1 /*- 2 * Copyright (c) 1996 John S. Dyson 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 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 15 * John S. Dyson. 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 19 * are met. 20 * 21 * $FreeBSD$ 22 */ 23 24 #ifndef _SYS_PIPE_H_ 25 #define _SYS_PIPE_H_ 26 27 /* 28 * Pipe buffer size, keep moderate in value, pipes take kva space. 29 */ 30 #ifndef PIPE_SIZE 31 #define PIPE_SIZE 16384 32 #endif 33 34 #ifndef BIG_PIPE_SIZE 35 #define BIG_PIPE_SIZE (64*1024) 36 #endif 37 38 #ifndef SMALL_PIPE_SIZE 39 #define SMALL_PIPE_SIZE PAGE_SIZE 40 #endif 41 42 /* 43 * PIPE_MINDIRECT MUST be smaller than PIPE_SIZE and MUST be bigger 44 * than PIPE_BUF. 45 */ 46 #ifndef PIPE_MINDIRECT 47 #define PIPE_MINDIRECT 8192 48 #endif 49 50 #define PIPENPAGES (BIG_PIPE_SIZE / PAGE_SIZE + 1) 51 52 #ifdef _KERNEL 53 /* 54 * See sys_pipe.c for info on what these limits mean. 55 */ 56 extern long maxpipekva; 57 extern struct fileops pipeops; 58 #endif 59 60 /* 61 * Pipe buffer information. 62 * Separate in, out, cnt are used to simplify calculations. 63 * Buffered write is active when the buffer.cnt field is set. 64 */ 65 struct pipebuf { 66 u_int cnt; /* number of chars currently in buffer */ 67 u_int in; /* in pointer */ 68 u_int out; /* out pointer */ 69 u_int size; /* size of buffer */ 70 caddr_t buffer; /* kva of buffer */ 71 }; 72 73 /* 74 * Information to support direct transfers between processes for pipes. 75 */ 76 struct pipemapping { 77 vm_size_t cnt; /* number of chars in buffer */ 78 vm_size_t pos; /* current position of transfer */ 79 int npages; /* number of pages */ 80 vm_page_t ms[PIPENPAGES]; /* pages in source process */ 81 }; 82 83 /* 84 * Bits in pipe_state. 85 */ 86 #define PIPE_ASYNC 0x004 /* Async? I/O. */ 87 #define PIPE_WANTR 0x008 /* Reader wants some characters. */ 88 #define PIPE_WANTW 0x010 /* Writer wants space to put characters. */ 89 #define PIPE_WANT 0x020 /* Pipe is wanted to be run-down. */ 90 #define PIPE_SEL 0x040 /* Pipe has a select active. */ 91 #define PIPE_EOF 0x080 /* Pipe is in EOF condition. */ 92 #define PIPE_LOCKFL 0x100 /* Process has exclusive access to pointers/data. */ 93 #define PIPE_LWANT 0x200 /* Process wants exclusive access to pointers/data. */ 94 #define PIPE_DIRECTW 0x400 /* Pipe direct write active. */ 95 #define PIPE_DIRECTOK 0x800 /* Direct mode ok. */ 96 97 /* 98 * Bits in pipe_type. 99 */ 100 #define PIPE_TYPE_NAMED 0x001 /* Is a named pipe. */ 101 102 /* 103 * Per-pipe data structure. 104 * Two of these are linked together to produce bi-directional pipes. 105 */ 106 struct pipe { 107 struct pipebuf pipe_buffer; /* data storage */ 108 struct pipemapping pipe_pages; /* wired pages for direct I/O */ 109 struct selinfo pipe_sel; /* for compat with select */ 110 struct timespec pipe_atime; /* time of last access */ 111 struct timespec pipe_mtime; /* time of last modify */ 112 struct timespec pipe_ctime; /* time of status change */ 113 struct sigio *pipe_sigio; /* information for async I/O */ 114 struct pipe *pipe_peer; /* link with other direction */ 115 struct pipepair *pipe_pair; /* container structure pointer */ 116 u_short pipe_state; /* pipe status info */ 117 u_char pipe_type; /* pipe type info */ 118 u_char pipe_present; /* still present? */ 119 int pipe_waiters; /* pipelock waiters */ 120 int pipe_busy; /* busy flag, mostly to handle rundown sanely */ 121 int pipe_wgen; /* writer generation for named pipe */ 122 ino_t pipe_ino; /* fake inode for stat(2) */ 123 }; 124 125 /* 126 * Values for the pipe_present. 127 */ 128 #define PIPE_ACTIVE 1 129 #define PIPE_CLOSING 2 130 #define PIPE_FINALIZED 3 131 132 /* 133 * Container structure to hold the two pipe endpoints, mutex, and label 134 * pointer. 135 */ 136 struct pipepair { 137 struct pipe pp_rpipe; 138 struct pipe pp_wpipe; 139 struct mtx pp_mtx; 140 struct label *pp_label; 141 }; 142 143 #define PIPE_MTX(pipe) (&(pipe)->pipe_pair->pp_mtx) 144 #define PIPE_LOCK(pipe) mtx_lock(PIPE_MTX(pipe)) 145 #define PIPE_UNLOCK(pipe) mtx_unlock(PIPE_MTX(pipe)) 146 #define PIPE_LOCK_ASSERT(pipe, type) mtx_assert(PIPE_MTX(pipe), (type)) 147 148 #ifdef _KERNEL 149 void pipe_dtor(struct pipe *dpipe); 150 int pipe_named_ctor(struct pipe **ppipe, struct thread *td); 151 void pipeselwakeup(struct pipe *cpipe); 152 #endif 153 #endif /* !_SYS_PIPE_H_ */ 154