bsd/sys/filedesc.h

   1 /*
   2  * Copyright (c) 2000-2003 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_OSREFERENCE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License.  The rights granted to you under the
  10  * License may not be used to create, or enable the creation or
  11  * redistribution of, unlawful or unlicensed copies of an Apple operating
  12  * system, or to circumvent, violate, or enable the circumvention or
  13  * violation of, any terms of an Apple operating system software license
  14  * agreement.
  15  *
  16  * Please obtain a copy of the License at
  17  * http://www.opensource.apple.com/apsl/ and read it before using this
  18  * file.
  19  *
  20  * The Original Code and all software distributed under the License are
  21  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  22  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  23  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  24  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  25  * Please see the License for the specific language governing rights and
  26  * limitations under the License.
  27  *
  28  * @APPLE_LICENSE_OSREFERENCE_HEADER_END@
  29  */
  30 /* Copyright (c) 1995, 1997 Apple Computer, Inc. All Rights Reserved */
  31 /*
  32  * Copyright (c) 1990, 1993
  33  *      The Regents of the University of California.  All rights reserved.
  34  *
  35  * Redistribution and use in source and binary forms, with or without
  36  * modification, are permitted provided that the following conditions
  37  * are met:
  38  * 1. Redistributions of source code must retain the above copyright
  39  *    notice, this list of conditions and the following disclaimer.
  40  * 2. Redistributions in binary form must reproduce the above copyright
  41  *    notice, this list of conditions and the following disclaimer in the
  42  *    documentation and/or other materials provided with the distribution.
  43  * 3. All advertising materials mentioning features or use of this software
  44  *    must display the following acknowledgement:
  45  *      This product includes software developed by the University of
  46  *      California, Berkeley and its contributors.
  47  * 4. Neither the name of the University nor the names of its contributors
  48  *    may be used to endorse or promote products derived from this software
  49  *    without specific prior written permission.
  50  *
  51  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  52  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  53  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  54  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  55  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  56  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  57  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  58  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  59  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  60  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  61  * SUCH DAMAGE.
  62  *
  63  *      @(#)filedesc.h  8.1 (Berkeley) 6/2/93
  64  */
  65
  66 #ifndef _SYS_FILEDESC_H_
  67 #define _SYS_FILEDESC_H_
  68
  69 #include <sys/appleapiopts.h>
  70
  71 #ifdef __APPLE_API_UNSTABLE
  72 /*
  73  * This structure is used for the management of descriptors.  It may be
  74  * shared by multiple processes.
  75  *
  76  * A process is initially started out with NDFILE descriptors [XXXstored within
  77  * this structureXXX], selected to be enough for typical applications based on
  78  * the historical limit of 20 open files (and the usage of descriptors by
  79  * shells).  If these descriptors are exhausted, a larger descriptor table
  80  * may be allocated, up to a process' resource limit; [XXXthe internal arrays
  81  * are then unusedXXX].  The initial expansion is set to NDEXTENT; each time
  82  * it runs out, it is doubled until the resource limit is reached. NDEXTENT
  83  * should be selected to be the biggest multiple of OFILESIZE (see below)
  84  * that will fit in a power-of-two sized piece of memory.
  85  */
  86 #define NDFILE          25              /* 125 bytes */
  87 #define NDEXTENT        50              /* 250 bytes in 256-byte alloc. */
  88
  89 struct klist;
  90
  91 struct filedesc {
  92         struct  fileproc **fd_ofiles;   /* file structures for open files */
  93         char    *fd_ofileflags;         /* per-process open file flags */
  94         struct  vnode *fd_cdir;         /* current directory */
  95         struct  vnode *fd_rdir;         /* root directory */
  96         int     fd_nfiles;              /* number of open files allocated */
  97         u_short fd_lastfile;            /* high-water mark of fd_ofiles */
  98         u_short fd_freefile;            /* approx. next free file */
  99         u_short fd_cmask;               /* mask for file creation */
 100         u_short fd_refcnt;              /* reference count */
 101
 102         int     fd_knlistsize;          /* size of knlist */
 103         struct  klist *fd_knlist;       /* list of attached knotes */
 104         u_long  fd_knhashmask;          /* size of knhash */
 105         struct  klist *fd_knhash;       /* hash table for attached knotes */
 106         int     fd_flags;
 107 };
 108
 109 /*
 110  * definitions for fd_flags;
 111  */
 112 #define FD_CHROOT       0x01    /* process was chrooted... keep track even */
 113                                 /* if we're force unmounted and unable to */
 114                                 /* take a vnode_ref on fd_rdir during a fork */
 115
 116 /*
 117  * Per-process open flags.
 118  */
 119 #define UF_EXCLOSE      0x01            /* auto-close on exec */
 120 #define UF_RESERVED     0x04            /* open pending / in progress */
 121 #define UF_CLOSING      0x08            /* close in progress */
 122
 123 /*
 124  * Storage required per open file descriptor.
 125  */
 126 #define OFILESIZE (sizeof(struct file *) + sizeof(char))
 127
 128 #ifdef KERNEL
 129 /*
 130  * Kernel global variables and routines.
 131  */
 132 extern int      dupfdopen(struct filedesc *fdp,
 133                                 int indx, int dfd, int mode, int error);
 134 extern int      fdalloc(struct proc *p, int want, int *result);
 135 extern void     fdrelse(struct proc *p, int fd);
 136 extern int      fdavail(struct proc *p, int n);
 137 #define         fdfile(p, fd)                                   \
 138                         (&(p)->p_fd->fd_ofiles[(fd)])
 139 #define         fdflags(p, fd)                                  \
 140                         (&(p)->p_fd->fd_ofileflags[(fd)])
 141 extern int      falloc(struct proc *p,
 142                                 struct fileproc **resultfp, int *resultfd);
 143 extern void     ffree(struct file *fp);
 144
 145 #ifdef __APPLE_API_PRIVATE
 146 extern struct   filedesc *fdcopy(struct proc *p);
 147 extern void     fdfree(struct proc *p);
 148 extern void     fdexec(struct proc *p);
 149 #endif /* __APPLE_API_PRIVATE */
 150
 151 #endif /* KERNEL */
 152
 153 #endif /* __APPLE_API_UNSTABLE */
 154
 155 #endif /* !_SYS_FILEDESC_H_ */