/*
* This file is part of the Jikes RVM project (http://jikesrvm.org).
*
* This file is licensed to You under the Eclipse Public License (EPL);
* 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/eclipse-1.0.php
*
* See the COPYRIGHT.txt file distributed with this work for information
* regarding copyright ownership.
*/
package org.mmtk.plan;
import org.mmtk.policy.MarkSweepLocal;
import org.mmtk.policy.Space;
import org.mmtk.policy.ImmortalLocal;
import org.mmtk.policy.LargeObjectLocal;
import org.mmtk.utility.alloc.Allocator;
import org.mmtk.utility.alloc.BumpPointer;
import org.mmtk.utility.Constants;
import org.mmtk.utility.Log;
import org.mmtk.vm.VM;
import org.vmmagic.pragma.*;
import org.vmmagic.unboxed.*;
/**
* This class (and its sub-classes) implement <i>per-mutator thread</i>
* behavior. We assume <i>N</i> collector threads and <i>M</i>
* mutator threads, where <i>N</i> is often equal to the number of
* available processors, P (for P-way parallelism at GC-time), and
* <i>M</i> may simply be the number of mutator (application) threads.
* Both <i>N</i> and <i>M</i> are determined by the VM, not MMTk. In
* the case where a VM uses posix threads (pthreads) for each mutator
* ("1:1" threading), <i>M</i> will typically be equal to the number of
* mutator threads. When a uses "green threads" or a hybrid threading
* scheme (such as Jikes RVM), <i>M</i> will typically be equal to the
* level of <i>true</i> parallelism (ie the number of underlying
* kernel threads).<p>
*
* MMTk assumes that the VM instantiates instances of MutatorContext
* in thread local storage (TLS) for each thread participating in
* collection. Accesses to this state are therefore assumed to be
* low-cost during mutator time.<p>
*
* This class (and its children) is therefore used for unsynchronized
* per-mutator operations such as <i>allocation</i> and <i>write barriers</i>.
* The semantics and necessary state for these operations are therefore
* specified in the GC-specific subclasses of this class.
*
* MMTk explicitly separates thread-local (this class) and global
* operations (@see Plan), so that syncrhonization is localized
* and explicit, and thus hopefully minimized (@see Plan). Gloabl (Plan)
* and per-thread (this class) state are also explicitly separated.
* Operations in this class (and its children) are therefore strictly
* local to each mutator thread, and synchronized operations always
* happen via access to explicitly global classes such as Plan and its
* children. Therefore only <i>"fast path"</i> (unsynchronized)
* allocation and barrier semantics are defined in MutatorContext and
* its subclasses. These call out to <i>"slow path"</i> (synchronize(d)
* methods which have global state and are globally synchronized. For
* example, an allocation fast path may bump a pointer without any
* syncrhonization (the "fast path") until a limit is reached, at which
* point the "slow path" is called, and more memory is aquired from a
* global resource.<p>
*
* As the super-class of all per-mutator contexts, this class implements
* basic per-mutator behavior common to all MMTk collectors, including
* support for immortal and large object space allocation, as well as
* empty stubs for write barriers (to be overridden by sub-classes as
* needed).
*
* @see CollectorContext
* @see org.mmtk.vm.ActivePlan
* @see Plan
*/
@Uninterruptible
public abstract class MutatorContext implements Constants {
/****************************************************************************
* Initialization
*/
/**
* Notify that the mutator context is registered and ready to execute. From
* this point it will be included in iterations over mutators.
*
* @param id The id of this mutator context.
*/
public void initMutator(int id) {
this.id = id;
}
/**
* The mutator is about to be cleaned up, make sure all local data is returned.
*/
public void deinitMutator() {
flush();
}
/****************************************************************************
* Instance fields
*/
/** Unique mutator identifier */
private int id;
/** Used for printing log information in a thread safe manner */
protected final Log log = new Log();
/** Per-mutator allocator into the immortal space */
protected final BumpPointer immortal = new ImmortalLocal(Plan.immortalSpace);
/** Per-mutator allocator into the large object space */
protected final LargeObjectLocal los = new LargeObjectLocal(Plan.loSpace);
/** Per-mutator allocator into the small code space */
protected final MarkSweepLocal smcode = Plan.USE_CODE_SPACE ? new MarkSweepLocal(Plan.smallCodeSpace) : null;
/** Per-mutator allocator into the large code space */
protected final LargeObjectLocal lgcode = Plan.USE_CODE_SPACE ? new LargeObjectLocal(Plan.largeCodeSpace) : null;
/** Per-mutator allocator into the non moving space */
protected final MarkSweepLocal nonmove = new MarkSweepLocal(Plan.nonMovingSpace);
/****************************************************************************
*
* Collection.
*/
/**
* Perform a per-mutator collection phase.
*
* @param phaseId The unique phase identifier
* @param primary Should this thread be used to execute any single-threaded
* local operations?
*/
public abstract void collectionPhase(short phaseId, boolean primary);
/****************************************************************************
*
* Allocation.
*/
/**
* Run-time check of the allocator to use for a given allocation
*
* At the moment this method assumes that allocators will use the simple
* (worst) method of aligning to determine if the object is a large object
* to ensure that no objects are larger than other allocators can handle.
*
* @param bytes The number of bytes to be allocated
* @param align The requested alignment.
* @param allocator The allocator statically assigned to this allocation
* @return The allocator dynamically assigned to this allocation
*/
@Inline
public int checkAllocator(int bytes, int align, int allocator) {
int maxBytes = Allocator.getMaximumAlignedSize(bytes, align);
if (allocator == Plan.ALLOC_DEFAULT) {
return (maxBytes > Plan.MAX_NON_LOS_DEFAULT_ALLOC_BYTES) ? Plan.ALLOC_LOS : allocator;
}
if (Plan.USE_CODE_SPACE && allocator == Plan.ALLOC_CODE) {
return (maxBytes > Plan.MAX_NON_LOS_NONMOVING_ALLOC_BYTES) ? Plan.ALLOC_LARGE_CODE : allocator;
}
if (allocator == Plan.ALLOC_NON_REFERENCE) {
return (maxBytes > Plan.MAX_NON_LOS_DEFAULT_ALLOC_BYTES) ? Plan.ALLOC_LOS : Plan.ALLOC_DEFAULT;
}
if (allocator == Plan.ALLOC_NON_MOVING) {
return (maxBytes > Plan.MAX_NON_LOS_NONMOVING_ALLOC_BYTES) ? Plan.ALLOC_LOS : allocator;
}
return allocator;
}
/**
* Allocate memory for an object.
*
* @param bytes The number of bytes required for the object.
* @param align Required alignment for the object.
* @param offset Offset associated with the alignment.
* @param allocator The allocator associated with this request.
* @param site Allocation site
* @return The low address of the allocated chunk.
*/
@Inline
public Address alloc(int bytes, int align, int offset, int allocator, int site) {
switch (allocator) {
case Plan.ALLOC_LOS: return los.alloc(bytes, align, offset);
case Plan.ALLOC_IMMORTAL: return immortal.alloc(bytes, align, offset);
case Plan.ALLOC_CODE: return smcode.alloc(bytes, align, offset);
case Plan.ALLOC_LARGE_CODE: return lgcode.alloc(bytes, align, offset);
case Plan.ALLOC_NON_MOVING: return nonmove.alloc(bytes, align, offset);
default:
VM.assertions.fail("No such allocator");
return Address.zero();
}
}
/**
* Perform post-allocation actions. For many allocators none are
* required.
*
* @param ref 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 ref, ObjectReference typeRef,
int bytes, int allocator) {
switch (allocator) {
case Plan.ALLOC_LOS: Plan.loSpace.initializeHeader(ref, true); return;
case Plan.ALLOC_IMMORTAL: Plan.immortalSpace.initializeHeader(ref); return;
case Plan.ALLOC_CODE: Plan.smallCodeSpace.initializeHeader(ref, true); return;
case Plan.ALLOC_LARGE_CODE: Plan.largeCodeSpace.initializeHeader(ref, true); return;
case Plan.ALLOC_NON_MOVING: Plan.nonMovingSpace.initializeHeader(ref, true); return;
default:
VM.assertions.fail("No such allocator");
}
}
/****************************************************************************
*
* Space - Allocator mapping.
*/
/**
* Return the allocator instance associated with a space
* <code>space</code>, for this plan instance.
*
* @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 == Plan.immortalSpace) return immortal;
if (space == Plan.loSpace) return los;
if (space == Plan.nonMovingSpace) return nonmove;
if (Plan.USE_CODE_SPACE && space == Plan.smallCodeSpace) return smcode;
if (Plan.USE_CODE_SPACE && space == Plan.largeCodeSpace) return lgcode;
// Invalid request has been made
if (space == Plan.metaDataSpace) {
VM.assertions.fail("MutatorContext.getAllocatorFromSpace given meta space");
} else if (space != null) {
VM.assertions.fail("MutatorContext.getAllocatorFromSpace given invalid space");
} else {
VM.assertions.fail("MutatorContext.getAllocatorFromSpace given null space");
}
return null;
}
/****************************************************************************
*
* Write and read barriers. By default do nothing, override if
* appropriate.
*/
/**
* Called by ReferenceProcessor when a java.lang.reference is updated,
* so the GPU reference graph can be updated too.
*
* @param ref The reference
* @param referent The referent being written
* @param offset The offset to the referent field
*/
@Inline
public void javaLangReferenceUpdated(ObjectReference ref, ObjectReference referent) {
// Either: read barriers are used and this is overridden, or
// read barriers are not used and this is never called
if (VM.VERIFY_ASSERTIONS) VM.assertions._assert(false);
}
/**
* Read a reference type. In a concurrent collector this may
* involve adding the referent to the marking queue.
*
* @param referent The referent being read.
* @return The new referent.
*/
@Inline
public ObjectReference javaLangReferenceReadBarrier(ObjectReference referent) {
// Either: read barriers are used and this is overridden, or
// read barriers are not used and this is never called
if (VM.VERIFY_ASSERTIONS) VM.assertions._assert(false);
return ObjectReference.nullReference();
}
/**
* Write a boolean. Take appropriate write barrier actions.<p>
*
* <b>By default do nothing, override if appropriate.</b>
*
* @param src The object into which the new reference will be stored
* @param slot The address into which the new reference will be
* stored.
* @param value The value of the new boolean
* @param metaDataA A value that assists the host VM in creating a store
* @param metaDataB A value that assists the host VM in creating a store
* @param mode The context in which the store occurred
*/
public void booleanWrite(ObjectReference src, Address slot, boolean value, Word metaDataA, Word metaDataB, int mode) {
// Either: write barriers are used and this is overridden, or
// write barriers are not used and this is never called
if (VM.VERIFY_ASSERTIONS) VM.assertions._assert(false);
}
/**
* Read a boolean. Take appropriate read barrier action, and
* return the value that was read.<p> This is a <b>substituting<b>
* barrier. The call to this barrier takes the place of a load.<p>
*
* @param src The object reference holding the field being read.
* @param slot The address of the slot being read.
* @param metaDataA A value that assists the host VM in creating a load
* @param metaDataB A value that assists the host VM in creating a load
* @param mode The context in which the load occurred
* @return The boolean that was read.
*/
@Inline
public boolean booleanRead(ObjectReference src, Address slot, Word metaDataA, Word metaDataB, int mode) {
// Either: read barriers are used and this is overridden, or
// read barriers are not used and this is never called
if (VM.VERIFY_ASSERTIONS) VM.assertions._assert(false);
return false;
}
/**
* A number of booleans are about to be copied from object
* <code>src</code> to object <code>dst</code> (as in an array
* copy). Thus, <code>dst</code> is the mutated object. Take
* appropriate write barrier actions.<p>
*
* @param src The source array
* @param srcOffset The starting source offset
* @param dst The destination array
* @param dstOffset The starting destination offset
* @param bytes The number of bytes to be copied
* @return True if the update was performed by the barrier, false if
* left to the caller (always false in this case).
*/
public boolean booleanBulkCopy(ObjectReference src, Offset srcOffset, ObjectReference dst, Offset dstOffset, int bytes) {
// Either: bulk copy is supported and this is overridden, or
// write barriers are not used and this is never called
if (VM.VERIFY_ASSERTIONS) VM.assertions._assert(false);
return false;
}
/**
* Write a byte. Take appropriate write barrier actions.<p>
*
* <b>By default do nothing, override if appropriate.</b>
*
* @param src The object into which the new reference will be stored
* @param slot The address into which the new reference will be
* stored.
* @param value The value of the new byte
* @param metaDataA A value that assists the host VM in creating a store
* @param metaDataB A value that assists the host VM in creating a store
* @param mode The context in which the store occurred
*/
public void byteWrite(ObjectReference src, Address slot, byte value, Word metaDataA, Word metaDataB, int mode) {
// Either: write barriers are used and this is overridden, or
// write barriers are not used and this is never called
if (VM.VERIFY_ASSERTIONS) VM.assertions._assert(false);
}
/**
* Read a byte. Take appropriate read barrier action, and
* return the value that was read.<p> This is a <b>substituting<b>
* barrier. The call to this barrier takes the place of a load.<p>
*
* @param src The object reference holding the field being read.
* @param slot The address of the slot being read.
* @param metaDataA A value that assists the host VM in creating a load
* @param metaDataB A value that assists the host VM in creating a load
* @param mode The context in which the load occurred
* @return The byte that was read.
*/
@Inline
public byte byteRead(ObjectReference src, Address slot, Word metaDataA, Word metaDataB, int mode) {
// Either: read barriers are used and this is overridden, or
// read barriers are not used and this is never called
if (VM.VERIFY_ASSERTIONS) VM.assertions._assert(false);
return 0;
}
/**
* A number of bytes are about to be copied from object
* <code>src</code> to object <code>dst</code> (as in an array
* copy). Thus, <code>dst</code> is the mutated object. Take
* appropriate write barrier actions.<p>
*
* @param src The source array
* @param srcOffset The starting source offset
* @param dst The destination array
* @param dstOffset The starting destination offset
* @param bytes The number of bytes to be copied
* @return True if the update was performed by the barrier, false if
* left to the caller (always false in this case).
*/
public boolean byteBulkCopy(ObjectReference src, Offset srcOffset, ObjectReference dst, Offset dstOffset, int bytes) {
// Either: bulk copy is supported and this is overridden, or
// write barriers are not used and this is never called
if (VM.VERIFY_ASSERTIONS) VM.assertions._assert(false);
return false;
}
/**
* Write a char. Take appropriate write barrier actions.<p>
*
* <b>By default do nothing, override if appropriate.</b>
*
* @param src The object into which the new reference will be stored
* @param slot The address into which the new reference will be
* stored.
* @param value The value of the new char
* @param metaDataA A value that assists the host VM in creating a store
* @param metaDataB A value that assists the host VM in creating a store
* @param mode The context in which the store occurred
*/
public void charWrite(ObjectReference src, Address slot, char value, Word metaDataA, Word metaDataB, int mode) {
// Either: write barriers are used and this is overridden, or
// write barriers are not used and this is never called
if (VM.VERIFY_ASSERTIONS) VM.assertions._assert(false);
}
/**
* Read a char. Take appropriate read barrier action, and
* return the value that was read.<p> This is a <b>substituting<b>
* barrier. The call to this barrier takes the place of a load.<p>
*
* @param src The object reference holding the field being read.
* @param slot The address of the slot being read.
* @param metaDataA A value that assists the host VM in creating a load
* @param metaDataB A value that assists the host VM in creating a load
* @param mode The context in which the load occurred
* @return The char that was read.
*/
@Inline
public char charRead(ObjectReference src, Address slot, Word metaDataA, Word metaDataB, int mode) {
// Either: read barriers are used and this is overridden, or
// read barriers are not used and this is never called
if (VM.VERIFY_ASSERTIONS) VM.assertions._assert(false);
return 0;
}
/**
* A number of chars are about to be copied from object
* <code>src</code> to object <code>dst</code> (as in an array
* copy). Thus, <code>dst</code> is the mutated object. Take
* appropriate write barrier actions.<p>
*
* @param src The source array
* @param srcOffset The starting source offset
* @param dst The destination array
* @param dstOffset The starting destination offset
* @param bytes The number of bytes to be copied
* @return True if the update was performed by the barrier, false if
* left to the caller (always false in this case).
*/
public boolean charBulkCopy(ObjectReference src, Offset srcOffset, ObjectReference dst, Offset dstOffset, int bytes) {
// Either: bulk copy is supported and this is overridden, or
// write barriers are not used and this is never called
if (VM.VERIFY_ASSERTIONS) VM.assertions._assert(false);
return false;
}
/**
* Write a short. Take appropriate write barrier actions.<p>
*
* <b>By default do nothing, override if appropriate.</b>
*
* @param src The object into which the new reference will be stored
* @param slot The address into which the new reference will be
* stored.
* @param value The value of the new short
* @param metaDataA A value that assists the host VM in creating a store
* @param metaDataB A value that assists the host VM in creating a store
* @param mode The context in which the store occurred
*/
public void shortWrite(ObjectReference src, Address slot, short value, Word metaDataA, Word metaDataB, int mode) {
// Either: write barriers are used and this is overridden, or
// write barriers are not used and this is never called
if (VM.VERIFY_ASSERTIONS) VM.assertions._assert(false);
}
/**
* Read a short. Take appropriate read barrier action, and
* return the value that was read.<p> This is a <b>substituting<b>
* barrier. The call to this barrier takes the place of a load.<p>
*
* @param src The object reference holding the field being read.
* @param slot The address of the slot being read.
* @param metaDataA A value that assists the host VM in creating a load
* @param metaDataB A value that assists the host VM in creating a load
* @param mode The context in which the load occurred
* @return The short that was read.
*/
@Inline
public short shortRead(ObjectReference src, Address slot, Word metaDataA, Word metaDataB, int mode) {
// Either: read barriers are used and this is overridden, or
// read barriers are not used and this is never called
if (VM.VERIFY_ASSERTIONS) VM.assertions._assert(false);
return 0;
}
/**
* A number of shorts are about to be copied from object
* <code>src</code> to object <code>dst</code> (as in an array
* copy). Thus, <code>dst</code> is the mutated object. Take
* appropriate write barrier actions.<p>
*
* @param src The source array
* @param srcOffset The starting source offset
* @param dst The destination array
* @param dstOffset The starting destination offset
* @param bytes The number of bytes to be copied
* @return True if the update was performed by the barrier, false if
* left to the caller (always false in this case).
*/
public boolean shortBulkCopy(ObjectReference src, Offset srcOffset, ObjectReference dst, Offset dstOffset, int bytes) {
// Either: bulk copy is supported and this is overridden, or
// write barriers are not used and this is never called
if (VM.VERIFY_ASSERTIONS) VM.assertions._assert(false);
return false;
}
/**
* Write a int. Take appropriate write barrier actions.<p>
*
* <b>By default do nothing, override if appropriate.</b>
*
* @param src The object into which the new reference will be stored
* @param slot The address into which the new reference will be
* stored.
* @param value The value of the new int
* @param metaDataA A value that assists the host VM in creating a store
* @param metaDataB A value that assists the host VM in creating a store
* @param mode The context in which the store occurred
*/
public void intWrite(ObjectReference src, Address slot, int value, Word metaDataA, Word metaDataB, int mode) {
// Either: write barriers are used and this is overridden, or
// write barriers are not used and this is never called
if (VM.VERIFY_ASSERTIONS) VM.assertions._assert(false);
}
/**
* Read a int. Take appropriate read barrier action, and
* return the value that was read.<p> This is a <b>substituting<b>
* barrier. The call to this barrier takes the place of a load.<p>
*
* @param src The object reference holding the field being read.
* @param slot The address of the slot being read.
* @param metaDataA A value that assists the host VM in creating a load
* @param metaDataB A value that assists the host VM in creating a load
* @param mode The context in which the load occurred
* @return The int that was read.
*/
@Inline
public int intRead(ObjectReference src, Address slot, Word metaDataA, Word metaDataB, int mode) {
// Either: read barriers are used and this is overridden, or
// read barriers are not used and this is never called
if (VM.VERIFY_ASSERTIONS) VM.assertions._assert(false);
return 0;
}
/**
* A number of ints are about to be copied from object
* <code>src</code> to object <code>dst</code> (as in an array
* copy). Thus, <code>dst</code> is the mutated object. Take
* appropriate write barrier actions.<p>
*
* @param src The source array
* @param srcOffset The starting source offset
* @param dst The destination array
* @param dstOffset The starting destination offset
* @param bytes The number of bytes to be copied
* @return True if the update was performed by the barrier, false if
* left to the caller (always false in this case).
*/
public boolean intBulkCopy(ObjectReference src, Offset srcOffset, ObjectReference dst, Offset dstOffset, int bytes) {
// Either: bulk copy is supported and this is overridden, or
// write barriers are not used and this is never called
if (VM.VERIFY_ASSERTIONS) VM.assertions._assert(false);
return false;
}
/**
* Attempt to atomically exchange the value in the given slot
* with the passed replacement value.
*
* <b>By default do nothing, override if appropriate.</b>
*
* @param src The object into which the value will be stored
* @param slot The address into which the value will be
* stored.
* @param old The old int to be swapped out
* @param value The new int
* @param metaDataA A value that assists the host VM in creating a store
* @param metaDataB A value that assists the host VM in creating a store
* @param mode The context in which the store occurred
* @return True if the swap was successful.
*/
public boolean intTryCompareAndSwap(ObjectReference src, Address slot, int old, int value, Word metaDataA, Word metaDataB, int mode) {
// Either: write barriers are used and this is overridden, or
// write barriers are not used and this is never called
if (VM.VERIFY_ASSERTIONS) VM.assertions._assert(false);
return false;
}
/**
* Write a long. Take appropriate write barrier actions.<p>
*
* <b>By default do nothing, override if appropriate.</b>
*
* @param src The object into which the new reference will be stored
* @param slot The address into which the new reference will be
* stored.
* @param value The value of the new long
* @param metaDataA A value that assists the host VM in creating a store
* @param metaDataB A value that assists the host VM in creating a store
* @param mode The context in which the store occurred
*/
public void longWrite(ObjectReference src, Address slot, long value, Word metaDataA, Word metaDataB, int mode) {
// Either: write barriers are used and this is overridden, or
// write barriers are not used and this is never called
if (VM.VERIFY_ASSERTIONS) VM.assertions._assert(false);
}
/**
* Read a long. Take appropriate read barrier action, and
* return the value that was read.<p> This is a <b>substituting<b>
* barrier. The call to this barrier takes the place of a load.<p>
*
* @param src The object reference holding the field being read.
* @param slot The address of the slot being read.
* @param metaDataA A value that assists the host VM in creating a load
* @param metaDataB A value that assists the host VM in creating a load
* @param mode The context in which the load occurred
* @return The long that was read.
*/
@Inline
public long longRead(ObjectReference src, Address slot, Word metaDataA, Word metaDataB, int mode) {
// Either: read barriers are used and this is overridden, or
// read barriers are not used and this is never called
if (VM.VERIFY_ASSERTIONS) VM.assertions._assert(false);
return 0;
}
/**
* A number of longs are about to be copied from object
* <code>src</code> to object <code>dst</code> (as in an array
* copy). Thus, <code>dst</code> is the mutated object. Take
* appropriate write barrier actions.<p>
*
* @param src The source array
* @param srcOffset The starting source offset
* @param dst The destination array
* @param dstOffset The starting destination offset
* @param bytes The number of bytes to be copied
* @return True if the update was performed by the barrier, false if
* left to the caller (always false in this case).
*/
public boolean longBulkCopy(ObjectReference src, Offset srcOffset, ObjectReference dst, Offset dstOffset, int bytes) {
// Either: bulk copy is supported and this is overridden, or
// write barriers are not used and this is never called
if (VM.VERIFY_ASSERTIONS) VM.assertions._assert(false);
return false;
}
/**
* Attempt to atomically exchange the value in the given slot
* with the passed replacement value.
*
* <b>By default do nothing, override if appropriate.</b>
*
* @param src The object into which the value will be stored
* @param slot The address into which the value will be
* stored.
* @param old The old long to be swapped out
* @param value The new long
* @param metaDataA A value that assists the host VM in creating a store
* @param metaDataB A value that assists the host VM in creating a store
* @param mode The context in which the store occurred
* @return True if the swap was successful.
*/
public boolean longTryCompareAndSwap(ObjectReference src, Address slot, long old, long value, Word metaDataA, Word metaDataB, int mode) {
// Either: write barriers are used and this is overridden, or
// write barriers are not used and this is never called
if (VM.VERIFY_ASSERTIONS) VM.assertions._assert(false);
return false;
}
/**
* Write a float. Take appropriate write barrier actions.<p>
*
* <b>By default do nothing, override if appropriate.</b>
*
* @param src The object into which the new reference will be stored
* @param slot The address into which the new reference will be
* stored.
* @param value The value of the new float
* @param metaDataA A value that assists the host VM in creating a store
* @param metaDataB A value that assists the host VM in creating a store
* @param mode The context in which the store occurred
*/
public void floatWrite(ObjectReference src, Address slot, float value, Word metaDataA, Word metaDataB, int mode) {
// Either: write barriers are used and this is overridden, or
// write barriers are not used and this is never called
if (VM.VERIFY_ASSERTIONS) VM.assertions._assert(false);
}
/**
* Read a float. Take appropriate read barrier action, and
* return the value that was read.<p> This is a <b>substituting<b>
* barrier. The call to this barrier takes the place of a load.<p>
*
* @param src The object reference holding the field being read.
* @param slot The address of the slot being read.
* @param metaDataA A value that assists the host VM in creating a load
* @param metaDataB A value that assists the host VM in creating a load
* @param mode The context in which the load occurred
* @return The float that was read.
*/
@Inline
public float floatRead(ObjectReference src, Address slot, Word metaDataA, Word metaDataB, int mode) {
// Either: read barriers are used and this is overridden, or
// read barriers are not used and this is never called
if (VM.VERIFY_ASSERTIONS) VM.assertions._assert(false);
return 0;
}
/**
* A number of floats are about to be copied from object
* <code>src</code> to object <code>dst</code> (as in an array
* copy). Thus, <code>dst</code> is the mutated object. Take
* appropriate write barrier actions.<p>
*
* @param src The source array
* @param srcOffset The starting source offset
* @param dst The destination array
* @param dstOffset The starting destination offset
* @param bytes The number of bytes to be copied
* @return True if the update was performed by the barrier, false if
* left to the caller (always false in this case).
*/
public boolean floatBulkCopy(ObjectReference src, Offset srcOffset, ObjectReference dst, Offset dstOffset, int bytes) {
// Either: bulk copy is supported and this is overridden, or
// write barriers are not used and this is never called
if (VM.VERIFY_ASSERTIONS) VM.assertions._assert(false);
return false;
}
/**
* Write a double. Take appropriate write barrier actions.<p>
*
* <b>By default do nothing, override if appropriate.</b>
*
* @param src The object into which the new reference will be stored
* @param slot The address into which the new reference will be
* stored.
* @param value The value of the new double
* @param metaDataA A value that assists the host VM in creating a store
* @param metaDataB A value that assists the host VM in creating a store
* @param mode The context in which the store occurred
*/
public void doubleWrite(ObjectReference src, Address slot, double value, Word metaDataA, Word metaDataB, int mode) {
// Either: write barriers are used and this is overridden, or
// write barriers are not used and this is never called
if (VM.VERIFY_ASSERTIONS) VM.assertions._assert(false);
}
/**
* Read a double. Take appropriate read barrier action, and
* return the value that was read.<p> This is a <b>substituting<b>
* barrier. The call to this barrier takes the place of a load.<p>
*
* @param src The object reference holding the field being read.
* @param slot The address of the slot being read.
* @param metaDataA A value that assists the host VM in creating a load
* @param metaDataB A value that assists the host VM in creating a load
* @param mode The context in which the load occurred
* @return The double that was read.
*/
@Inline
public double doubleRead(ObjectReference src, Address slot, Word metaDataA, Word metaDataB, int mode) {
// Either: read barriers are used and this is overridden, or
// read barriers are not used and this is never called
if (VM.VERIFY_ASSERTIONS) VM.assertions._assert(false);
return 0;
}
/**
* A number of doubles are about to be copied from object
* <code>src</code> to object <code>dst</code> (as in an array
* copy). Thus, <code>dst</code> is the mutated object. Take
* appropriate write barrier actions.<p>
*
* @param src The source array
* @param srcOffset The starting source offset
* @param dst The destination array
* @param dstOffset The starting destination offset
* @param bytes The number of bytes to be copied
* @return True if the update was performed by the barrier, false if
* left to the caller (always false in this case).
*/
public boolean doubleBulkCopy(ObjectReference src, Offset srcOffset, ObjectReference dst, Offset dstOffset, int bytes) {
// Either: bulk copy is supported and this is overridden, or
// write barriers are not used and this is never called
if (VM.VERIFY_ASSERTIONS) VM.assertions._assert(false);
return false;
}
/**
* Write a Word. Take appropriate write barrier actions.<p>
*
* <b>By default do nothing, override if appropriate.</b>
*
* @param src The object into which the new reference will be stored
* @param slot The address into which the new reference will be
* stored.
* @param value The value of the new Word
* @param metaDataA A value that assists the host VM in creating a store
* @param metaDataB A value that assists the host VM in creating a store
* @param mode The context in which the store occurred
*/
public void wordWrite(ObjectReference src, Address slot, Word value, Word metaDataA, Word metaDataB, int mode) {
// Either: write barriers are used and this is overridden, or
// write barriers are not used and this is never called
if (VM.VERIFY_ASSERTIONS) VM.assertions._assert(false);
}
/**
* Read a Word. Take appropriate read barrier action, and
* return the value that was read.<p> This is a <b>substituting<b>
* barrier. The call to this barrier takes the place of a load.<p>
*
* @param src The object reference holding the field being read.
* @param slot The address of the slot being read.
* @param metaDataA A value that assists the host VM in creating a load
* @param metaDataB A value that assists the host VM in creating a load
* @param mode The context in which the load occurred
* @return The Word that was read.
*/
@Inline
public Word wordRead(ObjectReference src, Address slot, Word metaDataA, Word metaDataB, int mode) {
// Either: read barriers are used and this is overridden, or
// read barriers are not used and this is never called
if (VM.VERIFY_ASSERTIONS) VM.assertions._assert(false);
return Word.zero();
}
/**
* A number of Words are about to be copied from object
* <code>src</code> to object <code>dst</code> (as in an array
* copy). Thus, <code>dst</code> is the mutated object. Take
* appropriate write barrier actions.<p>
*
* @param src The source array
* @param srcOffset The starting source offset
* @param dst The destination array
* @param dstOffset The starting destination offset
* @param bytes The number of bytes to be copied
* @return True if the update was performed by the barrier, false if
* left to the caller (always false in this case).
*/
public boolean wordBulkCopy(ObjectReference src, Offset srcOffset, ObjectReference dst, Offset dstOffset, int bytes) {
// Either: bulk copy is supported and this is overridden, or
// write barriers are not used and this is never called
if (VM.VERIFY_ASSERTIONS) VM.assertions._assert(false);
return false;
}
/**
* Attempt to atomically exchange the value in the given slot
* with the passed replacement value.
*
* <b>By default do nothing, override if appropriate.</b>
*
* @param src The object into which the new reference will be stored
* @param slot The address into which the new reference will be
* stored.
* @param old The old Word to be swapped out
* @param value The new Word
* @param metaDataA A value that assists the host VM in creating a store
* @param metaDataB A value that assists the host VM in creating a store
* @param mode The context in which the store occurred
* @return True if the swap was successful.
*/
public boolean wordTryCompareAndSwap(ObjectReference src, Address slot, Word old, Word value, Word metaDataA, Word metaDataB, int mode) {
// Either: write barriers are used and this is overridden, or
// write barriers are not used and this is never called
if (VM.VERIFY_ASSERTIONS) VM.assertions._assert(false);
return false;
}
/**
* Write an Address. Take appropriate write barrier actions.<p>
*
* <b>By default do nothing, override if appropriate.</b>
*
* @param src The object into which the Word will be stored
* @param slot The address into which the Word will be
* stored.
* @param value The value of the new Address
* @param metaDataA A value that assists the host VM in creating a store
* @param metaDataB A value that assists the host VM in creating a store
* @param mode The context in which the store occurred
*/
public void addressWrite(ObjectReference src, Address slot, Address value, Word metaDataA, Word metaDataB, int mode) {
// Either: write barriers are used and this is overridden, or
// write barriers are not used and this is never called
if (VM.VERIFY_ASSERTIONS) VM.assertions._assert(false);
}
/**
* Read an Address. Take appropriate read barrier action, and
* return the value that was read.<p> This is a <b>substituting<b>
* barrier. The call to this barrier takes the place of a load.<p>
*
* @param src The object reference holding the field being read.
* @param slot The address of the slot being read.
* @param metaDataA A value that assists the host VM in creating a load
* @param metaDataB A value that assists the host VM in creating a load
* @param mode The context in which the load occurred
* @return The Address that was read.
*/
@Inline
public Address addressRead(ObjectReference src, Address slot, Word metaDataA, Word metaDataB, int mode) {
// Either: read barriers are used and this is overridden, or
// read barriers are not used and this is never called
if (VM.VERIFY_ASSERTIONS) VM.assertions._assert(false);
return Address.zero();
}
/**
* A number of Addresse's are about to be copied from object
* <code>src</code> to object <code>dst</code> (as in an array
* copy). Thus, <code>dst</code> is the mutated object. Take
* appropriate write barrier actions.<p>
*
* @param src The source array
* @param srcOffset The starting source offset
* @param dst The destination array
* @param dstOffset The starting destination offset
* @param bytes The number of bytes to be copied
* @return True if the update was performed by the barrier, false if
* left to the caller (always false in this case).
*/
public boolean addressBulkCopy(ObjectReference src, Offset srcOffset, ObjectReference dst, Offset dstOffset, int bytes) {
// Either: bulk copy is supported and this is overridden, or
// write barriers are not used and this is never called
if (VM.VERIFY_ASSERTIONS) VM.assertions._assert(false);
return false;
}
/**
* Attempt to atomically exchange the value in the given slot
* with the passed replacement value.
*
* <b>By default do nothing, override if appropriate.</b>
*
* @param src The object into which the Address will be stored
* @param slot The address into which the Address will be
* stored.
* @param old The old Address to be swapped out
* @param value The new Address
* @param metaDataA A value that assists the host VM in creating a store
* @param metaDataB A value that assists the host VM in creating a store
* @param mode The context in which the store occurred
* @return True if the swap was successful.
*/
public boolean addressTryCompareAndSwap(ObjectReference src, Address slot, Address old, Address value, Word metaDataA, Word metaDataB, int mode) {
// Either: write barriers are used and this is overridden, or
// write barriers are not used and this is never called
if (VM.VERIFY_ASSERTIONS) VM.assertions._assert(false);
return false;
}
/**
* Write an Extent. Take appropriate write barrier actions.<p>
*
* <b>By default do nothing, override if appropriate.</b>
*
* @param src The object into which the new reference will be stored
* @param slot The address into which the new reference will be
* stored.
* @param value The value of the new Extent
* @param metaDataA A value that assists the host VM in creating a store
* @param metaDataB A value that assists the host VM in creating a store
* @param mode The context in which the store occurred
*/
public void extentWrite(ObjectReference src, Address slot, Extent value, Word metaDataA, Word metaDataB, int mode) {
// Either: write barriers are used and this is overridden, or
// write barriers are not used and this is never called
if (VM.VERIFY_ASSERTIONS) VM.assertions._assert(false);
}
/**
* Read an Extent. Take appropriate read barrier action, and
* return the value that was read.<p> This is a <b>substituting<b>
* barrier. The call to this barrier takes the place of a load.<p>
*
* @param src The object reference holding the field being read.
* @param slot The address of the slot being read.
* @param metaDataA A value that assists the host VM in creating a load
* @param metaDataB A value that assists the host VM in creating a load
* @param mode The context in which the load occurred
* @return The Extent that was read.
*/
@Inline
public Extent extentRead(ObjectReference src, Address slot, Word metaDataA, Word metaDataB, int mode) {
// Either: read barriers are used and this is overridden, or
// read barriers are not used and this is never called
if (VM.VERIFY_ASSERTIONS) VM.assertions._assert(false);
return Extent.zero();
}
/**
* A number of Extents are about to be copied from object
* <code>src</code> to object <code>dst</code> (as in an array
* copy). Thus, <code>dst</code> is the mutated object. Take
* appropriate write barrier actions.<p>
*
* @param src The source array
* @param srcOffset The starting source offset
* @param dst The destination array
* @param dstOffset The starting destination offset
* @param bytes The number of bytes to be copied
* @return True if the update was performed by the barrier, false if
* left to the caller (always false in this case).
*/
public boolean extentBulkCopy(ObjectReference src, Offset srcOffset, ObjectReference dst, Offset dstOffset, int bytes) {
// Either: bulk copy is supported and this is overridden, or
// write barriers are not used and this is never called
if (VM.VERIFY_ASSERTIONS) VM.assertions._assert(false);
return false;
}
/**
* Write an Offset. Take appropriate write barrier actions.<p>
*
* <b>By default do nothing, override if appropriate.</b>
*
* @param src The object into which the new reference will be stored
* @param slot The address into which the new reference will be
* stored.
* @param value The value of the new Offset
* @param metaDataA A value that assists the host VM in creating a store
* @param metaDataB A value that assists the host VM in creating a store
* @param mode The context in which the store occurred
*/
public void offsetWrite(ObjectReference src, Address slot, Offset value, Word metaDataA, Word metaDataB, int mode) {
// Either: write barriers are used and this is overridden, or
// write barriers are not used and this is never called
if (VM.VERIFY_ASSERTIONS) VM.assertions._assert(false);
}
/**
* Read an Offset. Take appropriate read barrier action, and
* return the value that was read.<p> This is a <b>substituting<b>
* barrier. The call to this barrier takes the place of a load.<p>
*
* @param src The object reference holding the field being read.
* @param slot The address of the slot being read.
* @param metaDataA A value that assists the host VM in creating a load
* @param metaDataB A value that assists the host VM in creating a load
* @param mode The context in which the load occurred
* @return The Offset that was read.
*/
@Inline
public Offset offsetRead(ObjectReference src, Address slot, Word metaDataA, Word metaDataB, int mode) {
// Either: read barriers are used and this is overridden, or
// read barriers are not used and this is never called
if (VM.VERIFY_ASSERTIONS) VM.assertions._assert(false);
return Offset.zero();
}
/**
* A number of Offsets are about to be copied from object
* <code>src</code> to object <code>dst</code> (as in an array
* copy). Thus, <code>dst</code> is the mutated object. Take
* appropriate write barrier actions.<p>
*
* @param src The source array
* @param srcOffset The starting source offset
* @param dst The destination array
* @param dstOffset The starting destination offset
* @param bytes The number of bytes to be copied
* @return True if the update was performed by the barrier, false if
* left to the caller (always false in this case).
*/
public boolean offsetBulkCopy(ObjectReference src, Offset srcOffset, ObjectReference dst, Offset dstOffset, int bytes) {
// Either: bulk copy is supported and this is overridden, or
// write barriers are not used and this is never called
if (VM.VERIFY_ASSERTIONS) VM.assertions._assert(false);
return false;
}
/**
* Write an object reference. Take appropriate write barrier actions.<p>
*
* <b>By default do nothing, override if appropriate.</b>
*
* @param src The object into which the new reference will be stored
* @param slot The address into which the new reference will be
* stored.
* @param value The value of the new reference
* @param metaDataA A value that assists the host VM in creating a store
* @param metaDataB A value that assists the host VM in creating a store
* @param mode The context in which the store occurred
*/
public void objectReferenceWrite(ObjectReference src, Address slot, ObjectReference value, Word metaDataA, Word metaDataB, int mode) {
// Either: write barriers are used and this is overridden, or
// write barriers are not used and this is never called
if (VM.VERIFY_ASSERTIONS) VM.assertions._assert(false);
}
/**
* Read an object reference. Take appropriate read barrier action, and
* return the value that was read.<p> This is a <b>substituting<b>
* barrier. The call to this barrier takes the place of a load.<p>
*
* @param src The object reference holding the field being read.
* @param slot The address of the slot being read.
* @param metaDataA A value that assists the host VM in creating a load
* @param metaDataB A value that assists the host VM in creating a load
* @param mode The context in which the load occurred
* @return The reference that was read.
*/
@Inline
public ObjectReference objectReferenceRead(ObjectReference src, Address slot, Word metaDataA, Word metaDataB, int mode) {
// Either: read barriers are used and this is overridden, or
// read barriers are not used and this is never called
if (VM.VERIFY_ASSERTIONS) VM.assertions._assert(false);
return ObjectReference.nullReference();
}
/**
* A number of references are about to be copied from object
* <code>src</code> to object <code>dst</code> (as in an array
* copy). Thus, <code>dst</code> is the mutated object. Take
* appropriate write barrier actions.<p>
*
* @param src The source array
* @param srcOffset The starting source offset
* @param dst The destination array
* @param dstOffset The starting destination offset
* @param bytes The number of bytes to be copied
* @return True if the update was performed by the barrier, false if
* left to the caller (always false in this case).
*/
public boolean objectReferenceBulkCopy(ObjectReference src, Offset srcOffset, ObjectReference dst, Offset dstOffset, int bytes) {
// Either: bulk copy is supported and this is overridden, or
// write barriers are not used and this is never called
if (VM.VERIFY_ASSERTIONS) VM.assertions._assert(false);
return false;
}
/**
* A new reference is about to be created in a location that is not
* a regular heap object. Take appropriate write barrier actions.<p>
*
* <b>By default do nothing, override if appropriate.</b>
*
* @param slot The address into which the new reference will be
* stored.
* @param tgt The target of the new reference
* @param metaDataA A value that assists the host VM in creating a store
* @param metaDataB A value that assists the host VM in creating a store
*/
public void objectReferenceNonHeapWrite(Address slot, ObjectReference tgt, Word metaDataA, Word metaDataB) {
// Either: write barriers are used and this is overridden, or
// write barriers are not used and this is never called
if (VM.VERIFY_ASSERTIONS) VM.assertions._assert(false);
}
/**
* Read an object reference. Take appropriate read barrier action, and
* return the value that was read.<p> This is a <b>substituting<b>
* barrier. The call to this barrier takes the place of a load.<p>
*
* @param slot The address of the slot being read.
* @param metaDataA A value that assists the host VM in creating a load
* @param metaDataB A value that assists the host VM in creating a load
* @return The reference that was read.
*/
@Inline
public ObjectReference objectReferenceNonHeapRead(Address slot, Word metaDataA, Word metaDataB) {
// Either: read barriers are used and this is overridden, or
// read barriers are not used and this is never called
if (VM.VERIFY_ASSERTIONS) VM.assertions._assert(false);
return ObjectReference.nullReference();
}
/**
* Attempt to atomically exchange the value in the given slot
* with the passed replacement value. If a new reference is
* created, we must then take appropriate write barrier actions.<p>
*
* <b>By default do nothing, override if appropriate.</b>
*
* @param src The object into which the new reference will be stored
* @param slot The address into which the new reference will be
* stored.
* @param old The old reference to be swapped out
* @param tgt The target of the new reference
* @param metaDataA A value that assists the host VM in creating a store
* @param metaDataB A value that assists the host VM in creating a store
* @param mode The context in which the store occurred
* @return True if the swap was successful.
*/
public boolean objectReferenceTryCompareAndSwap(ObjectReference src, Address slot, ObjectReference old, ObjectReference tgt, Word metaDataA, Word metaDataB, int mode) {
// Either: write barriers are used and this is overridden, or
// write barriers are not used and this is never called
if (VM.VERIFY_ASSERTIONS) VM.assertions._assert(false);
return false;
}
/**
* Flush mutator context, in response to a requestMutatorFlush.
* Also called by the default implementation of deinitMutator.
*/
public void flush() {
flushRememberedSets();
smcode.flush();
nonmove.flush();
}
/**
* Flush per-mutator remembered sets into the global remset pool.
*/
public void flushRememberedSets() {
// Either: write barriers are used and this is overridden, or
// write barriers are not used and this is a no-op
}
/**
* Assert that the remsets have been flushed. This is critical to
* correctness. We need to maintain the invariant that remset entries
* do not accrue during GC. If the host JVM generates barrier entires
* it is its own responsibility to ensure that they are flushed before
* returning to MMTk.
*/
public void assertRemsetsFlushed() {
// Either: write barriers are used and this is overridden, or
// write barriers are not used and this is a no-op
}
/***********************************************************************
*
* Miscellaneous
*/
/** @return the <code>Log</code> instance for this PlanLocal */
public final Log getLog() {
return log;
}
/** @return the unique identifier for this mutator context. */
@Inline
public int getId() { return id; }
}