internal virtual void StopTheWorld()
{
#if SINGULARITY
//DebugStub.WriteLine("~~~~~ StopTheWorld()");
Monitoring.Log(Monitoring.Provider.GC,
(ushort)GarbageCollectorEvent.StartStopTheWorld);
#if SINGULARITY_KERNEL
TimeSpan ticks = SystemClock.KernelUpTime;
#elif SINGULARITY_PROCESS
TimeSpan ticks = ProcessService.GetUpTime();
#endif
#endif
VTable.Assert(Thread.GetCurrentThreadIndex() ==
collectorThreadIndex);
BaseCollector.AllThreadRendezvous(collectorThreadIndex);
#if SINGULARITY
#if SINGULARITY_KERNEL
ticks = SystemClock.KernelUpTime - ticks;
#elif SINGULARITY_PROCESS
ticks = ProcessService.GetUpTime() - ticks;
#endif
Monitoring.Log(Monitoring.Provider.GC,
(ushort)GarbageCollectorEvent.EndStopTheWorld);
#endif
}
private UIntPtr FreshAlloc(UIntPtr bytes, uint alignment,
Thread currentThread)
{
#if SINGULARITY_KERNEL
Kernel.Waypoint(702);
#endif
this.Truncate();
UIntPtr paddedBytes =
PageTable.PagePad(bytes + alignment - UIntPtr.Size);
BaseCollector.IncrementNewBytesSinceGC(paddedBytes);
UIntPtr pages = PageTable.PageCount(paddedBytes);
bool fCleanPages = CLEAR_POOL_PAGES();
// We may eventually want to ask for specific pages
// between asking if any pages are reusable and asking the
// OS for any possible page.
UIntPtr startPage =
PageManager.EnsurePages(currentThread, pages, this.pageType,
ref fCleanPages);
UIntPtr startAddr = PageTable.PageAddr(startPage);
UIntPtr limitAddr = PageTable.PageAddr(startPage + pages);
startAddr = Allocator.AlignedAllocationPtr(startAddr, limitAddr,
alignment);
this.allocNew = startAddr;
this.allocPtr = startAddr + bytes;
if (fCleanPages)
{
this.zeroedLimit = limitAddr;
}
else
{
Util.MemClear(startAddr, bytes);
this.zeroedLimit = this.allocPtr;
}
this.reserveLimit = limitAddr;
UIntPtr resultAddr = startAddr + PreHeader.Size;
InteriorPtrTable.SetFirst(resultAddr);
#if !SINGULARITY || SEMISPACE_COLLECTOR || ADAPTIVE_COPYING_COLLECTOR || SLIDING_COLLECTOR
if (GC.remsetType == RemSetType.Cards)
{
UIntPtr nextPageAddr = startAddr + PageTable.PageSize;
VTable.Assert(resultAddr < nextPageAddr);
if (this.allocPtr > nextPageAddr)
{
#if DONT_RECORD_OBJALLOC_IN_OFFSETTABLE
#else
OffsetTable.SetLast(resultAddr);
#endif
}
}
#endif
#if SINGULARITY_KERNEL
Kernel.Waypoint(703);
#endif
return(resultAddr);
}
internal virtual void ResumeTheWorld()
{
VTable.Assert(Thread.GetCurrentThreadIndex() ==
collectorThreadIndex);
BaseCollector.AllThreadRelease(collectorThreadIndex);
}
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
}
private UIntPtr ExtendAlloc(UIntPtr bytes, uint alignment,
Thread currentThread)
{
if (this.reserveLimit == UIntPtr.Zero)
{
return(UIntPtr.Zero);
}
#if SINGULARITY_KERNEL
Kernel.Waypoint(700);
#endif
UIntPtr neededBytes =
bytes + // Bytes required for object +
alignment - UIntPtr.Size - // worst case alignment overhead +
(this.reserveLimit - this.allocPtr); // bytes already available
UIntPtr paddedNeed = PageTable.PagePad(neededBytes);
UIntPtr pageCount = PageTable.PageCount(paddedNeed);
UIntPtr startPage = PageTable.Page(this.reserveLimit);
bool fCleanPages = CLEAR_POOL_PAGES();
bool gotPages =
PageManager.TryReserveUnusedPages(currentThread, startPage,
pageCount, this.pageType,
ref fCleanPages);
if (!gotPages)
{
// We can't indiscriminately ask for more memory if we have
// unused pages already available.
return(UIntPtr.Zero);
}
if (this.reserveLimit == UIntPtr.Zero)
{
// A collection occurred, so there is no region to extend
PageManager.ReleaseUnusedPages(startPage, pageCount,
fCleanPages);
return(UIntPtr.Zero);
}
BaseCollector.IncrementNewBytesSinceGC(paddedNeed);
this.allocNew = this.reserveLimit;
// Pad alignment space if necessary. NB: a prior call to
// AllocateFast may have started generating alignment tokens,
// but we may need to finish the job here if the residual space
// was insufficient for a multi-word alignment.
UIntPtr oldReserveLimit = this.reserveLimit;
this.reserveLimit += paddedNeed;
this.allocPtr =
Allocator.AlignedAllocationPtr(this.allocPtr,
this.reserveLimit,
alignment);
if (this.zeroedLimit < this.allocPtr)
{
this.zeroedLimit = this.allocPtr;
}
UIntPtr objectAddr = this.allocPtr + PreHeader.Size;
this.allocPtr += bytes;
if (fCleanPages)
{
if (this.zeroedLimit < oldReserveLimit)
{
Util.MemClear(this.zeroedLimit,
oldReserveLimit - this.zeroedLimit);
}
this.zeroedLimit = this.reserveLimit;
}
else
{
Util.MemClear(this.zeroedLimit,
this.allocPtr - this.zeroedLimit);
this.zeroedLimit = this.allocPtr;
}
VTable.Assert(this.allocPtr <= this.zeroedLimit);
VTable.Assert(PageTable.PageAligned(this.reserveLimit));
if (objectAddr >= oldReserveLimit)
{
// Object is first on new page
InteriorPtrTable.SetFirst(objectAddr);
}
else if (objectAddr + bytes < this.reserveLimit)
{
// The object does not end on new limit
// N.B. The next object may not be allocated at exactly
// (objectAddr + bytes) due to alignment considerations. It
// also might not ever be allocated. These cases are handled
// by InteriorPtrTable.First skipping over alignment tokens
// and callers of First watching out for unused space tokens.
InteriorPtrTable.SetFirst(objectAddr + bytes);
}
// We know an object is located as the last one in a page
// when it extends through the page to the next.
// Otherwise, it is totally before or below the page, and
// we are not sure whether it is the last object or not.
// So record only such an object for the last card in that
// page. Many objects may have been omitted due to
// this coarse-grain recording. But we should be able
// to incrementally update the offset table and find them.
// I believe this is a better choice than simply recording
// any object to the offset table, because most objects
// may just die and need not to record.
#if !SINGULARITY || SEMISPACE_COLLECTOR || ADAPTIVE_COPYING_COLLECTOR || SLIDING_COLLECTOR
if (GC.remsetType == RemSetType.Cards)
{
if (objectAddr < oldReserveLimit &&
allocPtr + bytes > oldReserveLimit)
{
#if DONT_RECORD_OBJALLOC_IN_OFFSETTABLE
#else
OffsetTable.SetLast(objectAddr);
#endif
}
}
#endif
#if SINGULARITY_KERNEL
Kernel.Waypoint(701);
#endif
return(objectAddr);
}
