xcb_sync_query_fence(3)

✨ xcb_sync_query_fence ✨

okay bestie, welcome to xcb_sync_query_fence from the XCB Requests corner of the X world 💖 this one lives in the libxcb manual, and we're gonna read it together like it's a group chat thread. no skimming, no skipping, we're doing the whole thing 🫶

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🌸 NAME 🌸

xcb_sync_query_fence — and that's it. fr fr, the description line is literally empty in the original. she's mysterious. she's giving main character energy with no caption 💅

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🎀 SYNOPSIS 🎀

first thing you need, always:

#include <xcb/sync.h>

💫 Request function 💫

xcb_sync_query_fence_cookie_t
       xcb_sync_query_fence(xcb_connection_t *conn,
       xcb_sync_fence_t fence);

💫 Reply datastructure 💫

typedef struct xcb_sync_query_fence_reply_t {
    uint8_t  response_type;
    uint8_t  pad0;
    uint16_t sequence;
    uint32_t length;
    uint8_t  triggered;
    uint8_t  pad1[23];
} xcb_sync_query_fence_reply_t;

💫 Reply function 💫

xcb_sync_query_fence_reply_t
       *xcb_sync_query_fence_reply(xcb_connection_t *conn,
       xcb_sync_query_fence_cookie_t cookie, xcb_generic_error_t **e);

so you fire off the request, you get a cookie back, and then you trade that cookie in with the reply function. iconic two-step. periodt ✨

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🦋 REQUEST ARGUMENTS 🦋

• conn — the XCB connection to X11. your lil lifeline to the server, she's everything 💜
• fence — TODO: NOT YET DOCUMENTED. yeah. the docs really said "we'll get to it" 😭 no cap, that's what it says.

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🌈 REPLY FIELDS 🌈

• response_type — the type of this reply, which in this case is XCB_SYNC_QUERY_FENCE. this field also shows up in the xcb_generic_reply_t, and it's literally how you tell your replies apart from each other, so don't sleep on it 👑
• sequence — the sequence number of the last request that got processed by the X11 server. the receipts, basically 🧾
• length — how long the reply is, in words. and yes bestie, a word here is 4 bytes. that's just the rules 💅
• triggered — TODO: NOT YET DOCUMENTED. another one. she said "mystery" and meant it 🙈

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💀 DESCRIPTION 💀

there is genuinely nothing here. the DESCRIPTION section is empty in the original. not a single word. it's giving silence, it's giving "read the rest and figure it out" 😭 we move.

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⭐ RETURN VALUE ⭐

you get back an xcb_sync_query_fence_cookie_t 🍪 and here's the important bit: errors have to be handled when you call the reply function, xcb_sync_query_fence_reply.

but if you'd rather handle your errors in the event loop instead, use xcb_sync_query_fence_unchecked. see xcb-requests(3) for the deets on that whole situation 🔥

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🔥 ERRORS 🔥

this request does never generate any errors. not one. zero. she's a good girl, she behaves 💖

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🌸 SEE ALSO 🌸

nothing listed. the SEE ALSO section is empty, so there's nobody to introduce her to 🥲

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🫶 AUTHOR 🫶

Generated from sync.xml. Contact xcb@lists.freedesktop.org for corrections and improvements — they literally put the address right there so you can slide into their inbox with fixes, and honestly? slay that they're open to it 💌

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okay that's the whole page, bestie, you ate it up 🌟 and a cute lil sign-off for the very end: this was X Version 11, libxcb 1.17.0, page xcb_sync_query_fence(3) — go forth and query those fences, mwah 💅✨🎀