webengine/osswebengine/MemoryManager/Src/heap.cpp
changeset 1 7c90e6132015
child 10 a359256acfc6
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/webengine/osswebengine/MemoryManager/Src/heap.cpp	Fri May 08 08:25:06 2009 +0300
@@ -0,0 +1,2270 @@
+/*
+* Copyright (c) 2006 Nokia Corporation and/or its subsidiary(-ies).
+* All rights reserved.
+* This component and the accompanying materials are made available
+* under the terms of the License "Eclipse Public License v1.0"
+* which accompanies this distribution, and is available
+* at the URL "http://www.eclipse.org/legal/epl-v10.html".
+*
+* Initial Contributors:
+* Nokia Corporation - initial contribution.
+*
+* Contributors:
+*
+* Description:  
+*
+*
+*/
+
+#include "common.h"
+
+#ifdef TRACE_CHUNK_USAGE
+void TraceChunkUsage(TInt aChunkHandle, TUint8* aBase, TInt aChunkSize)
+	{
+	RDebug::Print(_L("MEM: c,%d,%d,%d"), aChunkHandle, aBase, aChunkSize);
+	}
+#else
+#define TraceChunkUsage(a,b,c)
+#endif
+
+#ifdef __NEW_ALLOCATOR__
+
+#include "SymbianDLHeap.h"
+
+_LIT(KDLHeapPanicCategory, "DL Heap");
+#define	GET_PAGE_SIZE(x)			UserHal::PageSizeInBytes(x)
+#define	__CHECK_CELL(p)
+#define __POWER_OF_2(x)				((TUint32)((x)^((x)-1))>=(TUint32)(x))
+
+#define gm  (&iGlobalMallocState)
+
+void Panic(TCdtPanic aPanic)
+	{
+	User::Panic(KDLHeapPanicCategory, aPanic);
+	}
+
+#undef UEXPORT_C
+#define UEXPORT_C 
+
+UEXPORT_C RSymbianDLHeap::RSymbianDLHeap(TInt aMaxLength, TInt aAlign, TBool aSingleThread)
+// constructor for a fixed heap. Just use DL allocator
+	:iMinLength(aMaxLength), iMaxLength(aMaxLength), iOffset(0), iGrowBy(0), iChunkHandle(0),
+	iNestingLevel(0), iAllocCount(0), iFailType(ENone), iTestData(NULL), iChunkSize(aMaxLength)
+	{
+
+	// bodge so GKIServ (hudson generic low level layer) starts up ok - it uses an aAlign of 0 which panics, so if see 0 then force to 4
+	if ((TUint32)aAlign>=sizeof(TAny*) && __POWER_OF_2(iAlign))
+		{
+		iAlign = aAlign;
+		}
+	else
+		{
+		iAlign = 4;
+		}
+	iPageSize = 0;
+	iFlags = aSingleThread ? (ESingleThreaded|EFixedSize) : EFixedSize;
+
+	Init(0, 0, 0);
+	}
+
+UEXPORT_C RSymbianDLHeap::RSymbianDLHeap(TInt aChunkHandle, TInt aOffset, TInt aMinLength, TInt aMaxLength, TInt aGrowBy,
+			TInt aAlign, TBool aSingleThread)
+		: iMinLength(aMinLength), iMaxLength(aMaxLength), iOffset(aOffset), iChunkHandle(aChunkHandle), iNestingLevel(0), iAllocCount(0),
+			iAlign(aAlign),iFailType(ENone), iTestData(NULL), iChunkSize(aMinLength)
+	{
+	// TODO: Locked the page size to 4 KB - change this to pick up from the OS
+	GET_PAGE_SIZE(iPageSize);
+	__ASSERT_ALWAYS(aOffset >=0, User::Panic(KDLHeapPanicCategory, ETHeapNewBadOffset));
+	iGrowBy = _ALIGN_UP(aGrowBy, iPageSize);
+	iFlags = aSingleThread ? ESingleThreaded : 0;
+
+	// Initialise
+	// if the heap is created with aMinLength==aMaxLength then it cannot allocate slab or page memory
+	// so these sub-allocators should be disabled. Otherwise initialise with default values
+	if (aMinLength == aMaxLength)
+		Init(0, 0, 0);
+	else
+		Init(0x3fff, 16, 0x10000);	// all slabs, page {64KB}, trim {64KB}
+//		Init(0xabe, 16, iPageSize*4);	// slabs {48, 40, 32, 24, 20, 16, 12}, page {64KB}, trim {16KB}
+	}
+
+UEXPORT_C TAny* RSymbianDLHeap::operator new(TUint aSize, TAny* aBase) __NO_THROW
+	{
+	__ASSERT_ALWAYS(aSize>=sizeof(RSymbianDLHeap), HEAP_PANIC(ETHeapNewBadSize));
+	RSymbianDLHeap* h = (RSymbianDLHeap*)aBase;
+	h->iAlign = 0x80000000;	// garbage value
+	h->iBase = ((TUint8*)aBase) + aSize;
+	return aBase;
+	}
+
+void RSymbianDLHeap::Init(TInt aBitmapSlab, TInt aPagePower, size_t aTrimThreshold)
+	{
+	__ASSERT_ALWAYS((TUint32)iAlign>=sizeof(TAny*) && __POWER_OF_2(iAlign), HEAP_PANIC(ETHeapNewBadAlignment));
+
+	/*Moved code which does iunitilization */
+	iTop = (TUint8*)this + iMinLength;
+	spare_page = 0;
+	memset(&mparams,0,sizeof(mparams));
+
+	Init_Dlmalloc(iTop - iBase, 0, aTrimThreshold);
+
+	slab_init(aBitmapSlab);
+
+	/*10-1K,11-2K,12-4k,13-8K,14-16K,15-32K,16-64K*/
+	paged_init(aPagePower);
+	}
+
+UEXPORT_C RSymbianDLHeap::SCell* RSymbianDLHeap::GetAddress(const TAny* aCell) const
+//
+// As much as possible, check a cell address and backspace it
+// to point at the cell header.
+//
+	{
+
+	TLinAddr m = TLinAddr(iAlign - 1);
+	__ASSERT_ALWAYS(!(TLinAddr(aCell)&m), HEAP_PANIC(ETHeapBadCellAddress));
+
+	SCell* pC = (SCell*)(((TUint8*)aCell)-EAllocCellSize);
+	__CHECK_CELL(pC);
+
+	return pC;
+	}
+
+UEXPORT_C TInt RSymbianDLHeap::AllocLen(const TAny* aCell) const
+{
+	if (ptrdiff(aCell, this) >= 0)
+	{
+		mchunkptr m = mem2chunk(aCell);
+		return chunksize(m) - CHUNK_OVERHEAD;
+	}
+	if (lowbits(aCell, pagesize) > cellalign)
+		return header_size(slab::slabfor(aCell)->header);
+	if (lowbits(aCell, pagesize) == cellalign)
+		return *(unsigned*)(offset(aCell,-int(cellalign)))-cellalign;
+	return paged_descriptor(aCell)->size;
+}
+
+UEXPORT_C TAny* RSymbianDLHeap::Alloc(TInt aSize)
+{
+	__ASSERT_ALWAYS((TUint)aSize<(KMaxTInt/2),HEAP_PANIC(ETHeapBadAllocatedCellSize));
+
+	TAny* addr;
+
+	Lock();
+	if (aSize < slab_threshold)
+	{
+		TInt ix = sizemap[(aSize+3)>>2];
+		ASSERT(ix != 0xff);
+		addr = slab_allocate(slaballoc[ix]);
+	}else if((aSize >> page_threshold)==0)
+		{
+		addr = dlmalloc(aSize);
+		}
+	else
+		{
+		addr = paged_allocate(aSize);
+		}
+
+	Unlock();
+
+	return addr;
+}
+
+UEXPORT_C TInt RSymbianDLHeap::Compress()
+	{
+	if (iFlags & EFixedSize)
+		return 0;
+
+	Lock();
+	dlmalloc_trim(0);
+	if (spare_page)
+	{
+		unmap(spare_page, pagesize);
+		spare_page = 0;
+	}
+	Unlock();
+	return 0;
+	}
+
+UEXPORT_C void RSymbianDLHeap::Free(TAny* aPtr)
+{
+
+	Lock();
+
+	if (!aPtr)
+		;
+	else if (ptrdiff(aPtr, this) >= 0)
+		{
+		dlfree( aPtr);
+		}
+	else if (lowbits(aPtr, pagesize) <= cellalign)
+		{
+		paged_free(aPtr);
+		}
+	else
+		{
+		slab_free(aPtr);
+		}
+	Unlock();
+}
+
+
+UEXPORT_C void RSymbianDLHeap::Reset()
+	{
+	// TODO free everything
+	}
+
+UEXPORT_C TAny* RSymbianDLHeap::ReAlloc(TAny* aPtr, TInt aSize, TInt /*aMode = 0*/)
+//
+// Support aMode==0 properly: do not move the cell if the request is smaller than old size
+//
+	{
+	if(ptrdiff(aPtr,this)>=0)
+	{
+		// original cell is in DL zone
+		if((aSize>>page_threshold)==0 || aSize <= chunksize(mem2chunk(aPtr)) - CHUNK_OVERHEAD)
+			{
+			// new one is below page limit or smaller than old one (so can't be moved)
+			Lock();
+			TAny* addr = dlrealloc(aPtr,aSize);
+			Unlock();
+			return addr;
+			}
+	}
+	else if(lowbits(aPtr,pagesize)<=cellalign)
+	{
+		// original cell is either NULL or in paged zone
+		if (!aPtr)
+			return Alloc(aSize);
+
+		// either the new size is larger (in which case it will still be in paged zone)
+		// or it is smaller, but we will never move a shrinking cell so in paged zone
+		// must handle [rare] case that aSize == 0, as paged_[re]allocate() will panic
+		if (aSize == 0)
+			aSize = 1;
+		Lock();
+		TAny* addr = paged_reallocate(aPtr,aSize);
+		Unlock();
+		return addr;
+	}
+	else
+	{
+		// original cell is in slab zone
+		// return original if new one smaller
+		if(aSize <= header_size(slab::slabfor(aPtr)->header))
+			return aPtr;
+	}
+	// can't do better than allocate/copy/free
+	TAny* newp = Alloc(aSize);
+	if(newp)
+	{
+		TInt oldsize = AllocLen(aPtr);
+		memcpy(newp,aPtr,oldsize<aSize?oldsize:aSize);
+		Free(aPtr);
+	}
+	return newp;
+	}
+
+UEXPORT_C TInt RSymbianDLHeap::Available(TInt& aBiggestBlock) const
+{
+	aBiggestBlock = 0;
+	return 1000;
+	/*Need to see how to implement this*/
+	// TODO: return iHeap.Available(aBiggestBlock);
+}
+UEXPORT_C TInt RSymbianDLHeap::AllocSize(TInt& aTotalAllocSize) const
+{
+	aTotalAllocSize = 0;
+	return 0;
+}
+
+UEXPORT_C TInt RSymbianDLHeap::DebugFunction(TInt /*aFunc*/, TAny* /*a1*/, TAny* /*a2*/)
+	{
+	return 0;
+	}
+UEXPORT_C TInt RSymbianDLHeap::Extension_(TUint /* aExtensionId */, TAny*& /* a0 */, TAny* /* a1 */)
+	{
+	return KErrNotSupported;
+	}
+
+long    sysconf		(int size )
+	{
+	if (UserHal::PageSizeInBytes(size)!=KErrNone)
+		size = 0x1000;
+	return size;
+	}
+
+
+///////////////////////////////////////////////////////////////////////////////
+// imported from dla.cpp
+///////////////////////////////////////////////////////////////////////////////
+
+//#include <unistd.h>
+//#define DEBUG_REALLOC
+#ifdef DEBUG_REALLOC
+#include <e32debug.h>
+#endif
+inline int RSymbianDLHeap::init_mparams(size_t aTrimThreshold /*= DEFAULT_TRIM_THRESHOLD*/)
+{
+	if (mparams.page_size == 0)
+	{
+		size_t s;
+		mparams.mmap_threshold = DEFAULT_MMAP_THRESHOLD;
+		mparams.trim_threshold = aTrimThreshold;
+		#if MORECORE_CONTIGUOUS
+			mparams.default_mflags = USE_LOCK_BIT|USE_MMAP_BIT;
+		#else  /* MORECORE_CONTIGUOUS */
+			mparams.default_mflags = USE_LOCK_BIT|USE_MMAP_BIT|USE_NONCONTIGUOUS_BIT;
+		#endif /* MORECORE_CONTIGUOUS */
+
+			s = (size_t)0x58585858U;
+		ACQUIRE_MAGIC_INIT_LOCK(&mparams);
+		if (mparams.magic == 0) {
+		  mparams.magic = s;
+		  /* Set up lock for main malloc area */
+		  INITIAL_LOCK(&gm->mutex);
+		  gm->mflags = mparams.default_mflags;
+		}
+		RELEASE_MAGIC_INIT_LOCK(&mparams);
+
+		// DAN replaced
+		// mparams.page_size = malloc_getpagesize;
+		int temp = 0;
+		GET_PAGE_SIZE(temp);
+		mparams.page_size = temp;
+
+		mparams.granularity = ((DEFAULT_GRANULARITY != 0)?
+							   DEFAULT_GRANULARITY : mparams.page_size);
+
+		/* Sanity-check configuration:
+		   size_t must be unsigned and as wide as pointer type.
+		   ints must be at least 4 bytes.
+		   alignment must be at least 8.
+		   Alignment, min chunk size, and page size must all be powers of 2.
+		*/
+
+		if ((sizeof(size_t) != sizeof(TUint8*)) ||
+			(MAX_SIZE_T < MIN_CHUNK_SIZE)  ||
+			(sizeof(int) < 4)  ||
+			(MALLOC_ALIGNMENT < (size_t)8U) ||
+			((MALLOC_ALIGNMENT    & (MALLOC_ALIGNMENT-SIZE_T_ONE))    != 0) ||
+			((MCHUNK_SIZE         & (MCHUNK_SIZE-SIZE_T_ONE))         != 0) ||
+			((mparams.granularity & (mparams.granularity-SIZE_T_ONE)) != 0) ||
+			((mparams.page_size   & (mparams.page_size-SIZE_T_ONE))   != 0))
+		  ABORT;
+	}
+	return 0;
+}
+
+inline void RSymbianDLHeap::init_bins(mstate m) {
+  /* Establish circular links for smallbins */
+  bindex_t i;
+  for (i = 0; i < NSMALLBINS; ++i) {
+    sbinptr bin = smallbin_at(m,i);
+    bin->fd = bin->bk = bin;
+  }
+}
+/* ---------------------------- malloc support --------------------------- */
+
+/* allocate a large request from the best fitting chunk in a treebin */
+void* RSymbianDLHeap::tmalloc_large(mstate m, size_t nb) {
+  tchunkptr v = 0;
+  size_t rsize = -nb; /* Unsigned negation */
+  tchunkptr t;
+  bindex_t idx;
+  compute_tree_index(nb, idx);
+
+  if ((t = *treebin_at(m, idx)) != 0) {
+    /* Traverse tree for this bin looking for node with size == nb */
+    size_t sizebits =
+    nb <<
+    leftshift_for_tree_index(idx);
+    tchunkptr rst = 0;  /* The deepest untaken right subtree */
+    for (;;) {
+      tchunkptr rt;
+      size_t trem = chunksize(t) - nb;
+      if (trem < rsize) {
+        v = t;
+        if ((rsize = trem) == 0)
+          break;
+      }
+      rt = t->child[1];
+      t = t->child[(sizebits >> (SIZE_T_BITSIZE-SIZE_T_ONE)) & 1];
+      if (rt != 0 && rt != t)
+        rst = rt;
+      if (t == 0) {
+        t = rst; /* set t to least subtree holding sizes > nb */
+        break;
+      }
+      sizebits <<= 1;
+    }
+  }
+  if (t == 0 && v == 0) { /* set t to root of next non-empty treebin */
+    binmap_t leftbits = left_bits(idx2bit(idx)) & m->treemap;
+    if (leftbits != 0) {
+      bindex_t i;
+      binmap_t leastbit = least_bit(leftbits);
+      compute_bit2idx(leastbit, i);
+      t = *treebin_at(m, i);
+    }
+  }
+  while (t != 0) { /* find smallest of tree or subtree */
+    size_t trem = chunksize(t) - nb;
+    if (trem < rsize) {
+      rsize = trem;
+      v = t;
+    }
+    t = leftmost_child(t);
+  }
+  /*  If dv is a better fit, return 0 so malloc will use it */
+  if (v != 0 && rsize < (size_t)(m->dvsize - nb)) {
+    if (RTCHECK(ok_address(m, v))) { /* split */
+      mchunkptr r = chunk_plus_offset(v, nb);
+      assert(chunksize(v) == rsize + nb);
+      if (RTCHECK(ok_next(v, r))) {
+        unlink_large_chunk(m, v);
+        if (rsize < MIN_CHUNK_SIZE)
+          set_inuse_and_pinuse(m, v, (rsize + nb));
+        else {
+          set_size_and_pinuse_of_inuse_chunk(m, v, nb);
+          set_size_and_pinuse_of_free_chunk(r, rsize);
+          insert_chunk(m, r, rsize);
+        }
+        return chunk2mem(v);
+      }
+    }
+    CORRUPTION_ERROR_ACTION(m);
+  }
+  return 0;
+}
+
+/* allocate a small request from the best fitting chunk in a treebin */
+void* RSymbianDLHeap::tmalloc_small(mstate m, size_t nb) {
+  tchunkptr t, v;
+  size_t rsize;
+  bindex_t i;
+  binmap_t leastbit = least_bit(m->treemap);
+  compute_bit2idx(leastbit, i);
+
+  v = t = *treebin_at(m, i);
+  rsize = chunksize(t) - nb;
+
+  while ((t = leftmost_child(t)) != 0) {
+    size_t trem = chunksize(t) - nb;
+    if (trem < rsize) {
+      rsize = trem;
+      v = t;
+    }
+  }
+
+  if (RTCHECK(ok_address(m, v))) {
+    mchunkptr r = chunk_plus_offset(v, nb);
+    assert(chunksize(v) == rsize + nb);
+    if (RTCHECK(ok_next(v, r))) {
+      unlink_large_chunk(m, v);
+      if (rsize < MIN_CHUNK_SIZE)
+        set_inuse_and_pinuse(m, v, (rsize + nb));
+      else {
+        set_size_and_pinuse_of_inuse_chunk(m, v, nb);
+        set_size_and_pinuse_of_free_chunk(r, rsize);
+        replace_dv(m, r, rsize);
+      }
+      return chunk2mem(v);
+    }
+  }
+  CORRUPTION_ERROR_ACTION(m);
+  return 0;
+}
+
+inline void RSymbianDLHeap::init_top(mstate m, mchunkptr p, size_t psize)
+{
+	/* Ensure alignment */
+	size_t offset = align_offset(chunk2mem(p));
+	p = (mchunkptr)((TUint8*)p + offset);
+	psize -= offset;
+	m->top = p;
+	m->topsize = psize;
+	p->head = psize | PINUSE_BIT;
+	/* set size of fake trailing chunk holding overhead space only once */
+	mchunkptr chunkPlusOff = chunk_plus_offset(p, psize);
+	chunkPlusOff->head = TOP_FOOT_SIZE;
+	m->trim_check = mparams.trim_threshold; /* reset on each update */
+}
+
+void* RSymbianDLHeap::internal_realloc(mstate m, void* oldmem, size_t bytes)
+{
+  if (bytes >= MAX_REQUEST) {
+    MALLOC_FAILURE_ACTION;
+    return 0;
+  }
+  if (!PREACTION(m)) {
+    mchunkptr oldp = mem2chunk(oldmem);
+    size_t oldsize = chunksize(oldp);
+    mchunkptr next = chunk_plus_offset(oldp, oldsize);
+    mchunkptr newp = 0;
+    void* extra = 0;
+
+    /* Try to either shrink or extend into top. Else malloc-copy-free */
+
+    if (RTCHECK(ok_address(m, oldp) && ok_cinuse(oldp) &&
+                ok_next(oldp, next) && ok_pinuse(next))) {
+      size_t nb = request2size(bytes);
+      if (is_mmapped(oldp))
+        newp = mmap_resize(m, oldp, nb);
+      else
+	  if (oldsize >= nb) { /* already big enough */
+        size_t rsize = oldsize - nb;
+        newp = oldp;
+        if (rsize >= MIN_CHUNK_SIZE) {
+          mchunkptr remainder = chunk_plus_offset(newp, nb);
+          set_inuse(m, newp, nb);
+          set_inuse(m, remainder, rsize);
+          extra = chunk2mem(remainder);
+        }
+      }
+		/*AMOD: Modified to optimized*/
+		else if (next == m->top && oldsize + m->topsize > nb)
+		{
+			/* Expand into top */
+			if(oldsize + m->topsize > nb)
+			{
+		        size_t newsize = oldsize + m->topsize;
+		        size_t newtopsize = newsize - nb;
+		        mchunkptr newtop = chunk_plus_offset(oldp, nb);
+		        set_inuse(m, oldp, nb);
+		        newtop->head = newtopsize |PINUSE_BIT;
+		        m->top = newtop;
+		        m->topsize = newtopsize;
+		        newp = oldp;
+			}
+      }
+    }
+    else {
+      USAGE_ERROR_ACTION(m, oldmem);
+      POSTACTION(m);
+      return 0;
+    }
+
+    POSTACTION(m);
+
+    if (newp != 0) {
+      if (extra != 0) {
+        internal_free(m, extra);
+      }
+      check_inuse_chunk(m, newp);
+      return chunk2mem(newp);
+    }
+    else {
+      void* newmem = internal_malloc(m, bytes);
+      if (newmem != 0) {
+        size_t oc = oldsize - overhead_for(oldp);
+        memcpy(newmem, oldmem, (oc < bytes)? oc : bytes);
+        internal_free(m, oldmem);
+      }
+      return newmem;
+    }
+  }
+  return 0;
+}
+/* ----------------------------- statistics ------------------------------ */
+mallinfo RSymbianDLHeap::internal_mallinfo(mstate m) {
+  struct mallinfo nm = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
+  TInt chunkCnt = 0;
+  if (!PREACTION(m)) {
+    check_malloc_state(m);
+    if (is_initialized(m)) {
+      size_t nfree = SIZE_T_ONE; /* top always free */
+      size_t mfree = m->topsize + TOP_FOOT_SIZE;
+      size_t sum = mfree;
+      msegmentptr s = &m->seg;
+      TInt tmp = (TUint8*)m->top - (TUint8*)s->base;
+      while (s != 0) {
+        mchunkptr q = align_as_chunk(s->base);
+        chunkCnt++;
+        while (segment_holds(s, q) &&
+               q != m->top && q->head != FENCEPOST_HEAD) {
+          size_t sz = chunksize(q);
+          sum += sz;
+          if (!cinuse(q)) {
+            mfree += sz;
+            ++nfree;
+          }
+          q = next_chunk(q);
+        }
+        s = s->next;
+      }
+      nm.arena    = sum;
+      nm.ordblks  = nfree;
+      nm.hblkhd   = m->footprint - sum;
+      nm.usmblks  = m->max_footprint;
+      nm.uordblks = m->footprint - mfree;
+      nm.fordblks = mfree;
+      nm.keepcost = m->topsize;
+      nm.cellCount= chunkCnt;/*number of chunks allocated*/
+    }
+    POSTACTION(m);
+  }
+  return nm;
+}
+
+void  RSymbianDLHeap::internal_malloc_stats(mstate m) {
+if (!PREACTION(m)) {
+  size_t maxfp = 0;
+  size_t fp = 0;
+  size_t used = 0;
+  check_malloc_state(m);
+  if (is_initialized(m)) {
+    msegmentptr s = &m->seg;
+    maxfp = m->max_footprint;
+    fp = m->footprint;
+    used = fp - (m->topsize + TOP_FOOT_SIZE);
+
+    while (s != 0) {
+      mchunkptr q = align_as_chunk(s->base);
+      while (segment_holds(s, q) &&
+             q != m->top && q->head != FENCEPOST_HEAD) {
+        if (!cinuse(q))
+          used -= chunksize(q);
+        q = next_chunk(q);
+      }
+      s = s->next;
+    }
+  }
+  POSTACTION(m);
+}
+}
+/* support for mallopt */
+int RSymbianDLHeap::change_mparam(int param_number, int value) {
+  size_t val = (size_t)value;
+  init_mparams(DEFAULT_TRIM_THRESHOLD);
+  switch(param_number) {
+  case M_TRIM_THRESHOLD:
+    mparams.trim_threshold = val;
+    return 1;
+  case M_GRANULARITY:
+    if (val >= mparams.page_size && ((val & (val-1)) == 0)) {
+      mparams.granularity = val;
+      return 1;
+    }
+    else
+      return 0;
+  case M_MMAP_THRESHOLD:
+    mparams.mmap_threshold = val;
+    return 1;
+  default:
+    return 0;
+  }
+}
+/* Get memory from system using MORECORE or MMAP */
+void* RSymbianDLHeap::sys_alloc(mstate m, size_t nb)
+{
+	TUint8* tbase = CMFAIL;
+	size_t tsize = 0;
+	flag_t mmap_flag = 0;
+	//init_mparams();/*No need to do init_params here*/
+	/* Directly map large chunks */
+	if (use_mmap(m) && nb >= mparams.mmap_threshold)
+	{
+		void* mem = mmap_alloc(m, nb);
+		if (mem != 0)
+			return mem;
+	}
+  /*
+    Try getting memory in any of three ways (in most-preferred to
+    least-preferred order):
+    1. A call to MORECORE that can normally contiguously extend memory.
+       (disabled if not MORECORE_CONTIGUOUS or not HAVE_MORECORE or
+       or main space is mmapped or a previous contiguous call failed)
+    2. A call to MMAP new space (disabled if not HAVE_MMAP).
+       Note that under the default settings, if MORECORE is unable to
+       fulfill a request, and HAVE_MMAP is true, then mmap is
+       used as a noncontiguous system allocator. This is a useful backup
+       strategy for systems with holes in address spaces -- in this case
+       sbrk cannot contiguously expand the heap, but mmap may be able to
+       find space.
+    3. A call to MORECORE that cannot usually contiguously extend memory.
+       (disabled if not HAVE_MORECORE)
+  */
+  /*Trying to allocate the memory*/
+	if(MORECORE_CONTIGUOUS && !use_noncontiguous(m))
+	{
+	TUint8* br = CMFAIL;
+    msegmentptr ss = (m->top == 0)? 0 : segment_holding(m, (TUint8*)m->top);
+    size_t asize = 0;
+    ACQUIRE_MORECORE_LOCK(m);
+    if (ss == 0)
+	{  /* First time through or recovery */
+		TUint8* base = (TUint8*)CALL_MORECORE(0);
+		if (base != CMFAIL)
+		{
+			asize = granularity_align(nb + TOP_FOOT_SIZE + SIZE_T_ONE);
+			/* Adjust to end on a page boundary */
+			if (!is_page_aligned(base))
+				asize += (page_align((size_t)base) - (size_t)base);
+			/* Can't call MORECORE if size is negative when treated as signed */
+			if (asize < HALF_MAX_SIZE_T &&(br = (TUint8*)(CALL_MORECORE(asize))) == base)
+			{
+				tbase = base;
+				tsize = asize;
+			}
+		}
+    }
+    else
+	{
+      /* Subtract out existing available top space from MORECORE request. */
+		asize = granularity_align(nb - m->topsize + TOP_FOOT_SIZE + SIZE_T_ONE);
+    /* Use mem here only if it did continuously extend old space */
+      if (asize < HALF_MAX_SIZE_T &&
+          (br = (TUint8*)(CALL_MORECORE(asize))) == ss->base+ss->size) {
+        tbase = br;
+        tsize = asize;
+      }
+    }
+    if (tbase == CMFAIL) {    /* Cope with partial failure */
+      if (br != CMFAIL) {    /* Try to use/extend the space we did get */
+        if (asize < HALF_MAX_SIZE_T &&
+            asize < nb + TOP_FOOT_SIZE + SIZE_T_ONE) {
+          size_t esize = granularity_align(nb + TOP_FOOT_SIZE + SIZE_T_ONE - asize);
+          if (esize < HALF_MAX_SIZE_T) {
+            TUint8* end = (TUint8*)CALL_MORECORE(esize);
+            if (end != CMFAIL)
+              asize += esize;
+            else {            /* Can't use; try to release */
+              CALL_MORECORE(-asize);
+              br = CMFAIL;
+            }
+          }
+        }
+      }
+      if (br != CMFAIL) {    /* Use the space we did get */
+        tbase = br;
+        tsize = asize;
+      }
+      else
+        disable_contiguous(m); /* Don't try contiguous path in the future */
+    }
+    RELEASE_MORECORE_LOCK(m);
+  }
+  if (HAVE_MMAP && tbase == CMFAIL) {  /* Try MMAP */
+    size_t req = nb + TOP_FOOT_SIZE + SIZE_T_ONE;
+    size_t rsize = granularity_align(req);
+    if (rsize > nb) { /* Fail if wraps around zero */
+      TUint8* mp = (TUint8*)(CALL_MMAP(rsize));
+      if (mp != CMFAIL) {
+        tbase = mp;
+        tsize = rsize;
+        mmap_flag = IS_MMAPPED_BIT;
+      }
+    }
+  }
+  if (HAVE_MORECORE && tbase == CMFAIL) { /* Try noncontiguous MORECORE */
+    size_t asize = granularity_align(nb + TOP_FOOT_SIZE + SIZE_T_ONE);
+    if (asize < HALF_MAX_SIZE_T) {
+      TUint8* br = CMFAIL;
+      TUint8* end = CMFAIL;
+      ACQUIRE_MORECORE_LOCK(m);
+      br = (TUint8*)(CALL_MORECORE(asize));
+      end = (TUint8*)(CALL_MORECORE(0));
+      RELEASE_MORECORE_LOCK(m);
+      if (br != CMFAIL && end != CMFAIL && br < end) {
+        size_t ssize = end - br;
+        if (ssize > nb + TOP_FOOT_SIZE) {
+          tbase = br;
+          tsize = ssize;
+        }
+      }
+    }
+  }
+  if (tbase != CMFAIL) {
+    if ((m->footprint += tsize) > m->max_footprint)
+      m->max_footprint = m->footprint;
+    if (!is_initialized(m)) { /* first-time initialization */
+      m->seg.base = m->least_addr = tbase;
+      m->seg.size = tsize;
+      m->seg.sflags = mmap_flag;
+      m->magic = mparams.magic;
+      init_bins(m);
+      if (is_global(m))
+        init_top(m, (mchunkptr)tbase, tsize - TOP_FOOT_SIZE);
+      else {
+        /* Offset top by embedded malloc_state */
+        mchunkptr mn = next_chunk(mem2chunk(m));
+        init_top(m, mn, (size_t)((tbase + tsize) - (TUint8*)mn) -TOP_FOOT_SIZE);
+      }
+    }else {
+      /* Try to merge with an existing segment */
+      msegmentptr sp = &m->seg;
+      while (sp != 0 && tbase != sp->base + sp->size)
+        sp = sp->next;
+      if (sp != 0 && !is_extern_segment(sp) &&
+          (sp->sflags & IS_MMAPPED_BIT) == mmap_flag &&
+          segment_holds(sp, m->top))
+    	  { /* append */
+        sp->size += tsize;
+        init_top(m, m->top, m->topsize + tsize);
+      }
+      else {
+        if (tbase < m->least_addr)
+          m->least_addr = tbase;
+        sp = &m->seg;
+        while (sp != 0 && sp->base != tbase + tsize)
+          sp = sp->next;
+        if (sp != 0 &&
+            !is_extern_segment(sp) &&
+            (sp->sflags & IS_MMAPPED_BIT) == mmap_flag) {
+          TUint8* oldbase = sp->base;
+          sp->base = tbase;
+          sp->size += tsize;
+          return prepend_alloc(m, tbase, oldbase, nb);
+        }
+        else
+          add_segment(m, tbase, tsize, mmap_flag);
+      }
+    }
+    if (nb < m->topsize) { /* Allocate from new or extended top space */
+      size_t rsize = m->topsize -= nb;
+      mchunkptr p = m->top;
+      mchunkptr r = m->top = chunk_plus_offset(p, nb);
+      r->head = rsize | PINUSE_BIT;
+      set_size_and_pinuse_of_inuse_chunk(m, p, nb);
+      check_top_chunk(m, m->top);
+      check_malloced_chunk(m, chunk2mem(p), nb);
+      return chunk2mem(p);
+    }
+  }
+  /*need to check this*/
+  //errno = -1;
+  return 0;
+}
+msegmentptr RSymbianDLHeap::segment_holding(mstate m, TUint8* addr) {
+  msegmentptr sp = &m->seg;
+  for (;;) {
+    if (addr >= sp->base && addr < sp->base + sp->size)
+      return sp;
+    if ((sp = sp->next) == 0)
+      return 0;
+  }
+}
+/* Unlink the first chunk from a smallbin */
+inline void RSymbianDLHeap::unlink_first_small_chunk(mstate M,mchunkptr B,mchunkptr P,bindex_t& I)
+{
+  mchunkptr F = P->fd;
+  assert(P != B);
+  assert(P != F);
+  assert(chunksize(P) == small_index2size(I));
+  if (B == F)
+    clear_smallmap(M, I);
+  else if (RTCHECK(ok_address(M, F))) {
+    B->fd = F;
+    F->bk = B;
+  }
+  else {
+    CORRUPTION_ERROR_ACTION(M);
+  }
+}
+/* Link a free chunk into a smallbin  */
+inline void RSymbianDLHeap::insert_small_chunk(mstate M,mchunkptr P, size_t S)
+{
+  bindex_t I  = small_index(S);
+  mchunkptr B = smallbin_at(M, I);
+  mchunkptr F = B;
+  assert(S >= MIN_CHUNK_SIZE);
+  if (!smallmap_is_marked(M, I))
+    mark_smallmap(M, I);
+  else if (RTCHECK(ok_address(M, B->fd)))
+    F = B->fd;
+  else {
+    CORRUPTION_ERROR_ACTION(M);
+  }
+  B->fd = P;
+  F->bk = P;
+  P->fd = F;
+  P->bk = B;
+}
+
+
+inline void RSymbianDLHeap::insert_chunk(mstate M,mchunkptr P,size_t S)
+{
+	if (is_small(S))
+		insert_small_chunk(M, P, S);
+	else{
+		tchunkptr TP = (tchunkptr)(P); insert_large_chunk(M, TP, S);
+	 }
+}
+
+inline void RSymbianDLHeap::unlink_large_chunk(mstate M,tchunkptr X)
+{
+  tchunkptr XP = X->parent;
+  tchunkptr R;
+  if (X->bk != X) {
+    tchunkptr F = X->fd;
+    R = X->bk;
+    if (RTCHECK(ok_address(M, F))) {
+      F->bk = R;
+      R->fd = F;
+    }
+    else {
+      CORRUPTION_ERROR_ACTION(M);
+    }
+  }
+  else {
+    tchunkptr* RP;
+    if (((R = *(RP = &(X->child[1]))) != 0) ||
+        ((R = *(RP = &(X->child[0]))) != 0)) {
+      tchunkptr* CP;
+      while ((*(CP = &(R->child[1])) != 0) ||
+             (*(CP = &(R->child[0])) != 0)) {
+        R = *(RP = CP);
+      }
+      if (RTCHECK(ok_address(M, RP)))
+        *RP = 0;
+      else {
+        CORRUPTION_ERROR_ACTION(M);
+      }
+    }
+  }
+  if (XP != 0) {
+    tbinptr* H = treebin_at(M, X->index);
+    if (X == *H) {
+      if ((*H = R) == 0)
+        clear_treemap(M, X->index);
+    }
+    else if (RTCHECK(ok_address(M, XP))) {
+      if (XP->child[0] == X)
+        XP->child[0] = R;
+      else
+        XP->child[1] = R;
+    }
+    else
+      CORRUPTION_ERROR_ACTION(M);
+    if (R != 0) {
+      if (RTCHECK(ok_address(M, R))) {
+        tchunkptr C0, C1;
+        R->parent = XP;
+        if ((C0 = X->child[0]) != 0) {
+          if (RTCHECK(ok_address(M, C0))) {
+            R->child[0] = C0;
+            C0->parent = R;
+          }
+          else
+            CORRUPTION_ERROR_ACTION(M);
+        }
+        if ((C1 = X->child[1]) != 0) {
+          if (RTCHECK(ok_address(M, C1))) {
+            R->child[1] = C1;
+            C1->parent = R;
+          }
+          else
+            CORRUPTION_ERROR_ACTION(M);
+        }
+      }
+      else
+        CORRUPTION_ERROR_ACTION(M);
+    }
+  }
+}
+
+/* Unlink a chunk from a smallbin  */
+inline void RSymbianDLHeap::unlink_small_chunk(mstate M, mchunkptr P,size_t S)
+{
+  mchunkptr F = P->fd;
+  mchunkptr B = P->bk;
+  bindex_t I = small_index(S);
+  assert(P != B);
+  assert(P != F);
+  assert(chunksize(P) == small_index2size(I));
+  if (F == B)
+    clear_smallmap(M, I);
+  else if (RTCHECK((F == smallbin_at(M,I) || ok_address(M, F)) &&
+                   (B == smallbin_at(M,I) || ok_address(M, B)))) {
+    F->bk = B;
+    B->fd = F;
+  }
+  else {
+    CORRUPTION_ERROR_ACTION(M);
+  }
+}
+
+inline void RSymbianDLHeap::unlink_chunk(mstate M, mchunkptr P, size_t S)
+{
+  if (is_small(S))
+	unlink_small_chunk(M, P, S);
+  else
+  {
+	  tchunkptr TP = (tchunkptr)(P); unlink_large_chunk(M, TP);
+  }
+}
+
+inline void RSymbianDLHeap::compute_tree_index(size_t S, bindex_t& I)
+{
+  size_t X = S >> TREEBIN_SHIFT;
+  if (X == 0)
+    I = 0;
+  else if (X > 0xFFFF)
+    I = NTREEBINS-1;
+  else {
+    unsigned int Y = (unsigned int)X;
+    unsigned int N = ((Y - 0x100) >> 16) & 8;
+    unsigned int K = (((Y <<= N) - 0x1000) >> 16) & 4;
+    N += K;
+    N += K = (((Y <<= K) - 0x4000) >> 16) & 2;
+    K = 14 - N + ((Y <<= K) >> 15);
+    I = (K << 1) + ((S >> (K + (TREEBIN_SHIFT-1)) & 1));
+  }
+}
+
+/* ------------------------- Operations on trees ------------------------- */
+
+/* Insert chunk into tree */
+inline void RSymbianDLHeap::insert_large_chunk(mstate M,tchunkptr X,size_t S)
+{
+  tbinptr* H;
+  bindex_t I;
+  compute_tree_index(S, I);
+  H = treebin_at(M, I);
+  X->index = I;
+  X->child[0] = X->child[1] = 0;
+  if (!treemap_is_marked(M, I)) {
+    mark_treemap(M, I);
+    *H = X;
+    X->parent = (tchunkptr)H;
+    X->fd = X->bk = X;
+  }
+  else {
+    tchunkptr T = *H;
+    size_t K = S << leftshift_for_tree_index(I);
+    for (;;) {
+      if (chunksize(T) != S) {
+        tchunkptr* C = &(T->child[(K >> (SIZE_T_BITSIZE-SIZE_T_ONE)) & 1]);
+        K <<= 1;
+        if (*C != 0)
+          T = *C;
+        else if (RTCHECK(ok_address(M, C))) {
+          *C = X;
+          X->parent = T;
+          X->fd = X->bk = X;
+          break;
+        }
+        else {
+          CORRUPTION_ERROR_ACTION(M);
+          break;
+        }
+      }
+      else {
+        tchunkptr F = T->fd;
+        if (RTCHECK(ok_address(M, T) && ok_address(M, F))) {
+          T->fd = F->bk = X;
+          X->fd = F;
+          X->bk = T;
+          X->parent = 0;
+          break;
+        }
+        else {
+          CORRUPTION_ERROR_ACTION(M);
+          break;
+        }
+      }
+    }
+  }
+}
+
+/*
+  Unlink steps:
+
+  1. If x is a chained node, unlink it from its same-sized fd/bk links
+     and choose its bk node as its replacement.
+  2. If x was the last node of its size, but not a leaf node, it must
+     be replaced with a leaf node (not merely one with an open left or
+     right), to make sure that lefts and rights of descendents
+     correspond properly to bit masks.  We use the rightmost descendent
+     of x.  We could use any other leaf, but this is easy to locate and
+     tends to counteract removal of leftmosts elsewhere, and so keeps
+     paths shorter than minimally guaranteed.  This doesn't loop much
+     because on average a node in a tree is near the bottom.
+  3. If x is the base of a chain (i.e., has parent links) relink
+     x's parent and children to x's replacement (or null if none).
+*/
+
+/* Replace dv node, binning the old one */
+/* Used only when dvsize known to be small */
+inline void RSymbianDLHeap::replace_dv(mstate M, mchunkptr P, size_t S)
+{
+  size_t DVS = M->dvsize;
+  if (DVS != 0) {
+    mchunkptr DV = M->dv;
+    assert(is_small(DVS));
+    insert_small_chunk(M, DV, DVS);
+  }
+  M->dvsize = S;
+  M->dv = P;
+}
+
+inline void RSymbianDLHeap::compute_bit2idx(binmap_t X,bindex_t& I)
+{
+	unsigned int Y = X - 1;
+	unsigned int K = Y >> (16-4) & 16;
+	unsigned int N = K;        Y >>= K;
+	N += K = Y >> (8-3) &  8;  Y >>= K;
+	N += K = Y >> (4-2) &  4;  Y >>= K;
+	N += K = Y >> (2-1) &  2;  Y >>= K;
+	N += K = Y >> (1-0) &  1;  Y >>= K;
+	I = (bindex_t)(N + Y);
+}
+
+void RSymbianDLHeap::add_segment(mstate m, TUint8* tbase, size_t tsize, flag_t mmapped) {
+  /* Determine locations and sizes of segment, fenceposts, old top */
+  TUint8* old_top = (TUint8*)m->top;
+  msegmentptr oldsp = segment_holding(m, old_top);
+  TUint8* old_end = oldsp->base + oldsp->size;
+  size_t ssize = pad_request(sizeof(struct malloc_segment));
+  TUint8* rawsp = old_end - (ssize + FOUR_SIZE_T_SIZES + CHUNK_ALIGN_MASK);
+  size_t offset = align_offset(chunk2mem(rawsp));
+  TUint8* asp = rawsp + offset;
+  TUint8* csp = (asp < (old_top + MIN_CHUNK_SIZE))? old_top : asp;
+  mchunkptr sp = (mchunkptr)csp;
+  msegmentptr ss = (msegmentptr)(chunk2mem(sp));
+  mchunkptr tnext = chunk_plus_offset(sp, ssize);
+  mchunkptr p = tnext;
+  int nfences = 0;
+
+  /* reset top to new space */
+  init_top(m, (mchunkptr)tbase, tsize - TOP_FOOT_SIZE);
+
+  /* Set up segment record */
+  assert(is_aligned(ss));
+  set_size_and_pinuse_of_inuse_chunk(m, sp, ssize);
+  *ss = m->seg; /* Push current record */
+  m->seg.base = tbase;
+  m->seg.size = tsize;
+  m->seg.sflags = mmapped;
+  m->seg.next = ss;
+
+  /* Insert trailing fenceposts */
+  for (;;) {
+    mchunkptr nextp = chunk_plus_offset(p, SIZE_T_SIZE);
+    p->head = FENCEPOST_HEAD;
+    ++nfences;
+    if ((TUint8*)(&(nextp->head)) < old_end)
+      p = nextp;
+    else
+      break;
+  }
+  assert(nfences >= 2);
+
+  /* Insert the rest of old top into a bin as an ordinary free chunk */
+  if (csp != old_top) {
+    mchunkptr q = (mchunkptr)old_top;
+    size_t psize = csp - old_top;
+    mchunkptr tn = chunk_plus_offset(q, psize);
+    set_free_with_pinuse(q, psize, tn);
+    insert_chunk(m, q, psize);
+  }
+
+  check_top_chunk(m, m->top);
+}
+
+
+void* RSymbianDLHeap::prepend_alloc(mstate m, TUint8* newbase, TUint8* oldbase,
+                           size_t nb) {
+  mchunkptr p = align_as_chunk(newbase);
+  mchunkptr oldfirst = align_as_chunk(oldbase);
+  size_t psize = (TUint8*)oldfirst - (TUint8*)p;
+  mchunkptr q = chunk_plus_offset(p, nb);
+  size_t qsize = psize - nb;
+  set_size_and_pinuse_of_inuse_chunk(m, p, nb);
+
+  assert((TUint8*)oldfirst > (TUint8*)q);
+  assert(pinuse(oldfirst));
+  assert(qsize >= MIN_CHUNK_SIZE);
+
+  /* consolidate remainder with first chunk of old base */
+  if (oldfirst == m->top) {
+    size_t tsize = m->topsize += qsize;
+    m->top = q;
+    q->head = tsize | PINUSE_BIT;
+    check_top_chunk(m, q);
+  }
+  else if (oldfirst == m->dv) {
+    size_t dsize = m->dvsize += qsize;
+    m->dv = q;
+    set_size_and_pinuse_of_free_chunk(q, dsize);
+  }
+  else {
+    if (!cinuse(oldfirst)) {
+      size_t nsize = chunksize(oldfirst);
+      unlink_chunk(m, oldfirst, nsize);
+      oldfirst = chunk_plus_offset(oldfirst, nsize);
+      qsize += nsize;
+    }
+    set_free_with_pinuse(q, qsize, oldfirst);
+    insert_chunk(m, q, qsize);
+    check_free_chunk(m, q);
+  }
+
+  check_malloced_chunk(m, chunk2mem(p), nb);
+  return chunk2mem(p);
+}
+
+void* RSymbianDLHeap::mmap_alloc(mstate m, size_t nb) {
+  size_t mmsize = granularity_align(nb + SIX_SIZE_T_SIZES + CHUNK_ALIGN_MASK);
+  if (mmsize > nb) {     /* Check for wrap around 0 */
+    TUint8* mm = (TUint8*)(DIRECT_MMAP(mmsize));
+    if (mm != CMFAIL) {
+      size_t offset = align_offset(chunk2mem(mm));
+      size_t psize = mmsize - offset - MMAP_FOOT_PAD;
+      mchunkptr p = (mchunkptr)(mm + offset);
+      p->prev_foot = offset | IS_MMAPPED_BIT;
+      (p)->head = (psize|CINUSE_BIT);
+      mark_inuse_foot(m, p, psize);
+      chunk_plus_offset(p, psize)->head = FENCEPOST_HEAD;
+      chunk_plus_offset(p, psize+SIZE_T_SIZE)->head = 0;
+
+      if (mm < m->least_addr)
+        m->least_addr = mm;
+      if ((m->footprint += mmsize) > m->max_footprint)
+        m->max_footprint = m->footprint;
+      assert(is_aligned(chunk2mem(p)));
+      check_mmapped_chunk(m, p);
+      return chunk2mem(p);
+    }
+  }
+  return 0;
+}
+
+	int RSymbianDLHeap::sys_trim(mstate m, size_t pad)
+	{
+	  size_t released = 0;
+	  if (pad < MAX_REQUEST && is_initialized(m)) {
+	    pad += TOP_FOOT_SIZE; /* ensure enough room for segment overhead */
+
+	    if (m->topsize > pad) {
+	      /* Shrink top space in granularity-size units, keeping at least one */
+	      size_t unit = mparams.granularity;
+				size_t extra = ((m->topsize - pad + (unit - SIZE_T_ONE)) / unit - SIZE_T_ONE) * unit;
+	      msegmentptr sp = segment_holding(m, (TUint8*)m->top);
+
+	      if (!is_extern_segment(sp)) {
+	        if (is_mmapped_segment(sp)) {
+	          if (HAVE_MMAP &&
+	              sp->size >= extra &&
+	              !has_segment_link(m, sp)) { /* can't shrink if pinned */
+	            size_t newsize = sp->size - extra;
+	            /* Prefer mremap, fall back to munmap */
+	            if ((CALL_MREMAP(sp->base, sp->size, newsize, 0) != MFAIL) ||
+	                (CALL_MUNMAP(sp->base + newsize, extra) == 0)) {
+	              released = extra;
+	            }
+	          }
+	        }
+	        else if (HAVE_MORECORE) {
+	          if (extra >= HALF_MAX_SIZE_T) /* Avoid wrapping negative */
+	            extra = (HALF_MAX_SIZE_T) + SIZE_T_ONE - unit;
+	          ACQUIRE_MORECORE_LOCK(m);
+	          {
+	            /* Make sure end of memory is where we last set it. */
+	            TUint8* old_br = (TUint8*)(CALL_MORECORE(0));
+	            if (old_br == sp->base + sp->size) {
+	              TUint8* rel_br = (TUint8*)(CALL_MORECORE(-extra));
+	              TUint8* new_br = (TUint8*)(CALL_MORECORE(0));
+	              if (rel_br != CMFAIL && new_br < old_br)
+	                released = old_br - new_br;
+	            }
+	          }
+	          RELEASE_MORECORE_LOCK(m);
+	        }
+	      }
+
+	      if (released != 0) {
+	        sp->size -= released;
+	        m->footprint -= released;
+	        init_top(m, m->top, m->topsize - released);
+	        check_top_chunk(m, m->top);
+	      }
+	    }
+
+	    /* Unmap any unused mmapped segments */
+	    if (HAVE_MMAP)
+	      released += release_unused_segments(m);
+
+	    /* On failure, disable autotrim to avoid repeated failed future calls */
+	    if (released == 0)
+	      m->trim_check = MAX_SIZE_T;
+	  }
+
+	  return (released != 0)? 1 : 0;
+	}
+
+	inline int RSymbianDLHeap::has_segment_link(mstate m, msegmentptr ss)
+	{
+	  msegmentptr sp = &m->seg;
+	  for (;;) {
+	    if ((TUint8*)sp >= ss->base && (TUint8*)sp < ss->base + ss->size)
+	      return 1;
+	    if ((sp = sp->next) == 0)
+	      return 0;
+	  }
+	}
+
+	/* Unmap and unlink any mmapped segments that don't contain used chunks */
+	size_t RSymbianDLHeap::release_unused_segments(mstate m)
+	{
+	  size_t released = 0;
+	  msegmentptr pred = &m->seg;
+	  msegmentptr sp = pred->next;
+	  while (sp != 0) {
+	    TUint8* base = sp->base;
+	    size_t size = sp->size;
+	    msegmentptr next = sp->next;
+	    if (is_mmapped_segment(sp) && !is_extern_segment(sp)) {
+	      mchunkptr p = align_as_chunk(base);
+	      size_t psize = chunksize(p);
+	      /* Can unmap if first chunk holds entire segment and not pinned */
+	      if (!cinuse(p) && (TUint8*)p + psize >= base + size - TOP_FOOT_SIZE) {
+	        tchunkptr tp = (tchunkptr)p;
+	        assert(segment_holds(sp, (TUint8*)sp));
+	        if (p == m->dv) {
+	          m->dv = 0;
+	          m->dvsize = 0;
+	        }
+	        else {
+	          unlink_large_chunk(m, tp);
+	        }
+	        if (CALL_MUNMAP(base, size) == 0) {
+	          released += size;
+	          m->footprint -= size;
+	          /* unlink obsoleted record */
+	          sp = pred;
+	          sp->next = next;
+	        }
+	        else { /* back out if cannot unmap */
+	          insert_large_chunk(m, tp, psize);
+	        }
+	      }
+	    }
+	    pred = sp;
+	    sp = next;
+	  }/*End of while*/
+	  return released;
+	}
+	/* Realloc using mmap */
+	inline	mchunkptr RSymbianDLHeap::mmap_resize(mstate m, mchunkptr oldp, size_t nb)
+	{
+	  size_t oldsize = chunksize(oldp);
+	  if (is_small(nb)) /* Can't shrink mmap regions below small size */
+	    return 0;
+	  /* Keep old chunk if big enough but not too big */
+	  if (oldsize >= nb + SIZE_T_SIZE &&
+	      (oldsize - nb) <= (mparams.granularity << 1))
+	    return oldp;
+	  else {
+	    size_t offset = oldp->prev_foot & ~IS_MMAPPED_BIT;
+	    size_t oldmmsize = oldsize + offset + MMAP_FOOT_PAD;
+	    size_t newmmsize = granularity_align(nb + SIX_SIZE_T_SIZES +
+	                                         CHUNK_ALIGN_MASK);
+	    TUint8* cp = (TUint8*)CALL_MREMAP((char*)oldp - offset,
+	                                  oldmmsize, newmmsize, 1);
+	    if (cp != CMFAIL) {
+	      mchunkptr newp = (mchunkptr)(cp + offset);
+	      size_t psize = newmmsize - offset - MMAP_FOOT_PAD;
+	      newp->head = (psize|CINUSE_BIT);
+	      mark_inuse_foot(m, newp, psize);
+	      chunk_plus_offset(newp, psize)->head = FENCEPOST_HEAD;
+	      chunk_plus_offset(newp, psize+SIZE_T_SIZE)->head = 0;
+
+	      if (cp < m->least_addr)
+	        m->least_addr = cp;
+	      if ((m->footprint += newmmsize - oldmmsize) > m->max_footprint)
+	        m->max_footprint = m->footprint;
+	      check_mmapped_chunk(m, newp);
+	      return newp;
+	    }
+	  }
+	  return 0;
+	}
+
+
+void RSymbianDLHeap::Init_Dlmalloc(size_t capacity, int locked, size_t aTrimThreshold)
+	{
+		memset(gm,0,sizeof(malloc_state));
+		init_mparams(aTrimThreshold); /* Ensure pagesize etc initialized */
+		// The maximum amount that can be allocated can be calculated as:-
+		// 2^sizeof(size_t) - sizeof(malloc_state) - TOP_FOOT_SIZE - page size (all accordingly padded)
+		// If the capacity exceeds this, no allocation will be done.
+		gm->seg.base = gm->least_addr = iBase;
+		gm->seg.size = capacity;
+		gm->seg.sflags = !IS_MMAPPED_BIT;
+		set_lock(gm, locked);
+		gm->magic = mparams.magic;
+		init_bins(gm);
+		init_top(gm, (mchunkptr)iBase, capacity - TOP_FOOT_SIZE);
+	}
+
+void* RSymbianDLHeap::dlmalloc(size_t bytes) {
+  /*
+     Basic algorithm:
+     If a small request (< 256 bytes minus per-chunk overhead):
+       1. If one exists, use a remainderless chunk in associated smallbin.
+          (Remainderless means that there are too few excess bytes to
+          represent as a chunk.)
+       2. If it is big enough, use the dv chunk, which is normally the
+          chunk adjacent to the one used for the most recent small request.
+       3. If one exists, split the smallest available chunk in a bin,
+          saving remainder in dv.
+       4. If it is big enough, use the top chunk.
+       5. If available, get memory from system and use it
+     Otherwise, for a large request:
+       1. Find the smallest available binned chunk that fits, and use it
+          if it is better fitting than dv chunk, splitting if necessary.
+       2. If better fitting than any binned chunk, use the dv chunk.
+       3. If it is big enough, use the top chunk.
+       4. If request size >= mmap threshold, try to directly mmap this chunk.
+       5. If available, get memory from system and use it
+
+     The ugly goto's here ensure that postaction occurs along all paths.
+  */
+  if (!PREACTION(gm)) {
+    void* mem;
+    size_t nb;
+    if (bytes <= MAX_SMALL_REQUEST) {
+      bindex_t idx;
+      binmap_t smallbits;
+      nb = (bytes < MIN_REQUEST)? MIN_CHUNK_SIZE : pad_request(bytes);
+      idx = small_index(nb);
+      smallbits = gm->smallmap >> idx;
+
+      if ((smallbits & 0x3U) != 0) { /* Remainderless fit to a smallbin. */
+        mchunkptr b, p;
+        idx += ~smallbits & 1;       /* Uses next bin if idx empty */
+        b = smallbin_at(gm, idx);
+        p = b->fd;
+        assert(chunksize(p) == small_index2size(idx));
+        unlink_first_small_chunk(gm, b, p, idx);
+        set_inuse_and_pinuse(gm, p, small_index2size(idx));
+        mem = chunk2mem(p);
+        check_malloced_chunk(gm, mem, nb);
+        goto postaction;
+      }
+
+      else if (nb > gm->dvsize) {
+        if (smallbits != 0) { /* Use chunk in next nonempty smallbin */
+          mchunkptr b, p, r;
+          size_t rsize;
+          bindex_t i;
+          binmap_t leftbits = (smallbits << idx) & left_bits(idx2bit(idx));
+          binmap_t leastbit = least_bit(leftbits);
+          compute_bit2idx(leastbit, i);
+          b = smallbin_at(gm, i);
+          p = b->fd;
+          assert(chunksize(p) == small_index2size(i));
+          unlink_first_small_chunk(gm, b, p, i);
+          rsize = small_index2size(i) - nb;
+          /* Fit here cannot be remainderless if 4byte sizes */
+          if (SIZE_T_SIZE != 4 && rsize < MIN_CHUNK_SIZE)
+            set_inuse_and_pinuse(gm, p, small_index2size(i));
+          else {
+            set_size_and_pinuse_of_inuse_chunk(gm, p, nb);
+            r = chunk_plus_offset(p, nb);
+            set_size_and_pinuse_of_free_chunk(r, rsize);
+            replace_dv(gm, r, rsize);
+          }
+          mem = chunk2mem(p);
+          check_malloced_chunk(gm, mem, nb);
+          goto postaction;
+        }
+
+        else if (gm->treemap != 0 && (mem = tmalloc_small(gm, nb)) != 0) {
+          check_malloced_chunk(gm, mem, nb);
+          goto postaction;
+        }
+      }
+    }
+    else if (bytes >= MAX_REQUEST)
+      nb = MAX_SIZE_T; /* Too big to allocate. Force failure (in sys alloc) */
+    else {
+      nb = pad_request(bytes);
+      if (gm->treemap != 0 && (mem = tmalloc_large(gm, nb)) != 0) {
+        check_malloced_chunk(gm, mem, nb);
+        goto postaction;
+      }
+    }
+
+    if (nb <= gm->dvsize) {
+      size_t rsize = gm->dvsize - nb;
+      mchunkptr p = gm->dv;
+      if (rsize >= MIN_CHUNK_SIZE) { /* split dv */
+        mchunkptr r = gm->dv = chunk_plus_offset(p, nb);
+        gm->dvsize = rsize;
+        set_size_and_pinuse_of_free_chunk(r, rsize);
+        set_size_and_pinuse_of_inuse_chunk(gm, p, nb);
+      }
+      else { /* exhaust dv */
+        size_t dvs = gm->dvsize;
+        gm->dvsize = 0;
+        gm->dv = 0;
+        set_inuse_and_pinuse(gm, p, dvs);
+      }
+      mem = chunk2mem(p);
+      check_malloced_chunk(gm, mem, nb);
+      goto postaction;
+    }
+
+    else if (nb < gm->topsize) { /* Split top */
+      size_t rsize = gm->topsize -= nb;
+      mchunkptr p = gm->top;
+      mchunkptr r = gm->top = chunk_plus_offset(p, nb);
+      r->head = rsize | PINUSE_BIT;
+      set_size_and_pinuse_of_inuse_chunk(gm, p, nb);
+      mem = chunk2mem(p);
+      check_top_chunk(gm, gm->top);
+      check_malloced_chunk(gm, mem, nb);
+      goto postaction;
+    }
+
+    mem = sys_alloc(gm, nb);
+
+  postaction:
+    POSTACTION(gm);
+    return mem;
+  }
+
+  return 0;
+}
+
+void RSymbianDLHeap::dlfree(void* mem) {
+  /*
+     Consolidate freed chunks with preceeding or succeeding bordering
+     free chunks, if they exist, and then place in a bin.  Intermixed
+     with special cases for top, dv, mmapped chunks, and usage errors.
+  */
+
+	if (mem != 0)
+	{
+		mchunkptr p  = mem2chunk(mem);
+#if FOOTERS
+		mstate fm = get_mstate_for(p);
+		if (!ok_magic(fm))
+		{
+			USAGE_ERROR_ACTION(fm, p);
+			return;
+		}
+#else /* FOOTERS */
+#define fm gm
+#endif /* FOOTERS */
+
+		if (!PREACTION(fm))
+		{
+			check_inuse_chunk(fm, p);
+			if (RTCHECK(ok_address(fm, p) && ok_cinuse(p)))
+			{
+				size_t psize = chunksize(p);
+				mchunkptr next = chunk_plus_offset(p, psize);
+				if (!pinuse(p))
+				{
+					size_t prevsize = p->prev_foot;
+					if ((prevsize & IS_MMAPPED_BIT) != 0)
+					{
+						prevsize &= ~IS_MMAPPED_BIT;
+						psize += prevsize + MMAP_FOOT_PAD;
+						/*TInt tmp = TOP_FOOT_SIZE;
+						TUint8* top = (TUint8*)fm->top + fm->topsize + 40;
+						if((top == (TUint8*)p)&& fm->topsize > 4096)
+						{
+							fm->topsize += psize;
+							msegmentptr sp = segment_holding(fm, (TUint8*)fm->top);
+							sp->size+=psize;
+							if (should_trim(fm, fm->topsize))
+								sys_trim(fm, 0);
+ 							goto postaction;
+						}
+						else*/
+						{
+							if (CALL_MUNMAP((char*)p - prevsize, psize) == 0)
+								fm->footprint -= psize;
+							goto postaction;
+						}
+					}
+					else
+					{
+						mchunkptr prev = chunk_minus_offset(p, prevsize);
+						psize += prevsize;
+						p = prev;
+						if (RTCHECK(ok_address(fm, prev)))
+						{ /* consolidate backward */
+							if (p != fm->dv)
+							{
+								unlink_chunk(fm, p, prevsize);
+							}
+							else if ((next->head & INUSE_BITS) == INUSE_BITS)
+							{
+								fm->dvsize = psize;
+								set_free_with_pinuse(p, psize, next);
+								goto postaction;
+							}
+						}
+						else
+							goto erroraction;
+					}
+				}
+
+				if (RTCHECK(ok_next(p, next) && ok_pinuse(next)))
+				{
+					if (!cinuse(next))
+					{  /* consolidate forward */
+						if (next == fm->top)
+						{
+							size_t tsize = fm->topsize += psize;
+							fm->top = p;
+							p->head = tsize | PINUSE_BIT;
+							if (p == fm->dv)
+							{
+								fm->dv = 0;
+								fm->dvsize = 0;
+							}
+							if (should_trim(fm, tsize))
+								sys_trim(fm, 0);
+							goto postaction;
+						}
+						else if (next == fm->dv)
+						{
+							size_t dsize = fm->dvsize += psize;
+							fm->dv = p;
+							set_size_and_pinuse_of_free_chunk(p, dsize);
+							goto postaction;
+						}
+						else
+						{
+							size_t nsize = chunksize(next);
+							psize += nsize;
+							unlink_chunk(fm, next, nsize);
+							set_size_and_pinuse_of_free_chunk(p, psize);
+							if (p == fm->dv)
+							{
+								fm->dvsize = psize;
+								goto postaction;
+							}
+						}
+					}
+					else
+						set_free_with_pinuse(p, psize, next);
+					insert_chunk(fm, p, psize);
+					check_free_chunk(fm, p);
+					goto postaction;
+				}
+			}
+erroraction:
+    	USAGE_ERROR_ACTION(fm, p);
+postaction:
+    	POSTACTION(fm);
+		}
+	}
+#if !FOOTERS
+#undef fm
+#endif /* FOOTERS */
+}
+
+void* RSymbianDLHeap::dlrealloc(void* oldmem, size_t bytes) {
+  if (oldmem == 0)
+    return dlmalloc(bytes);
+#ifdef REALLOC_ZERO_BYTES_FREES
+  if (bytes == 0) {
+    dlfree(oldmem);
+    return 0;
+  }
+#endif /* REALLOC_ZERO_BYTES_FREES */
+  else {
+#if ! FOOTERS
+    mstate m = gm;
+#else /* FOOTERS */
+    mstate m = get_mstate_for(mem2chunk(oldmem));
+    if (!ok_magic(m)) {
+      USAGE_ERROR_ACTION(m, oldmem);
+      return 0;
+    }
+#endif /* FOOTERS */
+    return internal_realloc(m, oldmem, bytes);
+  }
+}
+
+
+int RSymbianDLHeap::dlmalloc_trim(size_t pad) {
+  int result = 0;
+  if (!PREACTION(gm)) {
+    result = sys_trim(gm, pad);
+    POSTACTION(gm);
+  }
+  return result;
+}
+
+size_t RSymbianDLHeap::dlmalloc_footprint(void) {
+  return gm->footprint;
+}
+
+size_t RSymbianDLHeap::dlmalloc_max_footprint(void) {
+  return gm->max_footprint;
+}
+
+#if !NO_MALLINFO
+struct mallinfo RSymbianDLHeap::dlmallinfo(void) {
+  return internal_mallinfo(gm);
+}
+#endif /* NO_MALLINFO */
+
+void RSymbianDLHeap::dlmalloc_stats() {
+  internal_malloc_stats(gm);
+}
+
+int RSymbianDLHeap::dlmallopt(int param_number, int value) {
+  return change_mparam(param_number, value);
+}
+
+//inline slab* slab::slabfor(void* p)
+slab* slab::slabfor( const void* p)
+{
+return (slab*)(floor(p, slabsize));
+}
+
+
+void RSymbianDLHeap::tree_remove(slab* s)
+{
+	slab** r = s->parent;
+	slab* c1 = s->child1;
+	slab* c2 = s->child2;
+	for (;;)
+	{
+		if (!c2)
+		{
+			*r = c1;
+			if (c1)
+				c1->parent = r;
+			return;
+		}
+		if (!c1)
+		{
+			*r = c2;
+			c2->parent = r;
+			return;
+		}
+		if (c1 > c2)
+		{
+			slab* c3 = c1;
+			c1 = c2;
+			c2 = c3;
+		}
+		slab* newc2 = c1->child2;
+		*r = c1;
+		c1->parent = r;
+		c1->child2 = c2;
+		c2->parent = &c1->child2;
+		s = c1;
+		c1 = s->child1;
+		c2 = newc2;
+		r = &s->child1;
+	}
+}	
+void RSymbianDLHeap::tree_insert(slab* s,slab** r)
+	{
+		slab* n = *r;
+		for (;;)
+		{
+			if (!n)
+			{	// tree empty
+				*r = s;
+				s->parent = r;
+				s->child1 = s->child2 = 0;
+				break;
+			}
+			if (s < n)
+			{	// insert between parent and n
+				*r = s;
+				s->parent = r;
+				s->child1 = n;
+				s->child2 = 0;
+				n->parent = &s->child1;
+				break;
+			}
+			slab* c1 = n->child1;
+			slab* c2 = n->child2;
+			if ((c1 - 1) > (c2 - 1))
+			{
+				r = &n->child1;
+				n = c1;
+			}
+			else
+			{
+				r = &n->child2;
+				n = c2;
+			}
+		}
+	}
+void* RSymbianDLHeap::allocnewslab(slabset& allocator)
+//
+// Acquire and initialise a new slab, returning a cell from the slab
+// The strategy is:
+// 1. Use the lowest address free slab, if available. This is done by using the lowest slab
+//    in the page at the root of the partial_page heap (which is address ordered). If the
+//    is now fully used, remove it from the partial_page heap.
+// 2. Allocate a new page for slabs if no empty slabs are available
+//
+{
+	page* p = page::pagefor(partial_page);
+	if (!p)
+		return allocnewpage(allocator);
+
+	unsigned h = p->slabs[0].header;
+	unsigned pagemap = header_pagemap(h);
+	ASSERT(&p->slabs[hibit(pagemap)] == partial_page);
+
+	unsigned slabix = lowbit(pagemap);
+	p->slabs[0].header = h &~ (0x100<<slabix);
+	if (!(pagemap &~ (1<<slabix)))
+	{
+		tree_remove(partial_page);	// last free slab in page
+	}
+	return allocator.initslab(&p->slabs[slabix]);
+}
+
+/**Defination of this functionis not there in proto code***/
+#if 0
+void RSymbianDLHeap::partial_insert(slab* s)
+	{
+		// slab has had first cell freed and needs to be linked back into partial tree
+		slabset& ss = slaballoc[sizemap[s->clz]];
+
+		ASSERT(s->used == slabfull);
+		s->used = ss.fulluse - s->clz;		// full-1 loading
+		tree_insert(s,&ss.partial);
+		checktree(ss.partial);
+	}
+/**Defination of this functionis not there in proto code***/
+#endif
+
+void* RSymbianDLHeap::allocnewpage(slabset& allocator)
+//
+// Acquire and initialise a new page, returning a cell from a new slab
+// The partial_page tree is empty (otherwise we'd have used a slab from there)
+// The partial_page link is put in the highest addressed slab in the page, and the
+// lowest addressed slab is used to fulfill the allocation request
+//
+{
+	page* p	 = spare_page;
+	if (p)
+		spare_page = 0;
+	else
+	{
+		p = static_cast<page*>(map(0,pagesize));
+		if (!p)
+			return 0;
+	}
+	
+	ASSERT(p == floor(p,pagesize));
+	p->slabs[0].header = ((1<<3) + (1<<2) + (1<<1))<<8;		// set pagemap
+	p->slabs[3].parent = &partial_page;
+	p->slabs[3].child1 = p->slabs[3].child2 = 0;
+	partial_page = &p->slabs[3];
+	return allocator.initslab(&p->slabs[0]);
+}
+
+void RSymbianDLHeap::freepage(page* p)
+//
+// Release an unused page to the OS
+// A single page is cached for reuse to reduce thrashing
+// the OS allocator.
+//
+{
+	ASSERT(ceiling(p,pagesize) == p);
+	if (!spare_page)
+	{
+		spare_page = p;
+		return;
+	}
+	unmap(p,pagesize);
+}
+
+void RSymbianDLHeap::freeslab(slab* s)
+//
+// Release an empty slab to the slab manager
+// The strategy is:
+// 1. The page containing the slab is checked to see the state of the other slabs in the page by
+//    inspecting the pagemap field in the header of the first slab in the page.
+// 2. The pagemap is updated to indicate the new unused slab
+// 3. If this is the only unused slab in the page then the slab header is used to add the page to
+//    the partial_page tree/heap
+// 4. If all the slabs in the page are now unused the page is release back to the OS
+// 5. If this slab has a higher address than the one currently used to track this page in
+//    the partial_page heap, the linkage is moved to the new unused slab
+//
+{
+	tree_remove(s);
+	checktree(*s->parent);
+	ASSERT(header_usedm4(s->header) == header_size(s->header)-4);
+	CHECK(s->header |= 0xFF00000);			// illegal value for debug purposes
+	page* p = page::pagefor(s);
+	unsigned h = p->slabs[0].header;
+	int slabix = s - &p->slabs[0];
+	unsigned pagemap = header_pagemap(h);
+	p->slabs[0].header = h | (0x100<<slabix);
+	if (pagemap == 0)
+	{	// page was full before, use this slab as link in empty heap
+		tree_insert(s, &partial_page);
+	}
+	else
+	{	// find the current empty-link slab
+		slab* sl = &p->slabs[hibit(pagemap)];
+		pagemap ^= (1<<slabix);
+		if (pagemap == 0xf)
+		{	// page is now empty so recycle page to os
+			tree_remove(sl);
+			freepage(p);
+			return;
+		}
+		// ensure the free list link is in highest address slab in page
+		if (s > sl)
+		{	// replace current link with new one. Address-order tree so position stays the same
+			slab** r = sl->parent;
+			slab* c1 = sl->child1;
+			slab* c2 = sl->child2;
+			s->parent = r;
+			s->child1 = c1;
+			s->child2 = c2;
+			*r = s;
+			if (c1)
+				c1->parent = &s->child1;
+			if (c2)
+				c2->parent = &s->child2;
+		}
+		CHECK(if (s < sl) s=sl);
+	}
+	ASSERT(header_pagemap(p->slabs[0].header) != 0);
+	ASSERT(hibit(header_pagemap(p->slabs[0].header)) == unsigned(s - &p->slabs[0]));
+}
+
+void RSymbianDLHeap::slab_init(unsigned slabbitmap)
+{
+	ASSERT((slabbitmap & ~okbits) == 0);
+	ASSERT(maxslabsize <= 60);
+
+	slab_threshold=0;
+	partial_page = 0;
+	unsigned char ix = 0xff;
+	unsigned bit = 1<<((maxslabsize>>2)-1);
+	for (int sz = maxslabsize; sz >= 0; sz -= 4, bit >>= 1)
+	{
+		if (slabbitmap & bit)
+		{
+			if (++ix == 0)
+				slab_threshold=sz+1;
+			slabset& c = slaballoc[ix];
+			c.size = sz;
+			c.partial = 0;
+		}
+		sizemap[sz>>2] = ix;
+	}
+}
+
+void* RSymbianDLHeap::slab_allocate(slabset& ss)
+//
+// Allocate a cell from the given slabset
+// Strategy:
+// 1. Take the partially full slab at the top of the heap (lowest address).
+// 2. If there is no such slab, allocate from a new slab
+// 3. If the slab has a non-empty freelist, pop the cell from the front of the list and update the slab
+// 4. Otherwise, if the slab is not full, return the cell at the end of the currently used region of
+//    the slab, updating the slab
+// 5. Otherwise, release the slab from the partial tree/heap, marking it as 'floating' and go back to
+//    step 1
+//
+{
+	for (;;)
+	{
+		slab *s = ss.partial;
+		if (!s)
+			break;
+		unsigned h = s->header;
+		unsigned free = h & 0xff;		// extract free cell positiong
+		if (free)
+		{
+			ASSERT(((free<<2)-sizeof(slabhdr))%header_size(h) == 0);
+			void* p = offset(s,free<<2);
+			free = *(unsigned char*)p;	// get next pos in free list
+			h += (h&0x3C000)<<6;		// update usedm4
+			h &= ~0xff;
+			h |= free;					// update freelist
+			s->header = h;
+			ASSERT(header_free(h) == 0 || ((header_free(h)<<2)-sizeof(slabhdr))%header_size(h) == 0);
+			ASSERT(header_usedm4(h) <= 0x3F8u);
+			ASSERT((header_usedm4(h)+4)%header_size(h) == 0);
+			return p;
+		}
+		unsigned h2 = h + ((h&0x3C000)<<6);
+		if (h2 < 0xfc00000)
+		{
+			ASSERT((header_usedm4(h2)+4)%header_size(h2) == 0);
+			s->header = h2;
+			return offset(s,(h>>18) + sizeof(unsigned) + sizeof(slabhdr));
+		}
+		h |= 0x80000000;				// mark the slab as full-floating
+		s->header = h;
+		tree_remove(s);
+		checktree(ss.partial);
+		// go back and try the next slab...
+	}
+	// no partial slabs found, so allocate from a new slab
+	return allocnewslab(ss);
+}
+void RSymbianDLHeap::slab_free(void* p)
+//
+// Free a cell from the slab allocator
+// Strategy:
+// 1. Find the containing slab (round down to nearest 1KB boundary)
+// 2. Push the cell into the slab's freelist, and update the slab usage count
+// 3. If this is the last allocated cell, free the slab to the main slab manager
+// 4. If the slab was full-floating then insert the slab in it's respective partial tree
+//
+{
+	ASSERT(lowbits(p,3)==0);
+	slab* s = slab::slabfor(p);
+
+	unsigned pos = lowbits(p, slabsize);
+	unsigned h = s->header;
+	ASSERT(header_usedm4(h) != 0x3fC);		// slab is empty already
+	ASSERT((pos-sizeof(slabhdr))%header_size(h) == 0);
+	*(unsigned char*)p = (unsigned char)h;
+	h &= ~0xFF;
+	h |= (pos>>2);
+	unsigned size = h & 0x3C000;
+	if (int(h) >= 0)
+	{
+		h -= size<<6;
+		if (int(h)>=0)
+		{
+			s->header = h;
+			return;
+		}
+		freeslab(s);
+		return;
+	}
+	h -= size<<6;
+	h &= ~0x80000000;
+	s->header = h;
+	slabset& ss = slaballoc[sizemap[size>>14]];
+	tree_insert(s,&ss.partial);
+	checktree(ss.partial);
+}
+
+void* slabset::initslab(slab* s)
+//
+// initialise an empty slab for this allocator and return the fist cell
+// pre-condition: the slabset has no partial slabs for allocation
+//
+{
+	ASSERT(partial==0);
+	unsigned h = s->header & 0xF00;	// preserve pagemap only
+	h |= (size<<12);					// set size
+	h |= (size-4)<<18;					// set usedminus4 to one object minus 4
+	s->header = h;
+	partial = s;
+	s->parent = &partial;
+	s->child1 = s->child2 = 0;
+	return offset(s,sizeof(slabhdr));
+}
+
+TAny* RSymbianDLHeap::SetBrk(TInt32 aDelta)
+{
+	if (iFlags & EFixedSize)
+		return MFAIL;
+
+	if (aDelta < 0)
+		{
+		unmap(offset(iTop, aDelta), -aDelta);
+		}
+	else if (aDelta > 0)
+		{
+		if (!map(iTop, aDelta))
+			return MFAIL;
+		}
+	void * p =iTop;
+	iTop = offset(iTop, aDelta);
+	
+	return p;
+}
+
+void* RSymbianDLHeap::map(void* p,unsigned sz)
+//
+// allocate pages in the chunk
+// if p is NULL, find an allocate the required number of pages (which must lie in the lower half)
+// otherwise commit the pages specified
+//
+{
+ASSERT(p == floor(p, pagesize));
+ASSERT(sz == ceiling(sz, pagesize));
+ASSERT(sz > 0);
+
+	if (iChunkSize + sz > iMaxLength)
+		return 0;
+
+	RChunk chunk;
+	chunk.SetHandle(iChunkHandle);
+	if (p)
+	{
+		TInt r = chunk.Commit(iOffset + ptrdiff(p, this),sz);
+		if (r < 0)
+			return 0;
+		ASSERT(p = offset(this, r - iOffset));
+		iChunkSize += sz;	
+		return p;
+	}
+
+	TInt r = chunk.Allocate(sz);
+	if (r < 0)
+		return 0;
+	if (r > iOffset)
+	{
+		// can't allow page allocations in DL zone
+		chunk.Decommit(r, sz);
+		return 0;
+	}
+	iChunkSize += sz;
+	
+	TraceChunkUsage(iChunkHandle, iBase, iChunkSize);
+	
+	return offset(this, r - iOffset);
+}
+
+void* RSymbianDLHeap::remap(void* p,unsigned oldsz,unsigned sz)
+{
+	if (oldsz > sz)
+		{	// shrink
+		unmap(offset(p,sz), oldsz-sz);
+		}
+	else if (oldsz < sz)
+		{	// grow, try and do this in place first
+		if (!map(offset(p, oldsz), sz-oldsz))
+			{
+			// need to allocate-copy-free
+			void* newp = map(0, sz);
+			memcpy(newp, p, oldsz);
+			unmap(p,oldsz);
+			return newp;
+			}
+		}
+	return p;
+}
+
+void RSymbianDLHeap::unmap(void* p,unsigned sz)
+{
+	ASSERT(p == floor(p, pagesize));
+	ASSERT(sz == ceiling(sz, pagesize));
+	ASSERT(sz > 0);
+
+	RChunk chunk;
+	chunk.SetHandle(iChunkHandle);
+	TInt r = chunk.Decommit(ptrdiff(p, offset(this,-iOffset)), sz);
+	//TInt offset = (TUint8*)p-(TUint8*)chunk.Base();
+	//TInt r = chunk.Decommit(offset,sz);
+
+	ASSERT(r >= 0);
+	iChunkSize -= sz;
+	
+	TraceChunkUsage(iChunkHandle, iBase, iChunkSize);
+}
+
+void RSymbianDLHeap::paged_init(unsigned pagepower)
+	{
+		if (pagepower == 0)
+			pagepower = 31;
+		else if (pagepower < minpagepower)
+			pagepower = minpagepower;
+		page_threshold = pagepower;
+		for (int i=0;i<npagecells;++i)
+		{
+			pagelist[i].page = 0;
+			pagelist[i].size = 0;
+		}
+	}
+
+void* RSymbianDLHeap::paged_allocate(unsigned size)
+{
+	unsigned nbytes = ceiling(size, pagesize);
+	if (nbytes < size + cellalign)
+	{	// not enough extra space for header and alignment, try and use cell list
+		for (pagecell *c = pagelist,*e = c + npagecells;c < e;++c)
+			if (c->page == 0)
+			{
+				void* p = map(0, nbytes);
+				if (!p)
+					return 0;
+				c->page = p;
+				c->size = nbytes;
+				return p;
+			}
+	}
+	// use a cell header
+	nbytes = ceiling(size + cellalign, pagesize);
+	void* p = map(0, nbytes);
+	if (!p)
+		return 0;
+	*static_cast<unsigned*>(p) = nbytes;
+	return offset(p, cellalign);
+}
+
+void* RSymbianDLHeap::paged_reallocate(void* p, unsigned size)
+{
+	if (lowbits(p, pagesize) == 0)
+	{	// continue using descriptor
+		pagecell* c = paged_descriptor(p);
+		unsigned nbytes = ceiling(size, pagesize);
+		void* newp = remap(p, c->size, nbytes);
+		if (!newp)
+			return 0;
+		c->page = newp;
+		c->size = nbytes;
+		return newp;
+	}
+	else
+	{	// use a cell header
+		ASSERT(lowbits(p,pagesize) == cellalign);
+		p = offset(p,-int(cellalign));
+		unsigned nbytes = ceiling(size + cellalign, pagesize);
+		unsigned obytes = *static_cast<unsigned*>(p);
+		void* newp = remap(p, obytes, nbytes);
+		if (!newp)
+			return 0;
+		*static_cast<unsigned*>(newp) = nbytes;
+		return offset(newp, cellalign);
+	}
+}
+
+void RSymbianDLHeap::paged_free(void* p)
+{
+	if (lowbits(p,pagesize) == 0)
+	{	// check pagelist
+		pagecell* c = paged_descriptor(p);
+		unmap(p, c->size);
+		c->page = 0;
+		c->size = 0;
+	}
+	else
+	{	// check page header
+		unsigned* page = static_cast<unsigned*>(offset(p,-int(cellalign)));
+		unsigned size = *page;
+		unmap(page,size);
+	}
+}
+
+pagecell* RSymbianDLHeap::paged_descriptor(const void* p) const
+{
+	ASSERT(lowbits(p,pagesize) == 0);
+	// Double casting to keep the compiler happy. Seems to think we can trying to
+	// change a non-const member (pagelist) in a const function
+	pagecell* c = (pagecell*)((void*)pagelist);
+	pagecell* e = c + npagecells;
+	for (;;)
+	{
+		ASSERT(c!=e);
+		if (c->page == p)
+			return c;
+		++c;
+	}
+}
+
+#endif