Keep only base/extractor.[cc|h].

base/thread_pool.h

-// Copyright 2004-2009 Google Inc.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//      http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-// ========================================================================
-
-#ifndef OMAHA_BASE_THREAD_POOL_H_
-#define OMAHA_BASE_THREAD_POOL_H_
-
-#include <windows.h>
-#include "base/basictypes.h"
-#include "omaha/base/scoped_any.h"
-
-namespace omaha {
-
-class UserWorkItem {
- public:
-  UserWorkItem() : shutdown_event_(NULL) {}
-  virtual ~UserWorkItem() {}
-
-  // Template method interface
-  void Process() { DoProcess(); }
-
-  HANDLE shutdown_event() const { return shutdown_event_; }
-  void set_shutdown_event(HANDLE shutdown_event) {
-    shutdown_event_ = shutdown_event;
-  }
-
- private:
-  // Executes the work item.
-  virtual void DoProcess() = 0;
-
-  // It is the job of implementers to watch for the signaling of this event
-  // and shutdown correctly. This event is set when the thread pool is closing.
-  // Do not close this event as is owned by the thread pool.
-  HANDLE shutdown_event_;
-  DISALLOW_EVIL_CONSTRUCTORS(UserWorkItem);
-};
-
-class ThreadPool {
- public:
-  ThreadPool();
-
-  // The destructor might block for 'shutdown_delay'.
-  ~ThreadPool();
-
-  HRESULT Initialize(int shutdown_delay);
-
-  // Returns true if any work items are still in progress.
-  bool HasWorkItems() const { return (0 != work_item_count_); }
-
-  // Adds a work item to the queue. If the add fails the ownership of the
-  // work items remains with the caller.
-  HRESULT QueueUserWorkItem(UserWorkItem* work_item, uint32 flags);
-
- private:
-  // Calls UserWorkItem::Process() in the context of the worker thread.
-  void ProcessWorkItem(UserWorkItem* work_item);
-
-  // This is the thread callback required by the underlying windows API.
-  static DWORD WINAPI ThreadProc(void* context);
-
-  // Approximate number of work items in the pool.
-  volatile LONG work_item_count_;
-
-  // This event signals when the thread pool destructor is in progress.
-  scoped_event shutdown_event_;
-
-  // How many milliseconds to wait for the work items to finish when
-  // the thread pool is shutting down. The shutdown delay resolution is ~10ms.
-  int shutdown_delay_;
-
-  DISALLOW_EVIL_CONSTRUCTORS(ThreadPool);
-};
-
-}  // namespace omaha
-
-#endif  // OMAHA_BASE_THREAD_POOL_H_
-