RPC_SVC_INPUT(3NSL) Networking Services Library Functions

NAME

rpc_svc_input, svc_add_input, svc_remove_input - declare or remove a
callback on a file descriptor

SYNOPSIS

#include <rpc/rpc.h>

typedef void (*svc_callback_t)(svc_input_id_t id, int fd,
unsigned int events, void *cookie);


svc_input_id_t svc_add_input(int fd, unsigned int revents,
svc_callback_t callback, void *cookie);


int svc_remove_input(svc_input_t id);

DESCRIPTION

The following RPC routines are used to declare or remove a callback
on a file descriptor.

Routines

See rpc(3NSL) for the definition of the SVCXPRT data structure.

svc_add_input()
This function is used to register a callback
function on a file descriptor, fd. The file
descriptor, fd, is the first parameter to be
passed to svc_add_input(). This callback
function will be automatically called if any of
the events specified in the events parameter
occur on this descriptor. The events parameter
is used to specify when the callback is
invoked. This parameter is a mask of poll
events to which the user wants to listen. See
poll(2) for further details of the events that
can be specified.

The callback to be invoked is specified using
the callback parameter. The cookie parameter
can be used to pass any data to the callback
function. This parameter is a user-defined
value which is passed as an argument to the
callback function, and it is not used by the
Sun RPC library itself.

Several callbacks can be registered on the same
file descriptor as long as each callback
registration specifies a separate set of event
flags.

The callback function is called with the
registration id, the fd file descriptor, an
revents value, which is a bitmask of all events
concerning the file descriptor, and the cookie
user-defined value.

Upon successful completion, the function
returns a unique identifier for this
registration, that can be used later to remove
this callback. Upon failure, -1 is returned and
errno is set to indicate the error.

The svc_add_input() function will fail if:

EINVAL
The fd or events parameters are
invalid.


EEXIST
A callback is already registered to
the file descriptor with one of the
specified events.


ENOMEM
Memory is exhausted.


svc_remove_input()
This function is used to unregister a callback
function on a file descriptor, fd. The id
parameter specifies the registration to be
removed.

Upon successful completion, the function
returns zero. Upon failure, -1 is returned and
errno is set to indicate the error.

The svc_remove_input() function will fail if:

EINVAL
The id parameter is invalid.

ATTRIBUTES

See attributes(7) for descriptions of the following attributes:


+--------------------+-----------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+-----------------+
|Architecture | All |
+--------------------+-----------------+
|Interface Stability | Evolving |
+--------------------+-----------------+
|MT-Level | MT-Safe |
+--------------------+-----------------+

SEE ALSO

poll(2), rpc(3NSL), attributes(7)

January 6, 2003 RPC_SVC_INPUT(3NSL)