Repo created

TMessagesProj/jni/voip/webrtc/base/android/jni_weak_ref.h

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+// 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 <jni.h>
+
+#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<jobject>& obj);
+  virtual ~JavaObjectWeakGlobalRef();
+
+  void operator=(const JavaObjectWeakGlobalRef& rhs);
+  void operator=(JavaObjectWeakGlobalRef&& rhs);
+
+  base::android::ScopedJavaLocalRef<jobject> 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<jobject> GetRealObject(
+    JNIEnv* env, jweak obj);
+
+#endif  // BASE_ANDROID_JNI_WEAK_REF_H_