incubator-nuttx/include/sys/poll.h

153 lines
4.8 KiB
C

/****************************************************************************
* include/sys/poll.h
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
#ifndef __INCLUDE_SYS_POLL_H
#define __INCLUDE_SYS_POLL_H
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <nuttx/compiler.h>
#include <stdint.h>
#include <signal.h>
#include <semaphore.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* Poll event definitions:
*
* POLLIN
* Data other than high-priority data may be read without blocking.
* POLLRDNORM
* Normal data may be read without blocking.
* POLLRDBAND
* Priority data may be read without blocking.
* POLLPRI
* High priority data may be read without blocking.
*
* POLLOUT
* Normal data may be written without blocking.
* POLLWRNORM
* Equivalent to POLLOUT.
* POLLWRBAND
* Priority data may be written.
*
* POLLERR
* An error has occurred (revents only).
* POLLHUP
* Device has been disconnected (revents only).
* POLLNVAL
* Invalid fd member (revents only).
*/
#define POLLIN (0x01) /* NuttX does not make priority distinctions */
#define POLLRDNORM (0x01)
#define POLLRDBAND (0x01)
#define POLLPRI (0x02)
#define POLLOUT (0x04) /* NuttX does not make priority distinctions */
#define POLLWRNORM (0x04)
#define POLLWRBAND (0x04)
#define POLLERR (0x08)
#define POLLHUP (0x10)
#define POLLRDHUP (0x10) /* NuttX does not support shutdown(fd, SHUT_RD) */
#define POLLNVAL (0x20)
#define POLLFD (0x00)
#define POLLFILE (0x40)
#define POLLSOCK (0x80)
#define POLLMASK (0xC0)
/****************************************************************************
* Public Type Definitions
****************************************************************************/
/* The number of poll descriptors (required by poll() specification */
typedef unsigned int nfds_t;
/* In the standard poll() definition, the size of the event set is 'short'.
* Here we pick the smallest storage element that will contain all of the
* poll events.
*/
typedef uint8_t pollevent_t;
/* This is the NuttX variant of the standard pollfd structure. The poll()
* interfaces receive a variable length array of such structures.
*
* REVISIT: In a multi-threaded environment, one use case might be to share
* a single, array of struct pollfd in poll calls on different threads.
* That use case is not supportable with this variant due way in which the
* non-standard internal fields are used in the implementation of poll().
*/
struct pollfd
{
/* Standard fields */
int fd; /* The descriptor being polled */
pollevent_t events; /* The input event flags */
pollevent_t revents; /* The output event flags */
/* Non-standard fields used internally by NuttX. */
FAR void *ptr; /* The psock or file being polled */
FAR sem_t *sem; /* Pointer to semaphore used to post output event */
FAR void *priv; /* For use by drivers */
};
/****************************************************************************
* Public Data
****************************************************************************/
#undef EXTERN
#if defined(__cplusplus)
#define EXTERN extern "C"
extern "C"
{
#else
#define EXTERN extern
#endif
/****************************************************************************
* Public Function Prototypes
****************************************************************************/
int poll(FAR struct pollfd *fds, nfds_t nfds, int timeout);
int ppoll(FAR struct pollfd *fds, nfds_t nfds,
FAR const struct timespec *timeout_ts,
FAR const sigset_t *sigmask);
#undef EXTERN
#if defined(__cplusplus)
}
#endif
#endif /* __INCLUDE_SYS_POLL_H */