OpenMP Hello World

▶ OpenMP 环境配置，第一个程序

▶ OpenMP 在Visual Studio 2015 中的配置

● VS项目属性右键，属性，C/C++，语言，OpenMP支持，选择是(/openmp)。

　　

▶ 第一个程序

● 代码

 #include <stdio.h>
 #include <stdlib.h>
 #include <omp.h>   

 const int thread = ;

 void hello(void)
 {
 #   ifdef _OPENMP   // 检查是否支持 OpemMP，其值为发布年月
     const int rank = omp_get_thread_num(), size = omp_get_num_threads();
     printf("Hello from thread %d of %d\n", rank, size);
 #   else
     printf("Not support for OpenMP, use one thread.\n");
 #   endif
 }

 int main(int argc, char* argv[])
 {
     int threadReal = thread;
     if (argc >  && *argv[] > ''&& *argv[] < '')
         threadReal = atoi(argv[]);

 #   pragma omp parallel num_threads(threadReal)// 使用指定的线程数扩展接下来的一条语句
     hello();

     printf("\nfinish.\n");
     getchar();
     return ;
 }

● 输出结果

Hello from thread   of
Hello from thread   of
Hello from thread   of
Hello from thread   of
Hello from thread   of
Hello from thread   of
Hello from thread   of
Hello from thread   of  

finish.