[Bug libstdc++/11691] New: stdio_filebuf leaks FILE buffer when "no close" is requested

[Bug libstdc++/11691] New: stdio_filebuf leaks FILE buffer when "no close" is requested

[jeffbnews at nc dot rr dot com]

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

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11691

           Summary: stdio_filebuf leaks FILE buffer when "no close" is
                    requested
           Product: gcc
           Version: 3.3
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: libstdc++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: jeffbnews at nc dot rr dot com
                CC: gcc-bugs at gcc dot gnu dot org

This bug (?) can be re-created on Red Hat Linux 9.0
runnig GNUC > 3.


If I compile the code below (must be GNUC > 3), run it and
monitor the VmSize shown using /proc/<pid>/status, it
increases by 4kB every time through the loop.

I took a look at the source and it appears that fdopen is
called in __basic_file (with the file descriptor passed in,
stdout here for test purposes) and the resulting FILE* is
assigned to private variable _M_cfile.

If the third parameter in the stdio_filebuf ctor is set to
false, fclose is never called for _M_cfile, but the
FILE buffer/stream (_pointed to by _M_cfile) opened using
fdopen, isn't accessible, so the buffer is never freed.

It seems to me that if I pass in a fd and tell stdio_filebuf
not to close the file, it would still close the FILE buffer
or at least provide some way for me to access it so I can
call fclose when I'm done.  Since all I have is the fd
I passed in, all I can do is call close() ... which results
in the leak I mentioned.

Note that this was originally discover using fd's from a
pipe() call, I just used stdout to simplify the example.



#include <unistd.h>
#include <iostream>
#include <ext/stdio_filebuf.h>

int main()
{
  std::cout << "pid = " << getpid() << std::endl;


  for (int i=0; i<50; ++i)
  {
     __gnu_cxx::stdio_filebuf<char> filebuf(1,std::ios_base::out,false,1024);
     sleep(1);
  }
}

[Bug libstdc++/11691] stdio_filebuf leaks FILE buffer when "no close" is requested

[pinskia at physics dot uc dot edu]

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

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11691


pinskia at physics dot uc dot edu changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
   Last reconfirmed|0000-00-00 00:00:00         |2003-07-31 03:50:39
               date|                            |


------- Additional Comments From pinskia at physics dot uc dot edu  2003-07-31 03:50 -------
I can confirm the leak in the mainline (20030730), it is bad leak as if you remove the limit 
on the for loop and the sleep, the program leaks memory fast.

[Bug libstdc++/11691] stdio_filebuf leaks FILE buffer when "no close" is requested

[dhazeghi at yahoo dot com]

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

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11691


dhazeghi at yahoo dot com changed:

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

[Bug libstdc++/11691] stdio_filebuf leaks FILE buffer when "no close" is requested

[bkoz at gcc dot gnu dot org]

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11691

[Bug libstdc++/11691] stdio_filebuf leaks FILE buffer when "no close" is requested

[bkoz at gcc dot gnu dot org]

------- Additional Comments From bkoz at gcc dot gnu dot org  2003-12-05 23:57 -------

Ack. I added comments to the wrong bug. Let's try again:

----

I think the bool argument can just be removed: it was put in to deal with the
std streams (cin, cout, etc), and don't really apply to people using
stdio_filebuf for other work.

Or, I can keep the argument but have it do nothing (less impressive, but keeps
the same API). Here's a patch for the first idea, please let me know what you think.

best,
benjamin

2003-12-05  Benjamin Kosnik  <bkoz@redhat.com>

	PR libstdc++/11691 
	* include/ext/stdio_filebuf.h (stdio_filebuf::stdio_filebuf):
	Remove __del argument to file descriptor constructor.
	* config/io/basic_file_stdio.h (__basic_file::sys_open): Remove
	bool argument.
	* config/io/basic_file_stdio.cc: Same.

Index: config/io/basic_file_stdio.cc
===================================================================
RCS file: /cvs/gcc/gcc/libstdc++-v3/config/io/basic_file_stdio.cc,v
retrieving revision 1.23
diff -c -p -r1.23 basic_file_stdio.cc
*** config/io/basic_file_stdio.cc	22 Oct 2003 15:51:55 -0000	1.23
--- config/io/basic_file_stdio.cc	5 Dec 2003 23:43:21 -0000
*************** namespace std 
*** 140,147 ****
    }
    
    __basic_file<char>*
!   __basic_file<char>::sys_open(int __fd, ios_base::openmode __mode, 
! 			       bool __del) 
    {
      __basic_file* __ret = NULL;
      int __p_mode = 0;
--- 140,146 ----
    }
    
    __basic_file<char>*
!   __basic_file<char>::sys_open(int __fd, ios_base::openmode __mode)
    {
      __basic_file* __ret = NULL;
      int __p_mode = 0;
*************** namespace std 
*** 151,162 ****
      _M_open_mode(__mode, __p_mode, __rw_mode, __c_mode);
      if (!this->is_open() && (_M_cfile = fdopen(__fd, __c_mode)))
        {
! 	// Iff __del is true, then close will fclose the fd.
! 	_M_cfile_created = __del;
! 
  	if (__fd == 0)
  	  setvbuf(_M_cfile, reinterpret_cast<char*>(NULL), _IONBF, 0);
- 
  	__ret = this;
        }
      return __ret;
--- 150,158 ----
      _M_open_mode(__mode, __p_mode, __rw_mode, __c_mode);
      if (!this->is_open() && (_M_cfile = fdopen(__fd, __c_mode)))
        {
! 	_M_cfile_created = true;
  	if (__fd == 0)
  	  setvbuf(_M_cfile, reinterpret_cast<char*>(NULL), _IONBF, 0);
  	__ret = this;
        }
      return __ret;
*************** namespace std 
*** 199,205 ****
    __basic_file<char>* 
    __basic_file<char>::close()
    { 
!     __basic_file* __retval = static_cast<__basic_file*>(NULL);
      if (this->is_open())
        {
  	if (_M_cfile_created)
--- 195,201 ----
    __basic_file<char>* 
    __basic_file<char>::close()
    { 
!     __basic_file* __ret = static_cast<__basic_file*>(NULL);
      if (this->is_open())
        {
  	if (_M_cfile_created)
*************** namespace std 
*** 207,215 ****
  	else
  	  fflush(_M_cfile);
  	_M_cfile = 0;
! 	__retval = this;
        }
!     return __retval;
    }
   
    streamsize 
--- 203,211 ----
  	else
  	  fflush(_M_cfile);
  	_M_cfile = 0;
! 	__ret = this;
        }
!     return __ret;
    }
   
    streamsize 
Index: config/io/basic_file_stdio.h
===================================================================
RCS file: /cvs/gcc/gcc/libstdc++-v3/config/io/basic_file_stdio.h,v
retrieving revision 1.15
diff -c -p -r1.15 basic_file_stdio.h
*** config/io/basic_file_stdio.h	16 Oct 2003 22:37:48 -0000	1.15
--- config/io/basic_file_stdio.h	5 Dec 2003 23:43:21 -0000
***************
*** 1,6 ****
  // Wrapper of C-language FILE struct -*- C++ -*-
  
! // Copyright (C) 2000, 2001, 2002 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
--- 1,6 ----
  // Wrapper of C-language FILE struct -*- C++ -*-
  
! // Copyright (C) 2000, 2001, 2002, 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
*************** namespace std 
*** 74,80 ****
        sys_open(__c_file* __file, ios_base::openmode);
  
        __basic_file*
!       sys_open(int __fd, ios_base::openmode __mode, bool __del);
  
        __basic_file* 
        close(); 
--- 74,80 ----
        sys_open(__c_file* __file, ios_base::openmode);
  
        __basic_file*
!       sys_open(int __fd, ios_base::openmode __mode);
  
        __basic_file* 
        close(); 
Index: include/ext/stdio_filebuf.h
===================================================================
RCS file: /cvs/gcc/gcc/libstdc++-v3/include/ext/stdio_filebuf.h,v
retrieving revision 1.14
diff -c -p -r1.14 stdio_filebuf.h
*** include/ext/stdio_filebuf.h	12 Nov 2003 01:14:34 -0000	1.14
--- include/ext/stdio_filebuf.h	5 Dec 2003 23:43:22 -0000
*************** namespace __gnu_cxx
*** 65,78 ****
        /**
         *  @param  fd  An open file descriptor.
         *  @param  mode  Same meaning as in a standard filebuf.
-        *  @param  del  Whether to close the file on destruction.
         *  @param  size  Optimal or preferred size of internal buffer, in chars.
         *
         *  This constructor associates a file stream buffer with an open
!        *  POSIX file descriptor.  Iff @a del is true, then the associated
!        *  file will be closed when the stdio_filebuf is closed/destroyed.
        */
!       stdio_filebuf(int __fd, std::ios_base::openmode __mode, bool __del, 
  		    size_t __size = static_cast<size_t>(BUFSIZ));
  
        /**
--- 65,76 ----
        /**
         *  @param  fd  An open file descriptor.
         *  @param  mode  Same meaning as in a standard filebuf.
         *  @param  size  Optimal or preferred size of internal buffer, in chars.
         *
         *  This constructor associates a file stream buffer with an open
!        *  POSIX file descriptor.
        */
!       stdio_filebuf(int __fd, std::ios_base::openmode __mode, 
  		    size_t __size = static_cast<size_t>(BUFSIZ));
  
        /**
*************** namespace __gnu_cxx
*** 114,123 ****
  
    template<typename _CharT, typename _Traits>
      stdio_filebuf<_CharT, _Traits>::
!     stdio_filebuf(int __fd, std::ios_base::openmode __mode, bool __del, 
! 		  size_t __size)
      {
!       this->_M_file.sys_open(__fd, __mode, __del);
        if (this->is_open())
  	{
  	  this->_M_mode = __mode;
--- 112,120 ----
  
    template<typename _CharT, typename _Traits>
      stdio_filebuf<_CharT, _Traits>::
!     stdio_filebuf(int __fd, std::ios_base::openmode __mode, size_t __size)
      {
!       this->_M_file.sys_open(__fd, __mode);
        if (this->is_open())
  	{
  	  this->_M_mode = __mode;




-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11691

[Bug libstdc++/11691] stdio_filebuf leaks FILE buffer when "no close" is requested

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2003-12-07 03:46 -------
Subject: Bug 11691

CVSROOT:	/cvs/gcc
Module name:	gcc
Changes by:	bkoz@gcc.gnu.org	2003-12-07 03:46:14

Modified files:
	libstdc++-v3   : ChangeLog 
	libstdc++-v3/config/io: basic_file_stdio.cc basic_file_stdio.h 
	libstdc++-v3/include/ext: stdio_filebuf.h 

Log message:
	2003-12-06  Benjamin Kosnik  <bkoz@redhat.com>
	
	PR libstdc++/11691
	* include/ext/stdio_filebuf.h (stdio_filebuf::stdio_filebuf):
	Remove __del argument to file descriptor constructor.
	* config/io/basic_file_stdio.h (__basic_file::sys_open): Remove
	bool argument.
	* config/io/basic_file_stdio.cc: Same.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/ChangeLog.diff?cvsroot=gcc&r1=1.2131&r2=1.2132
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/config/io/basic_file_stdio.cc.diff?cvsroot=gcc&r1=1.23&r2=1.24
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/config/io/basic_file_stdio.h.diff?cvsroot=gcc&r1=1.15&r2=1.16
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/include/ext/stdio_filebuf.h.diff?cvsroot=gcc&r1=1.14&r2=1.15



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11691

[Bug libstdc++/11691] stdio_filebuf leaks FILE buffer when "no close" is requested

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2003-12-07 06:17 -------
Fixed for 3.4.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|                            |FIXED
   Target Milestone|---                         |3.4


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11691

[Bug libstdc++/11691] stdio_filebuf leaks FILE buffer when "no close" is requested

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2004-05-19 08:31 -------
Subject: Bug 11691

CVSROOT:	/cvs/gcc
Module name:	gcc
Changes by:	redi@gcc.gnu.org	2004-05-19 08:31:07

Modified files:
	libstdc++-v3   : ChangeLog 
	libstdc++-v3/include/ext: stdio_filebuf.h 

Log message:
	2004-05-18  Jonathan Wakely  <redi@gcc.gnu.org>
	
	* include/ext/stdio_filebuf.h: Update comments to reflect PR 11691.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/ChangeLog.diff?cvsroot=gcc&r1=1.2483&r2=1.2484
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/include/ext/stdio_filebuf.h.diff?cvsroot=gcc&r1=1.16&r2=1.17



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11691

[Bug libstdc++/11691] stdio_filebuf leaks FILE buffer when "no close" is requested

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2004-05-19 09:51 -------
Subject: Bug 11691

CVSROOT:	/cvs/gcc
Module name:	gcc
Branch: 	gcc-3_4-branch
Changes by:	redi@gcc.gnu.org	2004-05-19 09:51:36

Modified files:
	libstdc++-v3   : ChangeLog 
	libstdc++-v3/include/ext: stdio_filebuf.h 

Log message:
	2004-05-18  Jonathan Wakely  <redi@gcc.gnu.org>
	
	* include/ext/stdio_filebuf.h: Update comments to reflect PR 11691.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/ChangeLog.diff?cvsroot=gcc&only_with_tag=gcc-3_4-branch&r1=1.2224.2.107&r2=1.2224.2.108
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/include/ext/stdio_filebuf.h.diff?cvsroot=gcc&only_with_tag=gcc-3_4-branch&r1=1.16&r2=1.16.4.1



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11691