1 /*

     2  * Copyright (c) 2000, Oracle and/or its affiliates. All rights reserved.

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

     4  *

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

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

     7  * published by the Free Software Foundation.

     8  *

     9  * This code is distributed in the hope that it will be useful, but WITHOUT

    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

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

    13  * accompanied this code).

    14  *

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

    16  * 2 along with this work; if not, write to the Free Software Foundation,

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

    18  *

    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    20  * or visit www.oracle.com if you need additional information or have any

    21  * questions.

    22  *

    23  */

    24 

    25 #ifndef _REAPER_

    26 #define _REAPER_

    27 

    28 #include <vector>

    29 #include <windows.h>

    30 

    31 typedef void ReaperCB(void* userData);

    32 

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

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

    35     clean up resources associated with those child processes. */

    36 

    37 class Reaper {

    38 private:

    39   Reaper& operator=(const Reaper&);

    40   Reaper(const Reaper&);

    41 

    42 public:

    43   Reaper(ReaperCB*);

    44   ~Reaper();

    45 

    46   // Start the reaper thread.

    47   bool start();

    48 

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

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

    51   // by at most one thread at a time.

    52   bool stop();

    53 

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

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

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

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

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

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

    60   void registerProcess(HANDLE processHandle, void* userData);

    61 

    62 private:

    63   // For thread safety of register()

    64   CRITICAL_SECTION crit;

    65 

    66   ReaperCB* cb;

    67 

    68   // State variables

    69   volatile bool active;

    70   volatile bool shouldShutDown;

    71 

    72   struct ProcessInfo {

    73     HANDLE handle;

    74     void* userData;

    75   };

    76 

    77   // Bookkeeping

    78   std::vector<ProcessInfo> procInfo;

    79 

    80   // Synchronization between application thread and reaper thread

    81   HANDLE event;

    82 

    83   // Entry point for reaper thread

    84   void reaperThread();

    85 

    86   // Static function which is actual thread entry point

    87   static DWORD WINAPI reaperThreadEntry(LPVOID data);

    88 };

    89 

    90 #endif  // #defined _REAPER_