void
ios_base::Init::_S_ios_create(bool __sync)
{
- int __bufsize = __sync ? 0 : static_cast<int>(BUFSIZ);
+ int __out_bufsize = __sync ? 0 : static_cast<int>(BUFSIZ);
+ int __in_bufsize = __sync ? 1 : static_cast<int>(BUFSIZ);
+
+#if _GLIBCPP_AVOID_FSEEK
+ // Platforms that prefer to avoid fseek() calls on streams only
+ // get their desire when the C++-layer input buffer size is 1.
+ // This hack hurts performance but keeps correctness across
+ // all types of streams that might be attached to (e.g.) cin.
+ __in_bufsize = 1;
+#endif
// NB: The file globals.cc creates the four standard files
// with NULL buffers. At this point, we swap out the dummy NULL
// [io]stream objects and buffers with the real deal.
- new (&buf_cout) filebuf(stdout, ios_base::out, __bufsize);
- new (&buf_cin) filebuf(stdin, ios_base::in, 1);
- new (&buf_cerr) filebuf(stderr, ios_base::out, __bufsize);
+ new (&buf_cout) filebuf(stdout, ios_base::out, __out_bufsize);
+ new (&buf_cin) filebuf(stdin, ios_base::in, __in_bufsize);
+ new (&buf_cerr) filebuf(stderr, ios_base::out, __out_bufsize);
new (&cout) ostream(&buf_cout);
new (&cin) istream(&buf_cin);
new (&cerr) ostream(&buf_cerr);
cerr.flags(ios_base::unitbuf);
#ifdef _GLIBCPP_USE_WCHAR_T
- new (&buf_wcout) wfilebuf(stdout, ios_base::out, __bufsize);
- new (&buf_wcin) wfilebuf(stdin, ios_base::in, 1);
- new (&buf_wcerr) wfilebuf(stderr, ios_base::out, __bufsize);
+ new (&buf_wcout) wfilebuf(stdout, ios_base::out, __out_bufsize);
+ new (&buf_wcin) wfilebuf(stdin, ios_base::in, __in_bufsize);
+ new (&buf_wcerr) wfilebuf(stderr, ios_base::out, __out_bufsize);
new (&wcout) wostream(&buf_wcout);
new (&wcin) wistream(&buf_wcin);
new (&wcerr) wostream(&buf_wcerr);