ack/h/ocm_chan.h
1987-03-10 09:24:02 +00:00

53 lines
1.8 KiB
C

/* $Header$ */
/*
* (c) copyright 1987 by the Vrije Universiteit, Amsterdam, The Netherlands.
* See the copyright notice in the ACK home directory, in the file "Copyright".
*/
/* ocm_chan.h - channel definitions */
#include <stdio.h>
#include "ocm_parco.h"
typedef union channel {
struct { /* Interprocess channel */
char _type; /* Channel type, see note */
char synch; /* State in channel synchronization */
long val; /* Transmitted value */
} c;
struct { /* File channel */
char _type; /* Dummy field, see note */
char index; /* Index in the file array */
char flgs; /* Status flags: in use & readahead */
char preread; /* Possible preread character */
} f;
} chan;
#define type c._type /* Channel type */
/* Note: The channel type should not be part of each structure in chan. But
* the C alignment rules would make chan about 50% bigger if we had done it
* the right way. Note that the order of fields in a struct cannot be a problem
* as long as struct c is the largest within the union.
*/
#define C_T_CHAN 0 /* Type of a interprocess channel */
#define C_T_FILE 1 /* Type of a file channel */
#define C_S_FREE 0 /* IP channel is free */
#define C_S_ANY 1 /* IP channel contains data */
#define C_S_ACK 2 /* IP channel data is removed */
#define C_F_EOF (-1L) /* File channel returns EOF */
#define C_F_TEXT (-2L) /* File channel becomes line oriented */
#define C_F_RAW (-3L) /* File channel becomes character oriented */
#define C_F_INUSE 0x01 /* File channel is connected to a UNIX file */
#define C_F_READAHEAD 0x02 /* File channel has a preread character */
extern chan file[20]; /* Array of file channels */
extern FILE *unix_file[20]; /* Pointers to buffered UNIX files */
void c_init();
void chan_in(), cbyte_in(), c_wa_in(), c_ba_in();
void chan_out(), c_wa_out(), c_ba_out();
int chan_any();