diff options
author | Kevin Kirspel <kevin-kirspel@idexx.com> | 2016-12-21 11:01:26 -0800 |
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committer | Sebastian Huber <sebastian.huber@embedded-brains.de> | 2016-12-23 08:24:12 +0100 |
commit | 6959face72eeb3c0bf9e36eed3255ac9bd64424e (patch) | |
tree | 29be91e98f99d4012340118cf01c7727838134f5 /freebsd/sys/sys/pipe.h | |
parent | Add BRIDGE(4) support to configuration (diff) | |
download | rtems-libbsd-6959face72eeb3c0bf9e36eed3255ac9bd64424e.tar.bz2 |
PIPE(2): Import from FreeBSD
Diffstat (limited to 'freebsd/sys/sys/pipe.h')
-rw-r--r-- | freebsd/sys/sys/pipe.h | 142 |
1 files changed, 142 insertions, 0 deletions
diff --git a/freebsd/sys/sys/pipe.h b/freebsd/sys/sys/pipe.h new file mode 100644 index 00000000..444c8fbe --- /dev/null +++ b/freebsd/sys/sys/pipe.h @@ -0,0 +1,142 @@ +/*- + * 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. + * + * $FreeBSD$ + */ + +#ifndef _SYS_PIPE_H_ +#define _SYS_PIPE_H_ + +#ifndef _KERNEL +#error "no user-servicable parts inside" +#endif + +/* + * 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 + +#ifndef SMALL_PIPE_SIZE +#define SMALL_PIPE_SIZE PAGE_SIZE +#endif + +/* + * PIPE_MINDIRECT MUST be smaller than PIPE_SIZE and MUST be bigger + * than PIPE_BUF. + */ +#ifndef PIPE_MINDIRECT +#define PIPE_MINDIRECT 8192 +#endif + +#define PIPENPAGES (BIG_PIPE_SIZE / PAGE_SIZE + 1) + +/* + * See sys_pipe.c for info on what these limits mean. + */ +extern long maxpipekva; + +/* + * 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 */ +}; + +/* + * Information to support direct transfers between processes for pipes. + */ +struct pipemapping { + vm_size_t cnt; /* number of chars in buffer */ + vm_size_t pos; /* current position of transfer */ + int npages; /* number of pages */ + vm_page_t ms[PIPENPAGES]; /* pages in source process */ +}; + +/* + * 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_WANT 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_LOCKFL 0x100 /* Process has exclusive access to pointers/data. */ +#define PIPE_LWANT 0x200 /* Process wants exclusive access to pointers/data. */ +#define PIPE_DIRECTW 0x400 /* Pipe direct write active. */ +#define PIPE_DIRECTOK 0x800 /* Direct mode ok. */ + +/* + * Per-pipe data structure. + * Two of these are linked together to produce bi-directional pipes. + */ +struct pipe { + struct pipebuf pipe_buffer; /* data storage */ + struct pipemapping pipe_map; /* pipe mapping for direct I/O */ + struct selinfo pipe_sel; /* for compat with select */ + struct timespec pipe_atime; /* time of last access */ + struct timespec pipe_mtime; /* time of last modify */ + struct timespec pipe_ctime; /* time of status change */ + struct sigio *pipe_sigio; /* information for async I/O */ + struct pipe *pipe_peer; /* link with other direction */ + struct pipepair *pipe_pair; /* container structure pointer */ + u_int pipe_state; /* pipe status info */ + int pipe_busy; /* busy flag, mostly to handle rundown sanely */ + int pipe_present; /* still present? */ + ino_t pipe_ino; /* fake inode for stat(2) */ +}; + +/* + * Values for the pipe_present. + */ +#define PIPE_ACTIVE 1 +#define PIPE_CLOSING 2 +#define PIPE_FINALIZED 3 + +/* + * Container structure to hold the two pipe endpoints, mutex, and label + * pointer. + */ +struct pipepair { + struct pipe pp_rpipe; + struct pipe pp_wpipe; + struct mtx pp_mtx; + struct label *pp_label; +}; + +#define PIPE_MTX(pipe) (&(pipe)->pipe_pair->pp_mtx) +#define PIPE_LOCK(pipe) mtx_lock(PIPE_MTX(pipe)) +#define PIPE_UNLOCK(pipe) mtx_unlock(PIPE_MTX(pipe)) +#define PIPE_LOCK_ASSERT(pipe, type) mtx_assert(PIPE_MTX(pipe), (type)) + + +#endif /* !_SYS_PIPE_H_ */ |