add suport for measuring process resource usage

Signed-off-by: John Crispin <blogic@openwrt.org>

1 files changed, 99 insertions, 0 deletions

diff --git a/measure.c b/measure.c
new file mode 100644
index 0000000..9e21a66
--- /dev/null
+++ b/measure.c
@@ -0,0 +1,99 @@
+/**
+ *   Copyright (C) 2010 Steven Barth <steven@midlink.org>
+ *   Copyright (C) 2013 John Crispin <blogic@openwrt.org>
+ *
+ *   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., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
+ *
+ */
+
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <stdint.h>
+#include <ctype.h>
+#include <fcntl.h>
+#include <regex.h>
+#include <stdio.h>
+#include <string.h>
+#include <glob.h>
+#include <libgen.h>
+
+#include "procd.h"
+
+static regex_t pat_vmsize, pat_ppid, pat_state, pat_uid;
+
+static void __attribute__((constructor)) measure_init() {
+	regcomp(&pat_vmsize, "VmSize:[ \t]*([0-9]*) kB", REG_EXTENDED);
+	regcomp(&pat_uid, "Uid:[ \t]*([0-9]*).*", REG_EXTENDED);
+	regcomp(&pat_ppid, "PPid:[ \t]*([0-9]+)", REG_EXTENDED);
+	regcomp(&pat_state, "State:[ \t]*([A-Z])", REG_EXTENDED);
+}
+
+static void __attribute__((destructor)) measure_fini() {
+	regfree(&pat_vmsize);
+	regfree(&pat_ppid);
+	regfree(&pat_uid);
+	regfree(&pat_state);
+}
+
+int measure_process(pid_t pid, struct pid_info *pi) {
+	int fd;
+	char buffer[512] = "";
+	ssize_t rxed;
+	regmatch_t matches[2];
+	glob_t gl;
+	int i;
+
+	memset(pi, 0, sizeof(*pi));
+
+	snprintf(buffer, sizeof(buffer), "/proc/%i/fd/*", (int)pid);
+
+	if (glob(buffer, GLOB_NOESCAPE | GLOB_MARK, NULL, &gl)) {
+		fprintf(stderr, "glob failed on %s\n", buffer);
+		return -1;
+	}
+
+	for (i = 0; i < gl.gl_pathc; i++)
+		if (isdigit(basename(gl.gl_pathv[i])[0]))
+			pi->fdcount++;
+	globfree(&gl);
+
+	snprintf(buffer, sizeof(buffer), "/proc/%i/status", (int)pid);
+	fd = open(buffer, O_RDONLY);
+	if (fd == -1)
+		return -1;
+
+	rxed = read(fd, buffer, sizeof(buffer) - 1);
+	close(fd);
+	if (rxed == -1)
+		return -1;
+
+	buffer[rxed] = 0;
+
+	if (!regexec(&pat_state, buffer, 2, matches, 0))
+		pi->stat = buffer[matches[1].rm_so];
+
+	if (!regexec(&pat_ppid, buffer, 2, matches, 0))
+		pi->ppid = atoi(buffer + matches[1].rm_so);
+
+	if (!regexec(&pat_uid, buffer, 2, matches, 0))
+		pi->uid = atoi(buffer + matches[1].rm_so);
+
+	if (!regexec(&pat_vmsize, buffer, 2, matches, 0))
+		pi->vmsize = atoi(buffer + matches[1].rm_so) * 1024;
+
+	return 0;
+}