FreeBSD/Linux Kernel Cross Reference
sys/ipc/ipc_entry.h

     /* 
      * Mach Operating System
      * Copyright (c) 1991,1990,1989 Carnegie Mellon University
      * All Rights Reserved.
      * 
      * Permission to use, copy, modify and distribute this software and its
      * documentation is hereby granted, provided that both the copyright
      * notice and this permission notice appear in all copies of the
      * software, derivative works or modified versions, and any portions
     * thereof, and that both notices appear in supporting documentation.
     * 
     * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
     * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
     * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
     * 
     * Carnegie Mellon requests users of this software to return to
     * 
     *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
     *  School of Computer Science
     *  Carnegie Mellon University
     *  Pittsburgh PA 15213-3890
     * 
     * any improvements or extensions that they make and grant Carnegie Mellon
     * the rights to redistribute these changes.
     */
    /*
     * HISTORY
     * $Log:        ipc_entry.h,v $
     * Revision 2.6  92/05/21  17:10:01  jfriedl
     *      Appended 'U' to long constants that would otherwise be signed.
     *      [92/05/16            jfriedl]
     * 
     * Revision 2.5  91/05/14  16:31:54  mrt
     *      Correcting copyright
     * 
     * Revision 2.4  91/02/05  17:21:24  mrt
     *      Changed to new Mach copyright
     *      [91/02/01  15:44:29  mrt]
     * 
     * Revision 2.3  91/01/08  15:13:06  rpd
     *      Removed MACH_IPC_GENNOS, IE_BITS_UNUSEDC, IE_BITS_UNUSEDG.
     *      [90/11/08            rpd]
     * 
     * Revision 2.2  90/06/02  14:49:41  rpd
     *      Created for new IPC.
     *      [90/03/26  20:54:40  rpd]
     * 
     */
    /*
     *      File:   ipc/ipc_entry.h
     *      Author: Rich Draves
     *      Date:   1989
     *
     *      Definitions for translation entries, which represent
     *      tasks' capabilities for ports and port sets.
     */
    
    #ifndef _IPC_IPC_ENTRY_H_
    #define _IPC_IPC_ENTRY_H_
    
    #include <mach/port.h>
    #include <mach/kern_return.h>
    #include <kern/zalloc.h>
    #include <ipc/port.h>
    #include <ipc/ipc_table.h>
    #include <ipc/ipc_port.h>
    
    /*
     *      Spaces hold capabilities for ipc_object_t's (ports and port sets).
     *      Each ipc_entry_t records a capability.  Most capabilities have
     *      small names, and the entries are elements of a table.
     *      Capabilities can have large names, and a splay tree holds
     *      those entries.  The cutoff point between the table and the tree
     *      is adjusted dynamically to minimize memory consumption.
     *
     *      The ie_index field of entries in the table implements
     *      a ordered hash table with open addressing and linear probing.
     *      This hash table converts (space, object) -> name.
     *      It is used independently of the other fields.
     *
     *      Free (unallocated) entries in the table have null ie_object
     *      fields.  The ie_bits field is zero except for IE_BITS_GEN.
     *      The ie_next (ie_request) field links free entries into a free list.
     *
     *      The first entry in the table (index 0) is always free.
     *      It is used as the head of the free list.
     */
    
    typedef unsigned int ipc_entry_bits_t;
    typedef ipc_table_elems_t ipc_entry_num_t;      /* number of entries */
    
    typedef struct ipc_entry {
            ipc_entry_bits_t ie_bits;
            struct ipc_object *ie_object;
            union {
                    mach_port_index_t next;
                    ipc_port_request_index_t request;
            } index;
            union {
                   mach_port_index_t table;
                   struct ipc_tree_entry *tree;
           } hash;
   } *ipc_entry_t;
   
   #define IE_NULL         ((ipc_entry_t) 0)
   
   #define ie_request      index.request
   #define ie_next         index.next
   #define ie_index        hash.table
   
   #define IE_BITS_UREFS_MASK      0x0000ffff      /* 16 bits of user-reference */
   #define IE_BITS_UREFS(bits)     ((bits) & IE_BITS_UREFS_MASK)
   
   #define IE_BITS_TYPE_MASK       0x001f0000      /* 5 bits of capability type */
   #define IE_BITS_TYPE(bits)      ((bits) & IE_BITS_TYPE_MASK)
   
   #define IE_BITS_MAREQUEST       0x00200000      /* 1 bit for msg-accepted */
   
   #define IE_BITS_COMPAT          0x00400000      /* 1 bit for compatibility */
   
   #define IE_BITS_COLLISION       0x00800000      /* 1 bit for collisions */
   #define IE_BITS_GEN_MASK        0xff000000U     /* 8 bits for generation */
   #define IE_BITS_GEN(bits)       ((bits) & IE_BITS_GEN_MASK)
   #define IE_BITS_GEN_ONE         0x01000000      /* low bit of generation */
   #define IE_BITS_RIGHT_MASK      0x007fffff      /* relevant to the right */
   
   
   typedef struct ipc_tree_entry {
           struct ipc_entry ite_entry;
           mach_port_t ite_name;
           struct ipc_space *ite_space;
           struct ipc_tree_entry *ite_lchild;
           struct ipc_tree_entry *ite_rchild;
   } *ipc_tree_entry_t;
   
   #define ITE_NULL        ((ipc_tree_entry_t) 0)
   
   #define ite_bits        ite_entry.ie_bits
   #define ite_object      ite_entry.ie_object
   #define ite_request     ite_entry.ie_request
   #define ite_next        ite_entry.hash.tree
   
   extern zone_t ipc_tree_entry_zone;
   
   #define ite_alloc()     ((ipc_tree_entry_t) zalloc(ipc_tree_entry_zone))
   #define ite_free(ite)   zfree(ipc_tree_entry_zone, (vm_offset_t) (ite))
   
   
   extern ipc_entry_t
   ipc_entry_lookup(/* ipc_space_t space, mach_port_t name */);
   
   extern kern_return_t
   ipc_entry_get(/* ipc_space_t space,
                    mach_port_t *namep, ipc_entry_t *entryp */);
   
   extern kern_return_t
   ipc_entry_alloc(/* ipc_space_t space,
                      mach_port_t *namep, ipc_entry_t *entryp */);
   
   extern kern_return_t
   ipc_entry_alloc_name(/* ipc_space_t space, mach_port_t name,
                           ipc_entry_t *entryp */);
   
   extern void
   ipc_entry_dealloc(/* ipc_space_t space, mach_port_t name,
                        ipc_entry_t entry */);
   
   extern kern_return_t
   ipc_entry_grow_table(/* ipc_space_t space */);
   
   #endif  _IPC_IPC_ENTRY_H_

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