aboutsummaryrefslogtreecommitdiffstats
path: root/src/process_group.c
blob: 06d73a6f3541c074266ec3ce3feea64e4ae68397 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
/**
 *
 * cpulimit - a CPU limiter for Linux
 *
 * Copyright (C) 2005-2012, by:  Angelo Marletta <angelo dot marletta at gmail dot com> 
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */

#include <string.h>
#include <stdlib.h>
#include <limits.h>
#include <sys/time.h>
#include <signal.h>

#include <assert.h>

#include "process_iterator.h"
#include "process_group.h"
#include "list.h"

// look for a process by pid
// search_pid   : pid of the wanted process
// return:  pid of the found process, if successful
//          negative pid, if the process does not exist or if the signal fails
int find_process_by_pid(pid_t pid)
{
	return (kill(pid,0)==0) ? pid : -pid;
}

// look for a process with a given name
// process: the name of the wanted process. it can be an absolute path name to the executable file
//         or just the file name
// return:  pid of the found process, if it is found
//         0, if it's not found
//         negative pid, if it is found but it's not possible to control it
int find_process_by_name(const char *process_name)
{
	//pid of the target process
	pid_t pid = -1;

	//process iterator
	struct process_iterator it;
	struct process proc;
	struct process_filter filter;
	filter.pid = 0;
	filter.include_children = 0;
	init_process_iterator(&it, &filter);
	while (get_next_process(&it, &proc) != -1)
	{
		//process found
		if (strncmp(basename(proc.command), process_name, strlen(process_name))==0 && kill(pid,SIGCONT)==0) {
			//process is ok!
			pid = proc.pid;
			break;
		}
	}
	if (close_process_iterator(&it) != 0) exit(1);
	if (pid >= 0) {
		//ok, the process was found
		return pid;
	}
	else {
		//process not found
		return 0;
	}
}

int init_process_group(struct process_group *pgroup, int target_pid, int include_children)
{
	//hashtable initialization
	memset(&pgroup->proctable, 0, sizeof(pgroup->proctable));
	pgroup->target_pid = target_pid;
	pgroup->include_children = include_children;
	pgroup->proclist = (struct list*)malloc(sizeof(struct list));
	init_list(pgroup->proclist, 4);
	memset(&pgroup->last_update, 0, sizeof(pgroup->last_update));
	update_process_group(pgroup);
	return 0;
}

int close_process_group(struct process_group *pgroup)
{
	int i;
	int size = sizeof(pgroup->proctable) / sizeof(struct process*);
	for (i=0; i<size; i++) {
		if (pgroup->proctable[i] != NULL) {
			//free() history for each process
			destroy_list(pgroup->proctable[i]);
			free(pgroup->proctable[i]);
			pgroup->proctable[i] = NULL;
		}
	}
	clear_list(pgroup->proclist);
	free(pgroup->proclist);
	pgroup->proclist = NULL;
	return 0;
}

void remove_terminated_processes(struct process_group *pgroup)
{
	//TODO
}

//return t1-t2 in microseconds (no overflow checks, so better watch out!)
static inline unsigned long timediff(const struct timeval *t1,const struct timeval *t2)
{
	return (t1->tv_sec - t2->tv_sec) * 1000000 + (t1->tv_usec - t2->tv_usec);
}

//parameter in range 0-1
#define ALFA 0.08
#define MIN_DT 20

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;
}

int remove_process(struct process_group *pgroup, int pid)
{
	int hashkey = pid_hashfn(pid);
	if (pgroup->proctable[hashkey] == NULL) return 1; //nothing to delete
	struct list_node *node = (struct list_node*)locate_node(pgroup->proctable[hashkey], &pid);
	if (node == NULL) return 2;
	delete_node(pgroup->proctable[hashkey], node);
	return 0;
}
Un proyecto texto-plano.xyz