libstdc++-v3/src/globals.cc

   1 // Copyright (C) 2001 Free Software Foundation, Inc.
   2 //
   3 // This file is part of the GNU ISO C++ Library.  This library is free
   4 // software; you can redistribute it and/or modify it under the
   5 // terms of the GNU General Public License as published by the
   6 // Free Software Foundation; either version 2, or (at your option)
   7 // any later version.
   8
   9 // This library is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13
  14 // You should have received a copy of the GNU General Public License along
  15 // with this library; see the file COPYING.  If not, write to the Free
  16 // Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
  17 // USA.
  18
  19 // As a special exception, you may use this file as part of a free software
  20 // library without restriction.  Specifically, if other files instantiate
  21 // templates or use macros or inline functions from this file, or you compile
  22 // this file and link it with other files to produce an executable, this
  23 // file does not by itself cause the resulting executable to be covered by
  24 // the GNU General Public License.  This exception does not however
  25 // invalidate any other reasons why the executable file might be covered by
  26 // the GNU General Public License.
  27
  28 #include "bits/c++config.h"
  29 #include "bits/gthr.h"
  30 #include <fstream>
  31 #include <istream>
  32 #include <ostream>
  33
  34 // On AIX, and perhaps other systems, library initialization order is
  35 // not guaranteed.  For example, the static initializers for the main
  36 // program might run before the static initializers for this library.
  37 // That means that we cannot rely on static initialization in the
  38 // library; there is no guarantee that things will get initialized in
  39 // time.  This file contains definitions of all global variables that
  40 // require initialization as arrays of characters.
  41
  42 // Because <iostream> declares the standard streams to be [io]stream
  43 // types instead of say [io]fstream types, it is also necessary to
  44 // allocate the actual file buffers in this file.
  45 namespace std
  46 {
  47   typedef char fake_istream[sizeof(istream)]
  48   __attribute__ ((aligned(__alignof__(istream))));
  49   typedef char fake_ostream[sizeof(ostream)]
  50   __attribute__ ((aligned(__alignof__(ostream))));
  51   fake_istream cin;
  52   fake_ostream cout;
  53   fake_ostream cerr;
  54   fake_ostream clog;
  55
  56   typedef char fake_filebuf[sizeof(filebuf)]
  57   __attribute__ ((aligned(__alignof__(filebuf))));
  58   fake_filebuf buf_cout;
  59   fake_filebuf buf_cin;
  60   fake_filebuf buf_cerr;
  61
  62 #ifdef _GLIBCPP_USE_WCHAR_T
  63   typedef char fake_wistream[sizeof(wistream)]
  64   __attribute__ ((aligned(__alignof__(wistream))));
  65   typedef char fake_wostream[sizeof(wostream)]
  66   __attribute__ ((aligned(__alignof__(wostream))));
  67   fake_wistream wcin;
  68   fake_wostream wcout;
  69   fake_wostream wcerr;
  70   fake_wostream wclog;
  71
  72   typedef char fake_wfilebuf[sizeof(wfilebuf)]
  73   __attribute__ ((aligned(__alignof__(wfilebuf))));
  74   fake_wfilebuf buf_wcout;
  75   fake_wfilebuf buf_wcin;
  76   fake_wfilebuf buf_wcerr;
  77 #endif
  78
  79 // Globals for once-only runtime initialization of mutex objects.  This
  80 // allows static initialization of these objects on systems that need a
  81 // function call to initialize a mutex.  For example, see stl_threads.h.
  82 #if __GTHREADS
  83 #ifdef __GTHREAD_MUTEX_INIT
  84 // This path is not needed since static initialization of mutexs works
  85 // on this platform.
  86 #elif defined(__GTHREAD_MUTEX_INIT_FUNCTION)
  87 __gthread_once_t _GLIBCPP_once = __GTHREAD_ONCE_INIT;
  88 __gthread_mutex_t _GLIBCPP_mutex;
  89 __gthread_mutex_t *_GLIBCPP_mutex_address;
  90
  91 // Once-only initializer function for _GLIBCPP_mutex.
  92 void
  93 _GLIBCPP_mutex_init ()
  94 {
  95   __GTHREAD_MUTEX_INIT_FUNCTION (&_GLIBCPP_mutex);
  96 }
  97 // Once-only initializer function for _GLIBCPP_mutex_address.
  98 void
  99 _GLIBCPP_mutex_address_init ()
 100 {
 101   __GTHREAD_MUTEX_INIT_FUNCTION (_GLIBCPP_mutex_address);
 102 }
 103 #endif
 104 #endif
 105 }