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| author | Garrett D'Amore <garrett@damore.org> | 2024-12-31 17:44:57 -0800 |
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| committer | Garrett D'Amore <garrett@damore.org> | 2024-12-31 17:47:54 -0800 |
| commit | ecad76e6b96616d4b04a0af607830343427bf9fa (patch) | |
| tree | 2da414284c93775a6d099227d4db697e15a210b0 /docs/man/nng_recv.3.adoc | |
| parent | 38ae046fdfd2875855d5cae8722263c88e81067d (diff) | |
| download | nng-ecad76e6b96616d4b04a0af607830343427bf9fa.tar.gz nng-ecad76e6b96616d4b04a0af607830343427bf9fa.tar.bz2 nng-ecad76e6b96616d4b04a0af607830343427bf9fa.zip | |
docs: convert socket receive docs
Diffstat (limited to 'docs/man/nng_recv.3.adoc')
| -rw-r--r-- | docs/man/nng_recv.3.adoc | 91 |
1 files changed, 0 insertions, 91 deletions
diff --git a/docs/man/nng_recv.3.adoc b/docs/man/nng_recv.3.adoc deleted file mode 100644 index ef1f2756..00000000 --- a/docs/man/nng_recv.3.adoc +++ /dev/null @@ -1,91 +0,0 @@ -= nng_recv(3) -// -// Copyright 2018 Staysail Systems, Inc. <info@staysail.tech> -// Copyright 2018 Capitar IT Group BV <info@capitar.com> -// -// This document is supplied under the terms of the MIT License, a -// copy of which should be located in the distribution where this -// file was obtained (LICENSE.txt). A copy of the license may also be -// found online at https://opensource.org/licenses/MIT. -// - -== NAME - -nng_recv - recv data - -== SYNOPSIS - -[source, c] ----- -#include <nng/nng.h> - -int nng_recv(nng_socket s, void *data, size_t *sizep, int flags); ----- - -== DESCRIPTION - -The `nng_recv()` receives a message. - -The _flags_ is a bit mask that may contain any of the following values: - -`NNG_FLAG_NONBLOCK`:: - The function returns immediately, even if no message is available. - Without this flag, the function will wait until a message is received - by the socket _s_, or any configured timer expires. - -`NNG_FLAG_ALLOC`:: - If this flag is present, then a ((zero-copy)) mode is used. - In this case the caller must set the value of _data_ to the location - of another pointer (of type `void *`), and the _sizep_ pointer must be set - to a location to receive the size of the message body. - The function will then allocate a message buffer - (as if by xref:nng_alloc.3.adoc[`nng_alloc()`]), fill it with - the message body, and store it at the address referenced by _data_, and update - the size referenced by _sizep_. - The caller is responsible for disposing of the received buffer either by - the xref:nng_free.3.adoc[`nng_free()`] function or passing the message (also - with the `NNG_FLAG_ALLOC` flag) in a call to xref:nng_send.3.adoc[`nng_send()`]. - -If the special flag `NNG_FLAG_ALLOC` (see above) is not specified, then the -caller must set _data_ to a buffer to receive the message body content, -and must store the size of that buffer at the location pointed to by _sizep_. -When the function returns, if it is successful, the size at _sizep_ will be -updated with the actual message body length copied into _data_. - -NOTE: The semantics of what receiving a message means vary from protocol to -protocol, so examination of the protocol documentation is encouraged. -(For example, with a xref:nng_req.7.adoc[_req_] socket a message may only be received -after a request has been sent, and a xref:nng_sub.7.adoc[_sub_] socket -may only receive messages corresponding to topics to which it has subscribed.) -Furthermore, some protocols may not support receiving data at all, such as -xref:nng_pub.7.adoc[_pub_]. - -TIP: The `NNG_FLAG_ALLOC` flag can be used to reduce data copies, thereby -increasing performance, particularly if the buffer is reused to send -a response using the same flag. - -== RETURN VALUES - -This function returns 0 on success, and non-zero otherwise. - -== ERRORS - -[horizontal] -`NNG_EAGAIN`:: The operation would block, but `NNG_FLAG_NONBLOCK` was specified. -`NNG_ECLOSED`:: The socket _s_ is not open. -`NNG_EINVAL`:: An invalid set of _flags_ was specified. -`NNG_EMSGSIZE`:: The received message did not fit in the size provided. -`NNG_ENOMEM`:: Insufficient memory is available. -`NNG_ENOTSUP`:: The protocol for socket _s_ does not support receiving. -`NNG_ESTATE`:: The socket _s_ cannot receive data in this state. -`NNG_ETIMEDOUT`:: The operation timed out. - -== SEE ALSO - -[.text-left] -xref:nng_alloc.3.adoc[nng_alloc(3)], -xref:nng_free.3.adoc[nng_free(3)], -xref:nng_recvmsg.3.adoc[nng_recvmsg(3)], -xref:nng_send.3.adoc[nng_send(3)], -xref:nng_strerror.3.adoc[nng_strerror(3)], -xref:nng.7.adoc[nng(7)] |
