internal static void ConstructHeap()
{
PageTable.Initialize();
MemoryManager.Initialize();
#if OS_WINCE
UIntPtr heap_commit_size = new UIntPtr(1 << 16);
#elif SINGULARITY
UIntPtr heap_commit_size = new UIntPtr(1 << 16);
#else
UIntPtr heap_commit_size = new UIntPtr(1 << 20);
#endif
UIntPtr os_commit_size = MemoryManager.OperatingSystemCommitSize;
VTable.Assert(os_commit_size > UIntPtr.Zero);
VTable.Assert(heap_commit_size >= os_commit_size);
UIntPtr bootstrapSize;
if (UIntPtr.Size == 8)
{
if (gcType == GCType.ConcurrentMSCollector)
{
// increase bootstrap size so that
// the concurrent mark sweep collector will run on
// 64-bit Windows
bootstrapSize = (UIntPtr)1 << 16;
}
else
{
bootstrapSize = (UIntPtr)1 << 15;
}
}
else
{
bootstrapSize = (UIntPtr)1 << 14;
}
if (bootstrapSize < os_commit_size)
{
bootstrapSize = os_commit_size;
}
BootstrapMemory.Initialize(bootstrapSize);
StaticData.Initialize();
PageManager.Initialize(os_commit_size, heap_commit_size);
CallStack.Initialize();
}
static Delegate()
{
CriticalSection = new Mutex();
NativeDelegateTable = new NativeDelegateRecord[24][];
NativeDelegateTable[0] = new NativeDelegateRecord[FIRST_TABLE_SIZE];
FreeExtentStartIdx = 0;
FreeListStartIdx = FREE_LIST_EMPTY;
#if FALSE // Enable this code to force testing of the FreeNativeDelegateRecord fn
for (int i = 0; i < FIRST_TABLE_SIZE * 2; i++)
{
int idx = AllocateNativeDelegateRecord(CriticalSection);
VTable.Assert(idx == i);
}
for (int i = 0; i < FIRST_TABLE_SIZE * 2; i++)
{
FreeNativeDelegateRecord(i);
}
#endif
}
// Creates a new guid with all contents having value of 0
private Guid(bool blank)
{
// Must initialize value class members even if the native
// function reinitializes them. Compiler appeasement.
_a = 0;
_b = 0;
_c = 0;
_d = 0;
_e = 0;
_f = 0;
_g = 0;
_h = 0;
_i = 0;
_j = 0;
_k = 0;
if (!blank)
{
// Create a new Guid...
Counter++;
_k = (byte)(Counter & 0xff);
_j = (byte)(Counter >> 8);
VTable.DebugPrint("CreateGuid.Guid(" + Counter + ")\n");
}
}
internal static Object AllocateObject(VTable vtable)
{
return(AllocateObject(vtable, Thread.CurrentThread));
}
public static void Assert(bool truth, string statement)
{
VTable.Assert(truth, statement);
}
extern private static Array AllocateVector(VTable vtable, int numElements);
public override Type GetElementType()
{
VTable element = this.classVtable.arrayElementClass;
return((element != null) ? element.vtableType : null);
}
void ResurrectCandidates(DirectReferenceVisitor forwardVisitor,
DirectReferenceVisitor resurrectVisitor,
bool copyFirst)
{
#if !(REFERENCE_COUNTING_GC || DEFERRED_REFERENCE_COUNTING_GC)
UIntPtr[] runTable = null;
int runTableIndex = 0;
int runIndex = 0;
// For the concurrent collector, ResurrectCandidates could happen
// while the application threads are calling SuppressFinalize and
// ReRegisterForFinalize. So we need to use the spinLock to prevent
// races. But we do not want to hold the spinLock while allocating
// (i.e. when we grow the RunFinalizerTable[Shadow]) because our
// spinLock is a leaf lock. We don't want to worry about deadlocks
// involving the spinLock and any locking that occurs as part of a
// GC provoked by an allocation attempt.
#if SINGULARITY
bool disabled = Processor.DisableLocalPreemption();
#endif
spinLock.Acquire();
bool lockHeld = true;
try {
int logicalIndex = 0;
for (int i = 0; i < CandidateTableShadow.Length; i++)
{
UIntPtr[] table = copyFirst
? CandidateTable[i]
: CandidateTableShadow[i];
if (table == null)
{
VTable.Assert(logicalIndex == lastCandidateIndex);
break;
}
for (int j = 0; j < table.Length; j++, logicalIndex++)
{
if (table[j] == UIntPtr.Zero)
{
VTable.Assert(logicalIndex == lastCandidateIndex);
break;
}
fixed(UIntPtr *loc = &table[j])
{
if (!IsLink((int)*loc))
{
UIntPtr oldVal = *loc;
forwardVisitor.Visit(loc);
if (*loc == UIntPtr.Zero)
{
// Put this slot onto the CandidateTable's free list
*loc = (UIntPtr)freeCandidateLink;
freeCandidateLink = IndexToLink(logicalIndex);
// marching forward through the RunFinalizer[Shadow] table, find an
// empty slot to install this object. Maintain the cursor across
// objects, so we can efficiently transfer an entire batch.
for (; runTableIndex < RunFinalizerTableShadow.Length; runTableIndex++)
{
runTable = copyFirst
? RunFinalizerTable[runTableIndex]
: RunFinalizerTableShadow[runTableIndex];
if (runTable == null)
{
// Create a new table
int length = RunFinalizerTableShadow[runTableIndex - 1].Length * 2;
lockHeld = false;
spinLock.Release();
#if SINGULARITY
Processor.RestoreLocalPreemption(disabled);
#endif
UIntPtr[] newTable = new UIntPtr[length];
#if SINGULARITY
disabled = Processor.DisableLocalPreemption();
#endif
spinLock.Acquire();
lockHeld = true;
// There is no race with the RunFinalizerTable[Shadow].
// The spinLock serializes access to the CandidateTable[Shadow].
runTable = newTable;
RunFinalizerTable[runTableIndex] = newTable;
RunFinalizerTableShadow[runTableIndex] = newTable;
UIntPtr tableAddr = Magic.addressOf(newTable);
resurrectVisitor.Visit(&tableAddr);
resurrectVisitor.VisitReferenceFields(RunFinalizerTable[runTableIndex]);
resurrectVisitor.VisitReferenceFields(RunFinalizerTableShadow[runTableIndex]);
}
for (; runIndex < runTable.Length; runIndex++)
{
if (runTable[runIndex] == UIntPtr.Zero)
{
goto outer;
}
}
runIndex -= runTable.Length;
VTable.Assert(runIndex == 0); // ready for next sub-table
}
outer:
// We found an empty slot in the RunFinalizerTable[Shadow],
// where we can put our ready Candidate. It's also possible
// to reach this label by falling through after exhausting the
// entire table. This will result in an exception when we
// attempt to over-index the array. It's not clear what more
// protections are required... the process has exceeded an
// unlikely and hard-wired capacity limit.
Interlocked.Increment(ref WaitingToRun);
madeRunnable = true;
if (copyFirst)
{
RunFinalizerTable[runTableIndex][runIndex]
= oldVal | new UIntPtr(1);
}
else
{
RunFinalizerTableShadow[runTableIndex][runIndex]
= oldVal | new UIntPtr(1);
}
}
}
}
}
}
}
finally {
if (lockHeld)
{
spinLock.Release();
#if SINGULARITY
Processor.RestoreLocalPreemption(disabled);
#endif
}
}
if (madeRunnable)
{
// Resurrect objects!
VisitAllRunFinalizer(resurrectVisitor, copyFirst, true);
}
#endif // REFERENCE_COUNTING_GC
}
/// <summary>
/// Check if the first stack height represents a deeper location on the
/// stack.
/// </summary>
/// <param name="first">The first stack height to compare.</param>
/// <param name="second">The second stack height to compare.</param>
/// <returns>True iff the first height is deeper in the stack than the
/// second height.</returns>
internal static bool Deeper(StackHeight first, StackHeight second)
{
VTable.Assert(first.stackPointer != UIntPtr.Zero);
VTable.Assert(second.stackPointer != UIntPtr.Zero);
return(first.stackPointer <= second.stackPointer);
}
internal static String AllocateString(int stringLength,
Thread currentThread)
{
VTable.Deny(Transitions.UnderGCControl(currentThread.threadIndex));
return(installedGC.AllocateString(stringLength, currentThread));
}
internal static Array AllocateArray(VTable vtable, int rank,
int totalElements)
{
return(AllocateArray(vtable, rank, totalElements,
Thread.CurrentThread));
}
internal static Array AllocateVector(VTable vtable, int numElements)
{
return(AllocateVector(vtable, numElements, Thread.CurrentThread));
}
internal static Object AllocateObjectNoInline(VTable vtable,
Thread currentThread)
{
return(AllocateObject(vtable, currentThread));
}
internal static Object AllocateObject(VTable vtable,
Thread currentThread)
{
VTable.Deny(Transitions.UnderGCControl(currentThread.threadIndex));
return(installedGC.AllocateObject(vtable, currentThread));
}
internal static Object AllocateObjectNoInline(VTable vtable)
{
return(AllocateObject(vtable));
}
internal static void DebugPrint(String v, __arglist)
{
VTable.DebugPrint(v, new ArgIterator(__arglist));
}
//////////////////////////////////////////////////////////////////////
//
internal static IntPtr FixedAlloc(int sizetdwBytes)
{
VTable.DebugBreak();
return(IntPtr.Zero);
}
private static int LinkToIndex(int link)
{
VTable.Assert(IsLink(link));
return(link >> 1);
}
internal static void FixedFree(IntPtr handle)
{
VTable.DebugBreak();
}
internal static void RegisterCandidate(Object obj)
{
#if !(REFERENCE_COUNTING_GC || DEFERRED_REFERENCE_COUNTING_GC)
UIntPtr objPtr = Magic.addressOf(obj);
UIntPtr page = PageTable.Page(objPtr);
if (!PageTable.IsGcPage(page))
{
return;
}
// It's tempting to do all manipulations of the CandidateTable with Interlocked
// operations, but it would leave us open to the ABA problem. For example,
//
// candidateFreeList points to slot 5, which points to slot 7, and then 9.
// We start our CompareExchange loop based on these facts.
// Another thread intervenes. It:
// Allocates slot 5 from the free list.
// Allocates slot 7 from the free list, so 9 is now at the top.
// It calls SuppressCandidate on #5, putting it back on the list,
// pointing at 9.
// Our thread performs the CompareExchange, removing 5 from the list &
// establishing 7 as the head.
//
// In order to avoid these (admittedly unlikely) corruptions, just use a
// SpinLock to serialize all modifications of the CandidateTable. But to
// keep the SpinLock as a leaf lock and avoid deadlocks, ensure that we
// never allocate or do anything else significant while holding the lock.
#if SINGULARITY
bool disabled = Processor.DisableLocalPreemption();
#endif
spinLock.Acquire();
bool lockHeld = true;
try {
restart:
// Set index to point into the table at a free spot.
int index = 0;
UIntPtr[] table = null;
// Grab from the free list. Note that our free list can never be empty.
// That's because it points either down a linked chain of previously allocated
// and since free'd entries, or it points out past the high water mark. We
// may need to allocate memory to back that index, but the free list always
// contains at least a virtual index. And the slot that points past the
// high water mark is always the last slot to be consumed from the free
// list, so we grow only as a last resort.
int logicalIndex = index = LinkToIndex(freeCandidateLink);
// Relate that global index to a table and a local index.
for (int i = 0; i < CandidateTable.Length; i++)
{
table = CandidateTable[i];
if (table == null)
{
// Must be the first index into a new table. We're going to
// create the new table, but we don't want to hold the spinLock
// during the create. (We want the spinLock to be a leaf lock
// that cannot interact with any GC locks to cause deadlock).
VTable.Assert(index == 0);
lockHeld = false;
spinLock.Release();
#if SINGULARITY
Processor.RestoreLocalPreemption(disabled);
#endif
table = new UIntPtr[CandidateTable[i - 1].Length * 2];
#if SINGULARITY
disabled = Processor.DisableLocalPreemption();
#endif
spinLock.Acquire();
lockHeld = true;
// There is a race here. If we lose the race, someone else will
// have extended the table. If so, we use their official table and
// let the GC collect our extra one. No need for interlocked
// operations since we are back inside the spinLock.
if (CandidateTable[i] == null)
{
CandidateTable[i] = table;
}
// Regardless, the world has changed.
goto restart;
}
// Are we extending or are we chasing previously allocated empty slots?
if (index < table.Length)
{
if (logicalIndex >= lastCandidateIndex)
{
// we are extending past the high water mark. Grow the free list
// ahead of us by 1 slot.
VTable.Assert(logicalIndex == lastCandidateIndex);
lastCandidateIndex = logicalIndex + 1;
freeCandidateLink = IndexToLink(lastCandidateIndex);
}
else
{
// We are consuming the free list
freeCandidateLink = (int)table[index];
VTable.Assert(IsLink(freeCandidateLink));
}
break;
}
index -= table.Length; // on to the next table
}
VTable.Assert(table != null, "Candidate Algorithmic inconsistency");
// We have found the table!
table[index] = Magic.addressOf(obj);
// The following looks like a 64-bit porting issue (32-bit truncation).
// But actually I'm just ensuring that object pointers have the low bit
// cleared.
VTable.Assert(!IsLink((int)objPtr));
}
finally {
if (lockHeld)
{
spinLock.Release();
#if SINGULARITY
Processor.RestoreLocalPreemption(disabled);
#endif
}
}
#endif // REFERENCE_COUNTING_GC
}
internal void Allocate(Delegate del)
{
VTable.Assert(this.del == null);
this.del = del;
}
internal RuntimeType()
{
VTable.NotReached("RuntimeType constructor not supported");
}
internal void DeAllocate(int nextIdx)
{
VTable.Assert(this.del != null);
this.del = null;
this.nextIdx = nextIdx;
}
extern private static Object AllocateObject(VTable vtable);
internal Delegate Delegate()
{
VTable.Assert(this.del != null);
return(this.del);
}
public static void Assert(bool truth)
{
VTable.Assert(truth);
}
internal int NextIdx()
{
VTable.Assert(this.del == null);
return(this.nextIdx);
}
public TRef(Object o)
{
VTable.Assert(o != null);
this.o = o;
}
static GC() // Class Constructor (cctor)
{
GC.Initialize();
switch (gcType)
{
#if !SINGULARITY || ADAPTIVE_COPYING_COLLECTOR
case GCType.AdaptiveCopyingCollector: {
AdaptiveCopyingCollector.Initialize();
GC.installedGC = AdaptiveCopyingCollector.instance;
break;
}
#endif
#if !SINGULARITY || MARK_SWEEP_COLLECTOR
case GCType.MarkSweepCollector: {
MarkSweepCollector.Initialize();
GC.installedGC = MarkSweepCollector.instance;
break;
}
#endif
#if !SINGULARITY || TABLE_MARK_SWEEP_COLLECTOR
case GCType.TableMarkSweepCollector: {
SimpleMarkSweepCollector.Initialize();
GC.installedGC = SimpleMarkSweepCollector.instance;
break;
}
#endif
#if !SINGULARITY || SEMISPACE_COLLECTOR
case GCType.SemispaceCollector: {
SemispaceCollector.Initialize();
GC.installedGC = SemispaceCollector.instance;
break;
}
#endif
#if !SINGULARITY || SLIDING_COLLECTOR
case GCType.SlidingCollector: {
SlidingCollector.Initialize();
GC.installedGC = SlidingCollector.instance;
break;
}
#endif
#if !SINGULARITY || CONCURRENT_MS_COLLECTOR
case GCType.ConcurrentMSCollector: {
ConcurrentMSCollector.Initialize();
GC.installedGC = ConcurrentMSCollector.instance;
break;
}
#endif
#if !SINGULARITY || ATOMIC_RC_COLLECTOR
case GCType.AtomicRCCollector: {
AtomicRCCollector.Initialize();
GC.installedGC = AtomicRCCollector.instance;
break;
}
#endif
#if !SINGULARITY
case GCType.ReferenceCountingCollector: {
ReferenceCountingCollector.Initialize();
GC.installedGC = ReferenceCountingCollector.instance;
break;
}
#endif
#if !SINGULARITY
case GCType.DeferredReferenceCountingCollector: {
DeferredReferenceCountingCollector.Initialize();
GC.installedGC = DeferredReferenceCountingCollector.instance;
break;
}
#endif
#if !SINGULARITY || NULL_COLLECTOR
case GCType.NullCollector: {
VTable.Assert(wbType == 0, "No need for a write barrier");
GC.installedGC =
(NullCollector)
BootstrapMemory.Allocate(typeof(NullCollector));
break;
}
#endif
#if !SINGULARITY
case GCType.CoCoMSCollector: {
CoCoMSCollector.Initialize();
GC.installedGC = CoCoMSCollector.instance;
break;
}
#endif
default: {
VTable.NotReached("Unknown GC type: " + gcType);
break;
}
}
GC.installedGC.NewThreadNotification(Thread.initialThread, true);
GC.installedGC.ThreadStartNotification(Thread.initialThread.threadIndex);
}