FIX on SleepQueue

Author: Coldwings

thread/thread.cpp

@@ -391,6 +391,7 @@ namespace photon
         // compare m_nodes[idx] with parent node.
         bool up(int idx)
         {
+            if (q.empty()) return false;
             auto tmp = q[idx];
             bool ret = false;
             while (idx != 0){
@@ -410,6 +411,7 @@ namespace photon
         // compare m_nodes[idx] with child node.
         bool down(int idx)
         {
+            if (q.empty()) return false;
             auto tmp = q[idx];
             size_t cmpIdx = (idx << 1) + 1;
             bool ret = false;