99 lines
3.1 KiB
C
99 lines
3.1 KiB
C
/* $OpenBSD: pipe.h,v 1.29 2022/07/09 12:48:21 visa Exp $ */
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/*
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* Copyright (c) 1996 John S. Dyson
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice immediately at the beginning of the file, without modification,
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* this list of conditions, and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Absolutely no warranty of function or purpose is made by the author
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* John S. Dyson.
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* 4. This work was done expressly for inclusion into FreeBSD. Other use
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* is allowed if this notation is included.
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* 5. Modifications may be freely made to this file if the above conditions
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* are met.
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*/
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#ifndef _SYS_PIPE_H_
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#define _SYS_PIPE_H_
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#ifndef _KERNEL
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#include <sys/time.h> /* for struct timespec */
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#endif /* _KERNEL */
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#include <sys/event.h> /* for struct klist */
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#include <sys/sigio.h> /* for struct sigio_ref */
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/*
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* Pipe buffer size, keep moderate in value, pipes take kva space.
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*/
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#ifndef PIPE_SIZE
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#define PIPE_SIZE 16384
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#endif
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#ifndef BIG_PIPE_SIZE
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#define BIG_PIPE_SIZE (64*1024)
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#endif
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/*
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* Pipe buffer information.
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* Separate in, out, cnt are used to simplify calculations.
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* Buffered write is active when the buffer.cnt field is set.
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*/
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struct pipebuf {
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u_int cnt; /* number of chars currently in buffer */
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u_int in; /* in pointer */
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u_int out; /* out pointer */
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u_int size; /* size of buffer */
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caddr_t buffer; /* kva of buffer */
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};
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/*
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* Bits in pipe_state.
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*/
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#define PIPE_ASYNC 0x004 /* Async? I/O. */
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#define PIPE_WANTR 0x008 /* Reader wants some characters. */
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#define PIPE_WANTW 0x010 /* Writer wants space to put characters. */
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#define PIPE_WANTD 0x020 /* Pipe is wanted to be run-down. */
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#define PIPE_EOF 0x080 /* Pipe is in EOF condition. */
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#define PIPE_LOCK 0x100 /* Thread has exclusive I/O access. */
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#define PIPE_LWANT 0x200 /* Thread wants exclusive I/O access. */
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struct pipe_pair;
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/*
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* Per-pipe data structure.
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* Two of these are linked together to produce bi-directional pipes.
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*
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* Locking:
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* I immutable after creation
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* S sigio_lock
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* p pipe_lock
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*/
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struct pipe {
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struct rwlock *pipe_lock;
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struct pipebuf pipe_buffer; /* [p] data storage */
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struct klist pipe_klist; /* [p] list of knotes */
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struct timespec pipe_atime; /* [p] time of last access */
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struct timespec pipe_mtime; /* [p] time of last modify */
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struct timespec pipe_ctime; /* [I] time of status change */
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struct sigio_ref pipe_sigio; /* [S] async I/O registration */
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struct pipe *pipe_peer; /* [p] link with other direction */
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struct pipe_pair *pipe_pair; /* [I] pipe storage */
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u_int pipe_state; /* [p] pipe status info */
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int pipe_busy; /* [p] # readers/writers */
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};
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#ifdef _KERNEL
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void pipe_init(void);
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#endif /* _KERNEL */
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#endif /* !_SYS_PIPE_H_ */
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