测试一下
linux-p94b:/tmp/testhere # gcc -O2 test1.c -lpthread linux-p94b:/tmp/testhere # for((i=0;i<10;i++));do ./a.out ; done cnt = 1000000000 cnt = 1000000000 cnt = 1000000000 cnt = 1000000000 cnt = 1000000000 cnt = 1000000000 cnt = 1000000000 cnt = 1000000000 cnt = 1000000000 cnt = 1000000000