lib/libasyn/asynchio.h

   1 /*      asynchio.h - Asynchronous I/O                   Author: Kees J. Bot
   2  *                                                              7 Jul 1997
   3  * Minix-vmd compatible asynchio(3) using BSD select(2).
   4  */
   5 #ifndef _SYS__ASYNCHIO_H
   6 #define _SYS__ASYNCHIO_H
   7
   8 #include <sys/select.h>                 /* for FD_SETSIZE */
   9
  10 #define SEL_READ        0               /* Code for a read. */
  11 #define SEL_WRITE       1               /* Code for a write. */
  12 #define SEL_EXCEPT      2               /* Code for some exception. */
  13 #define SEL_NR          3               /* Number of codes. */
  14
  15 struct _asynfd {
  16         int             afd_seen;       /* Set if we manage this descriptor. */
  17         int             afd_flags;      /* File flags by fcntl(fd, F_GETFL). */
  18         int             afd_state[SEL_NR];  /* Operation state. */
  19 };
  20
  21 typedef struct {
  22         int             asyn_more;      /* Set if more to do before blocking. */
  23         struct _asynfd  asyn_afd[FD_SETSIZE];
  24         fd_set          asyn_fdset[SEL_NR];     /* Select() fd sets. */
  25 } asynchio_t;
  26
  27 #define ASYN_INPROGRESS EAGAIN          /* Errno code telling "nothing yet." */
  28 #define ASYN_NONBLOCK   0x01            /* If asyn_wait() mustn't block. */
  29
  30 struct timeval;
  31
  32 void asyn_init(asynchio_t *_asyn);
  33 ssize_t asyn_read(asynchio_t *_asyn, int _fd, void *_buf, size_t _len);
  34 ssize_t asyn_write(asynchio_t *_asyn, int _fd, const void *_buf, size_t _len);
  35 int asyn_special(asynchio_t *_asyn, int _fd, int _op);
  36 int asyn_result(asynchio_t *_asyn, int _fd, int _op, int _result);
  37 int asyn_wait(asynchio_t *_asyn, int _flags, struct timeval *to);
  38 int asyn_cancel(asynchio_t *_asyn, int _fd, int _op);
  39 int asyn_pending(asynchio_t *_asyn, int _fd, int _op);
  40 int asyn_synch(asynchio_t *_asyn, int _fd);
  41 int asyn_close(asynchio_t *_asyn, int _fd);
  42
  43 #endif /* _SYS__ASYNCHIO_H */