qthread_readFE(3)

💖 qthread_readFE — from the libqthread girlies 💖

okay so bestie, this is a page from libqthread, and today's main character is qthread_readFE(3). she waits for your source to be full, then copies it and empties it. it's giving ✨ the classic read-and-empty ✨ and honestly? iconic.

✨ NAME ✨

qthread_readFE — waits for the source to be full, then copies it and empties it 🫶

🌸 SYNOPSIS 🌸

#include <qthread.h>

int
qthread_readFE (aligned_t *dest, const aligned_t *src);

🦋 DESCRIPTION 🦋

so basically, this function waits for memory to become full, and then it empties it. the way it works: when the memory becomes full, only one thread that's blocked like this gets awoken. no cap, just one. 🎀

data gets read from src and stored in dest.

the semantics of readFE are, in order, periodt:

1. src's FEB state must be "full"
2. data is copied from src to dest
3. src's FEB state gets changed from "full" to "empty"

💀 WARNING 💀

this one, and literally all the other FEB-related functions, currently operate exclusively on aligned data. this is to simulate the behavior of the XMT as closely as possible. the library requires 4- or 8-byte alignment, depending on whether you compiled in 32-bit or 64-bit mode. pls don't skip this part, she's serious 🙈

⭐ RETURN VALUE ⭐

on success: the memory address src is marked empty, the memory address dest is filled with the contents of src, and 0 is returned. slay. 💅

on error: a non-zero error code is returned. 😭

🌈 ERRORS 🌈

• ENOMEM — not enough memory could be allocated for bookkeeping structures. sad girl hours, honestly.

👑 SEE ALSO 👑

• qthread_empty(3)
• qthread_fill(3)
• qthread_writeEF(3)
• qthread_writeF(3)
• qthread_readFF(3)
• qthread_lock(3)
• qthread_unlock(3)

okay that's the whole page, bestie, you ate that. this was brought to you by libqthread, dated APRIL 2011 — yeah she's a vintage queen and she still runs the group chat. mwah 💋💖