add_ref (dds_entity_t participant, dds_enti
     ret = false;
   else
   {
-    /* FIXME: calling addref is wrong because the Cyclone library has no
-       knowledge of the reference and hence simply deleting the participant
-       won't make the ref count drop to 0.  On the other hand, the DDS spec
-       says find_topic (and a second call to create_topic) return a new
-       proxy that must separately be deleted.  */
-    dds_entity_add_ref_locked (&tp->m_entity);
+    /* Simply return the same topic, though that is different to the spirit
+       of the DDS specification, which gives you a unique copy.  Giving that
+       unique copy means there potentially many versions of exactly the same
+       topic around, and that two entities can be dealing with the same data
+       even though they have different topics objects (though with the same
+       name).  That I find a confusing model.
+
+       As far as I can tell, the only benefit is the ability to set different
+       listeners on the various copies of the topic.  And that seems to be a
+       really small benefit. */
     ret = true;
   }
   dds_topic_unlock (tp);
@@ -259,12 +264,7 @@ static dds_return_t create_topic_topic_arbitrary_check_sertopic (dds_entity_t pa
     ret = DDS_RETCODE_INCONSISTENT_POLICY;
   else
   {
-    /* FIXME: calling addref is wrong because the Cyclone library has no
-       knowledge of the reference and hence simply deleting the participant
-       won't make the ref count drop to 0.  On the other hand, the DDS spec
-       says find_topic (and a second call to create_topic) return a new
-       proxy that must separately be deleted.  */
-    dds_entity_add_ref_locked (&tp->m_entity);
+    /* See dds_find_topic_check_and_add_ref */
     ret = DDS_RETCODE_OK;
   }
   dds_topic_unlock (tp);
@@ -429,7 +429,8 @@ dds_entity_t dds_create_topic_arbitrary (dds_entity_t participant, struct ddsi_s
 
   /* Create topic */
   top = dds_alloc (sizeof (*top));
-  hdl = dds_entity_init (&top->m_entity, &par->m_entity, DDS_KIND_TOPIC, new_qos, listener, DDS_TOPIC_STATUS_MASK);
+  /* FIXME: setting "implicit" based on sertopic->ops is a hack */
+  hdl = dds_entity_init (&top->m_entity, &par->m_entity, DDS_KIND_TOPIC, (sertopic->ops == &ddsi_sertopic_ops_builtintopic), new_qos, listener, DDS_TOPIC_STATUS_MASK);
   top->m_entity.m_iid = ddsi_iid_gen ();
   dds_entity_register_child (&par->m_entity, &top->m_entity);
   top->m_stopic = sertopic;
diff --git a/src/core/ddsc/src/dds_waitset.c b/src/core/ddsc/src/dds_waitset.c
index a0ae00c..64e15d6 100644
--- a/src/core/ddsc/src/dds_waitset.c
+++ b/src/core/ddsc/src/dds_waitset.c
@@ -166,7 +166,7 @@ dds_entity_t dds_create_waitset (dds_entity_t owner)
   }
 
   dds_waitset *waitset = dds_alloc (sizeof (*waitset));
-  dds_entity_t hdl = dds_entity_init (&waitset->m_entity, e, DDS_KIND_WAITSET, NULL, NULL, 0);
+  dds_entity_t hdl = dds_entity_init (&waitset->m_entity, e, DDS_KIND_WAITSET, false, NULL, NULL, 0);
   ddsrt_mutex_init (&waitset->wait_lock);
   ddsrt_cond_init (&waitset->wait_cond);
   waitset->m_entity.m_iid = ddsi_iid_gen ();
@@ -176,13 +176,13 @@ dds_entity_t dds_create_waitset (dds_entity_t owner)
   waitset->entities = NULL;
   dds_entity_init_complete (&waitset->m_entity);
   dds_entity_unlock (e);
-  dds_delete_impl_pinned (&dds_global.m_entity, DIS_EXPLICIT);
+  dds_entity_unpin_and_drop_ref (&dds_global.m_entity);
   return hdl;
 
  err_entity_kind:
   dds_entity_unlock (e);
  err_entity_lock:
-  dds_delete_impl_pinned (&dds_global.m_entity, DIS_EXPLICIT);
+  dds_entity_unpin_and_drop_ref (&dds_global.m_entity);
   return rc;
 }
 
diff --git a/src/core/ddsc/src/dds_writer.c b/src/core/ddsc/src/dds_writer.c
index 4f829ae..f0c0bc4 100644
--- a/src/core/ddsc/src/dds_writer.c
+++ b/src/core/ddsc/src/dds_writer.c
@@ -209,13 +209,12 @@ static dds_return_t dds_writer_delete (dds_entity *e) ddsrt_nonnull_all;
 static dds_return_t dds_writer_delete (dds_entity *e)
 {
   dds_writer * const wr = (dds_writer *) e;
-  dds_return_t ret;
   /* FIXME: not freeing WHC here because it is owned by the DDSI entity */
   thread_state_awake (lookup_thread_state (), &e->m_domain->gv);
   nn_xpack_free (wr->m_xp);
   thread_state_asleep (lookup_thread_state ());
-  ret = dds_delete (wr->m_topic->m_entity.m_hdllink.hdl);
-  return ret;
+  dds_entity_drop_ref (&wr->m_topic->m_entity);
+  return DDS_RETCODE_OK;
 }
 
 static dds_return_t dds_writer_qos_set (dds_entity *e, const dds_qos_t *qos, bool enabled)
@@ -277,21 +276,27 @@ dds_entity_t dds_create_writer (dds_entity_t participant_or_publisher, dds_entit
 
   {
     dds_entity *p_or_p;
-    if ((rc = dds_entity_pin (participant_or_publisher, &p_or_p)) != DDS_RETCODE_OK)
+    if ((rc = dds_entity_lock (participant_or_publisher, DDS_KIND_DONTCARE, &p_or_p)) != DDS_RETCODE_OK)
       return rc;
-    if (dds_entity_kind (p_or_p) == DDS_KIND_PARTICIPANT)
-      publisher = dds_create_publisher (participant_or_publisher, qos, NULL);
-    else
-      publisher = participant_or_publisher;
-    dds_entity_unpin (p_or_p);
+    switch (dds_entity_kind (p_or_p))
+    {
+      case DDS_KIND_PUBLISHER:
+        publisher = participant_or_publisher;
+        pub = (dds_publisher *) p_or_p;
+        break;
+      case DDS_KIND_PARTICIPANT:
+        publisher = dds__create_publisher_l ((dds_participant *) p_or_p, true, qos, NULL);
+        dds_entity_unlock (p_or_p);
+        if ((rc = dds_publisher_lock (publisher, &pub)) < 0)
+          return rc;
+        break;
+      default:
+        dds_entity_unlock (p_or_p);
+        return DDS_RETCODE_ILLEGAL_OPERATION;
+    }
   }
 
-  if ((rc = dds_publisher_lock (publisher, &pub)) != DDS_RETCODE_OK)
-    return rc;
-
   ddsi_tran_conn_t conn = pub->m_entity.m_domain->gv.data_conn_uc;
-  if (publisher != participant_or_publisher)
-    pub->m_entity.m_flags |= DDS_ENTITY_IMPLICIT;
 
   if ((rc = dds_topic_lock (topic, &tp)) != DDS_RETCODE_OK)
     goto err_tp_lock;
@@ -322,7 +327,7 @@ dds_entity_t dds_create_writer (dds_entity_t participant_or_publisher, dds_entit
 
   /* Create writer */
   wr = dds_alloc (sizeof (*wr));
-  writer = dds_entity_init (&wr->m_entity, &pub->m_entity, DDS_KIND_WRITER, wqos, listener, DDS_WRITER_STATUS_MASK);
+  writer = dds_entity_init (&wr->m_entity, &pub->m_entity, DDS_KIND_WRITER, false, wqos, listener, DDS_WRITER_STATUS_MASK);
 
   wr->m_topic = tp;
   dds_entity_add_ref_locked (&tp->m_entity);
diff --git a/src/core/ddsc/tests/config.c b/src/core/ddsc/tests/config.c
index 3c9acb0..6f5789c 100644
--- a/src/core/ddsc/tests/config.c
+++ b/src/core/ddsc/tests/config.c
@@ -25,96 +25,88 @@
 #define URI_VARIABLE DDS_PROJECT_NAME_NOSPACE_CAPS"_URI"
 #define MAX_PARTICIPANTS_VARIABLE "MAX_PARTICIPANTS"
 
-static void config__check_env(
-    const char * env_variable,
-    const char * expected_value)
+static void config__check_env (const char *env_variable, const char *expected_value)
 {
-    char * env_uri = NULL;
-    ddsrt_getenv(env_variable, &env_uri);
-#if 0
-    const char * const env_not_set = "Environment variable '%s' isn't set. This needs to be set to '%s' for this test to run.";
-    const char * const env_not_as_expected = "Environment variable '%s' has an unexpected value: '%s' (expected: '%s')";
-#endif
-
+  char *env_uri = NULL;
+  ddsrt_getenv (env_variable, &env_uri);
 #ifdef FORCE_ENV
+  {
+    bool env_ok;
+
+    if (env_uri == NULL)
+      env_ok = false;
+    else if (strncmp (env_uri, expected_value, strlen (expected_value)) != 0)
+      env_ok = false;
+    else
+      env_ok = true;
+
+    if (!env_ok)
     {
-        bool env_ok;
-
-        if ( env_uri == NULL ) {
-            env_ok = false;
-        } else if ( strncmp(env_uri, expected_value, strlen(expected_value)) != 0 ) {
-            env_ok = false;
-        } else {
-            env_ok = true;
-        }
-
-        if ( !env_ok ) {
-            dds_return_t r;
-
-            r = ddsrt_setenv(env_variable, expected_value);
-            CU_ASSERT_EQUAL_FATAL(r, DDS_RETCODE_OK);
-        }
+      dds_return_t r = ddsrt_setenv (env_variable, expected_value);
+      CU_ASSERT_EQUAL_FATAL (r, DDS_RETCODE_OK);
     }
+  }
 #else
-    CU_ASSERT_PTR_NOT_NULL_FATAL(env_uri);
-    CU_ASSERT_STRING_EQUAL_FATAL(env_uri, expected_value);
+  CU_ASSERT_PTR_NOT_NULL_FATAL (env_uri);
+  CU_ASSERT_STRING_EQUAL_FATAL (env_uri, expected_value);
 #endif /* FORCE_ENV */
-
 }
 
-CU_Test(ddsc_config, simple_udp, .init = ddsrt_init, .fini = ddsrt_fini) {
-
-    dds_entity_t participant;
-
-    config__check_env(URI_VARIABLE, CONFIG_ENV_SIMPLE_UDP);
-    config__check_env(MAX_PARTICIPANTS_VARIABLE, CONFIG_ENV_MAX_PARTICIPANTS);
-
-    participant = dds_create_participant(DDS_DOMAIN_DEFAULT, NULL, NULL);
-
-    CU_ASSERT_FATAL(participant> 0);
-
-    dds_delete(participant);
+CU_Test (ddsc_config, simple_udp, .init = ddsrt_init, .fini = ddsrt_fini)
+{
+  dds_entity_t participant;
+  config__check_env (URI_VARIABLE, CONFIG_ENV_SIMPLE_UDP);
+  config__check_env (MAX_PARTICIPANTS_VARIABLE, CONFIG_ENV_MAX_PARTICIPANTS);
+  participant = dds_create_participant (DDS_DOMAIN_DEFAULT, NULL, NULL);
+  CU_ASSERT_FATAL (participant> 0);
+  dds_delete (participant);
 }
 
-CU_Test(ddsc_config, user_config, .init = ddsrt_init, .fini = ddsrt_fini) {
+CU_Test (ddsc_config, user_config, .init = ddsrt_init, .fini = ddsrt_fini)
+{
+  dds_entity_t domain;
+  domain = dds_create_domain (1,
+                              "<"DDS_PROJECT_NAME"><Domain><Id>any</Id></Domain>"
+                              "<DDSI2E><Internal><MaxParticipants>2</MaxParticipants></Internal></DDSI2E>"
+                              "</"DDS_PROJECT_NAME">");
+  CU_ASSERT_FATAL (domain > 0);
 
-    CU_ASSERT_FATAL(dds_create_domain(1,
-         "<"DDS_PROJECT_NAME"><Domain><Id>any</Id></Domain>"
-           "<DDSI2E><Internal><MaxParticipants>2</MaxParticipants></Internal></DDSI2E>"
-         "</"DDS_PROJECT_NAME">") == DDS_RETCODE_OK);
+  dds_entity_t participant_1 = dds_create_participant (1, NULL, NULL);
+  CU_ASSERT_FATAL(participant_1 > 0);
 
-    dds_entity_t participant_1;
-    dds_entity_t participant_2;
-    dds_entity_t participant_3;
+  dds_entity_t participant_2 = dds_create_participant (1, NULL, NULL);
+  CU_ASSERT_FATAL(participant_2 > 0);
 
-    participant_1 = dds_create_participant(1, NULL, NULL);
+  dds_entity_t participant_3 = dds_create_participant (1, NULL, NULL);
+  CU_ASSERT(participant_3 < 0);
 
-    CU_ASSERT_FATAL(participant_1 > 0);
-
-    participant_2 = dds_create_participant(1, NULL, NULL);
-
-    CU_ASSERT_FATAL(participant_2 > 0);
-
-    participant_3 = dds_create_participant(1, NULL, NULL);
-
-    CU_ASSERT(participant_3 <= 0);
-
-    dds_delete(participant_3);
-    dds_delete(participant_2);
-    dds_delete(participant_1);
+  dds_delete (domain);
 }
 
-CU_Test(ddsc_config, incorrect_config, .init = ddsrt_init, .fini = ddsrt_fini) {
+CU_Test (ddsc_config, incorrect_config, .init = ddsrt_init, .fini = ddsrt_fini)
+{
+  dds_entity_t dom;
 
-    CU_ASSERT_FATAL(dds_create_domain(1, NULL) == DDS_RETCODE_BAD_PARAMETER);
-    CU_ASSERT_FATAL(dds_create_domain(1, "<CycloneDDS incorrect XML") != DDS_RETCODE_OK);
-    CU_ASSERT_FATAL(dds_create_domain(DDS_DOMAIN_DEFAULT,
-         "<"DDS_PROJECT_NAME"><Domain><Id>any</Id></Domain>"
-           "<DDSI2E><Internal><MaxParticipants>2</MaxParticipants></Internal></DDSI2E>"
-         "</"DDS_PROJECT_NAME">") == DDS_RETCODE_BAD_PARAMETER);
-    CU_ASSERT_FATAL(dds_create_domain(2,
-         "<"DDS_PROJECT_NAME"><Domain><Id>any</Id></Domain>"
-           "<DDSI2E><Internal><MaxParticipants>2</MaxParticipants></Internal></DDSI2E>"
-         "</"DDS_PROJECT_NAME">") == DDS_RETCODE_OK);
-    CU_ASSERT_FATAL(dds_create_domain(2, "") == DDS_RETCODE_PRECONDITION_NOT_MET);
+  dom = dds_create_domain (1, NULL);
+  CU_ASSERT_FATAL (dom == DDS_RETCODE_BAD_PARAMETER);
+
+  dom = dds_create_domain (1, "<CycloneDDS incorrect XML");
+  CU_ASSERT_FATAL (dom == DDS_RETCODE_ERROR); /* FIXME: "error" is rather unspecific for a bad configuration */
+
+  dom = dds_create_domain (DDS_DOMAIN_DEFAULT,
+                           "<"DDS_PROJECT_NAME"><Domain><Id>any</Id></Domain>"
+                           "<DDSI2E><Internal><MaxParticipants>2</MaxParticipants></Internal></DDSI2E>"
+                           "</"DDS_PROJECT_NAME">");
+  CU_ASSERT_FATAL (dom == DDS_RETCODE_BAD_PARAMETER);
+
+  dom = dds_create_domain (2,
+                           "<"DDS_PROJECT_NAME"><Domain><Id>any</Id></Domain>"
+                           "<DDSI2E><Internal><MaxParticipants>2</MaxParticipants></Internal></DDSI2E>"
+                           "</"DDS_PROJECT_NAME">");
+  CU_ASSERT_FATAL (dom > 0);
+
+  /* 2nd attempt at creating the same domain should fail */
+  CU_ASSERT_FATAL (dds_create_domain (2, "") == DDS_RETCODE_PRECONDITION_NOT_MET);
+
+  dds_delete (dom);
 }
diff --git a/src/core/ddsc/tests/entity_hierarchy.c b/src/core/ddsc/tests/entity_hierarchy.c
index 7983011..04f7f96 100644
--- a/src/core/ddsc/tests/entity_hierarchy.c
+++ b/src/core/ddsc/tests/entity_hierarchy.c
@@ -192,6 +192,10 @@ CU_Test(ddsc_entity_delete, recursive_with_deleted_topic)
     ret = dds_delete(g_topic);
     CU_ASSERT_EQUAL_FATAL(ret, DDS_RETCODE_OK);
 
+    /* Second call to delete a topic must fail */
+    ret = dds_delete(g_topic);
+    CU_ASSERT_EQUAL_FATAL(ret, DDS_RETCODE_ALREADY_DELETED);
+
     /* Third, deleting the participant should delete all children of which
      * the writer with the last topic reference is one. */
     ret = dds_delete(g_participant);