Fix issue of it sometimes crashed when cycle read datatag in modbus t…

…cp plugin
emqx · Dec 17, 2021 · a708814 · a708814
1 parent 4241829
commit a708814
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Showing 2 changed files with 23 additions and 0 deletions.
diff --git a/plugins/modbus/modbus_tcp.c b/plugins/modbus/modbus_tcp.c
@@ -104,6 +104,10 @@ static void start_periodic_read(neu_plugin_t *       plugin,
         neu_datatag_id_t *id  = (neu_datatag_id_t *) iterator_get(&iter);
         neu_datatag_t *   tag = neu_datatag_tbl_get(plugin->tag_table, *id);
 
+        if (tag == NULL) {
+            // The tag had been deleted by other node
+            continue;
+        }
         if ((tag->attribute & NEU_ATTRIBUTE_READ) == NEU_ATTRIBUTE_READ) {
             switch (tag->type) {
             case NEU_DTYPE_UINT16:
@@ -199,6 +203,11 @@ setup_read_resp_data_value(neu_datatag_table_t *   tag_table,
         int               result  = 0;
         neu_int_val_t     int_val = { 0 };
 
+        if (tag == NULL) {
+            // The tag had been deleted by other node
+            continue;
+        }
+
         if ((tag->attribute & NEU_ATTRIBUTE_READ) == NEU_ATTRIBUTE_READ) {
             switch (tag->type) {
             case NEU_DTYPE_UINT32:
@@ -343,6 +352,16 @@ static neu_data_val_t *setup_write_resp_data_value(neu_data_val_t *write_val,
         neu_datatag_t * tag =
             neu_datatag_tbl_get(plugin->tag_table, int_val->key);
 
+        if (tag == NULL) {
+            // The tag had been deleted by other node
+            error = NEU_ERR_TAG_NOT_EXIST;
+            neu_dvalue_set_errorcode(val_error, error);
+
+            neu_int_val_init(&iv, int_val->key, val_error);
+            neu_fixed_array_set(array_resp, i, (void *) &iv);
+            continue;
+        }
+
         switch (val_type) {
         case NEU_DTYPE_INT64: {
             int64_t i64 = 0;

diff --git a/src/base/neu_plugin_common.c b/src/base/neu_plugin_common.c
@@ -453,6 +453,10 @@ int neu_plugin_tag_count_by_attribute(neu_taggrp_config_t *grp_config,
     {
         neu_datatag_id_t *id  = (neu_datatag_id_t *) iterator_get(&iter_id);
         neu_datatag_t *   tag = neu_datatag_tbl_get(tag_table, *id);
+        if (tag == NULL) {
+            // The tag had been deleted by other node
+            continue;
+        }
         if ((tag->attribute & attribute) == attribute) {
             count += 1;
         }