/*

 * Copyright 2000 Sun Microsystems, Inc.  All Rights Reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code 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

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 *

 */

#ifndef _REAPER_

#define _REAPER_

#include <vector>

#include <windows.h>

typedef void ReaperCB(void* userData);

/** A Reaper maintains a thread which waits for child processes to

    terminate; upon termination it calls a user-specified ReaperCB to

    clean up resources associated with those child processes. */

class Reaper {

private:

  Reaper& operator=(const Reaper&);

  Reaper(const Reaper&);

public:

  Reaper(ReaperCB*);

  ~Reaper();

  // Start the reaper thread.

  bool start();

  // Stop the reaper thread. This is called automatically in the

  // reaper's destructor. It is not thread safe and should be called

  // by at most one thread at a time.

  bool stop();

  // Register a given child process with the reaper. This should be

  // called by the application's main thread. When that process

  // terminates, the cleanup callback will be called with the

  // specified userData in the context of the reaper thread. Callbacks

  // are guaranteed to be called serially, so they can safely refer to

  // static data as well as the given user data.

  void registerProcess(HANDLE processHandle, void* userData);

private:

  // For thread safety of register()

  CRITICAL_SECTION crit;

  ReaperCB* cb;

  // State variables

  volatile bool active;

  volatile bool shouldShutDown;

  struct ProcessInfo {

    HANDLE handle;

    void* userData;

  };

  // Bookkeeping

  std::vector<ProcessInfo> procInfo;

  // Synchronization between application thread and reaper thread

  HANDLE event;

  // Entry point for reaper thread

  void reaperThread();

  // Static function which is actual thread entry point

  static DWORD WINAPI reaperThreadEntry(LPVOID data);

};

#endif  // #defined _REAPER_