|
|
/****************************************************************************
* include/poll.h
*
* Copyright (C) 2008-2009 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
#ifndef __INCLUDE_POLL_H
#define __INCLUDE_POLL_H
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <stdint.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 (0x01)
#define POLLOUT (0x02) /* NuttX does not make priority distinctions */
#define POLLWRNORM (0x02)
#define POLLWRBAND (0x02)
#define POLLERR (0x04)
#define POLLHUP (0x08)
#define POLLNVAL (0x10)
/****************************************************************************
* 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. */
struct pollfd
{
int fd; /* The descriptor being polled */
sem_t *sem; /* Pointer to semaphore used to post output event */
pollevent_t events; /* The input event flags */
pollevent_t revents; /* The output event flags */
FAR void *priv; /* For use by drivers */
};
/****************************************************************************
* Public Variables
****************************************************************************/
#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);
#undef EXTERN
#if defined(__cplusplus)
}
#endif
#endif /* __INCLUDE_POLL_H */
|
