stagger test

hmm.c

#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <time.h>

#define PROCS 10

int child(int n)
{
	while (1) {
		time_t tt;
		time(&tt);

		struct tm *tmi = localtime(&tt);
		char buffer[64];
		strftime(buffer, sizeof(buffer), "%FT%T", tmi);

		printf("%d %s\n", n, buffer);
		fflush(stdout);

		for (volatile unsigned long k=0; k<10000; ++k)
			for (volatile unsigned long j=0; j<1000; ++j)
				for (volatile unsigned long i=0; i<1000; ++i);

		sleep(10);
	}
}

int main(void)
{
	for (int i=0; i<PROCS; ++i) {
		pid_t pid = fork();
		if (pid == 0) {
			return child(i);
		}
	}

	while (1) {
		sleep(1);
	}
}


/*
$ gcc -Wall -std=gnu11 hmm.c && ./a.out | tee hmm.txt
$ gnuplot <<EOF >hmm.png
set terminal png size 960,540
set xdata time
set timefmt "%Y-%m-%dT%H:%M:%S"
plot "hmm.txt" using 2:(1) with points
EOF
*/