1 /* 2 * Copyright (C) 2010 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 SCOPED_LOCAL_REF_H_included 18 #define SCOPED_LOCAL_REF_H_included 19 20 #include "jni.h" 21 22 #include <stddef.h> 23 24 // A smart pointer that deletes a JNI local reference when it goes out of scope. 25 template<typename T> 26 class ScopedLocalRef { 27 public: 28 ScopedLocalRef(JNIEnv* env, T localRef) : mEnv(env), mLocalRef(localRef) { 29 } 30 31 ~ScopedLocalRef() { 32 reset(); 33 } 34 35 void reset(T ptr = NULL) { 36 if (ptr != mLocalRef) { 37 if (mLocalRef != NULL) { 38 mEnv->DeleteLocalRef(mLocalRef); 39 } 40 mLocalRef = ptr; 41 } 42 } 43 44 T release() __attribute__((warn_unused_result)) { 45 T localRef = mLocalRef; 46 mLocalRef = NULL; 47 return localRef; 48 } 49 50 T get() const { 51 return mLocalRef; 52 } 53 54 private: 55 JNIEnv* mEnv; 56 T mLocalRef; 57 58 // Disallow copy and assignment. 59 ScopedLocalRef(const ScopedLocalRef&); 60 void operator=(const ScopedLocalRef&); 61 }; 62 63 #endif // SCOPED_LOCAL_REF_H_included 64
