前几天无聊，按照《编程之美》第一题写了个控制CPU使用率的程序，把自己的代码贴出来，供以后学习……
效果图如下：
Windows下截图
其实程序的设计思想很简单，Windows任务管理器中CPU使用率基本上1s刷新一次，而CPU使用率其实就是在1s中CPU忙和闲时间的均值。因此，根据我们想要得到的CPU曲线的特点，我们首先做出忙闲时间的表，CPU根据忙闲时间选择执行或挂起。
代码如下：
#include
#include
#include
#define COUNT 200
const double SPLIT = 0.01;
const double PI = 3.14159265;
const double SLOPE = 150;
const int INTERVAL = 300;
DWORD WINAPI SineThread(LPVOID Sine)
{
DWORD busySpan[COUNT];
DWORD idleSpan[COUNT];
int half = INTERVAL/2;
double radian = 0.0;
DWORD startTime;
int i;
for (i=0; i {
busySpan[i] = (DWORD)(half + half*sin(PI*radian));
idleSpan[i] = (DWORD)(INTERVAL - busySpan[i]);
radian += SPLIT;
}
i = 0;
while(1)
{
i %= COUNT;
startTime = GetTickCount();
while((GetTickCount()-startTime) <= busySpan[i])
;
Sleep(idleSpan[i]);
i++;
}
return 0;
}
DWORD WINAPI SawThread(LPVOID Saw)
{
DWORD busySpan[COUNT];
DWORD idleSpan[COUNT];
int half = INTERVAL/2;
double radian = 0.0;
DWORD startTime;
int i;
for (i=0; i {
busySpan[i] = (DWORD)(SLOPE*radian);
idleSpan[i] = (DWORD)(INTERVAL - busySpan[i]);
radian += SPLIT;
}
i = 0;
while(1)
{
i %= COUNT;
startTime = GetTickCount();
while((GetTickCount()-startTime) <= busySpan[i])
;
Sleep(idleSpan[i]);
i++;
}
return 0;
}
int main()
{
HANDLE hThread1, hThread2;
DWORD dwThreadId1, dwThreadId2;
hThread1 = CreateThread(NULL, 0, SineThread, 0, CREATE_SUSPENDED, &dwThreadId1);
hThread2 = CreateThread(NULL, 0, SawThread, 0, CREATE_SUSPENDED, &dwThreadId2);
SetThreadAffinityMask(hThread1, 1);
SetThreadAffinityMask(hThread2, 2);
ResumeThread(hThread1);
ResumeThread(hThread2);
SuspendThread(GetCurrentThread());
return 0;
}