more code

source/dnode/vnode/src/inc/vnd.h

@@ -62,6 +62,8 @@ struct SVBufPoolNode {
 
 struct SVBufPool {
   SVBufPool*        freeNext;
+  SVBufPool*        recycleNext;
+  SVBufPool*        recyclePrev;
   SVnode*           pVnode;
   TdThreadSpinlock* lock;
   volatile int32_t  nRef;

source/dnode/vnode/src/vnd/vnodeBufPool.c

@@ -69,8 +69,6 @@ static int vnodeBufPoolDestroy(SVBufPool *pPool) {
 int vnodeOpenBufPool(SVnode *pVnode) {
   int64_t size = pVnode->config.szBuf / VNODE_BUFPOOL_SEGMENTS;
 
-  ASSERT(pVnode->freeList == NULL);
-
   for (int i = 0; i < VNODE_BUFPOOL_SEGMENTS; i++) {
     // create pool
     if (vnodeBufPoolCreate(pVnode, size, &pVnode->aBufPool[i])) {

source/dnode/vnode/src/vnd/vnodeCommit.c

@@ -21,18 +21,48 @@
 static int vnodeEncodeInfo(const SVnodeInfo *pInfo, char **ppData);
 static int vnodeCommitImpl(SCommitInfo *pInfo);
 
+#define WAIT_TIME_MILI_SEC 10  // miliseconds
+
 int vnodeBegin(SVnode *pVnode) {
   // alloc buffer pool
   taosThreadMutexLock(&pVnode->mutex);
 
+  int32_t nTry = 0;
+  for (;;) {
     while (pVnode->freeList == NULL) {
-    taosThreadCondWait(&pVnode->poolNotEmpty, &pVnode->mutex);
+      vDebug("vgId:%d no free buffer pool, try to wait %d...", TD_VID(pVnode), ++nTry);
+
+      struct timeval  tv;
+      struct timespec ts;
+
+      taosGetTimeOfDay(&tv);
+      ts.tv_sec = tv.tv_sec;
+      ts.tv_nsec = tv.tv_usec * 1000 + WAIT_TIME_MILI_SEC * 1000000;
+
+      int32_t rc = taosThreadCondTimedWait(&pVnode->poolNotEmpty, &pVnode->mutex, &ts);
+      if (rc == ETIMEDOUT) {  // time out, break
+        break;
+      } else if (rc != 0) {  // error occurred
+        terrno = TAOS_SYSTEM_ERROR(rc);
+        vError("vgId:%d %s failed since %s", TD_VID(pVnode), __func__, tstrerror(terrno));
+        taosThreadMutexUnlock(&pVnode->mutex);
+        return -1;
+      }
     }
 
+    if (pVnode->freeList) {
+      // allocate from free list
       pVnode->inUse = pVnode->freeList;
       pVnode->inUse->nRef = 1;
       pVnode->freeList = pVnode->inUse->freeNext;
       pVnode->inUse->freeNext = NULL;
+      break;
+    } else if (nTry == 1) {
+      // try to recycle a buffer pool
+      vInfo("vgId:%d no free buffer pool, try to recycle...", TD_VID(pVnode));
+      ASSERT(false);  // TODO: condition of nTry == 1 may not be reasonable
+    }
+  }
 
   taosThreadMutexUnlock(&pVnode->mutex);