From 2bd70518410ccd6a25adc876a3619d0b23f92e5a Mon Sep 17 00:00:00 2001
From: LoveSy <shana@zju.edu.cn>
Date: Tue, 15 Mar 2022 19:01:32 +0800
Subject: [PATCH] Add JNIMonitor

---
 lsplant/src/main/jni/include/utils/jni_helper.hpp | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/lsplant/src/main/jni/include/utils/jni_helper.hpp b/lsplant/src/main/jni/include/utils/jni_helper.hpp
index ce88c26..e1f9a8b 100644
--- a/lsplant/src/main/jni/include/utils/jni_helper.hpp
+++ b/lsplant/src/main/jni/include/utils/jni_helper.hpp
@@ -96,12 +96,24 @@ class ScopedLocalRef<T>;
 class JNIScopeFrame {
     JNIEnv *env_;
 
+    DISALLOW_COPY_AND_ASSIGN(JNIScopeFrame);
 public:
     JNIScopeFrame(JNIEnv *env, jint size) : env_(env) { env_->PushLocalFrame(size); }
 
     ~JNIScopeFrame() { env_->PopLocalFrame(nullptr); }
 };
 
+class JNIMonitor {
+    JNIEnv *env_;
+    jobject obj_;
+
+    DISALLOW_COPY_AND_ASSIGN(JNIMonitor);
+public:
+    JNIMonitor(JNIEnv *env, jobject obj) : env_(env), obj_(obj) { env_->MonitorEnter(obj_); }
+
+    ~JNIMonitor() { env_->MonitorExit(obj_); }
+};
+
 template <typename T, typename U>
 concept ScopeOrRaw = std::is_convertible_v<T, U> ||
     (is_instance_v<std::decay_t<T>, ScopedLocalRef>
@@ -902,7 +914,7 @@ public:
 
     explicit ScopedLocalRef(JNIEnv *env) noexcept : ScopedLocalRef(env, T{nullptr}) {}
 
-    ~ScopedLocalRef() { release(); }
+    ~ScopedLocalRef() { env_->DeleteLocalRef(release()); }
 
     void reset(T ptr = nullptr) {
         if (ptr != local_ref_) {