diff --git a/clean.sh b/clean.sh
index 3d4ee533..9f74221f 100755
--- a/clean.sh
+++ b/clean.sh
@@ -1,3 +1,7 @@
 #! /bin/bash
 
 bazel clean --expunge
+
+# Delete xx.log or xx.bin on root directory of trpc-cpp project.
+find ./ -maxdepth 1 -name "*.log" -exec rm {} \;
+find ./ -maxdepth 1 -name "*.bin" -exec rm {} \;
diff --git a/trpc/runtime/iomodel/reactor/common/io_handler.h b/trpc/runtime/iomodel/reactor/common/io_handler.h
index 28875d0e..2e07e816 100644
--- a/trpc/runtime/iomodel/reactor/common/io_handler.h
+++ b/trpc/runtime/iomodel/reactor/common/io_handler.h
@@ -45,6 +45,9 @@ class IoHandler {
 
   /// @brief write data to the connection
   virtual int Writev(const iovec* iov, int iovcnt) = 0;
+
+  /// @brief Destroy IO handler.
+  virtual void Destroy() {}
 };
 
 }  // namespace trpc
diff --git a/trpc/runtime/iomodel/reactor/default/tcp_connection.cc b/trpc/runtime/iomodel/reactor/default/tcp_connection.cc
index 2e913e83..99f2868a 100644
--- a/trpc/runtime/iomodel/reactor/default/tcp_connection.cc
+++ b/trpc/runtime/iomodel/reactor/default/tcp_connection.cc
@@ -101,6 +101,7 @@ bool TcpConnection::DoConnect() {
                                                      << ", failed. error no: " << errno
                                                      << ", msg: " << strerror(errno));
 
+  GetIoHandler()->Destroy();
   socket_.Close();
   HandleClose(false);
 
@@ -353,6 +354,9 @@ void TcpConnection::HandleClose(bool destroy) {
   }
   io_msgs_.clear();
 
+  // Requirements: destroy IO-handler before close socket.
+  GetIoHandler()->Destroy();
+
   DisableReadWrite();
 
   handshake_status_ = IoHandler::HandshakeStatus::kFailed;
diff --git a/trpc/runtime/iomodel/reactor/fiber/fiber_tcp_connection.cc b/trpc/runtime/iomodel/reactor/fiber/fiber_tcp_connection.cc
index 555e463b..00ebde16 100644
--- a/trpc/runtime/iomodel/reactor/fiber/fiber_tcp_connection.cc
+++ b/trpc/runtime/iomodel/reactor/fiber/fiber_tcp_connection.cc
@@ -31,6 +31,10 @@ FiberTcpConnection::FiberTcpConnection(Reactor* reactor, const Socket& socket)
 }
 
 FiberTcpConnection::~FiberTcpConnection() {
+  // Requirements: destroy IO-handler before close socket.
+  GetIoHandler()->Destroy();
+  socket_.Close();
+
   TRPC_LOG_DEBUG("~FiberTcpConnection fd:" << socket_.GetFd() << ", conn_id:" << this->GetConnId());
   TRPC_ASSERT(!socket_.IsValid());
 }
@@ -77,6 +81,7 @@ bool FiberTcpConnection::DoConnect() {
                                                           << ", is_client:" << IsClient()
                                                           << ", conn_id: " << this->GetConnId() << ", failed.");
 
+  GetIoHandler()->Destroy();
   socket_.Close();
 
   return false;
@@ -361,7 +366,7 @@ void FiberTcpConnection::OnCleanup(CleanupReason reason) {
 
   writing_buffers_.Stop();
 
-  socket_.Close();
+  // For multi-threads-safety, move "socket_.Close()" to ~FiberTcpConnection();
 }
 
 IoHandler::HandshakeStatus FiberTcpConnection::DoHandshake(bool from_on_readable) {
diff --git a/trpc/transport/common/ssl/ssl.cc b/trpc/transport/common/ssl/ssl.cc
index 495798c5..1f62850f 100644
--- a/trpc/transport/common/ssl/ssl.cc
+++ b/trpc/transport/common/ssl/ssl.cc
@@ -679,6 +679,7 @@ Ssl::~Ssl() {
   if (ssl_) {
     SSL_shutdown(ssl_);
     SSL_free(ssl_);
+    ssl_ = nullptr;
   }
 }
 
diff --git a/trpc/transport/common/ssl_io_handler.cc b/trpc/transport/common/ssl_io_handler.cc
index a38d79f2..115e3040 100644
--- a/trpc/transport/common/ssl_io_handler.cc
+++ b/trpc/transport/common/ssl_io_handler.cc
@@ -76,6 +76,14 @@ int SslIoHandler::Writev(const struct iovec* iov, int iovcnt) {
   return n;
 }
 
+void SslIoHandler::Destroy() {
+  if (ssl_) {
+    ssl_->Shutdown();
+    ssl_ = nullptr;
+    handshaked_ = false;
+  }
+}
+
 }  // namespace trpc::ssl
 
 #endif
diff --git a/trpc/transport/common/ssl_io_handler.h b/trpc/transport/common/ssl_io_handler.h
index 14d6a0d2..76c57be9 100644
--- a/trpc/transport/common/ssl_io_handler.h
+++ b/trpc/transport/common/ssl_io_handler.h
@@ -35,6 +35,8 @@ class SslIoHandler : public IoHandler {
 
   int Writev(const struct iovec* iov, int iovcnt) override;
 
+  void Destroy() override;
+
  private:
   Connection* conn_{nullptr};
   SslPtr ssl_{nullptr};