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/* $Id: nocrt-per-thread-2.cpp $ */
/** @file
* IPRT - No-Crt - Per Thread Data, Managment code
*/
/*
* Copyright (C) 2006-2023 Oracle and/or its affiliates.
*
* This file is part of VirtualBox base platform packages, as
* available from https://www.virtualbox.org.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation, in version 3 of the
* License.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <https://www.gnu.org/licenses>.
*
* The contents of this file may alternatively be used under the terms
* of the Common Development and Distribution License Version 1.0
* (CDDL), a copy of it is provided in the "COPYING.CDDL" file included
* in the VirtualBox 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.
*
* SPDX-License-Identifier: GPL-3.0-only OR CDDL-1.0
*/
/*********************************************************************************************************************************
* Defined Constants And Macros *
*********************************************************************************************************************************/
#include "internal/nocrt.h"
#include <iprt/asm.h>
#include <iprt/critsect.h>
#include <iprt/errcore.h>
#include <iprt/mem.h>
#include <iprt/once.h>
#include <iprt/thread.h>
/*********************************************************************************************************************************
* Global Variables *
*********************************************************************************************************************************/
/** Init/term once state. */
static RTONCE g_NoCrtPerThreadOnce = RTONCE_INITIALIZER;
/** List of heap allocations (PRTNOCRTTHREADDATA). */
static RTLISTANCHOR g_NoCrtPerThreadHeapList;
/** Critical section protecting g_NoCrtPerThreadHeapList. */
static RTCRITSECT g_NoCrtPerThreadCritSect;
/** Allocation bitmap for g_aNoCrtPerThreadStatic.
*
* In debug builds we only have one slot here, so we have a better chance of
* testing the heap code path. */
#ifdef DEBUG
static uint32_t volatile g_fNoCrtPerThreadStaticAlloc = UINT32_C(0xffffefff);
#else
static uint32_t volatile g_fNoCrtPerThreadStaticAlloc = 0;
#endif
/* Static allocations to avoid the heap and associate slowness. */
static RTNOCRTTHREADDATA g_aNoCrtPerThreadStatic[32];
/**
* @callback_method_impl{FNRTTLSDTOR}
*/
static DECLCALLBACK(void) rtNoCrtPerThreadDtor(void *pvValue)
{
PRTNOCRTTHREADDATA pNoCrtData = (PRTNOCRTTHREADDATA)pvValue;
if (pNoCrtData->enmAllocType == RTNOCRTTHREADDATA::kAllocType_Heap)
{
AssertReturnVoid(RTOnceWasInitialized(&g_NoCrtPerThreadOnce));
RTCritSectEnter(&g_NoCrtPerThreadCritSect); /* timeout? */
RTListNodeRemove(&pNoCrtData->ListEntry);
pNoCrtData->enmAllocType = RTNOCRTTHREADDATA::kAllocType_End;
RTCritSectLeave(&g_NoCrtPerThreadCritSect);
RTMemFree(pNoCrtData);
}
else if (pNoCrtData->enmAllocType == RTNOCRTTHREADDATA::kAllocType_Static)
{
size_t iSlot = (size_t)(pNoCrtData - &g_aNoCrtPerThreadStatic[0]);
AssertReturnVoid(iSlot < RT_ELEMENTS(g_aNoCrtPerThreadStatic));
pNoCrtData->enmAllocType = RTNOCRTTHREADDATA::kAllocType_Invalid;
ASMAtomicAndU32(&g_fNoCrtPerThreadStaticAlloc, ~(uint32_t)iSlot);
}
}
/**
* @callback_method_impl{FNRTONCE}
*/
static DECLCALLBACK(int32_t) rtNoCrtPerThreadInit(void *pvUser)
{
RTListInit(&g_NoCrtPerThreadHeapList);
RTTLS iTls = NIL_RTTLS;
int rc = RTTlsAllocEx(&iTls, rtNoCrtPerThreadDtor);
if (iTls != NIL_RTTLS)
{
rc = RTCritSectInit(&g_NoCrtPerThreadCritSect);
if (RT_SUCCESS(rc))
{
g_iTlsRtNoCrtPerThread = iTls;
return VINF_SUCCESS;
}
RTTlsFree(iTls);
}
RT_NOREF(pvUser);
return rc;
}
/**
* @callback_method_impl{FNRTONCECLEANUP}
*/
static DECLCALLBACK(void) rtNoCrtPerThreadCleanup(void *pvUser, bool fLazyCleanUpOk)
{
RT_NOREF(pvUser);
if (fLazyCleanUpOk)
return;
/*
* First destroy the TLS entry.
*/
RTTLS iTls = g_iTlsRtNoCrtPerThread;
g_iTlsRtNoCrtPerThread = NIL_RTTLS;
int rc = RTTlsFree(iTls);
AssertRC(rc);
/*
* Then destroy the critical section and free all entries in the list.
*/
RTCritSectDelete(&g_NoCrtPerThreadCritSect);
PRTNOCRTTHREADDATA pNoCrtData;
while ((pNoCrtData = RTListRemoveFirst(&g_NoCrtPerThreadHeapList, RTNOCRTTHREADDATA, ListEntry)) != NULL)
{
AssertContinue(pNoCrtData->enmAllocType == RTNOCRTTHREADDATA::kAllocType_Heap);
pNoCrtData->enmAllocType = RTNOCRTTHREADDATA::kAllocType_End;
RTMemFree(pNoCrtData);
}
}
PRTNOCRTTHREADDATA rtNoCrtThreadDataGet(void)
{
int rc = RTOnceEx(&g_NoCrtPerThreadOnce, rtNoCrtPerThreadInit, rtNoCrtPerThreadCleanup, NULL);
if (RT_SUCCESS(rc))
{
/*
* We typically have an entry already.
*/
PRTNOCRTTHREADDATA pNoCrtData = (PRTNOCRTTHREADDATA)RTTlsGet(g_iTlsRtNoCrtPerThread);
if (pNoCrtData)
{
AssertReturn( pNoCrtData->enmAllocType > RTNOCRTTHREADDATA::kAllocType_Invalid
&& pNoCrtData->enmAllocType < RTNOCRTTHREADDATA::kAllocType_End,
NULL);
return pNoCrtData;
}
/*
* Okay, allocate a new entry first using some of the statically allocated
* ones then falling back on heap allocations.
*/
for (;;)
{
uint32_t const fAlloc = ASMAtomicUoReadU32(&g_fNoCrtPerThreadStaticAlloc);
uint32_t iSlot = ASMBitFirstSetU32(~fAlloc);
if (iSlot != 0)
iSlot--;
else
break;
if (ASMAtomicCmpXchgU32(&g_fNoCrtPerThreadStaticAlloc, fAlloc | RT_BIT_32(iSlot), fAlloc))
{
pNoCrtData = &g_aNoCrtPerThreadStatic[iSlot];
/* Init the entry in case it's being re-used: */
Assert(pNoCrtData->enmAllocType == RTNOCRTTHREADDATA::kAllocType_Invalid);
rc = RTTlsSet(g_iTlsRtNoCrtPerThread, pNoCrtData);
AssertRC(rc);
if (RT_SUCCESS(rc))
{
pNoCrtData->enmAllocType = RTNOCRTTHREADDATA::kAllocType_Static;
RTListInit(&pNoCrtData->ListEntry);
pNoCrtData->iErrno = 0;
pNoCrtData->pszStrToken = NULL;
return pNoCrtData;
}
ASMAtomicOrU32(&g_fNoCrtPerThreadStaticAlloc, RT_BIT_32(iSlot));
return NULL;
}
ASMNopPause();
}
/*
* Heap.
*/
pNoCrtData = (PRTNOCRTTHREADDATA)RTMemAllocZ(sizeof(*pNoCrtData));
if (pNoCrtData)
{
pNoCrtData->enmAllocType = RTNOCRTTHREADDATA::kAllocType_Heap;
RTCritSectEnter(&g_NoCrtPerThreadCritSect);
RTListAppend(&g_NoCrtPerThreadHeapList, &pNoCrtData->ListEntry);
RTCritSectLeave(&g_NoCrtPerThreadCritSect);
rc = RTTlsSet(g_iTlsRtNoCrtPerThread, pNoCrtData);
AssertRC(rc);
if (RT_SUCCESS(rc))
return pNoCrtData;
RTCritSectEnter(&g_NoCrtPerThreadCritSect);
RTListNodeRemove(&pNoCrtData->ListEntry);
RTCritSectLeave(&g_NoCrtPerThreadCritSect);
pNoCrtData->enmAllocType = RTNOCRTTHREADDATA::kAllocType_End;
RTMemFree(pNoCrtData);
}
}
return NULL;
}
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