[svn.haxx.se] · SVN Dev · SVN Users · SVN Org · TSVN Dev · TSVN Users · Subclipse Dev · Subclipse Users · this month's index

RE: svn commit: r990537 - /subversion/branches/performance/subversion/libsvn_subr/svn_temp_ser ializer.c

From: Bert Huijben <bert_at_qqmail.nl>
Date: Mon, 30 Aug 2010 09:31:03 +0200

> -----Original Message-----
> From: Daniel Shahaf [mailto:d.s_at_daniel.shahaf.name]
> Sent: zondag 29 augustus 2010 16:36
> To: Johan Corveleyn
> Cc: dev_at_subversion.apache.org; stefan2_at_apache.org
> Subject: Re: svn commit: r990537 -
> /subversion/branches/performance/subversion/libsvn_subr/svn_temp_ser
> ializer.c
>
> Johan Corveleyn wrote on Sun, Aug 29, 2010 at 16:24:24 +0200:
> > Hi Stefan,
> >
> > On Sun, Aug 29, 2010 at 12:32 PM, <stefan2_at_apache.org> wrote:
> > > Author: stefan2
> > > Date: Sun Aug 29 10:32:08 2010
> > > New Revision: 990537
> > >
> > > URL: http://svn.apache.org/viewvc?rev=990537&view=rev
> > > Log:
> > > Looking for the cause of Johan Corveleyn's crash (see
> > > http://svn.haxx.se/dev/archive-2010-08/0652.shtml), it
> > > seems that wrong / corrupted data contains backward
> > > pointers, i.e. negative offsets. That cannot happen if
> > > everything works as intended.
> >
> > I've just retried my test after this change (actually with
> > performance-branch_at_990579, so updated just 10 minutes ago). Now I get
> > the assertion error, after running log or blame on that particular
> > file:
> >
> > [[[
> > $ svnserve -d -r c:/research/svn/experiment/repos
> > Assertion failed: *ptr > buffer, file
> > ..\..\..\subversion\libsvn_subr\svn_temp_serializer.c, line 282
> >
> > This application has requested the Runtime to terminate it in an unusual
> way.
> > Please contact the application's support team for more information.
> > ]]]
> >
> > Is there any way I can find more information about this failure, so I
> > can help you diagnose the problem?
> >
>
> s/assert/SVN_ERR_MALFUNCTION_NO_RETURN/

assert and SVN_ERR_MALFUNCTION() have their own use.

assert() is only evaluated in Maintainer/DEBUG mode and isn't evaluated at
runtime for normal users. So this assertion is good for tests that are too
slow for general use or for things that shouldn't happen but are not really
an error.
E.g. it is used through svn_dirent_*(), svn_uri_*(), etc.
[A url is really just a valid unix path which can be canonicalized by
removing double slashes, but using it is in almost every case a user error.
So this triggers a maintainer/debug only assertion]

This allows easier debugging of these errors.

SVN_ERR_MALFUNCTION() and SVN_ERR_ASSERT() are for tests that also need
evaluation in release mode. The fatal error is avoidable by installing a
error callback.

The SVN_ERR_MALFUNCTION_NO_RETURN and SVN_ERR_ASSERT_NO_RETURN() function
should be avoided (real fix: Make the function return svn_error_t*) as these
will trigger an error and then an abort at runtime. So it will CRASH third
party application when this error occurs there.

        Bert
Received on 2010-08-30 09:31:48 CEST

This is an archived mail posted to the Subversion Dev mailing list.