handletable.h revision f0ed7ab5e7f8d2f73b5aa08e46eb3a04cbb31cb2
/* $Id$ */
/** @file
* IPRT - Handle Tables, internal header.
*/
/*
* Copyright (C) 2008 Oracle Corporation
*
* This file is part of VirtualBox Open Source Edition (OSE), as
* available from http://www.virtualbox.org. This file is free software;
* General Public License (GPL) as published by the Free Software
* Foundation, in version 2 as it comes in the "COPYING" file of the
* VirtualBox OSE distribution. VirtualBox OSE is distributed in the
* hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
*
* The contents of this file may alternatively be used under the terms
* of the Common Development and Distribution License Version 1.0
* (CDDL) only, as it comes in the "COPYING.CDDL" file of the
* VirtualBox OSE distribution, in which case the provisions of the
* CDDL are applicable instead of those of the GPL.
*
* You may elect to license modified versions of this file under the
* terms and conditions of either the GPL or the CDDL or both.
*/
/*******************************************************************************
* Defined Constants And Macros *
*******************************************************************************/
/** The number of entries in the 2nd level lookup table. */
#define RTHT_LEVEL2_ENTRIES 2048
/** The number of (max) 1st level entries requiring dynamic allocation of the
* 1st level table. If the max number is below this threshold, the 1st level
* table will be allocated as part of the handle table structure. */
#define RTHT_LEVEL1_DYN_ALLOC_THRESHOLD 256
/** Checks whether a object pointer is really a free entry or not. */
/** Sets RTHTENTRYFREE::iNext. */
do { \
} while (0)
/** Gets the index part of RTHTENTRYFREE::iNext. */
/** @def NIL_RTHT_INDEX
* The NIL handle index for use in the free list. (The difference between
* 32-bit and 64-bit hosts here comes down to the shifting performed for
* RTHTENTRYFREE::iNext.) */
#if ARCH_BITS == 32
#else
# error "Missing or unsupported ARCH_BITS."
#endif
/*******************************************************************************
* Structures and Typedefs *
*******************************************************************************/
/**
* Handle table entry, simple variant.
*/
typedef struct RTHTENTRY
{
/** The object. */
void *pvObj;
} RTHTENTRY;
/** Pointer to a handle table entry, simple variant. */
typedef RTHTENTRY *PRTHTENTRY;
/**
* Handle table entry, context variant.
*/
typedef struct RTHTENTRYCTX
{
/** The object. */
void *pvObj;
/** The context. */
void *pvCtx;
} RTHTENTRYCTX;
/** Pointer to a handle table entry, context variant. */
typedef RTHTENTRYCTX *PRTHTENTRYCTX;
/**
* Free handle table entry, shared by all variants.
*/
typedef struct RTHTENTRYFREE
{
/** The index of the next handle, special format.
* In order to distinguish free and used handle table entries we exploit
* the heap alignment and use the lower two bits to do this. Used entries
* will have these bits set to 0, while free entries will have tem set
* to 3. Use the RTHT_GET_FREE_IDX and RTHT_SET_FREE_IDX macros to access
* this field. */
/** Pointer to a free handle table entry. */
typedef RTHTENTRYFREE *PRTHTENTRYFREE;
/**
* Internal handle table structure.
*/
typedef struct RTHANDLETABLEINT
{
/** Magic value (RTHANDLETABLE_MAGIC). */
/** The handle table flags specified to RTHandleTableCreateEx. */
/** The base handle value (i.e. the first handle). */
/** The current number of handle table entries. */
/** The spinlock handle (NIL if RTHANDLETABLE_FLAGS_LOCKED wasn't used). */
/** The level one lookup table. */
void **papvLevel1;
/** The retainer callback. Can be NULL. */
/** The user argument to the retainer. */
void *pvRetainUser;
/** The max number of handles. */
/** The number of handles currently allocated. (for optimizing destruction) */
/** The current number of 1st level entries. */
/** Head of the list of free handle entires (index). */
/** Tail of the list of free handle entires (index). */
/** Pointer to an handle table structure. */
typedef RTHANDLETABLEINT *PRTHANDLETABLEINT;
/**
* Looks up a simple index.
*
* @returns Pointer to the handle table entry on success, NULL on failure.
* @param pThis The handle table structure.
* @param i The index to look up.
*/
{
{
if (paTable)
return &paTable[i % RTHT_LEVEL2_ENTRIES];
}
return NULL;
}
/**
* Looks up a simple handle.
*
* @returns Pointer to the handle table entry on success, NULL on failure.
* @param pThis The handle table structure.
* @param h The handle to look up.
*/
{
}
/**
* Looks up a context index.
*
* @returns Pointer to the handle table entry on success, NULL on failure.
* @param pThis The handle table structure.
* @param i The index to look up.
*/
{
{
if (paTable)
return &paTable[i % RTHT_LEVEL2_ENTRIES];
}
return NULL;
}
/**
* Looks up a context handle.
*
* @returns Pointer to the handle table entry on success, NULL on failure.
* @param pThis The handle table structure.
* @param h The handle to look up.
*/
{
}
/**
* Locks the handle table.
*
* @param pThis The handle table structure.
*/
{
{
}
}
/**
* Locks the handle table.
*
* @param pThis The handle table structure.
*/
{
}