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Diffstat (limited to '')
-rw-r--r-- | src/VBox/Runtime/common/misc/handletablectx.cpp | 329 |
1 files changed, 329 insertions, 0 deletions
diff --git a/src/VBox/Runtime/common/misc/handletablectx.cpp b/src/VBox/Runtime/common/misc/handletablectx.cpp new file mode 100644 index 00000000..6f08a166 --- /dev/null +++ b/src/VBox/Runtime/common/misc/handletablectx.cpp @@ -0,0 +1,329 @@ +/* $Id: handletablectx.cpp $ */ +/** @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/err.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) RTHandleTableAllocWithCtx(RTHANDLETABLE hHandleTable, void *pvObj, void *pvCtx, uint32_t *ph) +{ + PRTHANDLETABLEINT pThis; + int rc; + + /* validate the input */ + pThis = (PRTHANDLETABLEINT)hHandleTable; + AssertPtrReturn(pThis, VERR_INVALID_HANDLE); + AssertReturn(pThis->u32Magic == RTHANDLETABLE_MAGIC, VERR_INVALID_HANDLE); + AssertReturn(pThis->fFlags & RTHANDLETABLE_FLAGS_CONTEXT, VERR_INVALID_FUNCTION); + AssertReturn(!RTHT_IS_FREE(pvObj), VERR_INVALID_PARAMETER); + AssertPtrReturn(ph, VERR_INVALID_POINTER); + *ph = pThis->uBase - 1; + + /* + * Allocation loop. + */ + rtHandleTableLock(pThis); + + do + { + /* + * Try grab a free entry from the head of the free list. + */ + uint32_t i = pThis->iFreeHead; + if (i != NIL_RTHT_INDEX) + { + PRTHTENTRYCTX pEntry; + PRTHTENTRYFREE pFree = (PRTHTENTRYFREE)rtHandleTableLookupWithCtxIdx(pThis, i); + Assert(pFree); + if (i == pThis->iFreeTail) + pThis->iFreeTail = pThis->iFreeHead = NIL_RTHT_INDEX; + else + pThis->iFreeHead = RTHT_GET_FREE_IDX(pFree); + pThis->cCurAllocated++; + Assert(pThis->cCurAllocated <= pThis->cCur); + + /* + * Setup the entry and return. + */ + pEntry = (PRTHTENTRYCTX)pFree; + pEntry->pvObj = pvObj; + pEntry->pvCtx = pvCtx; + *ph = i + pThis->uBase; + rc = VINF_SUCCESS; + } + /* + * Must expand the handle table, unless it's full. + */ + else if (pThis->cCur >= pThis->cMax) + { + rc = VERR_NO_MORE_HANDLES; + Assert(pThis->cCur == pThis->cCurAllocated); + } + else + { + void **papvLevel1; + uint32_t iLevel1New; + PRTHTENTRYCTX paTable; + + /* + * Do we have to expand the 1st level table too? + */ + uint32_t const iLevel1 = pThis->cCur / RTHT_LEVEL2_ENTRIES; + uint32_t cLevel1 = iLevel1 >= pThis->cLevel1 + ? pThis->cLevel1 + PAGE_SIZE / sizeof(void *) + : 0; + if (cLevel1 > pThis->cMax / RTHT_LEVEL2_ENTRIES) + cLevel1 = pThis->cMax / RTHT_LEVEL2_ENTRIES; + Assert(!cLevel1 || pThis->cMax / RTHT_LEVEL2_ENTRIES >= RTHT_LEVEL1_DYN_ALLOC_THRESHOLD); + + /* leave the lock (never do fancy stuff from behind a spinlock). */ + rtHandleTableUnlock(pThis); + + /* + * Do the allocation(s). + */ + rc = VERR_TRY_AGAIN; + papvLevel1 = NULL; + if (cLevel1) + { + papvLevel1 = (void **)RTMemAlloc(sizeof(void *) * cLevel1); + if (!papvLevel1) + return VERR_NO_MEMORY; + } + + paTable = (PRTHTENTRYCTX)RTMemAlloc(sizeof(*paTable) * RTHT_LEVEL2_ENTRIES); + if (!paTable) + { + RTMemFree(papvLevel1); + return VERR_NO_MEMORY; + } + + /* re-enter the lock. */ + rtHandleTableLock(pThis); + + /* + * Insert the new bits, but be a bit careful as someone might have + * raced us expanding the table. + */ + /* deal with the 1st level lookup expansion first */ + if (cLevel1) + { + Assert(papvLevel1); + if (cLevel1 > pThis->cLevel1) + { + void **papvTmp; + + /* Replace the 1st level table. */ + memcpy(papvLevel1, pThis->papvLevel1, sizeof(void *) * pThis->cLevel1); + memset(&papvLevel1[pThis->cLevel1], 0, sizeof(void *) * (cLevel1 - pThis->cLevel1)); + pThis->cLevel1 = cLevel1; + papvTmp = pThis->papvLevel1; + pThis->papvLevel1 = papvLevel1; + papvLevel1 = papvTmp; + } + + /* free the obsolete one (outside the lock of course) */ + rtHandleTableUnlock(pThis); + RTMemFree(papvLevel1); + rtHandleTableLock(pThis); + } + + /* insert the table we allocated. */ + iLevel1New = pThis->cCur / RTHT_LEVEL2_ENTRIES; + if ( iLevel1New < pThis->cLevel1 + && pThis->cCur < pThis->cMax) + { + pThis->papvLevel1[iLevel1New] = paTable; + + /* link all entries into a free list. */ + Assert(!(pThis->cCur % RTHT_LEVEL2_ENTRIES)); + for (i = 0; i < RTHT_LEVEL2_ENTRIES - 1; i++) + { + RTHT_SET_FREE_IDX((PRTHTENTRYFREE)&paTable[i], i + 1 + pThis->cCur); + paTable[i].pvCtx = (void *)~(uintptr_t)7; + } + RTHT_SET_FREE_IDX((PRTHTENTRYFREE)&paTable[RTHT_LEVEL2_ENTRIES - 1], NIL_RTHT_INDEX); + paTable[RTHT_LEVEL2_ENTRIES - 1].pvCtx = (void *)~(uintptr_t)7; + + /* join the free list with the other. */ + if (pThis->iFreeTail == NIL_RTHT_INDEX) + pThis->iFreeHead = pThis->cCur; + else + { + PRTHTENTRYFREE pPrev = (PRTHTENTRYFREE)rtHandleTableLookupWithCtxIdx(pThis, pThis->iFreeTail); + Assert(pPrev); + RTHT_SET_FREE_IDX(pPrev, pThis->cCur); + } + pThis->iFreeTail = pThis->cCur + RTHT_LEVEL2_ENTRIES - 1; + + pThis->cCur += RTHT_LEVEL2_ENTRIES; + } + else + { + /* free the table (raced someone, and we lost). */ + rtHandleTableUnlock(pThis); + RTMemFree(paTable); + rtHandleTableLock(pThis); + } + + rc = VERR_TRY_AGAIN; + } + } while (rc == VERR_TRY_AGAIN); + + rtHandleTableUnlock(pThis); + + return rc; +} +RT_EXPORT_SYMBOL(RTHandleTableAllocWithCtx); + + +RTDECL(void *) RTHandleTableLookupWithCtx(RTHANDLETABLE hHandleTable, uint32_t h, void *pvCtx) +{ + void *pvObj = NULL; + PRTHTENTRYCTX pEntry; + PRTHANDLETABLEINT pThis; + + /* validate the input */ + pThis = (PRTHANDLETABLEINT)hHandleTable; + AssertPtrReturn(pThis, NULL); + AssertReturn(pThis->u32Magic == RTHANDLETABLE_MAGIC, NULL); + AssertReturn(pThis->fFlags & RTHANDLETABLE_FLAGS_CONTEXT, NULL); + + + /* acquire the lock */ + rtHandleTableLock(pThis); + + /* + * Perform the lookup and retaining. + */ + pEntry = rtHandleTableLookupWithCtx(pThis, h); + if (pEntry && pEntry->pvCtx == pvCtx) + { + pvObj = pEntry->pvObj; + if (!RTHT_IS_FREE(pvObj)) + { + if (pThis->pfnRetain) + { + int rc = pThis->pfnRetain(hHandleTable, pEntry->pvObj, pvCtx, pThis->pvRetainUser); + if (RT_FAILURE(rc)) + pvObj = NULL; + } + } + else + pvObj = NULL; + } + + /* release the lock */ + rtHandleTableUnlock(pThis); + return pvObj; +} +RT_EXPORT_SYMBOL(RTHandleTableLookupWithCtx); + + +RTDECL(void *) RTHandleTableFreeWithCtx(RTHANDLETABLE hHandleTable, uint32_t h, void *pvCtx) +{ + void *pvObj = NULL; + PRTHTENTRYCTX pEntry; + PRTHANDLETABLEINT pThis; + + /* validate the input */ + pThis = (PRTHANDLETABLEINT)hHandleTable; + AssertPtrReturn(pThis, NULL); + AssertReturn(pThis->u32Magic == RTHANDLETABLE_MAGIC, NULL); + AssertReturn(pThis->fFlags & RTHANDLETABLE_FLAGS_CONTEXT, NULL); + + + /* acquire the lock */ + rtHandleTableLock(pThis); + + /* + * Perform the lookup and retaining. + */ + pEntry = rtHandleTableLookupWithCtx(pThis, h); + if (pEntry && pEntry->pvCtx == pvCtx) + { + pvObj = pEntry->pvObj; + if (!RTHT_IS_FREE(pvObj)) + { + if (pThis->pfnRetain) + { + int rc = pThis->pfnRetain(hHandleTable, pEntry->pvObj, pvCtx, pThis->pvRetainUser); + if (RT_FAILURE(rc)) + pvObj = NULL; + } + + /* + * Link it into the free list. + */ + if (pvObj) + { + PRTHTENTRYFREE pFree; + uint32_t i; + + pEntry->pvCtx = (void *)~(uintptr_t)7; + + pFree = (PRTHTENTRYFREE)pEntry; + RTHT_SET_FREE_IDX(pFree, NIL_RTHT_INDEX); + + i = h - pThis->uBase; + if (pThis->iFreeTail == NIL_RTHT_INDEX) + pThis->iFreeHead = pThis->iFreeTail = i; + else + { + PRTHTENTRYFREE pPrev = (PRTHTENTRYFREE)rtHandleTableLookupWithCtxIdx(pThis, pThis->iFreeTail); + Assert(pPrev); + RTHT_SET_FREE_IDX(pPrev, i); + pThis->iFreeTail = i; + } + + Assert(pThis->cCurAllocated > 0); + pThis->cCurAllocated--; + } + } + else + pvObj = NULL; + } + + /* release the lock */ + rtHandleTableUnlock(pThis); + return pvObj; +} +RT_EXPORT_SYMBOL(RTHandleTableFreeWithCtx); + |