unplugged-system/system/memory/lmkd/include/lmkd_hooks.h

68 lines
2.1 KiB
C

/*
* Copyright 2022 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.
*/
/*
* This file defines no-op hook functions for LMKD. To override these
* definitions, enable the use_lmkd_hooks product variable and create a library
* "liblmkdhooks" that supplies definitions for the hook functions in your
* vendor folder.
*/
#ifndef _LMKD_HOOKS_H_
#define _LMKD_HOOKS_H_
#include <sys/types.h>
__BEGIN_DECLS
#ifdef LMKD_USE_HOOKS
/*
* Initialize all necessary Android props and perform any necessary validation
* on the values. Called before lmkd_init_hook() and will be called again
* whenever LMKD receives the LMK_UPDATE_PROPS command. Returns true on success,
* false otherwise.
*/
bool lmkd_update_props_hook();
/*
* Perform any necessary initialization for the hooks. Called only once at the
* end of LMKD's init(). Returns true on success, false otherwise.
*/
bool lmkd_init_hook();
/*
* Allows for interception of a kill by LMKD. This hook may attempt to free
* memory elsewhere to avoid the specified process being killed. Returns 0 to
* proceed with the kill, or the number of memory pages freed elsewhere to skip
* the kill.
*/
int lmkd_free_memory_before_kill_hook(struct proc* procp, int proc_size_pages,
int proc_oom_score, int kill_reason);
#else /* LMKD_USE_HOOKS */
static inline bool lmkd_update_props_hook() { return true; }
static inline bool lmkd_init_hook() { return true; }
static inline int lmkd_free_memory_before_kill_hook(struct proc*, int, int,
int) {
return 0;
}
#endif /* LMKD_USE_HOOKS */
__END_DECLS
#endif