[apple/xnu.git] / bsd / sys / pipe.h

/*
 * Copyright (c) 2004-2005 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * The contents of this file constitute Original Code as defined in and
 * are subject to the Apple Public Source License Version 1.1 (the
 * "License").  You may not use this file except in compliance with the
 * License.  Please obtain a copy of the License at
 * http://www.apple.com/publicsource and read it before using this file.
 * 
 * This Original Code and all software distributed under the License are
 * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
 * License for the specific language governing rights and limitations
 * under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */
/*
 * 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: src/sys/sys/pipe.h,v 1.24 2003/08/13 20:01:38 alc Exp $
 */

#ifndef _SYS_PIPE_H_
#define _SYS_PIPE_H_

#ifdef	KERNEL
#include <libkern/locks.h>
#endif
#include <sys/queue.h>			/* for TAILQ macros */
#include <sys/ev.h>
#include <sys/cdefs.h>

/*
 * 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)

/*
 * 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 */
};


#ifdef PIPE_DIRECT
/*
 * Information to support direct transfers between processes for pipes.
 */
/* LP64todo - not 64bit safe */
struct pipemapping {
	vm_offset_t	kva;		/* kernel virtual address */
	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 */
};
#endif

/*
 * 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. */
#define PIPE_KNOTE     0x1000   /* Pipe has kernel events activated */

#ifdef	KERNEL
/*
 * Per-pipe data structure.
 * Two of these are linked together to produce bi-directional pipes.
 */
struct pipe {
	struct	pipebuf pipe_buffer;	/* data storage */
#ifdef PIPE_DIRECT
	struct	pipemapping pipe_map;	/* pipe mapping for direct I/O */
#endif
	struct	selinfo pipe_sel;	/* for compat with select */
	pid_t	pipe_pgid;		/* information for async I/O */
	struct	pipe *pipe_peer;	/* link with other direction */
	u_int	pipe_state;		/* pipe status info */
	int	pipe_busy;		/* busy flag, mostly to handle rundown sanely */
#ifdef MAC
	struct	label *pipe_label;	/* pipe MAC label - shared */
#endif
	TAILQ_HEAD(,eventqelt) pipe_evlist;
	lck_mtx_t *pipe_mtxp;		/* shared mutex between both pipes */
};

#define PIPE_MTX(pipe)		((pipe)->pipe_mtxp)

#define PIPE_LOCK(pipe)		lck_mtx_lock(PIPE_MTX(pipe))
#define PIPE_UNLOCK(pipe)	lck_mtx_unlock(PIPE_MTX(pipe))
#define PIPE_LOCK_ASSERT(pipe, type)  lck_mtx_assert(PIPE_MTX(pipe), (type))

__BEGIN_DECLS
extern int pipe_stat(struct pipe *, struct stat *);
__END_DECLS

#endif	/* KERNEL */

#endif /* !_SYS_PIPE_H_ */
Commit	Line	Data
91447636 A	1	/*
	2	* Copyright (c) 2004-2005 Apple Computer, Inc. All rights reserved.
	3	*
	4	* @APPLE_LICENSE_HEADER_START@
	5	*
	6	* The contents of this file constitute Original Code as defined in and
	7	* are subject to the Apple Public Source License Version 1.1 (the
	8	* "License"). You may not use this file except in compliance with the
	9	* License. Please obtain a copy of the License at
	10	* http://www.apple.com/publicsource and read it before using this file.
	11	*
	12	* This Original Code and all software distributed under the License are
	13	* distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
	14	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
	15	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
	16	* FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
	17	* License for the specific language governing rights and limitations
	18	* under the License.
	19	*
	20	* @APPLE_LICENSE_HEADER_END@
	21	*/
	22	/*
	23	* Copyright (c) 1996 John S. Dyson
	24	* All rights reserved.
	25	*
	26	* Redistribution and use in source and binary forms, with or without
	27	* modification, are permitted provided that the following conditions
	28	* are met:
	29	* 1. Redistributions of source code must retain the above copyright
	30	* notice immediately at the beginning of the file, without modification,
	31	* this list of conditions, and the following disclaimer.
	32	* 2. Redistributions in binary form must reproduce the above copyright
	33	* notice, this list of conditions and the following disclaimer in the
	34	* documentation and/or other materials provided with the distribution.
	35	* 3. Absolutely no warranty of function or purpose is made by the author
	36	* John S. Dyson.
	37	* 4. This work was done expressly for inclusion into FreeBSD. Other use
	38	* is allowed if this notation is included.
	39	* 5. Modifications may be freely made to this file if the above conditions
	40	* are met.
	41	*
	42	* $FreeBSD: src/sys/sys/pipe.h,v 1.24 2003/08/13 20:01:38 alc Exp $
	43	*/
	44
	45	#ifndef _SYS_PIPE_H_
	46	#define _SYS_PIPE_H_
	47
	48	#ifdef KERNEL
	49	#include <libkern/locks.h>
	50	#endif
	51	#include <sys/queue.h> /* for TAILQ macros */
	52	#include <sys/ev.h>
	53	#include <sys/cdefs.h>
	54
	55	/*
	56	* Pipe buffer size, keep moderate in value, pipes take kva space.
	57	*/
	58	#ifndef PIPE_SIZE
	59	#define PIPE_SIZE 16384
	60	#endif
	61
	62	#ifndef BIG_PIPE_SIZE
	63	#define BIG_PIPE_SIZE (64*1024)
	64	#endif
65
66	#ifndef SMALL_PIPE_SIZE
67	#define SMALL_PIPE_SIZE PAGE_SIZE
68	#endif
69
70	/*
71	* PIPE_MINDIRECT MUST be smaller than PIPE_SIZE and MUST be bigger
72	* than PIPE_BUF.
73	*/
74	#ifndef PIPE_MINDIRECT
75	#define PIPE_MINDIRECT 8192
76	#endif
77
78	#define PIPENPAGES (BIG_PIPE_SIZE / PAGE_SIZE + 1)
79
80	/*
81	* Pipe buffer information.
82	* Separate in, out, cnt are used to simplify calculations.
83	* Buffered write is active when the buffer.cnt field is set.
84	*/
85	struct pipebuf {
86	u_int cnt; /* number of chars currently in buffer */
87	u_int in; /* in pointer */
88	u_int out; /* out pointer */
89	u_int size; /* size of buffer */
90	caddr_t buffer; /* kva of buffer */
91	};
92
93
94	#ifdef PIPE_DIRECT
95	/*
96	* Information to support direct transfers between processes for pipes.
97	*/
98	/* LP64todo - not 64bit safe */
99	struct pipemapping {
100	vm_offset_t kva; /* kernel virtual address */
101	vm_size_t cnt; /* number of chars in buffer */
102	vm_size_t pos; /* current position of transfer */
103	int npages; /* number of pages */
104	vm_page_t ms[PIPENPAGES]; /* pages in source process */
105	};
106	#endif
107
108	/*
109	* Bits in pipe_state.
110	*/
111	#define PIPE_ASYNC 0x004 /* Async? I/O. */
112	#define PIPE_WANTR 0x008 /* Reader wants some characters. */
113	#define PIPE_WANTW 0x010 /* Writer wants space to put characters. */
114	#define PIPE_WANT 0x020 /* Pipe is wanted to be run-down. */
115	#define PIPE_SEL 0x040 /* Pipe has a select active. */
116	#define PIPE_EOF 0x080 /* Pipe is in EOF condition. */
117	#define PIPE_LOCKFL 0x100 /* Process has exclusive access to pointers/data. */
118	#define PIPE_LWANT 0x200 /* Process wants exclusive access to pointers/data. */
119	#define PIPE_DIRECTW 0x400 /* Pipe direct write active. */
120	#define PIPE_DIRECTOK 0x800 /* Direct mode ok. */
121	#define PIPE_KNOTE 0x1000 /* Pipe has kernel events activated */
122
123	#ifdef KERNEL
124	/*
125	* Per-pipe data structure.
126	* Two of these are linked together to produce bi-directional pipes.
127	*/
128	struct pipe {
129	struct pipebuf pipe_buffer; /* data storage */
130	#ifdef PIPE_DIRECT
131	struct pipemapping pipe_map; /* pipe mapping for direct I/O */
132	#endif
133	struct selinfo pipe_sel; /* for compat with select */
134	pid_t pipe_pgid; /* information for async I/O */
135	struct pipe pipe_peer; / link with other direction */
136	u_int pipe_state; /* pipe status info */
137	int pipe_busy; /* busy flag, mostly to handle rundown sanely */
138	#ifdef MAC
139	struct label pipe_label; / pipe MAC label - shared */
140	#endif
141	TAILQ_HEAD(,eventqelt) pipe_evlist;
142	lck_mtx_t pipe_mtxp; / shared mutex between both pipes */
143	};
144
145	#define PIPE_MTX(pipe) ((pipe)->pipe_mtxp)
146
147	#define PIPE_LOCK(pipe) lck_mtx_lock(PIPE_MTX(pipe))
148	#define PIPE_UNLOCK(pipe) lck_mtx_unlock(PIPE_MTX(pipe))
149	#define PIPE_LOCK_ASSERT(pipe, type) lck_mtx_assert(PIPE_MTX(pipe), (type))
150
151	__BEGIN_DECLS
152	extern int pipe_stat(struct pipe , struct stat );
153	__END_DECLS
154
155	#endif /* KERNEL */
156
157	#endif /* !_SYS_PIPE_H_ */