ios_init.cc
1 // Iostreams base classes -*- C++ -*- 2 3 // Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006 4 // Free Software Foundation, Inc. 5 // 6 // This file is part of the GNU ISO C++ Library. This library is free 7 // software; you can redistribute it and/or modify it under the 8 // terms of the GNU General Public License as published by the 9 // Free Software Foundation; either version 2, or (at your option) 10 // any later version. 11 12 // This library is distributed in the hope that it will be useful, 13 // but WITHOUT ANY WARRANTY; without even the implied warranty of 14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 // GNU General Public License for more details. 16 17 // You should have received a copy of the GNU General Public License along 18 // with this library; see the file COPYING. If not, write to the Free 19 // Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, 20 // USA. 21 22 // As a special exception, you may use this file as part of a free software 23 // library without restriction. Specifically, if other files instantiate 24 // templates or use macros or inline functions from this file, or you compile 25 // this file and link it with other files to produce an executable, this 26 // file does not by itself cause the resulting executable to be covered by 27 // the GNU General Public License. This exception does not however 28 // invalidate any other reasons why the executable file might be covered by 29 // the GNU General Public License. 30 31 // 32 // ISO C++ 14882: 27.4 Iostreams base classes 33 // 34 35 #include <ios> 36 #include <ostream> 37 #include <istream> 38 #include <fstream> 39 #include <ext/stdio_filebuf.h> 40 #include <ext/stdio_sync_filebuf.h> 41 42 namespace __gnu_internal _GLIBCXX_VISIBILITY(hidden) 43 { 44 using namespace __gnu_cxx; 45 46 // Extern declarations for global objects in src/globals.cc. 47 extern stdio_sync_filebuf<char> buf_cout_sync; 48 extern stdio_sync_filebuf<char> buf_cin_sync; 49 extern stdio_sync_filebuf<char> buf_cerr_sync; 50 51 extern stdio_filebuf<char> buf_cout; 52 extern stdio_filebuf<char> buf_cin; 53 extern stdio_filebuf<char> buf_cerr; 54 55 #ifdef _GLIBCXX_USE_WCHAR_T 56 extern stdio_sync_filebuf<wchar_t> buf_wcout_sync; 57 extern stdio_sync_filebuf<wchar_t> buf_wcin_sync; 58 extern stdio_sync_filebuf<wchar_t> buf_wcerr_sync; 59 60 extern stdio_filebuf<wchar_t> buf_wcout; 61 extern stdio_filebuf<wchar_t> buf_wcin; 62 extern stdio_filebuf<wchar_t> buf_wcerr; 63 #endif 64 } // namespace __gnu_internal 65 66 _GLIBCXX_BEGIN_NAMESPACE(std) 67 68 using namespace __gnu_internal; 69 70 extern istream cin; 71 extern ostream cout; 72 extern ostream cerr; 73 extern ostream clog; 74 75 #ifdef _GLIBCXX_USE_WCHAR_T 76 extern wistream wcin; 77 extern wostream wcout; 78 extern wostream wcerr; 79 extern wostream wclog; 80 #endif 81 82 static 83 pthread_mutex_t& 84 get_mut() 85 { 86 static pthread_mutex_t mut = PTHREAD_MUTEX_INITIALIZER; 87 return mut; 88 } 89 90 ios_base::Init::Init() 91 { 92 if (__gnu_cxx::__exchange_and_add_dispatch(&_S_refcount, 0) == 0) 93 { 94 // If _S_refcount looks like 0, we need to lock a mutex 95 pthread_mutex_lock(&get_mut()); 96 // If _S_refcount is still 0, then initialize 97 if (_S_refcount == 0) 98 { 99 try 100 { 101 // Standard streams default to synced with "C" operations. 102 _S_synced_with_stdio = true; 103 104 new (&buf_cout_sync) stdio_sync_filebuf<char>(stdout); 105 new (&buf_cin_sync) stdio_sync_filebuf<char>(stdin); 106 new (&buf_cerr_sync) stdio_sync_filebuf<char>(stderr); 107 108 // The standard streams are constructed once only and never 109 // destroyed. 110 new (&cout) ostream(&buf_cout_sync); 111 new (&cin) istream(&buf_cin_sync); 112 new (&cerr) ostream(&buf_cerr_sync); 113 new (&clog) ostream(&buf_cerr_sync); 114 cin.tie(&cout); 115 cerr.flags(ios_base::unitbuf); 116 // _GLIBCXX_RESOLVE_LIB_DEFECTS 117 // 455. cerr::tie() and wcerr::tie() are overspecified. 118 cerr.tie(&cout); 119 120 #ifdef _GLIBCXX_USE_WCHAR_T 121 new (&buf_wcout_sync) stdio_sync_filebuf<wchar_t>(stdout); 122 new (&buf_wcin_sync) stdio_sync_filebuf<wchar_t>(stdin); 123 new (&buf_wcerr_sync) stdio_sync_filebuf<wchar_t>(stderr); 124 125 new (&wcout) wostream(&buf_wcout_sync); 126 new (&wcin) wistream(&buf_wcin_sync); 127 new (&wcerr) wostream(&buf_wcerr_sync); 128 new (&wclog) wostream(&buf_wcerr_sync); 129 wcin.tie(&wcout); 130 wcerr.flags(ios_base::unitbuf); 131 wcerr.tie(&wcout); 132 #endif 133 134 _S_refcount = 2; 135 } 136 catch (...) 137 { 138 pthread_mutex_unlock(&get_mut()); 139 throw; 140 } 141 } 142 else 143 // Else _S_refcount != 0 which means initialization is complete, else 144 // I couldn't have gotten the mutex. 145 ++_S_refcount; 146 pthread_mutex_unlock(&get_mut()); 147 } 148 else // _S_refcount >= 2 149 __gnu_cxx::__exchange_and_add_dispatch(&_S_refcount, 1); 150 } 151 152 ios_base::Init::~Init() 153 { 154 if (__gnu_cxx::__exchange_and_add_dispatch(&_S_refcount, -1) == 2) 155 { 156 // Catch any exceptions thrown by basic_ostream::flush() 157 try 158 { 159 // Flush standard output streams as required by 27.4.2.1.6 160 cout.flush(); 161 cerr.flush(); 162 clog.flush(); 163 164 #ifdef _GLIBCXX_USE_WCHAR_T 165 wcout.flush(); 166 wcerr.flush(); 167 wclog.flush(); 168 #endif 169 } 170 catch (...) 171 { } 172 } 173 } 174 175 bool 176 ios_base::sync_with_stdio(bool __sync) 177 { 178 // _GLIBCXX_RESOLVE_LIB_DEFECTS 179 // 49. Underspecification of ios_base::sync_with_stdio 180 bool __ret = ios_base::Init::_S_synced_with_stdio; 181 182 // Turn off sync with C FILE* for cin, cout, cerr, clog iff 183 // currently synchronized. 184 if (!__sync && __ret) 185 { 186 // Make sure the standard streams are constructed. 187 ios_base::Init __init; 188 189 ios_base::Init::_S_synced_with_stdio = __sync; 190 191 // Explicitly call dtors to free any memory that is 192 // dynamically allocated by filebuf ctor or member functions, 193 // but don't deallocate all memory by calling operator delete. 194 buf_cout_sync.~stdio_sync_filebuf<char>(); 195 buf_cin_sync.~stdio_sync_filebuf<char>(); 196 buf_cerr_sync.~stdio_sync_filebuf<char>(); 197 198 #ifdef _GLIBCXX_USE_WCHAR_T 199 buf_wcout_sync.~stdio_sync_filebuf<wchar_t>(); 200 buf_wcin_sync.~stdio_sync_filebuf<wchar_t>(); 201 buf_wcerr_sync.~stdio_sync_filebuf<wchar_t>(); 202 #endif 203 204 // Create stream buffers for the standard streams and use 205 // those buffers without destroying and recreating the 206 // streams. 207 new (&buf_cout) stdio_filebuf<char>(stdout, ios_base::out); 208 new (&buf_cin) stdio_filebuf<char>(stdin, ios_base::in); 209 new (&buf_cerr) stdio_filebuf<char>(stderr, ios_base::out); 210 cout.rdbuf(&buf_cout); 211 cin.rdbuf(&buf_cin); 212 cerr.rdbuf(&buf_cerr); 213 clog.rdbuf(&buf_cerr); 214 215 #ifdef _GLIBCXX_USE_WCHAR_T 216 new (&buf_wcout) stdio_filebuf<wchar_t>(stdout, ios_base::out); 217 new (&buf_wcin) stdio_filebuf<wchar_t>(stdin, ios_base::in); 218 new (&buf_wcerr) stdio_filebuf<wchar_t>(stderr, ios_base::out); 219 wcout.rdbuf(&buf_wcout); 220 wcin.rdbuf(&buf_wcin); 221 wcerr.rdbuf(&buf_wcerr); 222 wclog.rdbuf(&buf_wcerr); 223 #endif 224 } 225 return __ret; 226 } 227 228 _GLIBCXX_END_NAMESPACE