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diff --git a/sandbox/win/src/win2k_threadpool.h b/sandbox/win/src/win2k_threadpool.h
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+++ b/sandbox/win/src/win2k_threadpool.h
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+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef SANDBOX_SRC_WIN2K_THREADPOOL_H_
+#define SANDBOX_SRC_WIN2K_THREADPOOL_H_
+
+#include <list>
+#include <algorithm>
+#include "sandbox/win/src/crosscall_server.h"
+
+namespace sandbox {
+
+// Win2kThreadPool a simple implementation of a thread provider as required
+// for the sandbox IPC subsystem. See sandbox\crosscall_server.h for the details
+// and requirements of this interface.
+//
+// Implementing the thread provider as a thread pool is desirable in the case
+// of shared memory IPC because it can generate a large number of waitable
+// events: as many as channels. A thread pool does not create a thread per
+// event, instead maintains a few idle threads but can create more if the need
+// arises.
+//
+// This implementation simply thunks to the nice thread pool API of win2k.
+class Win2kThreadPool : public ThreadProvider {
+ public:
+  Win2kThreadPool() {
+    ::InitializeCriticalSection(&lock_);
+  }
+  virtual ~Win2kThreadPool();
+
+  virtual bool RegisterWait(const void* cookie, HANDLE waitable_object,
+                            CrossCallIPCCallback callback,
+                            void* context);
+
+  virtual bool UnRegisterWaits(void* cookie);
+
+  // Returns the total number of wait objects associated with
+  // the thread pool.
+  size_t OutstandingWaits();
+
+ private:
+  // record to keep track of a wait and its associated cookie.
+  struct PoolObject {
+    const void* cookie;
+    HANDLE wait;
+  };
+  // The list of pool wait objects.
+  typedef std::list<PoolObject> PoolObjects;
+  PoolObjects pool_objects_;
+  // This lock protects the list of pool wait objects.
+  CRITICAL_SECTION lock_;
+  DISALLOW_COPY_AND_ASSIGN(Win2kThreadPool);
+};
+
+}  // namespace sandbox
+
+#endif  // SANDBOX_SRC_WIN2K_THREADPOOL_H_