libstdc++-v3/testsuite/27_io/basic_filebuf/underflow/char/10097.cc

   1 // { dg-require-fork "" }
   2 // { dg-require-mkfifo "" }
   3
   4 // 2001-05-21 Benjamin Kosnik  <bkoz@redhat.com>
   5
   6 // Copyright (C) 2001-2016 Free Software Foundation, Inc.
   7 //
   8 // This file is part of the GNU ISO C++ Library.  This library is free
   9 // software; you can redistribute it and/or modify it under the
  10 // terms of the GNU General Public License as published by the
  11 // Free Software Foundation; either version 3, or (at your option)
  12 // any later version.
  13
  14 // This library is distributed in the hope that it will be useful,
  15 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 // GNU General Public License for more details.
  18
  19 // You should have received a copy of the GNU General Public License along
  20 // with this library; see the file COPYING3.  If not see
  21 // <http://www.gnu.org/licenses/>.
  22
  23 // 27.8.1.4 Overridden virtual functions
  24
  25 #include <fstream>
  26 #include <cstdlib>
  27 #include <unistd.h>
  28 #include <signal.h>
  29 #include <fcntl.h>
  30 #include <sys/types.h>
  31 #include <sys/stat.h>
  32
  33 // No asserts, avoid leaking the semaphores if a VERIFY fails.
  34 #undef _GLIBCXX_ASSERT
  35
  36 #include <testsuite_hooks.h>
  37
  38 class UnderBuf : public std::filebuf
  39 {
  40 public:
  41   int_type
  42   pub_underflow()
  43   { return underflow(); }
  44
  45   std::streamsize
  46   pub_showmanyc()
  47   { return showmanyc(); }
  48 };
  49
  50 // libstdc++/10097
  51 // filebuf::underflow drops characters.
  52 bool test16()
  53 {
  54   using namespace std;
  55   using namespace __gnu_test;
  56   bool test __attribute__((unused)) = true;
  57
  58   const char* name = "tmp_fifo1";
  59
  60   signal(SIGPIPE, SIG_IGN);
  61   unlink(name);
  62
  63   if (0 != mkfifo(name, S_IRWXU))
  64     {
  65       VERIFY( false );
  66     }
  67
  68   semaphore s1, s2;
  69   int fval = fork();
  70   if (fval == -1)
  71     {
  72       unlink(name);
  73       VERIFY( false );
  74     }
  75   else if (fval == 0)
  76     {
  77       filebuf fbout;
  78       fbout.open(name, ios_base::in|ios_base::out);
  79       VERIFY( fbout.is_open() );
  80       fbout.sputn("0123456789", 10);
  81       fbout.pubsync();
  82       s1.wait();
  83       fbout.close();
  84       s2.signal();
  85       exit(0);
  86     }
  87
  88   UnderBuf fb;
  89   fb.open(name, ios_base::in);
  90
  91   fb.sgetc();
  92   streamsize n = fb.pub_showmanyc();
  93
  94   while (n > 0)
  95     {
  96       --n;
  97
  98       UnderBuf::int_type c = fb.pub_underflow();
  99       VERIFY( c != UnderBuf::traits_type::eof() );
 100
 101       fb.sbumpc();
 102     }
 103
 104   fb.close();
 105   s1.signal();
 106   s2.wait();
 107
 108   return test;
 109 }
 110
 111 int main()
 112 {
 113   return !test16();
 114 }