summaryrefslogtreecommitdiffstats
path: root/Documentation/cgroups/cgroup_event_listener.c
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation/cgroups/cgroup_event_listener.c')
-rw-r--r--Documentation/cgroups/cgroup_event_listener.c110
1 files changed, 0 insertions, 110 deletions
diff --git a/Documentation/cgroups/cgroup_event_listener.c b/Documentation/cgroups/cgroup_event_listener.c
deleted file mode 100644
index 3e082f9..0000000
--- a/Documentation/cgroups/cgroup_event_listener.c
+++ /dev/null
@@ -1,110 +0,0 @@
-/*
- * cgroup_event_listener.c - Simple listener of cgroup events
- *
- * Copyright (C) Kirill A. Shutemov <kirill@shutemov.name>
- */
-
-#include <assert.h>
-#include <errno.h>
-#include <fcntl.h>
-#include <libgen.h>
-#include <limits.h>
-#include <stdio.h>
-#include <string.h>
-#include <unistd.h>
-
-#include <sys/eventfd.h>
-
-#define USAGE_STR "Usage: cgroup_event_listener <path-to-control-file> <args>\n"
-
-int main(int argc, char **argv)
-{
- int efd = -1;
- int cfd = -1;
- int event_control = -1;
- char event_control_path[PATH_MAX];
- char line[LINE_MAX];
- int ret;
-
- if (argc != 3) {
- fputs(USAGE_STR, stderr);
- return 1;
- }
-
- cfd = open(argv[1], O_RDONLY);
- if (cfd == -1) {
- fprintf(stderr, "Cannot open %s: %s\n", argv[1],
- strerror(errno));
- goto out;
- }
-
- ret = snprintf(event_control_path, PATH_MAX, "%s/cgroup.event_control",
- dirname(argv[1]));
- if (ret >= PATH_MAX) {
- fputs("Path to cgroup.event_control is too long\n", stderr);
- goto out;
- }
-
- event_control = open(event_control_path, O_WRONLY);
- if (event_control == -1) {
- fprintf(stderr, "Cannot open %s: %s\n", event_control_path,
- strerror(errno));
- goto out;
- }
-
- efd = eventfd(0, 0);
- if (efd == -1) {
- perror("eventfd() failed");
- goto out;
- }
-
- ret = snprintf(line, LINE_MAX, "%d %d %s", efd, cfd, argv[2]);
- if (ret >= LINE_MAX) {
- fputs("Arguments string is too long\n", stderr);
- goto out;
- }
-
- ret = write(event_control, line, strlen(line) + 1);
- if (ret == -1) {
- perror("Cannot write to cgroup.event_control");
- goto out;
- }
-
- while (1) {
- uint64_t result;
-
- ret = read(efd, &result, sizeof(result));
- if (ret == -1) {
- if (errno == EINTR)
- continue;
- perror("Cannot read from eventfd");
- break;
- }
- assert(ret == sizeof(result));
-
- ret = access(event_control_path, W_OK);
- if ((ret == -1) && (errno == ENOENT)) {
- puts("The cgroup seems to have removed.");
- ret = 0;
- break;
- }
-
- if (ret == -1) {
- perror("cgroup.event_control "
- "is not accessible any more");
- break;
- }
-
- printf("%s %s: crossed\n", argv[1], argv[2]);
- }
-
-out:
- if (efd >= 0)
- close(efd);
- if (event_control >= 0)
- close(event_control);
- if (cfd >= 0)
- close(cfd);
-
- return (ret != 0);
-}