1 // Copyright 2014 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_WEAK_REF_H_ 6 #define BASE_ANDROID_JNI_WEAK_REF_H_ 7 8 #include <jni.h> 9 10 #include "base/android/scoped_java_ref.h" 11 #include "base/base_export.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. 17 class 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 is_empty()28 bool is_empty() const { return obj_ == NULL; } 29 30 void reset(); 31 32 private: 33 void Assign(const JavaObjectWeakGlobalRef& rhs); 34 35 jweak obj_; 36 }; 37 38 // Get the real object stored in the weak reference returned as a 39 // ScopedJavaLocalRef. 40 BASE_EXPORT base::android::ScopedJavaLocalRef<jobject> GetRealObject( 41 JNIEnv* env, jweak obj); 42 43 #endif // BASE_ANDROID_JNI_WEAK_REF_H_ 44