00001 // BESMemoryManager.cc 00002 00003 // This file is part of bes, A C++ back-end server implementation framework 00004 // for the OPeNDAP Data Access Protocol. 00005 00006 // Copyright (c) 2004,2005 University Corporation for Atmospheric Research 00007 // Author: Patrick West <pwest@ucar.edu> and Jose Garcia <jgarcia@ucar.edu> 00008 // 00009 // This library is free software; you can redistribute it and/or 00010 // modify it under the terms of the GNU Lesser General Public 00011 // License as published by the Free Software Foundation; either 00012 // version 2.1 of the License, or (at your option) any later version. 00013 // 00014 // This library is distributed in the hope that it will be useful, 00015 // but WITHOUT ANY WARRANTY; without even the implied warranty of 00016 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 00017 // Lesser General Public License for more details. 00018 // 00019 // You should have received a copy of the GNU Lesser General Public 00020 // License along with this library; if not, write to the Free Software 00021 // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 00022 // 00023 // You can contact University Corporation for Atmospheric Research at 00024 // 3080 Center Green Drive, Boulder, CO 80301 00025 00026 // (c) COPYRIGHT University Corporation for Atmospheric Research 2004-2005 00027 // Please read the full copyright statement in the file COPYRIGHT_UCAR. 00028 // 00029 // Authors: 00030 // pwest Patrick West <pwest@ucar.edu> 00031 // jgarcia Jose Garcia <jgarcia@ucar.edu> 00032 00033 #include <unistd.h> 00034 #include <iostream> 00035 00036 using std::endl ; 00037 using std::set_new_handler ; 00038 00039 #include "BESMemoryManager.h" 00040 00041 #include "BESLog.h" 00042 #include "BESDebug.h" 00043 #include "BESMemoryGlobalArea.h" 00044 00045 BESMemoryGlobalArea* BESMemoryManager::_memory; 00046 bool BESMemoryManager::_storage_used(false); 00047 new_handler BESMemoryManager::_global_handler; 00048 00049 BESMemoryGlobalArea * 00050 BESMemoryManager::initialize_memory_pool() 00051 { 00052 static BESMemoryGlobalArea mem ; 00053 _memory = &mem ; 00054 return _memory ; 00055 } 00056 00057 void 00058 BESMemoryManager::register_global_pool() 00059 { 00060 _global_handler = set_new_handler( BESMemoryManager::swap_memory ) ; 00061 } 00062 00063 void 00064 BESMemoryManager::swap_memory() 00065 { 00066 *(BESLog::TheLog()) << "BESMemoryManager::This is just a simulation, here we tell BES to go to persistence state" << endl; 00067 set_new_handler( BESMemoryManager::release_global_pool ) ; 00068 } 00069 00070 bool 00071 BESMemoryManager::unregister_global_pool() 00072 { 00073 if( check_memory_pool() ) 00074 { 00075 set_new_handler( _global_handler ) ; 00076 return true ; 00077 } else { 00078 return false ; 00079 } 00080 } 00081 00082 bool 00083 BESMemoryManager::check_memory_pool() 00084 { 00085 if( _storage_used ) 00086 { 00087 BESDEBUG( "bes", "BES: global pool is used, trying to get it back..." ) 00088 //Try to regain the memory... 00089 if( _memory->reclaim_memory() ) 00090 { 00091 _storage_used = false ; 00092 BESDEBUG( "bes", "OK" << endl ) 00093 return true ; 00094 } 00095 else 00096 { 00097 BESDEBUG( "bes", "FAILED" << endl ) 00098 return false ; 00099 } 00100 } 00101 return true ; 00102 } 00103 00104 void 00105 BESMemoryManager::release_global_pool() throw (bad_alloc) 00106 { 00107 // This is really the final resource for BES since therefore 00108 // this method must be second level handler. 00109 // It releases enough memory for an exception sequence to be carried. 00110 // Without this pool of memory for emergencies we will get really 00111 // unexpected behavior from the program. 00112 BESDEBUG( "bes", "BES Warning: low in memory, " 00113 << "releasing global memory pool!" << endl ) 00114 *(BESLog::TheLog()) << "BES Warning: low in memory, " 00115 << "releasing global memory pool!" 00116 << endl; 00117 _storage_used = true ; 00118 _memory->release_memory() ; 00119 00120 // Do not let the caller of this memory consume the global pool for 00121 // normal stuff this is an emergency. 00122 set_new_handler( 0 ) ; 00123 throw bad_alloc() ; 00124 } 00125