通过 python 获取内存使用情况

Question

我在使用 检索系统的内存使用情况时遇到问题。psutil当我运行我的代码时，它会正确检索CPU使用率，但是当它尝试获取内存时，它会引发AccessDenied错误。法典：if(pi['name']=='java.exe'):     pro=psutil.Process(0)     cpu=pro.cpu_percent(1)     memory=pro.memory_full_info().uss/(1024*1024)         return memory,cpu错误信息：psutil.AccessDenied (pid=0)如何获取内存使用量？

Answer 1

psutil.Process()采用一个参数 - 进程标识符 （PID）。如果调用它时没有参数或带有 ，则使用当前进程的 pid。None

在 Window 上，pid 0 是系统空闲进程，它需要特权。SYSTEM

pro=psutil.Process(0) # here's your problem

如果要获取 的内存/CPU 使用率，则必须获取 pid，然后使用 。在下面的示例中，我使用了：java.exepsutilfirefox.exe

import psutil

from ctypes import *

from ctypes.wintypes import *

class PROCESSENTRY32W(Structure):

    _fields_ = [("dwSize", DWORD),

                ("cntUsage", DWORD),

                ("th32ProcessID", DWORD),

                ("th32DefaultHeapID", POINTER(ULONG)),

                ("th32ModuleID", DWORD),

                ("cntThreads", DWORD),

                ("th32ParentProcessID", DWORD),

                ("pcPriClassBase", LONG),

                ("dwFlags", DWORD),

                ("szExeFile", c_wchar * MAX_PATH)]

def get_processes():

    TH32CS_SNAPPROCESS = 0x00000002

    INVALID_HANDLE_VALUE = -1

    CreateToolhelp32Snapshot = windll.kernel32.CreateToolhelp32Snapshot

    CreateToolhelp32Snapshot.argtypes = [DWORD, DWORD]

    CreateToolhelp32Snapshot.restype = HANDLE

    Process32FirstW = windll.kernel32.Process32FirstW

    Process32FirstW.argtypes = [HANDLE, POINTER(PROCESSENTRY32W)]

    Process32FirstW.restype = BOOL

    Process32NextW = windll.kernel32.Process32NextW

    Process32NextW.argtypes = [HANDLE, POINTER(PROCESSENTRY32W)]

    Process32NextW.restype = BOOL

    CloseHandle = windll.kernel32.CloseHandle

    CloseHandle.argtypes = [HANDLE]

    CloseHandle.restype = BOOL

    snapshot = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0)

    if snapshot == INVALID_HANDLE_VALUE:

        return []

    try:

        process_entry = PROCESSENTRY32W()

        process_entry.dwSize = sizeof(PROCESSENTRY32W)

        if not Process32FirstW(snapshot, byref(process_entry)):

            return []

        processes = []

        while Process32NextW(snapshot, byref(process_entry)):

            processes.append((process_entry.th32ProcessID, process_entry.szExeFile))

    finally:

        CloseHandle(snapshot)

        #print("Closed handle")

    return processes

for pid, name in get_processes():

    if name == "firefox.exe":

        pro = psutil.Process(pid)

        cpu = pro.cpu_percent(1.0)

        memory = pro.memory_full_info().uss/(1024*1024)

        print(memory, cpu)

输出：

471.2890625 1.6

127.15234375 25.0

18.50390625 0.0

668.09375 0.0

706.6875 0.0

512.671875 0.0

648.953125 4.7

1037.0859375 4.7

1160.1015625 98.4

337.46484375 0.0

1418.72265625 1.6

0.90625 0.0

0.90625 0.0