openjdkjvmti/ti_field.cc - LeafOS-Project/android_art - Gitiles

 /* Copyright (C) 2016 The Android Open Source Project
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This file implements interfaces from the file jvmti.h. This implementation
  * is licensed under the same terms as the file jvmti.h.  The
  * copyright and license information for the file jvmti.h follows.
  *
  * Copyright (c) 2003, 2011, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.  Oracle designates this
  * particular file as subject to the "Classpath" exception as provided
  * by Oracle in the LICENSE file that accompanied this code.
  *
  * This code is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  */

 #include "ti_field.h"
 #include <unordered_map>

 #include "android-base/thread_annotations.h"
 #include "art_field-inl.h"
 #include "art_field.h"
 #include "art_jvmti.h"
 #include "base/enums.h"
 #include "base/locks.h"
 #include "dex/dex_file_annotations.h"
 #include "dex/modifiers.h"
 #include "jni/jni_internal.h"
 #include "mirror/object_array-inl.h"
 #include "reflective_value_visitor.h"
 #include "runtime.h"
 #include "runtime_callbacks.h"
 #include "scoped_thread_state_change-inl.h"
 #include "thread-current-inl.h"

 namespace openjdkjvmti {

 class JvmtiFieldReflectionSource : public art::ReflectionSourceInfo {
  public:
   JvmtiFieldReflectionSource(bool is_access, art::ArtField* f)
       : art::ReflectionSourceInfo(art::ReflectionSourceType::kSourceMiscInternal),
         is_access_(is_access),
         f_(f) {}
   void Describe(std::ostream& os) const override REQUIRES_SHARED(art::Locks::mutator_lock_) {
     art::ReflectionSourceInfo::Describe(os);
     os << " jvmti Field" << (is_access_ ? "Access" : "Modification")
        << "Watch Target=" << f_->PrettyField();
   }

  private:
   bool is_access_;
   art::ArtField* f_;
 };
 struct FieldReflectiveValueCallback : public art::ReflectiveValueVisitCallback {
  public:
   void VisitReflectiveTargets(art::ReflectiveValueVisitor* visitor)
       REQUIRES(art::Locks::mutator_lock_) {
     art::Thread* self = art::Thread::Current();
     event_handler->ForEachEnv(self, [&](ArtJvmTiEnv* env) NO_THREAD_SAFETY_ANALYSIS {
       art::Locks::mutator_lock_->AssertExclusiveHeld(self);
       art::WriterMutexLock mu(self, env->event_info_mutex_);
       std::vector<std::pair<art::ArtField*, art::ArtField*>> updated_access_fields;
       for (auto it : env->access_watched_fields) {
         art::ArtField* af =
             visitor->VisitField(it, JvmtiFieldReflectionSource(/*is_access=*/true, it));
         if (af != it) {
           updated_access_fields.push_back({ af, it });
         }
       }
       for (auto it : updated_access_fields) {
         DCHECK(env->access_watched_fields.find(it.second) != env->access_watched_fields.end());
         env->access_watched_fields.erase(it.second);
         env->access_watched_fields.insert(it.first);
       }
       std::vector<std::pair<art::ArtField*, art::ArtField*>> updated_modify_fields;
       for (auto it : env->modify_watched_fields) {
         art::ArtField* af =
             visitor->VisitField(it, JvmtiFieldReflectionSource(/*is_access=*/false, it));
         if (af != it) {
           updated_modify_fields.push_back({ af, it });
         }
       }
       for (auto it : updated_modify_fields) {
         DCHECK(env->modify_watched_fields.find(it.second) != env->modify_watched_fields.end());
         env->modify_watched_fields.erase(it.second);
         env->modify_watched_fields.insert(it.first);
       }
     });
   }

   EventHandler* event_handler = nullptr;
 };

 static FieldReflectiveValueCallback gReflectiveValueCallback;

 void FieldUtil::Register(EventHandler* eh) {
   gReflectiveValueCallback.event_handler = eh;
   art::ScopedThreadStateChange stsc(art::Thread::Current(),
                                     art::ThreadState::kWaitingForDebuggerToAttach);
   art::ScopedSuspendAll ssa("Add reflective value visit callback");
   art::RuntimeCallbacks* callbacks = art::Runtime::Current()->GetRuntimeCallbacks();
   callbacks->AddReflectiveValueVisitCallback(&gReflectiveValueCallback);
 }

 void FieldUtil::Unregister() {
   art::ScopedThreadStateChange stsc(art::Thread::Current(),
                                     art::ThreadState::kWaitingForDebuggerToAttach);
   art::ScopedSuspendAll ssa("Remove reflective value visit callback");
   art::RuntimeCallbacks* callbacks = art::Runtime::Current()->GetRuntimeCallbacks();
   callbacks->RemoveReflectiveValueVisitCallback(&gReflectiveValueCallback);
 }
 // Note: For all these functions, we could do a check that the field actually belongs to the given
 //       class. But the spec seems to assume a certain encoding of the field ID, and so doesn't
 //       specify any errors.

 jvmtiError FieldUtil::GetFieldName(jvmtiEnv* env,
                                    jclass klass,
                                    jfieldID field,
                                    char** name_ptr,
                                    char** signature_ptr,
                                    char** generic_ptr) {
   if (klass == nullptr) {
     return ERR(INVALID_CLASS);
   }
   if (field == nullptr) {
     return ERR(INVALID_FIELDID);
   }

   art::ScopedObjectAccess soa(art::Thread::Current());
   art::ArtField* art_field = art::jni::DecodeArtField(field);

   JvmtiUniquePtr<char[]> name_copy;
   if (name_ptr != nullptr) {
     const char* field_name = art_field->GetName();
     if (field_name == nullptr) {
       field_name = "<error>";
     }
     jvmtiError ret;
     name_copy = CopyString(env, field_name, &ret);
     if (name_copy == nullptr) {
       return ret;
     }
     *name_ptr = name_copy.get();
   }

   JvmtiUniquePtr<char[]> signature_copy;
   if (signature_ptr != nullptr) {
     const char* sig = art_field->GetTypeDescriptor();
     jvmtiError ret;
     signature_copy = CopyString(env, sig, &ret);
     if (signature_copy == nullptr) {
       return ret;
     }
     *signature_ptr = signature_copy.get();
   }

   if (generic_ptr != nullptr) {
     *generic_ptr = nullptr;
     if (!art_field->GetDeclaringClass()->IsProxyClass()) {
       art::ObjPtr<art::mirror::ObjectArray<art::mirror::String>> str_array =
           art::annotations::GetSignatureAnnotationForField(art_field);
       if (str_array != nullptr) {
         std::ostringstream oss;
         for (auto str : str_array->Iterate()) {
           oss << str->ToModifiedUtf8();
         }
         std::string output_string = oss.str();
         jvmtiError ret;
         JvmtiUniquePtr<char[]> copy = CopyString(env, output_string.c_str(), &ret);
         if (copy == nullptr) {
           return ret;
         }
         *generic_ptr = copy.release();
       } else if (soa.Self()->IsExceptionPending()) {
         // TODO: Should we report an error here?
         soa.Self()->ClearException();
       }
     }
   }

   // Everything is fine, release the buffers.
   name_copy.release();
   signature_copy.release();

   return ERR(NONE);
 }

 jvmtiError FieldUtil::GetFieldDeclaringClass([[maybe_unused]] jvmtiEnv* env,
                                              jclass klass,
                                              jfieldID field,
                                              jclass* declaring_class_ptr) {
   if (klass == nullptr) {
     return ERR(INVALID_CLASS);
   }
   if (field == nullptr) {
     return ERR(INVALID_FIELDID);
   }
   if (declaring_class_ptr == nullptr) {
     return ERR(NULL_POINTER);
   }

   art::ScopedObjectAccess soa(art::Thread::Current());
   art::ArtField* art_field = art::jni::DecodeArtField(field);
   art::ObjPtr<art::mirror::Class> field_klass = art_field->GetDeclaringClass();

   *declaring_class_ptr = soa.AddLocalReference<jclass>(field_klass);

   return ERR(NONE);
 }

 jvmtiError FieldUtil::GetFieldModifiers([[maybe_unused]] jvmtiEnv* env,
                                         jclass klass,
                                         jfieldID field,
                                         jint* modifiers_ptr) {
   if (klass == nullptr) {
     return ERR(INVALID_CLASS);
   }
   if (field == nullptr) {
     return ERR(INVALID_FIELDID);
   }
   if (modifiers_ptr == nullptr) {
     return ERR(NULL_POINTER);
   }

   art::ScopedObjectAccess soa(art::Thread::Current());
   art::ArtField* art_field = art::jni::DecodeArtField(field);
   // Note: Keep this code in sync with Field.getModifiers.
   uint32_t modifiers = art_field->GetAccessFlags() & 0xFFFF;

   *modifiers_ptr = modifiers;
   return ERR(NONE);
 }

 jvmtiError FieldUtil::IsFieldSynthetic([[maybe_unused]] jvmtiEnv* env,
                                        jclass klass,
                                        jfieldID field,
                                        jboolean* is_synthetic_ptr) {
   if (klass == nullptr) {
     return ERR(INVALID_CLASS);
   }
   if (field == nullptr) {
     return ERR(INVALID_FIELDID);
   }
   if (is_synthetic_ptr == nullptr) {
     return ERR(NULL_POINTER);
   }

   art::ScopedObjectAccess soa(art::Thread::Current());
   art::ArtField* art_field = art::jni::DecodeArtField(field);
   uint32_t modifiers = art_field->GetAccessFlags();

   *is_synthetic_ptr = ((modifiers & art::kAccSynthetic) != 0) ? JNI_TRUE : JNI_FALSE;
   return ERR(NONE);
 }

 jvmtiError FieldUtil::SetFieldModificationWatch(jvmtiEnv* jenv, jclass klass, jfieldID field) {
   ArtJvmTiEnv* env = ArtJvmTiEnv::AsArtJvmTiEnv(jenv);
   art::WriterMutexLock lk(art::Thread::Current(), env->event_info_mutex_);
   if (klass == nullptr) {
     return ERR(INVALID_CLASS);
   }
   if (field == nullptr) {
     return ERR(INVALID_FIELDID);
   }
   auto res_pair = env->modify_watched_fields.insert(art::jni::DecodeArtField(field));
   if (!res_pair.second) {
     // Didn't get inserted because it's already present!
     return ERR(DUPLICATE);
   }
   return OK;
 }

 jvmtiError FieldUtil::ClearFieldModificationWatch(jvmtiEnv* jenv, jclass klass, jfieldID field) {
   ArtJvmTiEnv* env = ArtJvmTiEnv::AsArtJvmTiEnv(jenv);
   art::WriterMutexLock lk(art::Thread::Current(), env->event_info_mutex_);
   if (klass == nullptr) {
     return ERR(INVALID_CLASS);
   }
   if (field == nullptr) {
     return ERR(INVALID_FIELDID);
   }
   auto pos = env->modify_watched_fields.find(art::jni::DecodeArtField(field));
   if (pos == env->modify_watched_fields.end()) {
     return ERR(NOT_FOUND);
   }
   env->modify_watched_fields.erase(pos);
   return OK;
 }

 jvmtiError FieldUtil::SetFieldAccessWatch(jvmtiEnv* jenv, jclass klass, jfieldID field) {
   ArtJvmTiEnv* env = ArtJvmTiEnv::AsArtJvmTiEnv(jenv);
   art::WriterMutexLock lk(art::Thread::Current(), env->event_info_mutex_);
   if (klass == nullptr) {
     return ERR(INVALID_CLASS);
   }
   if (field == nullptr) {
     return ERR(INVALID_FIELDID);
   }
   auto res_pair = env->access_watched_fields.insert(art::jni::DecodeArtField(field));
   if (!res_pair.second) {
     // Didn't get inserted because it's already present!
     return ERR(DUPLICATE);
   }
   return OK;
 }

 jvmtiError FieldUtil::ClearFieldAccessWatch(jvmtiEnv* jenv, jclass klass, jfieldID field) {
   ArtJvmTiEnv* env = ArtJvmTiEnv::AsArtJvmTiEnv(jenv);
   art::WriterMutexLock lk(art::Thread::Current(), env->event_info_mutex_);
   if (klass == nullptr) {
     return ERR(INVALID_CLASS);
   }
   if (field == nullptr) {
     return ERR(INVALID_FIELDID);
   }
   auto pos = env->access_watched_fields.find(art::jni::DecodeArtField(field));
   if (pos == env->access_watched_fields.end()) {
     return ERR(NOT_FOUND);
   }
   env->access_watched_fields.erase(pos);
   return OK;
 }

 }  // namespace openjdkjvmti
	/* Copyright (C) 2016 The Android Open Source Project
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This file implements interfaces from the file jvmti.h. This implementation
	* is licensed under the same terms as the file jvmti.h. The
	* copyright and license information for the file jvmti.h follows.
	*
	* Copyright (c) 2003, 2011, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle in the LICENSE file that accompanied this code.
	*
	* This code is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/

	#include "ti_field.h"
	#include <unordered_map>

	#include "android-base/thread_annotations.h"
	#include "art_field-inl.h"
	#include "art_field.h"
	#include "art_jvmti.h"
	#include "base/enums.h"
	#include "base/locks.h"
	#include "dex/dex_file_annotations.h"
	#include "dex/modifiers.h"
	#include "jni/jni_internal.h"
	#include "mirror/object_array-inl.h"
	#include "reflective_value_visitor.h"
	#include "runtime.h"
	#include "runtime_callbacks.h"
	#include "scoped_thread_state_change-inl.h"
	#include "thread-current-inl.h"

	namespace openjdkjvmti {

	class JvmtiFieldReflectionSource : public art::ReflectionSourceInfo {
	public:
	JvmtiFieldReflectionSource(bool is_access, art::ArtField* f)
	: art::ReflectionSourceInfo(art::ReflectionSourceType::kSourceMiscInternal),
	is_access_(is_access),
	f_(f) {}
	void Describe(std::ostream& os) const override REQUIRES_SHARED(art::Locks::mutator_lock_) {
	art::ReflectionSourceInfo::Describe(os);
	os << " jvmti Field" << (is_access_ ? "Access" : "Modification")
	<< "Watch Target=" << f_->PrettyField();
	}

	private:
	bool is_access_;
	art::ArtField* f_;
	};
	struct FieldReflectiveValueCallback : public art::ReflectiveValueVisitCallback {
	public:
	void VisitReflectiveTargets(art::ReflectiveValueVisitor* visitor)
	REQUIRES(art::Locks::mutator_lock_) {
	art::Thread* self = art::Thread::Current();
	event_handler->ForEachEnv(self, [&](ArtJvmTiEnv* env) NO_THREAD_SAFETY_ANALYSIS {
	art::Locks::mutator_lock_->AssertExclusiveHeld(self);
	art::WriterMutexLock mu(self, env->event_info_mutex_);
	std::vector<std::pair<art::ArtField, art::ArtField>> updated_access_fields;
	for (auto it : env->access_watched_fields) {
	art::ArtField* af =
	visitor->VisitField(it, JvmtiFieldReflectionSource(/is_access=/true, it));
	if (af != it) {
	updated_access_fields.push_back({ af, it });
	}
	}
	for (auto it : updated_access_fields) {
	DCHECK(env->access_watched_fields.find(it.second) != env->access_watched_fields.end());
	env->access_watched_fields.erase(it.second);
	env->access_watched_fields.insert(it.first);
	}
	std::vector<std::pair<art::ArtField, art::ArtField>> updated_modify_fields;
	for (auto it : env->modify_watched_fields) {
	art::ArtField* af =
	visitor->VisitField(it, JvmtiFieldReflectionSource(/is_access=/false, it));
	if (af != it) {
	updated_modify_fields.push_back({ af, it });
	}
	}
	for (auto it : updated_modify_fields) {
	DCHECK(env->modify_watched_fields.find(it.second) != env->modify_watched_fields.end());
	env->modify_watched_fields.erase(it.second);
	env->modify_watched_fields.insert(it.first);
	}
	});
	}

	EventHandler* event_handler = nullptr;
	};

	static FieldReflectiveValueCallback gReflectiveValueCallback;

	void FieldUtil::Register(EventHandler* eh) {
	gReflectiveValueCallback.event_handler = eh;
	art::ScopedThreadStateChange stsc(art::Thread::Current(),
	art::ThreadState::kWaitingForDebuggerToAttach);
	art::ScopedSuspendAll ssa("Add reflective value visit callback");
	art::RuntimeCallbacks* callbacks = art::Runtime::Current()->GetRuntimeCallbacks();
	callbacks->AddReflectiveValueVisitCallback(&gReflectiveValueCallback);
	}

	void FieldUtil::Unregister() {
	art::ScopedThreadStateChange stsc(art::Thread::Current(),
	art::ThreadState::kWaitingForDebuggerToAttach);
	art::ScopedSuspendAll ssa("Remove reflective value visit callback");
	art::RuntimeCallbacks* callbacks = art::Runtime::Current()->GetRuntimeCallbacks();
	callbacks->RemoveReflectiveValueVisitCallback(&gReflectiveValueCallback);
	}
	// Note: For all these functions, we could do a check that the field actually belongs to the given
	// class. But the spec seems to assume a certain encoding of the field ID, and so doesn't
	// specify any errors.

	jvmtiError FieldUtil::GetFieldName(jvmtiEnv* env,
	jclass klass,
	jfieldID field,
	char** name_ptr,
	char** signature_ptr,
	char** generic_ptr) {
	if (klass == nullptr) {
	return ERR(INVALID_CLASS);
	}
	if (field == nullptr) {
	return ERR(INVALID_FIELDID);
	}

	art::ScopedObjectAccess soa(art::Thread::Current());
	art::ArtField* art_field = art::jni::DecodeArtField(field);

	JvmtiUniquePtr<char[]> name_copy;
	if (name_ptr != nullptr) {
	const char* field_name = art_field->GetName();
	if (field_name == nullptr) {
	field_name = "<error>";
	}
	jvmtiError ret;
	name_copy = CopyString(env, field_name, &ret);
	if (name_copy == nullptr) {
	return ret;
	}
	*name_ptr = name_copy.get();
	}

	JvmtiUniquePtr<char[]> signature_copy;
	if (signature_ptr != nullptr) {
	const char* sig = art_field->GetTypeDescriptor();
	jvmtiError ret;
	signature_copy = CopyString(env, sig, &ret);
	if (signature_copy == nullptr) {
	return ret;
	}
	*signature_ptr = signature_copy.get();
	}

	if (generic_ptr != nullptr) {
	*generic_ptr = nullptr;
	if (!art_field->GetDeclaringClass()->IsProxyClass()) {
	art::ObjPtr<art::mirror::ObjectArray<art::mirror::String>> str_array =
	art::annotations::GetSignatureAnnotationForField(art_field);
	if (str_array != nullptr) {
	std::ostringstream oss;
	for (auto str : str_array->Iterate()) {
	oss << str->ToModifiedUtf8();
	}
	std::string output_string = oss.str();
	jvmtiError ret;
	JvmtiUniquePtr<char[]> copy = CopyString(env, output_string.c_str(), &ret);
	if (copy == nullptr) {
	return ret;
	}
	*generic_ptr = copy.release();
	} else if (soa.Self()->IsExceptionPending()) {
	// TODO: Should we report an error here?
	soa.Self()->ClearException();
	}
	}
	}

	// Everything is fine, release the buffers.
	name_copy.release();
	signature_copy.release();

	return ERR(NONE);
	}

	jvmtiError FieldUtil::GetFieldDeclaringClass([[maybe_unused]] jvmtiEnv* env,
	jclass klass,
	jfieldID field,
	jclass* declaring_class_ptr) {
	if (klass == nullptr) {
	return ERR(INVALID_CLASS);
	}
	if (field == nullptr) {
	return ERR(INVALID_FIELDID);
	}
	if (declaring_class_ptr == nullptr) {
	return ERR(NULL_POINTER);
	}

	art::ScopedObjectAccess soa(art::Thread::Current());
	art::ArtField* art_field = art::jni::DecodeArtField(field);
	art::ObjPtr<art::mirror::Class> field_klass = art_field->GetDeclaringClass();

	*declaring_class_ptr = soa.AddLocalReference<jclass>(field_klass);

	return ERR(NONE);
	}

	jvmtiError FieldUtil::GetFieldModifiers([[maybe_unused]] jvmtiEnv* env,
	jclass klass,
	jfieldID field,
	jint* modifiers_ptr) {
	if (klass == nullptr) {
	return ERR(INVALID_CLASS);
	}
	if (field == nullptr) {
	return ERR(INVALID_FIELDID);
	}
	if (modifiers_ptr == nullptr) {
	return ERR(NULL_POINTER);
	}

	art::ScopedObjectAccess soa(art::Thread::Current());
	art::ArtField* art_field = art::jni::DecodeArtField(field);
	// Note: Keep this code in sync with Field.getModifiers.
	uint32_t modifiers = art_field->GetAccessFlags() & 0xFFFF;

	*modifiers_ptr = modifiers;
	return ERR(NONE);
	}

	jvmtiError FieldUtil::IsFieldSynthetic([[maybe_unused]] jvmtiEnv* env,
	jclass klass,
	jfieldID field,
	jboolean* is_synthetic_ptr) {
	if (klass == nullptr) {
	return ERR(INVALID_CLASS);
	}
	if (field == nullptr) {
	return ERR(INVALID_FIELDID);
	}
	if (is_synthetic_ptr == nullptr) {
	return ERR(NULL_POINTER);
	}

	art::ScopedObjectAccess soa(art::Thread::Current());
	art::ArtField* art_field = art::jni::DecodeArtField(field);
	uint32_t modifiers = art_field->GetAccessFlags();

	*is_synthetic_ptr = ((modifiers & art::kAccSynthetic) != 0) ? JNI_TRUE : JNI_FALSE;
	return ERR(NONE);
	}

	jvmtiError FieldUtil::SetFieldModificationWatch(jvmtiEnv* jenv, jclass klass, jfieldID field) {
	ArtJvmTiEnv* env = ArtJvmTiEnv::AsArtJvmTiEnv(jenv);
	art::WriterMutexLock lk(art::Thread::Current(), env->event_info_mutex_);
	if (klass == nullptr) {
	return ERR(INVALID_CLASS);
	}
	if (field == nullptr) {
	return ERR(INVALID_FIELDID);
	}
	auto res_pair = env->modify_watched_fields.insert(art::jni::DecodeArtField(field));
	if (!res_pair.second) {
	// Didn't get inserted because it's already present!
	return ERR(DUPLICATE);
	}
	return OK;
	}

	jvmtiError FieldUtil::ClearFieldModificationWatch(jvmtiEnv* jenv, jclass klass, jfieldID field) {
	ArtJvmTiEnv* env = ArtJvmTiEnv::AsArtJvmTiEnv(jenv);
	art::WriterMutexLock lk(art::Thread::Current(), env->event_info_mutex_);
	if (klass == nullptr) {
	return ERR(INVALID_CLASS);
	}
	if (field == nullptr) {
	return ERR(INVALID_FIELDID);
	}
	auto pos = env->modify_watched_fields.find(art::jni::DecodeArtField(field));
	if (pos == env->modify_watched_fields.end()) {
	return ERR(NOT_FOUND);
	}
	env->modify_watched_fields.erase(pos);
	return OK;
	}

	jvmtiError FieldUtil::SetFieldAccessWatch(jvmtiEnv* jenv, jclass klass, jfieldID field) {
	ArtJvmTiEnv* env = ArtJvmTiEnv::AsArtJvmTiEnv(jenv);
	art::WriterMutexLock lk(art::Thread::Current(), env->event_info_mutex_);
	if (klass == nullptr) {
	return ERR(INVALID_CLASS);
	}
	if (field == nullptr) {
	return ERR(INVALID_FIELDID);
	}
	auto res_pair = env->access_watched_fields.insert(art::jni::DecodeArtField(field));
	if (!res_pair.second) {
	// Didn't get inserted because it's already present!
	return ERR(DUPLICATE);
	}
	return OK;
	}

	jvmtiError FieldUtil::ClearFieldAccessWatch(jvmtiEnv* jenv, jclass klass, jfieldID field) {
	ArtJvmTiEnv* env = ArtJvmTiEnv::AsArtJvmTiEnv(jenv);
	art::WriterMutexLock lk(art::Thread::Current(), env->event_info_mutex_);
	if (klass == nullptr) {
	return ERR(INVALID_CLASS);
	}
	if (field == nullptr) {
	return ERR(INVALID_FIELDID);
	}
	auto pos = env->access_watched_fields.find(art::jni::DecodeArtField(field));
	if (pos == env->access_watched_fields.end()) {
	return ERR(NOT_FOUND);
	}
	env->access_watched_fields.erase(pos);
	return OK;
	}

	} // namespace openjdkjvmti