FastJNI_java_lang_ref_Reference.cpp

/*******************************************************************************
 * Copyright IBM Corp. and others 2001
 *
 * This program and the accompanying materials are made available under
 * the terms of the Eclipse Public License 2.0 which accompanies this
 * distribution and is available at https://www.eclipse.org/legal/epl-2.0/
 * or the Apache License, Version 2.0 which accompanies this distribution and
 * is available at https://www.apache.org/licenses/LICENSE-2.0.
 *
 * This Source Code may also be made available under the following
 * Secondary Licenses when the conditions for such availability set
 * forth in the Eclipse Public License, v. 2.0 are satisfied: GNU
 * General Public License, version 2 with the GNU Classpath
 * Exception [1] and GNU General Public License, version 2 with the
 * OpenJDK Assembly Exception [2].
 *
 * [1] https://www.gnu.org/software/classpath/license.html
 * [2] https://openjdk.org/legal/assembly-exception.html
 *
 * SPDX-License-Identifier: EPL-2.0 OR Apache-2.0 OR GPL-2.0-only WITH Classpath-exception-2.0 OR GPL-2.0-only WITH OpenJDK-assembly-exception-1.0
 *******************************************************************************/

#include "fastJNI.h"
#include "j9protos.h"
#include "j9consts.h"
#include "omrgcconsts.h"
#include "omr.h"

extern "C" {

/* java.lang.ref.Reference: private native T getImpl() */
j9object_t JNICALL
Fast_java_lang_ref_Reference_getImpl(J9VMThread *currentThread, j9object_t receiverObject)
{
	return currentThread->javaVM->memoryManagerFunctions->j9gc_objaccess_referenceGet(currentThread, receiverObject);
}

/* java.lang.ref.Reference: private native void reprocess() */
void JNICALL
Fast_java_lang_ref_Reference_reprocess(J9VMThread *currentThread, j9object_t receiverObject)
{
	J9JavaVM* javaVM = currentThread->javaVM;
	J9MemoryManagerFunctions* mmFuncs = javaVM->memoryManagerFunctions;
	/* Under the SATB barrier call getReferent (for metronome or standard SATB CM), this will mark the referent if a cycle is in progress.
	 * Or reprocess this object if a concurrent GC (incremental cards) is in progress */
	mmFuncs->j9gc_objaccess_referenceReprocess(currentThread, receiverObject);
}

#if JAVA_SPEC_VERSION >= 16
/* java.lang.ref.Reference: public native boolean refersTo(T target) */
jboolean JNICALL
Fast_java_lang_ref_Reference_refersTo(J9VMThread *currentThread, j9object_t reference, j9object_t target)
{
	J9JavaVM * const vm = currentThread->javaVM;
	jboolean result = JNI_FALSE;

	if (NULL == reference) {
		vm->internalVMFunctions->setCurrentException(currentThread, J9VMCONSTANTPOOL_JAVALANGNULLPOINTEREXCEPTION, NULL);
	} else {
		j9object_t referent = J9VMJAVALANGREFREFERENCE_REFERENT_VM(vm, reference);

		if (referent == target) {
			result = JNI_TRUE;
		}
	}

	return result;
}
#endif /* JAVA_SPEC_VERSION >= 16 */

J9_FAST_JNI_METHOD_TABLE(java_lang_ref_Reference)
	J9_FAST_JNI_METHOD("getImpl", "()Ljava/lang/Object;", Fast_java_lang_ref_Reference_getImpl,
		J9_FAST_JNI_RETAIN_VM_ACCESS | J9_FAST_JNI_NOT_GC_POINT | J9_FAST_JNI_NO_NATIVE_METHOD_FRAME | J9_FAST_JNI_NO_EXCEPTION_THROW |
		J9_FAST_JNI_NO_SPECIAL_TEAR_DOWN | J9_FAST_JNI_DO_NOT_WRAP_OBJECTS)
	J9_FAST_JNI_METHOD("reprocess", "()V", Fast_java_lang_ref_Reference_reprocess,
		J9_FAST_JNI_RETAIN_VM_ACCESS | J9_FAST_JNI_NOT_GC_POINT | J9_FAST_JNI_NO_NATIVE_METHOD_FRAME | J9_FAST_JNI_NO_EXCEPTION_THROW |
		J9_FAST_JNI_NO_SPECIAL_TEAR_DOWN | J9_FAST_JNI_DO_NOT_WRAP_OBJECTS)
#if JAVA_SPEC_VERSION >= 16
	J9_FAST_JNI_METHOD("refersTo", "(Ljava/lang/Object;)Z", Fast_java_lang_ref_Reference_refersTo,
		J9_FAST_JNI_RETAIN_VM_ACCESS | J9_FAST_JNI_DO_NOT_WRAP_OBJECTS)
#endif /* JAVA_SPEC_VERSION >= 16 */
J9_FAST_JNI_METHOD_TABLE_END
}