illumos: manual page: port

PORT_SEND(3C) Standard C Library Functions PORT_SEND(3C)

NAME

port_send, port_sendn - send a user-defined event to a port or list of
ports

SYNOPSIS

#include <port.h>

int port_send(int port, int events, void *user);

int port_sendn(int ports[], int errors[], uint_t nent,
int events, void *user);

DESCRIPTION

The port_send() function submits a user-defined event to a specified
port. The port argument is a file descriptor that represents a port. The
sent event has its portev_events member set to the value specified in the
events parameter and its portev_user member set to the value specified in
the user parameter. The portev_object member of an event sent with
port_send() is unspecified.

The port_sendn() function submits a user-defined event to multiple ports.
The ports argument is an array of file descriptors that represents ports
(see port_create(3C)). The nent argument specifies the number of file
descriptors in the ports[] array. An event is submitted to each specified
port. Each event has its portev_events member set to the value specified
in the events parameter and its portev_user member set to the value
specified in the user parameter. The portev_object member of events sent
with port_sendn() is unspecified.

A port that is in alert mode can be sent an event, but that event will
not be retrievable until the port has resumed normal operation. See
port_alert(3C).

RETURN VALUES

Upon successful completion, the port_send() function returns 0.
Otherwise, it returns -1 and sets errno to indicate the error.

The port_sendn() function returns the number of successfully submitted
events. A non-negative return value less than the nent argument
indicates that at least one error occurred. In this case, each element of
the errors[] array is filled in. An element of the errors[] array is set
to 0 if the event was successfully sent to the corresponding port in the
ports[] array, or is set to indicate the error if the event was not
successfully sent. If an error occurs, the port_sendn() function returns
-1 and sets errno to indicate the error.

ERRORS

The port_send() and port_sendn() functions will fail if:

EAGAIN
The maximum number of events per port is exceeded. The maximum
allowable number of events per port is the minimum value of the
process.max-port-events resource control at the time
port_create(3C) was used to create the port.

EBADF
The port file descriptor is not valid.

EBADFD
The port argument is not an event port file descriptor.

ENOMEM
There is not enough memory available to satisfy the request.

The port_sendn() function will fail if:

EFAULT
The ports[] pointer or errors[] pointer is not reasonable.

EINVAL
The value of the nent argument is 0.

EXAMPLES

Example 1: Use port_send() to send a user event (PORT_SOURCE_USER) to a

port.

The following example uses port_send() to send a user event
(PORT_SOURCE_USER) to a port and port_get() to retrieve it. The
portev_user and portev_events members of the port_event_t structure are
the same as the corresponding user and events arguments of the
port_send() function.

#include <port.h>

int myport;
port_event_t pe;
struct timespec timeout;
int ret;
void *user;

myport = port_create();
if (myport) {
/* port creation failed ... */
...
return(...);
}
...
events = 0x01; /* own event definition(s) */
user = <my_own_value>;
ret = port_send(myport, events, user);
if (ret == -1) {
/* error detected ... */
...
close(myport);
return (...);
}

/*
* The following code could also be executed from another thread or
* process.
*/
timeout.tv_sec = 1; /* user defined */
timeout.tv_nsec = 0;
ret = port_get(myport, &pe, &timeout);
if (ret == -1) {
/*
* error detected :
* - EINTR or ETIME : log error code and try again ...
* - Other kind of errors : may have to close the port ...
*/
return(...);
}

/*
* After port_get() returns successfully, the port_event_t
* structure will be filled with:
* pe.portev_source = PORT_SOURCE_USER
* pe.portev_events = 0x01
* pe.portev_object = unspecified
* pe.portev_user = <my_own_value>
*/
...
close(myport);

USAGE

See setrctl(2) and rctladm(8) for information on using resource controls.

ATTRIBUTES