Re: postgres.exe has encountered a problem on windows

On Fri, Apr 1, 2011 at 8:23 PM, Rushabh Lathia <rushabh.lathia@gmail.com>wrote:

On Fri, Apr 1, 2011 at 6:51 PM, Magnus Hagander <magnus@hagander.net>wrote:

On Fri, Apr 1, 2011 at 15:14, Rushabh Lathia <rushabh.lathia@gmail.com>
wrote:

Problem:
========

On windows when we run postgres.exe without any command line args, its
getting crash or its showing error into Application logs of Event

Viewer.

Analysis:
==========

For any stderr we call the write_stderr() and write_stderr() calls the
write_console() for stderr. Now here write_console() using the palloc()
internally, which require the CurrentMemoryContext.

At the startup CurrentMemoryContext will be NULL, so palloc again

calling

write_stderr(). So recursion has been started and its ending up with
exception.

Call stack for palloc() is:

main() -> check_root() -> write_stderr() -> write_console() ->
pgwin32_toUTF16() -> palloc()

Fix:
=====

Earlier we used to call vfprintf() for windows stderr, which is now
replaced with write_console().
So to avoid the exception now, I added condition for

CurrentMemoryContext

into write_stderr().

PFA patch to fix the same.

What about the cases where we directly call write_console()? Do we
know we are good there, or should the check perhaps be made inside
write_console() instead of in the caller?

Hmm, yes. It make more sense to add check for CurrentMemoryContext in
write_console().

PFA patch for the same.

Oops missed the attachment.

Here it is ..

On Fri, Apr 1, 2011 at 16:56, Rushabh Lathia <rushabh.lathia@gmail.com> wrote:

On Fri, Apr 1, 2011 at 8:23 PM, Rushabh Lathia <rushabh.lathia@gmail.com>
wrote:

On Fri, Apr 1, 2011 at 6:51 PM, Magnus Hagander <magnus@hagander.net>
wrote:

On Fri, Apr 1, 2011 at 15:14, Rushabh Lathia <rushabh.lathia@gmail.com>
wrote:

Problem:
========

On windows when we run postgres.exe without any command line args, its
getting crash or its showing error into Application logs of Event
Viewer.

Analysis:
==========

For any stderr we call the write_stderr() and write_stderr() calls the
write_console() for stderr. Now here write_console() using the palloc()
internally, which require the CurrentMemoryContext.

At the startup CurrentMemoryContext will be NULL, so palloc again
calling
write_stderr(). So recursion has been started and its ending up with
exception.

Call stack for palloc() is:

main() -> check_root() -> write_stderr() -> write_console() ->
pgwin32_toUTF16() -> palloc()

Fix:
=====

Earlier  we used to call vfprintf() for windows stderr, which is now
replaced with write_console().
So to avoid the exception now, I added condition for
CurrentMemoryContext
into write_stderr().

PFA patch to fix the same.

What about the cases where we directly call write_console()? Do we
know we are good there, or should the check perhaps be made inside
write_console() instead of in the caller?

Hmm, yes. It make more sense to add check for CurrentMemoryContext in
write_console().

PFA patch for the same.

Oops missed the attachment.

Here it is ..

Thanks, applied with the addition of a comment.

--
 Magnus Hagander
 Me: http://www.hagander.net/
 Work: http://www.redpill-linpro.com/

On Fri, Apr 1, 2011 at 11:31 PM, Magnus Hagander <magnus@hagander.net>wrote:

On Fri, Apr 1, 2011 at 16:56, Rushabh Lathia <rushabh.lathia@gmail.com>
wrote:

On Fri, Apr 1, 2011 at 8:23 PM, Rushabh Lathia <rushabh.lathia@gmail.com

wrote:

On Fri, Apr 1, 2011 at 6:51 PM, Magnus Hagander <magnus@hagander.net>
wrote:

On Fri, Apr 1, 2011 at 15:14, Rushabh Lathia <rushabh.lathia@gmail.com

wrote:

Problem:
========

On windows when we run postgres.exe without any command line args,

its

getting crash or its showing error into Application logs of Event
Viewer.

Analysis:
==========

For any stderr we call the write_stderr() and write_stderr() calls

the

write_console() for stderr. Now here write_console() using the

palloc()

internally, which require the CurrentMemoryContext.

At the startup CurrentMemoryContext will be NULL, so palloc again
calling
write_stderr(). So recursion has been started and its ending up with
exception.

Call stack for palloc() is:

main() -> check_root() -> write_stderr() -> write_console() ->
pgwin32_toUTF16() -> palloc()

Fix:
=====

Earlier we used to call vfprintf() for windows stderr, which is now
replaced with write_console().
So to avoid the exception now, I added condition for
CurrentMemoryContext
into write_stderr().

PFA patch to fix the same.

What about the cases where we directly call write_console()? Do we
know we are good there, or should the check perhaps be made inside
write_console() instead of in the caller?

Hmm, yes. It make more sense to add check for CurrentMemoryContext in
write_console().

PFA patch for the same.

Oops missed the attachment.

Here it is ..

Thanks, applied with the addition of a comment.

Thanks Magnus.

regards,
Rushabh Lathia
EnterpriseDB, The Enterprise PostgreSQL company.