| 1 | /* $Id: RTMpGetArraySize-generic.cpp 106061 2024-09-16 14:03:52Z vboxsync $ */
|
|---|
| 2 | /** @file
|
|---|
| 3 | * IPRT - Multiprocessor, Generic RTMpGetArraySize.
|
|---|
| 4 | */
|
|---|
| 5 |
|
|---|
| 6 | /*
|
|---|
| 7 | * Copyright (C) 2010-2024 Oracle and/or its affiliates.
|
|---|
| 8 | *
|
|---|
| 9 | * This file is part of VirtualBox base platform packages, as
|
|---|
| 10 | * available from https://www.virtualbox.org.
|
|---|
| 11 | *
|
|---|
| 12 | * This program is free software; you can redistribute it and/or
|
|---|
| 13 | * modify it under the terms of the GNU General Public License
|
|---|
| 14 | * as published by the Free Software Foundation, in version 3 of the
|
|---|
| 15 | * License.
|
|---|
| 16 | *
|
|---|
| 17 | * This program is distributed in the hope that it will be useful, but
|
|---|
| 18 | * WITHOUT ANY WARRANTY; without even the implied warranty of
|
|---|
| 19 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|---|
| 20 | * General Public License for more details.
|
|---|
| 21 | *
|
|---|
| 22 | * You should have received a copy of the GNU General Public License
|
|---|
| 23 | * along with this program; if not, see <https://www.gnu.org/licenses>.
|
|---|
| 24 | *
|
|---|
| 25 | * The contents of this file may alternatively be used under the terms
|
|---|
| 26 | * of the Common Development and Distribution License Version 1.0
|
|---|
| 27 | * (CDDL), a copy of it is provided in the "COPYING.CDDL" file included
|
|---|
| 28 | * in the VirtualBox distribution, in which case the provisions of the
|
|---|
| 29 | * CDDL are applicable instead of those of the GPL.
|
|---|
| 30 | *
|
|---|
| 31 | * You may elect to license modified versions of this file under the
|
|---|
| 32 | * terms and conditions of either the GPL or the CDDL or both.
|
|---|
| 33 | *
|
|---|
| 34 | * SPDX-License-Identifier: GPL-3.0-only OR CDDL-1.0
|
|---|
| 35 | */
|
|---|
| 36 |
|
|---|
| 37 |
|
|---|
| 38 | /*********************************************************************************************************************************
|
|---|
| 39 | * Header Files *
|
|---|
| 40 | *********************************************************************************************************************************/
|
|---|
| 41 | #include <iprt/mp.h>
|
|---|
| 42 | #include "internal/iprt.h"
|
|---|
| 43 |
|
|---|
| 44 | #include <iprt/asm.h>
|
|---|
| 45 | #include <iprt/cpuset.h>
|
|---|
| 46 |
|
|---|
| 47 |
|
|---|
| 48 | RTDECL(uint32_t) RTMpGetArraySize(void)
|
|---|
| 49 | {
|
|---|
| 50 | /*
|
|---|
| 51 | * Cache the result here. This whole point of this function is that it
|
|---|
| 52 | * will always return the same value, so that should be safe.
|
|---|
| 53 | *
|
|---|
| 54 | * Note! Because RTCPUSET may be to small to represent all the CPUs, we
|
|---|
| 55 | * check with RTMpGetCount() as well.
|
|---|
| 56 | */
|
|---|
| 57 | static uint32_t s_cMaxCpus = 0;
|
|---|
| 58 | uint32_t cCpus = s_cMaxCpus;
|
|---|
| 59 | if (RT_UNLIKELY(cCpus == 0))
|
|---|
| 60 | {
|
|---|
| 61 | RTCPUSET CpuSet;
|
|---|
| 62 | uint32_t cCpus1 = RTCpuLastIndex(RTMpGetSet(&CpuSet)) + 1;
|
|---|
| 63 | uint32_t cCpus2 = RTMpGetCount();
|
|---|
| 64 | cCpus = RT_MAX(cCpus1, cCpus2);
|
|---|
| 65 | ASMAtomicCmpXchgU32(&s_cMaxCpus, cCpus, 0);
|
|---|
| 66 | return cCpus;
|
|---|
| 67 | }
|
|---|
| 68 | return s_cMaxCpus;
|
|---|
| 69 |
|
|---|
| 70 | }
|
|---|
| 71 | RT_EXPORT_SYMBOL(RTMpGetArraySize);
|
|---|
| 72 |
|
|---|
