Reference cycle collector patch
| From: | David Wang | Date: | Mon, 08 Oct 2007 07:12:31 +0000 |
| Subject: | Reference cycle collector patch | ||
| Groups: | php.internals | ||
| Request: | Send a blank email to internals+get-32697@lists.php.net to get a copy of this message | ||
Hey all,
Now that macros for manipulating refcount and is_ref have been implemented, I’m ready to submit
patches for the GC. I know you all have been waiting for this for a long time ☺.
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
“experimental” 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’t 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 “always_inline”. 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.