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

/*
 * Copyright (c) 2000 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) 1995, 1997 Apple Computer, Inc. All Rights Reserved */
/*
 * Copyright (c) 1990, 1993
 *	The Regents of the University of California.  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, 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	@(#)filedesc.h	8.1 (Berkeley) 6/2/93
 */

#ifndef _SYS_FILEDESC_H_
#define	_SYS_FILEDESC_H_

/*
 * This structure is used for the management of descriptors.  It may be
 * shared by multiple processes.
 *
 * A process is initially started out with NDFILE descriptors [XXXstored within
 * this structureXXX], selected to be enough for typical applications based on
 * the historical limit of 20 open files (and the usage of descriptors by
 * shells).  If these descriptors are exhausted, a larger descriptor table
 * may be allocated, up to a process' resource limit; [XXXthe internal arrays
 * are then unusedXXX].  The initial expansion is set to NDEXTENT; each time
 * it runs out, it is doubled until the resource limit is reached. NDEXTENT
 * should be selected to be the biggest multiple of OFILESIZE (see below)
 * that will fit in a power-of-two sized piece of memory.
 */
#define NDFILE		25		/* 125 bytes */
#define NDEXTENT	50		/* 250 bytes in 256-byte alloc. */ 

struct filedesc {
	struct	file **fd_ofiles;	/* file structures for open files */
	char	*fd_ofileflags;		/* per-process open file flags */
	struct	vnode *fd_cdir;		/* current directory */
	struct	vnode *fd_rdir;		/* root directory */
	int	fd_nfiles;		/* number of open files allocated */
	u_short	fd_lastfile;		/* high-water mark of fd_ofiles */
	u_short	fd_freefile;		/* approx. next free file */
	u_short	fd_cmask;		/* mask for file creation */
	u_short	fd_refcnt;		/* reference count */
};

/*
 * Per-process open flags.
 */
#define	UF_EXCLOSE 	0x01		/* auto-close on exec */
#define	UF_MAPPED 	0x02		/* mapped from device */
#define UF_RESERVED	0x04		/* open pending / in progress */

/*
 * Storage required per open file descriptor.
 */
#define OFILESIZE (sizeof(struct file *) + sizeof(char))

#ifdef KERNEL
/*
 * Kernel global variables and routines.
 */
extern int	dupfdopen __P((struct filedesc *fdp,
				int indx, int dfd, int mode, int error));
extern int	fdalloc __P((struct proc *p, int want, int *result));
extern void	fdrelse __P((struct proc *p, int fd));
extern int	fdavail __P((struct proc *p, int n));
extern int	fdgetf __P((struct proc *p, int fd, struct file **resultfp));
#define		fdfile(p, fd)					\
			(&(p)->p_fd->fd_ofiles[(fd)])
#define		fdflags(p, fd)					\
			(&(p)->p_fd->fd_ofileflags[(fd)])
extern int	falloc __P((struct proc *p,
				struct file **resultfp, int *resultfd));
extern void	ffree __P((struct file *fp));
extern struct	filedesc *fdcopy __P((struct proc *p));
extern void	fdfree __P((struct proc *p));
extern void	fdexec __P((struct proc *p));

#endif /* KERNEL */

#endif /* !_SYS_FILEDESC_H_ */
Commit	Line	Data
1c79356b A	1	/*
	2	* Copyright (c) 2000 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	/* Copyright (c) 1995, 1997 Apple Computer, Inc. All Rights Reserved */
	23	/*
	24	* Copyright (c) 1990, 1993
	25	* The Regents of the University of California. All rights reserved.
	26	*
	27	* Redistribution and use in source and binary forms, with or without
	28	* modification, are permitted provided that the following conditions
	29	* are met:
	30	* 1. Redistributions of source code must retain the above copyright
	31	* notice, 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. All advertising materials mentioning features or use of this software
	36	* must display the following acknowledgement:
	37	* This product includes software developed by the University of
	38	* California, Berkeley and its contributors.
	39	* 4. Neither the name of the University nor the names of its contributors
	40	* may be used to endorse or promote products derived from this software
	41	* without specific prior written permission.
	42	*
	43	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	44	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	45	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	46	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	47	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	48	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	49	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	50	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	51	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	52	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	53	* SUCH DAMAGE.
	54	*
	55	* @(#)filedesc.h 8.1 (Berkeley) 6/2/93
	56	*/
	57
	58	#ifndef _SYS_FILEDESC_H_
	59	#define _SYS_FILEDESC_H_
	60
	61	/*
	62	* This structure is used for the management of descriptors. It may be
	63	* shared by multiple processes.
	64	*
65	* A process is initially started out with NDFILE descriptors [XXXstored within
66	* this structureXXX], selected to be enough for typical applications based on
67	* the historical limit of 20 open files (and the usage of descriptors by
68	* shells). If these descriptors are exhausted, a larger descriptor table
69	* may be allocated, up to a process' resource limit; [XXXthe internal arrays
70	* are then unusedXXX]. The initial expansion is set to NDEXTENT; each time
71	* it runs out, it is doubled until the resource limit is reached. NDEXTENT
72	* should be selected to be the biggest multiple of OFILESIZE (see below)
73	* that will fit in a power-of-two sized piece of memory.
74	*/
75	#define NDFILE 25 /* 125 bytes */
76	#define NDEXTENT 50 /* 250 bytes in 256-byte alloc. */
77
78	struct filedesc {
79	struct file *fd_ofiles; / file structures for open files */
80	char fd_ofileflags; / per-process open file flags */
81	struct vnode fd_cdir; / current directory */
82	struct vnode fd_rdir; / root directory */
83	int fd_nfiles; /* number of open files allocated */
84	u_short fd_lastfile; /* high-water mark of fd_ofiles */
85	u_short fd_freefile; /* approx. next free file */
86	u_short fd_cmask; /* mask for file creation */
87	u_short fd_refcnt; /* reference count */
88	};
89
90	/*
91	* Per-process open flags.
92	*/
93	#define UF_EXCLOSE 0x01 /* auto-close on exec */
94	#define UF_MAPPED 0x02 /* mapped from device */
95	#define UF_RESERVED 0x04 /* open pending / in progress */
96
97	/*
98	* Storage required per open file descriptor.
99	*/
100	#define OFILESIZE (sizeof(struct file *) + sizeof(char))
101
102	#ifdef KERNEL
103	/*
104	* Kernel global variables and routines.
105	*/
106	extern int dupfdopen __P((struct filedesc *fdp,
107	int indx, int dfd, int mode, int error));
108	extern int fdalloc __P((struct proc p, int want, int result));
109	extern void fdrelse __P((struct proc *p, int fd));
110	extern int fdavail __P((struct proc *p, int n));
111	extern int fdgetf __P((struct proc p, int fd, struct file *resultfp));
112	#define fdfile(p, fd) \
113	(&(p)->p_fd->fd_ofiles[(fd)])
114	#define fdflags(p, fd) \
115	(&(p)->p_fd->fd_ofileflags[(fd)])
116	extern int falloc __P((struct proc *p,
117	struct file *resultfp, int resultfd));
118	extern void ffree __P((struct file *fp));
119	extern struct filedesc fdcopy __P((struct proc p));
120	extern void fdfree __P((struct proc *p));
121	extern void fdexec __P((struct proc *p));
122
123	#endif /* KERNEL */
124
125	#endif /* !_SYS_FILEDESC_H_ */