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Diffstat (limited to 'sys/sys/pipe.h')
| -rw-r--r-- | sys/sys/pipe.h | 96 |
1 files changed, 96 insertions, 0 deletions
diff --git a/sys/sys/pipe.h b/sys/sys/pipe.h new file mode 100644 index 0000000..d23f266 --- /dev/null +++ b/sys/sys/pipe.h @@ -0,0 +1,96 @@ +/* $OpenBSD: pipe.h,v 1.24 2020/01/24 11:07:41 anton Exp $ */ + +/* + * Copyright (c) 1996 John S. Dyson + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice immediately at the beginning of the file, without modification, + * this list of conditions, and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Absolutely no warranty of function or purpose is made by the author + * John S. Dyson. + * 4. This work was done expressly for inclusion into FreeBSD. Other use + * is allowed if this notation is included. + * 5. Modifications may be freely made to this file if the above conditions + * are met. + */ + +#ifndef _SYS_PIPE_H_ +#define _SYS_PIPE_H_ + +#ifndef _KERNEL +#include <sys/time.h> /* for struct timespec */ +#include <sys/selinfo.h> /* for struct selinfo */ +#endif /* _KERNEL */ + +#include <sys/sigio.h> /* for struct sigio_ref */ + +/* + * Pipe buffer size, keep moderate in value, pipes take kva space. + */ +#ifndef PIPE_SIZE +#define PIPE_SIZE 16384 +#endif + +#ifndef BIG_PIPE_SIZE +#define BIG_PIPE_SIZE (64*1024) +#endif + +/* + * Pipe buffer information. + * Separate in, out, cnt are used to simplify calculations. + * Buffered write is active when the buffer.cnt field is set. + */ +struct pipebuf { + u_int cnt; /* number of chars currently in buffer */ + u_int in; /* in pointer */ + u_int out; /* out pointer */ + u_int size; /* size of buffer */ + caddr_t buffer; /* kva of buffer */ +}; + +/* + * Bits in pipe_state. + */ +#define PIPE_ASYNC 0x004 /* Async? I/O. */ +#define PIPE_WANTR 0x008 /* Reader wants some characters. */ +#define PIPE_WANTW 0x010 /* Writer wants space to put characters. */ +#define PIPE_WANTD 0x020 /* Pipe is wanted to be run-down. */ +#define PIPE_SEL 0x040 /* Pipe has a select active. */ +#define PIPE_EOF 0x080 /* Pipe is in EOF condition. */ +#define PIPE_LOCK 0x100 /* Thread has exclusive I/O access. */ +#define PIPE_LWANT 0x200 /* Thread wants exclusive I/O access. */ + +/* + * Per-pipe data structure. + * Two of these are linked together to produce bi-directional pipes. + * + * Locking: + * I immutable after creation + * S sigio_lock + * p pipe_lock + */ +struct pipe { + struct rwlock *pipe_lock; + struct pipebuf pipe_buffer; /* [p] data storage */ + struct selinfo pipe_sel; /* [p] for compat with select */ + struct timespec pipe_atime; /* [p] time of last access */ + struct timespec pipe_mtime; /* [p] time of last modify */ + struct timespec pipe_ctime; /* [I] time of status change */ + struct sigio_ref pipe_sigio; /* [S] async I/O registration */ + struct pipe *pipe_peer; /* [p] link with other direction */ + u_int pipe_state; /* [p] pipe status info */ + int pipe_busy; /* [p] # readers/writers */ +}; + +#ifdef _KERNEL +void pipe_init(void); +#endif /* _KERNEL */ + +#endif /* !_SYS_PIPE_H_ */ |