Source to osfmk/ipc/ipc_entry.h
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/*
* @OSF_COPYRIGHT@
*/
/*
* Mach Operating System
* Copyright (c) 1991,1990,1989 Carnegie Mellon University
* All Rights Reserved.
*
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* documentation is hereby granted, provided that both the copyright
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*
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*/
/*
*/
/*
* 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_types.h>
/*
* Spaces hold capabilities for ipc_object_t's.
* 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 natural_t ipc_entry_bits_t;
typedef ipc_table_elems_t ipc_entry_num_t; /* number of entries */
typedef struct ipc_entry {
struct ipc_object *ie_object;
ipc_entry_bits_t ie_bits;
union {
mach_port_index_t next; /* next in freelist, or... */
ipc_table_index_t request; /* dead name request notify */
} 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_COLLISION 0x00800000 /* 1 bit for collisions */
#ifndef NO_PORT_GEN
#define IE_BITS_GEN_MASK 0xff000000 /* 8 bits for generation */
#define IE_BITS_GEN(bits) ((bits) & IE_BITS_GEN_MASK)
#define IE_BITS_GEN_ONE 0x04000000 /* low bit of generation */
#define IE_BITS_NEW_GEN(old) (((old) + IE_BITS_GEN_ONE) & IE_BITS_GEN_MASK)
#else
#define IE_BITS_GEN_MASK 0
#define IE_BITS_GEN(bits) 0
#define IE_BITS_GEN_ONE 0
#define IE_BITS_NEW_GEN(old) (old)
#endif /* !USE_PORT_GEN */
#define IE_BITS_RIGHT_MASK 0x007fffff /* relevant to the right */
typedef struct ipc_tree_entry {
struct ipc_entry ite_entry;
mach_port_name_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))
/*
* Exported interfaces
*/
/* Search for entry in a space by name */
extern ipc_entry_t ipc_entry_lookup(
ipc_space_t space,
mach_port_name_t name);
/* Allocate an entry in a space */
extern kern_return_t ipc_entry_get(
ipc_space_t space,
mach_port_name_t *namep,
ipc_entry_t *entryp);
/* Allocate an entry in a space, growing the space if necessary */
extern kern_return_t ipc_entry_alloc(
ipc_space_t space,
mach_port_name_t *namep,
ipc_entry_t *entryp);
/* Allocate/find an entry in a space with a specific name */
extern kern_return_t ipc_entry_alloc_name(
ipc_space_t space,
mach_port_name_t name,
ipc_entry_t *entryp);
/* Deallocate an entry from a space */
extern void ipc_entry_dealloc(
ipc_space_t space,
mach_port_name_t name,
ipc_entry_t entry);
/* Grow the table in a space */
extern kern_return_t ipc_entry_grow_table(
ipc_space_t space,
int target_size);
#endif /* _IPC_IPC_ENTRY_H_ */