Windows获取物理内存的2种方式 - 随笔记录

 typedef enum _SYSTEM_INFORMATION_CLASS {
     SystemBasicInformation,
     SystemProcessorInformation,             // obsolete...delete
     SystemPerformanceInformation,
     SystemTimeOfDayInformation,
     SystemPathInformation,
     SystemProcessInformation,
     SystemCallCountInformation,
     SystemDeviceInformation,
     SystemProcessorPerformanceInformation,
     SystemFlagsInformation,
     SystemCallTimeInformation,
     SystemModuleInformation,
     SystemLocksInformation,
     SystemStackTraceInformation,
     SystemPagedPoolInformation,
     SystemNonPagedPoolInformation,
     SystemHandleInformation,
     SystemObjectInformation,
     SystemPageFileInformation,
     SystemVdmInstemulInformation,
     SystemVdmBopInformation,
     SystemFileCacheInformation,
     SystemPoolTagInformation,
     SystemInterruptInformation,
     SystemDpcBehaviorInformation,
     SystemFullMemoryInformation,
     SystemLoadGdiDriverInformation,
     SystemUnloadGdiDriverInformation,
     SystemTimeAdjustmentInformation,
     SystemSummaryMemoryInformation,
     SystemMirrorMemoryInformation,
     SystemPerformanceTraceInformation,
     SystemObsolete0,
     SystemExceptionInformation,
     SystemCrashDumpStateInformation,
     SystemKernelDebuggerInformation,
     SystemContextSwitchInformation,
     SystemRegistryQuotaInformation,
     SystemExtendServiceTableInformation,
     SystemPrioritySeperation,
     SystemVerifierAddDriverInformation,
     SystemVerifierRemoveDriverInformation,
     SystemProcessorIdleInformation,
     SystemLegacyDriverInformation,
     SystemCurrentTimeZoneInformation,
     SystemLookasideInformation,
     SystemTimeSlipNotification,
     SystemSessionCreate,
     SystemSessionDetach,
     SystemSessionInformation,
     SystemRangeStartInformation,
     SystemVerifierInformation,
     SystemVerifierThunkExtend,
     SystemSessionProcessInformation,
     SystemLoadGdiDriverInSystemSpace,
     SystemNumaProcessorMap,
     SystemPrefetcherInformation,
     SystemExtendedProcessInformation,
     SystemRecommendedSharedDataAlignment,
     SystemComPlusPackage,
     SystemNumaAvailableMemory,
     SystemProcessorPowerInformation,
     SystemEmulationBasicInformation,
     SystemEmulationProcessorInformation,
     SystemExtendedHandleInformation,
     SystemLostDelayedWriteInformation,
     SystemBigPoolInformation,
     SystemSessionPoolTagInformation,
     SystemSessionMappedViewInformation,
     SystemHotpatchInformation,
     SystemObjectSecurityMode,
     SystemWatchdogTimerHandler,
     SystemWatchdogTimerInformation,
     SystemLogicalProcessorInformation,
     SystemWow64SharedInformation,
     SystemRegisterFirmwareTableInformationHandler,
     SystemFirmwareTableInformation,
     SystemModuleInformationEx,
     SystemVerifierTriageInformation,
     SystemSuperfetchInformation,
     SystemMemoryListInformation,
     SystemFileCacheInformationEx,
     MaxSystemInfoClass,  // MaxSystemInfoClass should always be the last enum

     SystemPageMemoryInformation =
 } SYSTEM_INFORMATION_CLASS, *PSYSTEM_INFORMATION_CLASS;

 typedef struct _SYSTEM_BASIC_INFORMATION
 {
     ULONG Unknown; //Always contains zero
     ULONG MaximumIncrement; //一个时钟的计量单位
     ULONG PhysicalPageSize; //一个内存页的大小
     ULONG NumberOfPhysicalPages; //系统管理着多少个页
     ULONG LowestPhysicalPage; //低端内存页
     ULONG HighestPhysicalPage; //高端内存页
     ULONG AllocationGranularity;
     ULONG LowestUserAddress; //地端用户地址
     ULONG HighestUserAddress; //高端用户地址
     ULONG ActiveProcessors; //激活的处理器
     UCHAR NumberProcessors; //有多少个处理器
 }SYSTEM_BASIC_INFORMATION, *PSYSTEM_BASIC_INFORMATION;

 NTSTATUS (__stdcall *ZwQuerySystemInformation)(
     _In_      SYSTEM_INFORMATION_CLASS SystemInformationClass,
     _Inout_   PVOID                    SystemInformation,
     _In_      ULONG                    SystemInformationLength,
     _Out_opt_ PULONG                   ReturnLength) = ;

 int _tmain(int argc, _TCHAR* argv[])
 {
     //方式一 ZwQuerySystemInformation
     HMODULE hNtdll = GetModuleHandle(_T("ntdll.dll"));
     *(LPVOID *)&ZwQuerySystemInformation = GetProcAddress(hNtdll, "ZwQuerySystemInformation");

     SYSTEM_BASIC_INFORMATION sbi = {  };
     ZwQuerySystemInformation(
         SystemBasicInformation,
         &sbi,
         sizeof(sbi),
         NULL);

     unsigned __int64 nsize = (unsigned __int64)sbi.NumberOfPhysicalPages * sbi.PhysicalPageSize;

     //方式二 GlobalMemoryStatusEx
     MEMORYSTATUSEX msex;
     msex.dwLength = sizeof(msex);
     GlobalMemoryStatusEx(&msex);
     msex.ullTotalPhys;//物理内存大小

     return ;
 }