Annotation of sys/sys/pipe.h, Revision 1.1
1.1 ! nbrk 1: /* $OpenBSD: pipe.h,v 1.13 2005/11/21 18:16:46 millert Exp $ */
! 2:
! 3: /*
! 4: * Copyright (c) 1996 John S. Dyson
! 5: * All rights reserved.
! 6: *
! 7: * Redistribution and use in source and binary forms, with or without
! 8: * modification, are permitted provided that the following conditions
! 9: * are met:
! 10: * 1. Redistributions of source code must retain the above copyright
! 11: * notice immediately at the beginning of the file, without modification,
! 12: * this list of conditions, and the following disclaimer.
! 13: * 2. Redistributions in binary form must reproduce the above copyright
! 14: * notice, this list of conditions and the following disclaimer in the
! 15: * documentation and/or other materials provided with the distribution.
! 16: * 3. Absolutely no warranty of function or purpose is made by the author
! 17: * John S. Dyson.
! 18: * 4. This work was done expressly for inclusion into FreeBSD. Other use
! 19: * is allowed if this notation is included.
! 20: * 5. Modifications may be freely made to this file if the above conditions
! 21: * are met.
! 22: */
! 23:
! 24: #ifndef _SYS_PIPE_H_
! 25: #define _SYS_PIPE_H_
! 26:
! 27: #ifndef _KERNEL
! 28: #include <sys/time.h> /* for struct timeval */
! 29: #include <sys/selinfo.h> /* for struct selinfo */
! 30: #include <uvm/uvm_extern.h> /* for vm_page_t */
! 31: #include <machine/param.h> /* for PAGE_SIZE */
! 32: #endif /* _KERNEL */
! 33:
! 34: /*
! 35: * Pipe buffer size, keep moderate in value, pipes take kva space.
! 36: */
! 37: #ifndef PIPE_SIZE
! 38: #define PIPE_SIZE 16384
! 39: #endif
! 40:
! 41: #ifndef BIG_PIPE_SIZE
! 42: #define BIG_PIPE_SIZE (64*1024)
! 43: #endif
! 44:
! 45: /*
! 46: * Pipe buffer information.
! 47: * Separate in, out, cnt are used to simplify calculations.
! 48: * Buffered write is active when the buffer.cnt field is set.
! 49: */
! 50: struct pipebuf {
! 51: u_int cnt; /* number of chars currently in buffer */
! 52: u_int in; /* in pointer */
! 53: u_int out; /* out pointer */
! 54: u_int size; /* size of buffer */
! 55: caddr_t buffer; /* kva of buffer */
! 56: };
! 57:
! 58: /*
! 59: * Bits in pipe_state.
! 60: */
! 61: #define PIPE_ASYNC 0x004 /* Async? I/O. */
! 62: #define PIPE_WANTR 0x008 /* Reader wants some characters. */
! 63: #define PIPE_WANTW 0x010 /* Writer wants space to put characters. */
! 64: #define PIPE_WANT 0x020 /* Pipe is wanted to be run-down. */
! 65: #define PIPE_SEL 0x040 /* Pipe has a select active. */
! 66: #define PIPE_EOF 0x080 /* Pipe is in EOF condition. */
! 67: #define PIPE_LOCK 0x100 /* Process has exclusive access to pointers/data. */
! 68: #define PIPE_LWANT 0x200 /* Process wants exclusive access to pointers/data. */
! 69:
! 70: /*
! 71: * Per-pipe data structure.
! 72: * Two of these are linked together to produce bi-directional pipes.
! 73: */
! 74: struct pipe {
! 75: struct pipebuf pipe_buffer; /* data storage */
! 76: struct selinfo pipe_sel; /* for compat with select */
! 77: struct timespec pipe_atime; /* time of last access */
! 78: struct timespec pipe_mtime; /* time of last modify */
! 79: struct timespec pipe_ctime; /* time of status change */
! 80: int pipe_pgid; /* process/group for async I/O */
! 81: struct pipe *pipe_peer; /* link with other direction */
! 82: u_int pipe_state; /* pipe status info */
! 83: int pipe_busy; /* busy flag, mostly to handle rundown sanely */
! 84: };
! 85:
! 86: #ifdef _KERNEL
! 87: void pipe_init(void);
! 88: #endif /* _KERNEL */
! 89:
! 90: #endif /* !_SYS_PIPE_H_ */
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