Source to include/select.h

0001  /*
0002   * select.h
0003   *	Definitions for select() operations
0004   */
0005  #ifndef _SELECT_H
0006  #define _SELECT_H
0007  #include <sys/types.h>
0008  #include <sys/param.h>
0009  #include <time.h>
0010  
0011  /*
0012   * By default, size of a file descriptor set.  May be overriden.
0013   * Must be a power of two, and a multiple of FDBITS.
0014   */
0015  #ifndef FD_SETSIZE
0016  #define FD_SETSIZE (64)
0017  #endif
0018  
0019  /*
0020   * Bits per slot (uint) in an fd_set
0021   */
0022  #define FDBITS (sizeof(uint) * NBBY)
0023  
0024  typedef struct fd_set {
0025  	uint _fds[FD_SETSIZE / FDBITS];
0026  } fd_set;
0027  
0028  extern int select(uint, fd_set *, fd_set *, fd_set *, struct timeval *);
0029  
0030  #define FD_ISSET(idx, p) \
0031  	((p)->_fds[(idx) / FDBITS] & \
0032  		(1 << ((idx) & (FDBITS - 1))))
0033  
0034  #define FD_SET(idx, p) \
0035  	((p)->_fds[(idx) / FDBITS] |= \
0036  		(1 << ((idx) & (FDBITS - 1))))
0037  
0038  #define FD_CLR(idx, p) \
0039  	((p)->_fds[(idx) / FDBITS] &= \
0040  		~(1 << ((idx) & (FDBITS - 1))))
0041  
0042  #define FD_ZERO(p) bzero((p), sizeof(fd_set))
0043  
0044   
0045  /*
0046   * Aliases for some access bits we use for our own purposes
0047   */
0048  #define ACC_EXCEP ACC_EXEC
0049  #define ACC_UNSUPP ACC_SYM	/* Internal */
0050  
0051  #ifdef _SELFS_INTERNAL
0052  
0053  /*
0054   * Format of messages used to control selfs
0055   */
0056  
0057  /*
0058   * This is the format of data returned from an FS_READ to a client.  It
0059   * indicates which sources satisfied the select request.  Zero (for timeout)
0060   * or more of these will be returned as the FS_READ data.
0061   */
0062  struct select_complete {
0063  	uint sc_index;		/* Index of client connection */
0064  	uint sc_mask;		/* Mask of satisfied events */
0065  	ulong sc_iocount;	/* # message exchanges seen */
0066  };
0067  
0068  /*
0069   * A server will write one or more of these to selfs to indicate
0070   * events which should awake a client.
0071   */
0072  struct select_event {
0073  	long se_clid;		/* Client's connection ID */
0074  	ulong se_key;		/* Magic # to inhibit bogus clid's */
0075  	uint se_index;		/* Index of client's server connection */
0076  	uint se_mask;		/* Mask of events which have occurred */
0077  	ulong se_iocount;	/* Indicated sc_iocount for this event */
0078  };
0079  
0080  /*
0081   * While not a struct, the format of the data which a client writes to a
0082   * server in an FS_WSTAT message is:
0083   *  select=<mask>,<host>,<se_clid>,<se_index>,<key>
0084   * or:
0085   *  unselect=<mask>,<host>,<se_clid>,<se_index>,<key>
0086   * The server's iocount is expected to count up from 0 starting from this
0087   * point.
0088   */
0089  
0090  #endif /* _SELFS_INTERNAL */
0091  
0092  #endif /* _SELECT_H */