port_create(3C) Standard C Library Functions port_create(3C)NAMEport_create - create a port
SYNOPSIS
#include <port.h>
int port_create(void);
DESCRIPTION
The port_create() function establishes a queue that multiplexes events
from disjoint sources. Each source has a corresponding object type and
source-specific mechanism for associating an object with a port.
source object type association mechanism
PORT_SOURCE_AIO struct aiocb aio_read(3RT),
aio_write(3RT),
lio_listio(3RT)
PORT_SOURCE_FD file descriptor port_associate(3C)
PORT_SOURCE_TIMER timer_t timer_create(3RT)
PORT_SOURCE_USER uintptr_t port_send(3C)
PORT_SOURCE_ALERT uintptr_t port_alert(3C)
PORT_SOURCE_AIO events represent the completion of an asynchronous I/O
transaction. An asynchronous I/O transaction is associated with a port
by specifying SIGEV_PORT as its notification mechanism. See
aio_read(3RT), aio_write(3RT), lio_listio(3RT), and aio.h(3HEAD) for
details.
PORT_SOURCE_FD events represent a transition in the poll(2) status of a
given file descriptor. Once an event is delivered, the file descriptor
is no longer associated with the port. A file descriptor is associated
(or re-associated) with a port using the port_associate(3C) function.
PORT_SOURCE_TIMER events represent one or more timer expirations for a
given timer. A timer is associated with a port by specifying
SIGEV_PORT as its notification mechanism. See timer_create(3RT) for
more information.
PORT_SOURCE_USER events represent user-defined events. These events are
generated by port_send(3C) or port_sendn(3C).
PORT_SOURCE_ALERT events indicate that the port itself is in alert
mode. The mode of the port is changed with port_alert(3C).The
port_create() function returns a file descriptor that represents a
newly created port. The close(2) function destroys the port and frees
all allocated resources.
The port_get(3C) and port_getn(3C) functions retrieve events from a
port. They ignore non retrievable events (non-own or non-shareable
events).
As a port is represented by a file descriptor, ports are shared between
child and parent processes after fork(). Both can continue to asso‐
ciate sources with the port, both can receive events from the port, and
events associated with and/or generated by either process are retriev‐
able in the other. Since some events might not have meaning in both
parent and child, care must be taken when using ports after fork().
If a port is exported to other processes, the port is destroyed on last
close.
PORT_SOURCE_USER and PORT_SOURCE_ALERT events can be distributed across
processes. PORT_SOURCE_FD events can only be shared between processes
when child processes inherit opened file decriptors from the parent
process. See fork(2). PORT_SOURCE_TIMER and PORT_SOURCE_AIO cannot be
shared between processes.
RETURN VALUES
Upon succesful completion, the port_create() function returns a non-
negative value, the port identifier. Otherwise, −1 is returned and
errno is set to indicate the error.
ERRORS
The port_create() function will fail if:
EAGAIN The maximum allowable number of ports is currently open
in the system. The maximum allowable number of ports is
the minimum value of the project.max-port-ids resource
control. See setrctl(2) and rctladm(1M) for information
on using resource controls.
EMFILE The process has too many open descriptors.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
┌─────────────────────────────┬─────────────────────────────┐
│ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
├─────────────────────────────┼─────────────────────────────┤
│Architecture │all │
├─────────────────────────────┼─────────────────────────────┤
│Availability │SUNWcsr, SUNWhea │
├─────────────────────────────┼─────────────────────────────┤
│Interface Stability │Evolving │
├─────────────────────────────┼─────────────────────────────┤
│MT-Level │Safe │
└─────────────────────────────┴─────────────────────────────┘
SEE ALSOrctladm(1M), close(2), exit(2), fork(2), poll(2), setrctl(2),
aio_read(3RT), aio_write(3RT), aio.h(3HEAD), lio_listio(3RT),
port_get(3C), timer_create(3RT), attributes(5)SunOS 5.10 22 Feb 2005 port_create(3C)
