1 /* 2 * Copyright 2018 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #ifndef JAVA_VM_HELPER_H_ 18 19 #define JAVA_VM_HELPER_H_ 20 21 #include "jni.h" 22 23 #include <atomic> 24 25 namespace android { 26 27 struct JavaVMHelper { 28 static JNIEnv *getJNIEnv(); 29 static JavaVM *getJavaVM(); 30 static void setJavaVM(JavaVM *vm); 31 32 private: 33 // Once a valid JavaVM has been set, it should never be reset or changed. 34 // However, as it may be accessed from multiple threads, access needs to be 35 // synchronized. 36 static std::atomic<JavaVM *> sJavaVM; 37 }; 38 39 } // namespace android 40 41 #endif // JAVA_VM_HELPER_H_ 42