protected static void deallocateObjects
(NonNullReferenceVisitor decrementer)
{
int startTicks = 0;
bool enableGCTiming = VTable.enableGCTiming;
if (enableGCTiming)
{
VTable.enableGCTiming = false;
startTicks = Environment.TickCount;
}
if (VTable.enableGCWatermarks)
{
MemoryAccounting.RecordHeapWatermarks();
}
// Set up a block to deallocate, if one doesn't exist.
if (beingDeallocatedBlock == null &&
delayedDeallocationList != null)
{
beingDeallocatedBlock = delayedDeallocationList;
delayedDeallocationList =
getNextLink(delayedDeallocationList);
delayedDeallocationLength--;
UIntPtr objAddr = Magic.addressOf(beingDeallocatedBlock);
VTable vtable = beingDeallocatedBlock.vtable;
initIncrementalDecrement(objAddr, vtable);
}
// Perform up to a constant number of work chunks on the
// block being deallocated. A "work chunk" is either
// decrementing up to a fixed number of references held in
// an object, decrementing up to a fixed number of slots
// if the object is an array, or reclaiming the object
// after all decrements on its internal contents are done.
for (uint workDone = 0; beingDeallocatedBlock != null &&
workDone < deallocationSpan; workDone++)
{
// Continue work on block.
UIntPtr objAddr = Magic.addressOf(beingDeallocatedBlock);
#if DEBUG
UIntPtr page = PageTable.Page(objAddr);
VTable.Assert(PageTable.IsGcPage(page),
@"PageTable.IsGcPage(page)");
#endif // DEBUG
VTable vtable = beingDeallocatedBlock.vtable;
if (incrementalDecrement(objAddr, vtable,
decrementer) != 0)
{
continue;
}
// All decrements on contained references are over.
Object obj = beingDeallocatedBlock;
VTable.Assert((obj.REF_STATE & RSMasks.refCount) == 0,
@"(obj.REF_STATE & RSMasks.refCount) == 0");
#if DEBUG
PLCLink *plcLinkAddr = GetPLCLink(obj);
VTable.Assert(plcLinkAddr == null,
@"plcLinkAddr == null");
#endif // DEBUG
SegregatedFreeList.Free(obj);
// Set up block to work on next.
beingDeallocatedBlock = delayedDeallocationList;
if (delayedDeallocationList != null)
{
delayedDeallocationList =
getNextLink(delayedDeallocationList);
delayedDeallocationLength--;
objAddr = Magic.addressOf(beingDeallocatedBlock);
vtable = beingDeallocatedBlock.vtable;
initIncrementalDecrement(objAddr, vtable);
}
}
SegregatedFreeList.RecycleGlobalPages();
SegregatedFreeList.CommitFreedData();
GC.newBytesSinceGC = UIntPtr.Zero;
if (enableGCTiming)
{
int elapsedTicks = Environment.TickCount - startTicks;
System.GC.gcTotalTime += elapsedTicks;
if (System.GC.maxPauseTime < elapsedTicks)
{
System.GC.maxPauseTime = elapsedTicks;
}
System.GC.pauseCount++;
VTable.enableGCTiming = true;
}
}
private static unsafe void processPLCList()
{
int startTicks = 0;
bool enableGCTiming = VTable.enableGCTiming;
if (enableGCTiming)
{
VTable.enableGCTiming = false;
startTicks = Environment.TickCount;
}
if (VTable.enableGCWatermarks)
{
MemoryAccounting.RecordHeapWatermarks();
}
#if DEBUG
VTable.Assert(firstPLCLink->objAddr == UIntPtr.Zero,
@"firstPLCLink->objAddr == UIntPtr.Zero");
#endif // DEBUG
// Let S be the subgraph of heap objects reachable from
// the PLC list. Decrement counts due to references in S.
for (PLCLink *link = firstPLCLink->next; link != null;
link = link->next)
{
UIntPtr objAddr = link->objAddr;
VTable.Assert(objAddr != UIntPtr.Zero,
@"objAddr != UIntPtr.Zero");
Object obj = Magic.fromAddress(objAddr);
VTable.Assert((obj.REF_STATE &
countingONFlagMask) != 0,
@"(obj.REF_STATE &
countingONFlagMask) != 0");
uint refState = obj.REF_STATE;
if ((refState & markFlagMask) == 0)
{
obj.REF_STATE = refState | markFlagMask;
internalDecrementer.Traverse(objAddr);
}
}
// Objects that now have non-zero counts are those that
// have references external to S incident on them.
// Recompute counts due to reachability from such objects.
for (PLCLink *link = firstPLCLink->next; link != null;
link = link->next)
{
UIntPtr objAddr = link->objAddr;
internalScanner.Traverse(objAddr);
}
// String together objects with reference count
// of zero for reclamation.
internalReclaimer.Initialize();
for (PLCLink *link = firstPLCLink->next; link != null;
link = link->next)
{
UIntPtr objAddr = link->objAddr;
internalReclaimer.Traverse(objAddr);
}
ulong reclaimedBytes = 0;
Object reclaimedObj = internalReclaimer.ReclaimedObjects;
while (reclaimedObj != null)
{
if (VTable.enableGCProfiling)
{
UIntPtr size = ObjectLayout.Sizeof(reclaimedObj);
reclaimedBytes += (ulong)size;
}
Object nextReclaimedObj = getNextLink(reclaimedObj);
SegregatedFreeList.Free(reclaimedObj);
reclaimedObj = nextReclaimedObj;
}
// Recycle the PLC list.
if (firstPLCLink->next != null)
{
PLCLink *lastPLCLink = firstPLCLink;
do
{
lastPLCLink = lastPLCLink->next;
} while (lastPLCLink->next != null);
lastPLCLink->next = plcListChunk;
plcListChunk = firstPLCLink->next;
firstPLCLink->next = null;
}
// Release the memory used up by work lists.
UIntPtrQueue.ReleaseStandbyPages(null);
SegregatedFreeList.RecycleGlobalPages();
SegregatedFreeList.CommitFreedData();
GC.newBytesSinceGC = UIntPtr.Zero;
if (enableGCTiming)
{
int elapsedTicks = Environment.TickCount - startTicks;
System.GC.gcTotalTime += elapsedTicks;
if (System.GC.maxPauseTime < elapsedTicks)
{
System.GC.maxPauseTime = elapsedTicks;
}
System.GC.pauseCount++;
VTable.enableGCTiming = true;
}
if (VTable.enableGCProfiling)
{
if (maxCyclicGarbage < reclaimedBytes)
{
maxCyclicGarbage = reclaimedBytes;
}
totalCyclicGarbage += reclaimedBytes;
cycleCollections++;
}
}
private void PerformCollection(int currentThreadIndex,
int generation)
{
// Clear the GCRequest bit (if necessary) before doing
// anything that could cause a state transition.
if (Transitions.HasGCRequest(currentThreadIndex))
{
Transitions.ClearGCRequest(currentThreadIndex);
}
int startTicks = 0;
bool enableGCTiming = VTable.enableGCTiming;
if (enableGCTiming || VTable.enableFinalGCTiming)
{
VTable.enableGCTiming = false;
startTicks = Environment.TickCount;
if (enableGCTiming)
{
VTable.DebugPrint("[GC start: {0} bytes]\n",
__arglist(TotalMemory));
}
}
#if SINGULARITY
Tracing.Log(Tracing.Debug, "GC start");
#endif
CollectorStatistics.Event(GCEvent.StopTheWorld);
CurrentPhase = StopTheWorldPhase.Synchronizing;
StopTheWorld();
CurrentPhase = StopTheWorldPhase.SingleThreaded;
StartGCCycle();
#if SINGULARITY
long preGcMemoryUsage = GC.GetTotalMemory(false);
#if SINGULARITY_KERNEL
#if THREAD_TIME_ACCOUNTING
TimeSpan ticks = Thread.CurrentThread.ExecutionTime;
TimeSpan ticks2 = SystemClock.KernelUpTime;
#else
TimeSpan ticks = SystemClock.KernelUpTime;
#endif
#elif SINGULARITY_PROCESS
#if THREAD_TIME_ACCOUNTING
TimeSpan ticks = ProcessService.GetThreadTime();
TimeSpan ticks2 = ProcessService.GetUpTime();
#else
TimeSpan ticks = ProcessService.GetUpTime();
#endif
#endif
#endif //singularity
#if SINGULARITY_KERNEL
bool iflag = Processor.DisableInterrupts();
// Disable interrupts on other CPU's
MpExecution.StopProcessorsForGC();
#endif
#if SINGULARITY
ulong beg = Isa.GetCycleCount();
#endif
// Preparation
GC.allocationGCInhibitCount++;
// Verify the heap before GC
if (VTable.enableGCVerify)
{
this.VerifyHeap(true);
}
// Invoke the chosen collector
#if SINGULARITY
Monitoring.Log(Monitoring.Provider.GC,
(ushort)GarbageCollectorEvent.StartCollection);
#endif
this.CollectStopped(collectorThreadIndex, generation);
#if SINGULARITY
Monitoring.Log(Monitoring.Provider.GC,
(ushort)GarbageCollectorEvent.EndCollection);
#endif
// Verify the heap after GC
if (VTable.enableGCVerify)
{
this.VerifyHeap(false);
}
if (VTable.enableGCAccounting)
{
MemoryAccounting.Report(GC.gcType);
}
// Cleanup
CollectorStatistics.Event(GCEvent.ResumeTheWorld);
GC.allocationGCInhibitCount--;
CurrentPhase = StopTheWorldPhase.Idle;
#if SINGULARITY
long postGcMemoryUsage = GC.GetTotalMemory(false);
#endif
if (enableGCTiming || VTable.enableFinalGCTiming)
{
int elapsedTicks = Environment.TickCount - startTicks;
BaseCollector.RegisterPause(elapsedTicks);
if (enableGCTiming)
{
VTable.DebugPrint("[GC end : {0} bytes, {1} ms]\n",
__arglist(TotalMemory, elapsedTicks));
VTable.enableGCTiming = true;
}
}
if (VTable.enableGCProfiling)
{
ulong totalMemory = (ulong)GC.GetTotalMemory(false);
this.RegisterHeapSize(totalMemory);
}
ResumeTheWorld();
collectorThreadIndex = -1;
#if SINGULARITY
Tracing.Log(Tracing.Debug, "GC stop");
long pagesCollected = preGcMemoryUsage - postGcMemoryUsage;
#if SINGULARITY_KERNEL
#if THREAD_TIME_ACCOUNTING
int procId = Thread.CurrentProcess.ProcessId;
ticks = Thread.CurrentThread.ExecutionTime - ticks;
ticks2 = SystemClock.KernelUpTime - ticks2;
Process.kernelProcess.SetGcPerformanceCounters(ticks, (long)pagesCollected);
#else
ticks = SystemClock.KernelUpTime - ticks;
#endif
Thread.CurrentProcess.SetGcPerformanceCounters(ticks, (long)pagesCollected);
#elif SINGULARITY_PROCESS
#if THREAD_TIME_ACCOUNTING
ushort procId = ProcessService.GetCurrentProcessId();
ticks = ProcessService.GetThreadTime() - ticks;
ticks2 = ProcessService.GetUpTime() - ticks2;
#else
ticks = ProcessService.GetUpTime() - ticks;
#endif
ProcessService.SetGcPerformanceCounters(ticks, (long)pagesCollected);
#endif
#if DEBUG
#if THREAD_TIME_ACCOUNTING
DebugStub.WriteLine("~~~~~ StopTheWorld [collected pages={0:x8}, pid={1:x3}, ms(Thread)={2:d6}, ms(System)={3:d6}, procId={4}, tid={5}]",
__arglist(pagesCollected,
PageTable.processTag >> 16,
ticks.Milliseconds,
ticks2.Milliseconds,
procId,
Thread.GetCurrentThreadIndex()
));
#endif
#endif
#endif
#if SINGULARITY
DebugStub.AddToPerfCounter(GC.perfCounter, Isa.GetCycleCount() - beg);
#endif
#if SINGULARITY_KERNEL
// Resume interrupts on other CPU's
MpExecution.ResumeProcessorsAfterGC();
Processor.RestoreInterrupts(iflag);
#endif
}