NNG_CTX_RECV(3)

💖 NNG_CTX_RECV 💖

okay bestie, welcome to the nng_ctx_recv page from the NNG Reference Manual 📖 — this is the one where you get messages through a context and everything happens asynchronously, which is a fancy way of saying "don't wait around, girl, the callback will text you back" 💅

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✨ NAME ✨

nng_ctx_recv — receive a message using a context, asynchronously 🦋

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✨ SYNOPSIS ✨

#include <nng/nng.h>

void nng_ctx_recv(nng_ctx ctx, nng_aio *aio);

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✨ DESCRIPTION ✨

So like. nng_ctx_recv() receives a message using the context ctx, and it does it asynchronously — no blocking, no waiting, main character energy only 👑

When a message gets successfully received by the context, it's stashed into the aio by an internal call that's equivalent to nng_aio_set_msg(), and then the completion callback on the aio runs. In that happy little case, nng_aio_result() returns zero. And it's literally your job — the callback function's job — to go grab that message and dispose of it properly. That's the whole assignment. 🎀

IMPORTANT, fr fr 💀 Failing to accept and dispose of messages in this case can lead to memory leaks. Not cute. Not slay. Just leak. So please actually take the message, bestie 😭

If for some reason the async receive can't complete successfully — and yes, that includes it being canceled or timing out — the callback still runs, but nng_aio_result() will be non-zero. She still shows up to the party, she's just bringing bad news 🙈

Note 🔍 What "receiving a message" even means varies from protocol to protocol, so please go read the protocol documentation too. It's giving "context matters." Examined. Encouraged. 🌸

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✨ RETURN VALUES ✨

None. Because the operation completes asynchronously — nothing to return, it's all vibes and callbacks ✨

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✨ ERRORS ✨

• NNG_ECANCELED — bestie the operation was aborted 💀
• NNG_ECLOSED — the context ctx is not open. Door's shut, girl 🚪
• NNG_ENOMEM — not enough memory available. The RAM said no 😭
• NNG_ENOTSUP — the protocol for context ctx does not support receiving. Not every protocol wants to catch these messages 🙈
• NNG_ESTATE — the context ctx cannot receive data in this state. Wrong era, wrong state, wrong vibe check 🦋
• NNG_ETIMEDOUT — the receive timeout expired. She waited, she left ⌛

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✨ SEE ALSO ✨

nng_aio_get_msg(3), nng_aio_set_msg(3), nng_msg_alloc(3), nng_strerror(3), nng_aio(5), nng_ctx(5), nng_msg(5), nng(7)

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okay that's the whole page, you ate that 🍓 go forth and receive your messages responsibly, dispose of them, and do not leak memory, that's the bare minimum 🫶

signing off with the tea ☕: this one's from the NNG Reference Manual, dated 2026-06-30, and yeah — that's the same day as the page header said. periodt. 💜