sergensio_b_alloc.3(3)

✨ sergensio_b_alloc — the blocking edition 💅

okay bestie, so this page is about the sergensio_b_alloc.3 family of functions from the Library Functions Manual — literally the whole blocking-control-for-serial-parameters-on-a-sergensio situation. buckle up 🎀

---

🌸 NAME 🌸

sergensio_b_alloc, sergensio_b_free, sergensio_baud_b, sergensio_datasize_b, sergensio_parity_b, sergensio_stopbits_b, sergensio_flowcontrol_b, sergensio_iflowcontrol_b, sergensio_sbreak_b, sergensio_dtr_b, sergensio_rts_b — blocking control for serial parameters on a sergensio 🦋

---

✨ SYNOPSIS ✨

#include <gensio/sergensio.h>

int sergensio_b_alloc(struct sergensio *sio, struct gensio_os_funcs *o,
                    struct sergensio_b **new_sbio);

void sergensio_b_free(struct sergensio_b *sbio);

int sergensio_baud_b(struct sergensio_b *sbio, unsigned int *baud);

int sergensio_datasize_b(struct sergensio_b *sbio,
                    unsigned int *datasize);

int sergensio_parity_b(struct sergensio_b *sbio, unsigned int *parity);

int sergensio_stopbits_b(struct sergensio_b *sbio,
                    unsigned int *stopbits);

int sergensio_flowcontrol_b(struct sergensio_b *sbio,
                    unsigned int *flowcontrol);

int sergensio_iflowcontrol_b(struct sergensio_b *sbio,
                    unsigned int *iflowcontrol);

int sergensio_sbreak_b(struct sergensio_b *sbio, unsigned int *breakv);

int sergensio_dtr_b(struct sergensio_b *sbio, unsigned int *dtr);

int sergensio_rts_b(struct sergensio_b *sbio, unsigned int *rts);

int sergensio_cts_b(struct sergensio_b *sbio, unsigned int *cts);

int sergensio_dcd_dsr_b(struct sergensio_b *sbio, unsigned int
*dcd_dsr);

int sergensio_ri_b(struct sergensio_b *sbio, unsigned int *ri);

---

💖 DESCRIPTION 💖

so these are the glow-up versions of the non-blocking functions (the ones without the _b), except these ones block and wait for the results to come back. no "check back later", no "idk yet" — they wait. ⏳

⚠️ and listen, like all synchronous I/O, this comes with deadlock potential. deadlock is not cute. use these carefully, bestie, fr fr. 💀

to actually use these, you gotta first allocate a sergensio blocking data structure with sergensio_b_alloc so you can hand it to all the other functions. 🫶

okay and this is important: that allocated value can only be used for one operation at a time. one. singular. no sharing. 🙈 and when you're done with it, you must free it with sergensio_b_free. don't leave it hanging, that's rude. 🎀

with these functions, you pass a pointer to the value you want to set. here's the tea ☕ — if the pointed-to value is zero, the value is not set, it's just fetched. and if the function returns without an error, the actual current value gets returned in the passed-in pointer's destination. so you always walk away knowing the real value. slay. ✨

also lowkey important: these do not require gensio_set_sync to work, and they may be intermixed with non-blocking operations. mix and match, it's giving flexible. 🌈

for the details on the values and what they actually mean, go look at the various non-blocking functions — they've got the lore. 📚

---

🔥 RETURN VALUES 🔥

0 on success, or a gensio error on failure. that's it, that's the vibe check. ⭐

---

👑 SEE ALSO 👑

• sergensio(5)
• sergensio_baud(3)
• sergensio_datasize(3)
• sergensio_parity(3)
• sergensio_stopbits(3)
• sergensio_flowcontrol(3)
• sergensio_iflowonctrol(3)
• sergensio_sbreak(3)
• sergensio_dtr(3)
• sergensio_rts(3)

(and yes, it really does say sergensio_iflowonctrol(3) up there — we don't fix typos in this house, we preserve them. 💅 iykyk.)

---

💜 AUTHOR 💜

Corey Minyard <minyard@acm.org> — the icon, the moment, the main character. 👑

---

and that's the whole page bestie!! this one's from way back on 20 Jul 2020, source/version sergensio_b_alloc.3(3), and honestly it ate. go forth and block responsibly. mwah 💋✨