message: Move to stack and warning free.
diff: @@ -187,7 +187,7 @@ static PHP_METHOD(swoole_postgresql_coro, connect)
  if (pgsql==NULL || PQstatus(pgsql)==CONNECTION_BAD)
  {
  - swWarn("Unable to connect to PostgreSQL server: [%s]",pgsql);
  + swWarn("Unable to connect to PostgreSQL server: [%s]", PQhost(pgsql));
  if (pgsql)
  {
  PQfinish(pgsql);
  @@ -221,14 +221,14 @@ static PHP_METHOD(swoole_postgresql_coro, connect)
  static void swoole_pgsql_coro_onTimeout(swTimer *timer, swTimer_node *tnode)
  {
  - zval *result;
  + zval _result;
  + zval *result = &_result;
  zval *retval = NULL;
  PGconn *pgsql;
  php_context *ctx = tnode->data;
  char *feedback;
  char *err_msg;
  - SW_ALLOC_INIT_ZVAL(result);
  ZVAL_BOOL(result, 0);
  zval _zobject = ctx->coro_params;
  @@ -267,7 +267,7 @@ static void swoole_pgsql_coro_onTimeout(swTimer *timer, swTimer_node *tnode)
  {
  sw_zval_ptr_dtor(&retval);
  }
  - sw_zval_free(result);
  + zval_ptr_dtor(result);
  }
  static int swoole_pgsql_coro_onWrite(swReactor *reactor, swEvent *event)
  @@ -1039,18 +1039,19 @@ static void _free_result(zend_resource *rsrc)
  static int swoole_pgsql_coro_onError(swReactor *reactor, swEvent *event)
  {
  + zval _result;
  + zval *result = &_result;
  pg_object *pg_object = (event->socket->object);
  - zval *retval = NULL, *result;
  + zval *retval = NULL;
  zval *zobject = pg_object->object;
  swoole_postgresql_coro_close(pg_object);
  - SW_ALLOC_INIT_ZVAL(result);
  ZVAL_BOOL(result, 0);
  php_context *sw_current_context = swoole_get_property(zobject, 0);
  int ret = coro_resume(sw_current_context, result, &retval);
  - sw_zval_free(result);
  + zval_ptr_dtor(result);
  if (ret == CORO_END && retval)
  {
  