select.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.
 * You may obtain a copy of the License at
 *
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 * 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.
 *
 ****************************************************************************/
/****************************************************************************
 * include/sys/select.h
 *
 *   Copyright (C) 2008-2009, 2011 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.
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 *    distribution.
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 ****************************************************************************/

#ifndef __INCLUDE_SYS_SELECT_H
#define __INCLUDE_SYS_SELECT_H

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

#include <tinyara/config.h>

#include <stdint.h>
#include <time.h>

#if CONFIG_NFILE_DESCRIPTORS > 0 || CONFIG_NSOCKET_DESCRIPTORS > 0

#if defined(CONFIG_DISABLE_POLL) && defined(CONFIG_CUSTOM_SOCKETS)

#include <net/lwip/sockets.h>

#else

/****************************************************************************
 * Pre-Processor Definitions
 ****************************************************************************/

/* Get the total number of descriptors that we will have to support */

#define __SELECT_NDESCRIPTORS (CONFIG_NFILE_DESCRIPTORS + CONFIG_NSOCKET_DESCRIPTORS)

/* We will use a 32-bit bitsets to represent the set of descriptors.  How
 * many uint32_t's do we need to span all descriptors?
 */

#if __SELECT_NDESCRIPTORS <= 32
#define __SELECT_NUINT32 1
#elif __SELECT_NDESCRIPTORS <= 64
#define __SELECT_NUINT32 2
#elif __SELECT_NDESCRIPTORS <= 96
#define __SELECT_NUINT32 3
#elif __SELECT_NDESCRIPTORS <= 128
#define __SELECT_NUINT32 4
#elif __SELECT_NDESCRIPTORS <= 160
#define __SELECT_NUINT32 5
#elif __SELECT_NDESCRIPTORS <= 192
#define __SELECT_NUINT32 6
#elif __SELECT_NDESCRIPTORS <= 224
#define __SELECT_NUINT32 7
#elif __SELECT_NDESCRIPTORS <= 256
#define __SELECT_NUINT32 8
#else
#warning "Large fd_set needed"
#endif

/* Standard helper macros */

#define FD_CLR(fd, set)   ((set)->fd_bits[(fd)/8]) &= ~(1 << ((fd) & 7))
#define FD_SET(fd, set)   ((set)->fd_bits[(fd)/8]) |= (1 << ((fd) & 7))
#define FD_ISSET(fd, set) ((set)->fd_bits[(fd)/8]) &  (1 << ((fd) & 7))
#define FD_ZERO(set)      memset(set, 0, sizeof(fd_set))

/****************************************************************************
 * Type Definitions
 ****************************************************************************/

typedef struct fd_set {
    uint8_t fd_bits[__SELECT_NUINT32 * 4];
} fd_set;

#endif                          /* CONFIG_DISABLE_POLL */

/****************************************************************************
 * Public Function Prototypes
 ****************************************************************************/

#undef EXTERN
#if defined(__cplusplus)
#define EXTERN extern "C"
extern "C" {
#else
#define EXTERN extern
#endif

EXTERN int select(int nfds, FAR fd_set *readfds, FAR fd_set *writefds, FAR fd_set *exceptfds, FAR struct timeval *timeout);

#undef EXTERN
#if defined(__cplusplus)
}
#endif

#endif                          /* CONFIG_NFILE_DESCRIPTORS || CONFIG_NSOCKET_DESCRIPTORS */

#endif                          /* __INCLUDE_SYS_SELECT_H */