From: Daniel Lezcano <daniel.lezcano@free.fr>
Date: Thu, 8 Apr 2010 07:44:23 +0000 (+0200)
Subject: count the number of tasks in the container
X-Git-Tag: lxc-0.7.0~112
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e0f888d910c2680acf6267391f88ab75ef66771f;p=thirdparty%2Flxc.git

count the number of tasks in the container

This patch adds a function to count the number of tasks in the
container. The result is not reliable as it may change with a fork
or an exit, but in some cases, for example, there is only one task, or
the container is frozen, the result is accurate.

Signed-off-by: Daniel Lezcano <dlezcano@fr.ibm.com>
---

diff --git a/src/lxc/cgroup.c b/src/lxc/cgroup.c
index 55aa8b22f..cc57e71fc 100644
--- a/src/lxc/cgroup.c
+++ b/src/lxc/cgroup.c
@@ -219,3 +219,30 @@ int lxc_cgroup_get(const char *name, const char *subsystem,
 	close(fd);
 	return ret;
 }
+
+int lxc_cgroup_nrtasks(const char *name)
+{
+	char *nsgroup;
+	char path[MAXPATHLEN];
+	int pid, ret, count = 0;
+	FILE *file;
+
+	ret = lxc_cgroup_path_get(&nsgroup, name);
+	if (ret)
+		return -1;
+
+        snprintf(path, MAXPATHLEN, "%s/tasks", nsgroup);
+
+	file = fopen(path, "r");
+	if (!file) {
+		SYSERROR("fopen '%s' failed", path);
+		return -1;
+	}
+
+	while (fscanf(file, "%d", &pid) != EOF)
+		count++;
+
+	fclose(file);
+
+	return count;
+}
diff --git a/src/lxc/cgroup.h b/src/lxc/cgroup.h
index 88791bed8..640f1d245 100644
--- a/src/lxc/cgroup.h
+++ b/src/lxc/cgroup.h
@@ -29,5 +29,5 @@ struct lxc_handler;
 int lxc_rename_nsgroup(const char *name, struct lxc_handler *handler);
 int lxc_unlink_nsgroup(const char *name);
 int lxc_cgroup_path_get(char **path, const char *name);
-
+int lxc_cgroup_nrtasks(const char *name);
 #endif