rpma_cq_get_fd(3)

💖 rpma_cq_get_fd(3) 💖

okay bestie, welcome to the RPMA Programmer's Manual ✨ this one's all about grabbing the completion queue's file descriptor, and honestly? it's giving main character energy 🎀

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✨ NAME ✨

rpma_cq_get_fd — get the completion queue's file descriptor 🦋

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🌸 SYNOPSIS 🌸

#include <librpma.h>

struct rpma_cq;
int rpma_cq_get_fd(const struct rpma_cq *cq, int *fd);

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💅 DESCRIPTION 💅

so rpma_cq_get_fd() grabs you the file descriptor of the completion queue — aka the CQ, bestie, we abbreviate around here 💜

when the next completion in the CQ is ready to be consumed by rpma_cq_get_wc(3), the notification gets delivered to you through that file descriptor. that's the whole vibe. that's the pipeline. 🔥

the default mode of the file descriptor is blocking, but like… you can switch it to non-blocking mode using fcntl(2). your call, your rules 💅

now, the CQ in question is one of these three cuties — no more, no less:

• the connection's main CQ — peep rpma_conn_get_cq(3)
• the receive CQ — peep rpma_conn_get_rcq(3)
• the CQ of shared RQ — peep rpma_srq_get_rcq()

pick your fighter, details are in those pages 🫶

⚠️ note, and this is lowkey important: after you spot the notification using the file descriptor you were given, you do not have to call rpma_cq_wait(3) before consuming the completion. no cap. BUT — and it's a big but — it may cause the next call to rpma_cq_wait(3) to notify you of a completion you already consumed. awkward. 😭 consider yourself warned, bestie.

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🎀 RETURN VALUE 🎀

rpma_cq_get_fd() returns 0 on success, or a negative error code on failure. and listen — on failure it does not set the *fd value. like, at all. don't go reading it. 🙈

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🌈 ERRORS 🌈

rpma_cq_get_fd() can fail with the following error:

• RPMA_E_INVAL — cq or fd is NULL 💀

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👑 SEE ALSO 👑

fcntl(2), rpma_conn_get_cq(3), rpma_conn_get_rcq(3), rpma_srq_get_rcq(3), rpma_cq_wait(3), rpma_cq_get_wc(3), librpma(7) and https://pmem.io/rpma/

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okay that's the whole page, you absolutely ate it bestie 🍓 this was the RPMA manual page, dropped on 01 April 2024 ⭐ go get those completions, periodt 💖✨🧚