1// Copyright (c) 2012 The Chromium Authors. All rights reserved. 2// Use of this source code is governed by a BSD-style license that can be 3// found in the LICENSE file. 4 5#ifndef BASE_ANDROID_JNI_HELPER_H_ 6#define BASE_ANDROID_JNI_HELPER_H_ 7 8#include <jni.h> 9 10#include "base/base_export.h" 11#include "base/android/scoped_java_ref.h" 12 13// Manages WeakGlobalRef lifecycle. 14// This class is not thread-safe w.r.t. get() and reset(). Multiple threads may 15// safely use get() concurrently, but if the user calls reset() (or of course, 16// calls the destructor) they'll need to provide their own synchronization. 17class BASE_EXPORT JavaObjectWeakGlobalRef { 18 public: 19 JavaObjectWeakGlobalRef(); 20 JavaObjectWeakGlobalRef(const JavaObjectWeakGlobalRef& orig); 21 JavaObjectWeakGlobalRef(JNIEnv* env, jobject obj); 22 virtual ~JavaObjectWeakGlobalRef(); 23 24 void operator=(const JavaObjectWeakGlobalRef& rhs); 25 26 base::android::ScopedJavaLocalRef<jobject> get(JNIEnv* env) const; 27 28 void reset(); 29 30 private: 31 void Assign(const JavaObjectWeakGlobalRef& rhs); 32 33 jweak obj_; 34}; 35 36// Get the real object stored in the weak reference returned as a 37// ScopedJavaLocalRef. 38BASE_EXPORT base::android::ScopedJavaLocalRef<jobject> GetRealObject( 39 JNIEnv* env, jweak obj); 40 41#endif // BASE_ANDROID_JNI_HELPER_H_ 42