00001 /*!@file Util/Janitor.H Simple utility class for running a cleanup function during stack unwinding */ 00002 00003 // //////////////////////////////////////////////////////////////////// // 00004 // The iLab Neuromorphic Vision C++ Toolkit - Copyright (C) 2000-2005 // 00005 // by the University of Southern California (USC) and the iLab at USC. // 00006 // See http://iLab.usc.edu for information about this project. // 00007 // //////////////////////////////////////////////////////////////////// // 00008 // Major portions of the iLab Neuromorphic Vision Toolkit are protected // 00009 // under the U.S. patent ``Computation of Intrinsic Perceptual Saliency // 00010 // in Visual Environments, and Applications'' by Christof Koch and // 00011 // Laurent Itti, California Institute of Technology, 2001 (patent // 00012 // pending; application number 09/912,225 filed July 23, 2001; see // 00013 // http://pair.uspto.gov/cgi-bin/final/home.pl for current status). // 00014 // //////////////////////////////////////////////////////////////////// // 00015 // This file is part of the iLab Neuromorphic Vision C++ Toolkit. // 00016 // // 00017 // The iLab Neuromorphic Vision C++ Toolkit is free software; you can // 00018 // redistribute it and/or modify it under the terms of the GNU General // 00019 // Public License as published by the Free Software Foundation; either // 00020 // version 2 of the License, or (at your option) any later version. // 00021 // // 00022 // The iLab Neuromorphic Vision C++ Toolkit is distributed in the hope // 00023 // that it will be useful, but WITHOUT ANY WARRANTY; without even the // 00024 // implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR // 00025 // PURPOSE. See the GNU General Public License for more details. // 00026 // // 00027 // You should have received a copy of the GNU General Public License // 00028 // along with the iLab Neuromorphic Vision C++ Toolkit; if not, write // 00029 // to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, // 00030 // Boston, MA 02111-1307 USA. // 00031 // //////////////////////////////////////////////////////////////////// // 00032 // 00033 // Primary maintainer for this file: Rob Peters <rjpeters at usc dot edu> 00034 // $HeadURL: svn://isvn.usc.edu/software/invt/trunk/saliency/src/Util/Janitor.H $ 00035 // $Id: Janitor.H 7958 2007-02-20 23:30:52Z rjpeters $ 00036 // 00037 00038 #ifndef UTIL_JANITOR_H_DEFINED 00039 #define UTIL_JANITOR_H_DEFINED 00040 00041 /// Simple utility class for running a cleanup function during stack unwinding 00042 /** This is useful in wrapping C APIs where resources are managed with 00043 acquisition and release functions. In that case, you can create a 00044 Janitor<SomeType> with a pointer to the C release function, so 00045 that the release function will be automatically called when the 00046 enclosing scope is exited (whether by function return or by 00047 exception propagation). */ 00048 template <class T> 00049 struct Janitor 00050 { 00051 typedef void (void_func)(void*); 00052 00053 typedef void (free_func)(T, void_func*); 00054 00055 template <class F> 00056 static void typed_freeit(T t, void_func* vf) 00057 { 00058 if (vf != 0 && t != 0) 00059 (*reinterpret_cast<F>(vf))(t); 00060 } 00061 00062 template <class F> 00063 Janitor(T t, F f) 00064 : 00065 it(t), 00066 vfunc(reinterpret_cast<void_func*>(f)), 00067 freeit(&typed_freeit<F>) 00068 {} 00069 00070 ~Janitor() 00071 { 00072 if (freeit != 0 && it != 0) 00073 (*freeit)(it, vfunc); 00074 } 00075 00076 T release() 00077 { 00078 freeit = 0; 00079 return it; 00080 } 00081 00082 T it; 00083 00084 private: 00085 void_func* vfunc; 00086 free_func* freeit; 00087 }; 00088 00089 // ###################################################################### 00090 /* So things look consistent in everyone's emacs... */ 00091 /* Local Variables: */ 00092 /* mode: c++ */ 00093 /* indent-tabs-mode: nil */ 00094 /* End: */ 00095 00096 #endif // UTIL_JANITOR_H_DEFINED
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