memtest.c

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <sys/time.h>

int main(int argc, char** argv)
{
        int bufsize;
        int numiter;
        int lcv;

        struct timeval  start_tv;
        struct timeval  end_tv;
        double delta;

        char* buf1;
        char* buf2;

        if ( argc < 2 )
        {
                printf("Usage: %s <buffer size in bytes> <number of iterations>\                                              n", argv[0]);
                exit(1);
        }

        bufsize = atoi(argv[1]);
        numiter = atoi(argv[2]);

        if ( bufsize <= 0 || numiter <= 0 )
        {
                printf("Usage: %s <buffer size in bytes> <number of iterations>\                                              n", argv[0]);
                exit(1);
        }

        buf1 = malloc(sizeof(char) * bufsize);
        buf2 = malloc(sizeof(char) * bufsize);

        if ( buf1 == NULL || buf2 == NULL )
        {
                printf("Error, cannot malloc enough space for the test\n");
                exit(1);
        }

        memset((void*) buf1, 'A', bufsize);

        gettimeofday(&start_tv, NULL);
        for ( lcv = 0; lcv < numiter; lcv++ )
        {
                memcpy(buf2, buf1, bufsize);
                memcpy(buf1, buf2, bufsize);
        }
        gettimeofday(&end_tv, NULL);
        delta = end_tv.tv_sec - start_tv.tv_sec +
                ( end_tv.tv_usec - start_tv.tv_usec ) / 1000000.0;

        printf("memcpy took %f seconds\n", delta);

        gettimeofday(&start_tv, NULL);
        for ( lcv = 0; lcv < numiter; lcv++ )
        {
                memmove(buf2, buf1, bufsize);
                memmove(buf1, buf2, bufsize);
        }
        gettimeofday(&end_tv, NULL);
        delta = end_tv.tv_sec - start_tv.tv_sec +
                ( end_tv.tv_usec - start_tv.tv_usec ) / 1000000.0;

        printf("memmove took %f seconds\n", delta);

        return 0;
}