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package sun.jvm.hotspot.runtime;

import java.io.*;
import java.util.*;
import sun.jvm.hotspot.debugger.*;
import sun.jvm.hotspot.oops.*;
import sun.jvm.hotspot.types.*;

ThreadLocalAllocBuffer: a descriptor for thread-local storage used by the threads for allocation.

It is thread-private at any time, but maybe multiplexed over time across multiple threads.

/** <P> ThreadLocalAllocBuffer: a descriptor for thread-local storage used by the threads for allocation. </P> <P> It is thread-private at any time, but maybe multiplexed over time across multiple threads. </P> */
public class ThreadLocalAllocBuffer extends VMObject { private static AddressField startField; private static AddressField topField; private static AddressField endField; private static CIntegerField desired_sizeField; static { VM.registerVMInitializedObserver(new Observer() { public void update(Observable o, Object data) { initialize(VM.getVM().getTypeDataBase()); } }); } private static synchronized void initialize(TypeDataBase db) { Type type = db.lookupType("ThreadLocalAllocBuffer"); startField = type.getAddressField("_start"); topField = type.getAddressField("_top"); endField = type.getAddressField("_end"); desired_sizeField = type.getCIntegerField("_desired_size"); } public ThreadLocalAllocBuffer(Address addr) { super(addr); } public Address start() { return startField.getValue(addr); } public Address end() { return endField.getValue(addr); } public Address top() { return topField.getValue(addr); } public Address hardEnd() { return end().addOffsetTo(alignmentReserve()); } private long alignmentReserve() { return Oop.alignObjectSize(endReserve()); } private long endReserve() { long minFillerArraySize = Array.baseOffsetInBytes(BasicType.T_INT); long reserveForAllocationPrefetch = VM.getVM().getReserveForAllocationPrefetch(); long heapWordSize = VM.getVM().getHeapWordSize(); return Math.max(minFillerArraySize, reserveForAllocationPrefetch * heapWordSize); }
Support for iteration over heap -- not sure how this will interact with GC in reflective system, but necessary for the debugging mechanism
/** Support for iteration over heap -- not sure how this will interact with GC in reflective system, but necessary for the debugging mechanism */
public OopHandle startAsOopHandle() { return startField.getOopHandle(addr); }
Support for iteration over heap -- not sure how this will interact with GC in reflective system, but necessary for the debugging mechanism
/** Support for iteration over heap -- not sure how this will interact with GC in reflective system, but necessary for the debugging mechanism */
public OopHandle nextOopHandle(OopHandle handle, long size) { return handle.addOffsetToAsOopHandle(size); } // public int size(); // FIXME: must adjust this to be in bytes // public int availableSize(); // FIXME: must adjust this to be in bytes public void print() { printOn(System.out); } public boolean contains(Address p) { if (top() == null) { return false; } return (start().lessThanOrEqual(p) && top().greaterThan(p)); } public void printOn(PrintStream tty) { tty.println(" [" + start() + "," + top() + "," + end() + ",{" + hardEnd() + "})"); } }