1 files changed, 100 insertions, 0 deletions
diff --git a/src/vm/typeequivalencehash.cpp b/src/vm/typeequivalencehash.cpp
new file mode 100644
index 0000000000..ca2ecfdb2d
--- /dev/null
+++ b/src/vm/typeequivalencehash.cpp
@@ -0,0 +1,100 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+//
+// Hash table associated with each module that records for all types defined in that module the mapping
+// between type name and token (or TypeHandle).
+//
+
+#include "common.h"
+#include "typeequivalencehash.hpp"
+#include "ngenhash.inl"
+
+#ifdef FEATURE_TYPEEQUIVALENCE
+TypeEquivalenceHashTable::EquivalenceMatch TypeEquivalenceHashTable::CheckEquivalence(TypeHandle thA, TypeHandle thB)
+{
+    CONTRACTL
+    {
+        THROWS;
+        GC_TRIGGERS;
+        MODE_ANY;
+    }
+    CONTRACTL_END;
+
+    LookupContext lookupContext;
+    NgenHashValue hash = TypeEquivalenceEntry::HashTypeHandles(thA, thB);
+
+    PTR_TypeEquivalenceEntry search = BaseFindFirstEntryByHash(hash, &lookupContext);
+    while (search != NULL)
+    {
+        if (search->Match(thA, thB))
+        {
+            return search->GetEquivalence() ? Match : NoMatch;
+        }
+
+        search = BaseFindNextEntryByHash(&lookupContext);
+    }
+    return MatchUnknown;
+}
+
+#ifndef DACCESS_COMPILE
+/*static*/
+TypeEquivalenceHashTable *TypeEquivalenceHashTable::Create(AppDomain *pAppDomain, DWORD dwNumBuckets, CrstExplicitInit *pCrst)
+{
+    CONTRACTL
+    {
+        THROWS;
+        GC_TRIGGERS;
+        MODE_ANY;
+        INJECT_FAULT(COMPlusThrowOM(););
+    }
+    CONTRACTL_END;
+
+    AllocMemTracker amt;
+    LoaderHeap *pHeap = pAppDomain->GetLowFrequencyHeap();
+    TypeEquivalenceHashTable *pThis = (TypeEquivalenceHashTable*)amt.Track(pHeap->AllocMem((S_SIZE_T)sizeof(TypeEquivalenceHashTable)));
+
+    // The base class get initialized through chaining of constructors. We allocated the hash instance via the
+    // loader heap instead of new so use an in-place new to call the constructors now.
+    new (pThis) TypeEquivalenceHashTable(pHeap, dwNumBuckets, pCrst);
+    amt.SuppressRelease();
+
+    return pThis;
+}
+
+void TypeEquivalenceHashTable::RecordEquivalence(TypeHandle thA, TypeHandle thB, TypeEquivalenceHashTable::EquivalenceMatch match)
+{
+    CONTRACTL
+    {
+        THROWS;
+        GC_TRIGGERS;
+        MODE_ANY;
+        INJECT_FAULT(COMPlusThrowOM(););
+        PRECONDITION(match != TypeEquivalenceHashTable::MatchUnknown);
+    }
+    CONTRACTL_END;
+
+    CrstHolder ch(m_pHashTableCrst);
+
+    // Was there a race in calculating equivalence and this thread lost?
+    // If so, return
+    EquivalenceMatch checkedMatch = CheckEquivalence(thA, thB);
+    if (checkedMatch != TypeEquivalenceHashTable::MatchUnknown)
+    {
+        _ASSERTE(checkedMatch == match);
+        return;
+    }
+
+    AllocMemTracker amt;
+    PTR_TypeEquivalenceEntry pNewEntry = BaseAllocateEntry(&amt);
+    amt.SuppressRelease();
+
+    pNewEntry->SetData(thA, thB, match == TypeEquivalenceHashTable::Match ? true : false);
+    NgenHashValue hash = TypeEquivalenceEntry::HashTypeHandles(thA, thB);
+
+    BaseInsertEntry(hash, pNewEntry);
+}
+#endif // !DACCESS_COMPILE
+#endif // FEATURE_TYPEEQUIVALENCE
+