fix: ctrl+c problem in cli mode.

src/observer/common/rc.h

@@ -28,6 +28,7 @@ See the Mulan PSL v2 for more details. */
   DEFINE_RC(NOMEM)                          \
   DEFINE_RC(NOTFOUND)                       \
   DEFINE_RC(EMPTY)                          \
+  DEFINE_RC(EMPTY_CMD)                      \
   DEFINE_RC(BUFFERPOOL_OPEN)                \
   DEFINE_RC(BUFFERPOOL_NOBUF)               \
   DEFINE_RC(BUFFERPOOL_INVALID_PAGE_NUM)    \

src/observer/net/cli_communicator.cpp

@@ -86,19 +86,6 @@ bool is_exit_command(const char *cmd) {
          0 == strncasecmp("\\q", cmd, 2) ;
 }
 
-char *read_command()
-{
-  const char *prompt_str = "miniob > ";
-  char *input_command = nullptr;
-  for (input_command = my_readline(prompt_str); 
-        common::is_blank(input_command); 
-        input_command = my_readline(prompt_str)) {
-    free(input_command);
-    input_command = nullptr;
-  }
-  return input_command;
-}
-
 RC CliCommunicator::init(int fd, Session *session, const std::string &addr)
 {
   RC rc = PlainCommunicator::init(fd, session, addr);
@@ -126,7 +113,12 @@ RC CliCommunicator::init(int fd, Session *session, const std::string &addr)
 RC CliCommunicator::read_event(SessionEvent *&event)
 {
   event = nullptr;
-  char *command = read_command();
+  char *command = my_readline("miniob > ");
+  if (common::is_blank(command)) {
+    free(command);
+    event = nullptr;
+    return RC::EMPTY_CMD;
+  }
 
   if (is_exit_command(command)) {
     free(command);

src/observer/net/server.cpp

@@ -323,11 +323,14 @@ int Server::start_stdin_server()
     SessionEvent *event = nullptr;
     rc = communicator->read_event(event);
     if (OB_FAIL(rc)) {
+      if (rc == RC::EMPTY_CMD) {
+        continue;
+      }
       LOG_WARN("failed to read event. rc=%s", strrc(rc));
       return -1;
     }
 
-    if (event == nullptr) {
+    if (event == nullptr || !started_) {
       break;
     }