2 * Copyright (c) 1996 John S. Dyson
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice immediately at the beginning of the file, without modification,
10 * this list of conditions, and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 3. Absolutely no warranty of function or purpose is made by the author
16 * 4. This work was done expressly for inclusion into FreeBSD. Other use
17 * is allowed if this notation is included.
18 * 5. Modifications may be freely made to this file if the above conditions
21 * $FreeBSD: src/sys/sys/pipe.h,v 1.16 1999/12/29 04:24:45 peter Exp $
22 * $DragonFly: src/sys/sys/pipe.h,v 1.10 2006/06/10 20:00:17 dillon Exp $
28 #if defined(_KERNEL) || defined(_KERNEL_STRUCTURES)
31 #include <sys/types.h>
34 #include <sys/time.h> /* for struct timespec */
37 #include <sys/event.h> /* for struct kqinfo */
40 #include <sys/xio.h> /* for struct xio */
42 #ifndef _SYS_THREAD_H_
43 #include <sys/thread.h> /* for struct lwkt_token */
45 #ifndef _MACHINE_PARAM_H_
46 #include <machine/param.h> /* for PAGE_SIZE */
50 * Pipe buffer size, keep moderate in value, pipes take kva space.
51 * Must be a multiple of PAGE_SIZE.
54 #define PIPE_SIZE 16384
58 #define BIG_PIPE_SIZE (64*1024)
61 #if PIPE_SIZE < PAGE_SIZE
62 #error "PIPE_SIZE is too small for this architecture"
66 * Pipe buffer information.
67 * Separate in, out, cnt are used to simplify calculations.
68 * Buffered write is active when the buffer.cnt field is set.
71 u_int rindex
; /* FIFO read index */
72 u_int dummy1
[3]; /* cache-align */
73 u_int windex
; /* FIFO write index */
74 u_int dummy2
[3]; /* cache-align */
75 u_int size
; /* size of buffer */
76 caddr_t buffer
; /* kva of buffer */
77 struct vm_object
*object
; /* VM object containing buffer */
83 #define PIPE_ASYNC 0x0004 /* Async? I/O */
84 #define PIPE_WANTR 0x0008 /* Reader wants some characters */
85 #define PIPE_WANTW 0x0010 /* Writer wants space to put characters */
86 #define PIPE_REOF 0x0040 /* Pipe is in EOF condition (read EOF) */
87 #define PIPE_WEOF 0x0080 /* Pipe is in EOF condition (write shutdown) */
88 #define PIPE_CLOSED 0x1000 /* Pipe has been closed */
91 * Per-pipe data structure.
92 * Two of these are linked together to produce bi-directional pipes.
95 struct pipebuf pipe_buffer
; /* data storage */
96 struct kqinfo pipe_kq
; /* for compat with select/poll/kq */
97 struct timespec pipe_atime
; /* time of last access */
98 struct timespec pipe_mtime
; /* time of last modify */
99 struct timespec pipe_ctime
; /* time of status change */
100 struct sigio
*pipe_sigio
; /* information for async I/O */
101 struct pipe
*pipe_peer
; /* link with other direction */
102 u_int pipe_state
; /* pipe status info */
103 int pipe_rip
; /* read uio in-progress */
104 int pipe_wip
; /* write uio in-progress */
105 u_int pipe_wantwcnt
; /* for resize */
106 struct lwkt_token pipe_rlock
; /* rindex locked */
107 struct lwkt_token pipe_wlock
; /* windex locked */
108 struct lock
*pipe_slock
; /* state locked (shared w/peer) */
111 #endif /* _KERNEL || _KERNEL_STRUCTURES */
112 #endif /* !_SYS_PIPE_H_ */