// Copyright 2014 The Chromium Authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. #ifndef BASE_ANDROID_JNI_WEAK_REF_H_ #define BASE_ANDROID_JNI_WEAK_REF_H_ #include #include "base/android/scoped_java_ref.h" #include "base/base_export.h" // Manages WeakGlobalRef lifecycle. // This class is not thread-safe w.r.t. get() and reset(). Multiple threads may // safely use get() concurrently, but if the user calls reset() (or of course, // calls the destructor) they'll need to provide their own synchronization. class BASE_EXPORT JavaObjectWeakGlobalRef { public: JavaObjectWeakGlobalRef(); JavaObjectWeakGlobalRef(const JavaObjectWeakGlobalRef& orig); JavaObjectWeakGlobalRef(JavaObjectWeakGlobalRef&& orig) noexcept; JavaObjectWeakGlobalRef(JNIEnv* env, jobject obj); JavaObjectWeakGlobalRef(JNIEnv* env, const base::android::JavaRef& obj); virtual ~JavaObjectWeakGlobalRef(); void operator=(const JavaObjectWeakGlobalRef& rhs); void operator=(JavaObjectWeakGlobalRef&& rhs); base::android::ScopedJavaLocalRef get(JNIEnv* env) const; // Returns true if the weak reference has not been initialized to point at // an object (or ḣas had reset() called). // Do not call this to test if the object referred to still exists! The weak // reference remains initialized even if the target object has been collected. bool is_uninitialized() const { return obj_ == nullptr; } void reset(); private: void Assign(const JavaObjectWeakGlobalRef& rhs); jweak obj_; }; // Get the real object stored in the weak reference returned as a // ScopedJavaLocalRef. BASE_EXPORT base::android::ScopedJavaLocalRef GetRealObject( JNIEnv* env, jweak obj); #endif // BASE_ANDROID_JNI_WEAK_REF_H_