diff --git a/public/ReentrantList.h b/public/ReentrantList.h
new file mode 100644
index 00000000..f9b05e67
--- /dev/null
+++ b/public/ReentrantList.h
@@ -0,0 +1,162 @@
+// vim: set ts=4 sw=4 tw=99 noet :
+// =============================================================================
+// SourceMod
+// Copyright (C) 2004-2008 AlliedModders LLC. All rights reserved.
+// =============================================================================
+//
+// This program is free software; you can redistribute it and/or modify it under
+// the terms of the GNU General Public License, version 3.0, as published by the
+// Free Software Foundation.
+//
+// This program is distributed in the hope that it will be useful, but WITHOUT
+// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+// FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+// details.
+//
+// You should have received a copy of the GNU General Public License along with
+// this program. If not, see .
+//
+// As a special exception, AlliedModders LLC gives you permission to link the
+// code of this program (as well as its derivative works) to "Half-Life 2," the
+// "Source Engine," the "SourcePawn JIT," and any Game MODs that run on software
+// by the Valve Corporation. You must obey the GNU General Public License in
+// all respects for all other code used. Additionally, AlliedModders LLC grants
+// this exception to all derivative works. AlliedModders LLC defines further
+// exceptions, found in LICENSE.txt (as of this writing, version JULY-31-2007),
+// or .
+#ifndef _include_sourcemod_reentrant_iterator_h_
+#define _include_sourcemod_reentrant_iterator_h_
+
+#include
+#include
+
+namespace SourceMod {
+
+// ReentrantList is a wrapper around a LinkedList, with special attention twoard
+// reentrancy. The list may be mutated during iteration as long as its iterator
+// protocol is obeyed: iterators may only be used on the stack in a LIFO manner,
+// and it is illegal to request access to an iterator's item after the list has
+// been mutated.
+//
+// We guard against this using assertions. If an item in a list is removed, and
+// this affects any active iterators, those iterators cannot be used until their
+// next() function is called.
+template
+class ReentrantList : public ke::LinkedList
+{
+ typedef typename ke::LinkedList BaseType;
+ typedef typename ke::LinkedList::iterator BaseTypeIter;
+
+public:
+ ReentrantList(AllocPolicy ap = AllocPolicy())
+ : ke::LinkedList(ap),
+ top_(nullptr)
+ {
+ }
+
+ // Begin and end are disallowed here.
+ void begin() = delete;
+ void end() = delete;
+
+ class iterator
+ {
+ public:
+ iterator(ReentrantList& list)
+ : iterator(&list)
+ {}
+ iterator(ReentrantList* list)
+ : list_(list),
+ prev_(list_->top_),
+ impl_(list->impl_begin()),
+ mutated_(false)
+ {
+ list_->top_ = this;
+ }
+ ~iterator() {
+ assert(list_->top_ == this);
+ list_->top_ = prev_;
+ }
+
+ // Returns true if the underlying iterator mutated during iteration.
+ bool mutated() const {
+ return mutated_;
+ }
+ bool more() {
+ return impl_ != list_->impl_end();
+ }
+ bool done() {
+ return impl_ == list_->impl_end();
+ }
+
+ // Accessors. It is illegal to access the current item if the list has
+ // mutated.
+ const T& operator *() const {
+ assert(!mutated());
+ return *impl_;
+ }
+ T& operator *() {
+ assert(!mutated());
+ return *impl_;
+ }
+ T* operator ->() {
+ assert(!mutated());
+ return &*impl_;
+ }
+ const T* operator ->() const {
+ assert(!mutated());
+ return &*impl_;
+ }
+
+ void next() {
+ if (mutated_) {
+ mutated_ = false;
+ return;
+ }
+ impl_++;
+ }
+
+ void remove() {
+ BaseTypeIter old_impl = impl_;
+
+ impl_ = list_->erase(impl_);
+ mutated_ = true;
+ for (iterator* p = prev_; p; p = p->prev_) {
+ if (p->impl_ == old_impl) {
+ p->impl_ = impl_;
+ p->mutated_ = true;
+ }
+ }
+ }
+
+ private:
+ ReentrantList* list_;
+ iterator* prev_;
+ BaseTypeIter impl_;
+ bool mutated_;
+ };
+
+ // Same protocol as LinkedList::remove, but we use our own iterator.
+ void remove(const T& obj) {
+ for (iterator iter(this); !iter.done(); iter.next()) {
+ if (*iter == obj) {
+ iter.remove();
+ break;
+ }
+ }
+ }
+
+private:
+ BaseTypeIter impl_begin() {
+ return BaseType::begin();
+ }
+ BaseTypeIter impl_end() {
+ return BaseType::end();
+ }
+
+private:
+ iterator* top_;
+};
+
+} // namespace SourceMod
+
+#endif // _include_sourcemod_reentrant_iterator_h_