In HHVM we've been piggybacking resources on the KindOfObject machinery.
At the language level, resource is considered to be a different type than
object, and there are a number of differences in behavior between objects
and resources (ex. resources don't allow for dynamic properties, resources
don't work with the clone operator, the "(object)" cast behaves differently
for resources vs. objects, etc).
Piggybacking resources on the KindOfObject machinery has some downsides.
Code that deals with KindOfObject values often needs to check if the value
is a resource and go down a different code path. This makes things harder
to maintain and harder to keep parity with Zend. Also, these extra branches
hurt performance a little, and they make it harder for the JIT to do a good
job in some cases when its generating machine code that operates on objects.
This diff introduces a new DataType called "KindOfResource", it separates
ResourceData from ObjectData's inheritance hierarchy, introduces a new
smart pointer types called "Resource" and "SmartResource", updates the
runtime as appropriate, and kills some more dead code in ObjectData and
ResourceData. I've tried to keep behavior the same for the most part and
resisted the urge to fix existing bugs with resources.
This is an incremental step towards moving it all the way
to hphp/server. This flattens base but doesn't untangle
the server files from lib_hphp_runtime
I was learning from @jdelong and he said that you should use
double quotes for local includes and angle brackets for library
includes. I asked why our code was the way it was, and he said he wanted
to clean it up. I beat him to it :)
Conflicts:
hphp/runtime/base/server/admin_request_handler.cpp
hphp/runtime/vm/named_entity.h
This change is mostly for FB internal organizational reasons.
Building is not effected beyond the fact that the target now
lands in hphp/hhvm/hhvm rather than src/hhvm/hhvm.
Jordan DeLong