Current File : //usr/src/vboxhost-6.0.14/vboxdrv/common/misc/handletable.c
/* $Id: handletable.cpp 127855 2019-01-01 01:45:53Z bird $ */
/** @file
* IPRT - Handle Tables.
*/
/*
* Copyright (C) 2008-2019 Oracle Corporation
*
* This file is part of VirtualBox Open Source Edition (OSE), as
* available from http://www.virtualbox.org. This file is free software;
* you can redistribute it and/or modify it under the terms of the GNU
* 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.
*/
/*********************************************************************************************************************************
* Header Files *
*********************************************************************************************************************************/
#include <iprt/handletable.h>
#include "internal/iprt.h"
#include <iprt/mem.h>
#include <iprt/spinlock.h>
#include <iprt/errcore.h>
#include <iprt/assert.h>
#include <iprt/param.h>
#include <iprt/string.h>
#include <iprt/asm.h>
#include "internal/magics.h"
#include "handletable.h"
RTDECL(int) RTHandleTableCreateEx(PRTHANDLETABLE phHandleTable, uint32_t fFlags, uint32_t uBase, uint32_t cMax,
PFNRTHANDLETABLERETAIN pfnRetain, void *pvUser)
{
PRTHANDLETABLEINT pThis;
uint32_t cLevel1;
size_t cb;
/*
* Validate input.
*/
AssertPtrReturn(phHandleTable, VERR_INVALID_POINTER);
*phHandleTable = NIL_RTHANDLETABLE;
AssertPtrNullReturn(pfnRetain, VERR_INVALID_POINTER);
AssertReturn(!(fFlags & ~RTHANDLETABLE_FLAGS_MASK), VERR_INVALID_PARAMETER);
AssertReturn(RT_BOOL(fFlags & RTHANDLETABLE_FLAGS_LOCKED) + RT_BOOL(fFlags & RTHANDLETABLE_FLAGS_LOCKED_IRQ_SAFE) < 2,
VERR_INVALID_PARAMETER);
AssertReturn(cMax > 0, VERR_INVALID_PARAMETER);
AssertReturn(UINT32_MAX - cMax >= uBase, VERR_INVALID_PARAMETER);
/*
* Adjust the cMax value so it is a multiple of the 2nd level tables.
*/
if (cMax >= UINT32_MAX - RTHT_LEVEL2_ENTRIES)
cMax = UINT32_MAX - RTHT_LEVEL2_ENTRIES + 1;
cMax = ((cMax + RTHT_LEVEL2_ENTRIES - 1) / RTHT_LEVEL2_ENTRIES) * RTHT_LEVEL2_ENTRIES;
cLevel1 = cMax / RTHT_LEVEL2_ENTRIES;
Assert(cLevel1 * RTHT_LEVEL2_ENTRIES == cMax);
/*
* Allocate the structure, include the 1st level lookup table
* if it's below the threshold size.
*/
cb = sizeof(RTHANDLETABLEINT);
if (cLevel1 < RTHT_LEVEL1_DYN_ALLOC_THRESHOLD)
cb = RT_ALIGN(cb, sizeof(void *)) + cLevel1 * sizeof(void *);
pThis = (PRTHANDLETABLEINT)RTMemAllocZ(cb);
if (!pThis)
return VERR_NO_MEMORY;
/*
* Initialize it.
*/
pThis->u32Magic = RTHANDLETABLE_MAGIC;
pThis->fFlags = fFlags;
pThis->uBase = uBase;
pThis->cCur = 0;
pThis->hSpinlock = NIL_RTSPINLOCK;
if (cLevel1 < RTHT_LEVEL1_DYN_ALLOC_THRESHOLD)
pThis->papvLevel1 = (void **)((uint8_t *)pThis + RT_ALIGN(sizeof(*pThis), sizeof(void *)));
else
pThis->papvLevel1 = NULL;
pThis->pfnRetain = pfnRetain;
pThis->pvRetainUser = pvUser;
pThis->cMax = cMax;
pThis->cCurAllocated = 0;
pThis->cLevel1 = cLevel1 < RTHT_LEVEL1_DYN_ALLOC_THRESHOLD ? cLevel1 : 0;
pThis->iFreeHead = NIL_RTHT_INDEX;
pThis->iFreeTail = NIL_RTHT_INDEX;
if (fFlags & (RTHANDLETABLE_FLAGS_LOCKED | RTHANDLETABLE_FLAGS_LOCKED_IRQ_SAFE))
{
int rc;
if (fFlags & RTHANDLETABLE_FLAGS_LOCKED_IRQ_SAFE)
rc = RTSpinlockCreate(&pThis->hSpinlock, RTSPINLOCK_FLAGS_INTERRUPT_SAFE, "RTHandleTableCreateEx");
else
rc = RTSpinlockCreate(&pThis->hSpinlock, RTSPINLOCK_FLAGS_INTERRUPT_UNSAFE, "RTHandleTableCreateEx");
if (RT_FAILURE(rc))
{
RTMemFree(pThis);
return rc;
}
}
*phHandleTable = pThis;
return VINF_SUCCESS;
}
RT_EXPORT_SYMBOL(RTHandleTableCreateEx);
RTDECL(int) RTHandleTableCreate(PRTHANDLETABLE phHandleTable)
{
return RTHandleTableCreateEx(phHandleTable, RTHANDLETABLE_FLAGS_LOCKED, 1, 65534, NULL, NULL);
}
RT_EXPORT_SYMBOL(RTHandleTableCreate);
RTDECL(int) RTHandleTableDestroy(RTHANDLETABLE hHandleTable, PFNRTHANDLETABLEDELETE pfnDelete, void *pvUser)
{
PRTHANDLETABLEINT pThis;
uint32_t i1;
uint32_t i;
/*
* Validate input, quietly ignore the NIL handle.
*/
if (hHandleTable == NIL_RTHANDLETABLE)
return VINF_SUCCESS;
pThis = (PRTHANDLETABLEINT)hHandleTable;
AssertPtrReturn(pThis, VERR_INVALID_HANDLE);
AssertReturn(pThis->u32Magic == RTHANDLETABLE_MAGIC, VERR_INVALID_HANDLE);
AssertPtrNullReturn(pfnDelete, VERR_INVALID_POINTER);
/*
* Mark the thing as invalid / deleted.
* Then kill the lock.
*/
rtHandleTableLock(pThis);
ASMAtomicWriteU32(&pThis->u32Magic, ~RTHANDLETABLE_MAGIC);
rtHandleTableUnlock(pThis);
if (pThis->hSpinlock != NIL_RTSPINLOCK)
{
rtHandleTableLock(pThis);
rtHandleTableUnlock(pThis);
RTSpinlockDestroy(pThis->hSpinlock);
pThis->hSpinlock = NIL_RTSPINLOCK;
}
if (pfnDelete)
{
/*
* Walk all the tables looking for used handles.
*/
uint32_t cLeft = pThis->cCurAllocated;
if (pThis->fFlags & RTHANDLETABLE_FLAGS_CONTEXT)
{
for (i1 = 0; cLeft > 0 && i1 < pThis->cLevel1; i1++)
{
PRTHTENTRYCTX paTable = (PRTHTENTRYCTX)pThis->papvLevel1[i1];
if (paTable)
for (i = 0; i < RTHT_LEVEL2_ENTRIES; i++)
if (!RTHT_IS_FREE(paTable[i].pvObj))
{
pfnDelete(hHandleTable, pThis->uBase + i + i1 * RTHT_LEVEL2_ENTRIES,
paTable[i].pvObj, paTable[i].pvCtx, pvUser);
Assert(cLeft > 0);
cLeft--;
}
}
}
else
{
for (i1 = 0; cLeft > 0 && i1 < pThis->cLevel1; i1++)
{
PRTHTENTRY paTable = (PRTHTENTRY)pThis->papvLevel1[i1];
if (paTable)
for (i = 0; i < RTHT_LEVEL2_ENTRIES; i++)
if (!RTHT_IS_FREE(paTable[i].pvObj))
{
pfnDelete(hHandleTable, pThis->uBase + i + i1 * RTHT_LEVEL2_ENTRIES,
paTable[i].pvObj, NULL, pvUser);
Assert(cLeft > 0);
cLeft--;
}
}
}
Assert(!cLeft);
}
/*
* Free the memory.
*/
for (i1 = 0; i1 < pThis->cLevel1; i1++)
if (pThis->papvLevel1[i1])
{
RTMemFree(pThis->papvLevel1[i1]);
pThis->papvLevel1[i1] = NULL;
}
if (pThis->cMax / RTHT_LEVEL2_ENTRIES >= RTHT_LEVEL1_DYN_ALLOC_THRESHOLD)
RTMemFree(pThis->papvLevel1);
RTMemFree(pThis);
return VINF_SUCCESS;
}
RT_EXPORT_SYMBOL(RTHandleTableDestroy);
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