[Bug libstdc++/12658] New: Thread safety problems in locale::global() and locale::locale()

[Bug libstdc++/12658] New: Thread safety problems in locale::global() and locale::locale()

[peturr02 at ru dot is]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12658

           Summary: Thread safety problems in locale::global() and
                    locale::locale()
           Product: gcc
           Version: 3.4
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: libstdc++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: peturr02 at ru dot is
                CC: gcc-bugs at gcc dot gnu dot org
 GCC build triplet: i686-pc-linux-gnu
  GCC host triplet: i686-pc-linux-gnu
GCC target triplet: i686-pc-linux-gnu

1)
locale::global(const locale&) is defined so:

  locale
  locale::global(const locale& __other)
  {
    _S_initialize();

    // XXX MT
    _Impl* __old = _S_global;
    __other._M_impl->_M_add_reference();
    _S_global = __other._M_impl; 
    if (_S_global->_M_check_same_name() 
        && (std::strcmp(_S_global->_M_names[0], "*") != 0))
      setlocale(LC_ALL, __other.name().c_str());

    // Reference count sanity check: one reference removed for the
    // subsition of __other locale, one added by return-by-value. Net
    // difference: zero. When the returned locale object's destrutor
    // is called, then the reference count is decremented and possibly
    // destroyed.
    return locale(__old);
  }

If two threads run locale::global() at the same time, such that:
1) thread 1 begins and executes
      _Impl* __old = _S_global;
and then yields.
2) thread 2 runs locale::global() completely.
3) thread 1 resumes executions and completes.

Then the reference count of __old is decremented twice, although _S_global
only holds 1 reference. To compensate, the reference count of the locale
assigned to _S_global in thread 2 is incremented, but no reference to it
is stored so is leaked.

2)
locale::locale is defined so:

  locale::locale() throw()
  { 
    _S_initialize(); 
    (_M_impl = _S_global)->_M_add_reference(); 
  }

If
1) thread 1 runs locale::locale() and yields after executing
_M_impl = _S_global but before calling _M_add_reference(), and
the reference count of _S_global is 1.
2) thread 2 runs locale::global() completely and decrements the
reference count of _S_global.
3) thread 1 resumes execution and calls _M_impl->_M_add_reference()

The last reference to _S_global is removed in 2), so
_M_add_reference() in 3) is called on an object that has already been
deleted.

[Bug libstdc++/12658] Thread safety problems in locale::global() and locale::locale()

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2003-11-28 08:30 -------
Confirmed (should be using the atomic versions or a lock).

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
   Last reconfirmed|0000-00-00 00:00:00         |2003-11-28 08:30:55
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12658

[Bug libstdc++/12658] Thread safety problems in locale::global() and locale::locale()

[paolo at gcc dot gnu dot org]

------- Additional Comments From paolo at gcc dot gnu dot org  2003-11-28 12:43 -------
Trying to fix it...

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |paolo at gcc dot gnu dot org
                   |dot org                     |
             Status|NEW                         |ASSIGNED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12658

[Bug libstdc++/12658] Thread safety problems in locale::global() and locale::locale()

[paolo at gcc dot gnu dot org]

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------- Additional Comments From paolo at gcc dot gnu dot org  2003-11-29 11:02 -------
Hi Pétur,

what about the attached? I'm not a MT expert, but naively appears to answer your
concerns...

Paolo.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12658

[Bug libstdc++/12658] Thread safety problems in locale::global() and locale::locale()

[paolo at gcc dot gnu dot org]

------- Additional Comments From paolo at gcc dot gnu dot org  2003-11-29 11:33 -------
... forget about the locale::global part: I have to think a little more about it.

Paolo.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12658

[Bug libstdc++/12658] Thread safety problems in locale::global() and locale::locale()

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2003-11-30 08:18 -------
To me a MT person but not really knowing the code that well, this looks better.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |3.4


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12658

[Bug libstdc++/12658] Thread safety problems in locale::global() and locale::locale()

[Hans dot Heukenkamp at fidaso dot de]

------- Additional Comments From Hans dot Heukenkamp at fidaso dot de  2003-12-11 10:08 -------
I did apply the tentative patch 12658 to the current 3.4 snapshot and tested
on a i386 SMP machine. It does not solve the problem.
I doubt in general that any reference counting approach ever gets thread safe.

H.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12658

[Bug libstdc++/12658] Thread safety problems in locale::global() and locale::locale()

[bkoz at gcc dot gnu dot org]

------- Additional Comments From bkoz at gcc dot gnu dot org  2003-12-13 06:35 -------

Well......... something like this will work. It's modeled off of the glibc
setlocale bits, and I think it will work. 

Thoughts?

2003-12-13  Benjamin Kosnik  <bkoz@redhat.com>

	PR libstdc++/12658
	* include/Makefile.am (bits_headers): Add concurrence.h.
	* include/Makefile.in: Regenerated.
	* include/bits/concurrence.h: New.
	* src/locale_init.cc: Use it.
	(locale::locale): Lock critical regions.
	(locale::global): Same.
  
Index: include/Makefile.am
===================================================================
RCS file: /cvs/gcc/gcc/libstdc++-v3/include/Makefile.am,v
retrieving revision 1.72
diff -c -p -r1.72 Makefile.am
*** include/Makefile.am	11 Nov 2003 20:09:07 -0000	1.72
--- include/Makefile.am	13 Dec 2003 06:32:27 -0000
*************** bits_headers = \
*** 101,106 ****
--- 101,107 ----
  	${bits_srcdir}/char_traits.h \
  	${bits_srcdir}/codecvt.h \
  	${bits_srcdir}/concept_check.h \
+ 	${bits_srcdir}/concurrence.h \
  	${bits_srcdir}/cpp_type_traits.h \
  	${bits_srcdir}/demangle.h \
  	${bits_srcdir}/deque.tcc \
Index: include/bits/concurrence.h
===================================================================
RCS file: include/bits/concurrence.h
diff -N include/bits/concurrence.h
*** /dev/null	1 Jan 1970 00:00:00 -0000
--- include/bits/concurrence.h	13 Dec 2003 06:32:27 -0000
***************
*** 0 ****
--- 1,54 ----
+ // Support for concurrent programing -*- C++ -*-
+ 
+ // Copyright (C) 2003
+ // Free Software Foundation, Inc.
+ //
+ // This file is part of the GNU ISO C++ Library.  This library is free
+ // software; you can redistribute it and/or modify it under the
+ // terms of the GNU General Public License as published by the
+ // Free Software Foundation; either version 2, or (at your option)
+ // any later version.
+ 
+ // This library is distributed in the hope that it will be useful,
+ // but WITHOUT ANY WARRANTY; without even the implied warranty of
+ // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ // GNU General Public License for more details.
+ 
+ // You should have received a copy of the GNU General Public License along
+ // with this library; see the file COPYING.  If not, write to the Free
+ // Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
+ // USA.
+ 
+ // As a special exception, you may use this file as part of a free software
+ // library without restriction.  Specifically, if other files instantiate
+ // templates or use macros or inline functions from this file, or you compile
+ // this file and link it with other files to produce an executable, this
+ // file does not by itself cause the resulting executable to be covered by
+ // the GNU General Public License.  This exception does not however
+ // invalidate any other reasons why the executable file might be covered by
+ // the GNU General Public License.
+  
+ #ifndef _CONCURRENCE
+ #define _CONCURRENCE 1
+ 
+ // GCC's thread abstraction layer
+ #include "bits/gthr.h"
+ 
+ #if __GTHREADS
+ # ifdef __GTHREAD_MUTEX_INIT
+ #  define __glibcxx_mutex_define_initialized(NAME) \
+ __gthread_mutex_t NAME = __GTHREAD_MUTEX_INIT
+ # else
+ #  define __glibcxx_mutex_define_initialized(NAME) \
+ __gthread_mutex_t NAME; \
+ __GTHREAD_MUTEX_INIT_FUNCTION(&NAME)
+ # endif
+ # define __glibcxx_mutex_lock(LOCK) __gthread_mutex_lock(&LOCK)
+ # define __glibcxx_mutex_unlock(LOCK) __gthread_mutex_unlock(&LOCK)
+ #else
+ # define __glibcxx_mutex_define_initialized(NAME)
+ # define __glibcxx_mutex_lock(LOCK) 
+ # define __glibcxx_mutex_unlock(LOCK) 
+ #endif
+ 
+ #endif
Index: src/locale_init.cc
===================================================================
RCS file: /cvs/gcc/gcc/libstdc++-v3/src/locale_init.cc,v
retrieving revision 1.3
diff -c -p -r1.3 locale_init.cc
*** src/locale_init.cc	24 Nov 2003 17:24:40 -0000	1.3
--- src/locale_init.cc	13 Dec 2003 06:32:27 -0000
***************
*** 33,38 ****
--- 33,39 ----
  #include <cwctype>     // For towupper, etc.
  #include <locale>
  #include <bits/atomicity.h>
+ #include <bits/concurrence.h>
  
  namespace __gnu_cxx
  {
*************** namespace std 
*** 96,116 ****
    locale::locale() throw()
    { 
      _S_initialize(); 
!     (_M_impl = _S_global)->_M_add_reference(); 
    }
  
    locale
    locale::global(const locale& __other)
    {
      _S_initialize();
! 
!     // XXX MT
      _Impl* __old = _S_global;
      __other._M_impl->_M_add_reference();
      _S_global = __other._M_impl; 
      if (_S_global->_M_check_same_name() 
  	&& (std::strcmp(_S_global->_M_names[0], "*") != 0))
        setlocale(LC_ALL, __other.name().c_str());
  
      // Reference count sanity check: one reference removed for the
      // subsition of __other locale, one added by return-by-value. Net
--- 97,121 ----
    locale::locale() throw()
    { 
      _S_initialize(); 
!     __glibcxx_mutex_define_initialized(lock);
!     __glibcxx_mutex_lock(lock);
!     (_M_impl = _S_global)->_M_add_reference();
!     __glibcxx_mutex_unlock(lock);
    }
  
    locale
    locale::global(const locale& __other)
    {
      _S_initialize();
!     __glibcxx_mutex_define_initialized(lock);
!     __glibcxx_mutex_lock(lock);
      _Impl* __old = _S_global;
      __other._M_impl->_M_add_reference();
      _S_global = __other._M_impl; 
      if (_S_global->_M_check_same_name() 
  	&& (std::strcmp(_S_global->_M_names[0], "*") != 0))
        setlocale(LC_ALL, __other.name().c_str());
+     __glibcxx_mutex_unlock(lock);
  
      // Reference count sanity check: one reference removed for the
      // subsition of __other locale, one added by return-by-value. Net


-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |bkoz at redhat dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12658

[Bug libstdc++/12658] Thread safety problems in locale::global() and locale::locale()

[bkoz at gcc dot gnu dot org]

------- Additional Comments From bkoz at gcc dot gnu dot org  2003-12-13 06:44 -------

PS there needs to be/should be a threads testcase for this. any takers?

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12658

[Bug libstdc++/12658] Thread safety problems in locale::global() and locale::locale()

[rittle at latour dot rsch dot comm dot mot dot com]

------- Additional Comments From rittle at latour dot rsch dot comm dot mot dot com  2003-12-13 07:12 -------
Subject: Re:  Thread safety problems in locale::global() and
	locale::locale()


>------- Additional Comments From bkoz at gcc dot gnu dot org  2003-12-13

>Well......... something like this will work. It's modeled off of the glibc
>setlocale bits, and I think it will work. 

>Thoughts?

>2003-12-13  Benjamin Kosnik  <bkoz@redhat.com>
>
>	PR libstdc++/12658
>	* include/Makefile.am (bits_headers): Add concurrence.h.
>	* include/Makefile.in: Regenerated.
>	* include/bits/concurrence.h: New.
>	* src/locale_init.cc: Use it.
>	(locale::locale): Lock critical regions.
>	(locale::global): Same.

It seems odd to wrap atomic updates with a mutex but it looks OK...  I
must commend the improvement of adding bits/concurrence.h instead of
continuing the ad hoc style which is scattered about. - Loren


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12658

[Bug libstdc++/12658] Thread safety problems in locale::global() and locale::locale()

[pcarlini at unitus dot it]

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------- Additional Comments From pcarlini at unitus dot it  2003-12-13 08:55 -------
Subject: Re:  Thread safety problems in locale::global()
 and locale::locale()

bkoz at gcc dot gnu dot org wrote:

>------- Additional Comments From bkoz at gcc dot gnu dot org  2003-12-13 06:35 -------
>
>Well......... something like this will work. It's modeled off of the glibc
>setlocale bits, and I think it will work. 
>
>Thoughts?
>  
>
Probably, for locale::global() a lock is really needed, I agree with you.
However, for this

>    locale::locale() throw()
>    { 
>      _S_initialize(); 
>!     (_M_impl = _S_global)->_M_add_reference(); 
>    }
>  
>
Are you really sure that the trivial rearrangement that I proposed 
doesn't suffice?
It appears to answer Pétur's analysis...

Paolo.



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12658

[Bug libstdc++/12658] Thread safety problems in locale::global() and locale::locale()

[bkoz at redhat dot com]

------- Additional Comments From bkoz at redhat dot com  2003-12-13 18:38 -------
Subject: Re:  Thread safety problems in
 locale::global() and locale::locale()


>It seems odd to wrap atomic updates with a mutex but it looks OK... 

Yeah, for locale::locale()? For locale::global it looks less strange, I
think. Sadly, I think it is necessary for locale::locale(), as
assignment + atomic update is not, in combination, atomic... I suppose I
could split that into two lines to clarify.

>I must commend the improvement of adding bits/concurrence.h instead of
>continuing the ad hoc style which is scattered about. - Loren

Well.........

\o.o/

You know my feelings about stl_thread.h.... I was just testing the water
here, to see your reaction. If this is ok then I think I'm going to go
through and consolidate, and try to get rid of the _GTHREADS bits that
have been multiplying in the codebase. Thus, the placement of
bits/concurrence.h as a public header.

That would mean adding similar bits for _gthread_once, usage of which
has multiplied as of late, but it seems very doable. That's a later
patch, however...

Thanks,

benjamin


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12658

[Bug libstdc++/12658] Thread safety problems in locale::global() and locale::locale()

[bkoz at gcc dot gnu dot org]

------- Additional Comments From bkoz at gcc dot gnu dot org  2003-12-13 18:44 -------

Paolo, my bad. I'm sorry.

You are correct. I think just splitting locale::locale() up into:

+    _S_initialize();
+    _S_global->_M_add_reference();
+    _M_impl = _S_global;
 
Will be sufficient, without the heavyweight locks, which is good. Loren, isn't
this correct? This would solve your comment as well.

-benjamin

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12658

[Bug libstdc++/12658] Thread safety problems in locale::global() and locale::locale()

[peturr02 at ru dot is]

------- Additional Comments From peturr02 at ru dot is  2003-12-15 08:14 -------
>+    _S_initialize();
>+    _S_global->_M_add_reference();
>+    _M_impl = _S_global;

This still looks wrong. Consider if one thread runs locale::locale() and
yields after _S_global->_M_add_reference(); Another thread then runs
locale::global() from start to finish. The second thread then completes
locale::locale(). In that case locale::locale() increases the reference
count of the old global locale, but keeps a pointer to the new global locale.
The old global locale gets leaked, and the new global locale will be deleted
while there are still pointers to it.



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12658

[Bug libstdc++/12658] Thread safety problems in locale::global() and locale::locale()

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2003-12-15 21:08 -------
Subject: Bug 12658

CVSROOT:	/cvs/gcc
Module name:	gcc
Changes by:	bkoz@gcc.gnu.org	2003-12-15 21:08:03

Modified files:
	libstdc++-v3   : ChangeLog 
	libstdc++-v3/include: Makefile.am Makefile.in 
	libstdc++-v3/src: locale_init.cc 
Added files:
	libstdc++-v3/include/bits: concurrence.h 

Log message:
	2003-12-15  Benjamin Kosnik  <bkoz@redhat.com>
	
	PR libstdc++/12658
	* include/Makefile.am (bits_headers): Add concurrence.h.
	* include/Makefile.in: Regenerated.
	* include/bits/concurrence.h: New.
	* src/locale_init.cc: Use it.
	(locale::locale): Lock critical regions.
	(locale::global): Same.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/ChangeLog.diff?cvsroot=gcc&r1=1.2158&r2=1.2159
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/include/Makefile.am.diff?cvsroot=gcc&r1=1.72&r2=1.73
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/include/Makefile.in.diff?cvsroot=gcc&r1=1.92&r2=1.93
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/include/bits/concurrence.h.diff?cvsroot=gcc&r1=NONE&r2=1.1
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/src/locale_init.cc.diff?cvsroot=gcc&r1=1.4&r2=1.5



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12658

[Bug libstdc++/12658] Thread safety problems in locale::global() and locale::locale()

[paolo at gcc dot gnu dot org]

------- Additional Comments From paolo at gcc dot gnu dot org  2003-12-18 08:28 -------
Actually took care of it.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|paolo at gcc dot gnu dot org|bkoz at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12658

[Bug libstdc++/12658] Thread safety problems in locale::global() and locale::locale()

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2003-12-18 08:30 -------
Fixed in 3.4.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|                            |FIXED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12658

[Bug libstdc++/12658] Thread safety problems in locale::global() and locale::locale()

[peturr02 at ru dot is]

------- Additional Comments From peturr02 at ru dot is  2004-01-07 11:27 -------
There is a problem with the patch:

http://gcc.gnu.org/ml/libstdc++/2004-01/msg00051.html


-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|RESOLVED                    |REOPENED
         Resolution|FIXED                       |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12658

[Bug libstdc++/12658] Thread safety problems in locale::global() and locale::locale()

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2004-01-07 17:40 -------
Subject: Bug 12658

CVSROOT:	/cvs/gcc
Module name:	gcc
Changes by:	ljrittle@gcc.gnu.org	2004-01-07 17:40:46

Modified files:
	libstdc++-v3   : ChangeLog 
	libstdc++-v3/src: locale_init.cc 

Log message:
	(re-open) PR libstdc++/12658
	* src/locale_init.cc (locale::locale): Remove ill-scoped mutex.
	(locale::global): Likewise.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/ChangeLog.diff?cvsroot=gcc&r1=1.2200&r2=1.2201
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/src/locale_init.cc.diff?cvsroot=gcc&r1=1.5&r2=1.6



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12658

[Bug libstdc++/12658] Thread safety problems in locale::global() and locale::locale()

[pinskia at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|REOPENED                    |ASSIGNED
   Target Milestone|3.4.0                       |---


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12658

[Bug libstdc++/12658] Thread safety problems in locale::global() and locale::locale()

[bkoz at gcc dot gnu dot org]

------- Additional Comments From bkoz at gcc dot gnu dot org  2004-01-08 18:37 -------

Confirmed. Well, back to the drawing board with this one.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12658

[Bug libstdc++/12658] Thread safety problems in locale::global() and locale::locale()

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2004-03-07 01:32 -------
Subject: Bug 12658

CVSROOT:	/cvs/gcc
Module name:	gcc
Changes by:	bkoz@gcc.gnu.org	2004-03-07 01:32:43

Modified files:
	libstdc++-v3   : ChangeLog 
	libstdc++-v3/config: linker-map.gnu 
	libstdc++-v3/config/cpu/generic: atomicity.h 
	libstdc++-v3/config/cpu/hppa: atomicity.h 
	libstdc++-v3/config/os/hpux: os_defines.h 
	libstdc++-v3/include/bits: concurrence.h 
	libstdc++-v3/include/ext: mt_allocator.h 
	libstdc++-v3/src: locale_init.cc misc-inst.cc 

Log message:
	2004-03-06  Benjamin Kosnik  <bkoz@redhat.com>
	
	PR libstdc++/12658
	* src/locale_init.cc (locale::locale): Lock critical regions with
	external mutexes.
	(locale::global): Same.
	* include/bits/concurrence.h (__glibcxx_mutex_define_initialized):
	Add in once bits for cases without __GTHREAD_MUTEX_INIT.
	(__glibcxx_mutex_lock): Same.
	
	* config/cpu/generic/atomicity.h: Remove
	_GLIBCXX_NEED_GENERIC_MUTEX, use concurrence.h.
	* src/misc-inst.cc: Move all locking bits out of this file.
	
	* config/os/hpux/os_defines.h: Remove _GLIBCXX_INST_ATOMICITY_LOCK.
	* src/misc-inst.cc: Same.
	* config/cpu/hppa/atomicity.h: Same.
	
	* config/linker-map.gnu: Remove types in the signature of atomic
	exports, as they may vary.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/ChangeLog.diff?cvsroot=gcc&r1=1.2383&r2=1.2384
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/config/linker-map.gnu.diff?cvsroot=gcc&r1=1.57&r2=1.58
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/config/cpu/generic/atomicity.h.diff?cvsroot=gcc&r1=1.8&r2=1.9
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/config/cpu/hppa/atomicity.h.diff?cvsroot=gcc&r1=1.8&r2=1.9
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/config/os/hpux/os_defines.h.diff?cvsroot=gcc&r1=1.10&r2=1.11
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/include/bits/concurrence.h.diff?cvsroot=gcc&r1=1.2&r2=1.3
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/include/ext/mt_allocator.h.diff?cvsroot=gcc&r1=1.17&r2=1.18
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/src/locale_init.cc.diff?cvsroot=gcc&r1=1.9&r2=1.10
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/src/misc-inst.cc.diff?cvsroot=gcc&r1=1.26&r2=1.27



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12658

[Bug libstdc++/12658] Thread safety problems in locale::global() and locale::locale()

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2004-03-08 22:11 -------
Subject: Bug 12658

CVSROOT:	/cvs/gcc
Module name:	gcc
Changes by:	bkoz@gcc.gnu.org	2004-03-08 22:11:48

Modified files:
	libstdc++-v3   : ChangeLog 
Added files:
	libstdc++-v3/testsuite/22_locale/locale/cons: 12658_thread.cc 

Log message:
	2004-03-08  Petur Runolfsson  <peturr02@ru.is>
	
	PR libstdc++/12658
	* testsuite/22_locale/locale/cons/12658_thread.cc: New.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/ChangeLog.diff?cvsroot=gcc&r1=1.2388&r2=1.2389
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/testsuite/22_locale/locale/cons/12658_thread.cc.diff?cvsroot=gcc&r1=NONE&r2=1.1



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12658

[Bug libstdc++/12658] Thread safety problems in locale::global() and locale::locale()

[bkoz at gcc dot gnu dot org]

------- Additional Comments From bkoz at gcc dot gnu dot org  2004-03-11 17:40 -------

This fix is confirmed, and the new fix didn't kill BSD4.

-benjamin

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|                            |FIXED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12658

[Bug libstdc++/12658] Thread safety problems in locale::global() and locale::locale()

[pinskia at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |3.4.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12658

[Bug libstdc++/12658] Thread safety problems in locale::global() and locale::locale()

[peturr02 at ru dot is]

------- Additional Comments From peturr02 at ru dot is  2004-07-28 17:40 -------
The problem in locale::locale() is still present:

  __glibcxx_mutex_define_initialized(locale_cons_mutex);
  __glibcxx_mutex_define_initialized(locale_global_mutex);
} // namespace __gnu_internal

namespace std 
{
  using namespace __gnu_internal;

  locale::locale() throw() : _M_impl(0)
  { 
    _S_initialize();
    __gnu_cxx::lock sentry(__gnu_internal::locale_cons_mutex);
    _S_global->_M_add_reference();
    _M_impl = _S_global;
  }

  locale
  locale::global(const locale& __other)
  {
    _S_initialize();
    _Impl* __old;
    {
      __gnu_cxx::lock sentry(__gnu_internal::locale_global_mutex);
      __old = _S_global;
      __other._M_impl->_M_add_reference();
      _S_global = __other._M_impl;

Note that while locale::locale() and locale::global() both lock a mutex
before touching _S_global, they lock different mutexes. There is thus nothing
to stop one thread from executing locale::global() while another executes
locale::locale(). As already noted, this can (and does) lead to serious
problems.


-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|RESOLVED                    |REOPENED
         Resolution|FIXED                       |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12658

[Bug libstdc++/12658] Thread safety problems in locale::global() and locale::locale()

[peturr02 at ru dot is]

------- Additional Comments From peturr02 at ru dot is  2004-07-28 17:58 -------
Before anyone says "don't do that then" ...

This sort of usage can be perfectly safe (and sometimes even neccessary):

Thread 1 needs to do some formatting with some crufty C code, and thus needs
to set the global locale:

void thread1()
{
   // Set global locale to "C"
   locale tmp = locale::global(locale("C"));

   // Do some C style formatting
   fprintf(f, ...);

   // Reset global locale
   locale::global(tmp);
}

Thread 2 also needs to format, but uses IOstreams. Because thread 1 may be
playing games with the global locale, take care always to call imbue:

void thread2()
{
    // Thread specific locale
    locale myloc("");

    fstream f;
    // Take care not to use global locale, can't be trusted.
    f.imbue(myloc);

    // Do some C++ style formatting
    f << ...
}

The two threads don't share any user-visible data, so this sort of usage
should be thread-safe. The only problem is that fstream::fstream() will
call locale::locale(), which touches _S_global, a variable that the user
should need to know about.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12658

[Bug libstdc++/12658] Thread safety problems in locale::global() and locale::locale()

[pcarlini at suse dot de]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |pcarlini at suse dot de
   Last reconfirmed|2003-11-28 08:30:55         |2004-07-28 20:27:43
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12658

[Bug libstdc++/12658] Thread safety problems in locale::global() and locale::locale()

[pinskia at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|normal                      |minor
   Target Milestone|3.4.0                       |---


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12658

[Bug libstdc++/12658] Thread safety problems in locale::global() and locale::locale()

[peturr02 at ru dot is]

------- Additional Comments From peturr02 at ru dot is  2004-07-29 09:16 -------
> what about using just *one* mutex like in the attached??

Yes, that should fix it.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12658

[Bug libstdc++/12658] Thread safety problems in locale::global() and locale::locale()

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2004-07-29 15:54 -------
Subject: Bug 12658

CVSROOT:	/cvs/gcc
Module name:	gcc
Changes by:	paolo@gcc.gnu.org	2004-07-29 15:54:50

Modified files:
	libstdc++-v3   : ChangeLog 
	libstdc++-v3/src: locale_init.cc 

Log message:
	2004-07-29  Paolo Carlini  <pcarlini@suse.de>
	Petur Runolfsson  <peturr02@ru.is>
	
	PR libstdc++/12658 (continued)
	* src/locale_init.cc (locale::locale, locale::global): Use
	a single locale_mutex instead of two separate mutexes.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/ChangeLog.diff?cvsroot=gcc&r1=1.2590&r2=1.2591
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/src/locale_init.cc.diff?cvsroot=gcc&r1=1.14&r2=1.15



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12658

[Bug libstdc++/12658] Thread safety problems in locale::global() and locale::locale()

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2004-07-30 07:52 -------
Subject: Bug 12658

CVSROOT:	/cvs/gcc
Module name:	gcc
Branch: 	gcc-3_4-branch
Changes by:	paolo@gcc.gnu.org	2004-07-30 07:52:32

Modified files:
	libstdc++-v3   : ChangeLog 
	libstdc++-v3/src: locale_init.cc 
	libstdc++-v3/testsuite/22_locale/locale/cons: 12658_thread.cc 
	libstdc++-v3/testsuite/22_locale/num_put/put/char: 14220.cc 
	libstdc++-v3/testsuite/22_locale/num_put/put/wchar_t: 14220.cc 
	libstdc++-v3/docs/html/ext: lwg-active.html lwg-defects.html 

Log message:
	2004-07-30  Paolo Carlini  <pcarlini@suse.de>
	Petur Runolfsson  <peturr02@ru.is>
	
	PR libstdc++/12658 (continued)
	* src/locale_init.cc (locale::locale, locale::global): Use
	a single locale_mutex instead of two separate mutexes.
	
	2004-07-30  Paolo Carlini  <pcarlini@suse.de>
	
	* testsuite/22_locale/locale/cons/12658_thread.cc: Xfail: due to
	a bug in glibcs older than 2004-07-16, it can unpredictably fail
	irrespective of the correctness of libstdc++.
	
	2004-07-30  Benjamin Kosnik  <bkoz@redhat.com>
	
	* src/locale_init.cc: Use __gnu_cxx::lock.
	
	2004-07-30  Paolo Carlini  <pcarlini@suse.de>
	
	* testsuite/22_locale/num_put/put/char/14220.cc: Increase the value
	of precision: 10 is too small to actually trigger the bug.
	* testsuite/22_locale/num_put/put/wchar_t/14220.c: Likewise.
	
	2004-07-30  Paolo Carlini  <pcarlini@suse.de>
	
	* docs/html/ext/lwg-active.html, lwg-defects.html: Import Revision 31.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/ChangeLog.diff?cvsroot=gcc&only_with_tag=gcc-3_4-branch&r1=1.2224.2.149&r2=1.2224.2.150
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/src/locale_init.cc.diff?cvsroot=gcc&only_with_tag=gcc-3_4-branch&r1=1.6.4.4&r2=1.6.4.5
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/testsuite/22_locale/locale/cons/12658_thread.cc.diff?cvsroot=gcc&only_with_tag=gcc-3_4-branch&r1=1.2.2.1&r2=1.2.2.2
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/testsuite/22_locale/num_put/put/char/14220.cc.diff?cvsroot=gcc&only_with_tag=gcc-3_4-branch&r1=1.1.2.1&r2=1.1.2.2
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/testsuite/22_locale/num_put/put/wchar_t/14220.cc.diff?cvsroot=gcc&only_with_tag=gcc-3_4-branch&r1=1.1.2.1&r2=1.1.2.2
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/docs/html/ext/lwg-active.html.diff?cvsroot=gcc&only_with_tag=gcc-3_4-branch&r1=1.6.4.1&r2=1.6.4.2
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/docs/html/ext/lwg-defects.html.diff?cvsroot=gcc&only_with_tag=gcc-3_4-branch&r1=1.6.4.1&r2=1.6.4.2



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12658

[Bug libstdc++/12658] Thread safety problems in locale::global() and locale::locale()

[pcarlini at suse dot de]

------- Additional Comments From pcarlini at suse dot de  2004-07-30 08:25 -------
Fixed (again ;) everywhere.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|REOPENED                    |RESOLVED
         Resolution|                            |FIXED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12658

[Bug libstdc++/12658] Thread safety problems in locale::global() and locale::locale()

[pcarlini at suse dot de]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |3.4.2


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12658