/*
* This file is part of the Jikes RVM project (http://jikesrvm.org).
*
* This file is licensed to You under the Common Public License (CPL);
* You may not use this file except in compliance with the License. You
* may obtain a copy of the License at
*
* http://www.opensource.org/licenses/cpl1.0.php
*
* See the COPYRIGHT.txt file distributed with this work for information
* regarding copyright ownership.
*/
package org.mmtk.plan.semispace;
import org.mmtk.plan.*;
import org.mmtk.policy.CopyLocal;
import org.mmtk.policy.Space;
import org.mmtk.utility.alloc.Allocator;
import org.vmmagic.unboxed.*;
import org.vmmagic.pragma.*;
/**
* This class implements <i>per-mutator thread</i> behavior
* and state for the <i>SS</i> plan, which implements a full-heap
* semi-space collector.<p>
*
* Specifically, this class defines <i>SS</i> mutator-time allocation
* and per-mutator thread collection semantics (flushing and restoring
* per-mutator allocator state).<p>
*
* See {@link SS} for an overview of the semi-space algorithm.<p>
*
* @see SS
* @see SSCollector
* @see StopTheWorldMutator
* @see MutatorContext
*/
@Uninterruptible public abstract class SSMutator extends StopTheWorldMutator {
/****************************************************************************
* Instance fields
*/
protected final CopyLocal ss;
/****************************************************************************
*
* Initialization
*/
/**
* Constructor
*/
public SSMutator() {
ss = new CopyLocal(SS.copySpace0);
}
/****************************************************************************
*
* Mutator-time allocation
*/
/**
* Allocate space (for an object)
*
* @param bytes The size of the space to be allocated (in bytes)
* @param align The requested alignment.
* @param offset The alignment offset.
* @param allocator The allocator number to be used for this allocation
* @param site Allocation site
* @return The address of the first byte of the allocated region
*/
@Inline
public Address alloc(int bytes, int align, int offset, int allocator, int site) {
if (allocator == SS.ALLOC_SS)
return ss.alloc(bytes, align, offset);
else
return super.alloc(bytes, align, offset, allocator, site);
}
/**
* Perform post-allocation actions. For many allocators none are
* required.
*
* @param object The newly allocated object
* @param typeRef The type reference for the instance being created
* @param bytes The size of the space to be allocated (in bytes)
* @param allocator The allocator number to be used for this allocation
*/
@Inline
public void postAlloc(ObjectReference object, ObjectReference typeRef,
int bytes, int allocator) {
if (allocator == SS.ALLOC_SS) return;
super.postAlloc(object, typeRef, bytes, allocator);
}
/**
* Return the space into which an allocator is allocating. This
* particular method will match against those spaces defined at this
* level of the class hierarchy. Subclasses must deal with spaces
* they define and refer to superclasses appropriately. This exists
* to support {@link MutatorContext#getOwnAllocator(Allocator)}.
*
* @see MutatorContext#getOwnAllocator(Allocator)
* @param a An allocator
* @return The space into which <code>a</code> is allocating, or
* <code>null</code> if there is no space associated with
* <code>a</code>.
*/
public Space getSpaceFromAllocator(Allocator a) {
if (a == ss) return SS.toSpace();
return super.getSpaceFromAllocator(a);
}
/**
* Return the allocator instance associated with a space
* <code>space</code>, for this plan instance. This exists
* to support {@link MutatorContext#getOwnAllocator(Allocator)}.
*
* @see MutatorContext#getOwnAllocator(Allocator)
* @param space The space for which the allocator instance is desired.
* @return The allocator instance associated with this plan instance
* which is allocating into <code>space</code>, or <code>null</code>
* if no appropriate allocator can be established.
*/
public Allocator getAllocatorFromSpace(Space space) {
if (space == SS.copySpace0 || space == SS.copySpace1) return ss;
return super.getAllocatorFromSpace(space);
}
/****************************************************************************
*
* Collection
*/
/**
* Perform a per-mutator collection phase.
*
* @param phaseId The collection phase to perform
* @param primary Perform any single-threaded activities using this thread.
*/
@Inline
public void collectionPhase(short phaseId, boolean primary) {
if (phaseId == SS.PREPARE) {
super.collectionPhase(phaseId, primary);
return;
}
if (phaseId == SS.RELEASE) {
super.collectionPhase(phaseId, primary);
// rebind the allocation bump pointer to the appropriate semispace.
ss.rebind(SS.toSpace());
return;
}
super.collectionPhase(phaseId, primary);
}
/****************************************************************************
*
* Miscellaneous
*/
/**
* Show the status of each of the allocators.
*/
public final void show() {
ss.show();
los.show();
immortal.show();
}
}