qthread_lock/unlock(3)

💅 qthread_lock / qthread_unlock — the manual page, but make it cute

okay bestie, we're in section 3 of the libqthread manuals and today's episode is all about locking and unlocking an address. yes, an actual memory address. no, it's not that deep, but also it kind of is. 🫶

✨ NAME ✨

qthread_lock, qthread_unlock — lock or unlock an address 🔒🔓

🌸 SYNOPSIS 🌸

#include <qthread.h>

int
qthread_lock (aligned_t *addr);

int
qthread_unlock (aligned_t *addr);

🦋 DESCRIPTION 🦋

so these two little icons are here to implement FEB-like locking and unlocking, except — plot twist — they behave way more like a mutex. it's giving glow-up. 💖

they're atomic and they functional, fr fr, but lowkey they do not have the same semantics as full FEB locking/unlocking. the specific tea here: unlocking cannot block. that's the whole trade-off. 🎀

and because of that little limitation? they have lower overhead. less drama, less cost, iconic behaviour honestly. ✨

🔥 RETURN VALUE 🔥

when it works, the memory address addr gets marked locked or unlocked appropriately and you get back 0. 🫶

if you try to unlock an address that's already unlocked? bestie, that's fine, you get QTHREAD_SUCCESS back. no harm, no foul, no shame. 😌

on error, you get a non-zero error code. not zero. zero is the good one. remember that. 💀

💀 ERRORS 💀

• ENOMEM — not enough memory could be allocated for the bookkeeping structures. the vibes were immaculate but the RAM said no. 😭

👑 SEE ALSO 👑

go read these next, they're all in the group chat:

• qthread_empty(3)
• qthread_fill(3)
• qthread_writeEF(3)
• qthread_writeF(3)
• qthread_readFF(3)
• qthread_readFE(3)

remember bestie: these are atomic and they work, but they are not full FEB locking/unlocking semantics — unlocking can't block, and that's by design, not a bug. don't come for me. 💅

mwah, that's the whole page. this lil' beauty ships with libqthread and it's dated APRIL 2011 — vintage, honestly, and still slaying. 🌈💜🌸