void update_process_group()

in OpsWorks/sample-cookbooks/cpulimit-ruby/files/default/cpulimit-master/src/process_group.c [119:187]

• 58 lines of code
• 7 McCabe index (conditional complexity)

void update_process_group(struct process_group *pgroup)
{
	struct process_iterator it;
	struct process tmp_process;
	struct process_filter filter;
	struct timeval now;
	gettimeofday(&now, NULL);
	//time elapsed from previous sample (in ms)
	long dt = timediff(&now, &pgroup->last_update) / 1000;
	filter.pid = pgroup->target_pid;
	filter.include_children = pgroup->include_children;
	init_process_iterator(&it, &filter);
	clear_list(pgroup->proclist);
	init_list(pgroup->proclist, 4);

	while (get_next_process(&it, &tmp_process) != -1)
	{
//		struct timeval t;
//		gettimeofday(&t, NULL);
//		printf("T=%ld.%ld PID=%d PPID=%d START=%d CPUTIME=%d\n", t.tv_sec, t.tv_usec, tmp_process.pid, tmp_process.ppid, tmp_process.starttime, tmp_process.cputime);
		int hashkey = pid_hashfn(tmp_process.pid);
		if (pgroup->proctable[hashkey] == NULL)
		{
			//empty bucket
			pgroup->proctable[hashkey] = malloc(sizeof(struct list));
			struct process *new_process = malloc(sizeof(struct process));
			tmp_process.cpu_usage = -1;
			memcpy(new_process, &tmp_process, sizeof(struct process));
			init_list(pgroup->proctable[hashkey], 4);
			add_elem(pgroup->proctable[hashkey], new_process);
			add_elem(pgroup->proclist, new_process);
		}
		else
		{
			//existing bucket
			struct process *p = (struct process*)locate_elem(pgroup->proctable[hashkey], &tmp_process);
			if (p == NULL)
			{
				//process is new. add it
				struct process *new_process = malloc(sizeof(struct process));
				tmp_process.cpu_usage = -1;
				memcpy(new_process, &tmp_process, sizeof(struct process));
				add_elem(pgroup->proctable[hashkey], new_process);
				add_elem(pgroup->proclist, new_process);
			}
			else
			{
				assert(tmp_process.pid == p->pid);
				assert(tmp_process.starttime == p->starttime);
				add_elem(pgroup->proclist, p);
				if (dt < MIN_DT) continue;
				//process exists. update CPU usage
				double sample = 1.0 * (tmp_process.cputime - p->cputime) / dt;
				if (p->cpu_usage == -1) {
					//initialization
					p->cpu_usage = sample;
				}
				else {
					//usage adjustment
					p->cpu_usage = (1.0-ALFA) * p->cpu_usage + ALFA * sample;
				}
				p->cputime = tmp_process.cputime;
			}
		}
	}
	close_process_iterator(&it);
	if (dt < MIN_DT) return;
	pgroup->last_update = now;
}