python - 如何在 win7x64 上从 python 获取 PrivateUsage 内存值

Question

我使用以下代码，它在 WinXPx32 上运行良好，但在 Win7x64 上返回 0。我知道 psutil 库也会返回它，但我需要一些可以在没有额外依赖项的情况下运行的东西，ctypes 和 win32api 就可以了。我还尝试了 Kernel32.K32GetProcessMemoryInfo，结果相同。

import ctypes

psapi = ctypes.windll.psapi
Kernel32 = ctypes.windll.Kernel32

class PROCESS_MEMORY_COUNTERS_EX(ctypes.Structure):
    _fields_ = [("cb", ctypes.c_ulong),
                ("PageFaultCount", ctypes.c_ulong),
                ("PeakWorkingSetSize", ctypes.c_size_t),
                ("WorkingSetSize", ctypes.c_size_t),
                ("QuotaPeakPagedPoolUsage", ctypes.c_size_t),
                ("QuotaPagedPoolUsage", ctypes.c_size_t),
                ("QuotaPeakNonPagedPoolUsage", ctypes.c_size_t),
                ("QuotaNonPagedPoolUsage", ctypes.c_size_t),
                ("PagefileUsage", ctypes.c_size_t),
                ("PeakPagefileUsage", ctypes.c_size_t),
                ("PrivateUsage", ctypes.c_size_t),
                ]

def GetProcessPrivateUsage():
    mem_struct = PROCESS_MEMORY_COUNTERS_EX()
    p_handle = Kernel32.GetCurrentProcess()
    b = psapi.GetProcessMemoryInfo(p_handle, ctypes.byref(mem_struct), ctypes.sizeof(mem_struct))
    print(b)
    return mem_struct.PrivateUsage

print(GetProcessPrivateUsage())

Answer 1

我怀疑问题是由于 HANDLE 在 64 位 Windows 上是 64 位，但在 32 位 Windows 上是 32 位。默认的 ctypes 返回类型是 int，在两个系统上都是 32 位。有时它会工作，因为高 64 位恰好是正确的，但不能保证。

这与我们在 CherryPy 中通过没有显式参数和返回类型的 ctypes 调用 SetHandleInformation 时遇到的问题相同，which I described here .

您需要做的是明确指定正在调用的 Win32 函数的 argtypes 和 restype 属性。这是我制作的一个 processutil.py 模块，它适用于 32 位和 64 位 Windows(我还上传了一个 ActiveState recipe ):

"""Functions for getting memory usage of Windows processes."""

__all__ = ['get_current_process', 'get_memory_info', 'get_memory_usage']

import ctypes
from ctypes import wintypes

GetCurrentProcess = ctypes.windll.kernel32.GetCurrentProcess
GetCurrentProcess.argtypes = []
GetCurrentProcess.restype = wintypes.HANDLE

SIZE_T = ctypes.c_size_t

class PROCESS_MEMORY_COUNTERS_EX(ctypes.Structure):
    _fields_ = [
        ('cb', wintypes.DWORD),
        ('PageFaultCount', wintypes.DWORD),
        ('PeakWorkingSetSize', SIZE_T),
        ('WorkingSetSize', SIZE_T),
        ('QuotaPeakPagedPoolUsage', SIZE_T),
        ('QuotaPagedPoolUsage', SIZE_T),
        ('QuotaPeakNonPagedPoolUsage', SIZE_T),
        ('QuotaNonPagedPoolUsage', SIZE_T),
        ('PagefileUsage', SIZE_T),
        ('PeakPagefileUsage', SIZE_T),
        ('PrivateUsage', SIZE_T),
    ]

GetProcessMemoryInfo = ctypes.windll.psapi.GetProcessMemoryInfo
GetProcessMemoryInfo.argtypes = [
    wintypes.HANDLE,
    ctypes.POINTER(PROCESS_MEMORY_COUNTERS_EX),
    wintypes.DWORD,
]
GetProcessMemoryInfo.restype = wintypes.BOOL

def get_current_process():
    """Return handle to current process."""
    return GetCurrentProcess()

def get_memory_info(process=None):
    """Return Win32 process memory counters structure as a dict."""
    if process is None:
        process = get_current_process()
    counters = PROCESS_MEMORY_COUNTERS_EX()
    ret = GetProcessMemoryInfo(process, ctypes.byref(counters),
                               ctypes.sizeof(counters))
    if not ret:
        raise ctypes.WinError()
    info = dict((name, getattr(counters, name))
                for name, _ in counters._fields_)
    return info

def get_memory_usage(process=None):
    """Return this process's memory usage in bytes."""
    info = get_memory_info(process=process)
    return info['PrivateUsage']

if __name__ == '__main__':
    import pprint
    pprint.pprint(get_memory_info())