#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/stat.h>
#include <stdbool.h>
#include <stdatomic.h>
#include <pthread.h>

#define DATA_LEN	65536
static unsigned char data[DATA_LEN];
#define SECONDS		10

static atomic_bool done = false;

static void *job(void *np)
{
	unsigned long iter = 0;
	int n = (int)np;
	char fn[64];
	sprintf(fn, "md-%d", n);
	mkdir(fn, 0755);
	strcat(fn, "/file.txt");
	while (!done) {
		int h = creat(fn, 0644);
		if (h < 0) perror("creat"), exit(1);
		if (write(h, data, DATA_LEN) != DATA_LEN) perror("write"), exit(1);
		if (close(h)) perror("close"), exit(1);
		if (unlink(fn)) perror("unlink"), exit(1);
		iter++;
	}
	sprintf(fn, "md-%d", n);
	if (rmdir(fn)) perror("rmdir"), exit(1);
	return (void *)iter;
}

int main(int argc, char *argv[])
{
	int jobs, i;
	pthread_t *pths;
	unsigned long total;
	if (argc != 3) fprintf(stderr, "args\n"), exit(1);
	if (chdir(argv[1])) perror("chdir"), exit(1);
	jobs = atoi(argv[2]);
	pths = alloca(jobs * sizeof(pthread_t));
	for (i = 0; i < jobs; i++) {
		int e = pthread_create(&pths[i], NULL, job, (void *)i);
		if (e) errno = e, perror("pthread_create"), exit(1);
	}

	sleep(SECONDS);

	done = true;

	total = 0;
	for (i = 0; i < jobs; i++) {
		void *iter;
		int e = pthread_join(pths[i], &iter);
		if (e) errno = e, perror("pthread_join"), exit(1);
		total += (unsigned long)iter;
	}
	printf("%lu\n", total / SECONDS);
	return 0;
}