poll.h

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 *
 * Copyright 2016 Samsung Electronics All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
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 * "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.
 *
 ****************************************************************************/
/****************************************************************************
 * 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
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#ifndef __INCLUDE_POLL_H
#define __INCLUDE_POLL_H

/****************************************************************************
 * Included Files
 ****************************************************************************/

#include <tinyara/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)     /* TinyAra does not make priority distinctions */
#define POLLRDNORM   (0x01)
#define POLLRDBAND   (0x01)
#define POLLPRI      (0x01)

#define POLLOUT      (0x02)     /* TinyAra 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 TinyAra 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 */
#ifdef CONFIG_NET_LWIP
    FAR void *scb;
#endif
};

/****************************************************************************
 * 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 */