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/*******************************************************************************
* The BYTE UNIX Benchmarks - Release 3
* Module: context1.c SID: 3.3 5/15/91 19:30:18
*
*******************************************************************************
* Bug reports, patches, comments, suggestions should be sent to:
*
* Ben Smith, Rick Grehan or Tom Yager
* [email protected] [email protected] [email protected]
*
*******************************************************************************
* Modification Log:
* $Header: context1.c,v 3.4 87/06/22 14:22:59 kjmcdonell Beta $
* August 28, 1990 - changed timing routines--now returns total number of
* iterations in specified time period
* October 22, 1997 - code cleanup to remove ANSI C compiler warnings
* Andy Kahn <[email protected]>
*
******************************************************************************/
char SCCSid[] = "@(#) @(#)context1.c:3.3 -- 5/15/91 19:30:18";
/*
* Context switching via synchronized unbuffered pipe i/o
*
*/
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include "timeit.c"
unsigned long iter;
void report()
{
fprintf(stderr, "COUNT|%lu|1|lps\n", iter);
exit(0);
}
int main(argc, argv)
int argc;
char *argv[];
{
int duration;
unsigned long check;
int p1[2], p2[2];
if (argc != 2) {
fprintf(stderr, "Usage: context duration\n");
exit(1);
}
duration = atoi(argv[1]);
/* set up alarm call */
iter = 0;
wake_me(duration, report);
if (pipe(p1) || pipe(p2)) {
perror("pipe create failed");
exit(1);
}
if (fork()) { /* parent process */
/* master, write p1 & read p2 */
close(p1[0]); close(p2[1]);
while (1) {
if (write(p1[1], (char *)&iter, sizeof(iter)) != sizeof(iter)) {
if ((errno != 0) && (errno != EINTR))
perror("master write failed");
exit(1);
}
if (read(p2[0], (char *)&check, sizeof(check)) != sizeof(check)) {
if ((errno != 0) && (errno != EINTR))
perror("master read failed");
exit(1);
}
if (check != iter) {
fprintf(stderr, "Master sync error: expect %lu, got %lu\n",
iter, check);
exit(2);
}
iter++;
}
}
else { /* child process */
unsigned long iter1;
iter1 = 0;
/* slave, read p1 & write p2 */
close(p1[1]); close(p2[0]);
while (1) {
if (read(p1[0], (char *)&check, sizeof(check)) != sizeof(check)) {
if ((errno != 0) && (errno != EINTR))
perror("slave read failed");
exit(1);
}
if (check != iter1) {
fprintf(stderr, "Slave sync error: expect %lu, got %lu\n",
iter, check);
exit(2);
}
if (write(p2[1], (char *)&iter1, sizeof(iter1)) != sizeof(check)) {
if ((errno != 0) && (errno != EINTR))
perror("slave write failed");
exit(1);
}
iter1++;
}
}
}
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