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

Re: [PATCH] Re: 1.1rc1 performance regression in 'svn status' (and also 1.1rc2)

From: Philip Martin <philip_at_codematters.co.uk>
Date: 2004-08-17 22:37:04 CEST

"Peter N. Lundblad" <peter@famlundblad.se> writes:

>> > + handle_pool = svn_pool_create (NULL);
>>
>> This creates a pool in every thread, but I don't see the pool getting
>> cleared or destroyed. An application that creates threads continually
>> (e.g. threaded svnserve) will cause the number of pools to grow
>> without bound.
>>
> xlate_cleanup will take care of that. It is called when the thread is
> destoyed.

Unless you are planning to write some more code I don't understand.
xlate_cleanup appears to be applied to the pool passed to
svn_utf_initialize. That pool could well have a lifetime much longer
than the thread lifetime, typically I would expect the pool to last as
long as the application runs.

> Problems is, when I check the implementation of
> apr_threadkey_private_create, the destructor is only used on POSIX and
> netware systems, not on Windows/OS2. So on these platforms, it is a leak
> after all. Maybe there is no way to register cleanups on these
> platforms,. This should have been documented in the APR headers!!!
>
>> > + handle_hash = apr_hash_make (pool);
>> > + if (apr_threadkey_private_set (handle_hash, xlate_handle_key)
>>
>> If pool is cleared handle_hash will become invalid, but will still be
>> referenced by the thread private data. The next time the thread calls
>> get_xlate_handle it will crash, or do something worse.
>>
> When the pool is cleared, the thread is dying, so the TSD for that thread
> isn't used again. This would be true where the pool is destroyed at all...

Again I don't understand. pool is an argument to one of the
svn_utf_xxx_(to/from)_xxx functions, it could well have a lifetime
much shorter than the thread and may well get repeatedly cleared.

-- 
Philip Martin
---------------------------------------------------------------------
To unsubscribe, e-mail: dev-unsubscribe@subversion.tigris.org
For additional commands, e-mail: dev-help@subversion.tigris.org
Received on Tue Aug 17 22:37:18 2004

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