fix(query): fix pthread_create memleak in shell engine

TD-17791

tools/shell/inc/shellInt.h

@@ -95,6 +95,7 @@ typedef struct {
   TAOS*           conn;
   TdThread        pid;
   tsem_t          cancelSem;
+  bool            exit;
 #ifdef WEBSOCKET
   WS_TAOS*        ws_conn;
   bool		      stop_query;

tools/shell/src/shellEngine.c

@@ -948,6 +948,10 @@ void shellCleanup(void *arg) { taosResetTerminalMode(); }
 void *shellCancelHandler(void *arg) {
   setThreadName("shellCancelHandler");
   while (1) {
+    if (shell.exit == true) {
+      break;
+    }
+
     if (tsem_wait(&shell.cancelSem) != 0) {
       taosMsleep(10);
       continue;
@@ -1079,7 +1083,12 @@ int32_t shellExecute() {
     taosThreadCreate(&shell.pid, NULL, shellThreadLoop, NULL);
     taosThreadJoin(shell.pid, NULL);
     taosThreadClear(&shell.pid);
+    if (shell.exit) {
+      tsem_post(&shell.cancelSem);
+      break;
     }
+  }
+  taosThreadJoin(spid, NULL);
 
   shellCleanupHistory();
   return 0;

tools/shell/src/shellUtil.c

@@ -157,6 +157,6 @@ void shellExit() {
     taos_close(shell.conn);
     shell.conn = NULL;
   }
+  shell.exit = true;
   taos_cleanup();
-  exit(EXIT_FAILURE);
 }