#include "stress.h"

void usage(void)
{
    printf("Usage: stress [-t n] [-m n]\n");
    printf("\t-t n\tRun n processes parallel\n");
    printf("\t-m n\tTest n MiB of Memory\n");
    printf("\n");
    printf("\t\tCan be combined\n");
    exit(0);
}

void testMemory(unsigned long long size)
{
    char *mem=malloc(size*sizeof(char));
    unsigned long long i;
    unsigned char run=0;

    while(1==1)
    {
        for(i=0; i<size; i++)
        {
            mem[i]=(mem[i]+i+run)%256;
        }
        run++;
    }
}

void testCPU(void)
{
    long double f=0;
    long double res=0;
    while(1==1)
    {
        for(f=0; f<LDBL_MAX; f+=LDBL_EPSILON)
        {
            res=sqrtl(f);
        }
    }
}

int main(int argc, char **argv)
{
    const char *optargs = "t:m:h";
    char optc;
    unsigned long long convtemp;

    unsigned char errflags=0;
    unsigned char optflags=0;

    unsigned char threads = 1;
    unsigned long long memory = 1048576LL;

    int i, pid, wstatus;

    while((optc=getopt(argc,argv,optargs))!=-1)
    {
        switch(optc)
        {
        case 't':
            if((convtemp = strtoll(optarg, NULL, 10))==0)
            {
                errflags|=THREADS;
                perror("Error with -t: ");
            }
            else
            {
                optflags|=THREADS;
                threads=convtemp;
            }
            break;
        case 'm':
            if((convtemp = strtoll(optarg, NULL, 10))==0)
            {
                errflags|=MEMSIZE;
                perror("Error with -m: ");
            }
            else
            {
                optflags|=MEMSIZE;
                memory=convtemp*1024*1024;
            }
            break;
        case 'h':
        case '?':
        default:
            usage();
        }
    }

    if(errflags>0)
    {
        usage();
    }
    if(optflags & THREADS)
    {
        printf("Threads: %d\n", threads);
    }
    if(optflags & MEMSIZE)
    {
        printf("Memsize: %llu\n", memory);
    }

    for(i=0; i<threads; i++)
    {
        switch(pid=fork())
        {
        case -1:
            perror("fork()");
            break;
        case 0:
            if(optflags&MEMSIZE)
              testMemory(memory/threads);
            else
              testCPU();
            break;
        }
    }
    for(i=0; i<threads; i++)
    {
        wait(&wstatus);
    }

    return 0;
}