| /* |
| * Copyright (C) 2019 The Android Open Source Project |
| * |
| * 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. |
| */ |
| |
| #define LOG_TAG "AppCompactor" |
| //#define LOG_NDEBUG 0 |
| |
| #include <dirent.h> |
| #include <stddef.h> |
| #include <stdio.h> |
| #include <sys/stat.h> |
| #include <sys/types.h> |
| #include <unistd.h> |
| |
| #include <android-base/stringprintf.h> |
| #include <android-base/file.h> |
| |
| #include <nativehelper/JNIHelp.h> |
| #include <android_runtime/AndroidRuntime.h> |
| #include <jni.h> |
| |
| using android::base::StringPrintf; |
| using android::base::WriteStringToFile; |
| |
| namespace android { |
| |
| // This performs per-process reclaim on all processes belonging to non-app UIDs. |
| // For the most part, these are non-zygote processes like Treble HALs, but it |
| // also includes zygote-derived processes that run in system UIDs, like bluetooth |
| // or potentially some mainline modules. The only process that should definitely |
| // not be compacted is system_server, since compacting system_server around the |
| // time of BOOT_COMPLETE could result in perceptible issues. |
| static void com_android_server_am_AppCompactor_compactSystem(JNIEnv *, jobject) { |
| std::unique_ptr<DIR, decltype(&closedir)> proc(opendir("/proc"), closedir); |
| struct dirent* current; |
| while ((current = readdir(proc.get()))) { |
| if (current->d_type != DT_DIR) { |
| continue; |
| } |
| |
| // don't compact system_server, rely on persistent compaction during screen off |
| // in order to avoid mmap_sem-related stalls |
| if (atoi(current->d_name) == getpid()) { |
| continue; |
| } |
| |
| std::string status_name = StringPrintf("/proc/%s/status", current->d_name); |
| struct stat status_info; |
| |
| if (stat(status_name.c_str(), &status_info) != 0) { |
| // must be some other directory that isn't a pid |
| continue; |
| } |
| |
| // android.os.Process.FIRST_APPLICATION_UID |
| if (status_info.st_uid >= 10000) { |
| continue; |
| } |
| |
| std::string reclaim_path = StringPrintf("/proc/%s/reclaim", current->d_name); |
| WriteStringToFile(std::string("all"), reclaim_path); |
| } |
| } |
| |
| static const JNINativeMethod sMethods[] = { |
| /* name, signature, funcPtr */ |
| {"compactSystem", "()V", (void*)com_android_server_am_AppCompactor_compactSystem}, |
| }; |
| |
| int register_android_server_am_AppCompactor(JNIEnv* env) |
| { |
| return jniRegisterNativeMethods(env, "com/android/server/am/AppCompactor", |
| sMethods, NELEM(sMethods)); |
| } |
| |
| } |