Zabbix

/*

** Copyright (C) 2001-2025 Zabbix SIA

**

** This program is free software: you can redistribute it and/or modify it under the terms of

** the GNU Affero General Public License as published by the Free Software Foundation, version 3.

**

** 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 Affero General Public License for more details.

**

** You should have received a copy of the GNU Affero General Public License along with this program.

** If not, see <https://www.gnu.org/licenses/>.

**/

​

#include "zbxsysinfo.h"

#include "../sysinfo.h"

#include "win32_cpu.h"

​

#include "../common/stats.h"

#include "perfstat/perfstat.h"

​

/* shortcut to avoid extra verbosity */

typedef PSYSTEM_LOGICAL_PROCESSOR_INFORMATION_EX PSYS_LPI_EX;

​

/* pointer to GetLogicalProcessorInformationEx(), it's not guaranteed to be available */

typedef BOOL (WINAPI *GETLPIEX)(LOGICAL_PROCESSOR_RELATIONSHIP, PSYS_LPI_EX, PDWORD);

static GETLPIEX     get_lpiex;

​

/******************************************************************************

 *                                                                            *

 * Purpose: finds number of active logical CPUs                               *

 *                                                                            *

 * Return value: number of CPUs or 0 on failure                               *

 *                                                                            *

 ******************************************************************************/

int get_cpu_num_win32(void)

{

    /* pointer to GetActiveProcessorCount() */

    typedef DWORD (WINAPI *GETACTIVEPC)(WORD);

​

    ZBX_THREAD_LOCAL static GETACTIVEPC get_act;

    SYSTEM_INFO             sysInfo;

    PSYS_LPI_EX             buffer = NULL;

    int                 cpu_count = 0;

​

    /* The rationale for checking dynamically if specific functions are implemented */

    /* in kernel32.lib is because these may not be available in certain Windows versions. */

    /* E.g. GetActiveProcessorCount() is available from Windows 7 onward (and not in Windows Vista or XP) */

    /* We can't resolve this using conditional compilation unless we release multiple agents */

    /* targeting different sets of Windows APIs. */

​

    /* First, let's try GetLogicalProcessorInformationEx() method. It's the most reliable way */

    /* because it counts logical CPUs (aka threads) regardless of whether the application is */

    /* 32 or 64-bit. GetActiveProcessorCount() may return incorrect value (e.g. 64 CPUs for systems */

    /* with 128 CPUs) if executed under WoW64. */

​

    if (NULL == get_lpiex)

    {

        get_lpiex = (GETLPIEX)GetProcAddress(GetModuleHandle(L"kernel32.dll"),

                "GetLogicalProcessorInformationEx");

    }

​

    if (NULL != get_lpiex)

    {

        DWORD buffer_length = 0;

​

        /* first run with empty arguments to figure the buffer length */

        if (get_lpiex(RelationProcessorCore, NULL, &buffer_length) ||

                ERROR_INSUFFICIENT_BUFFER != GetLastError())

        {

            goto fallback;

        }

​

        buffer = (PSYS_LPI_EX)zbx_malloc(buffer, (size_t)buffer_length);

​

        if (get_lpiex(RelationProcessorCore, buffer, &buffer_length))

        {

            PSYS_LPI_EX ptr;

​

            for (unsigned int i = 0; i < buffer_length; i += (unsigned int)ptr->Size)

            {

                ptr = (PSYS_LPI_EX)((PBYTE)buffer + i);

​

                for (WORD group = 0; group < ptr->Processor.GroupCount; group++)

                {

                    for (KAFFINITY mask = ptr->Processor.GroupMask[group].Mask; mask != 0;

                            mask >>= 1)

                    {

                        cpu_count += mask & 1;

                    }

                }