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
42namespace __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
82static
83pthread_mutex_t&
84get_mut()
85{
86    static pthread_mutex_t mut = PTHREAD_MUTEX_INITIALIZER;
87    return mut;
88}
89
90ios_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
229