[td-225] fix invalid read when free taosCache object.

src/client/src/tscSystem.c

@@ -143,11 +143,11 @@ void taos_init_imp() {
   }
   
   int64_t refreshTime = tsTableMetaKeepTimer;
-  refreshTime = refreshTime > 2 ? 2 : refreshTime;
-  refreshTime = refreshTime < 1 ? 1 : refreshTime;
+  refreshTime = refreshTime > 10 ? 10 : refreshTime;
+  refreshTime = refreshTime < 10 ? 10 : refreshTime;
 
   if (tscCacheHandle == NULL) {
-    tscCacheHandle = taosCacheInit(tscTmr, refreshTime);
+    tscCacheHandle = taosCacheInit(refreshTime);
   }
 
   tscTrace("client is initialized successfully");

src/mnode/src/mnodeProfile.c

@@ -67,7 +67,7 @@ int32_t mnodeInitProfile() {
   mnodeAddWriteMsgHandle(TSDB_MSG_TYPE_CM_KILL_STREAM, mnodeProcessKillStreamMsg);
   mnodeAddWriteMsgHandle(TSDB_MSG_TYPE_CM_KILL_CONN, mnodeProcessKillConnectionMsg);
 
-  tsMnodeConnCache = taosCacheInitWithCb(tsMnodeTmr, CONN_CHECK_TIME, mnodeFreeConn);
+  tsMnodeConnCache = taosCacheInitWithCb(CONN_CHECK_TIME, mnodeFreeConn);
   return 0;
 }
 

src/mnode/src/mnodeShow.c

@@ -65,7 +65,7 @@ int32_t mnodeInitShow() {
   mnodeAddReadMsgHandle(TSDB_MSG_TYPE_CM_CONNECT, mnodeProcessConnectMsg);
   mnodeAddReadMsgHandle(TSDB_MSG_TYPE_CM_USE_DB, mnodeProcessUseMsg);
   
-  tsMnodeShowCache = taosCacheInitWithCb(tsMnodeTmr, 10, mnodeFreeShowObj);
+  tsMnodeShowCache = taosCacheInitWithCb(10, mnodeFreeShowObj);
   return 0;
 }
 

src/util/inc/tcache.h

@@ -37,8 +37,8 @@ typedef struct SCacheDataNode {
   uint64_t expiredTime;  // expiredTime expiredTime when this element should be remove from cache
   uint64_t signature;
   uint32_t size;         // allocated size for current SCacheDataNode
-  uint16_t keySize : 15;
-  bool     inTrash : 1;  // denote if it is in trash or not
+  uint16_t keySize: 15;
+  bool     inTrashCan: 1;// denote if it is in trash or not
   T_REF_DECLARE()
   char *key;
   char  data[];
@@ -50,46 +50,49 @@ typedef struct STrashElem {
   SCacheDataNode    *pData;
 } STrashElem;
 
+/*
+ * to accommodate the old data which has the same key value of new one in hashList
+ * when an new node is put into cache, if an existed one with the same key:
+ * 1. if the old one does not be referenced, update it.
+ * 2. otherwise, move the old one to pTrash, addedTime the new one.
+ *
+ * when the node in pTrash does not be referenced, it will be release at the expired expiredTime
+ */
 typedef struct {
-  int64_t totalSize;  // total allocated buffer in this hash table, SCacheObj is not included.
-  int64_t refreshTime;
-  
-  /*
-   * to accommodate the old datanode which has the same key value of new one in hashList
-   * when an new node is put into cache, if an existed one with the same key:
-   * 1. if the old one does not be referenced, update it.
-   * 2. otherwise, move the old one to pTrash, addedTime the new one.
-   *
-   * when the node in pTrash does not be referenced, it will be release at the expired expiredTime
-   */
-  STrashElem * pTrash;
-  void *       tmrCtrl;
-  void *       pTimer;
-  SCacheStatis statistics;
-  SHashObj *   pHashTable;
+  int64_t         totalSize;          // total allocated buffer in this hash table, SCacheObj is not included.
+  int64_t         refreshTime;
+  STrashElem *    pTrash;
+  void *          tmrCtrl;
+  void *          pTimer;
+  SCacheStatis    statistics;
+  SHashObj *      pHashTable;
   _hash_free_fn_t freeFp;
-  int          numOfElemsInTrash;  // number of element in trash
-  int16_t      deleting;           // set the deleting flag to stop refreshing ASAP.
-  T_REF_DECLARE()
+  uint32_t        numOfElemsInTrash;  // number of element in trash
+  uint8_t         deleting;           // set the deleting flag to stop refreshing ASAP.
+  pthread_t       refreshWorker;
 
 #if defined(LINUX)
   pthread_rwlock_t lock;
 #else
   pthread_mutex_t lock;
 #endif
-
 } SCacheObj;
 
 /**
- *
- * @param maxSessions       maximum slots available for hash elements
- * @param tmrCtrl           timer ctrl
+ * initialize the cache object
  * @param refreshTime       refresh operation interval time, the maximum survival time when one element is expired and
  *                          not referenced by other objects
  * @return
  */
-SCacheObj *taosCacheInit(void *tmrCtrl, int64_t refreshTimeInSeconds);
-SCacheObj *taosCacheInitWithCb(void *tmrCtrl, int64_t refreshTimeInSeconds, void (*freeCb)(void *data));
+SCacheObj *taosCacheInit(int64_t refreshTimeInSeconds);
+
+/**
+ * initialize the cache object and set the free object callback function
+ * @param refreshTimeInSeconds
+ * @param freeCb
+ * @return
+ */
+SCacheObj *taosCacheInitWithCb(int64_t refreshTimeInSeconds, void (*freeCb)(void *data));
 
 /**
  * add data into cache

src/util/src/tcache.c

@@ -77,31 +77,7 @@ static FORCE_INLINE void taosFreeNode(void *data) {
  * @param lifespan total survial expiredTime from now
  * @return         SCacheDataNode
  */
-static SCacheDataNode *taosCreateCacheNode(const char *key, size_t keyLen, const char *pData, size_t size,
-                                          uint64_t duration) {
-  size_t totalSize = size + sizeof(SCacheDataNode) + keyLen + 1;
-  
-  SCacheDataNode *pNewNode = calloc(1, totalSize);
-  if (pNewNode == NULL) {
-    uError("failed to allocate memory, reason:%s", strerror(errno));
-    return NULL;
-  }
-  
-  memcpy(pNewNode->data, pData, size);
-  
-  pNewNode->key = (char *)pNewNode + sizeof(SCacheDataNode) + size;
-  pNewNode->keySize = keyLen;
-  
-  memcpy(pNewNode->key, key, keyLen);
-  
-  pNewNode->addedTime = (uint64_t)taosGetTimestampMs();
-  pNewNode->expiredTime = pNewNode->addedTime + duration;
-  
-  pNewNode->signature = (uint64_t)pNewNode;
-  pNewNode->size = (uint32_t)totalSize;
-  
-  return pNewNode;
-}
+static SCacheDataNode *taosCreateCacheNode(const char *key, size_t keyLen, const char *pData, size_t size, uint64_t duration);
 
 /**
  * addedTime object node into trash, and this object is closed for referencing if it is addedTime to trash
@@ -109,50 +85,15 @@ static SCacheDataNode *taosCreateCacheNode(const char *key, size_t keyLen, const
  * @param pCacheObj    Cache object
  * @param pNode   Cache slot object
  */
-static void taosAddToTrash(SCacheObj *pCacheObj, SCacheDataNode *pNode) {
-  if (pNode->inTrash) { /* node is already in trash */
-    return;
-  }
-  
-  STrashElem *pElem = calloc(1, sizeof(STrashElem));
-  pElem->pData = pNode;
-  
-  pElem->next = pCacheObj->pTrash;
-  if (pCacheObj->pTrash) {
-    pCacheObj->pTrash->prev = pElem;
-  }
-  
-  pElem->prev = NULL;
-  pCacheObj->pTrash = pElem;
-  
-  pNode->inTrash = true;
-  pCacheObj->numOfElemsInTrash++;
-  
-  uTrace("key:%s %p move to trash, numOfElem in trash:%d", pNode->key, pNode, pCacheObj->numOfElemsInTrash);
-}
+static void taosAddToTrash(SCacheObj *pCacheObj, SCacheDataNode *pNode);
+
+/**
+ * remove node in trash can
+ * @param pCacheObj 
+ * @param pElem 
+ */
+static void taosRemoveFromTrashCan(SCacheObj *pCacheObj, STrashElem *pElem);
 
-static void taosRemoveFromTrash(SCacheObj *pCacheObj, STrashElem *pElem) {
-  if (pElem->pData->signature != (uint64_t)pElem->pData) {
-    uError("key:sig:%d %p data has been released, ignore", pElem->pData->signature, pElem->pData);
-    return;
-  }
-  
-  pCacheObj->numOfElemsInTrash--;
-  if (pElem->prev) {
-    pElem->prev->next = pElem->next;
-  } else { /* pnode is the header, update header */
-    pCacheObj->pTrash = pElem->next;
-  }
-  
-  if (pElem->next) {
-    pElem->next->prev = pElem->prev;
-  }
-  
-  pElem->pData->signature = 0;
-  if (pCacheObj->freeFp) pCacheObj->freeFp(pElem->pData->data);
-  free(pElem->pData);
-  free(pElem);
-}
 /**
  * remove nodes in trash with refCount == 0 in cache
  * @param pNode
@@ -160,42 +101,7 @@ static void taosRemoveFromTrash(SCacheObj *pCacheObj, STrashElem *pElem) {
  * @param force   force model, if true, remove data in trash without check refcount.
  *                may cause corruption. So, forece model only applys before cache is closed
  */
-static void taosTrashEmpty(SCacheObj *pCacheObj, bool force) {
-  __cache_wr_lock(pCacheObj);
-  
-  if (pCacheObj->numOfElemsInTrash == 0) {
-    if (pCacheObj->pTrash != NULL) {
-      uError("key:inconsistency data in cache, numOfElem in trash:%d", pCacheObj->numOfElemsInTrash);
-    }
-    pCacheObj->pTrash = NULL;
-    
-    __cache_unlock(pCacheObj);
-    return;
-  }
-  
-  STrashElem *pElem = pCacheObj->pTrash;
-  
-  while (pElem) {
-    T_REF_VAL_CHECK(pElem->pData);
-    if (pElem->next == pElem) {
-      pElem->next = NULL;
-    }
-    
-    if (force || (T_REF_VAL_GET(pElem->pData) == 0)) {
-      uTrace("key:%s %p removed from trash. numOfElem in trash:%d", pElem->pData->key, pElem->pData,
-             pCacheObj->numOfElemsInTrash - 1);
-      STrashElem *p = pElem;
-      
-      pElem = pElem->next;
-      taosRemoveFromTrash(pCacheObj, p);
-    } else {
-      pElem = pElem->next;
-    }
-  }
-  
-  assert(pCacheObj->numOfElemsInTrash >= 0);
-  __cache_unlock(pCacheObj);
-}
+static void taosTrashCanEmpty(SCacheObj *pCacheObj, bool force);
 
 /**
  * release node
@@ -304,87 +210,20 @@ static FORCE_INLINE SCacheDataNode *taosAddToCacheImpl(SCacheObj *pCacheObj, con
   return pNode;
 }
 
-static void doCleanupDataCache(SCacheObj *pCacheObj) {
-  __cache_wr_lock(pCacheObj);
-  
-  //if (taosHashGetSize(pCacheObj->pHashTable) > 0) {
-  taosHashCleanup(pCacheObj->pHashTable);
-  //}
-  
-  __cache_unlock(pCacheObj);
-  
-  taosTrashEmpty(pCacheObj, true);
-  __cache_lock_destroy(pCacheObj);
-  
-  memset(pCacheObj, 0, sizeof(SCacheObj));
-  free(pCacheObj);
-}
+/**
+ * do cleanup the taos cache
+ * @param pCacheObj
+ */
+static void doCleanupDataCache(SCacheObj *pCacheObj);
 
 /**
  * refresh cache to remove data in both hash list and trash, if any nodes' refcount == 0, every pCacheObj->refreshTime
  * @param handle   Cache object handle
  */
-static void taosCacheRefresh(void *handle, void *tmrId) {
-  SCacheObj *pCacheObj = (SCacheObj *)handle;
-  
-  if (pCacheObj == NULL || T_REF_VAL_GET(pCacheObj) == 0) {
-    uTrace("object is destroyed. no refresh retry");
-    return;
-  }
-  
-  int16_t ref = T_REF_INC(pCacheObj);
-  if (ref == 1) {
-    T_REF_DEC(pCacheObj);
-    return;
-  }
-  
-  // todo add the ref before start the timer
-  int32_t num = taosHashGetSize(pCacheObj->pHashTable);
-  if (num == 0) {
-    ref = T_REF_DEC(pCacheObj);
-    if (ref == 0) {
-      doCleanupDataCache(pCacheObj);
-    } else {
-      taosTmrReset(taosCacheRefresh, pCacheObj->refreshTime, pCacheObj, pCacheObj->tmrCtrl, &pCacheObj->pTimer);
-    }
-    return;
-  }
-  
-  uint64_t expiredTime = taosGetTimestampMs();
-  pCacheObj->statistics.refreshCount++;
-  
-  SHashMutableIterator *pIter = taosHashCreateIter(pCacheObj->pHashTable);
-  
-  __cache_wr_lock(pCacheObj);
-  while (taosHashIterNext(pIter)) {
-    if (pCacheObj->deleting == 1) {
-      taosHashDestroyIter(pIter);
-      break;
-    }
-    
-    SCacheDataNode *pNode = *(SCacheDataNode **)taosHashIterGet(pIter);
-    if (pNode->expiredTime <= expiredTime && T_REF_VAL_GET(pNode) <= 0) {
-      taosCacheReleaseNode(pCacheObj, pNode);
-    }
-  }
-  
-  __cache_unlock(pCacheObj);
-  
-  taosHashDestroyIter(pIter);
+static void* taosCacheRefresh(void *handle);
 
-    taosTrashEmpty(pCacheObj, false);
-    
-    ref = T_REF_DEC(pCacheObj);
-    if (ref == 0)  {
-      doCleanupDataCache(pCacheObj);
-      return;
-    } else {
-      taosTmrReset(taosCacheRefresh, pCacheObj->refreshTime, pCacheObj, pCacheObj->tmrCtrl, &pCacheObj->pTimer);
-    }
-}
-
-SCacheObj *taosCacheInitWithCb(void *tmrCtrl, int64_t refreshTime, void (*freeCb)(void *data)) {
-  if (tmrCtrl == NULL || refreshTime <= 0) {
+SCacheObj *taosCacheInitWithCb(int64_t refreshTime, void (*freeCb)(void *data)) {
+  if (refreshTime <= 0) {
     return NULL;
   }
   
@@ -394,7 +233,7 @@ SCacheObj *taosCacheInitWithCb(void *tmrCtrl, int64_t refreshTime, void (*freeCb
     return NULL;
   }
   
-  pCacheObj->pHashTable = taosHashInit(1024, taosGetDefaultHashFunction(TSDB_DATA_TYPE_BINARY), false);
+  pCacheObj->pHashTable = taosHashInit(128, taosGetDefaultHashFunction(TSDB_DATA_TYPE_BINARY), false);
   if (pCacheObj->pHashTable == NULL) {
     free(pCacheObj);
     uError("failed to allocate memory, reason:%s", strerror(errno));
@@ -406,25 +245,27 @@ SCacheObj *taosCacheInitWithCb(void *tmrCtrl, int64_t refreshTime, void (*freeCb
   
   pCacheObj->freeFp = freeCb;
   pCacheObj->refreshTime = refreshTime * 1000;
-  pCacheObj->tmrCtrl = tmrCtrl;
-  
-  taosTmrReset(taosCacheRefresh, pCacheObj->refreshTime, pCacheObj, pCacheObj->tmrCtrl, &pCacheObj->pTimer);
-  
+
   if (__cache_lock_init(pCacheObj) != 0) {
-    taosTmrStopA(&pCacheObj->pTimer);
     taosHashCleanup(pCacheObj->pHashTable);
     free(pCacheObj);
     
     uError("failed to init lock, reason:%s", strerror(errno));
     return NULL;
   }
-  
-  T_REF_INC(pCacheObj);
+
+  pthread_attr_t thattr = {0};
+  pthread_attr_init(&thattr);
+  pthread_attr_setdetachstate(&thattr, PTHREAD_CREATE_JOINABLE);
+
+  pthread_create(&pCacheObj->refreshWorker, &thattr, taosCacheRefresh, pCacheObj);
+
+  pthread_attr_destroy(&thattr);
   return pCacheObj;
 }
 
-SCacheObj *taosCacheInit(void *tmrCtrl, int64_t refreshTime) {
-  return taosCacheInitWithCb(tmrCtrl, refreshTime, NULL);
+SCacheObj *taosCacheInit(int64_t refreshTime) {
+  return taosCacheInitWithCb(refreshTime, NULL);
 }
 
 void *taosCachePut(SCacheObj *pCacheObj, const char *key, const void *pData, size_t dataSize, int duration) {
@@ -600,16 +441,188 @@ void taosCacheEmpty(SCacheObj *pCacheObj) {
   __cache_unlock(pCacheObj);
   
   taosHashDestroyIter(pIter);
-  taosTrashEmpty(pCacheObj, false);
+  taosTrashCanEmpty(pCacheObj, false);
 }
 
 void taosCacheCleanup(SCacheObj *pCacheObj) {
   if (pCacheObj == NULL) {
     return;
   }
-  
-  int32_t ref = T_REF_DEC(pCacheObj);
-  if (ref == 0) {
-    doCleanupDataCache(pCacheObj);
+
+  pCacheObj->deleting = 1;
+  pthread_join(pCacheObj->refreshWorker, NULL);
+
+  doCleanupDataCache(pCacheObj);
+}
+
+SCacheDataNode *taosCreateCacheNode(const char *key, size_t keyLen, const char *pData, size_t size,
+                                           uint64_t duration) {
+  size_t totalSize = size + sizeof(SCacheDataNode) + keyLen + 1;
+
+  SCacheDataNode *pNewNode = calloc(1, totalSize);
+  if (pNewNode == NULL) {
+    uError("failed to allocate memory, reason:%s", strerror(errno));
+    return NULL;
+  }
+
+  memcpy(pNewNode->data, pData, size);
+
+  pNewNode->key = (char *)pNewNode + sizeof(SCacheDataNode) + size;
+  pNewNode->keySize = keyLen;
+
+  memcpy(pNewNode->key, key, keyLen);
+
+  pNewNode->addedTime = (uint64_t)taosGetTimestampMs();
+  pNewNode->expiredTime = pNewNode->addedTime + duration;
+
+  pNewNode->signature = (uint64_t)pNewNode;
+  pNewNode->size = (uint32_t)totalSize;
+
+  return pNewNode;
+}
+
+void taosAddToTrash(SCacheObj *pCacheObj, SCacheDataNode *pNode) {
+  if (pNode->inTrashCan) { /* node is already in trash */
+    return;
+  }
+
+  STrashElem *pElem = calloc(1, sizeof(STrashElem));
+  pElem->pData = pNode;
+
+  pElem->next = pCacheObj->pTrash;
+  if (pCacheObj->pTrash) {
+    pCacheObj->pTrash->prev = pElem;
+  }
+
+  pElem->prev = NULL;
+  pCacheObj->pTrash = pElem;
+
+  pNode->inTrashCan = true;
+  pCacheObj->numOfElemsInTrash++;
+
+  uTrace("key:%s %p move to trash, numOfElem in trash:%d", pNode->key, pNode, pCacheObj->numOfElemsInTrash);
+}
+
+void taosRemoveFromTrashCan(SCacheObj *pCacheObj, STrashElem *pElem) {
+  if (pElem->pData->signature != (uint64_t)pElem->pData) {
+    uError("key:sig:%d %p data has been released, ignore", pElem->pData->signature, pElem->pData);
+    return;
+  }
+
+  pCacheObj->numOfElemsInTrash--;
+  if (pElem->prev) {
+    pElem->prev->next = pElem->next;
+  } else { /* pnode is the header, update header */
+    pCacheObj->pTrash = pElem->next;
+  }
+
+  if (pElem->next) {
+    pElem->next->prev = pElem->prev;
+  }
+
+  pElem->pData->signature = 0;
+  if (pCacheObj->freeFp) pCacheObj->freeFp(pElem->pData->data);
+  free(pElem->pData);
+  free(pElem);
+}
+
+void taosTrashCanEmpty(SCacheObj *pCacheObj, bool force) {
+  __cache_wr_lock(pCacheObj);
+
+  if (pCacheObj->numOfElemsInTrash == 0) {
+    if (pCacheObj->pTrash != NULL) {
+      uError("key:inconsistency data in cache, numOfElem in trash:%d", pCacheObj->numOfElemsInTrash);
+    }
+    pCacheObj->pTrash = NULL;
+
+    __cache_unlock(pCacheObj);
+    return;
   }
+
+  STrashElem *pElem = pCacheObj->pTrash;
+
+  while (pElem) {
+    T_REF_VAL_CHECK(pElem->pData);
+    if (pElem->next == pElem) {
+      pElem->next = NULL;
+    }
+
+    if (force || (T_REF_VAL_GET(pElem->pData) == 0)) {
+      uTrace("key:%s %p removed from trash. numOfElem in trash:%d", pElem->pData->key, pElem->pData,
+             pCacheObj->numOfElemsInTrash - 1);
+      STrashElem *p = pElem;
+
+      pElem = pElem->next;
+      taosRemoveFromTrashCan(pCacheObj, p);
+    } else {
+      pElem = pElem->next;
+    }
+  }
+
+  assert(pCacheObj->numOfElemsInTrash >= 0);
+  __cache_unlock(pCacheObj);
+}
+
+void doCleanupDataCache(SCacheObj *pCacheObj) {
+  __cache_wr_lock(pCacheObj);
+  taosHashCleanup(pCacheObj->pHashTable);
+  __cache_unlock(pCacheObj);
+
+  taosTrashCanEmpty(pCacheObj, true);
+  __cache_lock_destroy(pCacheObj);
+
+  memset(pCacheObj, 0, sizeof(SCacheObj));
+  free(pCacheObj);
 }
+
+void* taosCacheRefresh(void *handle) {
+  SCacheObj *pCacheObj = (SCacheObj *)handle;
+  if (pCacheObj == NULL) {
+    uTrace("object is destroyed. no refresh retry");
+    return NULL;
+  }
+
+  const int32_t SLEEP_DURATION = 500; //500 ms
+  int64_t totalTick = pCacheObj->refreshTime / SLEEP_DURATION;
+
+  int64_t count = 0;
+  while(1) {
+    taosMsleep(500);
+
+    // check if current cache object will be deleted every 500ms.
+    if (pCacheObj->deleting) {
+      break;
+    }
+
+    if (++count < totalTick) {
+      continue;
+    }
+
+    // reset the count value
+    count = 0;
+    size_t num = taosHashGetSize(pCacheObj->pHashTable);
+    if (num == 0) {
+      continue;
+    }
+
+    uint64_t expiredTime = taosGetTimestampMs();
+    pCacheObj->statistics.refreshCount++;
+
+    SHashMutableIterator *pIter = taosHashCreateIter(pCacheObj->pHashTable);
+
+    __cache_wr_lock(pCacheObj);
+    while (taosHashIterNext(pIter)) {
+      SCacheDataNode *pNode = *(SCacheDataNode **)taosHashIterGet(pIter);
+      if (pNode->expiredTime <= expiredTime && T_REF_VAL_GET(pNode) <= 0) {
+        taosCacheReleaseNode(pCacheObj, pNode);
+      }
+    }
+
+    __cache_unlock(pCacheObj);
+
+    taosHashDestroyIter(pIter);
+    taosTrashCanEmpty(pCacheObj, false);
+  }
+
+  return NULL;
+}
\ No newline at end of file