This function is useful for dynamic language garbage collectors. Frequently
a GC cycle may run before you want to block wainting for a reply.
This function is also marginally useful for libxcb apps that issue
speculative requests (eg. xlsclients).
Reviewed-by: Jamey Sharp <jamey@minilop.net>
Tested-by: Eamon Walsh <efw@eamonwalsh.com>
Signed-off-by: Peter Harris <pharris@opentext.com>