platform_system_core/lmkd/liblmkd_utils.c
Suren Baghdasaryan 0f10051805 lmkd: Introduce liblmkd_utils for communicating with lmkd process
A number of tools and tests require communication with lmkd.
In order to avoid code duplication liblmkd_utils implements
functions commonly used when interacting with lmkd process.
Isolate communication protocol details into lmkd.h

Bug: 63631020

Change-Id: Id840983d55b7db60013d52dee0c3187943811822
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
2018-01-31 18:10:49 +00:00

76 lines
2.1 KiB
C

/*
* Copyright 2018 Google, Inc
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <errno.h>
#include <fcntl.h>
#include <sys/cdefs.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <stdio.h>
#include <unistd.h>
#include <liblmkd_utils.h>
#include <cutils/sockets.h>
int lmkd_connect() {
return socket_local_client("lmkd",
ANDROID_SOCKET_NAMESPACE_RESERVED,
SOCK_SEQPACKET);
}
int lmkd_register_proc(int sock, struct lmk_procprio *params) {
LMKD_CTRL_PACKET packet;
size_t size;
int ret;
size = lmkd_pack_set_procprio(packet, params);
ret = TEMP_FAILURE_RETRY(write(sock, packet, size));
return (ret < 0) ? -1 : 0;
}
int create_memcg(uid_t uid, pid_t pid) {
char buf[256];
int tasks_file;
int written;
snprintf(buf, sizeof(buf), "/dev/memcg/apps/uid_%u", uid);
if (mkdir(buf, S_IRWXU | S_IRWXG | S_IROTH | S_IXOTH) < 0 &&
errno != EEXIST) {
return -1;
}
snprintf(buf, sizeof(buf), "/dev/memcg/apps/uid_%u/pid_%u", uid, pid);
if (mkdir(buf, S_IRWXU | S_IRWXG | S_IROTH | S_IXOTH) < 0 &&
errno != EEXIST) {
return -1;
}
snprintf(buf, sizeof(buf), "/dev/memcg/apps/uid_%u/pid_%u/tasks", uid, pid);
tasks_file = open(buf, O_WRONLY);
if (tasks_file < 0) {
return -2;
}
written = snprintf(buf, sizeof(buf), "%u", pid);
if (__predict_false(written >= (int)sizeof(buf))) {
written = sizeof(buf) - 1;
}
written = TEMP_FAILURE_RETRY(write(tasks_file, buf, written));
close(tasks_file);
return (written < 0) ? -3 : 0;
}