Author: sebor
Date: Mon Mar 31 16:37:16 2008
New Revision: 643210
URL: http://svn.apache.org/viewvc?rev=643210&view=rev
Log:
2008-03-31 Martin Sebor <[EMAIL PROTECTED]>
STDCXX-804
* include/ostream (ostream::_C_opfx): Detect and avoid flushing
streams that are tied together or that share the same buffer to
prevent deadlock or infinite recursion.
Modified:
stdcxx/trunk/include/ostream
Modified: stdcxx/trunk/include/ostream
URL:
http://svn.apache.org/viewvc/stdcxx/trunk/include/ostream?rev=643210&r1=643209&r2=643210&view=diff
==============================================================================
--- stdcxx/trunk/include/ostream (original)
+++ stdcxx/trunk/include/ostream Mon Mar 31 16:37:16 2008
@@ -23,7 +23,7 @@
* implied. See the License for the specific language governing
* permissions and limitations under the License.
*
- * Copyright 1994-2006 Rogue Wave Software.
+ * Copyright 1994-2008 Rogue Wave Software, Inc.
*
**************************************************************************/
@@ -294,12 +294,27 @@
inline basic_ostream<_CharT, _Traits>&
basic_ostream<_CharT, _Traits>::_C_opfx ()
{
- basic_ostream* const __tie = this->tie ();
+ basic_ostream* __tie = this->tie ();
- // flush tied stream only if its buffer is distinct from that
- // of *this for greater efficiency and to to prevent a deadlock
- if (__tie && this->good () && __tie->rdbuf () != this->rdbuf ())
- __tie->flush ();
+ if (__tie && this->good ()) {
+
+ // detect and avoid flushing streams that are tied together
+ // or that share the same buffer to prevent deadlock or
+ // infinite recursion
+ const basic_ostream *__p0, *__p1;
+
+ // traverse the list of tied streams looking for a cycle
+ for (__p0 = this, __p1 = this->tie (); __p0 && __p1;
+ __p0 = __p0->tie (),
+ __p1 = __p1->tie () ? __p1->tie ()->tie () : 0)
+ if (__p0 == __p1 || __p0->rdbuf () == __p1->rdbuf ()) {
+ __tie = 0;
+ break;
+ }
+
+ if (__tie)
+ __tie->flush ();
+ }
if (_C_is_sync ())
_RW::__rw_fflush (_RWSTD_STATIC_CAST (ios_base*, this), 0);
