text: /*
   * Copyright (c) 2000-2012 Apple Computer, Inc. All rights reserved.
   *
   * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   * 
   * This file contains Original Code and/or Modifications of Original Code
   * as defined in and that are subject to the Apple Public Source License
   * Version 2.0 (the 'License'). You may not use this file except in
   * compliance with the License. The rights granted to you under the License
   * may not be used to create, or enable the creation or redistribution of,
   * unlawful or unlicensed copies of an Apple operating system, or to
   * circumvent, violate, or enable the circumvention or violation of, any
   * terms of an Apple operating system software license agreement.
   * 
   * Please obtain a copy of the License at
   * http://www.opensource.apple.com/apsl/ and read it before using this file.
   * 
   * The 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, QUIET ENJOYMENT OR NON-INFRINGEMENT.
   * Please see the License for the specific language governing rights and
   * limitations under the License.
   * 
   * @APPLE_OSREFERENCE_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_
  
  #include <sys/appleapiopts.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. */ 
  
  #ifdef BSD_KERNEL_PRIVATE
  
  #include <kern/locks.h>
  
  struct klist;
  struct kqlist;
  
  struct filedesc {
  	struct	fileproc **fd_ofiles;	/* file structures for open files */
  	lck_mtx_t fd_kqhashlock;        /* lock for dynamic kqueue hash */
  	u_long  fd_kqhashmask;          /* size of dynamic kqueue hash */
  	struct  kqlist *fd_kqhash;      /* hash table for dynamic kqueues */
  	struct  kqueue *fd_wqkqueue;    /* the workq kqueue */
  	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 */
  	int	fd_lastfile;		/* high-water mark of fd_ofiles */
  	int	fd_freefile;		/* approx. next free file */
  	u_short	fd_cmask;		/* mask for file creation */
          int	fd_flags;
  	int     fd_knlistsize;          /* size of knlist */
  	struct  klist *fd_knlist;       /* list of attached knotes */
  	u_long  fd_knhashmask;          /* size of knhash */
  	struct  klist *fd_knhash;       /* hash table for attached knotes */
  	lck_mtx_t fd_knhashlock;	/* lock for hash table for attached knotes */
  };
  
  /*
   * definitions for fd_flags;
   */
  #define	FD_CHROOT	0x01	/* process was chrooted... keep track even */
                                  /* if we're force unmounted and unable to */
                                  /* take a vnode_ref on fd_rdir during a fork */
  
  /*
   * Per-process open flags.
   */
  #define UF_EXCLOSE	0x01		/* auto-close on exec */
  #define UF_FORKCLOSE	0x02		/* auto-close on fork */
  #define UF_RESERVED	0x04		/* open pending / in progress */
  #define UF_CLOSING	0x08		/* close in progress */
  
  #ifdef KERNEL
  #define UF_RESVWAIT	0x10		/* close in progress */
  #define	UF_INHERIT	0x20		/* "inherit-on-exec" */
  
  #define UF_VALID_FLAGS	\
  	(UF_EXCLOSE | UF_FORKCLOSE | UF_RESERVED | UF_CLOSING |\
  	UF_RESVWAIT | UF_INHERIT)
  #endif /* KERNEL */
  
  /*
   * Storage required per open file descriptor.
   */
  #define OFILESIZE (sizeof(struct file *) + sizeof(char))
  
  #ifdef KERNEL
  /*
   * Kernel global variables and routines.
   */
  extern int	dupfdopen(struct filedesc *fdp,
  				int indx, int dfd, int mode, int error);
  extern int	fdalloc(proc_t p, int want, int *result);
  extern void	fdrelse(proc_t p, int fd);
  extern int	fdavail(proc_t p, int n);
  #define		fdfile(p, fd)					\
  			(&(p)->p_fd->fd_ofiles[(fd)])
  #define		fdflags(p, fd)					\
  			(&(p)->p_fd->fd_ofileflags[(fd)])
  
  /*
   * Accesor macros for fd flags
   */
  #define FDFLAGS_GET(p, fd) (*fdflags(p, fd) & (UF_EXCLOSE|UF_FORKCLOSE))
  #define FDFLAGS_SET(p, fd, bits) \
  	   (*fdflags(p, fd) |= ((bits) & (UF_EXCLOSE|UF_FORKCLOSE)))
  #define FDFLAGS_CLR(p, fd, bits) \
  	   (*fdflags(p, fd) &= ~((bits) & (UF_EXCLOSE|UF_FORKCLOSE)))
  
  extern int	falloc(proc_t p, struct fileproc **resultfp, int *resultfd, vfs_context_t ctx);
  
  #ifdef __APPLE_API_PRIVATE
  typedef struct fileproc *(*fp_allocfn_t)(void *);
  extern int	falloc_withalloc(proc_t p, struct fileproc **resultfp,
      int *resultfd, vfs_context_t ctx,
      fp_allocfn_t fp_zalloc, void *crarg);
  
  extern struct	filedesc *fdcopy(proc_t p, struct vnode *uth_cdir);
  extern void	fdfree(proc_t p);
  extern void	fdexec(proc_t p, short flags, int self_exec);
  #endif /* __APPLE_API_PRIVATE */
  
  #endif /* KERNEL */
  
  #endif /* BSD_KERNEL_PRIVATE */
  
  #endif /* !_SYS_FILEDESC_H_ */
  