GC fixes/improvements

- Have a real finalizer stage for destroying objects instead of mixing them
  in to the sweep stage.
- Base GC rate on a running average of the allocation rate instead of basing
  it on the amount of time taken since the last sweep started.
- More GC stats for better tweaking.

src/common/engine/stats.h

@@ -221,6 +221,11 @@ public:
 		Counter = 0;
 	}
 
+	void ResetAndClock()
+	{
+		Counter = -static_cast<int64_t>(rdtsc());
+	}
+
 	void Clock()
 	{
 		int64_t time = rdtsc();

src/common/objects/dobjgc.cpp

@@ -82,23 +82,58 @@
 ** infinity, where each step performs a full collection.) You can also
 ** change this value dynamically.
 */
-#define DEFAULT_GCMUL		200 // GC runs 'double the speed' of memory allocation
+#ifndef _DEBUG
+#define DEFAULT_GCMUL		600 // GC runs gcmul% the speed of memory allocation
+#else
+// Higher in debug builds to account for the extra time spent freeing objects
+#define DEFAULT_GCMUL		800
+#endif
 
 // Minimum step size
-#define GCSTEPSIZE		(sizeof(DObject) * 16)
+#define GCMINSTEPSIZE		(sizeof(DObject) * 16)
 
-// Maximum number of elements to sweep in a single step
+// Sweeps traverse objects in chunks of this size
-#define GCSWEEPMAX		40
+#define GCSWEEPGRANULARITY	40
 
-// Cost of sweeping one element (the size of a small object divided by
+// Cost of deleting an object
-// some adjust for the sweep speed)
+#ifndef _DEBUG
-#define GCSWEEPCOST		(sizeof(DObject) / 4)
+#define GCDELETECOST		75
+#else
+// Freeing memory is much more costly in debug builds
+#define GCDELETECOST		230
+#endif
 
-// Cost of calling of one destructor
+// Cost of destroying an object
-#define GCFINALIZECOST	100
+#define GCDESTROYCOST		15
 
 // TYPES -------------------------------------------------------------------
 
+class FAveragizer
+{
+	// Number of allocations to track
+	static inline constexpr unsigned HistorySize = 512;
+
+	size_t History[HistorySize];
+	size_t TotalAmount;
+	int TotalCount;
+	unsigned NewestPos;
+
+public:
+	FAveragizer();
+	void AddAlloc(size_t alloc);
+	size_t GetAverage();
+};
+
+struct FStepStats
+{
+	cycle_t Clock[GC::GCS_COUNT];
+	size_t BytesCovered[GC::GCS_COUNT];
+	int Count[GC::GCS_COUNT];
+
+	void Format(FString &out);
+	void Reset();
+};
+
 // EXTERNAL FUNCTION PROTOTYPES --------------------------------------------
 
 // PUBLIC FUNCTION PROTOTYPES ----------------------------------------------
@@ -114,28 +149,50 @@ static size_t CalcStepSize();
 namespace GC
 {
 size_t AllocBytes;
+size_t RunningAllocBytes;
+size_t RunningDeallocBytes;
 size_t Threshold;
 size_t Estimate;
 DObject *Gray;
 DObject *Root;
 DObject *SoftRoots;
 DObject **SweepPos;
+DObject *ToDestroy;
 uint32_t CurrentWhite = OF_White0 | OF_Fixed;
 EGCState State = GCS_Pause;
 int Pause = DEFAULT_GCPAUSE;
 int StepMul = DEFAULT_GCMUL;
-int StepCount;
+FStepStats StepStats;
-uint64_t CheckTime;
+FStepStats PrevStepStats;
 bool FinalGC;
+bool HadToDestroy;
 
 // PRIVATE DATA DEFINITIONS ------------------------------------------------
 
-static int LastCollectTime;		// Time last time collector finished
+static FAveragizer AllocHistory;// Tracks allocation rate over time
-static size_t LastCollectAlloc;	// Memory allocation when collector finished
+static cycle_t GCTime;			// Track time spent in GC
-static size_t MinStepSize;		// Cover at least this much memory per step
 
 // CODE --------------------------------------------------------------------
 
+//==========================================================================
+//
+// CheckGC
+// 
+// Check if it's time to collect, and do a collection step if it is.
+// Also does some bookkeeping. Should be called fairly consistantly.
+//
+//==========================================================================
+
+void CheckGC()
+{
+	AllocHistory.AddAlloc(RunningAllocBytes);
+	RunningAllocBytes = 0;
+	if (State > GCS_Pause || AllocBytes >= Threshold)
+	{
+		Step();
+	}
+}
+
 //==========================================================================
 //
 // SetThreshold
@@ -146,7 +203,7 @@ static size_t MinStepSize;		// Cover at least this much memory per step
 
 void SetThreshold()
 {
-	Threshold = (Estimate / 100) * Pause;
+	Threshold = (std::min(Estimate, AllocBytes) / 100) * Pause;
 }
 
 //==========================================================================
@@ -170,55 +227,72 @@ size_t PropagateMark()
 
 //==========================================================================
 //
-// SweepList
+// SweepObjects
 //
-// Runs a limited sweep on a list, returning the position in the list just
+// Runs a limited sweep on the object list, returning the number of bytes
-// after the last object swept.
+// swept.
 //
 //==========================================================================
 
-static DObject **SweepList(DObject **p, size_t count, size_t *finalize_count)
+static size_t SweepObjects(size_t count)
 {
 	DObject *curr;
 	int deadmask = OtherWhite();
-	size_t finalized = 0;
+	size_t swept = 0;
 
-	while ((curr = *p) != NULL && count-- > 0)
+	while ((curr = *SweepPos) != nullptr && count-- > 0)
 	{
+		swept += curr->GetClass()->Size;
 		if ((curr->ObjectFlags ^ OF_WhiteBits) & deadmask)	// not dead?
 		{
 			assert(!curr->IsDead() || (curr->ObjectFlags & OF_Fixed));
 			curr->MakeWhite();	// make it white (for next cycle)
-			p = &curr->ObjNext;
+			SweepPos = &curr->ObjNext;
 		}
-		else	// must erase 'curr'
+		else
 		{
 			assert(curr->IsDead());
-			*p = curr->ObjNext;
 			if (!(curr->ObjectFlags & OF_EuthanizeMe))
-			{	// The object must be destroyed before it can be finalized.
+			{	// The object must be destroyed before it can be deleted.
-				// Note that thinkers must already have been destroyed. If they get here without
+				curr->GCNext = ToDestroy;
-				// having been destroyed first, it means they somehow became unattached from the
+				ToDestroy = curr;
-				// thinker lists. If I don't maintain the invariant that all live thinkers must
+				SweepPos = &curr->ObjNext;
-				// be in a thinker list, then I need to add write barriers for every time a
-				// thinker pointer is changed. This seems easier and perfectly reasonable, since
-				// a live thinker that isn't on a thinker list isn't much of a thinker.
-
-				// However, this can happen during deletion of the thinker list while cleaning up
-				// from a savegame error so we can't assume that any thinker that gets here is an error.
-
-				curr->Destroy();
 			}
+			else
+			{	// must erase 'curr'
+				*SweepPos = curr->ObjNext;
 				curr->ObjectFlags |= OF_Cleanup;
 				delete curr;
-			finalized++;
+				swept += GCDELETECOST;
 			}
 		}
-	if (finalize_count != NULL)
+	}
+	return swept;
+}
+
+//==========================================================================
+//
+// DestroyObjects
+//
+// Destroys up to count objects on a list linked on GCNext, returning the
+// size of objects destroyed, for updating the estimate.
+//
+//==========================================================================
+
+static size_t DestroyObjects(size_t count)
+{
+	DObject *curr;
+	size_t bytes_destroyed = 0;
+
+	while ((curr = ToDestroy) != nullptr && count-- > 0)
 	{
-		*finalize_count = finalized;
+		assert(!(curr->ObjectFlags & OF_EuthanizeMe));
+		bytes_destroyed += curr->GetClass()->Size + GCDESTROYCOST;
+		ToDestroy = curr->GCNext;
+		curr->GCNext = nullptr;
+		curr->Destroy();
 	}
-	return p;
+	return bytes_destroyed;
 }
 
 //==========================================================================
@@ -269,20 +343,14 @@ void MarkArray(DObject **obj, size_t count)
 //
 // CalcStepSize
 //
-// Decide how big a step should be based, depending on how long it took to
+// Decide how big a step should be, based on the current allocation rate.
-// allocate up to the threshold from the amount left after the previous
-// collection.
 //
 //==========================================================================
 
 static size_t CalcStepSize()
 {
-	int time_passed = int(CheckTime - LastCollectTime);
+	size_t avg = AllocHistory.GetAverage();
-	auto alloc = min(LastCollectAlloc, Estimate);
+	return std::max<size_t>(GCMINSTEPSIZE, avg * StepMul / 100);
-	size_t bytes_gained = AllocBytes > alloc ? AllocBytes - alloc : 0;
-	return (StepMul > 0 && time_passed > 0)
-		? std::max<size_t>(GCSTEPSIZE, bytes_gained / time_passed * StepMul / 100)
-		: std::numeric_limits<size_t>::max() / 2;		// no limit
 }
 
 //==========================================================================
@@ -302,15 +370,18 @@ void AddMarkerFunc(GCMarkerFunc func)
 
 static void MarkRoot()
 {
-	Gray = NULL;
+	PrevStepStats = StepStats;
+	StepStats.Reset();
+
+	Gray = nullptr;
 
 	for (auto func : markers) func();
 
 	// Mark soft roots.
-	if (SoftRoots != NULL)
+	if (SoftRoots != nullptr)
 	{
 		DObject **probe = &SoftRoots->ObjNext;
-		while (*probe != NULL)
+		while (*probe != nullptr)
 		{
 			DObject *soft = *probe;
 			probe = &soft->ObjNext;
@@ -322,7 +393,6 @@ static void MarkRoot()
 	}
 	// Time to propagate the marks.
 	State = GCS_Propagate;
-	StepCount = 0;
 }
 
 //==========================================================================
@@ -341,10 +411,21 @@ static void Atomic()
 	SweepPos = &Root;
 	State = GCS_Sweep;
 	Estimate = AllocBytes;
+}
 
-	// Now that we are about to start a sweep, establish a baseline minimum
+//==========================================================================
-	// step size for how much memory we want to sweep each CheckGC().
+//
-	MinStepSize = CalcStepSize();
+// SweepDone
+// 
+// Sets up the Destroy phase, if there are any dead objects that haven't
+// been destroyed yet, or skips to the Done state.
+//
+//==========================================================================
+
+static void SweepDone()
+{
+	HadToDestroy = ToDestroy != nullptr;
+	State = HadToDestroy ? GCS_Destroy : GCS_Done;
 }
 
 //==========================================================================
@@ -364,7 +445,7 @@ static size_t SingleStep()
 		return 0;
 
 	case GCS_Propagate:
-		if (Gray != NULL)
+		if (Gray != nullptr)
 		{
 			return PropagateMark();
 		}
@@ -375,22 +456,30 @@ static size_t SingleStep()
 		}
 
 	case GCS_Sweep: {
-		size_t old = AllocBytes;
+		RunningDeallocBytes = 0;
-		size_t finalize_count;
+		size_t swept = SweepObjects(GCSWEEPGRANULARITY);
-		SweepPos = SweepList(SweepPos, GCSWEEPMAX, &finalize_count);
+		Estimate -= RunningDeallocBytes;
-		if (*SweepPos == NULL)
+		if (*SweepPos == nullptr)
 		{ // Nothing more to sweep?
-			State = GCS_Finalize;
+			SweepDone();
 		}
-		//assert(old >= AllocBytes);
+		return swept;
-		Estimate -= max<size_t>(0, old - AllocBytes);
-		return (GCSWEEPMAX - finalize_count) * GCSWEEPCOST + finalize_count * GCFINALIZECOST;
 	  }
 
-	case GCS_Finalize:
+	case GCS_Destroy: {
+		size_t destroy_size;
+		destroy_size = DestroyObjects(GCSWEEPGRANULARITY);
+		Estimate -= destroy_size;
+		if (ToDestroy == nullptr)
+		{ // Nothing more to destroy?
+			State = GCS_Done;
+		}
+		return destroy_size;
+	  }
+
+	case GCS_Done:
 		State = GCS_Pause;		// end collection
-		LastCollectAlloc = AllocBytes;
+		SetThreshold();
-		LastCollectTime = (int)CheckTime;
 		return 0;
 
 	default:
@@ -403,21 +492,27 @@ static size_t SingleStep()
 //
 // Step
 //
-// Performs enough single steps to cover GCSTEPSIZE * StepMul% bytes of
+// Performs enough single steps to cover <StepSize> bytes of memory.
-// memory.
+// Some of those bytes might be "fake" to account for the cost of freeing
+// or destroying object.
 //
 //==========================================================================
 
 void Step()
 {
-	// We recalculate a step size in case the rate of allocation went up
+	GCTime.ResetAndClock();
-	// since we started sweeping because we don't want to fall behind.
+
-	// However, we also don't want to go slower than what was decided upon
+	auto enter_state = State;
-	// when the sweep began if the rate of allocation has slowed.
+	StepStats.Count[enter_state]++;
-	size_t lim = max(CalcStepSize(), MinStepSize);
+	StepStats.Clock[enter_state].Clock();
+
+	size_t did = 0;
+	size_t lim = CalcStepSize();
+
 	do
 	{
 		size_t done = SingleStep();
+		did += done;
 		if (done < lim)
 		{
 			lim -= done;
@@ -426,17 +521,23 @@ void Step()
 		{
 			lim = 0;
 		}
+		if (State != enter_state)
+		{
+			// Finish stats on old state
+			StepStats.Clock[enter_state].Unclock();
+			StepStats.BytesCovered[enter_state] += did;
+
+			// Start stats on new state
+			did = 0;
+			enter_state = State;
+			StepStats.Clock[enter_state].Clock();
+			StepStats.Count[enter_state]++;
+		}
 	} while (lim && State != GCS_Pause);
-	if (State != GCS_Pause)
+
-	{
+	StepStats.Clock[enter_state].Unclock();
-		Threshold = AllocBytes;
+	StepStats.BytesCovered[enter_state] += did;
-	}
+	GCTime.Unclock();
-	else
-	{
-		assert(AllocBytes >= Estimate);
-		SetThreshold();
-	}
-	StepCount++;
 }
 
 //==========================================================================
@@ -454,20 +555,23 @@ void FullGC()
 		// Reset sweep mark to sweep all elements (returning them to white)
 		SweepPos = &Root;
 		// Reset other collector lists
-		Gray = NULL;
+		Gray = nullptr;
 		State = GCS_Sweep;
 	}
-	// Finish any pending sweep phase
+	// Finish any pending GC stages
-	while (State != GCS_Finalize)
+	while (State != GCS_Pause)
 	{
 		SingleStep();
 	}
+	// Loop until everything that can be destroyed and freed is
+	do
+	{
 		MarkRoot();
 		while (State != GCS_Pause)
 		{
 			SingleStep();
 		}
-	SetThreshold();
+	} while (HadToDestroy);
 }
 
 //==========================================================================
@@ -481,9 +585,9 @@ void FullGC()
 
 void Barrier(DObject *pointing, DObject *pointed)
 {
-	assert(pointing == NULL || (pointing->IsBlack() && !pointing->IsDead()));
+	assert(pointing == nullptr || (pointing->IsBlack() && !pointing->IsDead()));
 	assert(pointed->IsWhite() && !pointed->IsDead());
-	assert(State != GCS_Finalize && State != GCS_Pause);
+	assert(State != GCS_Destroy && State != GCS_Pause);
 	assert(!(pointed->ObjectFlags & OF_Released));	// if a released object gets here, something must be wrong.
 	if (pointed->ObjectFlags & OF_Released) return;	// don't do anything with non-GC'd objects.
 	// The invariant only needs to be maintained in the propagate state.
@@ -495,7 +599,7 @@ void Barrier(DObject *pointing, DObject *pointed)
 	}
 	// In other states, we can mark the pointing object white so this
 	// barrier won't be triggered again, saving a few cycles in the future.
-	else if (pointing != NULL)
+	else if (pointing != nullptr)
 	{
 		pointing->MakeWhite();
 	}
@@ -503,13 +607,13 @@ void Barrier(DObject *pointing, DObject *pointed)
 
 void DelSoftRootHead()
 {
-	if (SoftRoots != NULL)
+	if (SoftRoots != nullptr)
 	{
 		// Don't let the destructor print a warning message
 		SoftRoots->ObjectFlags |= OF_YesReallyDelete;
 		delete SoftRoots;
 	}
-	SoftRoots = NULL;
+	SoftRoots = nullptr;
 }
 
 //==========================================================================
@@ -526,7 +630,7 @@ void AddSoftRoot(DObject *obj)
 	DObject **probe;
 
 	// Are there any soft roots yet?
-	if (SoftRoots == NULL)
+	if (SoftRoots == nullptr)
 	{
 		// Create a new object to root the soft roots off of, and stick
 		// it at the end of the object list, so we know that anything
@@ -534,17 +638,17 @@ void AddSoftRoot(DObject *obj)
 		SoftRoots = Create<DObject>();
 		SoftRoots->ObjectFlags |= OF_Fixed;
 		probe = &Root;
-		while (*probe != NULL)
+		while (*probe != nullptr)
 		{
 			probe = &(*probe)->ObjNext;
 		}
 		Root = SoftRoots->ObjNext;
-		SoftRoots->ObjNext = NULL;
+		SoftRoots->ObjNext = nullptr;
 		*probe = SoftRoots;
 	}
 	// Mark this object as rooted and move it after the SoftRoots marker.
 	probe = &Root;
-	while (*probe != NULL && *probe != obj)
+	while (*probe != nullptr && *probe != obj)
 	{
 		probe = &(*probe)->ObjNext;
 	}
@@ -567,14 +671,14 @@ void DelSoftRoot(DObject *obj)
 {
 	DObject **probe;
 
-	if (!(obj->ObjectFlags & OF_Rooted))
+	if (obj == nullptr || !(obj->ObjectFlags & OF_Rooted))
 	{ // Not rooted, so nothing to do.
 		return;
 	}
 	obj->ObjectFlags &= ~OF_Rooted;
 	// Move object out of the soft roots part of the list.
 	probe = &SoftRoots;
-	while (*probe != NULL && *probe != obj)
+	while (*probe != nullptr && *probe != obj)
 	{
 		probe = &(*probe)->ObjNext;
 	}
@@ -588,6 +692,52 @@ void DelSoftRoot(DObject *obj)
 
 }
 
+//==========================================================================
+//
+// FAveragizer - Constructor
+//
+//==========================================================================
+
+FAveragizer::FAveragizer()
+{
+	NewestPos = 0;
+	TotalAmount = 0;
+	TotalCount = 0;
+	memset(History, 0, sizeof(History));
+}
+
+//==========================================================================
+//
+// FAveragizer :: AddAlloc
+//
+//==========================================================================
+
+void FAveragizer::AddAlloc(size_t alloc)
+{
+	NewestPos = (NewestPos + 1) & (HistorySize - 1);
+	if (TotalCount < HistorySize)
+	{
+		TotalCount++;
+	}
+	else
+	{
+		TotalAmount -= History[NewestPos];
+	}
+	History[NewestPos] = alloc;
+	TotalAmount += alloc;
+}
+
+//==========================================================================
+//
+// FAveragizer :: GetAverage
+//
+//==========================================================================
+
+size_t FAveragizer::GetAverage()
+{
+	return TotalCount != 0 ? TotalAmount / TotalCount : 0;
+}
+
 //==========================================================================
 //
 // STAT gc
@@ -602,18 +752,66 @@ ADD_STAT(gc)
 		"  Pause  ",
 		"Propagate",
 		"  Sweep  ",
-		"Finalize " };
+		" Destroy ",
+		"  Done   "
+	};
 	FString out;
-	out.Format("[%s] Alloc:%6zuK  Thresh:%6zuK  Est:%6zuK  Steps: %d  %zuK",
+	double time = GC::State != GC::GCS_Pause ? GC::GCTime.TimeMS() : 0;
+
+	GC::PrevStepStats.Format(out);
+	out << "\n";
+	GC::StepStats.Format(out);
+	out.AppendFormat("\n%.2fms [%s] Rate:%3zuK (%3zuK)  Alloc:%6zuK  Est:%6zuK  Thresh:%6zuK",
+		time,
 		StateStrings[GC::State],
+		(GC::AllocHistory.GetAverage() + 1023) >> 10,
+		(GC::CalcStepSize() + 1023) >> 10,
 		(GC::AllocBytes + 1023) >> 10,
-		(GC::Threshold + 1023) >> 10,
 		(GC::Estimate + 1023) >> 10,
-		GC::StepCount,
+		(GC::Threshold + 1023) >> 10);
-		(GC::MinStepSize + 1023) >> 10);
 	return out;
 }
 
+//==========================================================================
+//
+// FStepStats :: Reset
+//
+//==========================================================================
+
+void FStepStats::Reset()
+{
+	for (int i = 0; i < countof(Count); ++i)
+	{
+		Count[i] = 0;
+		BytesCovered[i] = 0;
+		Clock[i].Reset();
+	}
+}
+
+//==========================================================================
+//
+// FStepStats :: Format
+//
+// Appends its stats to the given FString.
+//
+//==========================================================================
+
+void FStepStats::Format(FString &out)
+{
+	// Because everything in the default green is hard to distinguish,
+	// each stage has its own color.
+	for (int i = GC::GCS_Propagate; i < GC::GCS_Done; ++i)
+	{
+		int count = Count[i];
+		double time = Clock[i].TimeMS();
+		out.AppendFormat(TEXTCOLOR_ESCAPESTR "%c[%c%6zuK %4d*%.2fms]",
+			"-NKB"[i],	/* Color codes */
+			"-PSD"[i],	/* Stage prefixes: (P)ropagate, (S)weep, (D)estroy */
+			(BytesCovered[i] + 1023) >> 10, count, count != 0 ? time / count : time);
+	}
+	out << TEXTCOLOR_GREEN;
+}
+
 //==========================================================================
 //
 // CCMD gc

src/common/objects/dobjgc.h

@@ -37,12 +37,21 @@ namespace GC
 		GCS_Pause,
 		GCS_Propagate,
 		GCS_Sweep,
-		GCS_Finalize
+		GCS_Destroy,
+		GCS_Done,
+
+		GCS_COUNT
 	};
 
 	// Number of bytes currently allocated through M_Malloc/M_Realloc.
 	extern size_t AllocBytes;
 
+	// Number of bytes allocated since last collection step.
+	extern size_t RunningAllocBytes;
+
+	// Number of bytes freed since last collection step.
+	extern size_t RunningDeallocBytes;
+
 	// Amount of memory to allocate before triggering a collection.
 	extern size_t Threshold;
 
@@ -70,18 +79,12 @@ namespace GC
 	// Is this the final collection just before exit?
 	extern bool FinalGC;
 
-	// Counts the number of times CheckGC has been called.
-	extern uint64_t CheckTime;
-
 	// Current white value for known-dead objects.
 	static inline uint32_t OtherWhite()
 	{
 		return CurrentWhite ^ OF_WhiteBits;
 	}
 
-	// Frees all objects, whether they're dead or not.
-	void FreeAll();
-
 	// Does one collection step.
 	void Step();
 
@@ -118,12 +121,7 @@ namespace GC
 	}
 
 	// Check if it's time to collect, and do a collection step if it is.
-	static inline void CheckGC()
+	void CheckGC();
-	{
-		CheckTime++;
-		if (AllocBytes >= Threshold)
-			Step();
-	}
 
 	// Forces a collection to start now.
 	static inline void StartCollection()
@@ -176,6 +174,32 @@ namespace GC
 	using GCMarkerFunc = void(*)();
 	void AddMarkerFunc(GCMarkerFunc func);
 
+	// Report an allocation to the GC
+	static inline void ReportAlloc(size_t alloc)
+	{
+		AllocBytes += alloc;
+		RunningAllocBytes += alloc;
+	}
+
+	// Report a deallocation to the GC
+	static inline void ReportDealloc(size_t dealloc)
+	{
+		AllocBytes -= dealloc;
+		RunningDeallocBytes += dealloc;
+	}
+
+	// Report a reallocation to the GC
+	static inline void ReportRealloc(size_t oldsize, size_t newsize)
+	{
+		if (oldsize < newsize)
+		{
+			ReportAlloc(newsize - oldsize);
+		}
+		else
+		{
+			ReportDealloc(oldsize - newsize);
+		}
+	}
 }
 
 // A template class to help with handling read barriers. It does not

src/common/utility/m_alloc.cpp

@@ -3,7 +3,7 @@
 ** Wrappers for the malloc family of functions that count used bytes.
 **
 **---------------------------------------------------------------------------
-** Copyright 1998-2008 Randy Heit
+** Copyright 1998-2008 Marisa Heit
 ** All rights reserved.
 **
 ** Redistribution and use in source and binary forms, with or without
@@ -45,7 +45,7 @@
 #endif
 
 #include "engineerrors.h"
-#include "dobject.h"
+#include "dobjgc.h"
 
 #ifndef _MSC_VER
 #define _NORMAL_BLOCK			0
@@ -59,25 +59,22 @@ void *M_Malloc(size_t size)
 {
 	void *block = malloc(size);
 
-	if (block == NULL)
+	if (block == nullptr)
 		I_FatalError("Could not malloc %zu bytes", size);
 
-	GC::AllocBytes += _msize(block);
+	GC::ReportAlloc(_msize(block));
 	return block;
 }
 
 void *M_Realloc(void *memblock, size_t size)
 {
-	if (memblock != NULL)
+	size_t oldsize = memblock ? _msize(memblock) : 0;
-	{
-		GC::AllocBytes -= _msize(memblock);
-	}
 	void *block = realloc(memblock, size);
-	if (block == NULL)
+	if (block == nullptr)
 	{
 		I_FatalError("Could not realloc %zu bytes", size);
 	}
-	GC::AllocBytes += _msize(block);
+	GC::ReportRealloc(oldsize, _msize(block));
 	return block;
 }
 #else
@@ -85,28 +82,25 @@ void *M_Malloc(size_t size)
 {
 	void *block = malloc(size+sizeof(size_t));
 
-	if (block == NULL)
+	if (block == nullptr)
 		I_FatalError("Could not malloc %zu bytes", size);
 
 	size_t *sizeStore = (size_t *) block;
 	*sizeStore = size;
 	block = sizeStore+1;
 
-	GC::AllocBytes += _msize(block);
+	GC::ReportAlloc(_msize(block));
 	return block;
 }
 
 void *M_Realloc(void *memblock, size_t size)
 {
-	if(memblock == NULL)
+	if (memblock == nullptr)
 		return M_Malloc(size);
 
-	if (memblock != NULL)
+	size_t oldsize = _msize(memblock);
-	{
-		GC::AllocBytes -= _msize(memblock);
-	}
 	void *block = realloc(((size_t*) memblock)-1, size+sizeof(size_t));
-	if (block == NULL)
+	if (block == nullptr)
 	{
 		I_FatalError("Could not realloc %zu bytes", size);
 	}
@@ -115,7 +109,7 @@ void *M_Realloc(void *memblock, size_t size)
 	*sizeStore = size;
 	block = sizeStore+1;
 
-	GC::AllocBytes += _msize(block);
+	GC::ReportRealloc(oldsize, _msize(block));
 	return block;
 }
 #endif
@@ -129,25 +123,22 @@ void *M_Malloc_Dbg(size_t size, const char *file, int lineno)
 {
 	void *block = _malloc_dbg(size, _NORMAL_BLOCK, file, lineno);
 
-	if (block == NULL)
+	if (block == nullptr)
 		I_FatalError("Could not malloc %zu bytes in %s, line %d", size, file, lineno);
 
-	GC::AllocBytes += _msize(block);
+	GC::ReportAlloc(_msize(block));
 	return block;
 }
 
 void *M_Realloc_Dbg(void *memblock, size_t size, const char *file, int lineno)
 {
-	if (memblock != NULL)
+	size_t oldsize = memblock ? _msize(memblock) : 0;
-	{
-		GC::AllocBytes -= _msize(memblock);
-	}
 	void *block = _realloc_dbg(memblock, size, _NORMAL_BLOCK, file, lineno);
-	if (block == NULL)
+	if (block == nullptr)
 	{
 		I_FatalError("Could not realloc %zu bytes in %s, line %d", size, file, lineno);
 	}
-	GC::AllocBytes += _msize(block);
+	GC::ReportRealloc(oldsize, _msize(block));
 	return block;
 }
 #else
@@ -155,29 +146,26 @@ void *M_Malloc_Dbg(size_t size, const char *file, int lineno)
 {
 	void *block = _malloc_dbg(size+sizeof(size_t), _NORMAL_BLOCK, file, lineno);
 
-	if (block == NULL)
+	if (block == nullptr)
 		I_FatalError("Could not malloc %zu bytes in %s, line %d", size, file, lineno);
 
 	size_t *sizeStore = (size_t *) block;
 	*sizeStore = size;
 	block = sizeStore+1;
 
-	GC::AllocBytes += _msize(block);
+	GC::ReportAlloc(_msize(block));
 	return block;
 }
 
 void *M_Realloc_Dbg(void *memblock, size_t size, const char *file, int lineno)
 {
-	if(memblock == NULL)
+	if (memblock == nullptr)
 		return M_Malloc_Dbg(size, file, lineno);
 
-	if (memblock != NULL)
+	size_t oldsize = _msize(memblock);
-	{
-		GC::AllocBytes -= _msize(memblock);
-	}
 	void *block = _realloc_dbg(((size_t*) memblock)-1, size+sizeof(size_t), _NORMAL_BLOCK, file, lineno);
 
-	if (block == NULL)
+	if (block == nullptr)
 	{
 		I_FatalError("Could not realloc %zu bytes in %s, line %d", size, file, lineno);
 	}
@@ -186,29 +174,22 @@ void *M_Realloc_Dbg(void *memblock, size_t size, const char *file, int lineno)
 	*sizeStore = size;
 	block = sizeStore+1;
 
-	GC::AllocBytes += _msize(block);
+	GC::ReportRealloc(oldsize, _msize(block));
 	return block;
 }
 #endif
 #endif
 
+void M_Free (void *block)
+{
+	if (block != nullptr)
+	{
+		GC::ReportDealloc(_msize(block));
 #if !defined(__solaris__) && !defined(__OpenBSD__) && !defined(__DragonFly__)
-void M_Free (void *block)
-{
-	if (block != NULL)
-	{
-		GC::AllocBytes -= _msize(block);
 		free(block);
-	}
-}
 #else
-void M_Free (void *block)
-{
-	if(block != NULL)
-	{
-		GC::AllocBytes -= _msize(block);
 		free(((size_t*) block)-1);
+#endif
 	}
 }
-#endif