/* This file is part of genrc
Copyryght (C) 2018 Sergey Poznyakoff
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
*/
#include "genrc.h"

static void
timermul(struct timeval *a, int b)
{
	a->tv_sec *= b;
	a->tv_usec *= b;
	a->tv_sec = a->tv_sec + a->tv_usec / 1000000;
	a->tv_usec %= 1000000;
}

#define MIN_POLL_TTW 20000

int
com_stop(void)
{
	PIDLIST pids;
	struct timeval stoptime, before, after, ttw, maxttw;
	int ratio;
	
	pidlist_init(&pids);	
	if (get_pid_list(genrc_pid_closure, &pids)) {
		genrc_error("program status unknown");
		return 1;
	}

	if (pids.pidc == 0) {
		genrc_error("%s not running", genrc_program);
		return 1;
	}

	if (genrc_verbose)
		printf("Stopping %s\n", genrc_program);

	gettimeofday(&stoptime, NULL);
	stoptime.tv_sec += genrc_timeout;
	ratio = 1;
	while (pids.pidc) {
		gettimeofday(&before, NULL);
		if (timercmp(&before, &stoptime, >)) 
			break;
		pidlist_kill(&pids, genrc_signal_stop);
		if (get_pid_list(genrc_pid_closure, &pids))
			break;
		if (pids.pidc == 0)
			return 0;
		gettimeofday(&after, NULL);
		if (timercmp(&after, &stoptime, >=))
			break;
		if (ratio < 10)
			++ratio;
		timersub(&stoptime, &after, &maxttw);
		timersub(&after, &before, &ttw);
		timermul(&ttw, ratio);
		if (ttw.tv_sec < 0 || ttw.tv_usec < 0)
			ttw.tv_sec = ttw.tv_usec = 0;
		if (timercmp(&ttw, &maxttw, >))
			ttw = maxttw;
		if (ttw.tv_sec == 0 && ttw.tv_usec < MIN_POLL_TTW)
			ttw.tv_usec = MIN_POLL_TTW;
		if (select(0, NULL, NULL, NULL, &ttw) < 0 && errno != EINTR) {
			system_error(errno, "select");
			break;
		}
	}
	return 1;
}