src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/compiler/ImmutableOopMapSet.java - platform/libcore - Git at Google

 /*
  * Copyright (c) 2000, 2008, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.
  *
  * This code is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  *
  */

 package sun.jvm.hotspot.compiler;

 import java.util.*;

 import sun.jvm.hotspot.code.*;
 import sun.jvm.hotspot.debugger.*;
 import sun.jvm.hotspot.runtime.*;
 import sun.jvm.hotspot.types.*;
 import sun.jvm.hotspot.utilities.*;

 public class ImmutableOopMapSet extends VMObject {
   private static final boolean DEBUG = System.getProperty("sun.jvm.hotspot.compiler.ImmutableOopMapSet.DEBUG") != null;

   private static CIntegerField countField;
   private static CIntegerField sizeField;
   private static AddressField omDataField;
   private static int REG_COUNT;
   private static int SAVED_ON_ENTRY_REG_COUNT;
   private static int C_SAVED_ON_ENTRY_REG_COUNT;
   private static long classSize;

   private static class MyVisitor implements OopMapVisitor {
     private AddressVisitor addressVisitor;

     public MyVisitor(AddressVisitor oopVisitor) {
       setAddressVisitor(oopVisitor);
     }

     public void setAddressVisitor(AddressVisitor addressVisitor) {
       this.addressVisitor = addressVisitor;
     }

     public void visitOopLocation(Address oopAddr) {
       addressVisitor.visitAddress(oopAddr);
     }

     public void visitDerivedOopLocation(Address baseOopAddr, Address derivedOopAddr) {
       if (VM.getVM().isClientCompiler()) {
         Assert.that(false, "should not reach here");
       } else if (VM.getVM().isServerCompiler() &&
           VM.getVM().useDerivedPointerTable()) {
         Assert.that(false, "FIXME: add derived pointer table");
       }
     }

     public void visitNarrowOopLocation(Address narrowOopAddr) {
       addressVisitor.visitCompOopAddress(narrowOopAddr);
     }
   }

   static {
     VM.registerVMInitializedObserver(new Observer() {
       public void update(Observable o, Object data) {
         initialize(VM.getVM().getTypeDataBase());
       }
     });
   }

   private static void initialize(TypeDataBase db) {
     Type type = db.lookupType("ImmutableOopMapSet");

     countField = type.getCIntegerField("_count");
     sizeField = type.getCIntegerField("_size");
     classSize = type.getSize();

     if (!VM.getVM().isCore()) {
       REG_COUNT = db.lookupIntConstant("REG_COUNT").intValue();
       if (VM.getVM().isServerCompiler()) {
         SAVED_ON_ENTRY_REG_COUNT = (int) db.lookupIntConstant("SAVED_ON_ENTRY_REG_COUNT").intValue();
         C_SAVED_ON_ENTRY_REG_COUNT = (int) db.lookupIntConstant("C_SAVED_ON_ENTRY_REG_COUNT").intValue();
       }
     }
   }

   public ImmutableOopMapSet(Address addr) {
     super(addr);
   }

   /**
    * Returns the number of OopMaps in this ImmutableOopMapSet
    */
   public int getCount() { return (int) countField.getValue(addr); }

   private Address dataStart() {
     return (pairStart().addOffsetTo(ImmutableOopMapPair.classSize() * getCount()));
   }

   private Address pairStart() {
     return addr.addOffsetTo(ImmutableOopMapSet.classSize);
   }

   public ImmutableOopMapPair pairAt(int index) {
     Assert.that((index >= 0) && (index < getCount()), "bad index");
     return new ImmutableOopMapPair(pairStart().addOffsetTo(index * ImmutableOopMapPair.classSize()));
   }

   /**
    * returns the OopMap at a given index
    */
   public ImmutableOopMap getMapAt(int index) {
     if (Assert.ASSERTS_ENABLED) {
       Assert.that((index >= 0) && (index <= getCount()), "bad index");
     }

     ImmutableOopMapPair immutableOopMapPair = pairAt(index);
     return getMap(immutableOopMapPair);
   }

   public ImmutableOopMap findMapAtOffset(long pcOffset, boolean debugging) {
     int i;
     int len = getCount();
     if (Assert.ASSERTS_ENABLED) {
       Assert.that(len > 0, "must have pointer maps");
     }

     // Scan through oopmaps. Stop when current offset is either equal or greater
     // than the one we are looking for.
     for (i = 0; i < len; i++) {
       if (pairAt(i).getPC() >= pcOffset) {
         break;
       }
     }

     if (!debugging) {
       if (Assert.ASSERTS_ENABLED) {
         Assert.that(i < len, "oopmap not found for pcOffset = " + pcOffset + "; len = " + len);
         Assert.that(pairAt(i).getPC() == pcOffset, "oopmap not found");
       }
     } else {
       if (i == len) {
         if (DEBUG) {
           System.out.println("can't find oopmap at " + pcOffset);
           System.out.print("Oopmap offsets are [ ");
           for (i = 0; i < len; i++) {
             System.out.print(pairAt(i).getPC());
           }
           System.out.println("]");
         }
         i = len - 1;
         return getMapAt(i);
       }
     }

     ImmutableOopMap m = getMapAt(i);
     return m;
   }

   /**
    * Visitation -- iterates through the frame for a compiled method.
    * This is a very generic mechanism that requires the Address to be
    * dereferenced by the callee. Other, more specialized, visitation
    * mechanisms are given below.
    */
   public static void oopsDo(Frame fr, CodeBlob cb, RegisterMap regMap, AddressVisitor oopVisitor, boolean debugging) {
     allDo(fr, cb, regMap, new MyVisitor(oopVisitor), debugging);
   }

   /**
    * Note that there are 4 required AddressVisitors: one for oops,
    * one for derived oops, one for values, and one for dead values
    */
   public static void allDo(Frame fr, CodeBlob cb, RegisterMap regMap, OopMapVisitor visitor, boolean debugging) {
     if (Assert.ASSERTS_ENABLED) {
       CodeBlob tmpCB = VM.getVM().getCodeCache().findBlob(fr.getPC());
       Assert.that(tmpCB != null && cb.equals(tmpCB), "wrong codeblob passed in");
     }

     ImmutableOopMapSet maps = cb.getOopMaps();
     ImmutableOopMap map = cb.getOopMapForReturnAddress(fr.getPC(), debugging);
     if (Assert.ASSERTS_ENABLED) {
       Assert.that(map != null, "no ptr map found");
     }

     // handle derived pointers first (otherwise base pointer may be
     // changed before derived pointer offset has been collected)
     OopMapValue omv;
     {
       for (OopMapStream oms = new OopMapStream(map, OopMapValue.OopTypes.DERIVED_OOP_VALUE); !oms.isDone(); oms.next()) {
         if (VM.getVM().isClientCompiler()) {
           Assert.that(false, "should not reach here");
         }
         omv = oms.getCurrent();
         Address loc = fr.oopMapRegToLocation(omv.getReg(), regMap);
         if (loc != null) {
           Address baseLoc = fr.oopMapRegToLocation(omv.getContentReg(), regMap);
           Address derivedLoc = loc;
           visitor.visitDerivedOopLocation(baseLoc, derivedLoc);
         }
       }
     }

     // We want narow oop and oop oop_types
     OopMapValue.OopTypes[] values = new OopMapValue.OopTypes[] {
         OopMapValue.OopTypes.OOP_VALUE, OopMapValue.OopTypes.NARROWOOP_VALUE
     };

     {
       for (OopMapStream oms = new OopMapStream(map, values); !oms.isDone(); oms.next()) {
         omv = oms.getCurrent();
         Address loc = fr.oopMapRegToLocation(omv.getReg(), regMap);
         if (loc != null) {
           if (omv.getType() == OopMapValue.OopTypes.OOP_VALUE) {
             // This assert commented out because this will be useful
             // to detect in the debugging system
             // assert(Universe::is_heap_or_null(*loc), "found non oop pointer");
             visitor.visitOopLocation(loc);
           } else if (omv.getType() == OopMapValue.OopTypes.NARROWOOP_VALUE) {
             visitor.visitNarrowOopLocation(loc);
           }
         }
       }
     }
   }

   /**
    * Update callee-saved register info for the following frame.
    * Should only be called in non-core builds.
    */
   public static void updateRegisterMap(Frame fr, CodeBlob cb, RegisterMap regMap, boolean debugging) {
     if (Assert.ASSERTS_ENABLED) {
       Assert.that(!VM.getVM().isCore(), "non-core builds only");
     }

     if (!VM.getVM().isDebugging()) {
       if (Assert.ASSERTS_ENABLED) {
         ImmutableOopMapSet maps = cb.getOopMaps();
         Assert.that((maps != null) && (maps.getCount() > 0), "found null or empty ImmutableOopMapSet for CodeBlob");
       }
     } else {
       // Hack for some topmost frames that have been found with empty
       // OopMapSets. (Actually have not seen the null case, but don't
       // want to take any chances.) See HSDB.showThreadStackMemory().
       ImmutableOopMapSet maps = cb.getOopMaps();
       if ((maps == null) || (maps.getCount() == 0)) {
         return;
       }
     }

     // Check if caller must update oop argument
     regMap.setIncludeArgumentOops(cb.callerMustGCArguments());

     int nofCallee = 0;
     Address[] locs = new Address[2 * REG_COUNT + 1];
     VMReg[] regs = new VMReg[2 * REG_COUNT + 1];
     // ("+1" because REG_COUNT might be zero)

     // Scan through oopmap and find location of all callee-saved registers
     // (we do not do update in place, since info could be overwritten)
     ImmutableOopMap map = cb.getOopMapForReturnAddress(fr.getPC(), debugging);
     if (Assert.ASSERTS_ENABLED) {
       Assert.that(map != null, "no ptr map found");
     }

     OopMapValue omv = null;
     for (OopMapStream oms = new OopMapStream(map, OopMapValue.OopTypes.CALLEE_SAVED_VALUE); !oms.isDone(); oms.next()) {
       omv = oms.getCurrent();
       if (Assert.ASSERTS_ENABLED) {
         Assert.that(nofCallee < 2 * REG_COUNT, "overflow");
       }
       regs[nofCallee] = omv.getContentReg();
       locs[nofCallee] = fr.oopMapRegToLocation(omv.getReg(), regMap);
       nofCallee++;
     }

     // Check that runtime stubs save all callee-saved registers
     // After adapter frames were deleted C2 doesn't use callee save registers at present
     if (Assert.ASSERTS_ENABLED) {
       if (VM.getVM().isServerCompiler()) {
         Assert.that(!cb.isRuntimeStub() ||
                 (nofCallee >= SAVED_ON_ENTRY_REG_COUNT || nofCallee >= C_SAVED_ON_ENTRY_REG_COUNT),
             "must save all");
       }
     }

     // Copy found callee-saved register to reg_map
     for (int i = 0; i < nofCallee; i++) {
       regMap.setLocation(regs[i], locs[i]);
     }
   }

   public ImmutableOopMapPair getPairAt(int index) {
     return pairAt(index);
   }

   private int getSize() {
     return (int) sizeField.getValue(addr);
   }

   public ImmutableOopMap getMap(ImmutableOopMapPair pair) {
     Assert.that(pair.getOffset() < getSize(), "boundary check: this: " + this + " offset: " + pair);
     return new ImmutableOopMap(dataStart().addOffsetTo(pair.getOffset()));
   }

   public String toString() {
     StringBuilder builder = new StringBuilder();
     builder.append("Set{ ")
       .append("addr = ").append(addr)
       .append(", count = ").append(getCount())
       .append(", size = ").append(getSize())
       .append(", pairs = [");

     for (int i = 0; i < getCount(); ++i) {
       builder.append(getPairAt(i));
     }

     builder.append("]");
     return builder.toString();
   }
 }
	/*
	* Copyright (c) 2000, 2008, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation.
	*
	* This code is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*
	*/

	package sun.jvm.hotspot.compiler;

	import java.util.*;

	import sun.jvm.hotspot.code.*;
	import sun.jvm.hotspot.debugger.*;
	import sun.jvm.hotspot.runtime.*;
	import sun.jvm.hotspot.types.*;
	import sun.jvm.hotspot.utilities.*;

	public class ImmutableOopMapSet extends VMObject {
	private static final boolean DEBUG = System.getProperty("sun.jvm.hotspot.compiler.ImmutableOopMapSet.DEBUG") != null;

	private static CIntegerField countField;
	private static CIntegerField sizeField;
	private static AddressField omDataField;
	private static int REG_COUNT;
	private static int SAVED_ON_ENTRY_REG_COUNT;
	private static int C_SAVED_ON_ENTRY_REG_COUNT;
	private static long classSize;

	private static class MyVisitor implements OopMapVisitor {
	private AddressVisitor addressVisitor;

	public MyVisitor(AddressVisitor oopVisitor) {
	setAddressVisitor(oopVisitor);
	}

	public void setAddressVisitor(AddressVisitor addressVisitor) {
	this.addressVisitor = addressVisitor;
	}

	public void visitOopLocation(Address oopAddr) {
	addressVisitor.visitAddress(oopAddr);
	}

	public void visitDerivedOopLocation(Address baseOopAddr, Address derivedOopAddr) {
	if (VM.getVM().isClientCompiler()) {
	Assert.that(false, "should not reach here");
	} else if (VM.getVM().isServerCompiler() &&
	VM.getVM().useDerivedPointerTable()) {
	Assert.that(false, "FIXME: add derived pointer table");
	}
	}

	public void visitNarrowOopLocation(Address narrowOopAddr) {
	addressVisitor.visitCompOopAddress(narrowOopAddr);
	}
	}

	static {
	VM.registerVMInitializedObserver(new Observer() {
	public void update(Observable o, Object data) {
	initialize(VM.getVM().getTypeDataBase());
	}
	});
	}

	private static void initialize(TypeDataBase db) {
	Type type = db.lookupType("ImmutableOopMapSet");

	countField = type.getCIntegerField("_count");
	sizeField = type.getCIntegerField("_size");
	classSize = type.getSize();

	if (!VM.getVM().isCore()) {
	REG_COUNT = db.lookupIntConstant("REG_COUNT").intValue();
	if (VM.getVM().isServerCompiler()) {
	SAVED_ON_ENTRY_REG_COUNT = (int) db.lookupIntConstant("SAVED_ON_ENTRY_REG_COUNT").intValue();
	C_SAVED_ON_ENTRY_REG_COUNT = (int) db.lookupIntConstant("C_SAVED_ON_ENTRY_REG_COUNT").intValue();
	}
	}
	}

	public ImmutableOopMapSet(Address addr) {
	super(addr);
	}

	/**
	* Returns the number of OopMaps in this ImmutableOopMapSet
	*/
	public int getCount() { return (int) countField.getValue(addr); }

	private Address dataStart() {
	return (pairStart().addOffsetTo(ImmutableOopMapPair.classSize() * getCount()));
	}

	private Address pairStart() {
	return addr.addOffsetTo(ImmutableOopMapSet.classSize);
	}

	public ImmutableOopMapPair pairAt(int index) {
	Assert.that((index >= 0) && (index < getCount()), "bad index");
	return new ImmutableOopMapPair(pairStart().addOffsetTo(index * ImmutableOopMapPair.classSize()));
	}

	/**
	* returns the OopMap at a given index
	*/
	public ImmutableOopMap getMapAt(int index) {
	if (Assert.ASSERTS_ENABLED) {
	Assert.that((index >= 0) && (index <= getCount()), "bad index");
	}

	ImmutableOopMapPair immutableOopMapPair = pairAt(index);
	return getMap(immutableOopMapPair);
	}

	public ImmutableOopMap findMapAtOffset(long pcOffset, boolean debugging) {
	int i;
	int len = getCount();
	if (Assert.ASSERTS_ENABLED) {
	Assert.that(len > 0, "must have pointer maps");
	}

	// Scan through oopmaps. Stop when current offset is either equal or greater
	// than the one we are looking for.
	for (i = 0; i < len; i++) {
	if (pairAt(i).getPC() >= pcOffset) {
	break;
	}
	}

	if (!debugging) {
	if (Assert.ASSERTS_ENABLED) {
	Assert.that(i < len, "oopmap not found for pcOffset = " + pcOffset + "; len = " + len);
	Assert.that(pairAt(i).getPC() == pcOffset, "oopmap not found");
	}
	} else {
	if (i == len) {
	if (DEBUG) {
	System.out.println("can't find oopmap at " + pcOffset);
	System.out.print("Oopmap offsets are [ ");
	for (i = 0; i < len; i++) {
	System.out.print(pairAt(i).getPC());
	}
	System.out.println("]");
	}
	i = len - 1;
	return getMapAt(i);
	}
	}

	ImmutableOopMap m = getMapAt(i);
	return m;
	}

	/**
	* Visitation -- iterates through the frame for a compiled method.
	* This is a very generic mechanism that requires the Address to be
	* dereferenced by the callee. Other, more specialized, visitation
	* mechanisms are given below.
	*/
	public static void oopsDo(Frame fr, CodeBlob cb, RegisterMap regMap, AddressVisitor oopVisitor, boolean debugging) {
	allDo(fr, cb, regMap, new MyVisitor(oopVisitor), debugging);
	}

	/**
	* Note that there are 4 required AddressVisitors: one for oops,
	* one for derived oops, one for values, and one for dead values
	*/
	public static void allDo(Frame fr, CodeBlob cb, RegisterMap regMap, OopMapVisitor visitor, boolean debugging) {
	if (Assert.ASSERTS_ENABLED) {
	CodeBlob tmpCB = VM.getVM().getCodeCache().findBlob(fr.getPC());
	Assert.that(tmpCB != null && cb.equals(tmpCB), "wrong codeblob passed in");
	}

	ImmutableOopMapSet maps = cb.getOopMaps();
	ImmutableOopMap map = cb.getOopMapForReturnAddress(fr.getPC(), debugging);
	if (Assert.ASSERTS_ENABLED) {
	Assert.that(map != null, "no ptr map found");
	}

	// handle derived pointers first (otherwise base pointer may be
	// changed before derived pointer offset has been collected)
	OopMapValue omv;
	{
	for (OopMapStream oms = new OopMapStream(map, OopMapValue.OopTypes.DERIVED_OOP_VALUE); !oms.isDone(); oms.next()) {
	if (VM.getVM().isClientCompiler()) {
	Assert.that(false, "should not reach here");
	}
	omv = oms.getCurrent();
	Address loc = fr.oopMapRegToLocation(omv.getReg(), regMap);
	if (loc != null) {
	Address baseLoc = fr.oopMapRegToLocation(omv.getContentReg(), regMap);
	Address derivedLoc = loc;
	visitor.visitDerivedOopLocation(baseLoc, derivedLoc);
	}
	}
	}

	// We want narow oop and oop oop_types
	OopMapValue.OopTypes[] values = new OopMapValue.OopTypes[] {
	OopMapValue.OopTypes.OOP_VALUE, OopMapValue.OopTypes.NARROWOOP_VALUE
	};

	{
	for (OopMapStream oms = new OopMapStream(map, values); !oms.isDone(); oms.next()) {
	omv = oms.getCurrent();
	Address loc = fr.oopMapRegToLocation(omv.getReg(), regMap);
	if (loc != null) {
	if (omv.getType() == OopMapValue.OopTypes.OOP_VALUE) {
	// This assert commented out because this will be useful
	// to detect in the debugging system
	// assert(Universe::is_heap_or_null(*loc), "found non oop pointer");
	visitor.visitOopLocation(loc);
	} else if (omv.getType() == OopMapValue.OopTypes.NARROWOOP_VALUE) {
	visitor.visitNarrowOopLocation(loc);
	}
	}
	}
	}
	}

	/**
	* Update callee-saved register info for the following frame.
	* Should only be called in non-core builds.
	*/
	public static void updateRegisterMap(Frame fr, CodeBlob cb, RegisterMap regMap, boolean debugging) {
	if (Assert.ASSERTS_ENABLED) {
	Assert.that(!VM.getVM().isCore(), "non-core builds only");
	}

	if (!VM.getVM().isDebugging()) {
	if (Assert.ASSERTS_ENABLED) {
	ImmutableOopMapSet maps = cb.getOopMaps();
	Assert.that((maps != null) && (maps.getCount() > 0), "found null or empty ImmutableOopMapSet for CodeBlob");
	}
	} else {
	// Hack for some topmost frames that have been found with empty
	// OopMapSets. (Actually have not seen the null case, but don't
	// want to take any chances.) See HSDB.showThreadStackMemory().
	ImmutableOopMapSet maps = cb.getOopMaps();
	if ((maps == null) \|\| (maps.getCount() == 0)) {
	return;
	}
	}

	// Check if caller must update oop argument
	regMap.setIncludeArgumentOops(cb.callerMustGCArguments());

	int nofCallee = 0;
	Address[] locs = new Address[2 * REG_COUNT + 1];
	VMReg[] regs = new VMReg[2 * REG_COUNT + 1];
	// ("+1" because REG_COUNT might be zero)

	// Scan through oopmap and find location of all callee-saved registers
	// (we do not do update in place, since info could be overwritten)
	ImmutableOopMap map = cb.getOopMapForReturnAddress(fr.getPC(), debugging);
	if (Assert.ASSERTS_ENABLED) {
	Assert.that(map != null, "no ptr map found");
	}

	OopMapValue omv = null;
	for (OopMapStream oms = new OopMapStream(map, OopMapValue.OopTypes.CALLEE_SAVED_VALUE); !oms.isDone(); oms.next()) {
	omv = oms.getCurrent();
	if (Assert.ASSERTS_ENABLED) {
	Assert.that(nofCallee < 2 * REG_COUNT, "overflow");
	}
	regs[nofCallee] = omv.getContentReg();
	locs[nofCallee] = fr.oopMapRegToLocation(omv.getReg(), regMap);
	nofCallee++;
	}

	// Check that runtime stubs save all callee-saved registers
	// After adapter frames were deleted C2 doesn't use callee save registers at present
	if (Assert.ASSERTS_ENABLED) {
	if (VM.getVM().isServerCompiler()) {
	Assert.that(!cb.isRuntimeStub() \|\|
	(nofCallee >= SAVED_ON_ENTRY_REG_COUNT \|\| nofCallee >= C_SAVED_ON_ENTRY_REG_COUNT),
	"must save all");
	}
	}

	// Copy found callee-saved register to reg_map
	for (int i = 0; i < nofCallee; i++) {
	regMap.setLocation(regs[i], locs[i]);
	}
	}

	public ImmutableOopMapPair getPairAt(int index) {
	return pairAt(index);
	}

	private int getSize() {
	return (int) sizeField.getValue(addr);
	}

	public ImmutableOopMap getMap(ImmutableOopMapPair pair) {
	Assert.that(pair.getOffset() < getSize(), "boundary check: this: " + this + " offset: " + pair);
	return new ImmutableOopMap(dataStart().addOffsetTo(pair.getOffset()));
	}

	public String toString() {
	StringBuilder builder = new StringBuilder();
	builder.append("Set{ ")
	.append("addr = ").append(addr)
	.append(", count = ").append(getCount())
	.append(", size = ").append(getSize())
	.append(", pairs = [");

	for (int i = 0; i < getCount(); ++i) {
	builder.append(getPairAt(i));
	}

	builder.append("]");
	return builder.toString();
	}
	}