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/*
* Mach Operating System
* Copyright (c) 1991,1990 Carnegie Mellon University
* All Rights Reserved.
*
* Permission to use, copy, modify and distribute this software and its
* documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
* ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* Carnegie Mellon requests users of this software to return to
*
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
*
* any improvements or extensions that they make and grant Carnegie Mellon
* the rights to redistribute these changes.
*/
/*
* Author: David B. Golub, Carnegie Mellon University
* Date: 7/90
*/
#ifndef _DEVICE_CIRBUF_H_
#define _DEVICE_CIRBUF_H_
/*
* Circular buffers for TTY
*/
struct cirbuf {
char * c_start; /* start of buffer */
char * c_end; /* end of buffer + 1*/
char * c_cf; /* read pointer */
char * c_cl; /* write pointer */
short c_cc; /* current number of characters
(compatibility) */
short c_hog; /* max ever */
};
/*
* Exported routines
*/
extern int putc(int, struct cirbuf *);
extern int getc(struct cirbuf *);
extern int q_to_b(struct cirbuf *, char *, int);
extern int b_to_q(char *, int, struct cirbuf *);
extern int nqdb(struct cirbuf *, int);
extern void ndflush(struct cirbuf *, int);
extern void cb_clear(struct cirbuf *);
extern void cb_alloc(struct cirbuf *, int);
extern void cb_free(struct cirbuf *);
#endif /* _DEVICE_CIRBUF_H_ */
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