From b7736d01265c6d6ce4fcc6822ea3cd5e23fb7094 Mon Sep 17 00:00:00 2001 From: Garrett D'Amore Date: Tue, 31 Dec 2024 16:31:04 -0800 Subject: doc: document socket send API, including an example --- docs/man/nng_send.3.adoc | 100 ------------------------------------------- docs/man/nng_send_aio.3.adoc | 91 --------------------------------------- docs/man/nng_sendmsg.3.adoc | 94 ---------------------------------------- 3 files changed, 285 deletions(-) delete mode 100644 docs/man/nng_send.3.adoc delete mode 100644 docs/man/nng_send_aio.3.adoc delete mode 100644 docs/man/nng_sendmsg.3.adoc (limited to 'docs/man') diff --git a/docs/man/nng_send.3.adoc b/docs/man/nng_send.3.adoc deleted file mode 100644 index 7037f547..00000000 --- a/docs/man/nng_send.3.adoc +++ /dev/null @@ -1,100 +0,0 @@ -= nng_send(3) -// -// Copyright 2018 Staysail Systems, Inc. -// Copyright 2018 Capitar IT Group BV -// -// 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_send - send data - -== SYNOPSIS - -[source, c] ----- -#include - -int nng_send(nng_socket s, void *data, size_t size, int flags); ----- - -== DESCRIPTION - -The `nng_send()` function sends a message containing the _data_ of -length _size_ using the xref:nng_socket.5.adoc[socket] _s_. - -NOTE: The semantics of what sending a message means vary from protocol to -protocol, so examination of the protocol documentation is encouraged. -(For example, with an xref:nng_pub.7.adoc[_pub_] socket the data is broadcast, so that -any peers who have a suitable subscription will be able to receive it using -xref:nng_recv.3.adoc[`nng_recv()`] or a similar function.) -Furthermore, some protocols may not support sending data (such as -xref:nng_sub.7.adoc[_sub_]) or may require other conditions. -(For example, xref:nng_rep.7.adoc[_rep_] sockets cannot normally send data, -which are responses to requests, until they have first received a request.) - -The _flags_ may contain either of (or neither of) the following values: - -`NNG_FLAG_NONBLOCK`:: - The function returns immediately, regardless of whether - the socket is able to accept the data or not. If the socket is unable - to accept the data (such as if backpressure exists because the peers - are consuming messages too slowly, or no peer is present), then the - function will return with `NNG_EAGAIN`. If this flag is not specified, - then the function will block if such a condition exists. - -`NNG_FLAG_ALLOC`:: - The _data_ was allocated using xref:nng_alloc.3.adoc[`nng_alloc()`], or was - obtained from a call to xref:nng_recv.3.adoc[`nng_recv()`] with - the `NNG_FLAG_ALLOC` flag. - If this function returns success, then the _data_ is "owned" by the - function, and it will assume responsibility for calling - xref:nng_free.3.adoc[`nng_free()`] when it is no longer needed. - In the absence of this flag, the _data_ is copied by the implementation - before the function returns to the caller. - -TIP: The `NNG_FLAG_ALLOC` flag can be used to reduce data copies, thereby -increasing performance. - -NOTE: Regardless of the presence or absence of `NNG_FLAG_NONBLOCK`, there may -be queues between the sender and the receiver. -Furthermore, there is no guarantee that the message has actually been delivered. -Finally, with some protocols, the semantic is implicitly `NNG_FLAG_NONBLOCK`, -such as with xref:nng_pub.7.adoc[_pub_] sockets, which are best-effort delivery only. - -IMPORTANT: When using `NNG_FLAG_ALLOC`, it is important that the value of _size_ -match the actual allocated size of the data. -Using an incorrect size results -in unspecified behavior, which may include heap corruption, program crashes, -or trans-dimensional mutation of the program's author. - -== 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 value of _size_ is too large. -`NNG_ENOMEM`:: Insufficient memory is available. -`NNG_ENOTSUP`:: The protocol for socket _s_ does not support sending. -`NNG_ESTATE`:: The socket _s_ cannot send 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_recv.3.adoc[nng_recv(3)], -xref:nng_sendmsg.3.adoc[nng_sendmsg(3)], -xref:nng_strerror.3.adoc[nng_strerror(3)], -xref:nng_socket.5.adoc[nng_socket(5)], -xref:nng.7.adoc[nng(7)] diff --git a/docs/man/nng_send_aio.3.adoc b/docs/man/nng_send_aio.3.adoc deleted file mode 100644 index e8fc2005..00000000 --- a/docs/man/nng_send_aio.3.adoc +++ /dev/null @@ -1,91 +0,0 @@ -= nng_send_aio(3) -// -// Copyright 2018 Staysail Systems, Inc. -// Copyright 2018 Capitar IT Group BV -// -// 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_send_aio - send message asynchronously - -== SYNOPSIS - -[source, c] ----- -#include - -void nng_send_aio(nng_socket s, nng_aio *aio); ----- - -== DESCRIPTION - -The `nng_send_aio()` sends a xref:nng_msg.5.adoc[message] using the -xref:nng_socket.5.adoc[socket] _s_ asynchronously. - -The message to send must have previously been set on the _aio_ -using the xref:nng_aio_set_msg.3.adoc[`nng_aio_set_msg()`] function. -The function assumes ownership of the message. - -If the message was successfully queued for delivery to the socket, -then the _aio_ will be completed, and xref:nng_aio_result.3.adoc[`nng_aio_result()`] -will return zero. In this case the socket will dispose of the -message when it is finished with it. - -NOTE: The operation will be completed, and the callback associated -with the _aio_ executed, as soon as the socket accepts the message -for sending. -This does _not_ indicate that the message was actually delivered, as it -may still be buffered in the sending socket, buffered in the receiving -socket, or in flight over physical media. - -If the operation fails for any reason (including cancellation or timeout), -then the _aio_ callback will be executed and -xref:nng_aio_result.3.adoc[`nng_aio_result()`] -will return a non-zero error status. -In this case, the callback has a responsibility to retrieve the message from -the _aio_ with -xref:nng_aio_get_msg.3.adoc[`nng_aio_get_msg()`] and dispose of it appropriately. -(This may include retrying the send operation on the same or a different -socket, or deallocating the message with xref:nng_msg_free.3.adoc[`nng_msg_free()`].) - -NOTE: The semantics of what sending a message means varies from protocol to -protocol, so examination of the protocol documentation is encouraged. -(For example, with a xref:nng_pub.7.adoc[_pub_] socket the data is broadcast, so that -any peers who have a suitable subscription will be able to receive it using -xref:nng_recv.3.adoc[`nng_recv()`] or a similar function.) -Furthermore, some protocols may not support sending (such as -xref:nng_sub.7.adoc[_sub_]) or may require other conditions. -(For example, xref:nng_rep.7.adoc[_rep_] sockets cannot normally send data, which -are responses to requests, until they have first received a request.) - -== RETURN VALUES - -None. (The operation completes asynchronously.) - -== ERRORS - -[horizontal] -`NNG_ECANCELED`:: The operation was aborted. -`NNG_ECLOSED`:: The socket _s_ is not open. -`NNG_EMSGSIZE`:: The message is too large. -`NNG_ENOMEM`:: Insufficient memory is available. -`NNG_ENOTSUP`:: The protocol for socket _s_ does not support sending. -`NNG_ESTATE`:: The socket _s_ cannot send data in this state. -`NNG_ETIMEDOUT`:: The send timeout expired. - -== SEE ALSO - -[.text-left] -xref:nng_aio_get_msg.3.adoc[nng_aio_get_msg(3)], -xref:nng_aio_set_msg.3.adoc[nng_aio_set_msg(3)], -xref:nng_msg_alloc.3.adoc[nng_msg_alloc(3)], -xref:nng_strerror.3.adoc[nng_strerror(3)], -xref:nng_aio.5.adoc[nng_aio(5)], -xref:nng_msg.5.adoc[nng_msg(5)], -xref:nng_socket.5.adoc[nng_socket(5)], -xref:nng.7.adoc[nng(7)] diff --git a/docs/man/nng_sendmsg.3.adoc b/docs/man/nng_sendmsg.3.adoc deleted file mode 100644 index 5b7a73ee..00000000 --- a/docs/man/nng_sendmsg.3.adoc +++ /dev/null @@ -1,94 +0,0 @@ -= nng_sendmsg(3) -// -// Copyright 2018 Staysail Systems, Inc. -// Copyright 2018 Capitar IT Group BV -// -// 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_sendmsg - send message - -== SYNOPSIS - -[source, c] ----- -#include - -int nng_sendmsg(nng_socket s, nng_msg *msg, int flags); ----- - -== DESCRIPTION - -The `nng_sendmsg()` sends message _msg_ using the socket _s_. - -If the function returns zero, indicating it has accepted the message for -delivery, then the _msg_ is owned by the socket _s_, and the caller -must not make any further use of it. -The socket will free the message when it is finished. - -If the function returns non-zero, then it is the caller's responsibility -to dispose of the _msg_, which may include freeing it, sending it to -another socket, or simply trying again later. - -TIP: Using this function gives access to the message structure, and may -offer more functionality than the simpler xref:nng_send.3.adoc[`nng_send()`] function. - -NOTE: The semantics of what sending a message means vary from protocol to -protocol, so examination of the protocol documentation is encouraged. -(For example, with a xref:nng_pub.7.adoc[_pub_] socket the data is broadcast, so that -any peers who have a suitable subscription will be able to receive it using -xref:nng_recv.3.adoc[`nng_recv()`] or a similar function.) -Furthermore, some protocols may not support sending (such as -xref:nng_sub.7.adoc[_sub_]) or may require other conditions. -(For example, xref:nng_rep.7.adoc[_rep_] sockets cannot normally send data, which -are responses to requests, until they have first received a request.) - -The _flags_ may contain the following value: - -`NNG_FLAG_NONBLOCK`:: - The function returns immediately, regardless of whether - the socket is able to accept the data or not. - If the socket is unable to accept the data (such as if backpressure exists - because the peers are consuming messages too slowly, or no peer is present), - then the function will return with `NNG_EAGAIN`. - If this flag is not specified, then the function will block if such a - condition exists. - - -NOTE: Regardless of the presence or absence of `NNG_FLAG_NONBLOCK`, there may -be queues between the sender and the receiver. -Furthermore, there is no guarantee that the message has actually been delivered. -Finally, with some protocols, the semantic is implicitly `NNG_FLAG_NONBLOCK`, -such as with xref:nng_pub.7.adoc[_pub_] sockets, which are best-effort delivery only. - -== 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 value of _size_ is too large. -`NNG_ENOMEM`:: Insufficient memory is available. -`NNG_ENOTSUP`:: The protocol for socket _s_ does not support sending. -`NNG_ESTATE`:: The socket _s_ cannot send data in this state. -`NNG_ETIMEDOUT`:: The operation timed out. - -== SEE ALSO - -[.text-left] -xref:nng_msg_alloc.3.adoc[nng_msg_alloc(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_msg.5.adoc[nng_msg(5)], -xref:nng_socket.5.adoc[nng_socket(5)], -xref:nng.7.adoc[nng(7)] -- cgit v1.2.3-70-g09d2