freertos_select/sys/select.h

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#ifndef _SYS_SELECT_H_
#define _SYS_SELECT_H_
 
/* We can actually pull the FD Set macros from here */
#include <sys/types.h>
 
#ifdef __cplusplus
extern "C" {
#endif
 
#ifndef  _SYS_TYPES_FD_SET
// This is probably a very old armgcc that does not define the FD_SET macros.
 
#  define       NBBY    8               /* number of bits in a byte */
/*
 * Select uses bit masks of file descriptors in longs.
 * These macros manipulate such bit fields (the filesystem macros use chars).
 * FD_SETSIZE may be defined by the user, but the default here
 * should be >= NOFILE (param.h).
 */
#  ifndef       FD_SETSIZE
#       define  FD_SETSIZE      64
#  endif
 
typedef long    fd_mask;
#  define       NFDBITS (sizeof (fd_mask) * NBBY)       /* bits per mask */
#  ifndef       howmany
#       define  howmany(x,y)    (((x)+((y)-1))/(y))
#  endif
 
/* We use a macro for fd_set so that including Sockets.h afterwards
   can work.  */
typedef struct _types_fd_set {
        fd_mask fds_bits[howmany(FD_SETSIZE, NFDBITS)];
} _types_fd_set;
 
#define fd_set _types_fd_set
 
#  define       FD_SET(n, p)    ((p)->fds_bits[(n)/NFDBITS] |= (1L << ((n) % NFDBITS)))
#  define       FD_CLR(n, p)    ((p)->fds_bits[(n)/NFDBITS] &= ~(1L << ((n) % NFDBITS)))
#  define       FD_ISSET(n, p)  ((p)->fds_bits[(n)/NFDBITS] & (1L << ((n) % NFDBITS)))
#  define       FD_ZERO(p)      (__extension__ (void)({ \
     size_t __i; \
     char *__tmp = (char *)p; \
     for (__i = 0; __i < sizeof (*(p)); ++__i) \
       *__tmp++ = 0; \
}))
 
#endif  // !defined _SYS_TYPES_FD_SET
 
int select(int nfds, fd_set *readfds, fd_set *writefds,
           fd_set *exceptfds, struct timeval *timeout);
 
#ifdef __cplusplus
}
#endif
 
#endif /* _SYS_SELECT_H_ */