diff --git a/source/os/src/osTimer.c b/source/os/src/osTimer.c
index 5a57007d17..b8eb54e10e 100644
--- a/source/os/src/osTimer.c
+++ b/source/os/src/osTimer.c
@@ -114,27 +114,28 @@ static void         *taosProcessAlarmSignal(void *tharg) {
 
   taosThreadCleanupPush(taosDeleteTimer, &timerId);
 
-  struct itimerspec ts;
-  ts.it_value.tv_sec = 0;
-  ts.it_value.tv_nsec = 1000000 * MSECONDS_PER_TICK;
-  ts.it_interval.tv_sec = 0;
-  ts.it_interval.tv_nsec = 1000000 * MSECONDS_PER_TICK;
+  do {
+    struct itimerspec ts;
+    ts.it_value.tv_sec = 0;
+    ts.it_value.tv_nsec = 1000000 * MSECONDS_PER_TICK;
+    ts.it_interval.tv_sec = 0;
+    ts.it_interval.tv_nsec = 1000000 * MSECONDS_PER_TICK;
 
-  if (timer_settime(timerId, 0, &ts, NULL)) {
-            // printf("Failed to init timer");
-    return NULL;
-  }
-
-  int signo;
-  while (!stopTimer) {
-            if (sigwait(&sigset, &signo)) {
-              // printf("Failed to wait signal: number %d", signo);
-      continue;
+    if (timer_settime(timerId, 0, &ts, NULL)) {
+      // printf("Failed to init timer");
+      break;
     }
-            /* //printf("Signal handling: number %d ......\n", signo); */
 
-            callback(0);
-  }
+    int signo;
+    while (!stopTimer) {
+      if (sigwait(&sigset, &signo)) {
+        // printf("Failed to wait signal: number %d", signo);
+        continue;
+      }
+      /* //printf("Signal handling: number %d ......\n", signo); */
+      callback(0);
+    }
+  } while (0);
 
   taosThreadCleanupPop(1);
 
diff --git a/tools/shell/src/shellEngine.c b/tools/shell/src/shellEngine.c
index 655fef383e..05183a036c 100644
--- a/tools/shell/src/shellEngine.c
+++ b/tools/shell/src/shellEngine.c
@@ -1048,26 +1048,28 @@ void *shellThreadLoop(void *arg) {
   taosGetOldTerminalMode();
   taosThreadCleanupPush(shellCleanup, NULL);
 
-  char *command = taosMemoryMalloc(SHELL_MAX_COMMAND_SIZE);
-  if (command == NULL) {
-    printf("failed to malloc command\r\n");
-    return NULL;
-  }
-
   do {
-    memset(command, 0, SHELL_MAX_COMMAND_SIZE);
-    taosSetTerminalMode();
-
-    if (shellReadCommand(command) != 0) {
+    char *command = taosMemoryMalloc(SHELL_MAX_COMMAND_SIZE);
+    if (command == NULL) {
+      printf("failed to malloc command\r\n");
       break;
     }
 
-    taosResetTerminalMode();
-  } while (shellRunCommand(command, true) == 0);
+    do {
+      memset(command, 0, SHELL_MAX_COMMAND_SIZE);
+      taosSetTerminalMode();
 
-  taosMemoryFreeClear(command);
-  shellWriteHistory();
-  shellExit();
+      if (shellReadCommand(command) != 0) {
+        break;
+      }
+
+      taosResetTerminalMode();
+    } while (shellRunCommand(command, true) == 0);
+
+    taosMemoryFreeClear(command);
+    shellWriteHistory();
+    shellExit();
+  } while (0);
 
   taosThreadCleanupPop(1);
   return NULL;