import sys
import threading
import ctypes
from ctypes import byref
from ctypes import Structure, Union
from ctypes.wintypes import *
# other wintype definition
LPVOID = ctypes.c_void_p
LPCVOID = LPVOID
DWORD_PTR = DWORD
LONGLONG = ctypes.c_longlong
HCOUNTER = HQUERY = HANDLE
# error code
Error_Success = 0
# macro
sleep = ctypes.windll.kernel32.Sleep
pdh = ctypes.windll.pdh
# structure definition
class Sysinfo_Struct(Structure):
_fields_ = [('wProcessorArchitecture', WORD),
('wReserved', WORD)]
class Sysinfo_Union(Union):
_fields_ = [('dwOemId', DWORD),
('struct', Sysinfo_Struct)]
class System_Info(Structure):
_fields_ = [('union', Sysinfo_Union),
('dwPageSize', DWORD),
('lpMinimumApplicationAddress', LPVOID),
('lpMaximumApplicationAddress', LPVOID),
('dwActiveProcessorMask', DWORD_PTR),
('dwNumberOfProcessors', DWORD),
('dwProcessorType', DWORD),
('dwAllocationGranularity', DWORD),
('wProcessorLevel', WORD),
('wProcessorRevision', WORD)]
class PDH_Counter_Union(Union):
_fields_ = [('longValue', LONG),
('doubleValue', ctypes.c_double),
('largeValue', LONGLONG),
('AnsiStringValue', LPCSTR),
('WideStringValue', LPCWSTR)]
class PDH_FMT_COUNTERVALUE(Structure):
_fields_ = [('CStatus', DWORD),
('union', PDH_Counter_Union),]
# Exception definition
class TargetRateExceedError(Exception):
pass
def getProcessorNumber():
si = System_Info()
ctypes.windll.kernel32.GetSystemInfo(byref(si))
return si.dwNumberOfProcessors
g_cpu_usage = 0
class QueryCPUUsageThread(threading.Thread):
def __init__(self):
super(QueryCPUUsageThread, self).__init__()
self.hQuery = HQUERY()
self.hCounter = HCOUNTER()
if not pdh.PdhOpenQueryW(None, 0, byref(self.hQuery)) == Error_Success:
raise RuntimeError('[QueryCPUUsageThread] Open query failed')
if not pdh.PdhAddCounterW(self.hQuery,
u'''\\Processor(_Total)\\% Processor Time''',
0,
byref(self.hCounter)) == Error_Success:
raise RuntimeError('[QueryCPUUsageThread] Add counter failed')
def run(self):
while True:
usage = self.getCPUUsage()
global g_cpu_usage
g_cpu_usage = usage
def getCPUUsage(self):
if not pdh.PdhCollectQueryData(self.hQuery) == Error_Success:
raise RuntimeError('[QueryCPUUsageThread] CollectQueryData failed')
ctypes.windll.kernel32.Sleep(1000)
if not pdh.PdhCollectQueryData(self.hQuery) == Error_Success:
raise RuntimeError('[QueryCPUUsageThread] CollectQueryData failed')
dwType = DWORD(0)
value = PDH_FMT_COUNTERVALUE()
if not pdh.PdhGetFormattedCounterValue(self.hCounter,
0x00000100, # PDH_FMT_LONG
byref(dwType),
byref(value)) == Error_Success:
raise RuntimeError('[QueryCPUUsageThread] Get CounterValue failed')
return value.union.longValue
def main(targetRateForMainProcess, targetRate):
timeInterval = 50.0
busyTime = float(targetRateForMainProcess) * timeInterval / 100.0
idleTime = timeInterval - busyTime
TOLERANCE = 2
while True:
if len(sys.argv)<=1:
usage = g_cpu_usage
if abs(usage - targetRate) < TOLERANCE:
pass
elif usage > targetRate:
busyTime = max(busyTime - 0.1, 1)
idleTime = timeInterval - busyTime
else:
busyTime = min(busyTime + 0.1, 49)
idleTime = timeInterval - busyTime
#print busyTime, idleTime
startTime = ctypes.windll.kernel32.GetTickCount()
while ctypes.windll.kernel32.GetTickCount() - startTime < int(round(busyTime)):
pass
sleep(int(round(idleTime)))
def subpMain():
while True:
pass
def inputLoop():
while True:
print 'please input target cpu usage: ',
try:
rate = float(raw_input().strip())
if rate >= 100 or rate <=1:
raise TargetRateExceedError
except TargetRateExceedError:
print 'please input a number in range 1-99'
except Exception:
print 'please input a target cpu usage rate, e.g. 70'
else:
return rate
if __name__=='__main__':
if len(sys.argv) <= 1: # main process
targetRate = inputLoop()
nProcessor = getProcessorNumber()
fullPercentPerProcessor = 100.0 / float(nProcessor)
targetRateForMainProcess = targetRate
while targetRateForMainProcess > fullPercentPerProcessor:
from subprocess import Popen
obj=Popen([sys.executable, __file__, 'child'])
targetRateForMainProcess -= fullPercentPerProcessor
queryCpuThread = QueryCPUUsageThread()
queryCpuThread.start()
main(targetRateForMainProcess, targetRate)
else: # subprocess
subpMain()
