delim $$
No round trip is forced to the server; unlike most X calls that return a value, ggllXXGGeettCCoonntteexxttIIDDEEXXTT does not flush any pending events.
ggllXXGGeettCCoonntteexxttIIDDEEXXTT is part of the EEXXTT__iimmppoorrtt__ccoonntteexxtt extension, not part of the core GLX command set. If GGLLXX__EEXXTT__iimmppoorrtt__ccoonntteexxtt is included in the string returned by ggllXXQQuueerryyEExxtteennssiioonnssSSttrriinngg, when called with argument GGLLXX__EEXXTTEENNSSIIOONNSS, extension EEXXTT__iimmppoorrtt__ccoonntteexxtt is supported.