Constant xcb::ffi::xproto::XCB_ALLOW_ASYNC_BOTH

pub const XCB_ALLOW_ASYNC_BOTH: xcb_allow_t

For AsyncBoth, if the pointer and the keyboard are frozen by the client, event processing for both devices continues normally. If a device is frozen twice by the client on behalf of two separate grabs, AsyncBoth thaws for both. AsyncBoth has no effect unless both pointer and keyboard are frozen by the client.