fix the core that sql nio send handshake packet failed and free ObSqlSock twice

deps/oblib/src/rpc/obmysql/ob_sql_nio.cpp

@@ -436,6 +436,7 @@ public:
   void shutdown() { ::shutdown(fd_, SHUT_RD); }
   int set_ssl_enabled();
   SSL* get_ssl_st();
+  int write_handshake_packet(const char* buf, int64_t sz);
 public:
   ObDLink dlink_;
   ObDLink all_list_link_;
@@ -478,6 +479,27 @@ SSL* ObSqlSock::get_ssl_st()
   return ob_fd_get_ssl_st(fd_);
 }
 
+int ObSqlSock::write_handshake_packet(const char* buf, int64_t sz) {
+  int ret = OB_SUCCESS;
+  int64_t pos = 0;
+  while(pos < sz && OB_SUCCESS == ret) {
+    int64_t wbytes = 0;
+    if ((wbytes = write(fd_, buf + pos, sz - pos)) >= 0) {
+      pos += wbytes;
+    } else if (EINTR == errno) {
+      //continue
+    } else {
+      //when send handshake packet, only process EINTR as normal, other errno
+      //will be treated as error
+      IGNORE_RETURN(set_error(EIO));
+      ret = OB_IO_ERROR;
+      LOG_WARN("write data error", K_(fd), K(errno));
+    }
+  }
+  last_write_time_ = ObTimeUtility::current_time();
+  return ret;
+}
+
 static struct epoll_event *__make_epoll_event(struct epoll_event *event, uint32_t event_flag, void* val) {
   event->events = event_flag;
   event->data.ptr = val;
@@ -1173,5 +1195,9 @@ void ObSqlNio::update_tcp_keepalive_params(int keepalive_enabled, uint32_t tcp_k
   }
 }
 
+int ObSqlNio::write_handshake_packet(void* sess, const char* buf, int64_t sz)
+{
+  return sess2sock(sess)->write_handshake_packet(buf, sz);
+}
 }; // end namespace obmysql
 }; // end namespace oceanbase

deps/oblib/src/rpc/obmysql/ob_sql_nio.h

@@ -58,6 +58,7 @@ public:
     return ATOMIC_FAA(&dispatch_idx_, 1) % get_thread_count();
   }
   void update_tcp_keepalive_params(int keepalive_enabled, uint32_t tcp_keepidle, uint32_t tcp_keepintvl, uint32_t tcp_keepcnt);
+  int write_handshake_packet(void* sess, const char* buf, int64_t sz);
 private:
   void run(int64_t idx);
 private:

deps/oblib/src/rpc/obmysql/ob_sql_sock_session.cpp

@@ -172,5 +172,10 @@ SSL* ObSqlSockSession::get_ssl_st()
   return nio_->get_ssl_st((void *)this);
 }
 
+int ObSqlSockSession::write_hanshake_packet(const char *buf, int64_t sz)
+{
+  return nio_->write_handshake_packet((void *)this, buf, sz);
+}
+
 }; // end namespace obmysql
 }; // end namespace oceanbase

deps/oblib/src/rpc/obmysql/ob_sql_sock_session.h

@@ -62,6 +62,7 @@ public:
   int set_ssl_enabled();
   SSL* get_ssl_st();
   bool is_inited() const { return is_inited_; }
+  int write_hanshake_packet(const char *buf, int64_t sz);
   ObSqlNio* nio_;
   ObISMConnectionCallback& sm_conn_cb_;
   rpc::ObRequest sql_req_;

src/observer/mysql/obsm_conn_callback.cpp

@@ -65,7 +65,7 @@ static int send_handshake(ObSqlSockSession& sess, const OMPKHandshake &hsp)
   } else if (OB_UNLIKELY(pkt_count <= 0)) {
     ret = OB_ERR_UNEXPECTED;
     LOG_WARN("invalid pkt count", K(pkt_count), K(ret));
-  } else if (OB_FAIL(sess.write_data(buf, pos))) {
+  } else if (OB_FAIL(sess.write_hanshake_packet(buf, pos))) {
     LOG_WARN("write handshake packet data fail", K(ret));
   }