在Windows中使用ctypes的错误虚拟内存报告

Question

i am trying to get the total/available virtual memory in python using ctypes, but it seems to be returning a highly incorrect value. below is the code i currently have

import ctypes
import ctypes.wintypes as wintypes

def _get_virtual_size():
    class MEMORYSTATUSEX(ctypes.Structure):
        _fields_ = [("dwLength", wintypes.DWORD),
                    ("dwMemoryLoad", wintypes.DWORD),
                    ("ullTotalPhys", ctypes.c_uint64),
                    ("ullAvailPhys", ctypes.c_uint64),
                    ("ullTotalPageFile", ctypes.c_uint64),
                    ("ullAvailPageFile", ctypes.c_uint64),
                    ("ullTotalVirtual", ctypes.c_uint64),
                    ("ullAvailVirtual", ctypes.c_uint64),
                    ("ullAvailExtendedVirtual", ctypes.c_uint64)]

        def __init__(self):
            ctypes.Structure.__init__(self)
            self.dwLength = ctypes.sizeof(self)

    kernel32 = ctypes.WinDLL("kernel32", use_last_error=True)
    GlobalMemoryStatusEx = kernel32.GlobalMemoryStatusEx
    GlobalMemoryStatusEx.restype = wintypes.BOOL
    GlobalMemoryStatusEx.argtypes = [ctypes.POINTER(MEMORYSTATUSEX)]

    status = MEMORYSTATUSEX()
    if GlobalMemoryStatusEx(status):
        return {'totalPage':status.ullAvailPageFile,  'total':status.ullTotalVirtual, 'available':status.ullAvailVirtual}
    return None

print _get_virtual_size()

Result: {'available': 140737380003840L, 'totalPage': 13305126912L, 'total': 140737488224256L}

Note : Using psutil the value seems to be reported correctly, but need a solution without using psutil.

import psutil
print psutil.virtual_memory()

Result: svmem(total=17114841088L, available=13436207104L, percent=21.5, used=3678633984L, free=13436207104L)

How do i get the same values reported by psutil using the ctypes method. I am currently running the above code in Python 2.7.10 64Bit on Windows 8.1

Any help would be appreciated.

Answer 1

Try using this code. Not sure if it will work for you. I'm running 32-bit Python on a 64-bit windows 7 pc {Python 2.7.6 (default, Nov 10 2013, 19:24:18) [MSC v.1500 32 bit (Intel)] on win32} . I have compared the values returned to what is reported in the Performance tab of my Windows Task Manager application.

import ctypes

class MEMORYSTATUSEX(ctypes.Structure):
    _fields_ = [
        ("dwLength", ctypes.c_ulong),
        ("dwMemoryLoad", ctypes.c_ulong),
        ("ullTotalPhys", ctypes.c_ulonglong),
        ("ullAvailPhys", ctypes.c_ulonglong),
        ("ullTotalPageFile", ctypes.c_ulonglong),
        ("ullAvailPageFile", ctypes.c_ulonglong),
        ("ullTotalVirtual", ctypes.c_ulonglong),
        ("ullAvailVirtual", ctypes.c_ulonglong),
        ("ullAvailExtendedVirtual", ctypes.c_ulonglong)
    ]

    def __init__(self):
        # have to initialize this to the size of MEMORYSTATUSEX
        self.dwLength = ctypes.sizeof(self)
        super(MEMORYSTATUSEX, self).__init__()

stat = MEMORYSTATUSEX()
ctypes.windll.kernel32.GlobalMemoryStatusEx(ctypes.byref(stat))

print("MemoryLoad: %d%%" % (stat.dwMemoryLoad))
print . . . #output other fields here