root/include/linux/posix_types.h

/* */

INCLUDED FROM

   1 #ifndef _LINUX_POSIX_TYPES_H
   2 #define _LINUX_POSIX_TYPES_H
   3 
   4 /*
   5  * This file is generally used by user-level software, so you need to
   6  * be a little careful about namespace pollution etc.  Also, we cannot
   7  * assume GCC is being used.
   8  */
   9 
  10 #ifndef NULL
  11 # define NULL           ((void *) 0)
  12 #endif
  13 
  14 /*
  15  * This allows for 256 file descriptors: if NR_OPEN is ever grown
  16  * beyond that you'll have to change this too. But 256 fd's seem to be
  17  * enough even for such "real" unices like SunOS, so hopefully this is
  18  * one limit that doesn't have to be changed.
  19  *
  20  * Note that POSIX wants the FD_CLEAR(fd,fdsetp) defines to be in
  21  * <sys/time.h> (and thus <linux/time.h>) - but this is a more logical
  22  * place for them. Solved by having dummy defines in <sys/time.h>.
  23  */
  24 
  25 /*
  26  * Those macros may have been defined in <gnu/types.h>. But we always
  27  * use the ones here. 
  28  */
  29 #undef __NFDBITS
  30 #define __NFDBITS       (8 * sizeof(unsigned int))
  31 
  32 #undef __FD_SETSIZE
  33 #define __FD_SETSIZE    256
  34 
  35 #undef __FDSET_INTS
  36 #define __FDSET_INTS    (__FD_SETSIZE/__NFDBITS)
  37 
  38 #undef __FDELT
  39 #define __FDELT(d)      ((d) / __NFDBITS)
  40 
  41 #undef __FDMASK
  42 #define __FDMASK(d)     (1 << ((d) % __NFDBITS))
  43 
  44 typedef struct fd_set {
  45         unsigned int fds_bits [__FDSET_INTS];
  46 } __kernel_fd_set;
  47 
  48 #include <asm/posix_types.h>
  49 
  50 #endif /* _LINUX_POSIX_TYPES_H */

/* */