写程序让用户来决定Windows任务管理器的CPU占有率

最新推荐文章于 2017-07-04 14:47:32 发布

原创最新推荐文章于 2017-07-04 14:47:32 发布 · 730 阅读

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本文提供三种模拟CPU占用率的方法：固定50%占用率、由命令行参数设定具体占用率及正弦曲线变化的占用率。通过Windows API函数GetTickCount()和Sleep()实现精确的时间控制。

1、CPU的占用率固定在50%，为一条直线

代码：

#include <windows.h>
int main(void)
{
//50%
int busyTime=10;
int idleTime=busyTime;
_int64 startTime;
SetThreadAffinityMask(GetCurrentProcess(), 0x00000001);
while(true)
{ startTime=GetTickCount(); //获取从系统从开机到此刻
while((GetTickCount()-startTime)<=busyTime)
{ ; }
Sleep(idleTime);
}
return 0;
}

2、CPU的占用率为一条直线，但是具体占用率由命令行参数决定（参数范围1~100）

#include<stdio.h>

void main()

{

int busyTime=10; //10ms

int idleTime=busyTime;

int64 startTime=0;

while(true)

{

startTime=GetTickCount();

while( GetTickCount()-starTime <=busyTime ) ;

sleep(idleTime);

}

3、CPU的占用率状态是一个正弦曲线

代码：

#include<windows.h>
#include<cstdio>
#include<cmath>
const int PERIOD = 60 * 1000; //60,000 ms
const int COUNT = 200;
const double PI = 3.1415926535898;
const double GAP = (double)PERIOD / COUNT;
const double FACTOR = 2 * PI / PERIOD;
typedef double Func(double);
inline DWORD get_time() { return GetTickCount(); }
double calc2(double x) { return (1 + sin(FACTOR * x)) / 2;}
double calc3(double)
{
static double cache[COUNT];
static int count = 0;
static bool first = true;
if (first) {
double x = 0.0;
for (int i = 0; i < COUNT; ++i, x += GAP)
cache[i] = (1.0 + sin(FACTOR * x)) / 2.0;
first = false;
}
if (count >= COUNT) count = 0;
return cache[count++];
}
double calc4(double) { return 0.8;}
void solve(Func *calc)
{
double tb = 0;
while(1) {
unsigned ta = get_time();
double r = calc(tb);
if (r < 0 || r > 1) r = 1;
DWORD busy = r * GAP;
while(get_time() - ta < busy) {}
Sleep(GAP - busy);
tb += GAP;
}
}
void run()
{
Func *func[] = { calc2, calc3, calc4 };
Func *calc = func[1];
const int MAX_CPUS = 32;
HANDLE handle[MAX_CPUS];
DWORD thread_id[MAX_CPUS];
SYSTEM_INFO info;
GetSystemInfo(&info);
const int num = info.dwNumberOfProcessors;
for (int i = 0; i < num; ++i) {
if ( (handle[i] = CreateThread(NULL, 0, (LPTHREAD_START_ROUTINE)solve,
(VOID*)calc, 0, &thread_id[i])) != NULL)
SetThreadAffinityMask(handle[i], i + 1);
}
WaitForSingleObject(handle[0],INFINITE);
}
int main()
{
run();
}