ScavengerThreadRescanner.hpp

/*******************************************************************************
 * Copyright IBM Corp. and others 1991
 *
 * 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
 *******************************************************************************/

#ifndef SCAVENGERTHREADRESCANNER_HPP_
#define SCAVENGERTHREADRESCANNER_HPP_

#include "j9cfg.h"
#include "ModronAssertions.h"

#if defined(OMR_GC_MODRON_SCAVENGER)
#include "EnvironmentStandard.hpp"
#include "RootScanner.hpp"
#include "Scavenger.hpp"

/**
 * A specialized root scanner for rescanning thread slots in order to auto-remember stack- (or thread-)
 * referenced object
 */
class MM_ScavengerThreadRescanner : public MM_RootScanner
{
private:
	MM_Scavenger *_scavenger;

public:
	MM_ScavengerThreadRescanner(MM_EnvironmentBase *env, MM_Scavenger *scavenger) :
	MM_RootScanner(env),
	_scavenger(scavenger)
	{
		_typeId = __FUNCTION__;
		setNurseryReferencesOnly(true);
	};

	virtual void doStackSlot(omrobjectptr_t *slotPtr, void *walkState, const void* stackLocation) {
		_scavenger->rescanThreadSlot(MM_EnvironmentStandard::getEnvironment(_env), slotPtr);
	}

#if JAVA_SPEC_VERSION >= 24
	virtual void doContinuationSlot(J9Object **slotPtr, GC_ContinuationSlotIterator *continuationSlotIterator) {
		_scavenger->rescanThreadSlot(MM_EnvironmentStandard::getEnvironment(_env), slotPtr);
	}
#endif /* JAVA_SPEC_VERSION >= 24 */

	virtual void doVMThreadSlot(omrobjectptr_t *slotPtr, GC_VMThreadIterator *vmThreadIterator) {
		_scavenger->rescanThreadSlot(MM_EnvironmentStandard::getEnvironment(_env), slotPtr);
	}

	virtual void doSlot(omrobjectptr_t *slotPtr) {
		/* we only process thread and stack slots with this scanner */
		Assert_MM_unreachable();
	}

	virtual void doClass(J9Class *clazz) {
		/* we do not process classes in the scavenger */
		Assert_MM_unreachable();
	}

#if defined(J9VM_GC_FINALIZATION)
	virtual void doFinalizableObject(omrobjectptr_t object) {
		Assert_MM_unreachable();
	}
#endif /* J9VM_GC_FINALIZATION */
};
#endif /* defined(OMR_GC_MODRON_SCAVENGER) */

#endif /* SCAVENGERTHREADRESCANNER_HPP_ */