codeversion.cpp

// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// ===========================================================================
// File: CodeVersion.cpp
//
// ===========================================================================

#include "common.h"
#include "codeversion.h"
#include "patchpointinfo.h"

#ifdef FEATURE_CODE_VERSIONING
#include "threadsuspend.h"
#include "methoditer.h"
#include "../debug/ee/debugger.h"
#include "../debug/ee/walker.h"
#include "../debug/ee/controller.h"
#endif // FEATURE_CODE_VERSIONING

#ifndef FEATURE_CODE_VERSIONING

//
// When not using code versioning we've got a minimal implementation of
// NativeCodeVersion that simply wraps a MethodDesc* with no additional
// versioning information
//

NativeCodeVersion::NativeCodeVersion(PTR_MethodDesc pMethod) : m_pMethodDesc(pMethod) {}
BOOL NativeCodeVersion::IsDefaultVersion() const { return TRUE; }
PCODE NativeCodeVersion::GetNativeCode() const { return m_pMethodDesc->GetNativeCode(); }

#ifndef DACCESS_COMPILE
BOOL NativeCodeVersion::SetNativeCodeInterlocked(PCODE pCode, PCODE pExpected) { return m_pMethodDesc->SetNativeCodeInterlocked(pCode, pExpected); }
#endif

#ifdef HAVE_GCCOVER
PTR_GCCoverageInfo NativeCodeVersion::GetGCCoverageInfo() const { return GetMethodDesc()->m_GcCover; }
void NativeCodeVersion::SetGCCoverageInfo(PTR_GCCoverageInfo gcCover)
{
    MethodDesc *pMD = GetMethodDesc();
    _ASSERTE(gcCover == NULL || pMD->m_GcCover == NULL);
    pMD->m_GcCover = gcCover;
}
#endif


#else // FEATURE_CODE_VERSIONING

// This is just used as a unique id. Overflow is OK. If we happen to have more than 4+Billion rejits
// and somehow manage to not run out of memory, we'll just have to redefine ReJITID as size_t.
/* static */
static ReJITID s_GlobalReJitId = 1;

#ifndef DACCESS_COMPILE
NativeCodeVersionNode::NativeCodeVersionNode(
    NativeCodeVersionId id,
    MethodDesc* pMethodDesc,
    ReJITID parentId,
    NativeCodeVersion::OptimizationTier optimizationTier,
    PatchpointInfo* patchpointInfo,
    unsigned ilOffset)
    :
    m_pNativeCode{},
    m_pMethodDesc(pMethodDesc),
    m_parentId(parentId),
    m_pNextMethodDescSibling(NULL),
    m_id(id),
#ifdef FEATURE_TIERED_COMPILATION
    m_optTier(optimizationTier),
#endif
#ifdef HAVE_GCCOVER
    m_gcCover(PTR_NULL),
#endif
#ifdef FEATURE_ON_STACK_REPLACEMENT
    m_patchpointInfo(patchpointInfo),
    m_ilOffset(ilOffset),
#endif
    m_flags(0)
{}
#endif

PCODE NativeCodeVersionNode::GetNativeCode() const
{
    LIMITED_METHOD_DAC_CONTRACT;
    return m_pNativeCode;
}

ReJITID NativeCodeVersionNode::GetILVersionId() const
{
    LIMITED_METHOD_DAC_CONTRACT;
    return m_parentId;
}

ILCodeVersion NativeCodeVersionNode::GetILCodeVersion() const
{
    LIMITED_METHOD_DAC_CONTRACT;
    PTR_MethodDesc pMD = GetMethodDesc();
    return pMD->GetCodeVersionManager()->GetILCodeVersion(pMD, GetILVersionId());
}

NativeCodeVersionId NativeCodeVersionNode::GetVersionId() const
{
    LIMITED_METHOD_DAC_CONTRACT;
    return m_id;
}

#ifndef DACCESS_COMPILE
BOOL NativeCodeVersionNode::SetNativeCodeInterlocked(PCODE pCode, PCODE pExpected)
{
    LIMITED_METHOD_CONTRACT;
    return InterlockedCompareExchangeT(&m_pNativeCode,
        (TADDR&)pCode, (TADDR&)pExpected) == (TADDR&)pExpected;
}
#endif

BOOL NativeCodeVersionNode::IsActiveChildVersion() const
{
    LIMITED_METHOD_DAC_CONTRACT;
    _ASSERTE(CodeVersionManager::IsLockOwnedByCurrentThread());
    return (m_flags & IsActiveChildFlag) != 0;
}

#ifndef DACCESS_COMPILE
void NativeCodeVersionNode::SetActiveChildFlag(BOOL isActive)
{
    LIMITED_METHOD_CONTRACT;
    _ASSERTE(CodeVersionManager::IsLockOwnedByCurrentThread());
    if (isActive)
    {
        m_flags |= IsActiveChildFlag;
    }
    else
    {
        m_flags &= ~IsActiveChildFlag;
    }
}
#endif


#ifdef FEATURE_TIERED_COMPILATION

NativeCodeVersion::OptimizationTier NativeCodeVersionNode::GetOptimizationTier() const
{
    LIMITED_METHOD_DAC_CONTRACT;
    return m_optTier;
}

#ifndef DACCESS_COMPILE
void NativeCodeVersionNode::SetOptimizationTier(NativeCodeVersion::OptimizationTier tier)
{
    LIMITED_METHOD_CONTRACT;

    _ASSERTE(
        tier == m_optTier ||
        (m_optTier != NativeCodeVersion::OptimizationTier::OptimizationTier1 &&
         m_optTier != NativeCodeVersion::OptimizationTier::OptimizationTierOptimized));

    m_optTier = tier;
}
#endif

#endif // FEATURE_TIERED_COMPILATION

#ifdef FEATURE_ON_STACK_REPLACEMENT

PatchpointInfo* NativeCodeVersionNode::GetOSRInfo(unsigned * ilOffset) const
{
    LIMITED_METHOD_DAC_CONTRACT;
    *ilOffset = m_ilOffset;
    return m_patchpointInfo;
}

#endif // FEATURE_ON_STACK_REPLACEMENT

#ifdef HAVE_GCCOVER

PTR_GCCoverageInfo NativeCodeVersionNode::GetGCCoverageInfo() const
{
    LIMITED_METHOD_CONTRACT;
    return m_gcCover;
}

void NativeCodeVersionNode::SetGCCoverageInfo(PTR_GCCoverageInfo gcCover)
{
    LIMITED_METHOD_CONTRACT;
    _ASSERTE(gcCover == NULL || m_gcCover == NULL);

    m_gcCover = gcCover;
}

#endif // HAVE_GCCOVER

NativeCodeVersion::NativeCodeVersion(PTR_NativeCodeVersionNode pVersionNode) :
    m_storageKind(pVersionNode != NULL ? StorageKind::Explicit : StorageKind::Unknown),
    m_pVersionNode(pVersionNode)
{}

NativeCodeVersion::NativeCodeVersion(PTR_MethodDesc pMethod) :
    m_storageKind(pMethod != NULL ? StorageKind::Synthetic : StorageKind::Unknown)
{
    LIMITED_METHOD_DAC_CONTRACT;
    m_synthetic.m_pMethodDesc = pMethod;
}

BOOL NativeCodeVersion::IsDefaultVersion() const
{
    LIMITED_METHOD_DAC_CONTRACT;
    return m_storageKind == StorageKind::Synthetic;
}

PCODE NativeCodeVersion::GetNativeCode() const
{
    LIMITED_METHOD_DAC_CONTRACT;
    if (m_storageKind == StorageKind::Explicit)
    {
        return AsNode()->GetNativeCode();
    }
    else
    {
        return GetMethodDesc()->GetNativeCode();
    }
}

ReJITID NativeCodeVersion::GetILCodeVersionId() const
{
    LIMITED_METHOD_DAC_CONTRACT;
    if (m_storageKind == StorageKind::Explicit)
    {
        return AsNode()->GetILVersionId();
    }
    else
    {
        return 0;
    }
}

ILCodeVersion NativeCodeVersion::GetILCodeVersion() const
{
    LIMITED_METHOD_DAC_CONTRACT;
    if (m_storageKind == StorageKind::Explicit)
    {
        return AsNode()->GetILCodeVersion();
    }
    else
    {
        PTR_MethodDesc pMethod = GetMethodDesc();
        return ILCodeVersion(dac_cast<PTR_Module>(pMethod->GetModule()), pMethod->GetMemberDef());
    }
}

#ifndef DACCESS_COMPILE
BOOL NativeCodeVersion::SetNativeCodeInterlocked(PCODE pCode, PCODE pExpected)
{
    LIMITED_METHOD_CONTRACT;
    if (m_storageKind == StorageKind::Explicit)
    {
        return AsNode()->SetNativeCodeInterlocked(pCode, pExpected);
    }
    else
    {
        return GetMethodDesc()->SetNativeCodeInterlocked(pCode, pExpected);
    }
}
#endif

BOOL NativeCodeVersion::IsActiveChildVersion() const
{
    LIMITED_METHOD_DAC_CONTRACT;
    if (m_storageKind == StorageKind::Explicit)
    {
        return AsNode()->IsActiveChildVersion();
    }
    else
    {
        MethodDescVersioningState* pMethodVersioningState = GetMethodDescVersioningState();
        if (pMethodVersioningState == NULL)
        {
            return TRUE;
        }
        return pMethodVersioningState->IsDefaultVersionActiveChild();
    }
}

PTR_MethodDescVersioningState NativeCodeVersion::GetMethodDescVersioningState() const
{
    LIMITED_METHOD_DAC_CONTRACT;
    PTR_MethodDesc pMethodDesc = GetMethodDesc();
    CodeVersionManager* pCodeVersionManager = pMethodDesc->GetCodeVersionManager();
    return pCodeVersionManager->GetMethodDescVersioningState(pMethodDesc);
}

#ifndef DACCESS_COMPILE
void NativeCodeVersion::SetActiveChildFlag(BOOL isActive)
{
    LIMITED_METHOD_DAC_CONTRACT;
    if (m_storageKind == StorageKind::Explicit)
    {
        if (isActive &&
            !CodeVersionManager::InitialNativeCodeVersionMayNotBeTheDefaultNativeCodeVersion() &&
            GetMethodDesc()->GetNativeCode() == (PCODE)NULL)
        {
            CodeVersionManager::SetInitialNativeCodeVersionMayNotBeTheDefaultNativeCodeVersion();
        }

        AsNode()->SetActiveChildFlag(isActive);
    }
    else
    {
        MethodDescVersioningState* pMethodVersioningState = GetMethodDescVersioningState();
        pMethodVersioningState->SetDefaultVersionActiveChildFlag(isActive);
    }
}

MethodDescVersioningState* NativeCodeVersion::GetMethodDescVersioningState()
{
    LIMITED_METHOD_DAC_CONTRACT;
    MethodDesc* pMethodDesc = GetMethodDesc();
    CodeVersionManager* pCodeVersionManager = pMethodDesc->GetCodeVersionManager();
    return pCodeVersionManager->GetMethodDescVersioningState(pMethodDesc);
}
#endif

#ifdef FEATURE_TIERED_COMPILATION

NativeCodeVersion::OptimizationTier NativeCodeVersion::GetOptimizationTier() const
{
    LIMITED_METHOD_DAC_CONTRACT;
    if (m_storageKind == StorageKind::Explicit)
    {
        return AsNode()->GetOptimizationTier();
    }
    else
    {
        return TieredCompilationManager::GetInitialOptimizationTier(GetMethodDesc());
    }
}

bool NativeCodeVersion::IsFinalTier() const
{
    LIMITED_METHOD_DAC_CONTRACT;
    OptimizationTier tier = GetOptimizationTier();
    return tier == OptimizationTier1 || tier == OptimizationTierOptimized;
}

#ifndef DACCESS_COMPILE
void NativeCodeVersion::SetOptimizationTier(OptimizationTier tier)
{
    WRAPPER_NO_CONTRACT;
    if (m_storageKind == StorageKind::Explicit)
    {
        AsNode()->SetOptimizationTier(tier);
    }
    else
    {
        // State changes should have been made previously such that the initial tier is the new tier
        _ASSERTE(TieredCompilationManager::GetInitialOptimizationTier(GetMethodDesc()) == tier);
    }
}
#endif

#endif

#ifdef FEATURE_ON_STACK_REPLACEMENT

PatchpointInfo * NativeCodeVersion::GetOSRInfo(unsigned * ilOffset)
{
    LIMITED_METHOD_DAC_CONTRACT;
    if (m_storageKind == StorageKind::Explicit)
    {
        return AsNode()->GetOSRInfo(ilOffset);
    }
    else
    {
        return NULL;
    }
}

#endif


#ifdef HAVE_GCCOVER

PTR_GCCoverageInfo NativeCodeVersion::GetGCCoverageInfo() const
{
    WRAPPER_NO_CONTRACT;

    if (m_storageKind == StorageKind::Explicit)
    {
        return AsNode()->GetGCCoverageInfo();
    }
    else
    {
        return GetMethodDesc()->m_GcCover;
    }
}

void NativeCodeVersion::SetGCCoverageInfo(PTR_GCCoverageInfo gcCover)
{
    WRAPPER_NO_CONTRACT;

    if (m_storageKind == StorageKind::Explicit)
    {
        AsNode()->SetGCCoverageInfo(gcCover);
    }
    else
    {
        MethodDesc *pMD = GetMethodDesc();
        _ASSERTE(gcCover == NULL || pMD->m_GcCover == NULL);
        pMD->m_GcCover = gcCover;
    }
}

#endif // HAVE_GCCOVER

PTR_NativeCodeVersionNode NativeCodeVersion::AsNode() const
{
    LIMITED_METHOD_DAC_CONTRACT;
    if (m_storageKind == StorageKind::Explicit)
    {
        return m_pVersionNode;
    }
    else
    {
        return NULL;
    }
}

#ifndef DACCESS_COMPILE
PTR_NativeCodeVersionNode NativeCodeVersion::AsNode()
{
    LIMITED_METHOD_CONTRACT;
    if (m_storageKind == StorageKind::Explicit)
    {
        return m_pVersionNode;
    }
    else
    {
        return NULL;
    }
}
#endif

NativeCodeVersionCollection::NativeCodeVersionCollection(PTR_MethodDesc pMethodDescFilter, ILCodeVersion ilCodeFilter) :
    m_pMethodDescFilter(pMethodDescFilter),
    m_ilCodeFilter(ilCodeFilter)
{
}

NativeCodeVersionIterator NativeCodeVersionCollection::Begin()
{
    LIMITED_METHOD_DAC_CONTRACT;
    return NativeCodeVersionIterator(this);
}
NativeCodeVersionIterator NativeCodeVersionCollection::End()
{
    LIMITED_METHOD_DAC_CONTRACT;
    return NativeCodeVersionIterator(NULL);
}

NativeCodeVersionIterator::NativeCodeVersionIterator(NativeCodeVersionCollection* pNativeCodeVersionCollection) :
    m_stage(IterationStage::Initial),
    m_pCollection(pNativeCodeVersionCollection),
    m_pLinkedListCur(dac_cast<PTR_NativeCodeVersionNode>(nullptr))
{
    LIMITED_METHOD_DAC_CONTRACT;
    First();
}
void NativeCodeVersionIterator::First()
{
    LIMITED_METHOD_DAC_CONTRACT;
    if (m_pCollection == NULL)
    {
        m_stage = IterationStage::End;
    }
    Next();
}
void NativeCodeVersionIterator::Next()
{
    LIMITED_METHOD_DAC_CONTRACT;
    if (m_stage == IterationStage::Initial)
    {
        ILCodeVersion ilCodeFilter = m_pCollection->m_ilCodeFilter;
        m_stage = IterationStage::ImplicitCodeVersion;
        if (ilCodeFilter.IsNull() || ilCodeFilter.IsDefaultVersion())
        {
            m_cur = NativeCodeVersion(m_pCollection->m_pMethodDescFilter);
            return;
        }
    }
    if (m_stage == IterationStage::ImplicitCodeVersion)
    {
        m_stage = IterationStage::LinkedList;
        CodeVersionManager* pCodeVersionManager = m_pCollection->m_pMethodDescFilter->GetCodeVersionManager();
        MethodDescVersioningState* pMethodDescVersioningState = pCodeVersionManager->GetMethodDescVersioningState(m_pCollection->m_pMethodDescFilter);
        if (pMethodDescVersioningState == NULL)
        {
            m_pLinkedListCur = NULL;
        }
        else
        {
            ILCodeVersion ilCodeFilter = m_pCollection->m_ilCodeFilter;
            m_pLinkedListCur = pMethodDescVersioningState->GetFirstVersionNode();
            while (m_pLinkedListCur != NULL && !ilCodeFilter.IsNull() && ilCodeFilter.GetVersionId() != m_pLinkedListCur->GetILVersionId())
            {
                m_pLinkedListCur = m_pLinkedListCur->m_pNextMethodDescSibling;
            }
        }
        if (m_pLinkedListCur != NULL)
        {
            m_cur = NativeCodeVersion(m_pLinkedListCur);
            return;
        }
    }
    if (m_stage == IterationStage::LinkedList)
    {
        if (m_pLinkedListCur != NULL)
        {
            ILCodeVersion ilCodeFilter = m_pCollection->m_ilCodeFilter;
            do
            {
                m_pLinkedListCur = m_pLinkedListCur->m_pNextMethodDescSibling;
            } while (m_pLinkedListCur != NULL && !ilCodeFilter.IsNull() && ilCodeFilter.GetVersionId() != m_pLinkedListCur->GetILVersionId());
        }
        if (m_pLinkedListCur != NULL)
        {
            m_cur = NativeCodeVersion(m_pLinkedListCur);
            return;
        }
        else
        {
            m_stage = IterationStage::End;
            m_cur = NativeCodeVersion();
        }
    }
}
const NativeCodeVersion & NativeCodeVersionIterator::Get() const
{
    LIMITED_METHOD_DAC_CONTRACT;
    return m_cur;
}
bool NativeCodeVersionIterator::Equal(const NativeCodeVersionIterator &i) const
{
    LIMITED_METHOD_DAC_CONTRACT;
    return m_cur == i.m_cur;
}

ILCodeVersionNode::ILCodeVersionNode() :
    m_pModule(dac_cast<PTR_Module>(nullptr)),
    m_methodDef(0),
    m_rejitId(0),
    m_pNextILVersionNode(dac_cast<PTR_ILCodeVersionNode>(nullptr)),
    m_rejitState(RejitFlags::kStateRequested),
    m_pIL(),
    m_jitFlags(0),
    m_deoptimized(FALSE)
{
    m_pIL.Store(dac_cast<PTR_COR_ILMETHOD>(nullptr));
}

#ifndef DACCESS_COMPILE
ILCodeVersionNode::ILCodeVersionNode(Module* pModule, mdMethodDef methodDef, ReJITID id, BOOL isDeoptimized) :
    m_pModule(pModule),
    m_methodDef(methodDef),
    m_rejitId(id),
    m_pNextILVersionNode(dac_cast<PTR_ILCodeVersionNode>(nullptr)),
    m_rejitState(RejitFlags::kStateRequested),
    m_pIL(nullptr),
    m_jitFlags(0),
    m_deoptimized(isDeoptimized)
{}
#endif

PTR_Module ILCodeVersionNode::GetModule() const
{
    LIMITED_METHOD_DAC_CONTRACT;
    return m_pModule;
}

mdMethodDef ILCodeVersionNode::GetMethodDef() const
{
    LIMITED_METHOD_DAC_CONTRACT;
    return m_methodDef;
}

ReJITID ILCodeVersionNode::GetVersionId() const
{
    LIMITED_METHOD_DAC_CONTRACT;
    return m_rejitId;
}

RejitFlags ILCodeVersionNode::GetRejitState() const
{
    LIMITED_METHOD_DAC_CONTRACT;
    return m_rejitState.Load() & RejitFlags::kStateMask;
}

BOOL ILCodeVersionNode::GetEnableReJITCallback() const
{
    LIMITED_METHOD_DAC_CONTRACT;

    return (m_rejitState.Load() & RejitFlags::kSuppressParams) == RejitFlags::kSuppressParams;
}

PTR_COR_ILMETHOD ILCodeVersionNode::GetIL() const
{
    LIMITED_METHOD_DAC_CONTRACT;
    return dac_cast<PTR_COR_ILMETHOD>(m_pIL.Load());
}

DWORD ILCodeVersionNode::GetJitFlags() const
{
    LIMITED_METHOD_DAC_CONTRACT;
    return m_jitFlags.Load();
}

const InstrumentedILOffsetMapping* ILCodeVersionNode::GetInstrumentedILMap() const
{
    LIMITED_METHOD_DAC_CONTRACT;
    return &m_instrumentedILMap;
}

PTR_ILCodeVersionNode ILCodeVersionNode::GetNextILVersionNode() const
{
    LIMITED_METHOD_DAC_CONTRACT;
    return m_pNextILVersionNode;
}

BOOL ILCodeVersionNode::IsDeoptimized() const
{
    LIMITED_METHOD_DAC_CONTRACT;
    return m_deoptimized;
}

#ifndef DACCESS_COMPILE
void ILCodeVersionNode::SetRejitState(RejitFlags newState)
{
    LIMITED_METHOD_CONTRACT;
    // We're doing a non thread safe modification to m_rejitState
    _ASSERTE(CodeVersionManager::IsLockOwnedByCurrentThread());

    RejitFlags oldNonMaskFlags = m_rejitState.Load() & ~RejitFlags::kStateMask;
    m_rejitState.Store(static_cast<RejitFlags>(newState | oldNonMaskFlags));
}

void ILCodeVersionNode::SetEnableReJITCallback(BOOL state)
{
    LIMITED_METHOD_CONTRACT;
    // We're doing a non thread safe modification to m_rejitState
    _ASSERTE(CodeVersionManager::IsLockOwnedByCurrentThread());

    RejitFlags oldFlags = m_rejitState.Load();
    if (state)
    {
        m_rejitState.Store(oldFlags | RejitFlags::kSuppressParams);
    }
    else
    {
        m_rejitState.Store(oldFlags & ~RejitFlags::kSuppressParams);
    }
}

void ILCodeVersionNode::SetIL(COR_ILMETHOD* pIL)
{
    LIMITED_METHOD_CONTRACT;
    m_pIL.Store(pIL);
}

void ILCodeVersionNode::SetJitFlags(DWORD flags)
{
    LIMITED_METHOD_CONTRACT;
    m_jitFlags.Store(flags);
}

void ILCodeVersionNode::SetInstrumentedILMap(SIZE_T cMap, COR_IL_MAP * rgMap)
{
    LIMITED_METHOD_CONTRACT;
    _ASSERTE(CodeVersionManager::IsLockOwnedByCurrentThread());
    m_instrumentedILMap.SetMappingInfo(cMap, rgMap);
}

void ILCodeVersionNode::SetNextILVersionNode(ILCodeVersionNode* pNextILVersionNode)
{
    LIMITED_METHOD_CONTRACT;
    _ASSERTE(CodeVersionManager::IsLockOwnedByCurrentThread());
    m_pNextILVersionNode = pNextILVersionNode;
}
#endif

ILCodeVersion::ILCodeVersion() :
    m_storageKind(StorageKind::Unknown)
{}

ILCodeVersion::ILCodeVersion(const ILCodeVersion & ilCodeVersion) :
    m_storageKind(ilCodeVersion.m_storageKind)
{
    if(m_storageKind == StorageKind::Explicit)
    {
        m_pVersionNode = ilCodeVersion.m_pVersionNode;
    }
    else if(m_storageKind == StorageKind::Synthetic)
    {
        m_synthetic = ilCodeVersion.m_synthetic;
    }
}

ILCodeVersion::ILCodeVersion(PTR_ILCodeVersionNode pILCodeVersionNode) :
    m_storageKind(pILCodeVersionNode != NULL ? StorageKind::Explicit : StorageKind::Unknown),
    m_pVersionNode(pILCodeVersionNode)
{}

ILCodeVersion::ILCodeVersion(PTR_Module pModule, mdMethodDef methodDef) :
    m_storageKind(pModule != NULL ? StorageKind::Synthetic : StorageKind::Unknown)
{
    LIMITED_METHOD_DAC_CONTRACT;
    m_synthetic.m_pModule = pModule;
    m_synthetic.m_methodDef = methodDef;
}

bool ILCodeVersion::operator==(const ILCodeVersion & rhs) const
{
    LIMITED_METHOD_DAC_CONTRACT;
    if (m_storageKind == StorageKind::Explicit)
    {
        return (rhs.m_storageKind == StorageKind::Explicit) &&
            (AsNode() == rhs.AsNode());
    }
    else if (m_storageKind == StorageKind::Synthetic)
    {
        return (rhs.m_storageKind == StorageKind::Synthetic) &&
            (m_synthetic.m_pModule == rhs.m_synthetic.m_pModule) &&
            (m_synthetic.m_methodDef == rhs.m_synthetic.m_methodDef);
    }
    else
    {
        return rhs.m_storageKind == StorageKind::Unknown;
    }
}

BOOL ILCodeVersion::HasDefaultIL() const
{
    LIMITED_METHOD_CONTRACT;

    return (m_storageKind == StorageKind::Synthetic) || (AsNode()->GetIL() == NULL);
}

BOOL ILCodeVersion::IsNull() const
{
    LIMITED_METHOD_DAC_CONTRACT;
    return m_storageKind == StorageKind::Unknown;
}

BOOL ILCodeVersion::IsDefaultVersion() const
{
    LIMITED_METHOD_DAC_CONTRACT;
    return m_storageKind == StorageKind::Synthetic;
}

PTR_Module ILCodeVersion::GetModule() const
{
    LIMITED_METHOD_DAC_CONTRACT;
    if (m_storageKind == StorageKind::Explicit)
    {
        return AsNode()->GetModule();
    }
    else
    {
        return m_synthetic.m_pModule;
    }
}

mdMethodDef ILCodeVersion::GetMethodDef() const
{
    LIMITED_METHOD_DAC_CONTRACT;
    if (m_storageKind == StorageKind::Explicit)
    {
        return AsNode()->GetMethodDef();
    }
    else
    {
        return m_synthetic.m_methodDef;
    }
}

ReJITID ILCodeVersion::GetVersionId() const
{
    LIMITED_METHOD_DAC_CONTRACT;
    if (m_storageKind == StorageKind::Explicit)
    {
        return AsNode()->GetVersionId();
    }
    else
    {
        return 0;
    }
}

NativeCodeVersionCollection ILCodeVersion::GetNativeCodeVersions(PTR_MethodDesc pClosedMethodDesc) const
{
    LIMITED_METHOD_DAC_CONTRACT;
    return NativeCodeVersionCollection(pClosedMethodDesc, *this);
}

NativeCodeVersion ILCodeVersion::GetActiveNativeCodeVersion(PTR_MethodDesc pClosedMethodDesc) const
{
    LIMITED_METHOD_DAC_CONTRACT;
    _ASSERTE(CodeVersionManager::IsLockOwnedByCurrentThread());

    NativeCodeVersionCollection versions = GetNativeCodeVersions(pClosedMethodDesc);
    for (NativeCodeVersionIterator cur = versions.Begin(), end = versions.End(); cur != end; cur++)
    {
        if (cur->IsActiveChildVersion())
        {
            return *cur;
        }
    }
    return NativeCodeVersion();
}

#if defined(FEATURE_TIERED_COMPILATION) && !defined(DACCESS_COMPILE)
bool ILCodeVersion::HasAnyOptimizedNativeCodeVersion(NativeCodeVersion tier0NativeCodeVersion) const
{
    WRAPPER_NO_CONTRACT;
    _ASSERTE(CodeVersionManager::IsLockOwnedByCurrentThread());
    _ASSERTE(!tier0NativeCodeVersion.IsNull());
    _ASSERTE(tier0NativeCodeVersion.GetILCodeVersion() == *this);
    _ASSERTE(tier0NativeCodeVersion.GetMethodDesc()->IsEligibleForTieredCompilation());
    _ASSERTE(!tier0NativeCodeVersion.IsFinalTier());

    NativeCodeVersionCollection nativeCodeVersions = GetNativeCodeVersions(tier0NativeCodeVersion.GetMethodDesc());
    for (auto itEnd = nativeCodeVersions.End(), it = nativeCodeVersions.Begin(); it != itEnd; ++it)
    {
        NativeCodeVersion nativeCodeVersion = *it;

        // The tier 0 native code version is often the default code version and this is much faster than below
        if (nativeCodeVersion == tier0NativeCodeVersion)
        {
            continue;
        }

        NativeCodeVersion::OptimizationTier optimizationTier = nativeCodeVersion.GetOptimizationTier();
        if (optimizationTier == NativeCodeVersion::OptimizationTier1 ||
            optimizationTier == NativeCodeVersion::OptimizationTierOptimized)
        {
            return true;
        }
    }

    return false;
}
#endif

RejitFlags ILCodeVersion::GetRejitState() const
{
    LIMITED_METHOD_DAC_CONTRACT;
    if (m_storageKind == StorageKind::Explicit)
    {
        return AsNode()->GetRejitState();
    }
    else
    {
        return RejitFlags::kStateActive;
    }
}

BOOL ILCodeVersion::GetEnableReJITCallback() const
{
    LIMITED_METHOD_DAC_CONTRACT;
    if (m_storageKind == StorageKind::Explicit)
    {
        return AsNode()->GetEnableReJITCallback();
    }
    else
    {
        return FALSE;
    }
}

PTR_COR_ILMETHOD ILCodeVersion::GetIL() const
{
    CONTRACTL
    {
        THROWS; //GetILHeader throws
        GC_NOTRIGGER;
        FORBID_FAULT;
        MODE_ANY;
    }
    CONTRACTL_END

    PTR_COR_ILMETHOD pIL = NULL;
    if (m_storageKind == StorageKind::Explicit)
    {
        pIL = AsNode()->GetIL();
    }

    // For the default code version we always fetch the globally stored default IL for a method
    //
    // In the non-default code version we assume NULL is the equivalent of explicitly requesting to
    // re-use the default IL. Ideally there would be no reason to create a new version that re-uses
    // the default IL (just use the default code version for that) but we do it here for compat. We've
    // got some profilers that use ReJIT to create a new code version and then instead of calling
    // ICorProfilerFunctionControl::SetILFunctionBody they call ICorProfilerInfo::SetILFunctionBody.
    // This mutates the default IL so that it is now correct for their new code version. Of course this
    // also overwrote the previous default IL so now the default code version GetIL() is out of sync
    // with the jitted code. In the majority of cases we never re-read the IL after the initial
    // jitting so this issue goes unnoticed.
    //
    // If changing the default IL after it is in use becomes more problematic in the future we would
    // need to add enforcement that prevents profilers from using ICorProfilerInfo::SetILFunctionBody
    // that way + coordinate with them because it is a breaking change for any profiler currently doing it.
    if(pIL == NULL)
    {
        PTR_Module pModule = GetModule();
        PTR_MethodDesc pMethodDesc = dac_cast<PTR_MethodDesc>(pModule->LookupMethodDef(GetMethodDef()));
        if (pMethodDesc != NULL)
        {
            pIL = dac_cast<PTR_COR_ILMETHOD>(pMethodDesc->GetILHeader());
        }
    }

    return pIL;
}

DWORD ILCodeVersion::GetJitFlags() const
{
    LIMITED_METHOD_DAC_CONTRACT;
    if (m_storageKind == StorageKind::Explicit)
    {
        return AsNode()->GetJitFlags();
    }
    else
    {
        return 0;
    }
}

const InstrumentedILOffsetMapping* ILCodeVersion::GetInstrumentedILMap() const
{
    LIMITED_METHOD_DAC_CONTRACT;
    if (m_storageKind == StorageKind::Explicit)
    {
        return AsNode()->GetInstrumentedILMap();
    }
    else
    {
        return NULL;
    }
}

BOOL ILCodeVersion::IsDeoptimized() const
{
    LIMITED_METHOD_DAC_CONTRACT;
    if (m_storageKind == StorageKind::Explicit)
    {
        return AsNode()->IsDeoptimized();
    }
    else
    {
        return FALSE;
    }
}

#ifndef DACCESS_COMPILE
void ILCodeVersion::SetRejitState(RejitFlags newState)
{
    LIMITED_METHOD_CONTRACT;
    AsNode()->SetRejitState(newState);
}

void ILCodeVersion::SetEnableReJITCallback(BOOL state)
{
    LIMITED_METHOD_CONTRACT;
    return AsNode()->SetEnableReJITCallback(state);
}

void ILCodeVersion::SetIL(COR_ILMETHOD* pIL)
{
    LIMITED_METHOD_CONTRACT;
    AsNode()->SetIL(pIL);
}

void ILCodeVersion::SetJitFlags(DWORD flags)
{
    LIMITED_METHOD_CONTRACT;
    AsNode()->SetJitFlags(flags);
}

void ILCodeVersion::SetInstrumentedILMap(SIZE_T cMap, COR_IL_MAP * rgMap)
{
    LIMITED_METHOD_CONTRACT;
    AsNode()->SetInstrumentedILMap(cMap, rgMap);
}

HRESULT ILCodeVersion::AddNativeCodeVersion(
    MethodDesc* pClosedMethodDesc,
    NativeCodeVersion::OptimizationTier optimizationTier,
    NativeCodeVersion* pNativeCodeVersion,
    PatchpointInfo* patchpointInfo,
    unsigned ilOffset
    )
{
    LIMITED_METHOD_CONTRACT;
    CodeVersionManager* pManager = GetModule()->GetCodeVersionManager();
    HRESULT hr = pManager->AddNativeCodeVersion(*this, pClosedMethodDesc, optimizationTier, pNativeCodeVersion, patchpointInfo, ilOffset);
    if (FAILED(hr))
    {
        _ASSERTE(hr == E_OUTOFMEMORY);
        return hr;
    }
    return S_OK;
}

HRESULT ILCodeVersion::GetOrCreateActiveNativeCodeVersion(MethodDesc* pClosedMethodDesc, NativeCodeVersion* pActiveNativeCodeVersion)
{
    LIMITED_METHOD_CONTRACT;
    _ASSERTE(CodeVersionManager::IsLockOwnedByCurrentThread());

    HRESULT hr = S_OK;
    NativeCodeVersion activeNativeChild = GetActiveNativeCodeVersion(pClosedMethodDesc);
    if (activeNativeChild.IsNull())
    {
        NativeCodeVersion::OptimizationTier optimizationTier =
            TieredCompilationManager::GetInitialOptimizationTier(pClosedMethodDesc);
        if (FAILED(hr = AddNativeCodeVersion(pClosedMethodDesc, optimizationTier, &activeNativeChild)))
        {
            _ASSERTE(hr == E_OUTOFMEMORY);
            return hr;
        }
    }
    // The first added child should automatically become active
    _ASSERTE(GetActiveNativeCodeVersion(pClosedMethodDesc) == activeNativeChild);
    *pActiveNativeCodeVersion = activeNativeChild;
    return S_OK;
}

HRESULT ILCodeVersion::SetActiveNativeCodeVersion(NativeCodeVersion activeNativeCodeVersion)
{
    LIMITED_METHOD_CONTRACT;
    HRESULT hr = S_OK;
    MethodDesc* pMethodDesc = activeNativeCodeVersion.GetMethodDesc();
    NativeCodeVersion prevActiveVersion = GetActiveNativeCodeVersion(pMethodDesc);
    if (prevActiveVersion == activeNativeCodeVersion)
    {
        //nothing to do, this version is already active
        return S_OK;
    }

    if (!prevActiveVersion.IsNull())
    {
        prevActiveVersion.SetActiveChildFlag(FALSE);
    }
    activeNativeCodeVersion.SetActiveChildFlag(TRUE);

    // If needed update the published code body for this method
    CodeVersionManager* pCodeVersionManager = GetModule()->GetCodeVersionManager();
    if (pCodeVersionManager->GetActiveILCodeVersion(GetModule(), GetMethodDef()) == *this)
    {
        if (FAILED(hr = pCodeVersionManager->PublishNativeCodeVersion(pMethodDesc, activeNativeCodeVersion)))
        {
            return hr;
        }
    }

    return S_OK;
}

ILCodeVersionNode* ILCodeVersion::AsNode()
{
    LIMITED_METHOD_CONTRACT;
    //This is dangerous - NativeCodeVersion coerces non-explicit versions to NULL but ILCodeVersion assumes the caller
    //will never invoke AsNode() on a non-explicit node. Asserting for now as a minimal fix, but we should revisit this.
    _ASSERTE(m_storageKind == StorageKind::Explicit);
    return m_pVersionNode;
}
#endif //DACCESS_COMPILE

PTR_ILCodeVersionNode ILCodeVersion::AsNode() const
{
    LIMITED_METHOD_DAC_CONTRACT;
    //This is dangerous - NativeCodeVersion coerces non-explicit versions to NULL but ILCodeVersion assumes the caller
    //will never invoke AsNode() on a non-explicit node. Asserting for now as a minimal fix, but we should revisit this.
    _ASSERTE(m_storageKind == StorageKind::Explicit);
    return m_pVersionNode;
}

ILCodeVersionCollection::ILCodeVersionCollection(PTR_Module pModule, mdMethodDef methodDef) :
    m_pModule(pModule),
    m_methodDef(methodDef)
{}

ILCodeVersionIterator ILCodeVersionCollection::Begin()
{
    LIMITED_METHOD_DAC_CONTRACT;
    return ILCodeVersionIterator(this);
}

ILCodeVersionIterator ILCodeVersionCollection::End()
{
    LIMITED_METHOD_DAC_CONTRACT;
    return ILCodeVersionIterator(NULL);
}

ILCodeVersionIterator::ILCodeVersionIterator(const ILCodeVersionIterator & iter) :
    m_stage(iter.m_stage),
    m_cur(iter.m_cur),
    m_pLinkedListCur(iter.m_pLinkedListCur),
    m_pCollection(iter.m_pCollection)
{}

ILCodeVersionIterator::ILCodeVersionIterator(ILCodeVersionCollection* pCollection) :
    m_stage(pCollection != NULL ? IterationStage::Initial : IterationStage::End),
    m_pLinkedListCur(dac_cast<PTR_ILCodeVersionNode>(nullptr)),
    m_pCollection(pCollection)
{
    LIMITED_METHOD_DAC_CONTRACT;
    First();
}

const ILCodeVersion & ILCodeVersionIterator::Get() const
{
    LIMITED_METHOD_DAC_CONTRACT;
    return m_cur;
}

void ILCodeVersionIterator::First()
{
    LIMITED_METHOD_DAC_CONTRACT;
    Next();
}

void ILCodeVersionIterator::Next()
{
    LIMITED_METHOD_DAC_CONTRACT;
    if (m_stage == IterationStage::Initial)
    {
        m_stage = IterationStage::ImplicitCodeVersion;
        m_cur = ILCodeVersion(m_pCollection->m_pModule, m_pCollection->m_methodDef);
        return;
    }
    if (m_stage == IterationStage::ImplicitCodeVersion)
    {
        CodeVersionManager* pCodeVersionManager = m_pCollection->m_pModule->GetCodeVersionManager();
        PTR_ILCodeVersioningState pILCodeVersioningState = pCodeVersionManager->GetILCodeVersioningState(m_pCollection->m_pModule, m_pCollection->m_methodDef);
        if (pILCodeVersioningState != NULL)
        {
            m_pLinkedListCur = pILCodeVersioningState->GetFirstVersionNode();
        }
        m_stage = IterationStage::LinkedList;
        if (m_pLinkedListCur != NULL)
        {
            m_cur = ILCodeVersion(m_pLinkedListCur);
            return;
        }
    }
    if (m_stage == IterationStage::LinkedList)
    {
        if (m_pLinkedListCur != NULL)
        {
            m_pLinkedListCur = m_pLinkedListCur->GetNextILVersionNode();
        }
        if (m_pLinkedListCur != NULL)
        {
            m_cur = ILCodeVersion(m_pLinkedListCur);
            return;
        }
        else
        {
            m_stage = IterationStage::End;
            m_cur = ILCodeVersion();
            return;
        }
    }
}

bool ILCodeVersionIterator::Equal(const ILCodeVersionIterator &i) const
{
    LIMITED_METHOD_DAC_CONTRACT;
    return m_cur == i.m_cur;
}

MethodDescVersioningState::MethodDescVersioningState(PTR_MethodDesc pMethodDesc) :
    m_pMethodDesc(pMethodDesc),
    m_flags(IsDefaultVersionActiveChildFlag),
    m_nextId(1),
    m_pFirstVersionNode(dac_cast<PTR_NativeCodeVersionNode>(nullptr))
{
    LIMITED_METHOD_DAC_CONTRACT;
}

PTR_MethodDesc MethodDescVersioningState::GetMethodDesc() const
{
    LIMITED_METHOD_DAC_CONTRACT;
    return m_pMethodDesc;
}

#ifndef DACCESS_COMPILE
NativeCodeVersionId MethodDescVersioningState::AllocateVersionId()
{
    LIMITED_METHOD_CONTRACT;
    return m_nextId++;
}
#endif

PTR_NativeCodeVersionNode MethodDescVersioningState::GetFirstVersionNode() const
{
    LIMITED_METHOD_DAC_CONTRACT;
    return m_pFirstVersionNode;
}

BOOL MethodDescVersioningState::IsDefaultVersionActiveChild() const
{
    LIMITED_METHOD_DAC_CONTRACT;
    return (m_flags & IsDefaultVersionActiveChildFlag) != 0;
}
#ifndef DACCESS_COMPILE
void MethodDescVersioningState::SetDefaultVersionActiveChildFlag(BOOL isActive)
{
    LIMITED_METHOD_CONTRACT;
    if (isActive)
    {
        m_flags |= IsDefaultVersionActiveChildFlag;
    }
    else
    {
        m_flags &= ~IsDefaultVersionActiveChildFlag;
    }
}

void MethodDescVersioningState::LinkNativeCodeVersionNode(NativeCodeVersionNode* pNativeCodeVersionNode)
{
    LIMITED_METHOD_CONTRACT;
    pNativeCodeVersionNode->m_pNextMethodDescSibling = m_pFirstVersionNode;
    VolatileStore(&m_pFirstVersionNode, pNativeCodeVersionNode);
}
#endif

ILCodeVersioningState::ILCodeVersioningState(PTR_Module pModule, mdMethodDef methodDef) :
    m_activeVersion(ILCodeVersion(pModule,methodDef)),
    m_pFirstVersionNode(dac_cast<PTR_ILCodeVersionNode>(nullptr)),
    m_pModule(pModule),
    m_methodDef(methodDef)
{}


ILCodeVersioningState::Key::Key() :
    m_pModule(dac_cast<PTR_Module>(nullptr)),
    m_methodDef(0)
{}

ILCodeVersioningState::Key::Key(PTR_Module pModule, mdMethodDef methodDef) :
    m_pModule(pModule),
    m_methodDef(methodDef)
{}

size_t ILCodeVersioningState::Key::Hash() const
{
    LIMITED_METHOD_DAC_CONTRACT;
    return (size_t)(dac_cast<TADDR>(m_pModule) ^ m_methodDef);
}

bool ILCodeVersioningState::Key::operator==(const Key & rhs) const
{
    LIMITED_METHOD_DAC_CONTRACT;
    return (m_pModule == rhs.m_pModule) && (m_methodDef == rhs.m_methodDef);
}

ILCodeVersioningState::Key ILCodeVersioningState::GetKey() const
{
    LIMITED_METHOD_DAC_CONTRACT;
    return Key(m_pModule, m_methodDef);
}

ILCodeVersion ILCodeVersioningState::GetActiveVersion() const
{
    LIMITED_METHOD_DAC_CONTRACT;
    return m_activeVersion;
}

PTR_ILCodeVersionNode ILCodeVersioningState::GetFirstVersionNode() const
{
    LIMITED_METHOD_DAC_CONTRACT;
    return m_pFirstVersionNode;
}

#ifndef DACCESS_COMPILE
void ILCodeVersioningState::SetActiveVersion(ILCodeVersion ilActiveCodeVersion)
{
    LIMITED_METHOD_CONTRACT;
    m_activeVersion = ilActiveCodeVersion;
}

void ILCodeVersioningState::LinkILCodeVersionNode(ILCodeVersionNode* pILCodeVersionNode)
{
    LIMITED_METHOD_CONTRACT;
    _ASSERTE(CodeVersionManager::IsLockOwnedByCurrentThread());
    pILCodeVersionNode->SetNextILVersionNode(m_pFirstVersionNode);
    VolatileStore(&m_pFirstVersionNode, pILCodeVersionNode);
}
#endif

#ifndef DACCESS_COMPILE
bool CodeVersionManager::s_initialNativeCodeVersionMayNotBeTheDefaultNativeCodeVersion = false;
#endif

PTR_ILCodeVersioningState CodeVersionManager::GetILCodeVersioningState(PTR_Module pModule, mdMethodDef methodDef) const
{
    LIMITED_METHOD_DAC_CONTRACT;
    // Safe without any locks, because this uses a LookupMap, which is safe for concurrent reads of pre-initialized data
    return pModule->LookupILCodeVersioningState(methodDef);
}

PTR_MethodDescVersioningState CodeVersionManager::GetMethodDescVersioningState(PTR_MethodDesc pClosedMethodDesc) const
{
    LIMITED_METHOD_DAC_CONTRACT;
    return pClosedMethodDesc->GetMethodDescVersionState();
}

SVAL_IMPL_INIT(BOOL, CodeVersionManager, s_HasNonDefaultILVersions, FALSE);

#ifndef DACCESS_COMPILE
HRESULT CodeVersionManager::GetOrCreateILCodeVersioningState(Module* pModule, mdMethodDef methodDef, ILCodeVersioningState** ppILCodeVersioningState)
{
    CONTRACTL
    {
        NOTHROW;
        GC_NOTRIGGER;
        PRECONDITION(IsLockOwnedByCurrentThread());
        PRECONDITION(pModule != NULL);
        PRECONDITION(methodDef != mdTokenNil);
        PRECONDITION(ppILCodeVersioningState != NULL);
    }
    CONTRACTL_END;

    LOG((LF_TIEREDCOMPILATION, LL_INFO100, "CVM::GetOrCreateILCodeVersioningState Module=%p MethodDef=0x%08x\n", pModule, methodDef));

    ILCodeVersioningState* pILCodeVersioningState = pModule->LookupILCodeVersioningState(methodDef);
    if (pILCodeVersioningState == NULL)
    {
        pILCodeVersioningState = new (nothrow) ILCodeVersioningState(pModule, methodDef);
        if (pILCodeVersioningState == NULL)
            return E_OUTOFMEMORY;

        HRESULT hr = S_OK;
        EX_TRY
        {
            pModule->EnsureILCodeVersioningStateCanBeStored(methodDef);
        }
        EX_CATCH_HRESULT(hr);
        if (FAILED(hr))
        {
            delete pILCodeVersioningState;
            return hr;
        }
        pModule->EnsuredStoreILCodeVersioningState(methodDef, pILCodeVersioningState);

        LOG((LF_TIEREDCOMPILATION, LL_INFO100, "CVM::GetOrCreateILCodeVersioningState Created state: %p\n", pILCodeVersioningState));

        // Record that we've created at least one IL version.
        s_HasNonDefaultILVersions = TRUE;
    }
    *ppILCodeVersioningState = pILCodeVersioningState;
    return S_OK;
}

HRESULT CodeVersionManager::GetOrCreateMethodDescVersioningState(MethodDesc* pMethod, MethodDescVersioningState** ppMethodVersioningState)
{
    CONTRACTL
    {
        NOTHROW;
        GC_NOTRIGGER;
        PRECONDITION(pMethod != NULL);
        PRECONDITION(ppMethodVersioningState != NULL);
    }
    CONTRACTL_END;

    HRESULT hr;
    MethodDescVersioningState* pMethodVersioningState = pMethod->GetMethodDescVersionState();
    if (pMethodVersioningState == NULL)
    {
        pMethodVersioningState = new (nothrow) MethodDescVersioningState(pMethod);
        if (pMethodVersioningState == NULL)
            return E_OUTOFMEMORY;

        IfFailRet(pMethod->SetMethodDescVersionState(pMethodVersioningState));
        if (hr == S_FALSE)
            delete pMethodVersioningState;

        pMethodVersioningState = pMethod->GetMethodDescVersionState();
    }
    *ppMethodVersioningState = pMethodVersioningState;
    return S_OK;
}
#endif // DACCESS_COMPILE

BOOL CodeVersionManager::HasNonDefaultILVersions()
{
    LIMITED_METHOD_DAC_CONTRACT;

    //This function is legal to call WITHOUT taking the lock
    //It is used to do a quick check if work might be needed without paying the overhead
    //of acquiring the lock and doing dictionary lookups
    return s_HasNonDefaultILVersions;
}

ILCodeVersionCollection CodeVersionManager::GetILCodeVersions(PTR_MethodDesc pMethod)
{
    LIMITED_METHOD_DAC_CONTRACT;
    return GetILCodeVersions(dac_cast<PTR_Module>(pMethod->GetModule()), pMethod->GetMemberDef());
}

ILCodeVersionCollection CodeVersionManager::GetILCodeVersions(PTR_Module pModule, mdMethodDef methodDef)
{
    LIMITED_METHOD_DAC_CONTRACT;
    return ILCodeVersionCollection(pModule, methodDef);
}

ILCodeVersion CodeVersionManager::GetActiveILCodeVersion(PTR_MethodDesc pMethod)
{
    LIMITED_METHOD_DAC_CONTRACT;
    _ASSERTE(IsLockOwnedByCurrentThread());
    return GetActiveILCodeVersion(dac_cast<PTR_Module>(pMethod->GetModule()), pMethod->GetMemberDef());
}

ILCodeVersion CodeVersionManager::GetActiveILCodeVersion(PTR_Module pModule, mdMethodDef methodDef)
{
    LIMITED_METHOD_DAC_CONTRACT;
    _ASSERTE(IsLockOwnedByCurrentThread());
    ILCodeVersioningState* pILCodeVersioningState = GetILCodeVersioningState(pModule, methodDef);
    if (pILCodeVersioningState == NULL)
    {
        return ILCodeVersion(pModule, methodDef);
    }
    else
    {
        return pILCodeVersioningState->GetActiveVersion();
    }
}

ILCodeVersion CodeVersionManager::GetILCodeVersion(PTR_MethodDesc pMethod, ReJITID rejitId)
{
    LIMITED_METHOD_DAC_CONTRACT;

#ifdef FEATURE_REJIT
    ILCodeVersionCollection collection = GetILCodeVersions(pMethod);
    for (ILCodeVersionIterator cur = collection.Begin(), end = collection.End(); cur != end; cur++)
    {
        if (cur->GetVersionId() == rejitId)
        {
            return *cur;
        }
    }
    return ILCodeVersion();
#else // FEATURE_REJIT
    _ASSERTE(rejitId == 0);
    return ILCodeVersion(dac_cast<PTR_Module>(pMethod->GetModule()), pMethod->GetMemberDef());
#endif // FEATURE_REJIT
}

NativeCodeVersionCollection CodeVersionManager::GetNativeCodeVersions(PTR_MethodDesc pMethod) const
{
    LIMITED_METHOD_DAC_CONTRACT;
    return NativeCodeVersionCollection(pMethod, ILCodeVersion());
}

NativeCodeVersion CodeVersionManager::GetNativeCodeVersion(PTR_MethodDesc pMethod, PCODE codeStartAddress) const
{
    LIMITED_METHOD_DAC_CONTRACT;

    NativeCodeVersionCollection nativeCodeVersions = GetNativeCodeVersions(pMethod);
    for (NativeCodeVersionIterator cur = nativeCodeVersions.Begin(), end = nativeCodeVersions.End(); cur != end; cur++)
    {
        if (cur->GetNativeCode() == codeStartAddress)
        {
            return *cur;
        }
    }
    return NativeCodeVersion();
}

#ifndef DACCESS_COMPILE
HRESULT CodeVersionManager::AddILCodeVersion(Module* pModule, mdMethodDef methodDef, ILCodeVersion* pILCodeVersion, BOOL isDeoptimized)
{
    LIMITED_METHOD_CONTRACT;
    _ASSERTE(IsLockOwnedByCurrentThread());

    ILCodeVersioningState* pILCodeVersioningState;
    HRESULT hr = GetOrCreateILCodeVersioningState(pModule, methodDef, &pILCodeVersioningState);
    if (FAILED(hr))
    {
        _ASSERTE(hr == E_OUTOFMEMORY);
        return hr;
    }

    ILCodeVersionNode* pILCodeVersionNode = new (nothrow) ILCodeVersionNode(pModule, methodDef, InterlockedIncrement(reinterpret_cast<LONG*>(&s_GlobalReJitId)), isDeoptimized);
    if (pILCodeVersionNode == NULL)
    {
        return E_OUTOFMEMORY;
    }
    pILCodeVersioningState->LinkILCodeVersionNode(pILCodeVersionNode);
    *pILCodeVersion = ILCodeVersion(pILCodeVersionNode);
    return S_OK;
}

HRESULT CodeVersionManager::SetActiveILCodeVersions(ILCodeVersion* pActiveVersions, DWORD cActiveVersions, CDynArray<CodePublishError> * pErrors)
{
    // If the IL version is in the shared domain we need to iterate all domains
    // looking for instantiations. The domain iterator lock is bigger than
    // the code version manager lock so we can't do this atomically. In one atomic
    // update the bookkeeping for IL versioning will happen and then in a second
    // update the active native code versions will change and precodes
    // will update.
    //
    // Note: For all domains other than the shared AppDomain we could do this
    // atomically, but for now we use the lowest common denominator for all
    // domains.
    CONTRACTL
    {
        NOTHROW;
        GC_NOTRIGGER;
        MODE_PREEMPTIVE;
        CAN_TAKE_LOCK;
        PRECONDITION(CheckPointer(pActiveVersions));
        PRECONDITION(CheckPointer(pErrors, NULL_OK));
    }
    CONTRACTL_END;
    _ASSERTE(!IsLockOwnedByCurrentThread());
    HRESULT hr = S_OK;

#if DEBUG
    for (DWORD i = 0; i < cActiveVersions; i++)
    {
        ILCodeVersion activeVersion = pActiveVersions[i];
        if (activeVersion.IsNull())
        {
            _ASSERTE(!"The active IL version can't be NULL");
        }
    }
#endif

    MethodDescBackpatchInfoTracker::ConditionalLockHolder slotBackpatchLockHolder;

    // Assume that a new IL code version will be added for a method def, and that an instantiation may not yet have native code
    // for the default native code version
    CodeVersionManager::SetInitialNativeCodeVersionMayNotBeTheDefaultNativeCodeVersion();

    // step 1 - mark the IL versions as being active, this ensures that
    // any new method instantiations added after this point will bind to
    // the correct version
    {
        LockHolder codeVersioningLockHolder;
        for (DWORD i = 0; i < cActiveVersions; i++)
        {
            ILCodeVersion activeVersion = pActiveVersions[i];
            ILCodeVersioningState* pILCodeVersioningState = NULL;
            if (FAILED(hr = GetOrCreateILCodeVersioningState(activeVersion.GetModule(), activeVersion.GetMethodDef(), &pILCodeVersioningState)))
            {
                _ASSERTE(hr == E_OUTOFMEMORY);
                return hr;
            }
            pILCodeVersioningState->SetActiveVersion(activeVersion);
        }
    }

    // step 2 - determine the set of pre-existing method instantiations

    // a parallel array to activeVersions
    // for each ILCodeVersion in activeVersions, this lists the set
    // MethodDescs that will need to be updated
    CDynArray<CDynArray<MethodDesc*>> methodDescsToUpdate;
    CDynArray<CodePublishError> errorRecords;
    for (DWORD i = 0; i < cActiveVersions; i++)
    {
        CDynArray<MethodDesc*>* pMethodDescs = methodDescsToUpdate.Append();
        if (pMethodDescs == NULL)
        {
            return E_OUTOFMEMORY;
        }
        *pMethodDescs = CDynArray<MethodDesc*>();

        MethodDesc* pLoadedMethodDesc = pActiveVersions[i].GetModule()->LookupMethodDef(pActiveVersions[i].GetMethodDef());
        if (FAILED(hr = CodeVersionManager::EnumerateClosedMethodDescs(pLoadedMethodDesc, pMethodDescs, &errorRecords)))
        {
            _ASSERTE(hr == E_OUTOFMEMORY);
            return hr;
        }
    }

    // step 3 - update each pre-existing method instantiation
    {
        LockHolder codeVersioningLockHolder;

        for (DWORD i = 0; i < cActiveVersions; i++)
        {
            // Its possible the active IL version has changed if
            // another caller made an update while this method wasn't
            // holding the lock. We will ensure that we synchronize
            // publishing to whatever version is currently active, even
            // if that isn't the IL version we set above.
            //
            // Note: Although we attempt to handle this case gracefully
            // it isn't recommended for callers to do this. Racing two calls
            // that set the IL version to different results means it will be
            // completely arbitrary which version wins.
            ILCodeVersion requestedActiveILVersion = pActiveVersions[i];
            ILCodeVersion activeILVersion = GetActiveILCodeVersion(requestedActiveILVersion.GetModule(), requestedActiveILVersion.GetMethodDef());

            CDynArray<MethodDesc*> methodDescs = methodDescsToUpdate[i];
            for (int j = 0; j < methodDescs.Count(); j++)
            {
                // Get an the active child code version for this method instantiation (it might be NULL, that is OK)
                NativeCodeVersion activeNativeChild = activeILVersion.GetActiveNativeCodeVersion(methodDescs[j]);

                // Publish that child version, because it is the active native child of the active IL version
                // Failing to publish is non-fatal, but we do record it so the caller is aware
                if (FAILED(hr = PublishNativeCodeVersion(methodDescs[j], activeNativeChild)))
                {
                    if (FAILED(hr = AddCodePublishError(activeILVersion.GetModule(), activeILVersion.GetMethodDef(), methodDescs[j], hr, &errorRecords)))
                    {
                        _ASSERTE(hr == E_OUTOFMEMORY);
                        return hr;
                    }
                }
            }
        }
    }

    return S_OK;
}

HRESULT CodeVersionManager::AddNativeCodeVersion(
    ILCodeVersion ilCodeVersion,
    MethodDesc* pClosedMethodDesc,
    NativeCodeVersion::OptimizationTier optimizationTier,
    NativeCodeVersion* pNativeCodeVersion,
    PatchpointInfo* patchpointInfo,
    unsigned ilOffset)
{
    LIMITED_METHOD_CONTRACT;
    _ASSERTE(IsLockOwnedByCurrentThread());

    MethodDescVersioningState* pMethodVersioningState;
    HRESULT hr = GetOrCreateMethodDescVersioningState(pClosedMethodDesc, &pMethodVersioningState);
    if (FAILED(hr))
    {
        _ASSERTE(hr == E_OUTOFMEMORY);
        return hr;
    }

    NativeCodeVersionId newId = pMethodVersioningState->AllocateVersionId();
    NativeCodeVersionNode* pNativeCodeVersionNode = new (nothrow) NativeCodeVersionNode(newId, pClosedMethodDesc, ilCodeVersion.GetVersionId(), optimizationTier, patchpointInfo, ilOffset);
    if (pNativeCodeVersionNode == NULL)
    {
        return E_OUTOFMEMORY;
    }

    pMethodVersioningState->LinkNativeCodeVersionNode(pNativeCodeVersionNode);

    // the first child added is automatically considered the active one.
    if (ilCodeVersion.GetActiveNativeCodeVersion(pClosedMethodDesc).IsNull())
    {
        pNativeCodeVersionNode->SetActiveChildFlag(TRUE);
        _ASSERTE(!ilCodeVersion.GetActiveNativeCodeVersion(pClosedMethodDesc).IsNull());

        // the new child shouldn't have any native code. If it did we might need to
        // publish that code as part of adding the node which would require callers
        // to pay attention to GC suspension and we'd need to report publishing errors
        // back to them.
        _ASSERTE(pNativeCodeVersionNode->GetNativeCode() == (PCODE)NULL);
    }
    *pNativeCodeVersion = NativeCodeVersion(pNativeCodeVersionNode);
    return S_OK;
}

PCODE CodeVersionManager::PublishVersionableCodeIfNecessary(
    MethodDesc* pMethodDesc,
    CallerGCMode callerGCMode,
    bool *doBackpatchRef,
    bool *doFullBackpatchRef)
{
    STANDARD_VM_CONTRACT;
    _ASSERTE(!IsLockOwnedByCurrentThread());
    _ASSERTE(pMethodDesc->IsVersionable());
    _ASSERTE(doBackpatchRef != nullptr);
    _ASSERTE(*doBackpatchRef);
    _ASSERTE(doFullBackpatchRef != nullptr);
    _ASSERTE(!*doFullBackpatchRef);

    HRESULT hr = S_OK;
    PCODE pCode;
    NativeCodeVersion activeVersion;
    do
    {
        // Try a faster check to see if the default native code version would be the active one. If any method gets a new IL or
        // native code version when the method's default native code version does not have native code, the global flag on
        // CodeVersionManager is set (not a typical case, may be possible with profilers). So, if the flag is not set and the
        // default native code version does not have native code, then it must be the active code version.
        pCode = pMethodDesc->GetNativeCode();
        if (pCode == (PCODE)NULL && !CodeVersionManager::InitialNativeCodeVersionMayNotBeTheDefaultNativeCodeVersion())
        {
            activeVersion = NativeCodeVersion(pMethodDesc);
            break;
        }

        if (!pMethodDesc->IsPointingToPrestub())
        {
            *doFullBackpatchRef = true;
            return (PCODE)NULL;
        }

        LockHolder codeVersioningLockHolder;

        if (SUCCEEDED(hr = GetActiveILCodeVersion(pMethodDesc).GetOrCreateActiveNativeCodeVersion(pMethodDesc, &activeVersion)))
        {
            pCode = activeVersion.GetNativeCode();
            break;
        }

        _ASSERTE(hr == E_OUTOFMEMORY);
        ReportCodePublishError(pMethodDesc, hr);
        *doBackpatchRef = false;
        return pCode != (PCODE)NULL ? pCode : pMethodDesc->PrepareInitialCode(callerGCMode);
    } while (false);

    while (true)
    {
        bool handleCallCountingForFirstCall = false;
        bool handleCallCounting = false;
        bool doPublish = true;
        bool profilerMayHaveActivatedNonDefaultCodeVersion = false;

        // Compile the code if needed
        if (pCode == (PCODE)NULL)
        {
            PrepareCodeConfigBuffer configBuffer(activeVersion);
            PrepareCodeConfig *config = configBuffer.GetConfig();

            // Record the caller's GC mode.
            config->SetCallerGCMode(callerGCMode);
            pCode = pMethodDesc->PrepareCode(config);

        #ifdef FEATURE_CODE_VERSIONING
            if (config->ProfilerMayHaveActivatedNonDefaultCodeVersion())
            {
                profilerMayHaveActivatedNonDefaultCodeVersion = true;
            }
        #endif

            if (config->GeneratedOrLoadedNewCode())
            {
            #ifdef FEATURE_TIERED_COMPILATION
                _ASSERTE(!config->ShouldCountCalls() || pMethodDesc->IsEligibleForTieredCompilation());
                _ASSERTE(!config->ShouldCountCalls() || !activeVersion.IsFinalTier());
                if (config->ShouldCountCalls()) // the generated code was at a tier that is call-counted
                {
                    // This is the first call to a call-counted code version of the method
                    // - It is possible that this is not the first call to the method, for example after the method is called a
                    //   few times, a profiler may activate a new IL code version. When the method is called again, it would
                    //   reach this path. It will initiate the tiering delay, which is appropriate when running new IL for the
                    //   first time in the foreground, as it is similar to the method being called for the first time and would
                    //   have to go through the normal flow of tier transitions again.
                    // - Currently, there is only one call-counted tier in the normal flow of tier transitions for a method. In
                    //   the future there may be more call-counted tiers. Those code versions should be jitted and activated in
                    //   the background and would not reach this path.
                    if (g_pConfig->TieredCompilation_CallCountingDelayMs() != 0)
                    {
                        handleCallCountingForFirstCall = true;
                    }
                    else if (g_pConfig->TieredCompilation_CallCounting())
                    {
                        // The tiering delay is disabled, avoid creating call counting stubs on the first call to every method,
                        // as that is a slower path. Instead, wait for a second call to establish call counting.
                        doPublish = false;
                    }
                }
            #endif
            }
            else
            {
            #ifdef FEATURE_TIERED_COMPILATION
                _ASSERTE(!config->ShouldCountCalls());
            #endif
                // The thread that generated or loaded the new code will publish the code and backpatch if necessary
                doPublish = false;
            }
        }
    #ifdef FEATURE_TIERED_COMPILATION
        else
        {
            handleCallCounting = true;
        }
    #endif

        bool done = false;
        bool createTieringBackgroundWorker = false;
        NativeCodeVersion newActiveVersion;
        do
        {
            // Try a faster check to see if we can avoid checking the currently active code version
            // - For the default code version, if a profiler is attached it may be notified of JIT events and may request rejit
            //   synchronously on the same thread. In that case, for back-compat as described below, the returned code must be for
            //   the rejitted or newer code.
            // - It must be ensured that there are no races that could cause an older entry point to replace a newer entry point.
            //   For non-default code versions, it's necessary to check the currently active code version and publish under the
            //   CodeVersionManager's lock. For default code versions, the entry point is atomically updated and only if it is
            //   pointing to the prestub.
            if (activeVersion.IsDefaultVersion() && !handleCallCounting && !profilerMayHaveActivatedNonDefaultCodeVersion)
            {
                if (doPublish)
                {
                    bool mayHaveEntryPointSlotsToBackpatch2 = pMethodDesc->MayHaveEntryPointSlotsToBackpatch();
                    MethodDescBackpatchInfoTracker::ConditionalLockHolder slotBackpatchLockHolder2(
                        mayHaveEntryPointSlotsToBackpatch2);
                    pMethodDesc->TrySetInitialCodeEntryPointForVersionableMethod(pCode, mayHaveEntryPointSlotsToBackpatch2);
                }
                else
                {
                    *doBackpatchRef = false;
                }

                done = true;
                break;
            }

            bool mayHaveEntryPointSlotsToBackpatch = doPublish && pMethodDesc->MayHaveEntryPointSlotsToBackpatch();
            MethodDescBackpatchInfoTracker::ConditionalLockHolder slotBackpatchLockHolder(mayHaveEntryPointSlotsToBackpatch);
            LockHolder codeVersioningLockHolder;

            hr = GetActiveILCodeVersion(pMethodDesc).GetOrCreateActiveNativeCodeVersion(pMethodDesc, &newActiveVersion);
            if (FAILED(hr))
            {
                break;
            }

            // The common case is that newActiveCode == activeCode, however we did leave the lock so there is
            // possibility that the active version has changed. If it has we need to restart the compilation
            // and publishing process with the new active version instead.
            //
            // In theory it should be legitimate to break out of this loop and run the less recent active version,
            // because ultimately this is a race between one thread that is updating the version and another thread
            // trying to run the current version. However for back-compat with ReJIT we need to guarantee that
            // a versioning update at least as late as the profiler JitCompilationFinished callback wins the race.
            if (newActiveVersion == activeVersion)
            {
                if (doPublish)
                {
                    if (!handleCallCounting)
                    {
                        pMethodDesc->SetCodeEntryPoint(pCode);
                    }
                #ifdef FEATURE_TIERED_COMPILATION
                    else if (
                        !CallCountingManager::SetCodeEntryPoint(activeVersion, pCode, true, &createTieringBackgroundWorker))
                    {
                        _ASSERTE(!g_pConfig->TieredCompilation_UseCallCountingStubs());
                        _ASSERTE(!createTieringBackgroundWorker);
                        *doBackpatchRef = doPublish = false;
                    }
                #endif
                }
                else
                {
                    *doBackpatchRef = false;
                }

                done = true;
            }
        } while (false);

        if (done)
        {
            _ASSERTE(SUCCEEDED(hr));

        #ifdef FEATURE_TIERED_COMPILATION
            if (handleCallCountingForFirstCall)
            {
                _ASSERTE(doPublish);
                _ASSERTE(!handleCallCounting);
                _ASSERTE(!createTieringBackgroundWorker);

                // The code entry point is set before recording the method for call counting to avoid a race. Otherwise, the
                // tiering delay may expire and enable call counting for the method before the entry point is set here, in which
                // case calls to the method would not be counted anymore.
                GetAppDomain()->GetTieredCompilationManager()->HandleCallCountingForFirstCall(pMethodDesc);
            }
            else if (createTieringBackgroundWorker)
            {
                _ASSERTE(doPublish);
                _ASSERTE(handleCallCounting);
                _ASSERTE(!handleCallCountingForFirstCall);
                TieredCompilationManager::CreateBackgroundWorker(); // requires GC_TRIGGERS
            }
        #endif

            return pCode;
        }

        if (FAILED(hr))
        {
            break;
        }

        activeVersion = newActiveVersion;
        pCode = activeVersion.GetNativeCode();
    }

    _ASSERTE(hr == E_OUTOFMEMORY);
    ReportCodePublishError(pMethodDesc, hr);
    *doBackpatchRef = false;
    return pCode;
}

HRESULT CodeVersionManager::PublishNativeCodeVersion(MethodDesc* pMethod, NativeCodeVersion nativeCodeVersion)
{
    CONTRACTL
    {
        NOTHROW;
        GC_NOTRIGGER;
        MODE_ANY;
    }
    CONTRACTL_END;

    _ASSERTE(!pMethod->MayHaveEntryPointSlotsToBackpatch() || MethodDescBackpatchInfoTracker::IsLockOwnedByCurrentThread());
    _ASSERTE(IsLockOwnedByCurrentThread());

    if (!pMethod->IsVersionable())
    {
        _ASSERTE(!"This method doesn't support versioning but was requested to be versioned.");
        return E_FAIL;
    }

    HRESULT hr = S_OK;
    PCODE pCode = nativeCodeVersion.IsNull() ? (PCODE)NULL : nativeCodeVersion.GetNativeCode();
    EX_TRY
    {
        if (pCode == (PCODE)NULL)
        {
            LOG((LF_TIEREDCOMPILATION, LL_INFO100, "CVM::PublishNativeCodeVersion pMethod=%p - Resetting\n", pMethod));
            pMethod->ResetCodeEntryPoint();
        }
        else
        {
            LOG((LF_TIEREDCOMPILATION, LL_INFO100, "CVM::PublishNativeCodeVersion pMethod=%p - Set to ver=%u\n",
                pMethod,
                nativeCodeVersion.GetVersionId()));

        #ifdef FEATURE_TIERED_COMPILATION
            bool wasSet = CallCountingManager::SetCodeEntryPoint(nativeCodeVersion, pCode, false, nullptr);
            _ASSERTE(wasSet);
        #else
            pMethod->SetCodeEntryPoint(pCode);
        #endif
        }
    }
    EX_CATCH_HRESULT(hr);
    return hr;
}

// static
HRESULT CodeVersionManager::EnumerateClosedMethodDescs(
    MethodDesc* pMD,
    CDynArray<MethodDesc*> * pClosedMethodDescs,
    CDynArray<CodePublishError> * pUnsupportedMethodErrors)
{
    CONTRACTL
    {
        NOTHROW;
        GC_NOTRIGGER;
        MODE_PREEMPTIVE;
        CAN_TAKE_LOCK;
        PRECONDITION(CheckPointer(pMD, NULL_OK));
        PRECONDITION(CheckPointer(pClosedMethodDescs));
        PRECONDITION(CheckPointer(pUnsupportedMethodErrors));
    }
    CONTRACTL_END;
    HRESULT hr = S_OK;
    if (pMD == NULL)
    {
        // nothing is loaded yet so we're done for this method.
        return S_OK;
    }

    if (!pMD->HasClassOrMethodInstantiation())
    {
        // We have a JITted non-generic.
        MethodDesc ** ppMD = pClosedMethodDescs->Append();
        if (ppMD == NULL)
        {
            return E_OUTOFMEMORY;
        }
        *ppMD = pMD;

        // not generic, we're done for this method
        return S_OK;
    }

    // Ok, now the case of a generic function (or function on generic class), which
    // is loaded, and may thus have compiled instantiations.
    // It's impossible to get to any other kind of domain from the profiling API
    Module* pModule = pMD->GetModule();
    mdMethodDef methodDef = pMD->GetMemberDef();

    // Module is unshared, so just use the module's domain to find instantiations.
    hr = EnumerateDomainClosedMethodDescs(
        AppDomain::GetCurrentDomain(),
        pModule,
        methodDef,
        pClosedMethodDescs,
        pUnsupportedMethodErrors);

    if (FAILED(hr))
    {
        _ASSERTE(hr == E_OUTOFMEMORY);
        return hr;
    }

    return S_OK;
}

// static
HRESULT CodeVersionManager::EnumerateDomainClosedMethodDescs(
    AppDomain * pAppDomainToSearch,
    Module* pModuleContainingMethodDef,
    mdMethodDef methodDef,
    CDynArray<MethodDesc*> * pClosedMethodDescs,
    CDynArray<CodePublishError> * pUnsupportedMethodErrors)
{
    CONTRACTL
    {
        NOTHROW;
        GC_NOTRIGGER;
        MODE_PREEMPTIVE;
        CAN_TAKE_LOCK;
        PRECONDITION(CheckPointer(pAppDomainToSearch, NULL_OK));
        PRECONDITION(CheckPointer(pModuleContainingMethodDef));
        PRECONDITION(CheckPointer(pClosedMethodDescs));
        PRECONDITION(CheckPointer(pUnsupportedMethodErrors));
    }
    CONTRACTL_END;

    _ASSERTE(methodDef != mdTokenNil);

    HRESULT hr;

    _ASSERTE(AppDomain::GetCurrentDomain() == pAppDomainToSearch);

    // these are the default flags which won't actually be used in shared mode other than
    // asserting they were specified with their default values
    AssemblyIterationFlags assemFlags = (AssemblyIterationFlags)(kIncludeLoaded | kIncludeExecution);
    if (pAppDomainToSearch != NULL)
    {
        assemFlags = (AssemblyIterationFlags)(kIncludeAvailableToProfilers | kIncludeExecution);
    }
    LoadedMethodDescIterator it(
        pAppDomainToSearch,
        pModuleContainingMethodDef,
        methodDef,
        assemFlags);
    CollectibleAssemblyHolder<Assembly *> pAssembly;
    while (it.Next(pAssembly.This()))
    {
        MethodDesc * pLoadedMD = it.Current();

        if (!pLoadedMD->IsVersionable())
        {
            // For compatibility with the rejit APIs we ensure certain errors are detected and reported using their
            // original HRESULTS
            HRESULT errorHR = GetNonVersionableError(pLoadedMD);
            if (FAILED(errorHR))
            {
                if (FAILED(hr = CodeVersionManager::AddCodePublishError(pModuleContainingMethodDef, methodDef, pLoadedMD, CORPROF_E_FUNCTION_IS_COLLECTIBLE, pUnsupportedMethodErrors)))
                {
                    _ASSERTE(hr == E_OUTOFMEMORY);
                    return hr;
                }
            }
            continue;
        }

        MethodDesc ** ppMD = pClosedMethodDescs->Append();
        if (ppMD == NULL)
        {
            return E_OUTOFMEMORY;
        }
        *ppMD = pLoadedMD;
    }
    return S_OK;
}
#endif // DACCESS_COMPILE

#ifndef DACCESS_COMPILE
//static
void CodeVersionManager::OnAppDomainExit(AppDomain * pAppDomain)
{
    LIMITED_METHOD_CONTRACT;
    // This would clean up all the allocations we have done and synchronize with any threads that might
    // still be using the data
    _ASSERTE(!".NET Core shouldn't be doing app domain shutdown - if we start doing so this needs to be implemented");
}
#endif

// Returns true if CodeVersionManager is capable of versioning this method. There may be other reasons that the runtime elects
// not to version a method even if CodeVersionManager could support it. Use the MethodDesc::IsVersionableWith*() accessors to
// get the final determination of versioning support for a given method.
//
//static
bool CodeVersionManager::IsMethodSupported(PTR_MethodDesc pMethodDesc)
{
    WRAPPER_NO_CONTRACT;
    _ASSERTE(pMethodDesc != NULL);

    return
        // CodeVersionManager data structures don't properly handle the lifetime semantics of dynamic code at this point
        !pMethodDesc->IsDynamicMethod() &&

        // CodeVersionManager data structures don't properly handle the lifetime semantics of collectible code at this point
        !pMethodDesc->GetLoaderAllocator()->IsCollectible() &&

        // EnC has its own way of versioning
        !pMethodDesc->InEnCEnabledModule();
}

//---------------------------------------------------------------------------------------
//
// Small helper to determine whether a given (possibly instantiated generic) MethodDesc
// is safe to rejit.
//
// Arguments:
//      pMD - MethodDesc to test
// Return Value:
//      S_OK iff pMD is safe to rejit
//      CORPROF_E_FUNCTION_IS_COLLECTIBLE - function can't be rejitted because it is collectible
//

// static
#ifndef DACCESS_COMPILE
HRESULT CodeVersionManager::GetNonVersionableError(MethodDesc* pMD)
{
    CONTRACTL
    {
        NOTHROW;
        GC_NOTRIGGER;
        CAN_TAKE_LOCK;
        MODE_ANY;
    }
    CONTRACTL_END;

    _ASSERTE(pMD != NULL);

    // Weird, non-user functions were already weeded out in RequestReJIT(), and will
    // also never be passed to us by the prestub worker (for the pre-rejit case).
    _ASSERTE(pMD->IsIL());

    // Any MethodDescs that could be collected are not currently supported.  Although we
    // rule out all Ref.Emit modules in RequestReJIT(), there can still exist types defined
    // in a non-reflection module and instantiated into a collectible assembly
    // (e.g., List<MyCollectibleStruct>).  In the future we may lift this
    // restriction by updating the ReJitManager when the collectible assemblies
    // owning the instantiations get collected.
    if (pMD->GetLoaderAllocator()->IsCollectible())
    {
        return CORPROF_E_FUNCTION_IS_COLLECTIBLE;
    }

    return S_OK;
}
#endif

//---------------------------------------------------------------------------------------
//
// Helper that inits a new CodePublishError and adds it to the pErrors array
//
// Arguments:
//      * pModule - The module in the module/MethodDef identifier pair for the method which
//                  had an error during rejit
//      * methodDef - The MethodDef in the module/MethodDef identifier pair for the method which
//                  had an error during rejit
//      * pMD - If available, the specific method instance which had an error during rejit
//      * hrStatus - HRESULT for the rejit error that occurred
//      * pErrors - the list of error records that this method will append to
//
// Return Value:
//      * S_OK: error was appended
//      * E_OUTOFMEMORY: Not enough memory to create the new error item. The array is unchanged.
//

//static
#ifndef DACCESS_COMPILE
HRESULT CodeVersionManager::AddCodePublishError(Module* pModule, mdMethodDef methodDef, MethodDesc* pMD, HRESULT hrStatus, CDynArray<CodePublishError> * pErrors)
{
    CONTRACTL
    {
        NOTHROW;
        GC_NOTRIGGER;
        MODE_ANY;
    }
    CONTRACTL_END;

    if (pErrors == NULL)
    {
        return S_OK;
    }

    CodePublishError* pError = pErrors->Append();
    if (pError == NULL)
    {
        return E_OUTOFMEMORY;
    }
    pError->pModule = pModule;
    pError->methodDef = methodDef;
    pError->pMethodDesc = pMD;
    pError->hrStatus = hrStatus;
    return S_OK;
}
#endif

#ifndef DACCESS_COMPILE
void CodeVersionManager::ReportCodePublishError(CodePublishError* pErrorRecord)
{
    CONTRACTL
    {
        NOTHROW;
        GC_TRIGGERS;
        CAN_TAKE_LOCK;
        MODE_ANY;
    }
    CONTRACTL_END;

    ReportCodePublishError(pErrorRecord->pModule, pErrorRecord->methodDef, pErrorRecord->pMethodDesc, pErrorRecord->hrStatus);
}

NOINLINE void CodeVersionManager::ReportCodePublishError(MethodDesc* pMD, HRESULT hrStatus)
{
    CONTRACTL
    {
        NOTHROW;
        GC_TRIGGERS;
        CAN_TAKE_LOCK;
        MODE_ANY;
    }
    CONTRACTL_END;

    ReportCodePublishError(pMD->GetModule(), pMD->GetMemberDef(), pMD, hrStatus);
}

void CodeVersionManager::ReportCodePublishError(Module* pModule, mdMethodDef methodDef, MethodDesc* pMD, HRESULT hrStatus)
{
    CONTRACTL
    {
        NOTHROW;
        GC_TRIGGERS;
        CAN_TAKE_LOCK;
        MODE_ANY;
    }
    CONTRACTL_END;

#ifdef FEATURE_REJIT
    BOOL isRejitted = FALSE;
    {
        LockHolder codeVersioningLockHolder;
        isRejitted = !GetActiveILCodeVersion(pModule, methodDef).IsDefaultVersion();
    }

    // this isn't perfect, we might be activating a tiered jitting variation of a rejitted
    // method for example. If it proves to be an issue we can revisit.
    if (isRejitted)
    {
        ReJitManager::ReportReJITError(pModule, methodDef, pMD, hrStatus);
    }
#endif
}
#endif // DACCESS_COMPILE

CrstStatic CodeVersionManager::s_lock;

#ifdef _DEBUG
bool CodeVersionManager::IsLockOwnedByCurrentThread()
{
    WRAPPER_NO_CONTRACT;

#ifndef DACCESS_COMPILE
    return !!s_lock.OwnedByCurrentThread();
#else
    return true;
#endif
}
#endif // _DEBUG

#endif // FEATURE_CODE_VERSIONING