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diff --git a/src/rocksdb/java/rocksjni/jnicallback.cc b/src/rocksdb/java/rocksjni/jnicallback.cc
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+// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
+// This source code is licensed under both the GPLv2 (found in the
+// COPYING file in the root directory) and Apache 2.0 License
+// (found in the LICENSE.Apache file in the root directory).
+//
+// This file implements the callback "bridge" between Java and C++ for
+// JNI Callbacks from C++ to sub-classes or org.rocksdb.RocksCallbackObject
+
+#include "rocksjni/jnicallback.h"
+
+#include <assert.h>
+
+#include "rocksjni/portal.h"
+
+namespace ROCKSDB_NAMESPACE {
+JniCallback::JniCallback(JNIEnv* env, jobject jcallback_obj) {
+ // Note: jcallback_obj may be accessed by multiple threads,
+ // so we ref the jvm not the env
+ const jint rs = env->GetJavaVM(&m_jvm);
+ if (rs != JNI_OK) {
+ // exception thrown
+ return;
+ }
+
+ // Note: we may want to access the Java callback object instance
+ // across multiple method calls, so we create a global ref
+ assert(jcallback_obj != nullptr);
+ m_jcallback_obj = env->NewGlobalRef(jcallback_obj);
+ if (jcallback_obj == nullptr) {
+ // exception thrown: OutOfMemoryError
+ return;
+ }
+}
+
+JNIEnv* JniCallback::getJniEnv(jboolean* attached) const {
+ return JniUtil::getJniEnv(m_jvm, attached);
+}
+
+void JniCallback::releaseJniEnv(jboolean& attached) const {
+ JniUtil::releaseJniEnv(m_jvm, attached);
+}
+
+JniCallback::~JniCallback() {
+ jboolean attached_thread = JNI_FALSE;
+ JNIEnv* env = getJniEnv(&attached_thread);
+ assert(env != nullptr);
+
+ if (m_jcallback_obj != nullptr) {
+ env->DeleteGlobalRef(m_jcallback_obj);
+ }
+
+ releaseJniEnv(attached_thread);
+}
+} // namespace ROCKSDB_NAMESPACE