Merge pull request #287 from universeroc/master

Check memory allocation after malloc

documentation/tdenginedocs-en/advanced-features/index.html

@@ -29,7 +29,7 @@ INTERVAL(1M) SLIDING(30S) </code></pre></li>
 <p>Inside TDengine shell, you can use the command "show streams" to list the ongoing continuous queries, the command "kill stream" to kill a specific continuous query. </p>
 <p>If you drop a table generated by the continuous query, the query will be removed too.</p>
 <a class='anchor' id='Publisher/Subscriber'></a><h2>Publisher/Subscriber</h2>
-<p>Time series data is a sequence of data points over time. Inside a table, the data points are stored in order of timestamp. Also, there is a data retention policy, the data points will be removed once their lifetime is passed. From another view, a table in DTengine is just a standard message queue. </p>
+<p>Time series data is a sequence of data points over time. Inside a table, the data points are stored in order of timestamp. Also, there is a data retention policy, the data points will be removed once their lifetime is passed. From another view, a table in TDengine is just a standard message queue. </p>
 <p>To reduce the development complexity and improve data consistency, TDengine provides the pub/sub functionality. To publish a message, you simply insert a record into a table. Compared with popular messaging tool Kafka, you subscribe to a table or a SQL query statement, instead of a topic. Once new data points arrive, TDengine will notify the application. The process is just like Kafka.  </p>
 <p>The detailed API will be introduced in the <a href="https://www.taosdata.com/en/documentation/advanced-features/">connectors</a> section. </p>
 <a class='anchor' id='Caching'></a><h2>Caching</h2>

src/util/src/ihash.c

@@ -54,9 +54,12 @@ char *taosAddIntHash(void *handle, int32_t key, char *pData) {
 
   hash = (*pObj->hashFp)(pObj, key);
 
+  pNode = (IHashNode *)malloc(sizeof(IHashNode) + (size_t)pObj->dataSize);
+  if (pNode == NULL)
+    return NULL;
+  
   pthread_mutex_lock(&pObj->mutex);
 
-  pNode = (IHashNode *)malloc(sizeof(IHashNode) + (size_t)pObj->dataSize);
   pNode->key = key;
   if (pData != NULL) {
     memcpy(pNode->data, pData, (size_t)pObj->dataSize);