1 files changed, 49 insertions, 0 deletions
diff --git a/src/inc/defaultallocator.h b/src/inc/defaultallocator.h
new file mode 100644
index 0000000000..ee342dff8b
--- /dev/null
+++ b/src/inc/defaultallocator.h
@@ -0,0 +1,49 @@
+// 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.
+
+#ifndef _DEFAULTALLOCATOR_H_
+#define _DEFAULTALLOCATOR_H_
+
+// The "DefaultAllocator" class may be used by classes that wish to
+// provide the flexibility of using an "IAllocator" may avoid writing
+// conditionals at allocation sites about whether a non-default
+// "IAllocator" has been provided: if none is, they can simply set the
+// allocator to DefaultAllocator::Singleton().
+class DefaultAllocator: public IAllocator
+{
+    static DefaultAllocator s_singleton;
+
+public:
+    void* Alloc(size_t sz)
+    {
+        return ::operator new(sz);
+    }
+
+    void* ArrayAlloc(size_t elemSize, size_t numElems)
+    {
+        ClrSafeInt<size_t> safeElemSize(elemSize);
+        ClrSafeInt<size_t> safeNumElems(numElems);
+        ClrSafeInt<size_t> sz = safeElemSize * safeNumElems;
+        if (sz.IsOverflow())
+        {
+            return NULL;
+        }
+        else
+        {
+            return ::operator new(sz.Value());
+        }
+    }
+
+    virtual void Free(void * p)
+    {
+        ::operator delete(p);
+    }
+
+    static DefaultAllocator* Singleton()
+    {
+        return &s_singleton;
+    }
+};
+
+#endif // _DEFAULTALLOCATOR_H_