reactos/drivers/lib/oskittcp/include/freebsd/src/sys/sys/filedesc.h

   1 /*
   2  * Copyright (c) 1990, 1993
   3  *      The Regents of the University of California.  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, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  *
  33  *      @(#)filedesc.h  8.1 (Berkeley) 6/2/93
  34  */
  35
  36 #ifndef _SYS_FILEDESC_H_
  37 #define _SYS_FILEDESC_H_
  38
  39 /*
  40  * This structure is used for the management of descriptors.  It may be
  41  * shared by multiple processes.
  42  *
  43  * A process is initially started out with NDFILE descriptors stored within
  44  * this structure, selected to be enough for typical applications based on
  45  * the historical limit of 20 open files (and the usage of descriptors by
  46  * shells).  If these descriptors are exhausted, a larger descriptor table
  47  * may be allocated, up to a process' resource limit; the internal arrays
  48  * are then unused.  The initial expansion is set to NDEXTENT; each time
  49  * it runs out, it is doubled until the resource limit is reached. NDEXTENT
  50  * should be selected to be the biggest multiple of OFILESIZE (see below)
  51  * that will fit in a power-of-two sized piece of memory.
  52  */
  53 #define NDFILE          20
  54 #define NDEXTENT        50              /* 250 bytes in 256-byte alloc. */
  55
  56 struct filedesc {
  57         struct  file **fd_ofiles;       /* file structures for open files */
  58         char    *fd_ofileflags;         /* per-process open file flags */
  59         struct  vnode *fd_cdir;         /* current directory */
  60         struct  vnode *fd_rdir;         /* root directory */
  61         int     fd_nfiles;              /* number of open files allocated */
  62         u_short fd_lastfile;            /* high-water mark of fd_ofiles */
  63         u_short fd_freefile;            /* approx. next free file */
  64         u_short fd_cmask;               /* mask for file creation */
  65         u_short fd_refcnt;              /* reference count */
  66 };
  67
  68 /*
  69  * Basic allocation of descriptors:
  70  * one of the above, plus arrays for NDFILE descriptors.
  71  */
  72 struct filedesc0 {
  73         struct  filedesc fd_fd;
  74         /*
  75          * These arrays are used when the number of open files is
  76          * <= NDFILE, and are then pointed to by the pointers above.
  77          */
  78         struct  file *fd_dfiles[NDFILE];
  79         char    fd_dfileflags[NDFILE];
  80 };
  81
  82 /*
  83  * Per-process open flags.
  84  */
  85 #define UF_EXCLOSE      0x01            /* auto-close on exec */
  86 #define UF_MAPPED       0x02            /* mapped from device */
  87
  88 /*
  89  * Storage required per open file descriptor.
  90  */
  91 #define OFILESIZE (sizeof(struct file *) + sizeof(char))
  92
  93 #ifdef KERNEL
  94 /*
  95  * Kernel global variables and routines.
  96  */
  97 int     dupfdopen __P((struct filedesc *, int, int, int, int));
  98 int     fdalloc __P((struct proc *p, int want, int *result));
  99 int     fdavail __P((struct proc *p, int n));
 100 int     falloc __P((struct proc *p, struct file **resultfp, int *resultfd));
 101 void    ffree __P((struct file *));
 102 struct  filedesc *fdcopy __P((struct proc *p));
 103 void    fdfree __P((struct proc *p));
 104 int     closef __P((struct file *fp,struct proc *p));
 105 void    fdcloseexec __P((struct proc *p));
 106 #endif
 107
 108 #endif