mirror of
https://github.com/servalproject/serval-dna.git
synced 2024-12-30 01:48:54 +00:00
104 lines
2.7 KiB
C
104 lines
2.7 KiB
C
|
|
/*******************************************************************************
|
|
* 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
|
|
* ben@bytepb.byte.com rick_g@bytepb.byte.com tyager@bytepb.byte.com
|
|
*
|
|
*******************************************************************************
|
|
* 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 <kahn@zk3.dec.com>
|
|
*
|
|
******************************************************************************/
|
|
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;
|
|
int stop_timing=0;
|
|
|
|
void report()
|
|
{
|
|
fprintf(stderr, "%lu context switches per second.\n", iter);
|
|
stop_timing=1;
|
|
}
|
|
|
|
void context_switch_test(int duration)
|
|
{
|
|
unsigned long check;
|
|
int p1[2], p2[2];
|
|
|
|
|
|
/* 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 (!stop_timing) {
|
|
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 (!stop_timing) {
|
|
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++;
|
|
}
|
|
}
|
|
}
|