生成CPU使用率 sin 曲线 控制cpu使用率 编程之美
入职Oracle 以后想着把之前写过的《编程之美》中控制CPU使用率曲线的程序再写一边, 可是总是由于入职须要学习的东西太多, 没有时间。
程序早就写好了。 最终有机会贴出来了。o(∩∩)o..
最早的时候我採用C实现的效果并不好。 当时也没有认真调试。 最初的时候採用C#实现的效果反而不错, 由于C#有非常多方便的类库能够获取CPU的占用率, 控制sleep时间等等。事实上在C中也非常easy实现。
整体的算法思想, 这里就不再反复了, 能够參考以下的链接 :
http://blog.csdn.net/watkinsong/article/details/6865775
http://blog.csdn.net/watkinsong/article/details/6867373
http://blog.csdn.net/watkinsong/article/details/6867473
http://blog.csdn.net/watkinsong/article/details/6867666
http://blog.csdn.net/watkinsong/article/details/6870748
http://blog.csdn.net/watkinsong/article/details/6871235
本次算法的实现, 全部的代码都托管到了github, 而且使用了makefile编译文件。
地址: https://github.com/weixsong/aventador
以下简单的给出代码和效果截图。 这里的效果实现比曾经的C#实现的那个sin曲线要好一些。
#define _GNU_SOURCE #include <stdio.h> #include <stdlib.h> #include <sched.h> #include <unistd.h> extern const double PI = 3.1415926; // setup the cpu set of this program to run on int set_cpu(int id) { cpu_set_t mask; CPU_ZERO(&mask); CPU_SET(id, &mask); if (sched_setaffinity(0, sizeof(mask), &mask) == -1) { fprintf(stderr, "warning: could not set CPU affinity/n"); return 0; } return 1; }
#include <stdio.h> #include <stdlib.h> #include <time.h> #include <math.h> #include <unistd.h> #include "CPUtils.h" const int CPU_KERNEL_ID = 0x0003; const int SAMPLE_COUNT = 200; const int TIME_SLICE = 200; // ms in second const int TIME_TRANFORM = 1000; // change ms to us long * busy_span; // init the busy span, this is used to control the cpu busy time for each sample point int init_busySpan(int sample_count) { busy_span = (long *)malloc(sample_count * sizeof(long)); if(busy_span == NULL) { return -1; } double radian = 0.0; double radianIncrement = 2.0 / (double)sample_count; int amplitude = (int)(TIME_SLICE / 2); // amplitude of sin curves, it means half of the time slice because sin() has negative value int i; for(i = 0; i < sample_count; i++) { busy_span[i] = (long)(amplitude + sin(radian * PI) * amplitude); radian = radian + radianIncrement; } return 1; } int main(void) { if(set_cpu(CPU_KERNEL_ID) == 0) { printf("cpu affinity set failed\n"); } else { printf("cpu affinity set succeeded\n"); } printf("clock per second:%ld \n", CLOCKS_PER_SEC); fflush(stdout); if(!(init_busySpan(SAMPLE_COUNT))) { printf("init error \n"); return 0; } int i = 0; long busy_time; // us long sleep_time; // us clock_t begin; for(i = 0; ; i = (i + 1) % SAMPLE_COUNT) { busy_time = busy_span[i] * TIME_TRANFORM; begin = clock(); while((clock() - begin) < busy_time) { // loop } sleep_time = (long)((TIME_SLICE - busy_span[i])) * TIME_TRANFORM; usleep(sleep_time); } return 1; }
posted on 2017-06-12 12:57 gavanwanggw 阅读(740) 评论(1) 编辑 收藏 举报