1 files changed, 48 insertions, 50 deletions

diff --git a/database/engine/rrdengineapi.c b/database/engine/rrdengineapi.c
index 27503baee..4525b041f 100755
--- a/database/engine/rrdengineapi.c
+++ b/database/engine/rrdengineapi.c
@@ -39,21 +39,35 @@ uint8_t rrdeng_drop_metrics_under_page_cache_pressure = 1;
 // ----------------------------------------------------------------------------
 // metrics groups
 
+static inline void rrdeng_page_alignment_acquire(struct pg_alignment *pa) {
+    if(unlikely(!pa)) return;
+    __atomic_add_fetch(&pa->refcount, 1, __ATOMIC_SEQ_CST);
+}
+
+static inline bool rrdeng_page_alignment_release(struct pg_alignment *pa) {
+    if(unlikely(!pa)) return true;
+
+    if(__atomic_sub_fetch(&pa->refcount, 1, __ATOMIC_SEQ_CST) == 0) {
+        freez(pa);
+        return true;
+    }
+
+    return false;
+}
+
+// charts call this
 STORAGE_METRICS_GROUP *rrdeng_metrics_group_get(STORAGE_INSTANCE *db_instance __maybe_unused, uuid_t *uuid __maybe_unused) {
-    return callocz(1, sizeof(struct pg_alignment));
+    struct pg_alignment *pa = callocz(1, sizeof(struct pg_alignment));
+    rrdeng_page_alignment_acquire(pa);
+    return (STORAGE_METRICS_GROUP *)pa;
 }
 
-void rrdeng_metrics_group_release(STORAGE_INSTANCE *db_instance, STORAGE_METRICS_GROUP *smg) {
-    if(!smg) return;
+// charts call this
+void rrdeng_metrics_group_release(STORAGE_INSTANCE *db_instance __maybe_unused, STORAGE_METRICS_GROUP *smg) {
+    if(unlikely(!smg)) return;
 
-    struct rrdengine_instance *ctx = (struct rrdengine_instance *)db_instance;
     struct pg_alignment *pa = (struct pg_alignment *)smg;
-    struct page_cache *pg_cache = &ctx->pg_cache;
-
-    uv_rwlock_rdlock(&pg_cache->metrics_index.lock);
-    if(pa->refcount == 0)
-        freez(pa);
-    uv_rwlock_rdunlock(&pg_cache->metrics_index.lock);
+    rrdeng_page_alignment_release(pa);
 }
 
 // ----------------------------------------------------------------------------
@@ -93,10 +107,10 @@ void rrdeng_convert_legacy_uuid_to_multihost(char machine_guid[GUID_LEN + 1], uu
     memcpy(ret_uuid, hash_value, sizeof(uuid_t));
 }
 
-STORAGE_METRIC_HANDLE *rrdeng_metric_get_legacy(STORAGE_INSTANCE *db_instance, const char *rd_id, const char *st_id, STORAGE_METRICS_GROUP *smg) {
+STORAGE_METRIC_HANDLE *rrdeng_metric_get_legacy(STORAGE_INSTANCE *db_instance, const char *rd_id, const char *st_id) {
     uuid_t legacy_uuid;
     rrdeng_generate_legacy_uuid(rd_id, st_id, &legacy_uuid);
-    return rrdeng_metric_get(db_instance, &legacy_uuid, smg);
+    return rrdeng_metric_get(db_instance, &legacy_uuid);
 }
 
 // ----------------------------------------------------------------------------
@@ -105,11 +119,7 @@ STORAGE_METRIC_HANDLE *rrdeng_metric_get_legacy(STORAGE_INSTANCE *db_instance, c
 void rrdeng_metric_release(STORAGE_METRIC_HANDLE *db_metric_handle) {
     struct pg_cache_page_index *page_index = (struct pg_cache_page_index *)db_metric_handle;
 
-    unsigned short refcount = __atomic_sub_fetch(&page_index->refcount, 1, __ATOMIC_SEQ_CST);
-    if(refcount == 0 && page_index->alignment) {
-        __atomic_sub_fetch(&page_index->alignment->refcount, 1, __ATOMIC_SEQ_CST);
-        page_index->alignment = NULL;
-    }
+    __atomic_sub_fetch(&page_index->refcount, 1, __ATOMIC_SEQ_CST);
 }
 
 STORAGE_METRIC_HANDLE *rrdeng_metric_dup(STORAGE_METRIC_HANDLE *db_metric_handle) {
@@ -118,9 +128,8 @@ STORAGE_METRIC_HANDLE *rrdeng_metric_dup(STORAGE_METRIC_HANDLE *db_metric_handle
     return db_metric_handle;
 }
 
-STORAGE_METRIC_HANDLE *rrdeng_metric_get(STORAGE_INSTANCE *db_instance, uuid_t *uuid, STORAGE_METRICS_GROUP *smg) {
+STORAGE_METRIC_HANDLE *rrdeng_metric_get(STORAGE_INSTANCE *db_instance, uuid_t *uuid) {
     struct rrdengine_instance *ctx = (struct rrdengine_instance *)db_instance;
-    struct pg_alignment *pa = (struct pg_alignment *)smg;
     struct page_cache *pg_cache = &ctx->pg_cache;
     struct pg_cache_page_index *page_index = NULL;
 
@@ -130,27 +139,16 @@ STORAGE_METRIC_HANDLE *rrdeng_metric_get(STORAGE_INSTANCE *db_instance, uuid_t *
         page_index = *PValue;
     uv_rwlock_rdunlock(&pg_cache->metrics_index.lock);
 
-    if (likely(page_index)) {
+    if (likely(page_index))
         __atomic_add_fetch(&page_index->refcount, 1, __ATOMIC_SEQ_CST);
 
-        if(pa) {
-            if(page_index->alignment && page_index->alignment != pa && page_index->writers > 0)
-                fatal("DBENGINE: page_index has a different alignment (page_index refcount is %u, writers is %u).",
-                        page_index->refcount, page_index->writers);
-
-            page_index->alignment = pa;
-            __atomic_add_fetch(&pa->refcount, 1, __ATOMIC_SEQ_CST);
-        }
-    }
-
     return (STORAGE_METRIC_HANDLE *)page_index;
 }
 
-STORAGE_METRIC_HANDLE *rrdeng_metric_create(STORAGE_INSTANCE *db_instance, uuid_t *uuid, STORAGE_METRICS_GROUP *smg) {
+STORAGE_METRIC_HANDLE *rrdeng_metric_create(STORAGE_INSTANCE *db_instance, uuid_t *uuid) {
     internal_fatal(!db_instance, "DBENGINE: db_instance is NULL");
 
     struct rrdengine_instance *ctx = (struct rrdengine_instance *)db_instance;
-    struct pg_alignment *pa = (struct pg_alignment *)smg;
     struct pg_cache_page_index *page_index;
     struct page_cache *pg_cache = &ctx->pg_cache;
 
@@ -160,28 +158,25 @@ STORAGE_METRIC_HANDLE *rrdeng_metric_create(STORAGE_INSTANCE *db_instance, uuid_
     *PValue = page_index = create_page_index(uuid, ctx);
     page_index->prev = pg_cache->metrics_index.last_page_index;
     pg_cache->metrics_index.last_page_index = page_index;
-    page_index->alignment = pa;
     page_index->refcount = 1;
-    if(pa)
-        pa->refcount++;
     uv_rwlock_wrunlock(&pg_cache->metrics_index.lock);
 
     return (STORAGE_METRIC_HANDLE *)page_index;
 }
 
-STORAGE_METRIC_HANDLE *rrdeng_metric_get_or_create(RRDDIM *rd, STORAGE_INSTANCE *db_instance, STORAGE_METRICS_GROUP *smg) {
+STORAGE_METRIC_HANDLE *rrdeng_metric_get_or_create(RRDDIM *rd, STORAGE_INSTANCE *db_instance) {
     STORAGE_METRIC_HANDLE *db_metric_handle;
 
-    db_metric_handle = rrdeng_metric_get(db_instance, &rd->metric_uuid, smg);
+    db_metric_handle = rrdeng_metric_get(db_instance, &rd->metric_uuid);
     if(!db_metric_handle) {
-        db_metric_handle = rrdeng_metric_get_legacy(db_instance, rrddim_id(rd), rrdset_id(rd->rrdset), smg);
+        db_metric_handle = rrdeng_metric_get_legacy(db_instance, rrddim_id(rd), rrdset_id(rd->rrdset));
         if(db_metric_handle) {
             struct pg_cache_page_index *page_index = (struct pg_cache_page_index *)db_metric_handle;
             uuid_copy(rd->metric_uuid, page_index->id);
         }
     }
     if(!db_metric_handle)
-        db_metric_handle = rrdeng_metric_create(db_instance, &rd->metric_uuid, smg);
+        db_metric_handle = rrdeng_metric_create(db_instance, &rd->metric_uuid);
 
 #ifdef NETDATA_INTERNAL_CHECKS
     struct pg_cache_page_index *page_index = (struct pg_cache_page_index *)db_metric_handle;
@@ -210,19 +205,19 @@ STORAGE_METRIC_HANDLE *rrdeng_metric_get_or_create(RRDDIM *rd, STORAGE_INSTANCE
  * Gets a handle for storing metrics to the database.
  * The handle must be released with rrdeng_store_metric_final().
  */
-STORAGE_COLLECT_HANDLE *rrdeng_store_metric_init(STORAGE_METRIC_HANDLE *db_metric_handle, uint32_t update_every) {
+STORAGE_COLLECT_HANDLE *rrdeng_store_metric_init(STORAGE_METRIC_HANDLE *db_metric_handle, uint32_t update_every, STORAGE_METRICS_GROUP *smg) {
     struct pg_cache_page_index *page_index = (struct pg_cache_page_index *)db_metric_handle;
     struct rrdeng_collect_handle *handle;
 
-    if(!page_index->alignment)
-        fatal("DBENGINE: metric group is required for collect operations");
-
     handle = callocz(1, sizeof(struct rrdeng_collect_handle));
     handle->page_index = page_index;
     handle->descr = NULL;
     handle->unaligned_page = 0;
     page_index->latest_update_every_s = update_every;
 
+    handle->alignment = (struct pg_alignment *)smg;
+    rrdeng_page_alignment_acquire(handle->alignment);
+
     uv_rwlock_wrlock(&page_index->lock);
     ++page_index->writers;
     uv_rwlock_wrunlock(&page_index->lock);
@@ -331,18 +326,18 @@ static void rrdeng_store_metric_next_internal(STORAGE_COLLECT_HANDLE *collection
         }
 #endif
 
-        if (descr->page_length == page_index->alignment->page_length) {
+        if (descr->page_length == handle->alignment->page_length) {
             /* this is the leading dimension that defines chart alignment */
             perfect_page_alignment = 1;
         }
         /* is the metric far enough out of alignment with the others? */
-        if (unlikely(descr->page_length + PAGE_POINT_SIZE_BYTES(descr) < page_index->alignment->page_length)) {
+        if (unlikely(descr->page_length + PAGE_POINT_SIZE_BYTES(descr) < handle->alignment->page_length)) {
             handle->unaligned_page = 1;
             print_page_cache_descr(descr, "Metric page is not aligned with chart", true);
         }
         if (unlikely(handle->unaligned_page &&
                      /* did the other metrics change page? */
-                     page_index->alignment->page_length <= PAGE_POINT_SIZE_BYTES(descr))) {
+                     handle->alignment->page_length <= PAGE_POINT_SIZE_BYTES(descr))) {
             print_page_cache_descr(descr, "must_flush_unaligned_page = 1", true);
             must_flush_unaligned_page = 1;
             handle->unaligned_page = 0;
@@ -365,7 +360,7 @@ static void rrdeng_store_metric_next_internal(STORAGE_COLLECT_HANDLE *collection
 
         handle->page_correlation_id = rrd_atomic_fetch_add(&pg_cache->committed_page_index.latest_corr_id, 1);
 
-        if (0 == page_index->alignment->page_length) {
+        if (0 == handle->alignment->page_length) {
             /* this is the leading dimension that defines chart alignment */
             perfect_page_alignment = 1;
         }
@@ -403,7 +398,7 @@ static void rrdeng_store_metric_next_internal(STORAGE_COLLECT_HANDLE *collection
     pg_cache_atomic_set_pg_info(descr, point_in_time_ut, descr->page_length + PAGE_POINT_SIZE_BYTES(descr));
 
     if (perfect_page_alignment)
-        page_index->alignment->page_length = descr->page_length;
+        handle->alignment->page_length = descr->page_length;
     if (unlikely(INVALID_TIME == descr->start_time_ut)) {
         unsigned long new_metric_API_producers, old_metric_API_max_producers, ret_metric_API_max_producers;
         descr->start_time_ut = point_in_time_ut;
@@ -530,10 +525,13 @@ int rrdeng_store_metric_finalize(STORAGE_COLLECT_HANDLE *collection_handle) {
 
     rrdeng_store_metric_flush_current_page(collection_handle);
     uv_rwlock_wrlock(&page_index->lock);
-    if (!--page_index->writers && !page_index->page_count) {
+
+    if (!--page_index->writers && !page_index->page_count)
         can_delete_metric = 1;
-    }
+
     uv_rwlock_wrunlock(&page_index->lock);
+
+    rrdeng_page_alignment_release(handle->alignment);
     freez(handle);
 
     return can_delete_metric;