sysperfana/heapanalyser/Libraries/Engine/HeapLib/Relationships/RelationshipInspector.cs
/*
* Copyright (c) 2010 Nokia Corporation and/or its subsidiary(-ies).
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* - Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* - Neither the name of Nokia Corporation nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
* Initial Contributors:
* Nokia Corporation - initial contribution.
*
* Contributors:
*
* Description:
*
*/
using System;
using System.Collections;
using System.Collections.Generic;
using HeapLib.Cells;
using HeapLib.Array;
using HeapLib.Statistics;
using SymbianUtils.RawItems;
using SymbianUtils.TextUtilities.Readers.Types.Array;
namespace HeapLib.Relationships
{
internal class RelationshipInspector : AsyncEnumerableReader<HeapCell>
{
#region Constructors & destructor
public RelationshipInspector( HeapCellArray aEntries, HeapStatistics aStats )
: base( null )
{
iEntries = aEntries;
iStats = aStats;
}
#endregion
#region API
public void InspectLater( HeapCell aCell )
{
iDictionary.Add( aCell );
}
public void Inspect()
{
iResultCache.Clear();
base.Setup( iDictionary.Count, iDictionary.GetEnumerator() );
base.AsyncRead();
}
#endregion
#region From AsyncEnumerableReader
protected override void HandleObject( HeapCell aObject, long aIndex, long aCount )
{
CheckForCrossReferences( aObject );
}
protected override void HandleReadCompleted()
{
iResultCache.Clear();
iDictionary.Clear();
base.HandleReadCompleted();
}
#endregion
#region Internal methods
private void CheckForCrossReferences( HeapCell aCell )
{
// If we're dealing with a free cell, then set up the free cell
// linked list.
if ( aCell.Type == HeapCell.TType.EFree && aCell.HeaderRawItems.Count == 2 )
{
uint length = aCell.HeaderRawItems[ 0 ].Data;
uint address = aCell.HeaderRawItems[ 1 ].Data;
//
LocateMatch( aCell, aCell.HeaderRawItems[ 1 ], 0 );
}
// For all other cells, identify other links
foreach( RawItem rawItem in aCell )
{
uint headerOffset = HeapCell.CellHeaderSize( aCell.Type );
LocateMatch( aCell, rawItem, headerOffset );
}
}
private void LocateMatch( HeapCell aCell, RawItem aItem, uint aHeaderOffset )
{
RelationshipManager linkManager = aCell.RelationshipManager;
// Now check if this address exactly matches a heap cell
if ( iStats.WithinHeapBounds( aItem.Data ) )
{
// The address of another object within the heap
// is always the address of the object within the payload
// section of a heap cell. Therefore in order to find the
// corresponding heap cell address, we must subtract the
// heap cell header length from the starting address.
//
// In other words, the rawItem.Data value points to a payload address.
// However, our cell search function (CellByExactAddress) works in
// terms of a heap cell address. The heap cell includes [header + payload].
//
// In order to convert the object address into a heap cell address,
// we must subtract the allocated heap cell header size from the
// raw address.
uint exactMatchAddress = aItem.Data - aHeaderOffset;
HeapCell cell = iEntries.CellByExactAddress( exactMatchAddress );
if ( cell != null && cell.Address != aCell.Address )
{
linkManager.AddEmbeddedReferenceTo( aItem, cell );
}
else if ( cell == null )
{
uint partialMatchAddress = aItem.Data;
// Didn't find an exact match, but we might find that this address
// points to part way through another heap cell.
cell = Lookup( partialMatchAddress );
if ( cell != null && cell.Address != aCell.Address )
{
// It also has to point to the payload
HeapCell.TRegion region = cell.RegionForAddress( partialMatchAddress );
if ( region == HeapCell.TRegion.EPayload )
{
linkManager.AddEmbeddedReferenceTo( aItem, cell );
}
}
}
}
}
private HeapCell Lookup( uint aAddress )
{
HeapCell ret = null;
//
if ( !iResultCache.TryGetValue( aAddress, out ret ) )
{
ret = iEntries.CellByAddress( aAddress );
if ( ret != null )
{
iResultCache.Add( aAddress, ret );
}
}
//
return ret;
}
#endregion
#region Data members
private readonly HeapCellArray iEntries;
private readonly HeapStatistics iStats;
private RelationshipDictionary iDictionary = new RelationshipDictionary();
private Dictionary<uint, HeapCell> iResultCache = new Dictionary<uint, HeapCell>();
#endregion
}
}