Description:
------------
Using malloc/free in a multi-threaded process limits its scalability
because of the process-wide lock inside malloc/free. The scalability
of the PHP engine in a multi-threaded process can be improved by
reducing the use of malloc/free/strdup  and instead using
emalloc/efree/estrdup wherever possible (at least in the main request
processing code paths).

The code paths in TSRM/tsrm_virtual_cwd.c are invoked quite frequently
and they use malloc/free/strdup. I'd like to submit the following
patches (based on the PHP6 source tree) for review that incorporate
the use of emalloc/efree/estrdup in the virtual_cwd code paths. In
order to use emalloc/efree I had to relocate tsrm_virtual_cwd.c from
the TSRM directory to the Zend directory. I've split the change into 3
patches in order to make the changes easy to see

Avoid name clash between global and local variable
(http://bugs.php.net/bug.php?id=50101)
http://bitbucket.org/arvi/arviq/src/tip/arvi-08-namespace

Rename TSRM/tsrm_virtual_cwd.[ch] to Zend/zend_virtual_cwd.[ch]
http://bitbucket.org/arvi/arviq/src/tip/arvi-08-virtual_cwd

Replace malloc/free/strdup with emalloc/efree/estrdup
http://bitbucket.org/arvi/arviq/src/tip/arvi-08-virtual_cwd-emalloc


[http://marc.info/?l=php-internals&m=125846494007872&w=2]


Expected result:
----------------
Improved scalability on multi-threaded/multi-core systems.