64ecd1399f
is more likely to be noticed with signed types. - Make amountpipekva a long as well to match maxpipekva. Discussed with: bde
142 lines
4.2 KiB
C
142 lines
4.2 KiB
C
/*-
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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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* $FreeBSD$
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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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#error "no user-servicable parts inside"
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#endif
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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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#ifndef SMALL_PIPE_SIZE
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#define SMALL_PIPE_SIZE PAGE_SIZE
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#endif
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/*
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* PIPE_MINDIRECT MUST be smaller than PIPE_SIZE and MUST be bigger
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* than PIPE_BUF.
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*/
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#ifndef PIPE_MINDIRECT
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#define PIPE_MINDIRECT 8192
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#endif
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#define PIPENPAGES (BIG_PIPE_SIZE / PAGE_SIZE + 1)
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/*
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* See sys_pipe.c for info on what these limits mean.
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*/
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extern long maxpipekva;
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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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* Information to support direct transfers between processes for pipes.
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*/
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struct pipemapping {
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vm_size_t cnt; /* number of chars in buffer */
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vm_size_t pos; /* current position of transfer */
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int npages; /* number of pages */
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vm_page_t ms[PIPENPAGES]; /* pages in source process */
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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_WANT 0x020 /* Pipe is wanted to be run-down. */
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#define PIPE_SEL 0x040 /* Pipe has a select active. */
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#define PIPE_EOF 0x080 /* Pipe is in EOF condition. */
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#define PIPE_LOCKFL 0x100 /* Process has exclusive access to pointers/data. */
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#define PIPE_LWANT 0x200 /* Process wants exclusive access to pointers/data. */
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#define PIPE_DIRECTW 0x400 /* Pipe direct write active. */
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#define PIPE_DIRECTOK 0x800 /* Direct mode ok. */
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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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struct pipe {
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struct pipebuf pipe_buffer; /* data storage */
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struct pipemapping pipe_map; /* pipe mapping for direct I/O */
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struct selinfo pipe_sel; /* for compat with select */
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struct timespec pipe_atime; /* time of last access */
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struct timespec pipe_mtime; /* time of last modify */
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struct timespec pipe_ctime; /* time of status change */
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struct sigio *pipe_sigio; /* information for async I/O */
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struct pipe *pipe_peer; /* link with other direction */
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struct pipepair *pipe_pair; /* container structure pointer */
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u_int pipe_state; /* pipe status info */
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int pipe_busy; /* busy flag, mostly to handle rundown sanely */
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int pipe_present; /* still present? */
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};
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/*
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* Values for the pipe_present.
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*/
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#define PIPE_ACTIVE 1
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#define PIPE_CLOSING 2
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#define PIPE_FINALIZED 3
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/*
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* Container structure to hold the two pipe endpoints, mutex, and label
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* pointer.
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*/
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struct pipepair {
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struct pipe pp_rpipe;
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struct pipe pp_wpipe;
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struct mtx pp_mtx;
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struct label *pp_label;
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};
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#define PIPE_MTX(pipe) (&(pipe)->pipe_pair->pp_mtx)
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#define PIPE_LOCK(pipe) mtx_lock(PIPE_MTX(pipe))
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#define PIPE_UNLOCK(pipe) mtx_unlock(PIPE_MTX(pipe))
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#define PIPE_LOCK_ASSERT(pipe, type) mtx_assert(PIPE_MTX(pipe), (type))
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#endif /* !_SYS_PIPE_H_ */
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