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/* ==== bench_pipe.c ============================================================
* Copyright (c) 1993 by Chris Provenzano, proven@athena.mit.edu
*
* Description : Benchmark reads of /dev/null. Gives a good aprox. of
* syscall times.
*
* 1.00 93/08/01 proven
* -Started coding this file.
*/
#include <sys/types.h>
#include <sys/time.h>
#include <stdio.h>
#include <fcntl.h>
#include <errno.h>
#define OK 0
#define NOTOK -1
/* ==========================================================================
* usage();
*/
void usage(void)
{
printf("bench_pipe [-d?] [-c count]\n");
errno = 0;
}
main(int argc, char **argv)
{
struct timeval starttime, endtime;
char buf[1];
int count = 1000;
int debug = 0;
int fd0[2];
int fd1[2];
int i;
char word[256];
/* Getopt variables. */
extern int optind, opterr;
extern char *optarg;
while ((word[0] = getopt(argc, argv, "c:d?")) != (char)EOF) {
switch (word[0]) {
case 'd':
debug++;
break;
case 'c':
count = atoi(optarg);
break;
case '?':
usage();
return(OK);
default:
usage();
return(NOTOK);
}
}
if ((pipe(fd0) < OK) || (pipe(fd1) < OK)) {
printf("Error: pipe\n");
exit(0);
}
switch (fork()) {
case NOTOK:
printf("Error: fork\n");
exit(0);
case OK: /* Child */
for (i = 0; i < count; i++) {
if (read(fd1[0], buf, 1) < OK) {
printf("Error: child read\n");
exit(0);
}
if (write(fd0[1], buf, 1) < OK) {
printf("Error: child write\n");
exit(0);
}
}
exit(0);
break;
default:
break;
}
if (gettimeofday(&starttime, NULL)) {
printf("Error: gettimeofday\n");
exit(0);
}
count --;
if (write(fd1[1], buf, 1) < OK) {
perror("first parent write");
exit(0);
}
for (i = 0; i < count; i++) {
if (read(fd0[0], buf, 1) < OK) {
printf("Error: parent read\n");
exit(0);
}
if (write(fd1[1], buf, 1) < OK) {
printf("Error: parent write\n");
exit(0);
}
}
if (gettimeofday(&endtime, NULL)) {
printf("Error: gettimeofday\n");
exit(0);
}
printf("%d ping pong tests took %d usecs.\n", count,
(endtime.tv_sec - starttime.tv_sec) * 1000000 +
(endtime.tv_usec - starttime.tv_usec));
}
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