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Date: Mon, 8 Oct 2007 00:12:31 -0700
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Subject: Reference cycle collector patch
From: planetbeing@gmail.com ("David Wang")

Hey all,

Now that macros for manipulating refcount and is_ref have been =
implemented, I=E2=80=99m ready to submit patches for the GC. I know you =
all have been waiting for this for a long time =E2=98=BA.

I have made two sets of patches, one for HEAD and one for PHP_5_3 (note =
that I had to rearrange the order of definitions and #includes in zend.h =
to get around a recursive dependency problem):

http://zoo.cs.yale.edu/~yw226/gc/gc6.diff.txt
http://zoo.cs.yale.edu/~yw226/gc/gc5_3.diff.txt

After applying those, these two files should be placed in the Zend =
subdirectory:

http://zoo.cs.yale.edu/~yw226/gc/zend_gc.c
http://zoo.cs.yale.edu/~yw226/gc/zend_gc.h

For those who were following the progress of the GC through the =
incubator SVN, the GC implemented with these patches is DIFFERENT than =
the one currently in the SVN tree. They are from an =
=E2=80=9Cexperimental=E2=80=9D branch that I believed was more tolerant =
of the zval juggling PHP and its extensions sometimes like to do. It =
turned out to be very successful, but I hadn=E2=80=99t bothered =
remerging it.

I highly recommend these two patches in addition (but they are optional =
for GC functioning):

http://zoo.cs.yale.edu/~yw226/gc/alwaysinline6.diff.txt
http://zoo.cs.yale.edu/~yw226/gc/alwaysinline5_3.diff.txt

These are meant to be applied after the previous patches. These simply =
change all the inline functions in the Zend engine to =
=E2=80=9Calways_inline=E2=80=9D. Zend object files can become seriously =
oversized and this makes the compiler silently ignore the inline =
keyword. Changing this to always_inline (defined in zend.h) forces the =
compiler to inline the function or at least give a warning if it cannot.

The reason I bring up the issue here is that my patch is known to =
sometimes push object files that were just under the internal compiler =
limit over the edge and make the compiler refuse to inline. This has the =
effect of making the whole Zend engine disproportionately slower.

Anyway, please try these out and tell me how it goes!


David

P.S. This patch has the GC enabled by default.