xcb_dri2_wait_sbc(3)

✨ xcb_dri2_wait_sbc ✨

okay bestie, pull up a chair 🫶 because today we're reading xcb_dri2_wait_sbc(3), straight out of the XCB Requests collection. it's a lil XCB request from the dri2 era, and honestly? the docs are giving mysterious. we're gonna walk through every single line together, no skipping, periodt. 💖

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🌸 NAME 🌸

xcb_dri2_wait_sbc — and then… nothing. literally nothing. the description is blank. the manpage just trails off into the void like my attention span during a 3-hour lecture. 😭 that's not me being lazy, that's just what's actually written. iconic honestly.

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🎀 SYNOPSIS 🎀

first thing you gotta do is pull in the header:

#include <xcb/dri2.h>

Request function

here's the actual request, in all its glory:

xcb_dri2_wait_sbc_cookie_t xcb_dri2_wait_sbc(xcb_connection_t *conn,
       xcb_drawable_t drawable, uint32_t target_sbc_hi,
       uint32_t target_sbc_lo);

Reply datastructure

and here's the struct that comes back at you:

typedef struct xcb_dri2_wait_sbc_reply_t {
    uint8_t  response_type;
    uint8_t  pad0;
    uint16_t sequence;
    uint32_t length;
    uint32_t ust_hi;
    uint32_t ust_lo;
    uint32_t msc_hi;
    uint32_t msc_lo;
    uint32_t sbc_hi;
    uint32_t sbc_lo;
} xcb_dri2_wait_sbc_reply_t;

Reply function

and the function that actually hands you that struct:

xcb_dri2_wait_sbc_reply_t
       *xcb_dri2_wait_sbc_reply(xcb_connection_t *conn,
       xcb_dri2_wait_sbc_cookie_t cookie, xcb_generic_error_t **e);

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🦋 REQUEST ARGUMENTS 🦋

okay so here's what you're passing in:

• conn — your XCB connection to X11. the whole reason we're here, the main character of every XCB function tbh. 👑
• drawable — TODO: NOT YET DOCUMENTED. yeah. they said "we'll get to it" and then never did. 💀
• target_sbc_hi — TODO: NOT YET DOCUMENTED. same vibe. 🫠
• target_sbc_lo — TODO: NOT YET DOCUMENTED. the trilogy of unfinished business, fr fr.

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💜 REPLY FIELDS 💜

here's everything that comes back in the reply struct:

• response_type — the type of this reply, and for this one it's XCB_DRI2_WAIT_SBC. this field also lives in the xcb_generic_reply_t, so you can use it to tell your replies apart from each other. it's like a name tag at a party but for structs. 🎀
• sequence — the sequence number of the last request processed by the X11 server. tracking numbers but make it ✨server✨.
• length — the length of the reply, in words. and heads up, a word here is 4 bytes. not a dictionary word. computer word. iykyk. 🧠
• ust_hi — TODO: NOT YET DOCUMENTED.
• ust_lo — TODO: NOT YET DOCUMENTED.
• msc_hi — TODO: NOT YET DOCUMENTED.
• msc_lo — TODO: NOT YET DOCUMENTED.
• sbc_hi — TODO: NOT YET DOCUMENTED.
• sbc_lo — TODO: NOT YET DOCUMENTED.

so many hi/lo pairs and so little documentation. it's giving unsolved mystery podcast. 🙈

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🌈 DESCRIPTION 🌈

literally nothing here. the DESCRIPTION section is empty. bestie the void is voiding. 😭

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⭐ RETURN VALUE ⭐

it returns an xcb_dri2_wait_sbc_cookie_t. 🍪 and listen — errors have to be handled when you call the reply function xcb_dri2_wait_sbc_reply. so you don't get to just ignore them, you gotta deal with them at reply time.

but wait, there's a plot twist ✨ — if you'd rather handle errors in the event loop instead, use xcb_dri2_wait_sbc_unchecked. see xcb-requests(3) for all the deets on how that works.

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💀 ERRORS 💀

good news bestie: this request never generates any errors. not a single one. it's the low-drama friend of the group chat. no cap. 🕊️

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🔥 SEE ALSO 🔥

this section is empty. no cross-references listed. it's giving "i have no friends" but in manpage form. 😭 (not true tho, xcb-requests(3) got mentioned up in RETURN VALUE, so go read that one 💖)

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👑 AUTHOR 👑

generated from dri2.xml. and if you spot something wrong or wanna make it better, contact xcb@lists.freedesktop.org for corrections and improvements. they're literally asking for feedback, so if you find something, say something. 🫶

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and that's the whole page, bestie! 💅 this one came to you from X Version 11 and libxcb 1.17.0, and the manual page itself is xcb_dri2_wait_sbc(3). now go forth and handle those errors in the event loop, mwah. 🌸✨🎀